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Sample records for high performance cell

  1. High Performance Perovskite Solar Cells.

    PubMed

    Tong, Xin; Lin, Feng; Wu, Jiang; Wang, Zhiming M

    2016-05-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long-term stable all-solid-state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost-effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole-transporting materials (HTMs) and electron-transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction.

  2. High Performance Perovskite Solar Cells

    PubMed Central

    Tong, Xin; Lin, Feng; Wu, Jiang

    2015-01-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long‐term stable all‐solid‐state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost‐effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole‐transporting materials (HTMs) and electron‐transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction. PMID:27774402

  3. Achieving High Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2015-03-01

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

  4. Towards high performance inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Gong, Xiong

    2013-03-01

    Bulk heterojunction polymer solar cells that can be fabricated by solution processing techniques are under intense investigation in both academic institutions and industrial companies because of their potential to enable mass production of flexible and cost-effective alternative to silicon-based electronics. Despite the envisioned advantages and recent technology advances, so far the performance of polymer solar cells is still inferior to inorganic counterparts in terms of the efficiency and stability. There are many factors limiting the performance of polymer solar cells. Among them, the optical and electronic properties of materials in the active layer, device architecture and elimination of PEDOT:PSS are the most determining factors in the overall performance of polymer solar cells. In this presentation, I will present how we approach high performance of polymer solar cells. For example, by developing novel materials, fabrication polymer photovoltaic cells with an inverted device structure and elimination of PEDOT:PSS, we were able to observe over 8.4% power conversion efficiency from inverted polymer solar cells.

  5. High performance zinc air fuel cell stack

    NASA Astrophysics Data System (ADS)

    Pei, Pucheng; Ma, Ze; Wang, Keliang; Wang, Xizhong; Song, Mancun; Xu, Huachi

    2014-03-01

    A zinc air fuel cell (ZAFC) stack with inexpensive manganese dioxide (MnO2) as the catalyst is designed, in which the circulation flowing potassium hydroxide (KOH) electrolyte carries the reaction product away and acts as a coolant. Experiments are carried out to investigate the characteristics of polarization, constant current discharge and dynamic response, as well as the factors affecting the performance and uniformity of individual cells in the stack. The results reveal that the peak power density can be as high as 435 mW cm-2 according to the area of the air cathode sheet, and the influence factors on cell performance and uniformity are cell locations, filled state of zinc pellets, contact resistance, flow rates of electrolyte and air. It is also shown that the time needed for voltages to reach steady state and that for current step-up or current step-down are both in milliseconds, indicating the ZAFC can be excellently applied to vehicles with rapid dynamic response demands.

  6. High performance vapour-cell frequency standards

    NASA Astrophysics Data System (ADS)

    Gharavipour, M.; Affolderbach, C.; Kang, S.; Bandi, T.; Gruet, F.; Pellaton, M.; Mileti, G.

    2016-06-01

    We report our investigations on a compact high-performance rubidium (Rb) vapour-cell clock based on microwave-optical double-resonance (DR). These studies are done in both DR continuous-wave (CW) and Ramsey schemes using the same Physics Package (PP), with the same Rb vapour cell and a magnetron-type cavity with only 45 cm3 external volume. In the CW-DR scheme, we demonstrate a DR signal with a contrast of 26% and a linewidth of 334 Hz; in Ramsey-DR mode Ramsey signals with higher contrast up to 35% and a linewidth of 160 Hz have been demonstrated. Short-term stabilities of 1.4×10-13 τ-1/2 and 2.4×10-13 τ-1/2 are measured for CW-DR and Ramsey-DR schemes, respectively. In the Ramsey-DR operation, thanks to the separation of light and microwave interactions in time, the light-shift effect has been suppressed which allows improving the long-term clock stability as compared to CW-DR operation. Implementations in miniature atomic clocks are considered.

  7. High performance polymer tandem solar cell

    PubMed Central

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

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells. PMID:26669577

  8. High performance internal reforming unit for high temperature fuel cells

    DOEpatents

    Ma, Zhiwen [Sandy Hook, CT; Venkataraman, Ramakrishnan [New Milford, CT; Novacco, Lawrence J [Brookfield, CT

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  9. Toward High Performance Photovoltaic Cells based on Conjugated Polymers

    DTIC Science & Technology

    2016-12-26

    AFRL-AFOSR-JP-TR-2016-0103 Toward High Performance Photovoltaic Cells based on Conjugated Polymers Kung-Hwa Wei National Chiao Tung University Final...REPORT TYPE Final 3. DATES COVERED (From - To) 16 Sep 2015 to 15 Sep 2016 4. TITLE AND SUBTITLE Toward High Performance Photovoltaic Cells based on...Grant 15IOA0113 “Toward High Performance Photovoltaic Cells Based on Conjugated Polymers (Taiwan side)” Dec. 16, 2016 PI information: Kung-Hwa Wei

  10. Life-cycle costs of high-performance cells

    NASA Technical Reports Server (NTRS)

    Daniel, R.; Burger, D.; Reiter, L.

    1985-01-01

    A life cycle cost analysis of high efficiency cells was presented. Although high efficiency cells produce more power, they also cost more to make and are more susceptible to array hot-spot heating. Three different computer analysis programs were used: SAMICS (solar array manufacturing industry costing standards), PVARRAY (an array failure mode/degradation simulator), and LCP (lifetime cost and performance). The high efficiency cell modules were found to be more economical in this study, but parallel redundancy is recommended.

  11. High performance direct methanol fuel cell with thin electrolyte membrane

    NASA Astrophysics Data System (ADS)

    Wan, Nianfang

    2017-06-01

    A high performance direct methanol fuel cell is achieved with thin electrolyte membrane. 320 mW cm-2 of peak power density and over 260 mW cm-2 at 0.4 V are obtained when working at 90 °C with normal pressure air supply. It is revealed that the increased anode half-cell performance with temperature contributes primarily to the enhanced performance at elevated temperature. From the comparison of iR-compensated cathode potential of methanol/air with that of H2/air fuel cell, the impact of methanol crossover on cathode performance decreases with current density and becomes negligible at high current density. Current density is found to influence fuel efficiency and methanol crossover significantly from the measurement of fuel efficiency at different current density. At high current density, high fuel efficiency can be achieved even at high temperature, indicating decreased methanol crossover.

  12. Performance Characterization of High Energy Commercial Lithium-ion Cells

    NASA Technical Reports Server (NTRS)

    Schneidegger, Brianne T.

    2010-01-01

    The NASA Glenn Research Center Electrochemistry Branch performed characterization of commercial lithium-ion cells to determine the cells' performance against Exploration Technology Development Program (ETDP) Key Performance Parameters (KPP). The goals of the ETDP Energy Storage Project require significant improvements in the specific energy of lithium-ion technology over the state-of-the-art. This work supports the high energy cell development for the Constellation customer Lunar Surface Systems (LSS). In support of these goals, testing was initiated in September 2009 with high energy cylindrical cells obtained from Panasonic and E-One Moli. Both manufacturers indicated the capability of their cells to deliver specific energy of at least 180 Wh/kg or higher. Testing is being performed at the NASA Glenn Research Center to evaluate the performance of these cells under temperature, rate, and cycling conditions relevant to the ETDP goals for high energy cells. The cell-level specific energy goal for high energy technology is 180 Wh/kg at a C/10 rate and 0 C. The threshold value is 165 Wh/kg. The goal is to operate for at least 2000 cycles at 100 percent DOD with greater than 80 percent capacity retention. The Panasonic NCR18650 cells were able to deliver nearly 200 Wh/kg at the aforementioned conditions. The E-One Moli ICR18650J cells also met the specific energy goal by delivering 183 Wh/kg. Though both cells met the goal for specific energy, this testing was only one portion of the testing required to determine the suitability of commercial cells for the ETDP. The cells must also meet goals for cycle life and safety. The results of this characterization are summarized in this report.

  13. 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.

  14. High-performance multiple-donor bulk heterojunction solar cells

    SciTech Connect

    Yang, Yang; Chen, Wei; Dou, Letian; Chang, Wei-Hsuan; Duan, Hsin-Sheng; Bob, Brion; Li, Gang; Yang, Yang

    2015-02-09

    Broadening the absorption bandwidth of polymer solar cells by incorporating multiple absorber donors into the bulk-heterojunction active layer is an attractive means of resolving the narrow absorption of organic semiconductors. However, this leads to a much more complicated system, and previous efforts have met with only limited success. Here, several dual-donor and multi-donor bulk-heterojunction polymer solar cells based on a pool of materials with different absorption ranges and preferred molecular structures were studied. The study shows clearly that compatible polymer donors can coexist harmoniously, but the mixing of incompatible polymers can lead to severe molecular disorder and limit device performance. These results provide guidance for the general use of multiple-donor bulk heterojunctions to overcome the absorption limitation and achieve both high performance and fabrication simplicity for organic solar cells.

  15. Rapid prototype fabrication processes for high-performance thrust cells

    NASA Technical Reports Server (NTRS)

    Hunt, K.; Chwiedor, T.; Diab, J.; Williams, R.

    1994-01-01

    The Thrust Cell Technologies Program (Air Force Phillips Laboratory Contract No. F04611-92-C-0050) is currently being performed by Rocketdyne to demonstrate advanced materials and fabrication technologies which can be utilized to produce low-cost, high-performance thrust cells for launch and space transportation rocket engines. Under Phase 2 of the Thrust Cell Technologies Program (TCTP), rapid prototyping and investment casting techniques are being employed to fabricate a 12,000-lbf thrust class combustion chamber for delivery and hot-fire testing at Phillips Lab. The integrated process of investment casting directly from rapid prototype patterns dramatically reduces design-to-delivery cycle time, and greatly enhances design flexibility over conventionally processed cast or machined parts.

  16. Comprehensive design of omnidirectional high-performance perovskite solar cells

    PubMed Central

    Zhang, Yutao; Xuan, Yimin

    2016-01-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight. PMID:27405419

  17. Comprehensive design of omnidirectional high-performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Yutao; Xuan, Yimin

    2016-07-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight.

  18. Comprehensive design of omnidirectional high-performance perovskite solar cells.

    PubMed

    Zhang, Yutao; Xuan, Yimin

    2016-07-13

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight.

  19. Recent advances in high-performance direct methanol fuel cells

    SciTech Connect

    Narayanan, S.R.; Chun, W.; Valdez, T.I.

    1996-12-31

    Direct methanol fuel cells for portable power applications have been advanced significantly under DARPA- and ARO-sponsored programs over the last five years. A liquid-feed direct methanol fuel cell developed under these programs, employs a proton exchange membrane as electrolyte and operates on aqueous solutions of methanol with air or oxygen as the oxidant. Power densities as high as 320 mW/cm{sup 2} have been demonstrated. Demonstration of five-cell stack based on the liquid-feed concept have been successfully performed by Giner Inc. and the Jet Propulsion Laboratory. Over 2000 hours of life-testing have been completed on these stacks. These fuel cells have been also been demonstrated by USC to operate on alternate fuels such as trimethoxymethane, dimethoxymethane and trioxane. Reduction in the parasitic loss of fuel across the fuel cell, a phenomenon termed as {open_quotes}fuel crossover{close_quotes} has been achieved using polymer membranes developed at USC. As a result efficiencies as high as 40% is considered attainable with this type of fuel cell. The state-of-development has reached a point where it is now been actively considered for stationary, portable and transportation applications. The research and development issues have been the subject of several previous articles and the present article is an attempt to summarize the key advances in this technology.

  20. Development of high performance sodium/metal chloride cells

    NASA Astrophysics Data System (ADS)

    Vissers, D. R.; Bloom, I. D.; Hash, M. C.; Redey, L.; Hammer, C. L.; Dees, D. W.; Nelson, P. A.

    Sodium/metal chloride (MCl2) cells and batteries are being studied at Argonne National Laboratory (ANL) for stationary energy storage and transportation applications. The work is being directed toward (1) development of thin, high capacity density electrodes and inexpensive beta double prime alumina-glass composite electrolyte materials to replace beta double prime alumina, and (2) the development of models to project MCl2 system performances. In our NiCl2 electrode work, the effects of charge/discharge rates, temperature, electrode porosity, and sulfur content on electrode performance were determined using annular electrodes fabricated in the uncharged state. Of all electrode design parameters mentioned, electrode porosity, sulfur content, and charge rates have the greatest effect on utilization and on the area-specific impedance. The beta double prime alumina-glass composite electrolyte work has led to the development of a highly conductive (3.3 x 10(exp -2)S/cm at 250 C) composite material. Preliminary modeling studies indicate that the performance of the MCl2 electrodes can be fitted by a mathematic model very successfully and that cell electrolyte configurations of either multiple tubes joined at a header or compartmented flat structures of either beta double prime alumina or of the composite material would result in high performance batteries with power-to-energy ratios of about 5.

  1. High-performance polymer photovoltaic cells and photodetectors

    NASA Astrophysics Data System (ADS)

    Yu, Gang; Srdanov, Gordana; Wang, Hailiang; Cao, Yong; Heeger, Alan J.

    2001-02-01

    Polymer photovoltaic cells and photodetectors have passed their infancy and become mature technologies. The energy conversion efficiency of polymer photovoltaic cells have been improved to over 4.1% (500 nm, 10 mW/cm2). Such high efficiency polymer photovoltaic cells are promising for many applications including e-papers, e-books and smart- windows. The development of polymer photodetectors is even faster. The performance parameters have been improved to the level meeting all specifications for practical applications. The polymer photodetectors are of high photosensitivity (approximately 0.2 - 0.3 A/Watt in visible and UV), low dark current (0.1 - 1 nA/cm2), large dynamic range (> 8 orders of magnitude), linear intensity dependence, low noise level and fast response time (to nanosecond time domain). These devices show long shelf and operation lives. The advantages of low manufacturing cost, large detection area, and easy hybridization and integration with other electronic or optical components make the polymer photodetectors promising for a variety of applications including chemical/biomedical analysis, full-color digital image sensing and high energy radiation detection.

  2. High-performing vapor-cell frequency standards

    NASA Astrophysics Data System (ADS)

    Godone, A.; Levi, F.; Calosso, C. E.; Micalizio, S.

    2015-03-01

    Many nowadays scientific and technological applications need very precise time and frequency reference signals. Very often, only atomic clocks can guarantee the high level of accuracy and stability required by these signals. In the current scenario of atomic frequency standards, vapor-cell clocks are particularly suited to be employed in those activities that demand good frequency stability performances joined to compactness, reliability and low power consumption. Recently, due to better-performing laser sources and to innovative techniques to prepare and detect the atoms, several cell-based prototypes exhibiting unprecedented frequency stability have been developed. We review advances in the field of laser-pumped vapor-cell clocks and we provide an overview of the techniques that allowed to achieve frequency stabilities in the order of 1×10-13 at 1s (short term) and in the range of 10-15 for the medium-long term. These stabilities are two orders of magnitude better than current commercial Rb clocks. We also prospect the possibility of further improving these results.

  3. High Performance InGaAsSb TPV Cells

    NASA Astrophysics Data System (ADS)

    Shellenbarger, Zane A.; Taylor, Gordon C.; Martinelli, Ramon U.; Carpinelli, Joseph M.

    2004-11-01

    Lattice-matched 0.52 eV InGaAsSb/GaSb thermophotovoltaic (TPV) cells are grown using a multi-wafer metal-organic-chemical-vapor-deposition (MOCVD) system. MOCVD growth series of P/N junction epitaxial structures consisting of as many as 30 wafers demonstrate good run-to-run reproducibility, good uniformity across the wafer and exhibit high performance with open circuit voltages of ˜300mV and fill factors of 70% at 25°C. Growth parameters, including temperature, surface preparation and substrate orientation, that directly affect growth have been optimized for the active 0.52 eV InGaAsSb region and GaSb confinement layers. Focus is on increasing TPV diode performance through architectural improvements, specifically by reducing the minority carrier recombination velocity at the emitter and base front and back interfaces. Work in support of incorporating a back surface reflector (BSR) including the growth of N/P diode architectures and the addition of a lattice-matched InAsSb etch stop layer for substrate removal and wafer bonding, is reported. The lattice matched InAsSb stop etch exhibits resiliency to the substrate removal and wafer bonding processes. Substantial improvement in carrier lifetime on test structures with P-type AlGaAsSb layers indicated incorporation of these layers into the TPV cell structure should provide significant improvement in open-circuit voltage. Addition of AlGaAsSb confinement layers to the standard P/N cell structure gave some of the best InGaAsSb TPV cell results to date.

  4. High performance, high bandgap, lattice-mismatched, GaInP solar cells

    SciTech Connect

    Wanlass, Mark W; Carapella, Jeffrey J; Steiner, Myles A

    2016-11-01

    High performance, high bandgap, lattice-mismatched, photovoltaic cells (10), both transparent and non-transparent to sub-bandgap light, are provided as devices for use alone or in combination with other cells in split spectrum apparatus or other applications.

  5. High performance, high bandgap, lattice-mismatched, GaInP solar cells

    DOEpatents

    Wanlass, Mark W.; Carapella, Jeffrey J.; Steiner, Myles A.

    2014-07-08

    High performance, high bandgap, lattice-mismatched, photovoltaic cells (10), both transparent and non-transparent to sub-bandgap light, are provided as devices for use alone or in combination with other cells in split spectrum apparatus or other applications.

  6. Theoretical and experimental considerations for high silicon solar cell performance

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.; Keavney, C. J.; Geoffroy, L. M.

    1986-01-01

    This paper reviews ongoing research aimed at the attainment of highly efficient silicon solar cells. The importance of low-recombination highly-doped n(+) and p(+) regions and the manner in which such regions are fabricated are discussed. Theoretical light-trapping considerations are combined with experimental reflectance data to show that high quantum efficiency may be obtained from thin (100-micron) cells. The principal finding of this work is that thin solar cells with conversion efficiencies of over 20 percent may be fabricated if recombination at the front and back metal/silicon interfaces is reduced. Large-area cells (53 sq cm) with an efficiency of 18 percent are reported.

  7. Engineering high performance intermediate temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Ahn, Jin Soo

    Solid oxide fuel cells (SOFCs) are an efficient, fuel flexible energy conversion device, capable of operating on fuels ranging from natural gas to gasoline, diesel, and biofuels, as well as hydrogen. However, to this point the marketability of SOFCs has been limited by their high operating temperatures. Achieving high power at intermediate temperatures (IT, 500 -- 700 °C) would be a significant breakthrough, as low temperature operation would result in better stability and allow for a broader range of material options for the SOFC components as well as the balance of plant, such as stainless steel interconnects (which are only viable at <700 °C). Thus far, power densities on the order of 2 W/cm2 have been limited to temperatures above 800 °C. This dissertation contains a series of works to realize exceptionally high power at IT ranges. First, improved fabrication techniques including anode tapecasting and electrolyte spray coating were developed, and a molecular approach to anode functional layer (AFL) was employed using precursor solutions. This newly developed AFL reduced the ASR of a SOFC sample by 60 % and increased the open circuit potential (OCP) by more than 0.1 V resulting in a 140 % increase in power. Further investigations into this molecular AFL showed that a multilayered AFL can further reduce the ASR and increase the maximum power density. Secondly, the potential use of Sm0.075Nd0.075Ce0.85O 2-delta as an electrolyte has been investigated. The current-voltage (I-V) performance of the cell exhibits a maximum power density reaching 1.38 W/cm2 with an area specific resistance (ASR) of 0.087 Ocm 2 at 650 °C with 90 sccm of air and wet hydrogen. Also, the high OCP achieved at 500 °C (0.96 V) as well as the high performance confirmed the viability of Sm0.075Nd0.075Ce0.85 O2-delta as an alternative electrolyte material. The cathode used for this study was La0.6Sr0.4Co0.2Fe 0.8O3 (LSCF) -- Gd0.1Ce0.9O 2 (GDC) composite. Finally, Er0.8Bi1.2O3 (ESB

  8. Contribution of Nanostructures in High Performance Solar Cells

    NASA Astrophysics Data System (ADS)

    Aly, Abouelmaaty M.; Ebrahim, Essamudin A.; Sweelem, Emad

    2017-08-01

    Nanotechnology has great contributions in various fields, especially in solar energy conversion through solar cells (SCs). Nanostructured SCs can provide high performance with lower fabrication costs. The transition from fossil fuel energy to renewable sustainable energy represents a major technological challenge for the world. In the last years, the industry of SCs has grown rapidly due to strong attention in renewable energy in order to handle the problem of global climate change that is now believed to occur due to use of the fossil fuels. Cost is an influential factor in the eventual success of any solar technology, since inexpensive SCs are needed to produce electricity, especially for rural areas and for third world countries. Therefore, new developments in nanotechnology may open the door for the production of inexpensive and more efficient SCs by reducing the manufacturing costs of SCs. Utilizing nanotechnology in cheaper SCs will help maintain the environment. This article covers a review of the progress that has been made to-date to enhance efficiencies of various nanostructures used in SCs, including utilizations of all the wavelengths present in of the solar spectrum.

  9. Cell-Dock: high-performance protein-protein docking.

    PubMed

    Pons, Carles; Jiménez-González, Daniel; González-Álvarez, Cecilia; Servat, Harald; Cabrera-Benítez, Daniel; Aguilar, Xavier; Fernández-Recio, Juan

    2012-09-15

    The application of docking to large-scale experiments or the explicit treatment of protein flexibility are part of the new challenges in structural bioinformatics that will require large computer resources and more efficient algorithms. Highly optimized fast Fourier transform (FFT) approaches are broadly used in docking programs but their optimal code implementation leaves hardware acceleration as the only option to significantly reduce the computational cost of these tools. In this work we present Cell-Dock, an FFT-based docking algorithm adapted to the Cell BE processor. We show that Cell-Dock runs faster than FTDock with maximum speedups of above 200×, while achieving results of similar quality. The source code is released under GNU General Public License version 2 and can be downloaded from http://mmb.pcb.ub.es/~cpons/Cell-Dock. djimenez@ac.upc.edu or juanf@bsc.es Supplementary data are available at Bioinformatics online.

  10. Long-life high performance fuel cell program

    NASA Technical Reports Server (NTRS)

    Martin, R. E.

    1985-01-01

    A multihundred kilowatt Regenerative Fuel Cell for use in a space station is envisioned. Three 0.508 sq ft (471.9 cm) active area multicell stacks were assembled and endurance tested. The long term performance stability of the platinum on carbon catalyst configuration suitability of the lightweight graphite electrolyte reservoir plate, the stability of the free standing butyl bonded potassium titanate matrix structure, and the long life potential of a hybrid polysulfone cell edge frame construction were demonstrated. A 18,000 hour demonstration test of multicell stack to a continuous cyclical load profile was conducted. A total of 12,000 cycles was completed, confirming the ability of the alkaline fuel cell to operate to a load profile simulating Regenerative Fuel Cell operation. An orbiter production hydrogen recirculation pump employed in support of the cyclical load profile test completed 13,000 hours of maintenance free operation. Laboratory endurance tests demonstrated the suitability of the butyl bonded potassium matrix, perforated nickel foil electrode substrates, and carbon ribbed substrate anode for use in the alkaline fuel cell. Corrosion testing of materials at 250 F (121.1 C) in 42% wgt. potassium identified ceria, zirconia, strontium titanate, strontium zirconate and lithium cobaltate as candidate matrix materials.

  11. Effects of high doping levels on silicon solar cell performance

    NASA Technical Reports Server (NTRS)

    Godlewski, M. P.; Brandhorst, H. W., Jr.; Baraona, C. R.

    1975-01-01

    Open-circuit voltages measured in silicon solar cells made from 0.01 ohm-cm material are 150 mV lower than voltages calculated from simple diffusion theory and cannot be explained by poor diffusion lengths or surface leakage currents. An analytical study was made to determine whether high doping effects, which increase the intrinsic carrier concentration, could account for the low observed voltages and to determine the limits on voltage and efficiency imposed by high doping effects. The results indicate that the observed variation of voltage with base resistivity is predicted by these effects. A maximum efficiency of 19% (AMO) and a voltage of 0.7 volts were calculated for 0.1 ohm-cm cells assuming an optimum diffused layer impurity profile.

  12. High performance nickel-cadmium cells for electric vehicles

    NASA Astrophysics Data System (ADS)

    Cornu, Jean-Pierre

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

  13. High performance, inexpensive solar cell process capable of a high degree of automation

    NASA Technical Reports Server (NTRS)

    Shah, P.; Fuller, C. R.

    1976-01-01

    This paper proposes a process for inexpensive high performance solar cell fabrication that can be automated for further cost reduction and higher throughputs. The unique feature of the process is the use of oxides as doping sources for simultaneous n(+) junction formation and back p(+) layer, as a mask for metallization and as an in situ AR coating for spectrum matching. Cost analysis is performed to show that significant cost reductions over the conventional process is possible using the proposed scheme and the cost intensive steps are identified which can be further reduced to make the process compatible with the needed price goals of 50 cents/watt. The process was demonstrated by fabricating n(+)-p cells using Arsenic doped oxides. Simple n(+)-p structure cells showed corrected efficiencies of 14.5% (AMO) and 12% with doped oxide as an in situ antireflection coating.

  14. High performance, inexpensive solar cell process capable of a high degree of automation

    NASA Technical Reports Server (NTRS)

    Shah, P.; Fuller, C. R.

    1976-01-01

    This paper proposes a process for inexpensive high performance solar cell fabrication that can be automated for further cost reduction and higher throughputs. The unique feature of the process is the use of oxides as doping sources for simultaneous n(+) junction formation and back p(+) layer, as a mask for metallization and as an in situ AR coating for spectrum matching. Cost analysis is performed to show that significant cost reductions over the conventional process is possible using the proposed scheme and the cost intensive steps are identified which can be further reduced to make the process compatible with the needed price goals of 50 cents/watt. The process was demonstrated by fabricating n(+)-p cells using Arsenic doped oxides. Simple n(+)-p structure cells showed corrected efficiencies of 14.5% (AMO) and 12% with doped oxide as an in situ antireflection coating.

  15. High performance spiral wound microbial fuel cell with hydraulic characterization.

    PubMed

    Haeger, Alexander; Forrestal, Casey; Xu, Pei; Ren, Zhiyong Jason

    2014-12-01

    The understanding and development of functioning systems are crucial steps for microbial fuel cell (MFC) technology advancement. In this study, a compact spiral wound MFC (swMFC) was developed and hydraulic residence time distribution (RTD) tests were conducted to investigate the flow characteristics in the systems. Results show that two-chamber swMFCs have high surface area to volume ratios of 350-700m(2)/m(3), and by using oxygen cathode without metal-catalysts, the maximum power densities were 42W/m(3) based on total volume and 170W/m(3) based on effective volume. The hydraulic step-input tracer study identified 20-67% of anodic flow dead space, which presents new opportunities for system improvement. Electrochemical tools revealed very low ohmic resistance but high charge transfer and diffusion resistance due to catalyst-free oxygen reduction. The spiral wound configuration combined with RTD tool offers a holistic approach for MFC development and optimization.

  16. Recent Advances in High-Performance Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, S. R.; Chun, W.; Valdez, T. I.; Jeffries-Nakamura, B.; Frank, H.; Surumpudi, S.; Halpert, G.; Kosek, J.; Cropley, C.; La Conti, A. B.; hide

    1996-01-01

    Direct methanol fuel cells for portable power applications have been advanced significantly under DARPA- and ARO-sponsored programs over the last five years. A liquid-feed, direct methanol fuel cell developed under these programs, employs a proton exchange membrane as electrolyte and operates on aqueous solutions of methanol with air or oxygen as the oxidant.

  17. Effects of high doping levels silicon solar cell performance

    NASA Technical Reports Server (NTRS)

    Godlewski, M. P.; Brandhorst, H. W., Jr.; Baraona, C. R.

    1975-01-01

    The significance of the heavy doping effects (HDE) on the open-circuit voltage of silicon solar cells is assessed. Voltage calculations based on diffusion theory are modified to include the first order features of the HDE. Comparisions of the open-circuit voltage measured for cells of various base resistivities are made with those calculated using the diffusion model with and without the HDE. Results indicate that the observed variation of voltage with base resistivity is predicted by these effects. A maximum efficiency of 19% (AM0) and a voltage of 0.7 volts are calculated for 0.1 omega-cm cells assuming an optimum diffused layer impurity profile.

  18. High Performance InGaN-Based Solar Cells

    DTIC Science & Technology

    2012-05-12

    configuration by shorting together two terminals of the same polarity at the bonding interface. Finally, it will be necessary to have a dichroic...that there may be some advantages for semipolar or nonpolar solar cells due a reduction or elimination of the polarization -related electric fields in... polarization on carrier collection for solar cells with relatively low indium content active regions (e.g. xɘ.15 in InxGai.xN). Screening

  19. Highly conductive anion exchange membrane for high power density fuel-cell performance.

    PubMed

    Ren, Xiaoming; Price, Samuel C; Jackson, Aaron C; Pomerantz, Natalie; Beyer, Frederick L

    2014-08-27

    Anion exchange membrane fuel cells (AEMFCs) are regarded as a new generation of fuel cell technology that has the potential to overcome many obstacles of the mainstream proton exchange membrane fuel cells (PEMFCs) in cost, catalyst stability, efficiency, and system size. However, the low ionic conductivity and poor thermal stability of current anion exchange membranes (AEMs) have been the key factors limiting the performance of AEMFCs. In this study, an AEM made of styrenic diblock copolymer with a quaternary ammonium-functionalized hydrophilic block and a cross-linkable hydrophobic block and possessing bicontinuous phases of a hydrophobic network and hydrophilic conduction paths was found to have high ionic conductivity at 98 mS cm(-1) and controlled membrane swelling with water uptake at 117 wt % at 22 °C. Membrane characterizations and fuel cell tests of the new AEM were carried out together with a commercial AEM, Tokuyama A201, for comparison. The high ionic conductivity and water permeability of the new membrane reported in this study is attributed to the reduced torturosity of the ionic conduction paths, while the hydrophobic network maintains the membrane mechanical integrity, preventing excessive water uptake.

  20. Method to fabricate high performance tubular solid oxide fuel cells

    SciTech Connect

    Chen, Fanglin; Yang, Chenghao; Jin, Chao

    2013-06-18

    In accordance with the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes forming an asymmetric porous ceramic tube by using a phase inversion process. The method further includes forming an asymmetric porous ceramic layer on a surface of the asymmetric porous ceramic tube by using a phase inversion process. The tube is co-sintered to form a structure having a first porous layer, a second porous layer, and a dense layer positioned therebetween.

  1. High performance, high durability non-precious metal fuel cell catalysts

    DOEpatents

    Wood, Thomas E.; Atanasoski, Radoslav; Schmoeckel, Alison K.

    2016-03-15

    This invention relates to non-precious metal fuel cell cathode catalysts, fuel cells that contain these catalysts, and methods of making the same. The fuel cell cathode catalysts are highly nitrogenated carbon materials that can contain a transition metal. The highly nitrogenated carbon materials can be supported on a nanoparticle substrate.

  2. Performance Assessment of Baseline Cells for the High Efficiency Space Power Systems Project

    NASA Technical Reports Server (NTRS)

    Schneidegger, Brianne T.

    2012-01-01

    The Enabling Technology Development and Demonstration (ETDD) Program High Efficiency Space Power Systems (HESPS) Project, formerly the Exploration Technology Development Program (ETDP) Energy Storage Project is tasked with developing advanced lithium-ion cells for future NASA Exploration missions. Under this project, components under development via various in-house and contracted efforts are delivered to Saft America for scale-up and integration into cells. Progress toward meeting project goals will be measured by comparing the performance to these cells with cells of a similar format with Saft s state-of-the-art aerospace chemistry. This report discusses the results of testing performed on the first set of baseline cells delivered by Saft to the NASA Glenn Research Center. This build is a cylindrical "DD" geometry with a 10 Ah nameplate capacity. Testing is being performed to establish baseline cell performance at conditions relevant to ETDD HESPS Battery Key Performance Parameter (KPP) goals including various temperatures, rates, and cycle life conditions. Data obtained from these cells will serve as a performance baseline for future cell builds containing optimized ETDD HESPSdeveloped materials. A test plan for these cells was developed to measure cell performance against the high energy cell KPP goals. The goal for cell-level specific energy of the high energy technology is 180 Wh/kg at a C/10 discharge rate and 0 C. The cells should operate for at least 2000 cycles at 100 percent DOD with 80 percent capacity retention. Baseline DD cells delivered 152 Wh/kg at 20 C. This number decreased to 143.9 Wh/kg with a 0 C discharge. This report provides performance data and summarizes results of the testing performed on the DD cells.

  3. High electron mobility ZnO film for high-performance inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Lv, Peiwen; Chen, Shan-Ci; Zheng, Qingdong; Huang, Feng; Ding, Kai

    2015-04-01

    High-quality ZnO films (ZnO-MS) are prepared via magnetron sputtering deposition with a high mobility of about 2 cm2/(V.s) and are used as electron transport layer for inverted polymer solar cells (PSCs) with polymer poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene-co-3-fluorothieno[3,4-b]thiophene-2-carboxylate]:[6,6]-phenyl C71-butyric acid methyl ester as the active layer. A significant improvement of JSC, about 20% enhancement in contrast to the devices built on sol-gel derived ZnO film (ZnO-Sol), is found in the ZnO-MS based device. High performance ZnO-MS based PSCs exhibit power conversion efficiency (PCE) up to 8.55%, which is much better than the device based on ZnO-Sol (PCE = 7.78%). Further research on cathode materials is promising to achieve higher performance.

  4. High electron mobility ZnO film for high-performance inverted polymer solar cells

    SciTech Connect

    Lv, Peiwen; Chen, Shan-Ci; Zheng, Qingdong; Huang, Feng Ding, Kai

    2015-04-20

    High-quality ZnO films (ZnO-MS) are prepared via magnetron sputtering deposition with a high mobility of about 2 cm{sup 2}/(V·s) and are used as electron transport layer for inverted polymer solar cells (PSCs) with polymer poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′] dithiophene-co-3-fluorothieno[3,4-b]thiophene-2-carboxylate]:[6,6]-phenyl C71-butyric acid methyl ester as the active layer. A significant improvement of J{sub SC}, about 20% enhancement in contrast to the devices built on sol-gel derived ZnO film (ZnO-Sol), is found in the ZnO-MS based device. High performance ZnO-MS based PSCs exhibit power conversion efficiency (PCE) up to 8.55%, which is much better than the device based on ZnO-Sol (PCE = 7.78%). Further research on cathode materials is promising to achieve higher performance.

  5. Characterization of high performance silicon-based VMJ PV cells for laser power transmission applications

    NASA Astrophysics Data System (ADS)

    Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsien; Zahuranec, Terry

    2016-03-01

    Continuing improvements in the cost and power of laser diodes have been critical in launching the emerging fields of power over fiber (PoF), and laser power beaming. Laser power is transmitted either over fiber (for PoF), or through free space (power beaming), and is converted to electricity by photovoltaic cells designed to efficiently convert the laser light. MH GoPower's vertical multi-junction (VMJ) PV cell, designed for high intensity photovoltaic applications, is fueling the emergence of this market, by enabling unparalleled photovoltaic receiver flexibility in voltage, cell size, and power output. Our research examined the use of the VMJ PV cell for laser power transmission applications. We fully characterized the performance of the VMJ PV cell under various laser conditions, including multiple near IR wavelengths and light intensities up to tens of watts per cm2. Results indicated VMJ PV cell efficiency over 40% for 9xx nm wavelengths, at laser power densities near 30 W/cm2. We also investigated the impact of the physical dimensions (length, width, and height) of the VMJ PV cell on its performance, showing similarly high performance across a wide range of cell dimensions. We then evaluated the VMJ PV cell performance within the power over fiber application, examining the cell's effectiveness in receiver packages that deliver target voltage, intensity, and power levels. By designing and characterizing multiple receivers, we illustrated techniques for packaging the VMJ PV cell for achieving high performance (> 30%), high power (> 185 W), and target voltages for power over fiber applications.

  6. Relationship between the blue response and open-circuit voltage of high performance silicon solar cells

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    The relationship between the response at blue wavelengths and the open-circuit voltage of high performance silicon solar cells with a virtually 'transparent' emitter is analyzed. It is shown that a one-dimensional cell model cannot simultaneously model the optical collection properties and operating characteristics of such cells. The analysis highlights the importance of surface conditions and shows that previous conclusions regarding bounds on Auger coefficients imposed by correlating these parameters must be treated with caution.

  7. The Environmental Performance at Low Intensity, Low Temperature (LILT) of High Efficiency Triple Junction Solar Cells

    NASA Technical Reports Server (NTRS)

    Stella, Paul M.; Mueller, Robert; Davis, Gregory; Distefano, Salvador

    2004-01-01

    A number of JPL missions, either active or in the p l d g stages, require the accurate LILT flew intensity - low temperate) climate of triple-junction solar. Although triple ignition LILT performance was reported as recently as 2002, there has been an evolutionary advance in cell technology by both U.S. space cell manufacturers that, for mission design purposes, effectively obsoletes the earlier data. As a result, JPL initiated a program to develop a database for the LILT performance of the new high performance triple junction solar cells. JPL obtained Emcore Advanced triple Juntion CIC assemblies and Spectrolab Ultra Triple Junction CIC assemblies. These cells were tested at temperature-intensity ranges designed to cover applications between 1 and 5.18 AU solar distances. 1 MeV electron irradiation from 25 E14 to 1 El5 w were performed on the cells to evaluate the combined effect of particulate radiation and LILT conditions. The effect of LILT conditions was observed to incur an increase in the variation of cell performances such that at simulted 5.18 AU conditions the average performance was approximately 30% with the best cells measuring between 32 and 34% efficiency. The 30% average efficiency compares with approximately 25% average efficiency measured on earlier technology triple junction solar cells.

  8. The Environmental Performance at Low Intensity, Low Temperature (LILT) of High Efficiency Triple Junction Solar Cells

    NASA Technical Reports Server (NTRS)

    Stella, Paul M.; Mueller, Robert; Davis, Gregory; Distefano, Salvador

    2004-01-01

    A number of JPL missions, either active or in the p l d g stages, require the accurate LILT flew intensity - low temperate) climate of triple-junction solar. Although triple ignition LILT performance was reported as recently as 2002, there has been an evolutionary advance in cell technology by both U.S. space cell manufacturers that, for mission design purposes, effectively obsoletes the earlier data. As a result, JPL initiated a program to develop a database for the LILT performance of the new high performance triple junction solar cells. JPL obtained Emcore Advanced triple Juntion CIC assemblies and Spectrolab Ultra Triple Junction CIC assemblies. These cells were tested at temperature-intensity ranges designed to cover applications between 1 and 5.18 AU solar distances. 1 MeV electron irradiation from 25 E14 to 1 El5 w were performed on the cells to evaluate the combined effect of particulate radiation and LILT conditions. The effect of LILT conditions was observed to incur an increase in the variation of cell performances such that at simulted 5.18 AU conditions the average performance was approximately 30% with the best cells measuring between 32 and 34% efficiency. The 30% average efficiency compares with approximately 25% average efficiency measured on earlier technology triple junction solar cells.

  9. Performance enhancement of direct ethanol fuel cell using Nafion composites with high volume fraction of titania

    NASA Astrophysics Data System (ADS)

    Matos, B. R.; Isidoro, R. A.; Santiago, E. I.; Fonseca, F. C.

    2014-12-01

    The present study reports on the performance enhancement of direct ethanol fuel cell (DEFC) at 130 °C with Nafion-titania composite electrolytes prepared by sol-gel technique and containing high volume fractions of the ceramic phase. It is found that for high volume fractions of titania (>10 vol%) the ethanol uptake of composites is largely reduced while the proton conductivity at high-temperatures is weakly dependent on the titania content. Such tradeoff between alcohol uptake and conductivity resulted in a boost of DEFC performance at high temperatures using Nafion-titania composites with high fraction of the inorganic phase.

  10. Robust high-performance nanoliter-volume single-cell multiple displacement amplification on planar substrates

    PubMed Central

    Leung, Kaston; Klaus, Anders; Lin, Bill K.; Laks, Emma; Biele, Justina; Lai, Daniel; Bashashati, Ali; Huang, Yi-Fei; Aniba, Radhouane; Moksa, Michelle; Steif, Adi; Mes-Masson, Anne-Marie; Hirst, Martin; Shah, Sohrab P.; Aparicio, Samuel; Hansen, Carl L.

    2016-01-01

    The genomes of large numbers of single cells must be sequenced to further understanding of the biological significance of genomic heterogeneity in complex systems. Whole genome amplification (WGA) of single cells is generally the first step in such studies, but is prone to nonuniformity that can compromise genomic measurement accuracy. Despite recent advances, robust performance in high-throughput single-cell WGA remains elusive. Here, we introduce droplet multiple displacement amplification (MDA), a method that uses commercially available liquid dispensing to perform high-throughput single-cell MDA in nanoliter volumes. The performance of droplet MDA is characterized using a large dataset of 129 normal diploid cells, and is shown to exceed previously reported single-cell WGA methods in amplification uniformity, genome coverage, and/or robustness. We achieve up to 80% coverage of a single-cell genome at 5× sequencing depth, and demonstrate excellent single-nucleotide variant (SNV) detection using targeted sequencing of droplet MDA product to achieve a median allelic dropout of 15%, and using whole genome sequencing to achieve false and true positive rates of 9.66 × 10−6 and 68.8%, respectively, in a G1-phase cell. We further show that droplet MDA allows for the detection of copy number variants (CNVs) as small as 30 kb in single cells of an ovarian cancer cell line and as small as 9 Mb in two high-grade serous ovarian cancer samples using only 0.02× depth. Droplet MDA provides an accessible and scalable method for performing robust and accurate CNV and SNV measurements on large numbers of single cells. PMID:27412862

  11. Characterization of high-temperature performance of cesium vapor cells with anti-relaxation coating

    NASA Astrophysics Data System (ADS)

    Li, Wenhao; Balabas, Mikhail; Peng, Xiang; Pustelny, Szymon; Wickenbrock, Arne; Guo, Hong; Budker, Dmitry

    2017-02-01

    Vapor cells with antirelaxation coating are widely used in modern atomic physics experiments due to the coating's ability to maintain the atoms' spin polarization during wall collisions. We characterize the performance of vapor cells with different coating materials by measuring longitudinal spin relaxation and vapor density at temperatures up to 95 °C. We infer that the spin-projection-noise-limited sensitivity for atomic magnetometers with such cells improves with temperature, which demonstrates the potential of antirelaxation coated cells in applications of future high-sensitivity magnetometers.

  12. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    SciTech Connect

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.

  13. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    DOE PAGES

    Lu, Luyao; Chen, Wei; Xu, Tao; ...

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increasedmore » hole extraction, efficient energy transfer and better morphology. As a result, the working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.« less

  14. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    PubMed Central

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-01-01

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs. PMID:26041586

  15. High-performance silicon nanowire array photoelectrochemical solar cells through surface passivation and modification.

    PubMed

    Wang, Xin; Peng, Kui-Qing; Pan, Xiao-Jun; Chen, Xue; Yang, Yang; Li, Li; Meng, Xiang-Min; Zhang, Wen-Jun; Lee, Shuit-Tong

    2011-10-10

    Nanowire solar cells: Pt nanoparticle (PtNP) decorated C/Si core/shell nanowire photoelectrochemical solar cells show high conversion efficiency of 10.86 % and excellent stability in aggressive electrolytes under 1-sun AM 1.5 G illumination. Superior device performance is achieved by improved surface passivation of the nanowires by carbon coating and enhanced interfacial charge transfer by PtNPs.

  16. Application of mixed-organic-cation for high performance hole-conductor-free perovskite solar cells.

    PubMed

    Xiao, Meng; Zhao, Li; Wei, Shoubin; Li, Yanyan; Dong, Binghai; Xu, Zuxun; Wan, Li; Wang, Shimin

    2017-09-15

    ABX3-type organic lead halide perovskites have gained increasing attention as light harvester for solar cells due to their high power conversion efficiency (PCE). Recently, it has become a trend to avoid the use of expensive hole-transport materials (HTMs) and precious metals, such as Au, to be competitive in future commercial development. In this study, we fabricated mixed-cation perovskite-based solar cells through one-step spin-coating using methylammonium (CH3NH3(+)) and formamidinium (HN=CHNH3(+)) cations to extend the optical absorption range into the red region and enhance the utilization of solar light. The synthesized hole-conductor-free cells with carbon electrode and mixed cations exhibited increased short-circuit current, outperforming the cells prepared with pure methylammonium, and PCE of 10.55%. This paper proposes an efficient approach for fabricating high-performance and low-cost perovskite solar cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Optimization of molecular organization and nanoscale morphology for high performance low bandgap polymer solar cells

    NASA Astrophysics Data System (ADS)

    He, Ming; Wang, Mengye; Lin, Changjian; Lin, Zhiqun

    2014-03-01

    Rational design and synthesis of low bandgap (LBG) polymers with judiciously tailored HOMO and LUMO levels have emerged as a viable route to high performance polymer solar cells with power conversion efficiencies (PCEs) exceeding 10%. In addition to engineering the energy-level of LBG polymers, the photovoltaic performance of LBG polymer-based solar cells also relies on the device architecture, in particular the fine morphology of the photoactive layer. The nanoscale interpenetrating networks composed of nanostructured donor and acceptor phases are the key to providing a large donor-acceptor interfacial area for maximizing the exciton dissociation and offering a continuous pathway for charge transport. In this Review Article, we summarize recent strategies for tuning the molecular organization and nanoscale morphology toward an enhanced photovoltaic performance of LBG polymer-based solar cells.

  18. Optimization of molecular organization and nanoscale morphology for high performance low bandgap polymer solar cells.

    PubMed

    He, Ming; Wang, Mengye; Lin, Changjian; Lin, Zhiqun

    2014-04-21

    Rational design and synthesis of low bandgap (LBG) polymers with judiciously tailored HOMO and LUMO levels have emerged as a viable route to high performance polymer solar cells with power conversion efficiencies (PCEs) exceeding 10%. In addition to engineering the energy-level of LBG polymers, the photovoltaic performance of LBG polymer-based solar cells also relies on the device architecture, in particular the fine morphology of the photoactive layer. The nanoscale interpenetrating networks composed of nanostructured donor and acceptor phases are the key to providing a large donor-acceptor interfacial area for maximizing the exciton dissociation and offering a continuous pathway for charge transport. In this Review Article, we summarize recent strategies for tuning the molecular organization and nanoscale morphology toward an enhanced photovoltaic performance of LBG polymer-based solar cells.

  19. Carbon nanofibers modified graphite felt for high performance anode in high substrate concentration microbial fuel cells.

    PubMed

    Shen, Youliang; Zhou, Yan; Chen, Shuiliang; Yang, Fangfang; Zheng, Suqi; Hou, Haoqing

    2014-01-01

    Carbon nanofibers modified graphite fibers (CNFs/GF) composite electrode was prepared for anode in high substrate concentration microbial fuel cells. Electrochemical tests showed that the CNFs/GF anode generated a peak current density of 2.42 mA cm(-2) at a low acetate concentration of 20 mM, which was 54% higher than that from bare GF. Increase of the acetate concentration to 80 mM, in which the peak current density of the CNFs/GF anode greatly increased and was up to 3.57 mA cm(-2), was seven times as that of GF anode. Morphology characterization revealed that the biofilms in the CNFs/GF anode were much denser than those in the bare GF. This result revealed that the nanostructure in the anode not only enhanced current generation but also could tolerate high substrate concentration.

  20. Performance degradation of high-power lithium-ion cells-Electrochemistry of harvested electrodes

    NASA Astrophysics Data System (ADS)

    Abraham, D. P.; Knuth, J. L.; Dees, D. W.; Bloom, I.; Christophersen, J. P.

    The performance of 18650-type high-power lithium-ion cells is being evaluated as part of the U.S. Department of Energy's (DOEs) Advanced Technology Development (ATD) program. In this article, we present accelerated aging data acquired on 18650-cells containing LiNi 0.8Co 0.15Al 0.05O 2- or LiNi 0.8Co 0.1Al 0.1O 2-based positive electrodes, MAG-10 graphite-based negative electrodes, and 1.2-M LiPF 6 in EC:EMC (3:7 by wt.) electrolyte. Capacity and impedance data acquired on electrodes harvested from these cells highlight the contributions of the positive and negative electrodes to the degradation of cell performance. We also describe test methodologies used to examine the electrochemical characteristics of the harvested electrodes. Identifying and optimizing cell components responsible for performance degradation should enable the development of new lithium-ion cell chemistries that will meet the 15-year cell calendar life goal established by DOEs FreedomCar initiative.

  1. A low-cost, high-performance zinc-hydrogen peroxide fuel cell

    NASA Astrophysics Data System (ADS)

    An, L.; Zhao, T. S.; Zhou, X. L.; Yan, X. H.; Jung, C. Y.

    2015-02-01

    Electric vehicles (EVs) are primarily limited by the distance they can travel, charge time and cost. Here we report a catalyst-free, high-performance zinc-hydrogen peroxide fuel cell that consists of a redox flow cell with the respective redox couple at the anode (V(II)/V(III)) and cathode (V(IV)/V(V)) regenerated by the fuel (zinc) and the oxidant (hydrogen peroxide). Unlike batteries that have low capacities and need to be frequently charged, the present fuel cell enables future vehicles to travel farther distances on one charge and almost instantaneous charge time. More importantly, it is demonstrated that this novel fuel cell exhibits an extraordinarily high peak power density of 1192 mW cm-2 at 60 °C, a performance which is about five times higher than that of state-of-the-art conventional fuel cells of the kind (265 mW cm-2). Another striking feature of the present fuel cell is that it does not require catalysts, allowing the power pack to be both cost-effective and durable. These important features make the present fuel cell a promising post lithium-ion technology, opening a sustainable way to propel next-generation vehicles.

  2. Thermal evaluation and performance of high-power Lithium-ion cells

    SciTech Connect

    Keyser, M.; Pesaran, A.; Oweis, S.; Chagnon, G.; Ashtiani, C.

    2000-01-25

    Under the sponsorship of the US Advanced Battery Consortium (USABC) and the Partnership for a New Generation of Vehicles (PNGV), Saft has developed high-power lithium-ion (Li-Ion) batteries for hybrid electric vehicles (HEVs). These high-power Li-Ion batteries are being evaluated for the US Department of Energy's (DOE) Hybrid Vehicle Propulsion Program. As part of this program, the National Renewable Energy Laboratory (NREL) characterized the thermal performance of the Saft (6-Ah) Li-Ion cells. The characterization included (1) obtaining thermal images of cells under a specified cycle, (2) measuring heat generation from the cells at various temperatures and under various charge/discharge profiles, and (3) determining the cells' capabilities for following a simulated power profile (driving cycle) at various initial states of charge and temperatures.

  3. A switchable pH-differential unitized regenerative fuel cell with high performance

    NASA Astrophysics Data System (ADS)

    Lu, Xu; Xuan, Jin; Leung, Dennis Y. C.; Zou, Haiyang; Li, Jiantao; Wang, Hailiang; Wang, Huizhi

    2016-05-01

    Regenerative fuel cells are a potential candidate for future energy storage, but their applications are limited by the high cost and poor round-trip efficiency. Here we present a switchable pH-differential unitized regenerative fuel cell capable of addressing both the obstacles. Relying on a membraneless laminar flow-based design, pH environments in the cell are optimized independently for different electrode reactions and are switchable together with the cell process to ensure always favorable thermodynamics for each electrode reaction. Benefiting from the thermodynamic advantages of the switchable pH-differential arrangement, the cell allows water electrolysis at a voltage of 0.57 V, and a fuel cell open circuit voltage of 1.89 V, rendering round-trip efficiencies up to 74%. Under room conditions, operating the cell in fuel cell mode yields a power density of 1.3 W cm-2, which is the highest performance to date for laminar flow-based cells and is comparable to state-of-the-art polymer electrolyte membrane fuel cells.

  4. Coiling and maturation of a high-performance fibre in hagfish slime gland thread cells

    NASA Astrophysics Data System (ADS)

    Winegard, Timothy; Herr, Julia; Mena, Carlos; Lee, Betty; Dinov, Ivo; Bird, Deborah; Bernards, Mark; Hobel, Sam; van Valkenburgh, Blaire; Toga, Arthur; Fudge, Douglas

    2014-04-01

    The defensive slime of hagfishes contains thousands of intermediate filament protein threads that are manufactured within specialized gland thread cells. The material properties of these threads rival those of spider dragline silks, which makes them an ideal model for biomimetic efforts to produce sustainable protein materials, yet how the thread is produced and organized within the cell is not well understood. Here we show how changes in nuclear morphology, size and position can explain the three-dimensional pattern of thread coiling in gland thread cells, and how the ultrastructure of the thread changes as very young thread cells develop into large cells with fully mature coiled threads. Our model provides an explanation for the complex process of thread assembly and organization that has fascinated and perplexed biologists for over a century, and provides valuable insights for the quest to manufacture high-performance biomimetic protein materials.

  5. Coiling and maturation of a high-performance fibre in hagfish slime gland thread cells.

    PubMed

    Winegard, Timothy; Herr, Julia; Mena, Carlos; Lee, Betty; Dinov, Ivo; Bird, Deborah; Bernards, Mark; Hobel, Sam; Van Valkenburgh, Blaire; Toga, Arthur; Fudge, Douglas

    2014-04-04

    The defensive slime of hagfishes contains thousands of intermediate filament protein threads that are manufactured within specialized gland thread cells. The material properties of these threads rival those of spider dragline silks, which makes them an ideal model for biomimetic efforts to produce sustainable protein materials, yet how the thread is produced and organized within the cell is not well understood. Here we show how changes in nuclear morphology, size and position can explain the three-dimensional pattern of thread coiling in gland thread cells, and how the ultrastructure of the thread changes as very young thread cells develop into large cells with fully mature coiled threads. Our model provides an explanation for the complex process of thread assembly and organization that has fascinated and perplexed biologists for over a century, and provides valuable insights for the quest to manufacture high-performance biomimetic protein materials.

  6. High Performance Flexible Perovskite Solar Cells on Ultra-Thin Glass: implications of the TCO.

    PubMed

    Dou, Benjia; Miller, Elisa M; Christians, Jeffrey A; Sanehira, Erin M; Klein, Talysa; Barnes, Frank; Shaheen, Sean E; Garner, Sean; Ghosh, Shuvaraj; Mallick, Arindam; Basak, Durga; van Hest, Maikel F A M

    2017-09-25

    For halide perovskite solar cells (PSC) to fulfil their vast potential for combining low-cost, high efficiency, and high throughput production they must be scaled using a truly transformative method, such as roll-to-roll processing. Bringing this reality closer to fruition, the present work demonstrates flexible perovskite solar cells with 18.1% power conversion efficiency on flexible Willow Glass substrates. We highlight the importance of the transparent conductive oxide (TCO) layers on device performance by studying various TCOs. While tin-doped indium oxide and indium zinc oxide based PSC devices demonstrate high photovoltaic performances, aluminum-doped zinc oxide (AZO) based devices underperformed in all device parameters. Analysis of x-ray photoemission spectroscopy data shows that the stoichiometry of the perovskite film surface changes dramatically when it is fabricated on AZO, demonstrating the importance of the substrate in perovskite film formation.

  7. Final Technical Report, Oct 2004 - Nov. 2006, High Performance Flexible Reversible Solid Oxide Fuel Cell

    SciTech Connect

    Guan, Jie; Minh, Nguyen

    2007-02-21

    This report summarizes the work performed for the program entitled “High Performance Flexible Reversible Solid Oxide Fuel Cell” under Cooperative Agreement DE-FC36-04GO14351 for the U. S. Department of Energy. The overall objective of this project is to demonstrate a single modular stack that generates electricity from a variety of fuels (hydrogen and other fuels such as biomass, distributed natural gas, etc.) and when operated in the reverse mode, produces hydrogen from steam. This project has evaluated and selected baseline cell materials, developed a set of materials for oxygen and hydrogen electrodes, and optimized electrode microstructures for reversible solid oxide fuel cells (RSOFCs); and demonstrated the feasibility and operation of a RSOFC multi-cell stack. A 10-cell reversible SOFC stack was operated over 1000 hours alternating between fuel cell (with hydrogen and methane as fuel) and steam electrolysis modes. The stack ran very successfully with high power density of 480 mW/cm2 at 0.7V and 80% fuel utilization in fuel cell mode and >6 SLPM hydrogen production in steam electrolysis mode using about 1.1 kW electrical power. The hydrogen generation is equivalent to a specific capability of 2.59 Nm3/m2 with electrical energy demand of 3 kWh/Nm3. The performance stability in electrolysis mode was improved vastly during the program with a degradation rate reduction from 8000 to 200 mohm-cm2/1000 hrs. This was accomplished by increasing the activity and improving microstructure of the oxygen electrode. Both cost estimate and technology assessment were conducted. Besides the flexibility running under both fuel cell mode and electrolysis mode, the reversible SOFC system has the potentials for low cost and high efficient hydrogen production through steam electrolysis. The cost for hydrogen production at large scale was estimated at ~$2.7/kg H2, comparing favorably with other electrolysis techology.

  8. High Performance Ultrathin GaAs Solar Cells Enabled with Heterogeneously Integrated Dielectric Periodic Nanostructures.

    PubMed

    Lee, Sung-Min; Kwong, Anthony; Jung, Daehwan; Faucher, Joseph; Biswas, Roshni; Shen, Lang; Kang, Dongseok; Lee, Minjoo Larry; Yoon, Jongseung

    2015-10-27

    Due to their favorable materials properties including direct bandgap and high electron mobilities, epitaxially grown III-V compound semiconductors such as gallium arsenide (GaAs) provide unmatched performance over silicon in solar energy harvesting. Nonetheless, their large-scale deployment in terrestrial photovoltaics remains challenging mainly due to the high cost of growing device quality epitaxial materials. In this regard, reducing the thickness of constituent active materials under appropriate light management schemes is a conceptually viable option to lower the cost of GaAs solar cells. Here, we present a type of high efficiency, ultrathin GaAs solar cell that incorporates bifacial photon management enabled by techniques of transfer printing to maximize the absorption and photovoltaic performance without compromising the optimized electronic configuration of planar devices. Nanoimprint lithography and dry etching of titanium dioxide (TiO2) deposited directly on the window layer of GaAs solar cells formed hexagonal arrays of nanoscale posts that serve as lossless photonic nanostructures for antireflection, diffraction, and light trapping in conjunction with a co-integrated rear-surface reflector. Systematic studies on optical and electrical properties and photovoltaic performance in experiments, as well as numerical modeling, quantitatively describe the optimal design rules for ultrathin, nanostructured GaAs solar cells and their integrated modules.

  9. Solvent-Assisted Preparation of High-Performance Mesoporous CH₃NH₃Pbl₃ Perovskite Solar Cells.

    PubMed

    Li, Zhi-Hua; Liu, Jie; Ma, Jing-Yuan; Jiang, Yan; Ge, Qian-Qing; Ding, Jie; Hu, Jin-Song; Wan, Li-Jun

    2016-01-01

    Organometal trihalide perovskite based solar cells have attracted great attention worldwide since their power conversion efficiency (PCE) have risen to over 15% within only 3 years of development. Comparing with other types of perovskite solar cells, mesostructured perovskite solar cells based on CH₃NH₃Pbl₃ as light harvesting material have already demonstrated remarkable advance in performance and reproducibility. Here, we reported a mesoscopic TiO₂/CH₃NH₃Pbl₃ heterojunction solar cell with uniform perovskite thin film prepared via solvent-assisted solution processing method. The best performing device delivered photocurrent density of 20.11 mA cm⁻², open-circuit voltage of 1.02 V, and fill factor of 0.70, leading to a PCE of 14.41%. A small anomalous hysteresis in the J-V curves was observed, where the PCE at forward scan was measured to be 84% of the PCE at reverse scan. Based on a statistical analysis, the perovskite solar cells prepared by the reported method exhibited reproducible and high PCE, indicating its promising application in the fabrication of low-cost and high-efficiency perovskite solar cells.

  10. Achieving high performance polymer tandem solar cells via novel materials design

    NASA Astrophysics Data System (ADS)

    Dou, Letian

    Organic photovoltaic (OPV) devices show great promise in low-cost, flexible, lightweight, and large-area energy-generation applications. Nonetheless, most of the materials designed today always suffer from the inherent disadvantage of not having a broad absorption range, and relatively low mobility, which limit the utilization of the full solar spectrum. Tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation by combining two or more solar cells with different absorption bands. However, for polymer solar cells, the performance of tandem devices lags behind single-layer solar cells mainly due to the lack of suitable low-bandgap polymers (near-IR absorbing polymers). In this dissertation, in order to achieve high performance, we focus on design and synthesis of novel low bandgap polymers specifically for tandem solar cells. In Chapter 3, I demonstrate highly efficient single junction and tandem polymer solar cells featuring a spectrally matched low-bandgap conjugated polymer (PBDTT-DPP: bandgap, ˜1.44 eV). The polymer has a backbone based on alternating benzodithiophene and diketopyrrolopyrrole units. A single-layer device based on the polymer provides a power conversion efficiency of ˜6%. When the polymer is applied to tandem solar cells, a power conversion efficiency of 8.62% is achieved, which was the highest certified efficiency for a polymer solar cell. To further improve this material system, in Chapter 4, I show that the reduction of the bandgap and the enhancement of the charge transport properties of the low bandgap polymer PBDTT-DPP can be accomplished simultaneously by substituting the sulfur atoms on the DPP unit with selenium atoms. The newly designed polymer PBDTT-SeDPP (Eg = 1.38 eV) shows excellent photovoltaic performance in single junction devices with PCEs over 7% and photo-response up to 900 nm. Tandem polymer solar cells based on PBDTT-SeDPP are also demonstrated with a 9.5% PCE, which are more than 10

  11. Coiling and maturation of a high performance fibre in hagfish slime gland thread cells

    PubMed Central

    Winegard, Timothy; Herr, Julia; Mena, Carlos; Lee, Betty; Dinov, Ivo; Bird, Deborah; Bernards, Mark; Hobel, Sam; Van Valkenburgh, Blaire; Toga, Arthur; Fudge, Douglas

    2015-01-01

    Summary The defensive slime of hagfishes contains thousands of intermediate filament protein threads1 that are manufactured within specialized gland thread cells2–4. The outstanding material properties of these threads, which rival spider dragline silks, make them an ideal model for biomimetic efforts to produce sustainable protein materials5. The gland thread cell is remarkable because of the strength of the thread it produces, but also because of the thread’s impressive length (~150 mm)1, its exquisite packaging within the cytoplasm3,4, and its ability to deploy rapidly in seawater without tangling6. The thread bundle (or “skein”) is organized into staggered loops that spiral around the long axis of the cell. In mature cells, these highly organized loops fill most of the cell volume. Although the exact site of thread assembly is unknown, the thinnest regions of the thread are found adjacent to the nucleus7,8. Intermediate filaments and microtubules are known to interact during early stages of thread assembly, but the mature thread is electron dense with no discernable ultrastructure7,8. Until now, we have lacked information about gland thread cell development, including high power images of very young cells that could provide insight into how the thread is coiled and how it matures. Here we show (1) how changes in nuclear morphology, size, and position can explain the three-dimensional pattern of thread coiling in gland thread cells, and (2) how the ultrastructure of the thread changes from very young thread cells up to large cells with fully mature skeins7–9. Our model provides an explanation for the complex process of thread assembly and organization that has fascinated and perplexed biologists for over a century10, and provides valuable insights for the quest to manufacture high-performance biomimetic protein materials. PMID:24698953

  12. Development of high-performance Na/NiCl2 cell

    NASA Astrophysics Data System (ADS)

    Redey, L.; Vissers, D. R.; Myles, K. M.; Prakash, J.

    The performance of the Ni/NiCl2 positive electrode for the Na/NiCl2 battery has been significantly improved by lowering the impedance and increasing the usable capacity through the use of chemical additives and a tailored electrode morphology. The improved electrode has excellent performance even below 200 C and can be recharged within one hour. The performance of this new electrode was measured by a conventional galvanostatic method and by a newly developed 'powerdynamic' method. These measurements were used to project the performance of 40 to 60-kWh batteries built with this new electrode combined with already highly developed sodium/beta-alumina negative electrode. These calculated results yielded a specific power of 150-400 W/kg and a specific energy of 110-200 Wh/kg for batteries with single-tube and bipolar cell designs. This high performance, along with the high cell voltage, mid-temperature operation, fast recharge capability, and short-circuited failure mode of the electrode couple, makes the Na/NiCl2 battery attractive for electric vehicle applications.

  13. Efficient electricity production and simultaneously wastewater treatment via a high-performance photocatalytic fuel cell.

    PubMed

    Liu, Yanbiao; Li, Jinhua; Zhou, Baoxue; Li, Xuejin; Chen, Hongchong; Chen, Quanpeng; Wang, Zhongsheng; Li, Lei; Wang, Jiulin; Cai, Weimin

    2011-07-01

    A great quantity of wastewater were discharged into water body, causing serious environmental pollution. Meanwhile, the organic compounds in wastewater are important sources of energy. In this work, a high-performance short TiO(2) nanotube array (STNA) electrode was applied as photoanode material in a novel photocatalytic fuel cell (PFC) system for electricity production and simultaneously wastewater treatment. The results of current work demonstrate that various model compounds as well as real wastewater samples can be used as substrates for the PFC system. As a representative of model compounds, the acetic acid solution produces the highest cell performance with short-circuit current density 1.42 mA cm(-2), open-circuit voltage 1.48 V and maximum power density output 0.67 mW cm(-2). The STNA photoanode reveals obviously enhanced cell performance compared with TiO(2) nanoparticulate film electrode or other long nanotubes electrode. Moreover, the photoanode material, electrolyte concentration, pH of the initial solution, and cathode material were found to be important factors influencing the system performance of PFC. Therefore, the proposed fuel cell system provides a novel way of energy conversion and effective disposal mode of organics and serves well as a promising technology for wastewater treatment.

  14. High performance all polymer solar cells fabricated via non-halogenated solvents (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Zhou, Yan; Bao, Zhenan

    2015-10-01

    The performance of organic solar cells consisting of a donor/acceptor bulk heterojunction (BHJ) has rapidly improved over the past few years.1. Major efforts have been focused on developing a variety of donor materials to gain access to different regions of the solar spectrum as well as to improve carrier transport properties.2 On the other hand, the most utilized acceptors are still restricted to the fullerene family, which includes PC61BM, PC71BM and ICBA.2b, 3 All-polymer solar cells, consisting of polymers for both the donor and acceptor, gained significantly increased interests recently, because of their ease of solution processing, potentially low cost, versatility in molecular design, and their potential for good chemical and morphological stability due to entanglement of polymers. Unlike small molecular fullerene acceptors, polymer acceptors can benefit from the high mobility of intra-chain charge transport and exciton generation by both donor and acceptor. Despite extensive efforts on all-polymer solar cells in the past decade, the fundamental understanding of all-polymer solar cells is still in its inceptive stage regarding both the materials chemistry and structure physics.4 Thus, rational design rules must be utilized to enable fundamental materials understanding of the all polymer solar cells. We report high performance all-polymer solar cells employing polymeric donors based on isoindigo and acceptor based on perylenedicarboximide. The phase separation domain length scale correlates well with the JSC and is found to be highly sensitive to the aromatic co-monomer structures used in the crystalline donor polymers. With the PS polymer side chain engineering, the phase separation domain length scale decreased by more than 45%. The PCE and JSC of the devices increased accordingly by more than 20%. A JSC as high as 10.0 mA cm-2 is obtained with the donor-acceptor pair despite of a low LUMO-LUMO energy offset of less than 0.1 eV. All the factors such as

  15. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells

    NASA Astrophysics Data System (ADS)

    Bae, Kiho; Jang, Dong Young; Choi, Hyung Jong; Kim, Donghwan; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won; Shim, Joon Hyung

    2017-02-01

    In reducing the high operating temperatures (>=800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (<=600 °C). Among many protonic ceramics, yttrium-doped barium zirconate has attracted attention due to its excellent chemical stability, which is the main issue in protonic-ceramic fuel cells. However, poor sinterability of yttrium-doped barium zirconate discourages its fabrication as a thin-film electrolyte and integration on porous anode supports, both of which are essential to achieve high performance. Here we fabricate a protonic-ceramic fuel cell using a thin-film-deposited yttrium-doped barium zirconate electrolyte with no impeding grain boundaries owing to the columnar structure tightly integrated with nanogranular cathode and nanoporous anode supports, which to the best of our knowledge exhibits a record high-power output of up to an order of magnitude higher than those of other reported barium zirconate-based fuel cells.

  16. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells.

    PubMed

    Bae, Kiho; Jang, Dong Young; Choi, Hyung Jong; Kim, Donghwan; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won; Shim, Joon Hyung

    2017-02-23

    In reducing the high operating temperatures (≥800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (≤600 °C). Among many protonic ceramics, yttrium-doped barium zirconate has attracted attention due to its excellent chemical stability, which is the main issue in protonic-ceramic fuel cells. However, poor sinterability of yttrium-doped barium zirconate discourages its fabrication as a thin-film electrolyte and integration on porous anode supports, both of which are essential to achieve high performance. Here we fabricate a protonic-ceramic fuel cell using a thin-film-deposited yttrium-doped barium zirconate electrolyte with no impeding grain boundaries owing to the columnar structure tightly integrated with nanogranular cathode and nanoporous anode supports, which to the best of our knowledge exhibits a record high-power output of up to an order of magnitude higher than those of other reported barium zirconate-based fuel cells.

  17. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells

    PubMed Central

    Bae, Kiho; Jang, Dong Young; Choi, Hyung Jong; Kim, Donghwan; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won; Shim, Joon Hyung

    2017-01-01

    In reducing the high operating temperatures (≥800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (≤600 °C). Among many protonic ceramics, yttrium-doped barium zirconate has attracted attention due to its excellent chemical stability, which is the main issue in protonic-ceramic fuel cells. However, poor sinterability of yttrium-doped barium zirconate discourages its fabrication as a thin-film electrolyte and integration on porous anode supports, both of which are essential to achieve high performance. Here we fabricate a protonic-ceramic fuel cell using a thin-film-deposited yttrium-doped barium zirconate electrolyte with no impeding grain boundaries owing to the columnar structure tightly integrated with nanogranular cathode and nanoporous anode supports, which to the best of our knowledge exhibits a record high-power output of up to an order of magnitude higher than those of other reported barium zirconate-based fuel cells. PMID:28230080

  18. Systems and methods for advanced ultra-high-performance InP solar cells

    DOEpatents

    Wanlass, Mark

    2017-03-07

    Systems and Methods for Advanced Ultra-High-Performance InP Solar Cells are provided. In one embodiment, an InP photovoltaic device comprises: a p-n junction absorber layer comprising at least one InP layer; a front surface confinement layer; and a back surface confinement layer; wherein either the front surface confinement layer or the back surface confinement layer forms part of a High-Low (HL) doping architecture; and wherein either the front surface confinement layer or the back surface confinement layer forms part of a heterointerface system architecture.

  19. Cooperative tin oxide fullerene electron selective layers for high-performance planar perovskite solar cells

    SciTech Connect

    Ke, Weijun; Zhao, Dewei; Xiao, Chuanxiao; Wang, Changlei; Cimaroli, Alexander J.; Grice, Corey R.; Yang, Mengjin; Li, Zhen; Jiang, Chun -Sheng; Al-Jassim, Mowafak; Zhu, Kai; Kanatzidis, Mercouri G.; Fang, Guojia; Yan, Yanfa

    2016-08-17

    Both tin oxide (SnO2) and fullerenes have been reported as electron selective layers (ESLs) for producing efficient lead halide perovskite solar cells. Here, we report that SnO2 and fullerenes can work cooperatively to further boost the performance of perovskite solar cells. We find that fullerenes can be redissolved during perovskite deposition, allowing ultra-thin fullerenes to be retained at the interface and some dissolved fullerenes infiltrate into perovskite grain boundaries. The SnO2 layer blocks holes effectively; whereas, the fullerenes promote electron transfer and passivate both the SnO2/perovskite interface and perovskite grain boundaries. With careful device optimization, the best-performing planar perovskite solar cell using a fullerene passivated SnO2 ESL has achieved a steady-state efficiency of 17.75% and a power conversion efficiency of 19.12% with an open circuit voltage of 1.12 V, a short-circuit current density of 22.61 mA cm-2, and a fill factor of 75.8% when measured under reverse voltage scanning. In conclusion, we find that the partial dissolving of fullerenes during perovskite deposition is the key for fabricating high-performance perovskite solar cells based on metal oxide/fullerene ESLs.

  20. Cooperative tin oxide fullerene electron selective layers for high-performance planar perovskite solar cells

    SciTech Connect

    Ke, Weijun; Zhao, Dewei; Xiao, Chuanxiao; Wang, Changlei; Cimaroli, Alexander J.; Grice, Corey R.; Yang, Mengjin; Li, Zhen; Jiang, Chun-Sheng; Al-Jassim, Mowafak; Zhu, Kai; Kanatzidis, Mercouri G.; Fang, Guojia; Yan, Yanfa

    2016-01-01

    Both tin oxide (SnO2) and fullerenes have been reported as electron selective layers (ESLs) for producing efficient lead halide perovskite solar cells. Here, we report that SnO2 and fullerenes can work cooperatively to further boost the performance of perovskite solar cells. We find that fullerenes can be redissolved during perovskite deposition, allowing ultra-thin fullerenes to be retained at the interface and some dissolved fullerenes infiltrate into perovskite grain boundaries. The SnO2 layer blocks holes effectively; whereas, the fullerenes promote electron transfer and passivate both the SnO2/perovskite interface and perovskite grain boundaries. With careful device optimization, the best-performing planar perovskite solar cell using a fullerene passivated SnO2 ESL has achieved a steady-state efficiency of 17.75% and a power conversion efficiency of 19.12% with an open circuit voltage of 1.12 V, a short-circuit current density of 22.61 mA cm-2, and a fill factor of 75.8% when measured under reverse voltage scanning. We find that the partial dissolving of fullerenes during perovskite deposition is the key for fabricating high-performance perovskite solar cells based on metal oxide/fullerene ESLs.

  1. Cooperative tin oxide fullerene electron selective layers for high-performance planar perovskite solar cells

    DOE PAGES

    Ke, Weijun; Zhao, Dewei; Xiao, Chuanxiao; ...

    2016-08-17

    Both tin oxide (SnO2) and fullerenes have been reported as electron selective layers (ESLs) for producing efficient lead halide perovskite solar cells. Here, we report that SnO2 and fullerenes can work cooperatively to further boost the performance of perovskite solar cells. We find that fullerenes can be redissolved during perovskite deposition, allowing ultra-thin fullerenes to be retained at the interface and some dissolved fullerenes infiltrate into perovskite grain boundaries. The SnO2 layer blocks holes effectively; whereas, the fullerenes promote electron transfer and passivate both the SnO2/perovskite interface and perovskite grain boundaries. With careful device optimization, the best-performing planar perovskite solarmore » cell using a fullerene passivated SnO2 ESL has achieved a steady-state efficiency of 17.75% and a power conversion efficiency of 19.12% with an open circuit voltage of 1.12 V, a short-circuit current density of 22.61 mA cm-2, and a fill factor of 75.8% when measured under reverse voltage scanning. In conclusion, we find that the partial dissolving of fullerenes during perovskite deposition is the key for fabricating high-performance perovskite solar cells based on metal oxide/fullerene ESLs.« less

  2. Metal based gas diffusion layers for enhanced fuel cell performance at high current densities

    NASA Astrophysics Data System (ADS)

    Hussain, Nabeel; Van Steen, Eric; Tanaka, Shiro; Levecque, Pieter

    2017-01-01

    The gas diffusion layer strongly influences the performance and durability of polymer electrolyte fuel cells. A major drawback of current carbon fiber based GDLs is the non-controlled variation in porosity resulting in a random micro-structure. Moreover, when subjected to compression these materials show significant reduction in porosity and permeability leading to water management problems and mass transfer losses within the fuel cell. This study investigated the use of uniform perforated metal sheets as GDLs in conjunction with microchannel flowfields. A metal sheet design with a pitch of 110 μm and a hole diameter of 60 μm in combination with an MPL showed superior performance in the high current density region compared to a commercially available carbon paper based GDL in a single cell environment. Fuel cell testing with different oxidants (air, heliox and oxygen) indicate that the metal sheet offers both superior diffusion and reduced flooding in comparison to the carbon based GDL. The presence of the MPL has been found to be critical to the functionality of the metal sheet suggesting that the MPL design may represent an important optimisation parameter for further improvements in performance.

  3. Three-Dimensional BC/PEDOT Composite Nanofibers with High Performance for Electrode-Cell Interface.

    PubMed

    Chen, Chuntao; Zhang, Ting; Zhang, Qi; Feng, Zhangqi; Zhu, Chunlin; Yu, Yalin; Li, Kangming; Zhao, Mengyao; Yang, Jiazhi; Liu, Jian; Sun, Dongping

    2015-12-30

    There is an increasing need to synthesize biocompatible nanofibers with excellent mechanical and electrical performance for electrochemical and biomedical applications. Here we report a facile approach to prepare electroactive and flexible 3D nanostructured biomaterials with high performance based on bacterial cellulose (BC) nanofibers. Our approach can coat BC nanofibers with poly(3,4-ethylenedioxythiophene) (PEDOT) by in situ interfacial polymerization in a controllable manner. The PEDOT coating thickness is adjustable by the monomer concentration or reaction time during polymerization, producing nanofibers with a total diameter ranging from 30 to 200 nm. This fabrication process also provides a convenient method to tune different parameters such as the average pore size and electrical conductivity on the demands of actual applications. Our experiments have demonstrated that the 3D BC/PEDOT nanofibers exhibit high specific surface area, excellent mechanical properties, electroactive stability, and low cell cytotoxicity. With electrical stimulation, calcium imaging of PC12 neural cells on BC/PEDOT nanofibers has revealed a significant increase in the percentage of cells with higher action potentials, suggesting an enhanced capacitance effect of charge injection. As an attractive solution to the challenge of designing better electrode-cell interfaces, 3D BC/PEDOT nanofibers promise many important applications such as biosensing devices, smart drug delivery systems, and implantable electrodes for tissue engineering.

  4. A high performance intermediate temperature fuel cell based on a thick oxide-carbonate electrolyte

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Lan, Rong; Xu, Xiaoxiang; Tao, Shanwen; Jiang, Yinzhu; Kraft, Arno

    A high performance intermediate temperature fuel cell (ITFC) with composite electrolyte composed of co-doped ceria Ce 0.8Gd 0.05Y 0.15O 1.9 (GYDC) and a binary carbonate-based (52 mol% Li 2CO 3/48 mol% Na 2CO 3), 1.2 mm thick electrolyte layer has been developed. Co-doped Ce 0.8Gd 0.05Y 0.15O 1.9 was synthesized by a glycine-nitrate process and used as solid support matrix for the composite electrolyte. The conductivity of both composite electrolyte and GYDC supporting substrate were measured by AC impedance spectroscopy. It showed a sharp conductivity jump at about 500 °C when the carbonates melted. Single cells with thick electrolyte layer were fabricated by a dry-pressing technique using NiO as anode and Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ or lithiated NiO as cathode. The cell was tested at 450-550 °C using hydrogen as the fuel and air as the oxidant. Excellent performance with high power density of 670 mW cm -2 at 550 °C was achieved for a 1.2 mm thick composite electrolyte containing 40 wt% carbonates which is much higher than that of a cell based on pure GYDC with a 70 μm thick electrolyte layer.

  5. Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

    PubMed

    Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

    2014-10-28

    Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

  6. Unraveling the High Open Circuit Voltage and High Performance of Integrated Perovskite/Organic Bulk-Heterojunction Solar Cells.

    PubMed

    Dong, Shiqi; Liu, Yongsheng; Hong, Ziruo; Yao, Enping; Sun, Pengyu; Meng, Lei; Lin, Yuze; Huang, Jinsong; Li, Gang; Yang, Yang

    2017-08-09

    We have demonstrated high-performance integrated perovskite/bulk-heterojunction (BHJ) solar cells due to the low carrier recombination velocity, high open circuit voltage (VOC), and increased light absorption ability in near-infrared (NIR) region of integrated devices. In particular, we find that the VOC of the integrated devices is dominated by (or pinned to) the perovskite cells, not the organic photovoltaic cells. A Quasi-Fermi Level Pinning Model was proposed to understand the working mechanism and the origin of the VOC of the integrated perovskite/BHJ solar cell, which following that of the perovskite solar cell and is much higher than that of the low bandgap polymer based organic BHJ solar cell. Evidence for the model was enhanced by examining the charge carrier behavior and photovoltaic behavior of the integrated devices under illumination of monochromatic light-emitting diodes at different characteristic wavelength. This finding shall pave an interesting possibility for integrated photovoltaic devices to harvest low energy photons in NIR region and further improve the current density without sacrificing VOC, thus providing new opportunities and significant implications for future industry applications of this kind of integrated solar cells.

  7. A high-performance Raman-Ramsey Cs vapor cell atomic clock

    NASA Astrophysics Data System (ADS)

    Abdel Hafiz, Moustafa; Coget, Grégoire; Yun, Peter; Guérandel, Stéphane; de Clercq, Emeric; Boudot, Rodolphe

    2017-03-01

    We demonstrate a high-performance coherent-population-trapping (CPT) Cs vapor cell atomic clock using the push-pull optical pumping technique in the pulsed regime, allowing the detection of high-contrast and narrow Ramsey-CPT fringes. The impact of several experimental parameters onto the clock resonance and short-term fractional frequency stability, including the laser power, the cell temperature, and the Ramsey sequence parameters, has been investigated. We observe and explain the existence of a slight dependence on laser power of the central Ramsey-CPT fringe line-width in the pulsed regime. We report also that the central fringe line-width is commonly narrower than the expected Ramsey line-width given by 1 / ( 2 T R ) , with TR the free-evolution time, for short values of TR. The clock demonstrates a short-term fractional frequency stability at the level of 2.3 × 10 - 13 τ - 1 / 2 up to 100 s averaging time, mainly limited by the laser amplitude modulation noise. Comparable performances are obtained in the conventional continuous wave regime, with the use of an additional laser power stabilization setup. The pulsed interaction allows to reduce significantly the clock frequency sensitivity to laser power variations, especially for high values of TR. This pulsed CPT clock, ranking among the best microwave vapor cell atomic frequency standards, could find applications in telecommunication, instrumentation, defense or satellite-based navigation systems.

  8. Epitaxial 1D electron transport layers for high-performance perovskite solar cells.

    PubMed

    Han, Gill Sang; Chung, Hyun Suk; Kim, Dong Hoe; Kim, Byeong Jo; Lee, Jin-Wook; Park, Nam-Gyu; Cho, In Sun; Lee, Jung-Kun; Lee, Sangwook; Jung, Hyun Suk

    2015-10-07

    We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport.

  9. Tunable High Performance Cross-Linked Alkaline Anion Exchange Membranes for Fuel Cell Applications

    SciTech Connect

    Robertson, Nicholas J.; Kostalik, IV, Henry A.; Clark, Timothy J.; Mutolo, Paul F.; Abruña, Héctor D.; Coates, Geoffrey W.

    2010-02-23

    Fuel cells are energy conversion devices that show great potential in numerous applications ranging from automobiles to portable electronics. However, further development of fuel cell components is necessary for them to become commercially viable. One component critical to their performance is the polymer electrolyte membrane, which is an ion conductive medium separating the two electrodes. While proton conducting membranes are well established (e.g., Nafion), hydroxide conducting membranes (alkaline anion exchange membranes, AAEMs) have been relatively unexplored by comparison. Operating under alkaline conditions offers significant efficiency benefits, especially for the oxygen reduction reaction; therefore, effective AAEMs could significantly advance fuel cell technologies. Here we demonstrate the use of ring-opening metathesis polymerization to generate new cross-linked membrane materials exhibiting high hydroxide ion conductivity and good mechanical properties. Cross-linking allows for increased ion incorporation, which, in turn supports high conductivities. This facile synthetic approach enables the preparation of cross-linked materials with the potential to meet the demands of hydrogen-powered fuel cells as well as direct methanol fuel cells.

  10. Tunable high performance cross-linked alkaline anion exchange membranes for fuel cell applications.

    PubMed

    Robertson, Nicholas J; Kostalik, Henry A; Clark, Timothy J; Mutolo, Paul F; Abruña, Héctor D; Coates, Geoffrey W

    2010-03-17

    Fuel cells are energy conversion devices that show great potential in numerous applications ranging from automobiles to portable electronics. However, further development of fuel cell components is necessary for them to become commercially viable. One component critical to their performance is the polymer electrolyte membrane, which is an ion conductive medium separating the two electrodes. While proton conducting membranes are well established (e.g., Nafion), hydroxide conducting membranes (alkaline anion exchange membranes, AAEMs) have been relatively unexplored by comparison. Operating under alkaline conditions offers significant efficiency benefits, especially for the oxygen reduction reaction; therefore, effective AAEMs could significantly advance fuel cell technologies. Here we demonstrate the use of ring-opening metathesis polymerization to generate new cross-linked membrane materials exhibiting high hydroxide ion conductivity and good mechanical properties. Cross-linking allows for increased ion incorporation, which, in turn supports high conductivities. This facile synthetic approach enables the preparation of cross-linked materials with the potential to meet the demands of hydrogen-powered fuel cells as well as direct methanol fuel cells.

  11. Applications of ion implantation to high performance, radiation tolerant silicon solar cells

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, A. R.; Minnucci, J. A.; Matthei, K. W.

    1979-01-01

    Progress in the development of ion implanted silicon solar cells is reported. Effective back surface preparation by implantation, junction processing to achieve high open circuit voltages in low-resistivity cells, and radiation tolerance cells are among the topics studied.

  12. Control of geometrical properties of carbon nanotube electrodes towards high-performance microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Erbay, Celal; Pu, Xiong; Choi, Woongchul; Choi, Mi-Jin; Ryu, Yeontack; Hou, Huijie; Lin, Furong; de Figueiredo, Paul; Yu, Choongho; Han, Arum

    2015-04-01

    In microbial fuel cells (MFCs), physical and electrochemical interactions between microbes and electrode surfaces are critical to performance. Nanomaterial-based electrodes have shown promising performances, however their unique characteristics have not been fully utilized. The developed electrodes here consist of multi-wall carbon nanotubes (MWCNTs) directly grown in the radial direction from the wires of stainless steel (SS) meshes, providing extremely large three-dimensional surfaces while ensuring minimal ohmic loss between CNTs and SS meshes, fully utilizing the advantages of CNTs. Systematic studies on how different lengths, packing densities, and surface conditions of CNTs affect MFC power output revealed that long and loosely packed CNTs without any amorphous carbon show the highest power production performance. The power density of this anode is 7.4-fold higher compared to bare carbon cloth, which is the highest reported improvement for MFCs with nanomaterial-decorated electrodes. The results of this study offer great potential for advancing the development of microbial electrochemical systems by providing a highly efficient nanomaterial-based electrode that delivers large surface area, high electrochemical activity, and minimum ohmic loss, as well as provide design principles for next-generation nanomaterial-based electrodes that can be broadly applicable for highly efficient microbial electrochemical cells.

  13. Development and Characterization of New Donor-Acceptor Conjugated Polymers and Fullerene Nanoparticles for High Performance Bulk Heterojunction Solar Cells

    DTIC Science & Technology

    2011-01-14

    Nanoparticles for High Performance Bulk Heterojunction Solar Cells Jan. 14,2011 Name of Principal Investigators: Kung-Hwa Wei - e-mail address : khwei...donor-π-bridge-acceptor side chains for high efficiency polymer solar cells . Different from the commonly used linear D-A conjugated polymers, the...Development and Characterization of New Donor-Acceptor Conjugated Polymers and Fullerene Nanoparticles for High Performance Bulk Heterojunction Solar Cells

  14. Fundamental limitations imposed by high doping on the performance of pn junction silicon solar cells

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Li, S. S.; Sah, C. T.

    1975-01-01

    Fundamental limitations imposed on the performance of silicon junction solar cells by physical mechanisms accompanying high doping are described. The one-dimensional mechanisms divide into two broad categories: those associated with band-gap shrinkage and those associated with interband transition rates. By extending the traditional method of analysis and comparing with measurement, it is shown that the latter kind of mechanism dominates in determining the open-circuit voltage in a one-dimensional model of a 0.1 ohm-cm cell at 300 K. As an alternative dominant mechanism, a three-dimensional model involving thermodynamically stable clusters of impurities in the highly-doped diffused layer is suggested.

  15. High Performance Nano-Crystalline Oxide Fuel Cell Materials. Defects, Structures, Interfaces, Transport, and Electrochemistry

    SciTech Connect

    Barnett, Scott; Poeppelmeier, Ken; Mason, Tom; Marks, Lawrence; Voorhees, Peter

    2016-09-07

    This project addresses fundamental materials challenges in solid oxide electrochemical cells, devices that have a broad range of important energy applications. Although nano-scale mixed ionically and electronically conducting (MIEC) materials provide an important opportunity to improve performance and reduce device operating temperature, durability issues threaten to limit their utility and have remained largely unexplored. Our work has focused on both (1) understanding the fundamental processes related to oxygen transport and surface-vapor reactions in nano-scale MIEC materials, and (2) determining and understanding the key factors that control their long-term stability. Furthermore, materials stability has been explored under the “extreme” conditions encountered in many solid oxide cell applications, i.e, very high or very low effective oxygen pressures, and high current density.

  16. Fundamental limitations imposed by high doping on the performance of pn junction silicon solar cells

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Li, S. S.; Sah, C. T.

    1975-01-01

    Fundamental limitations imposed on the performance of silicon junction solar cells by physical mechanisms accompanying high doping are described. The one-dimensional mechanisms divide into two broad categories: those associated with band-gap shrinkage and those associated with interband transition rates. By extending the traditional method of analysis and comparing with measurement, it is shown that the latter kind of mechanism dominates in determining the open-circuit voltage in a one-dimensional model of a 0.1 ohm-cm cell at 300 K. As an alternative dominant mechanism, a three-dimensional model involving thermodynamically stable clusters of impurities in the highly-doped diffused layer is suggested.

  17. High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

    PubMed

    Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

    2017-06-27

    Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm(2) active area and 18% over a 1 cm(2) active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

  18. High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

    2012-01-01

    Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

  19. High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

    2012-01-01

    Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

  20. High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells

    PubMed Central

    Sirdaarta, Joseph; Maen, Anton; Rayan, Paran; Matthews, Ben; Cock, Ian Edwin

    2016-01-01

    g/mL). All other extracts were nontoxic. A total of 145 unique mass signals were detected in the lemon aspen methanolic and aqueous extracts by nonbiased high-performance liquid chromatography-mass spectrometry analysis. Of these, 20 compounds were identified as being of particular interest due to their reported antioxidant and/or anticancer activities. Conclusions: The lack of toxicity and antiproliferative activity of the high antioxidant plant extracts against HeLa and CaCo2 cancer cell lines indicates their potential in the treatment and prevention of some cancers. SUMMARY Australian fruit extracts with high antioxidant contents were potent inhibitors of CaCo2 and HeLa carcinoma cell proliferationMethanolic lemon aspen extract was particularly potent, with IC50 values of 480 μg/mL (HeLa) and 769 μg/mL (CaCo2)High-performance liquid chromatography-mass spectrometry-quadrupole time-of-flight analysis highlighted and putatively identified 20 compounds in the antiproliferative lemon aspen extractsIn contrast, lower antioxidant content extracts stimulated carcinoma cell proliferationAll extracts with antiproliferative activity were nontoxic in the Artemia nauplii assay. Abbreviations used: DPPH: di (phenyl)- (2,4,6-trinitrophenyl) iminoazanium, HPLC: High-performance liquid chromatography, IC50: The concentration required to inhibit by 50%, LC50: The concentration required to achieve 50% mortality, MS: Mass spectrometry. PMID:27279705

  1. High-Performance Inverted Polymer Solar Cells with Zirconium Acetylacetonate Buffer Layers.

    PubMed

    Fan, Haijun; Zhu, Xiaozhang

    2016-12-14

    Inverted polymer solar cells incorporating solution-processed zirconium acetylacetonate (ZrAcac) buffer layers were demonstrated. The optimal device delivered a power conversion efficiency up to 9.2%, displaying ∼20% improvement compared with the device of conventional configuration. The performance improvement by adopting ZrAcac as the cathode buffer layer is attributed to the enhanced light-harvesting, facilitated electron transport, and reduced bimolecular recombination loss. The morphology of ZrAcac buffer layer was found to be critical in achieving high performance, which was tunable through the selection of processing solvents. A flat and uniform ZrAcac film consisting of ∼20 nm nanoscale aggregates deposited from a chloroform solution was proved to be highly effective, which only requires a short light-soaking time.

  2. Epitaxial 1D electron transport layers for high-performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Han, Gill Sang; Chung, Hyun Suk; Kim, Dong Hoe; Kim, Byeong Jo; Lee, Jin-Wook; Park, Nam-Gyu; Cho, In Sun; Lee, Jung-Kun; Lee, Sangwook; Jung, Hyun Suk

    2015-09-01

    We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport.We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport

  3. Solvent Engineering for High-Performance PbS Quantum Dots Solar Cells.

    PubMed

    Wu, Rongfang; Yang, Yuehua; Li, Miaozi; Qin, Donghuan; Zhang, Yangdong; Hou, Lintao

    2017-07-28

    PbS colloidal quantum dots (CQDs) solar cells have already demonstrated very impressive advances in recent years due to the development of many different techniques to tailor the interface morphology and compactness in PbS CQDs thin film. Here, n-hexane, n-octane, n-heptane, isooctane and toluene or their hybrids are for the first time introduced as solvent for comparison of the dispersion of PbS CQDs. PbS CQDs solar cells with the configuration of PbS/TiO₂ heterojunction are then fabricated by using different CQDs solution under ambient conditions. The performances of the PbS CQDs solar cells are found to be tuned by changing solvent and its content in the PbS CQDs solution. The best device could show a power conversion efficiency (PCE) of 7.64% under AM 1.5 G illumination at 100 mW cm(-2) in a n-octane/isooctane (95%/5% v/v) hybrid solvent scheme, which shows a ~15% improvement compared to the control devices. These results offer important insight into the solvent engineering of high-performance PbS CQDs solar cells.

  4. Solvent Engineering for High-Performance PbS Quantum Dots Solar Cells

    PubMed Central

    Wu, Rongfang; Yang, Yuehua; Li, Miaozi; Zhang, Yangdong; Hou, Lintao

    2017-01-01

    PbS colloidal quantum dots (CQDs) solar cells have already demonstrated very impressive advances in recent years due to the development of many different techniques to tailor the interface morphology and compactness in PbS CQDs thin film. Here, n-hexane, n-octane, n-heptane, isooctane and toluene or their hybrids are for the first time introduced as solvent for comparison of the dispersion of PbS CQDs. PbS CQDs solar cells with the configuration of PbS/TiO2 heterojunction are then fabricated by using different CQDs solution under ambient conditions. The performances of the PbS CQDs solar cells are found to be tuned by changing solvent and its content in the PbS CQDs solution. The best device could show a power conversion efficiency (PCE) of 7.64% under AM 1.5 G illumination at 100 mW cm−2 in a n-octane/isooctane (95%/5% v/v) hybrid solvent scheme, which shows a ~15% improvement compared to the control devices. These results offer important insight into the solvent engineering of high-performance PbS CQDs solar cells. PMID:28788077

  5. Performance of particle in cell methods on highly concurrent computational architectures

    NASA Astrophysics Data System (ADS)

    Adams, M. F.; Ethier, S.; Wichmann, N.

    2007-07-01

    Particle in cell (PIC) methods are effective in computing Vlasov-Poisson system of equations used in simulations of magnetic fusion plasmas. PIC methods use grid based computations, for solving Poisson's equation or more generally Maxwell's equations, as well as Monte-Carlo type methods to sample the Vlasov equation. The presence of two types of discretizations, deterministic field solves and Monte-Carlo methods for the Vlasov equation, pose challenges in understanding and optimizing performance on today large scale computers which require high levels of concurrency. These challenges arises from the need to optimize two very different types of processes and the interactions between them. Modern cache based high-end computers have very deep memory hierarchies and high degrees of concurrency which must be utilized effectively to achieve good performance. The effective use of these machines requires maximizing concurrency by eliminating serial or redundant work and minimizing global communication. A related issue is minimizing the memory traffic between levels of the memory hierarchy because performance is often limited by the bandwidths and latencies of the memory system. This paper discusses some of the performance issues, particularly in regard to parallelism, of PIC methods. The gyrokinetic toroidal code (GTC) is used for these studies and a new radial grid decomposition is presented and evaluated. Scaling of the code is demonstrated on ITER sized plasmas with up to 16K Cray XT3/4 cores.

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

    PubMed

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

    2015-09-16

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

  7. High-performance liquid-catalyst fuel cell for direct biomass-into-electricity conversion.

    PubMed

    Liu, Wei; Mu, Wei; Deng, Yulin

    2014-12-01

    Herein, we report high-performance fuel cells that are catalyzed solely by polyoxometalate (POM) solution without any solid metal or metal oxide. The novel design of the liquid-catalyst fuel cells (LCFC) changes the traditional gas-solid-surface heterogeneous reactions to liquid-catalysis reactions. With this design, raw biomasses, such as cellulose, starch, and even grass or wood powders can be directly converted into electricity. The power densities of the fuel cell with switchgrass (dry powder) and bush allamanda (freshly collected) are 44 mW cm(-2) and 51 mW cm(-2) respectively. For the cellulose-based biomass fuel cell, the power density is almost 3000 times higher than that of cellulose-based microbial fuel cells. Unlike noble-metal catalysts, POMs are tolerant to most organic and inorganic contaminants. Therefore, almost any raw biomass can be used directly to produce electricity without prior purification. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Materials and Modules for Low Cost, High Performance Fuel Cell Humidifiers

    SciTech Connect

    Johnson, William B

    2012-12-31

    The objective of this program was to demonstrate a durable, high performance water transport membrane; and a compact, low-cost, membrane-based module utilizing that membrane for use in an automotive, stationary and/or portable fuel cell water transport exchangers. Over the past 20 years, great technical progress has been made in improving power density and durability of fuel cell stacks. Yet, operating durably at high performance levels under very dry conditions, e.g., < 20% RH at 80°C or above, remains beyond even the best fuel cell membrane electrode assemblies. Thus, today it is essential to humidify the gases supplied to the fuel cell inlets. In this work, we have produced a new, inexpensive, composite membrane capable of very high water vapor transport and low air cross-over. The composite structure consists of a very thin ionomer layer (e.g., < 5 micron) sandwiched between two microporous polymer layers. The thin ionomer layer facilitates the rapid water transport and provides an impermeable layer to prevent gas cross-over. Such an approach reduces cost, but maintains performance. The microporous layer protects the thin ionomer layer from mechanical damage during handling; confers strength to the thin layer allowing it to be more durable during use; and allows it to withstand higher automotive pressures and temperatures. The composite structure will therefore allow lower total cost while still meeting automotive humidifier water transport and durability targets. Because the transport rates of these new materials are so high, existing planar membrane humidifier module designs available at the start of the program were incapable of efficiently utilizing the high rates. Therefore, the assembled team designed, tested and demonstrated an innovative, low-cost humidifier module with customized channel geometries that can take advantage of the high the water transport rates. The objectives of the program have been fully met. The optimized membrane produced in the

  9. Solution-Processable Organic Molecule for High-Performance Organic Solar Cells with Low Acceptor Content.

    PubMed

    Wang, Kun; Guo, Bing; Xu, Zhuo; Guo, Xia; Zhang, Maojie; Li, Yongfang

    2015-11-11

    A new planar D2-A-D1-A-D2 structured organic molecule with bithienyl benzodithiophene (BDT) as central donor unit D1 and fluorine-substituted benzothiadiazole (BTF) as acceptor unit and alkyl-dithiophene as end group and donor unit D2, BDT-BTF, was designed and synthesized for the application as donor material in organic solar cells (OSCs). BDT-BTF shows a broad absorption in visible region, suitable highest occupied molecular orbital energy level of -5.20 eV, and high hole mobility of 1.07 × 10(-2) cm(2)/(V s), benefitted from its high coplanarity and strong crystallinity. The OSCs based on BDT-BTF as donor (D) and PC71BM as acceptor (A) at a D/A weight ratio of 3:1 without any extra treatment exhibit high photovoltaic performance with Voc of 0.85 V, Jsc of 10.48 mA/cm(2), FF of 0.66, and PCE of 5.88%. The morphological study by transmission electron microscopy reveals that the blend of BDT-BTF and PC71BM (3:1, w/w) possesses an appropriate interpenetrating D/A network for the exciton separation and charge carrier transport, which agrees well with the good device performance. The optimized D/A weight ratio of 3:1 is the lowest acceptor content in the active layer reported so far for the high-performance OSCs, and the organic molecules with the molecular structure like BDT-BTF could be promising high-performance donor materials in solution-processable OSCs.

  10. Three-dimensional carbon nanotube-textile anode for high-performance microbial fuel cells.

    PubMed

    Xie, Xing; Hu, Liangbing; Pasta, Mauro; Wells, George F; Kong, Desheng; Criddle, Craig S; Cui, Yi

    2011-01-12

    Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Anode performance is an important factor limiting the power density of MFCs for practical application. Improving the anode design is thus important for enhancing the MFC performance, but only a little development has been reported. Here, we describe a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube-textile (CNT-textile) composite for high-performance MFCs. The macroscale porous structure of the intertwined CNT-textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte-biofilm-anode interfacial area than the projective surface area of the CNT-textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT-textile anode. An MFC equipped with a CNT-textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater.

  11. [Determination of vincristini sulfas in tumor cells by high performance liquid chromatography].

    PubMed

    Li, D; Tu, W; Li, L; Tang, D; Huang, W

    1998-01-01

    Vincristini sulfas (VCR) is an important common antitumor drug. The resistance to anticancer drug is the main cause of the chemotherapy failure. To screen the drugs which can reverse VCR resistance for VCR resistant cell strain, an analytical method has been established for the determination of VCR concentration in tumor cells using high performance liquid chromatography (HPLC). The stainless steel column was 25 cm x 4.6 mm i.d. packed with totally porous, spherical silica particles (5 microns). A solution of methanol and 0.02 mol/L dipotassium hydrogen phosphate (80:20, V/V) adjusted to pH 6.6 with H3PO4 was employed as the mobile phase. The flow rate was 1 mL/min. Chromatography was performed with ultraviolet detector at 267 nm. The method is simple, rapid and selective. Linear calibration curve for VCR was measured within the range of 10 to 200 mg/L with correlation coefficient of 0.999 8. The lowest detection limit was 4 mg/L tumor cells extract. The HPLC method described is suitable for clinical monitoring and pharmacokinetic study of VGR.

  12. Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

    NASA Astrophysics Data System (ADS)

    Tan, Miao; Zhong, Sihua; Wang, Wenjie; Shen, Wenzhong

    2017-08-01

    We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H) solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i) the work function of the transparent conductive oxide layer, (ii) the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) interface, (iii) the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H) layer, and (iv) the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT) counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

  13. High-Performance Chemically Regenerative Redox Fuel Cells Using a NO3(-) /NO Regeneration Reaction.

    PubMed

    Han, Sang-Beom; Kwak, Da-Hee; Park, Hyun Suk; Choi, In-Ae; Park, Jin-Young; Kim, Si-Jin; Kim, Min-Cheol; Hong, Seongho; Park, Kyung-Won

    2017-03-06

    In this study, we proposed high-performance chemically regenerative redox fuel cells (CRRFCs) using NO3(-) /NO with a nitrogen-doped carbon-felt electrode and a chemical regeneration reaction of NO to NO3(-) via O2 . The electrochemical cell using the nitrate reduction to NO at the cathode on the carbon felt and oxidation of H2 as a fuel at the anode showed a maximal power density of 730 mW cm(-2) at 80 °C and twofold higher power density of 512 mW cm(-2) at 0.8 V, than the target power density of 250 mW cm(-2) at 0.8 V in the H2 /O2 proton exchange membrane fuel cells (PEMFCs). During the operation of the CRRFCs with the chemical regeneration reactor for 30 days, the CRRFCs maintained 60 % of the initial performance with a regeneration efficiency of about 92.9 % and immediately returned to the initial value when supplied with fresh HNO3 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Stable operation of air-blowing direct methanol fuel cells with high performance

    NASA Astrophysics Data System (ADS)

    Park, Jun-Young; Lee, Jin-Hwa; Kim, Jirae; Han, Sangil; Song, Inseob

    A membrane electrode assembly (MEA) that is a combination of a catalyst-coated membrane (CCM) for the anode and a catalyst-coated substrate (CCS) for the cathode is studied under air-blower conditions for direct methanol fuel cells (DMFCs). Compared with MEAs prepared by only the CCS method, the performance of DMFC MEAs employing the combination method is significantly improved by 30% with less methanol crossover. This feature can be attributed to an enhanced electrode|membrane interface in the anode side and significantly higher catalyst efficiency. Furthermore, DMFC MEAs designed by the combination method retain high power density without any degradation, while the CCM-type cell shows a downward tendency in electrochemical performance under air-blower conditions. This may be due to MEAs with CCM have a much more difficult structure of catalytic active sites in the cathode to eliminate the water produced by electrochemical reaction. In addition, DMFCs produced via combination methods exhibit a lower water crossover flux than CCS alternatives, due to the comparatively dense structure of the CCM anode. Hence, DMFCs with a combination MEA structure demonstrate the feasibility of a small fuel cell system employing the low noise of a fan, instead of a noisy and large capacity air pump, for portable electronic devices.

  15. Metal chloride-treated graphene oxide to produce high-performance polymer solar cells

    SciTech Connect

    Choi, Eun-Su; Noh, Yong-Jin; Kwon, Sung-Nam; Na, Seok-In; Jeon, Ye-Jin; Kim, Seok-Soon; Kim, Tae-Wook

    2015-07-13

    We introduce a simple but effective graphene oxide (GO) modification with metal chloride treatments to produce high-performance polymer solar cells (PSCs). The role of various metal chlorides on GO and their effects on device performances of PSCs was investigated. X-ray photoelectron spectroscopy, ultraviolet photoemission spectroscopy, and current-voltage measurement studies demonstrated that metal chloride can induce a p-doping effect and increase the GO work-function, thus resulting in an improved built-in potential and interfacial resistance in PSCs. The resultant PSCs with metal chloride exhibited improved device efficiency than those with the neat GO. Furthermore, with the metal chloride-doped GO, we finally achieved an excellent PSC-efficiency of 6.58% and a very desirable device stability, which constitute a highly similar efficiency but much better PSC life-time to conventional device with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). This study could be a valuable way to produce various PEDOT:PSS alternatives and beneficial for producing high-performance and cost-efficient polymeric devices.

  16. High-performance hybrid organic-inorganic solar cell based on planar n-type silicon

    NASA Astrophysics Data System (ADS)

    Chi, Dan; Qi, Boyuan; Wang, Jizheng; Qu, Shengchun; Wang, Zhanguo

    2014-05-01

    Hybrid organic-inorganic solar cells were fabricated by spin coating the hole transporting conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film on n-type crystalline silicon (n-Si). By incorporating different additives into the PEDOT:PSS, the conductivity and wettability of PEDOT:PSS film are markedly improved, and the device performance is greatly enhanced accordingly. To further optimize the device performance, poly(3-hexylthiophene) (P3HT) layer was inserted between the n-Si and PEDOT:PSS layer. The P3HT layer blocks electrons from diffusing to the PEDOT:PSS, and hence reduces recombination at the anode side. The device eventually exhibits a high power conversion efficiency of 11.52%.

  17. Oxasmaragdyrins as New and Efficient Hole-Transporting Materials for High-Performance Perovskite Solar Cells.

    PubMed

    Mane, Sandeep B; Sutanto, Albertus Adrian; Cheng, Chih-Fu; Xie, Meng-Yu; Chen, Chieh-I; Leonardus, Mario; Yeh, Shih-Chieh; Beyene, Belete Bedemo; Diau, Eric Wei-Guang; Chen, Chin-Ti; Hung, Chen-Hsiung

    2017-09-06

    The high performance of the perovskite solar cells (PSCs) cannot be achieved without a layer of efficient hole-transporting materials (HTMs) to retard the charge recombination and transport the photogenerated hole to the counterelectrode. Herein, we report the use of boryl oxasmaragdyrins (SM01, SM09, and SM13), a family of aromatic core-modified expanded porphyrins, as efficient hole-transporting materials (HTMs) for perovskite solar cells (PSCs). These oxasmaragdyrins demonstrated complementary absorption spectra in the low-energy region, good redox reversibility, good thermal stability, suitable energy levels with CH3NH3PbI3 perovskite, and high hole mobility. A remarkable power conversion efficiency of 16.5% (Voc = 1.09 V, Jsc = 20.9 mA cm(-2), fill factor (FF) = 72%) is achieved using SM09 on the optimized PSCs device employing a planar structure, which is close to that of the state-of-the-art hole-transporting materials (HTMs), spiro-OMeTAD of 18.2% (Voc = 1.07 V, Jsc = 22.9 mA cm(-2), FF = 74%). In contrast, a poor photovoltaic performance of PSCs using SM01 is observed due to the interactions of terminal carboxylic acid functional group with CH3NH3PbI3.

  18. Solvent engineering for high-performance inorganic-organic hybrid perovskite solar cells.

    PubMed

    Jeon, Nam Joong; Noh, Jun Hong; Kim, Young Chan; Yang, Woon Seok; Ryu, Seungchan; Seok, Sang Il

    2014-09-01

    Organolead trihalide perovskite materials have been successfully used as light absorbers in efficient photovoltaic cells. Two different cell structures, based on mesoscopic metal oxides and planar heterojunctions have already demonstrated very impressive advances in performance. Here, we report a bilayer architecture comprising the key features of mesoscopic and planar structures obtained by a fully solution-based process. We used CH3NH3 Pb(I(1-x)Br(x))3 (x = 0.1-0.15) as the absorbing layer and poly(triarylamine) as a hole-transporting material. The use of a mixed solvent of γ-butyrolactone and dimethylsulphoxide (DMSO) followed by toluene drop-casting leads to extremely uniform and dense perovskite layers via a CH3NH3I-PbI2-DMSO intermediate phase, and enables the fabrication of remarkably improved solar cells with a certified power-conversion efficiency of 16.2% and no hysteresis. These results provide important progress towards the understanding of the role of solution-processing in the realization of low-cost and highly efficient perovskite solar cells.

  19. High-Performance Nonfullerene Polymer Solar Cells based on Imide-Functionalized Wide-Bandgap Polymers.

    PubMed

    Fan, Baobing; Zhang, Kai; Jiang, Xiao-Fang; Ying, Lei; Huang, Fei; Cao, Yong

    2017-03-23

    High-performance nonfullerene polymer solar cells (PSCs) are developed by integrating the nonfullerene electron-accepting material 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophne) (ITIC) with a wide-bandgap electron-donating polymer PTzBI or PTzBI-DT, which consists of an imide functionalized benzotriazole (TzBI) building block. Detailed investigations reveal that the extension of conjugation can affect the optical and electronic properties, molecular aggregation properties, charge separation in the bulk-heterojunction films, and thus the overall photovoltaic performances. Single-junction PSCs based on PTzBI:ITIC and PTzBI-DT:ITIC exhibit remarkable power conversion efficiencies (PCEs) of 10.24% and 9.43%, respectively. To our knowledge, these PCEs are the highest efficiency values obtained based on electron-donating conjugated polymers consisting of imide-functionalized electron-withdrawing building blocks. Of particular interest is that the resulting device based on PTzBI exhibits remarkable PCE of 7% with the thickness of active layer of 300 nm, which is among the highest values of nonfullerene PSCs utilizing thick photoactive layer. Additionally, the device based on PTzBI:ITIC exhibits prominent stability, for which the PCE remains as 9.34% after thermal annealing at 130 °C for 120 min. These findings demonstrate the great promise of using this series of wide-bandgap conjugated polymers as electron-donating materials for high-performance nonfullerene solar cells toward high-throughput roll-to-roll processing technology.

  20. Three-dimensional porous carbon nanotube sponges for high-performance anodes of microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Erbay, Celal; Yang, Gang; de Figueiredo, Paul; Sadr, Reza; Yu, Choongho; Han, Arum

    2015-12-01

    Highly-porous, light-weight, and inexpensive three-dimensional (3D) sponges consisting of interconnected carbon nanotubes (CNTs) without base materials are synthesized with a facile and scalable one-step chemical vapor deposition process as anode of microbial fuel cells (MFCs). The MFCs generates higher power densities of 2150 W m-3 (per anode volume) or 170 W m-3 (per anode chamber volume), comparable to those of commercial 3D carbon felt electrodes under the same conditions. The high performances are due to excellent charge transfer between CNTs and microbes owing to 13 times lower charge transfer resistance compared to that of carbon felt. The material cost of producing these CNT sponge estimates to be ∼0.1/gCNT, significantly lower than that of other methods. In addition, the high production rate of about 3.6 g h-1 compared to typical production rate of 0.02 g h-1 of other CNT-based materials makes this process economically viable. The one-step synthesis method allowing self-assembly of 3D CNT sponges as they grow is low cost and scalable, making this a promising method for manufacturing high-performance anodes of MFCs, with broad applicability to microbial electrochemical systems in general.

  1. Highly nitrogen-doped carbon capsules: scalable preparation and high-performance applications in fuel cells and lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Hu, Chuangang; Xiao, Ying; Zhao, Yang; Chen, Nan; Zhang, Zhipan; Cao, Minhua; Qu, Liangti

    2013-03-01

    Highly nitrogen-doped carbon capsules (hN-CCs) have been successfully prepared by using inexpensive melamine and glyoxal as precursors via solvothermal reaction and carbonization. With a great promise for large scale production, the hN-CCs, having large surface area and high-level nitrogen content (N/C atomic ration of ca. 13%), possess superior crossover resistance, selective activity and catalytic stability towards oxygen reduction reaction for fuel cells in alkaline medium. As a new anode material in lithium-ion battery, hN-CCs also exhibit excellent cycle performance and high rate capacity with a reversible capacity of as high as 1046 mA h g-1 at a current density of 50 mA g-1 after 50 cycles. These features make the hN-CCs developed in this study promising as suitable substitutes for the expensive noble metal catalysts in the next generation alkaline fuel cells, and as advanced electrode materials in lithium-ion batteries.Highly nitrogen-doped carbon capsules (hN-CCs) have been successfully prepared by using inexpensive melamine and glyoxal as precursors via solvothermal reaction and carbonization. With a great promise for large scale production, the hN-CCs, having large surface area and high-level nitrogen content (N/C atomic ration of ca. 13%), possess superior crossover resistance, selective activity and catalytic stability towards oxygen reduction reaction for fuel cells in alkaline medium. As a new anode material in lithium-ion battery, hN-CCs also exhibit excellent cycle performance and high rate capacity with a reversible capacity of as high as 1046 mA h g-1 at a current density of 50 mA g-1 after 50 cycles. These features make the hN-CCs developed in this study promising as suitable substitutes for the expensive noble metal catalysts in the next generation alkaline fuel cells, and as advanced electrode materials in lithium-ion batteries. Electronic supplementary information (ESI) available: More experimental details and characterization. See DOI: 10

  2. A new class of semiconducting polymers for bulk heterojunction solar cells with exceptionally high performance.

    PubMed

    Liang, Yongye; Yu, Luping

    2010-09-21

    Solar cells based on the polymer-fullerene bulk heterojunction (BHJ) concept are an attractive class of low-cost solar energy harvesting devices. Because the power conversion efficiency (PCE) of these solar cells is still significantly lower than that of their inorganic counterparts, however, materials design and device engineering efforts are directed toward improving their output. A variety of factors limit the performance of BHJ solar cells, but the properties of the materials in the active layer are the primary determinant of their overall efficiency. The ideal polymer in a BHJ structure should exhibit the following set of physical properties: a broad absorption with high coefficient in the solar spectrum to efficiently harvest solar energy, a bicontinuous network with domain width within twice that of the exciton diffusion length, and high donor-acceptor interfacial area to favor exciton dissociation and efficient transport of separated charges to the respective electrodes. To facilitate exciton dissociation, the lowest unoccupied molecular orbital (LUMO) energy level of the donor must have a proper match with that of the acceptor to provide enough driving force for charge separation. The polymer should have a low-lying highest occupied molecular orbital (HOMO) energy level to provide a large open circuit voltage (V(oc)). All of these desired properties must be synergistically integrated to maximize solar cell performance. However, it is difficult to design a polymer to fulfill all these requirements. In this Account, we summarize our recent progress in developing a new class of semiconducting polymers, which represents the first polymeric system to generate solar PCE greater than 7%. The polymer system is composed of thieno[3,4-b]thiophene and benzodithiophene alternating units. These polymers have low bandgaps and exhibit efficient absorption throughout the region of greatest photon flux in the solar spectrum (around 700 nm). The stabilization of the

  3. Effect of high somatic cell counts on reproductive performance of Chilean dairy cattle.

    PubMed

    Pinedo, P J; Melendez, P; Villagomez-Cortes, J A; Risco, C A

    2009-04-01

    The objectives were to evaluate the effect of high linear somatic cell counts (LNSCC > or =4.5) during early lactation on reproductive performance and to estimate their association with the risk of abortion in a population of central-southern Chilean dairy cattle. The analysis included records from a population of 157 farms and considered 1,127,405 test-day records including 101,944 lactations that began between 1997 and 2006. After data edits, the analyses of calving to first service and calving to conception intervals consisted of 88,633 and 70,877 lactations, respectively. Once controlling for significant variables, time to first breeding was 21.8 d longer in cows with at least 1 high LNSCC before the first breeding compared with controls. Cows with at least 1 high LNSCC before the fertile breeding had an increment in time to conception of 48.7 d and required, on average, 0.49 more services to conceive. The odds of conception at first service in cows with a high LNSCC within 30 d before [after] breeding were 0.85 (0.81 to 0.89; 95% confidence interval ) [0.82 (0.78 to 0.87; 95% confidence interval)] times the odds of conception for cows without a high LNSCC during that period. The Cox proportional hazard model indicated that after correction by calving year, lactation number, and milk yield standardized to 305 d, the risk of pregnancy decreased by 44% if a high LNSCC occurred before breeding. Cows registering a high LNSCC during the first 90 d of gestation had an increased risk of abortion, being 1.22 (1.07 to 1.35; 95% confidence interval) times more likely to abort than nonaffected cows. It is concluded that subclinical mastitis, measured as LNSCC >/=4.5, had a significant effect on reproductive performance in Chilean dairy cattle.

  4. Atomistic Origins of High-Performance in Hybrid Halide Perovskite Solar Cells

    PubMed Central

    2014-01-01

    The performance of organometallic perovskite solar cells has rapidly surpassed that of both conventional dye-sensitized and organic photovoltaics. High-power conversion efficiency can be realized in both mesoporous and thin-film device architectures. We address the origin of this success in the context of the materials chemistry and physics of the bulk perovskite as described by electronic structure calculations. In addition to the basic optoelectronic properties essential for an efficient photovoltaic device (spectrally suitable band gap, high optical absorption, low carrier effective masses), the materials are structurally and compositionally flexible. As we show, hybrid perovskites exhibit spontaneous electric polarization; we also suggest ways in which this can be tuned through judicious choice of the organic cation. The presence of ferroelectric domains will result in internal junctions that may aid separation of photoexcited electron and hole pairs, and reduction of recombination through segregation of charge carriers. The combination of high dielectric constant and low effective mass promotes both Wannier-Mott exciton separation and effective ionization of donor and acceptor defects. The photoferroic effect could be exploited in nanostructured films to generate a higher open circuit voltage and may contribute to the current–voltage hysteresis observed in perovskite solar cells. PMID:24684284

  5. Room temperature, air crystallized perovskite film for high performance solar cells

    SciTech Connect

    Dubey, Ashish; Kantack, Nicholas; Adhikari, Nirmal; Reza, Khan Mamun; Venkatesan, Swaminathan; Kumar, Mukesh; Khatiwada, Devendra; Darling, Seth; Qiao, Qiquan

    2016-05-31

    For the first time, room temperature heating free growth and crystallization of perovskite films in ambient air without the use of thermal annealing is reported. Highly efficient perovskite nanorod-based solar cells were made using ITO/PEDOT:PSS/CH3NH3PbI3 nanorods/PC60BM/rhodamine/Ag. All the layers except PEDOT:PSS were processed at room temperature thereby eliminating the need for thermal treatment. Perovskite films were spin coated inside a N-2 filled glovebox and immediately were taken outside in air having 40% relative humidity (RH). Exposure to humid air was observed to promote the crystallization process in perovskite films even at room temperature. Perovskite films kept for 5 hours in ambient air showed nanorod-like morphology having high crystallinity, with devices exhibiting the highest PCE of 16.83%, which is much higher than the PCE of 11.94% for traditional thermally annealed perovskite film based devices. Finally, it was concluded that moisture plays an important role in room temperature crystallization of pure perovskite nanorods, showing improved optical and charge transport properties, which resulted in high performance solar cells.

  6. Room temperature, air crystallized perovskite film for high performance solar cells

    DOE PAGES

    Dubey, Ashish; Kantack, Nicholas; Adhikari, Nirmal; ...

    2016-05-31

    For the first time, room temperature heating free growth and crystallization of perovskite films in ambient air without the use of thermal annealing is reported. Highly efficient perovskite nanorod-based solar cells were made using ITO/PEDOT:PSS/CH3NH3PbI3 nanorods/PC60BM/rhodamine/Ag. All the layers except PEDOT:PSS were processed at room temperature thereby eliminating the need for thermal treatment. Perovskite films were spin coated inside a N-2 filled glovebox and immediately were taken outside in air having 40% relative humidity (RH). Exposure to humid air was observed to promote the crystallization process in perovskite films even at room temperature. Perovskite films kept for 5 hours inmore » ambient air showed nanorod-like morphology having high crystallinity, with devices exhibiting the highest PCE of 16.83%, which is much higher than the PCE of 11.94% for traditional thermally annealed perovskite film based devices. Finally, it was concluded that moisture plays an important role in room temperature crystallization of pure perovskite nanorods, showing improved optical and charge transport properties, which resulted in high performance solar cells.« less

  7. Room temperature, air crystallized perovskite film for high performance solar cells

    SciTech Connect

    Dubey, Ashish; Kantack, Nicholas; Adhikari, Nirmal; Reza, Khan Mamun; Venkatesan, Swaminathan; Kumar, Mukesh; Khatiwada, Devendra; Darling, Seth; Qiao, Qiquan

    2016-05-31

    For the first time, room temperature heating free growth and crystallization of perovskite films in ambient air without the use of thermal annealing is reported. Highly efficient perovskite nanorod-based solar cells were made using ITO/PEDOT:PSS/CH3NH3PbI3 nanorods/PC60BM/rhodamine/Ag. All the layers except PEDOT:PSS were processed at room temperature thereby eliminating the need for thermal treatment. Perovskite films were spin coated inside a N-2 filled glovebox and immediately were taken outside in air having 40% relative humidity (RH). Exposure to humid air was observed to promote the crystallization process in perovskite films even at room temperature. Perovskite films kept for 5 hours in ambient air showed nanorod-like morphology having high crystallinity, with devices exhibiting the highest PCE of 16.83%, which is much higher than the PCE of 11.94% for traditional thermally annealed perovskite film based devices. Finally, it was concluded that moisture plays an important role in room temperature crystallization of pure perovskite nanorods, showing improved optical and charge transport properties, which resulted in high performance solar cells.

  8. High performance polymer solar cells with as-prepared zirconium acetylacetonate film as cathode buffer layer

    PubMed Central

    Tan, Zhan'ao; Li, Shusheng; Wang, Fuzhi; Qian, Deping; Lin, Jun; Hou, Jianhui; Li, Yongfang

    2014-01-01

    Low-work-function active metals are commonly used as cathode in polymer solar cells (PSCs), but sensitivity of the active metals towards moisture and oxygen results in poor stability of the devices. Therefore, solution-proceessable and stable cathode buffer layer is of great importance for the application of PSCs. Here we demonstrate high performance PSCs by employing as-prepared zirconium acetylacetonate (a-ZrAcac) film spin-cast from its ethanol solution as cathode buffer layer. The PSCs based on a low bandgap polymer PBDTBDD as donor and PC60BM as acceptor with a-ZrAcac/Al cathode demonstrated an average power conversion efficiency (PCE) of 8.75% which is significantly improved than that of the devices with traditional Ca/Al cathode. The improved photovoltaic performance is benefitted from the decreased series resistance and enhanced light harvest of the PSCs with the a-ZrAcac/Al cathode. The results indicate that a-ZrAcac is a promising high performance cathode buffer layer for fabricating large area flexible PSCs. PMID:24732976

  9. A passive microfluidic hydrogen-air fuel cell with exceptional stability and high performance.

    PubMed

    Mitrovski, Svetlana M; Nuzzo, Ralph G

    2006-03-01

    We describe an advanced microfluidic hydrogen-air fuel cell (FC) that exhibits exceptional durability and high performance, most notably yielding stable output power (>100 days) without the use of an anode-cathode separator membrane. This FC embraces an entirely passive device architecture and, unlike conventional microfluidic designs that exploit laminar hydrodynamics, no external pumps are used to sustain or localize the reagent flow fields. The devices incorporate high surface area/porous metal and metal alloy electrodes that are embedded and fully immersed in liquid electrolyte confined in the channels of a poly(dimethylsiloxane) (PDMS)-based microfluidic network. The polymeric network also serves as a self-supporting membrane through which oxygen and hydrogen are supplied to the cathode and alloy anode, respectively, by permeation. The operational stability of the device and its performance is strongly dependent on the nature of the electrolyte used (5 M H2SO4 or 2.5 M NaOH) and composition of the anode material. The latter choice is optimized to decrease the sensitivity of the system to oxygen cross-over while still maintaining high activity towards the hydrogen oxidation reaction (HOR). Three types of high surface area anodes were tested in this work. These include: high-surface area electrodeposited Pt (Pt); high-surface area electrodeposited Pd (Pd); and thin palladium adlayers supported on a "porous" Pt electrode (Pd/Pt). The FCs display their best performance in 5 M H2SO4 using the Pd/Pt anode. This exceptional stability and performance was ascribed to several factors, namely: the high permeabilities of O2, H2, and CO2 in PDMS; the inhibition of the formation of insoluble carbonate species due to the presence of a highly acidic electrolyte; and the selectivity of the Pd/Pt anode toward the HOR. The stability of the device for long-term operation was modeled using a stack of three FCs as a power supply for a portable display that otherwise uses a 3 V

  10. High performance solar cells: It's all about the optics (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yablonovitch, Eli

    2016-09-01

    For solar cells at 25%, good electron-hole transport is already a given. Further improvements of efficiency above 25% are all about the photon management! Our mantra is: "A good solar cell has to be a good LED; A great solar cell has to be a great LED! It has been found that thin-film cells are more efficient than the best wafer cells. Even more counter-intuitively, solar cells perform best when some of the solar photons are returned as external fluorescence. That is, the external luminescence yield ext, should be maximized. Good external fluorescence produces record output voltage.

  11. Final Report: Materials and Modules for Low Cost, High Performance Fuel Cell Humidifiers

    SciTech Connect

    Johnson, William B

    2012-12-31

    Over the past 20 years, great technical progress has been made in improving power density and durability of fuel cell stacks. Yet, operating durably at high performance levels under very dry conditions, e.g., < 20% RH at 80 °C or above, remains beyond even the best fuel cell membrane electrode assemblies. Thus, today it is essential to humidify the gases supplied to the fuel cell inlets. In this work, we have produced a new, inexpensive, composite membrane capable of very high water vapor transport and low air cross-over. The composite structure consists of a very thin ionomer layer (e.g., < 5 m) sandwiched between two microporous polymer layers. The thin ionomer layer facilitates the rapid water transport and provides an impermeable layer to prevent gas cross-over. Such an approach reduces cost, but maintains performance. The microporous layer protects the thin ionomer layer from mechanical damage during handling; confers strength to the thin layer allowing it to be more durable during use; and allows it to withstand higher automotive pressures and temperatures. The composite structure will therefore allow lower total cost while still meeting automotive humidifier water transport and durability targets. Because the transport rates of these new materials are so high, existing planar membrane humidifier module designs available at the start of the program were incapable of efficiently utilizing the high rates. Therefore, the assembled team designed, tested and demonstrated an innovative, low-cost humidifier module with customized channel geometries that can take advantage of the high the water transport rates. Program Results The objectives of the program have been fully met. The optimized membrane produced in the program has very high transport rates, nearly twice that of the closest competitive option, a homogeneous perfluorosulfonic acid (PFSA) membrane. Furthermore, the composite structure imparts significant durability advantages, allowing the membrane to

  12. Performance, Performance System, and High Performance System

    ERIC Educational Resources Information Center

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  13. High performance zirconia-bismuth oxide nanocomposite electrolytes for lower temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Joh, Dong Woo; Park, Jeong Hwa; Kim, Do Yeub; Yun, Byung-Hyun; Lee, Kang Taek

    2016-07-01

    We develop a novel nanocomposite electrolyte, consisting of yttria-stabilized zirconia (YSZ) and erbia-stabilized bismuth oxide (ESB). The 20 mol% ESB-incorporated YSZ composite (20ESB-YSZ) achieves the high density (>97%) at the low sintering temperature of 800 °C. The microstructural analysis of 20ESB-YSZ reveals the characteristic nanocomposite structure of the highly percolated ESB phase at the YSZ grain boundaries (a few ∼ nm thick). The ionic conductivity of 20ESB-YSZ is increased by 5 times compared to that of the conventional YSZ due to the fast oxygen ion transport along the ESB phase. Moreover, this high conductivity is maintained up to 580 h, indicating high stability of the ESB-YSZ nanocomposite. In addition, the oxygen reduction reaction at the composite electrolyte/cathode interface is effectively enhanced (∼70%) at the temperature below 650 °C, mainly due to the fast dissociative oxygen adsorption on the ESB surface as well as the rapid oxygen ion incorporation into the ESB lattice. Thus, we believe this ESB-YSZ nanocomposite is a promising electrolyte for high performance solid oxide fuel cells at reduced temperatures.

  14. Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells

    PubMed Central

    Hedley, Gordon J.; Ward, Alexander J.; Alekseev, Alexander; Howells, Calvyn T.; Martins, Emiliano R.; Serrano, Luis A.; Cooke, Graeme; Ruseckas, Arvydas; Samuel, Ifor D. W.

    2013-01-01

    The morphology of bulk heterojunction organic photovoltaic cells controls many of the performance characteristics of devices. However, measuring this morphology is challenging because of the small length-scales and low contrast between organic materials. Here we use nanoscale photocurrent mapping, ultrafast fluorescence and exciton diffusion to observe the detailed morphology of a high-performance blend of PTB7:PC71BM. We show that optimized blends consist of elongated fullerene-rich and polymer-rich fibre-like domains, which are 10–50 nm wide and 200–400 nm long. These elongated domains provide a concentration gradient for directional charge diffusion that helps in the extraction of charge pairs with 80% efficiency. In contrast, blends with agglomerated fullerene domains show a much lower efficiency of charge extraction of ~45%, which is attributed to poor electron and hole transport. Our results show that the formation of narrow and elongated domains is desirable for efficient bulk heterojunction solar cells. PMID:24343223

  15. Highly nitrogen-doped carbon capsules: scalable preparation and high-performance applications in fuel cells and lithium ion batteries.

    PubMed

    Hu, Chuangang; Xiao, Ying; Zhao, Yang; Chen, Nan; Zhang, Zhipan; Cao, Minhua; Qu, Liangti

    2013-04-07

    Highly nitrogen-doped carbon capsules (hN-CCs) have been successfully prepared by using inexpensive melamine and glyoxal as precursors via solvothermal reaction and carbonization. With a great promise for large scale production, the hN-CCs, having large surface area and high-level nitrogen content (N/C atomic ration of ca. 13%), possess superior crossover resistance, selective activity and catalytic stability towards oxygen reduction reaction for fuel cells in alkaline medium. As a new anode material in lithium-ion battery, hN-CCs also exhibit excellent cycle performance and high rate capacity with a reversible capacity of as high as 1046 mA h g(-1) at a current density of 50 mA g(-1) after 50 cycles. These features make the hN-CCs developed in this study promising as suitable substitutes for the expensive noble metal catalysts in the next generation alkaline fuel cells, and as advanced electrode materials in lithium-ion batteries.

  16. Identification of some key parameters limiting the performance of high-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Mokashi, Anant R.; Daud, Taher; Kachare, Ram H.

    1986-01-01

    This paper presents, for the first time, a detailed sensitivity analysis of key cell parameters on silicon-cell efficiency by incorporating advanced solar cell physics in a sophisticated numerical simulation program. It delineates the true physical barriers to obtaining a high-efficiency silicon solar cell. Specific parameters presently limiting cell efficiency are identified to be the minority carrier lifetime and the recombination velocities at the front and back surfaces. Practical cell efficiencies in the vicinity of 22 percent are estimated to be attainable by using good quality silicon crystal and substantially reducing surface recombination velocities.

  17. Towards high performance computing for molecular structure prediction using IBM Cell Broadband Engine - an implementation perspective

    PubMed Central

    2010-01-01

    Background RNA structure prediction problem is a computationally complex task, especially with pseudo-knots. The problem is well-studied in existing literature and predominantly uses highly coupled Dynamic Programming (DP) solutions. The problem scale and complexity become embarrassingly humungous to handle as sequence size increases. This makes the case for parallelization. Parallelization can be achieved by way of networked platforms (clusters, grids, etc) as well as using modern day multi-core chips. Methods In this paper, we exploit the parallelism capabilities of the IBM Cell Broadband Engine to parallelize an existing Dynamic Programming (DP) algorithm for RNA secondary structure prediction. We design three different implementation strategies that exploit the inherent data, code and/or hybrid parallelism, referred to as C-Par, D-Par and H-Par, and analyze their performances. Our approach attempts to introduce parallelism in critical sections of the algorithm. We ran our experiments on SONY Play Station 3 (PS3), which is based on the IBM Cell chip. Results Our results suggest that introducing parallelism in DP algorithm allows it to easily handle longer sequences which otherwise would consume a large amount of time in single core computers. The results further demonstrate the speed-up gain achieved in exploiting the inherent parallelism in the problem and also elicits the advantages of using multi-core platforms towards designing more sophisticated methodologies for handling a fairly long sequence of RNA. Conclusion The speed-up performance reported here is promising, especially when sequence length is long. To the best of our literature survey, the work reported in this paper is probably the first-of-its-kind to utilize the IBM Cell Broadband Engine (a heterogeneous multi-core chip) to implement a DP. The results also encourage using multi-core platforms towards designing more sophisticated methodologies for handling a fairly long sequence of RNA to predict

  18. Amide group anchored glucose oxidase based anodic catalysts for high performance enzymatic biofuel cell

    NASA Astrophysics Data System (ADS)

    Chung, Yongjin; Ahn, Yeonjoo; Kim, Do-Heyoung; Kwon, Yongchai

    2017-01-01

    A new enzyme catalyst is formed by fabricating gold nano particle (GNP)-glucose oxidase (GOx) clusters that are then attached to polyethyleneimine (PEI) and carbon nanotube (CNT) with cross-linkable terephthalaldehyde (TPA) (TPA/[CNT/PEI/GOx-GNP]). Especially, amide bonds belonging to TPA play an anchor role for incorporating rigid bonding among GNP, GOx and CNT/PEI, while middle size GNP is well bonded with thiol group of GOx to form strong GNP-GOx cluster. Those bonds are identified by chemical and electrochemical characterizations like XPS and cyclic voltammogram. The anchording effect of amide bonds induces fast electron transfer and strong chemical bonding, resulting in enhancements in (i) catalytic activity, (ii) amount of immobilized GOx and (ii) performance of enzymatic biofuel cell (EBC) including the catalyst. Regarding the catalytic activity, the TPA/[CNT/PEI/GOx-GNP] produces high electron transfer rate constant (6 s-1), high glucose sensitivity (68 μA mM-1 cm-2), high maximum current density (113 μA cm-2), low charge transfer resistance (17.0 Ω cm2) and long-lasting durability while its chemical structure is characterized by XPS confirming large portion of amide bond. In EBC measurement, it has high maximum power density (0.94 mW cm-2) compatible with catalytic acitivity measurements.

  19. High shear enrichment improves the performance of the anodophilic microbial consortium in a microbial fuel cell

    PubMed Central

    Pham, Hai The; Boon, Nico; Aelterman, Peter; Clauwaert, Peter; De Schamphelaire, Liesje; Van Oostveldt, Patrick; Verbeken, Kim; Rabaey, Korneel; Verstraete, Willy

    2008-01-01

    Summary In many microbial bioreactors, high shear rates result in strong attachment of microbes and dense biofilms. In this study, high shear rates were applied to enrich an anodophilic microbial consortium in a microbial fuel cell (MFC). Enrichment at a shear rate of about 120 s−1 resulted in the production of a current and power output two to three times higher than those in the case of low shear rates (around 0.3 s−1). Biomass and biofilm analyses showed that the anodic biofilm from the MFC enriched under high shear rate conditions, in comparison with that under low shear rate conditions, had a doubled average thickness and the biomass density increased with a factor 5. The microbial community of the former, as analysed by DGGE, was significantly different from that of the latter. The results showed that enrichment by applying high shear rates in an MFC can result in a specific electrochemically active biofilm that is thicker and denser and attaches better, and hence has a better performance. PMID:21261869

  20. High performance anti-reflection coatings for broadband multi-junction solar cells

    SciTech Connect

    AIKEN,DANIEL J.

    2000-02-23

    The success of bandgap engineering has made high efficiency broadband multi-junction solar cells possible with photo-response out to the band edge of Ge. Modeling has been conducted which suggests that current double layer anti-reflection coating technology is not adequate for these devices in certain cases. Approaches for the development of higher performance anti-reflection coatings are examined. A new AR coating structure based on the use of Herpin equivalent layers is presented. Optical modeling suggests a decrease in the solar weighted reflectance of over 2.5{percent} absolute as a result. This structure requires no additional optical material development and characterization because no new optical materials are necessary. Experimental results and a sensitivity analysis are presented.

  1. Tropolone as a High-Performance Robust Anchoring Group for Dye-Sensitized Solar Cells.

    PubMed

    Higashino, Tomohiro; Fujimori, Yamato; Sugiura, Kenichi; Tsuji, Yukihiro; Ito, Seigo; Imahori, Hiroshi

    2015-07-27

    A tropolone group has been employed for the first time as an anchoring group for dye-sensitized solar cells (DSSCs). The DSSC based on a porphyrin, YD2-o-C8T, with a tropolone moiety exhibited a power-conversion efficiency of 7.7 %, which is only slightly lower than that observed for a reference porphyrin, YD2-o-C8, with a conventional carboxylic group. More importantly, YD2-o-C8T was found to be superior to YD2-o-C8 with respect to DSSC durability and binding ability to TiO2 . These results unambiguously demonstrate that tropolone is a highly promising dye-anchoring group for DSSCs in terms of device durability as well as photovoltaic performance.

  2. Study of relationships of material properties and high efficiency solar cell performance on material composition

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1983-01-01

    The performance improvements obtainable from extending the traditionally thin back-surface-field (BSF) layer deep into the base of silicon solar cells under terrestrial solar illumination (AM1) are analyzed. This extended BSF cell is also known as the back-drift-field cell. About 100 silicon cells were analyzed, each with a different emitter or base dopant impurity distribution whose selection was based on physically anticipated improvements. The four principal performance parameters (the open-circuit voltage, the short-circuit current, the fill factor, and the maximum efficiency) are computed using a FORTRAN program, called Circuit Technique for Semiconductor-device Analysis, CTSA, which numerically solves the six Shockley Equations under AM1 solar illumination at 88.92 mW/cm, at an optimum cell thickness of 50 um. The results show that very significant performance improvements can be realized by extending the BSF layer thickness from 2 um (18% efficiency) to 40 um (20% efficiency).

  3. Electrocatalytic performance of fuel cell reactions at low catalyst loading and high mass transport.

    PubMed

    Zalitis, Christopher M; Kramer, Denis; Kucernak, Anthony R

    2013-03-28

    An alternative approach to the rotating disk electrode (RDE) for characterising fuel cell electrocatalysts is presented. The approach combines high mass transport with a flat, uniform, and homogeneous catalyst deposition process, well suited for studying intrinsic catalyst properties at realistic operating conditions of a polymer electrolyte fuel cell (PEFC). Uniform catalyst layers were produced with loadings as low as 0.16 μgPt cm(-2) and thicknesses as low as 200 nm. Such ultra thin catalyst layers are considered advantageous to minimize internal resistances and mass transport limitations. Geometric current densities as high as 5.7 A cm(-2)Geo were experimentally achieved at a loading of 10.15 μgPt cm(-2) for the hydrogen oxidation reaction (HOR) at room temperature, which is three orders of magnitude higher than current densities achievable with the RDE. Modelling of the associated diffusion field suggests that such high performance is enabled by fast lateral diffusion within the electrode. The electrodes operate over a wide potential range with insignificant mass transport losses, allowing the study of the ORR at high overpotentials. Electrodes produced a specific current density of 31 ± 9 mA cm(-2)Spec at a potential of 0.65 V vs. RHE for the oxygen reduction reaction (ORR) and 600 ± 60 mA cm(-2)Spec for the peak potential of the HOR. The mass activity of a commercial 60 wt% Pt/C catalyst towards the ORR was found to exceed a range of literature PEFC mass activities across the entire potential range. The HOR also revealed fine structure in the limiting current range and an asymptotic current decay for potentials above 0.36 V. These characteristics are not visible with techniques limited by mass transport in aqueous media such as the RDE.

  4. Graphene Oxide Derivatives as Hole- and Electron-Extraction Layers for High-Performance Polymer Solar Cells

    DTIC Science & Technology

    2013-11-20

    Graphene oxide derivatives as hole- and electron- extraction layers for high-performance polymer solar cells Jun Liu,*a Michael Durstockb and Liming...oxide (GO) and its derivatives have been used as a new class of efficient hole- and electron-extraction materials in polymer solar cells (PSCs...new class of efficient hole- and electron-extraction materials in polymer solar cells (PSCs). Highly efficient and stable PSCs have been fabricated

  5. Double-resonance spectroscopy in Rubidium vapour-cells for high performance and miniature atomic clocks

    NASA Astrophysics Data System (ADS)

    Gharavipour, M.; Affolderbach, C.; Kang, S.; Mileti, G.

    2017-01-01

    We report our studies on using microwave-optical double-resonance (DR) spectroscopy for a high-performance Rb vapour-cell atomic clock in view of future industrial applications. The clock physics package is very compact with a total volume of only 0.8 dm3. It contains a recently in-house developed magnetron-type cavity and a Rb vapour cell. A homed-made frequency-stabilized laser system with an integrated acousto-optical-modulator (AOM) - for switching and controlling the light output power- is used as an optical source in a laser head (LH). The LH has the overall volume of 2.5 dm3 including the laser diode, optical elements, AOM and electronics. In our Rb atomic clock two schemes of continuous-wave DR and Ramsey-DR schemes are used, where the latter one strongly reduces the light-shift effect by separation of the interaction of light and microwave. Applications of the DR clock approach to more radically miniaturized atomic clocks are discussed.

  6. Alcohol-soluble Star-shaped Oligofluorenes as Interlayer for High Performance Polymer Solar Cells

    PubMed Central

    Zou, Yang; He, Zhicai; Zhao, Baofeng; Liu, Yuan; Yang, Chuluo; Wu, Hongbin; Cao, Yong

    2015-01-01

    Two star-shaped oligofluorenes with hexakis(fluoren-2-yl)benzene as core are designed and sythesized for interfacial materials in polymer solar cell. Diethanolamino groups are attached to the side chain of fluorene units for T0-OH and T1-OH to enable the alcohol solubility, and additional hydrophobic n-hexyl chains are also grafted on the increased fluorene arms for T1-OH. In conventional device with PCDTBT/PC71BM as active layer, a 50% enhanced PCE is obtained by incorporating T0-OH and T1-OH as the interlayer compared with device without interlayer. By optimizing the active material with PTB7 and with the inverted device structure, a maximum PCE of 9.30% is achieved, which is among the highest efficiencies for PTB7 based polymer solar cells. The work function of modified electrode, the surface morphology and the suraface properties are systematically studied. By modifying the structures of the star-shaped molecules, a balance between the hydrophobic and hydrophilic property is finely tuned, and thus facilitate the interlayer for high performance of PSCs. PMID:26612688

  7. Induced Crystallization of Perovskites by a Perylene Underlayer for High-Performance Solar Cells.

    PubMed

    Wang, Zhao-Kui; Gong, Xiu; Li, Meng; Hu, Yun; Wang, Jin-Miao; Ma, Heng; Liao, Liang-Sheng

    2016-05-24

    Perovskite crystallization and interface engineering are regarded as the most crucial factors in achieving high-performance planar heterojunction (PHJ) perovskite solar cells (PSCs). Herein, we demonstrate a thin perylene underlayer via a solution-processable method. By using branch-shaped perylene film as a seed-mediated underlayer, crystalline perovskites with fabric morphology can be formed, which allows for obvious improvement in absorption by a light scattering effect. With its deep highest occupied molecular orbital (HOMO) level, perylene also plays an important role in the energy-level tailoring of poly(3,4-ethylenedioxythiophene): poly(styrenesulphonate) ( PSS) and CH3NH3PbIxCl3-x. In addition, perylene and perovskites form a fully crystalline heterojunction, which is beneficial for minimizing the defect and trap densities. Due to these merits, a maximum power conversion efficiency of 17.06% with improved cell stability is achieved. The finding in this work provides a simple route to control perovskite crystallizaition and to optimize the interfaces in PHJ PSCs simultaneously.

  8. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    SciTech Connect

    Jie Guan; Nguyen Minh

    2003-12-01

    This report summarizes the results of the work conducted under the program: ''Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells'' under contract number DE-AC26-00NT40711. The program goal is to advance materials and processes that can be used to produce economical, high-performance solid oxide fuel cells (SOFC) capable of achieving extraordinary high power densities at reduced temperatures. Under this program, anode-supported thin electrolyte based on lanthanum gallate (LSMGF) has been developed using tape-calendering process. The fabrication parameters such as raw materials characteristics, tape formulations and sintering conditions have been evaluated. Dense anode supported LSGMF electrolytes with thickness range of 10-50 micron have been fabricated. High performance cathode based on Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} (SSC) has been developed. Polarization of {approx}0.23 ohm-cm{sup 2} has been achieved at 600 C with Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3}cathode. The high-performance SSC cathode and thin gallate electrolyte have been integrated into single cells and cell performance has been characterized. Tested cells to date generally showed low performance because of low cell OCVs and material interactions between NiO in the anode and lanthanum gallate electrolyte.

  9. A high-performance solid oxide fuel cell anode based on lanthanum strontium vanadate

    NASA Astrophysics Data System (ADS)

    Park, Jong-Sung; Hasson, Ian D.; Gross, Michael D.; Chen, Chen; Vohs, J. M.; Gorte, R. J.

    Ceramic composites were prepared by infiltration of La 0.7Sr 0.3VO 3.85 (LSV) into porous scaffolds of yttria-stabilized zirconia (YSZ) and tested for use as solid oxide fuel cell (SOFC) anodes. There was no evidence for solid-state reaction between LSV and YSZ at calcination temperatures up to 1273 K. For calcination at 973 K, LSV formed a continuous film over the YSZ. The LSV phase reduced easily upon heating in H 2 to 973 K, with the reduction forming pores in the LSV and greatly increasing its surface area. The electrodes showed high electronic conductivity after reduction, with a 10-vol% LSV-YSZ composite exhibiting a conductivity of 2 S cm -1 at 973 K. In the absence of an added catalyst, the LSV-YSZ electrodes showed relatively poor performance; however, an electrode impedance of approximately 0.1 Ω cm 2 was achieved at 973 K in humidified H 2 following addition of 0.5 vol% Pd and 2.8 vol% ceria The LSV-YSZ composites were stable in CH 4 but there was evidence for poisoning of the Pd catalyst by V following high-temperature oxidation.

  10. Preparation and properties of high performance nanocomposite proton exchange membrane for fuel cell

    NASA Astrophysics Data System (ADS)

    Lin, Yu-Feng; Yen, Chuan-Yu; Ma, Chen-Chi M.; Liao, Shu-Hang; Hung, Chih-Hung; Hsiao, Yi-Hsiu

    Various spatially enlarged organoclays were prepared by using poly(oxyproplene)-backboned quaternary ammonium salts of various molecular weights M w 230, 400 and 2000 as the intercalating agents for Na +-montmorillonite. The modified MMT was utilized to improve the compatibility with Nafion ®. Sufficient interaction of the modified MMT with Nafion ® was studied by using X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS). The performance of the Nafion ®/ m-MMT composite membranes for direct methanol fuel cell (DMFCs) was evaluated in terms of water uptake, ion exchange capacity (IEC), methanol permeability, proton conductivity, and cell performance. The methanol permeability of the composite membrane decreased with the increasing of m-MMT content. The proton conductivity of the membrane was lowered slightly from that of pristine Nafion ® membrane. These results led to an essential improvement in the single-cell performance of DMFCs.

  11. High Performance Microbial Fuel Cells and Supercapacitors Using Micro-Electro-Mechanical System (MEMS) Technology

    NASA Astrophysics Data System (ADS)

    Ren, Hao

    A Microbial fuel cell (MFC) is a bio-inspired carbon-neutral, renewable electrochemical converter to extract electricity from catabolic reaction of micro-organisms. It is a promising technology capable of directly converting the abundant biomass on the planet into electricity and potentially alleviate the emerging global warming and energy crisis. The current and power density of MFCs are low compared with conventional energy conversion techniques. Since its debut in 2002, many studies have been performed by adopting a variety of new configurations and structures to improve the power density. The reported maximum areal and volumetric power densities range from 19 mW/m2 to 1.57 W/m2 and from 6.3 W/m3 to 392 W/m 3, respectively, which are still low compared with conventional energy conversion techniques. In this dissertation, the impact of scaling effect on the performance of MFCs are investigated, and it is found that by scaling down the characteristic length of MFCs, the surface area to volume ratio increases and the current and power density improves. As a result, a miniaturized MFC fabricated by Micro-Electro-Mechanical System (MEMS) technology with gold anode is presented in this dissertation, which demonstrate a high power density of 3300 W/m3. The performance of the MEMS MFC is further improved by adopting anodes with higher surface area to volume ratio, such as carbon nanotube (CNT) and graphene based anodes, and the maximum power density is further improved to a record high power density of 11220 W/m3. A novel supercapacitor by regulating the respiration of the bacteria is also presented, and a high power density of 531.2 A/m2 (1,060,000 A/m3) and 197.5 W/m2 (395,000 W/m3), respectively, are marked, which are one to two orders of magnitude higher than any previously reported microbial electrochemical techniques.

  12. High performance metal-supported solid oxide fuel cells with Gd-doped ceria barrier layers

    NASA Astrophysics Data System (ADS)

    Klemensø, Trine; Nielsen, Jimmi; Blennow, Peter; Persson, Åsa H.; Stegk, Tobias; Christensen, Bjarke Holl; Sønderby, Steffen

    Metal-supported solid oxide fuel cells are believed to have commercial advantages compared to conventional anode (Ni-YSZ) supported cells, with the metal-supported cells having lower material costs, increased tolerance to mechanical and thermal stresses, and lower operational temperatures. The implementation of a metallic support has been challenged by the need to revise the cell fabrication route, as well as electrode microstructures and material choices, to compete with the energy output and stability of full ceramic cells. The metal-supported SOFC design developed at Risø DTU has been improved, and an electrochemical performance beyond the state-of-the-art anode-supported SOFC is demonstrated possible, by introducing a CGO barrier layer in combination with Sr-doped lanthanum cobalt oxide (LSC) cathode. Area specific resistances (ASR) down to 0.27 Ω cm 2, corresponding to a maximum power density of 1.14 W cm -2 at 650 °C and 0.6 V, were obtained on cells with barrier layers fabricated by magnetron sputtering. The performance is dependent on the density of the barrier layer, indicating Sr 2+ diffusion is occurring at the intermediate SOFC temperatures. The optimized design further demonstrate improved durability with steady degradation rates of 0.9% kh -1 in cell voltage for up to 3000 h galvanostatic testing at 650 °C and 0.25 A cm -2.

  13. Understanding the Effects of a High Surface Area Nanostructured ITO Electrode on Organic Solar Cell Performance.

    PubMed

    Cao, Bing; He, Xiaoming; Sorge, Jason; Lalany, Abeed; Ahadi, Kaveh; Afshar, Amir; Olsen, Brian C; Hauger, Tate C; Mobarok, Md Hosnay; Li, Peng; Cadien, Kenneth C; Brett, Michael J; Luber, Erik J; Buriak, Jillian M

    2017-10-12

    Organic solar cells (OSCs) are a complex assembly of disparate materials, each with a precise function within the device. Typically, the electrodes are flat, and the device is fabricated through a layering approach of the interfacial layers and photoactive materials. This work explores the integration of high surface area transparent electrodes to investigate the possible role(s) a three-dimensional electrode could take within an OSC, with a BHJ composed of a donor-acceptor combination with a high degree of electron and hole mobility mismatch. Nanotree indium tin oxide (ITO) electrodes were prepared via glancing angle deposition (GLAD), structures that were previously demonstrated to be single-crystalline. A thin layer of zinc oxide was deposited on the ITO nanotrees via atomic layer deposition (ALD), followed by a self-assembled monolayer of C60-based molecules that was bound to the zinc oxide surface through a carboxylic acid group. Infiltration of these functionalized ITO nanotrees with the photoactive layer, the bulk heterojunction (BHJ) comprising PC71BM and a high hole mobility low band gap polymer (PDPPTT-T-TT), led to families of devices that were analyzed for the effect of nanotree height. When the height was varied from 0, to 50 nm, 75 nm, 100, and 120 nm, statistically significant differences of device performance were noted, with the maximum device efficiencies observed with a nanotree height of 75 nm. From analysis of these results, it was found that the intrinsic mobility mismatch between the donor and acceptor phases could be compensated for when the electron collection length was reduced relative to the hole collection length, resulting in more balanced charge extraction, reduced recombination, leading to improved efficiencies. However, as the ITO nanotrees increased in height and branching, the decrease in electron collection length was offset by an increase in hole collection length and potential deleterious electric field redistribution effects

  14. Chlorination of low-band-gap polymers: Toward high-performance polymer solar cells

    DOE PAGES

    Mo, Daize; Wang, Huan; Chen, Hui; ...

    2017-03-08

    Here, halogenation is an effective way to tune the energy levels of organic semiconducting materials. To date, fluorination of organic semiconducting materials to fabricate polymer solar cells (PSCs) has been used far more than chlorination; however, fluorine exchange reactions suffer from low yields and the resulting fluorinated polymer always comes with higher price, which will greatly hinder their commercial applications. Herein, we designed and synthesized a series of chlorinated donor-acceptor (D-A) type polymers, in which benzo[1,2-b:4,5- b]dithiophene and chlorinated benzothiadiazole units are connected by thiophene π-bridges with an asymmetric alkyl chain. These chlorinated polymers showed deep highest occupied molecular orbitalmore » energy levels, which promoted the efficiency of their corresponding PSCs by increasing the device open circuit voltage. The asymmetric alkyl chain on the thiophene moieties gave the final polymer sufficient solubility for solution processing and strong π-π stacking in films allowed for high mobility. Although the introduction of a large chlorine atom increased the torsion angle of the polymer backbone, the chlorinated polymers maintained high crystallinity and a favorable backbone orientation in the blended films. These factors contributed to respectable device performances from thick-film devices, which showed PCEs as high as 9.11% for a 250 nm-thick active layer. These results demonstrate that chlorination is a promising method to fine tune the energy levels of conjugated polymers, and chlorinated benzothiadiazole may be a versatile building block in materials for efficient solar energy conversion.« less

  15. Thermal abuse performance of high-power 18650 Li-ion cells

    NASA Astrophysics Data System (ADS)

    Roth, E. P.; Doughty, D. H.

    High-power 18650 Li-ion cells have been developed for hybrid electric vehicle applications as part of the DOE Advanced Technology Development (ATD) program. The thermal abuse response of two advanced chemistries (Gen1 and Gen2) were measured and compared with commercial Sony 18650 cells. Gen1 cells consisted of an MCMB graphite based anode and a LiNi 0.85Co 0.15O 2 cathode material while the Gen2 cells consisted of a MAG10 anode graphite and a LiNi 0.80Co 0.15 Al 0.05O 2 cathode. Accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC) were used to measure the thermal response and properties of the cells and cell materials up to 400 °C. The MCMB graphite was found to result in increased thermal stability of the cells due to more effective solid electrolyte interface (SEI) formation. The Al stabilized cathodes were seen to have higher peak reaction temperatures that also gave improved cell thermal response. The effects of accelerated aging on cell properties were also determined. Aging resulted in improved cell thermal stability with the anodes showing a rapid reduction in exothermic reactions while the cathodes only showed reduced reactions after more extended aging.

  16. Molecular helices as electron acceptors in high-performance bulk heterojunction solar cells

    PubMed Central

    Zhong, Yu; Trinh, M. Tuan; Chen, Rongsheng; Purdum, Geoffrey E.; Khlyabich, Petr P.; Sezen, Melda; Oh, Seokjoon; Zhu, Haiming; Fowler, Brandon; Zhang, Boyuan; Wang, Wei; Nam, Chang-Yong; Sfeir, Matthew Y.; Black, Charles T.; Steigerwald, Michael L.; Loo, Yueh-Lin; Ng, Fay; Zhu, X.-Y.; Nuckolls, Colin

    2015-01-01

    Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor−acceptor interfaces. Atomic force microscopy reveals a mesh-like network of acceptors with pores that are tens of nanometres in diameter for efficient exciton separation and charge transport. This study describes a new motif for designing highly efficient acceptors for organic solar cells. PMID:26382113

  17. Molecular helices as electron acceptors in high-performance bulk heterojunction solar cells

    DOE PAGES

    Yu M. Zhong; Nam, Chang -Yong; Trinh, M. Tuan; ...

    2015-09-18

    Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealedmore » both electron and hole transfer processes at the donor–acceptor interfaces. Atomic force microscopy reveals a mesh-like network of acceptors with pores that are tens of nanometres in diameter for efficient exciton separation and charge transport. As a result, this study describes a new motif for designing highly efficient acceptors for organic solar cells.« less

  18. Molecular helices as electron acceptors in high-performance bulk heterojunction solar cells.

    PubMed

    Zhong, Yu; Trinh, M Tuan; Chen, Rongsheng; Purdum, Geoffrey E; Khlyabich, Petr P; Sezen, Melda; Oh, Seokjoon; Zhu, Haiming; Fowler, Brandon; Zhang, Boyuan; Wang, Wei; Nam, Chang-Yong; Sfeir, Matthew Y; Black, Charles T; Steigerwald, Michael L; Loo, Yueh-Lin; Ng, Fay; Zhu, X-Y; Nuckolls, Colin

    2015-09-18

    Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor-acceptor interfaces. Atomic force microscopy reveals a mesh-like network of acceptors with pores that are tens of nanometres in diameter for efficient exciton separation and charge transport. This study describes a new motif for designing highly efficient acceptors for organic solar cells.

  19. Molecular helices as electron acceptors in high-performance bulk heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Zhong, Yu; Trinh, M. Tuan; Chen, Rongsheng; Purdum, Geoffrey E.; Khlyabich, Petr P.; Sezen, Melda; Oh, Seokjoon; Zhu, Haiming; Fowler, Brandon; Zhang, Boyuan; Wang, Wei; Nam, Chang-Yong; Sfeir, Matthew Y.; Black, Charles T.; Steigerwald, Michael L.; Loo, Yueh-Lin; Ng, Fay; Zhu, X.-Y.; Nuckolls, Colin

    2015-09-01

    Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor-acceptor interfaces. Atomic force microscopy reveals a mesh-like network of acceptors with pores that are tens of nanometres in diameter for efficient exciton separation and charge transport. This study describes a new motif for designing highly efficient acceptors for organic solar cells.

  20. Molecular helices as electron acceptors in high-performance bulk heterojunction solar cells

    SciTech Connect

    Yu M. Zhong; Nam, Chang -Yong; Trinh, M. Tuan; Chen, Rongsheng; Purdum, Geoffrey E.; Khlyabich, Petr P.; Sezen, Melda; Oh, Seokjoon; Zhu, Haiming; Fowler, Brandon; Zhang, Boyuan; Wang, Wei; Sfeir, Matthew Y.; Black, Charles T.; Steigerwald, Michael L.; Loo, Yueh -Lin; Ng, Fay; Zhu, X. -Y.; Nuckolls, Colin

    2015-09-18

    Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor–acceptor interfaces. Atomic force microscopy reveals a mesh-like network of acceptors with pores that are tens of nanometres in diameter for efficient exciton separation and charge transport. As a result, this study describes a new motif for designing highly efficient acceptors for organic solar cells.

  1. Interface Engineering through Atomic Layer Deposition towards Highly Improved Performance of Dye-Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Lu, Hao; Tian, Wei; Guo, Jun; Li, Liang

    2015-08-01

    A composite photoanode comprising ultralong ZnO nanobelts and TiO2 nanoparticles was prepared and its performance in dye-sensitized solar cells (DSSCs) was optimized and compared to the photoanode consisting of conventional TiO2 nanoparticles. The ultralong ZnO nanobelts were synthesized in high yield by a facile solution approach at 90 oC followed by annealing at 500 oC. The effect of the ratio of ZnO nanobelts to TiO2 nanoparticles on the light scattering, specific surface area, and interface recombination were investigated. An optimum amount of ZnO nanobelts enhanced the photon-conversion efficiency by 61.4% compared to that of the conventional TiO2 nanoparticles. To further reduce the recombination rate and increase the carrier lifetime, Atomic Layer Deposition (ALD) technique was utilized to coat a continuous TiO2 film surrounding the ZnO nanobelts and TiO2 nanoparticles, functioning as a barrier-free access of all electrons to conductive electrodes. This ALD treatment improved the interface contact within the whole photoanode system, finally leading to significant enhancement (137%) in the conversion efficiency of DSSCs.

  2. Ni3Mo3C as anode catalyst for high-performance microbial fuel cells.

    PubMed

    Zeng, Li-Zhen; Zhao, Shao-Fei; Li, Wei-Shan

    2015-03-01

    Ni3Mo3C was prepared by a modified organic colloid method and explored as anode catalyst for high-performance microbial fuel cell (MFC) based on Klebsiella pneumoniae (K. pneumoniae). The prepared sample was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET). The activity of the sample as anode catalyst for MFC based on K. pneumoniae was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and polarization curve measurement. The results show that the adding of nickel in Mo2C increases the BET surface area of Mo2C and improves the electrocatalytic activity of Mo2C towards the oxidation of microbial fermentation products. The power density of MFC with 3 mg cm(-2) Ni3Mo3C anode is far higher than that of the MFC with carbon felt as anode without any catalyst, which is 19 % higher than that of Mo2C anode and produced 62 % as much as that of Pt anode, indicating that Ni3Mo3C is comparative to noble metal platinum as anode electrocatalyst for MFCs by increasing the loading.

  3. High-performance liquid chromatographic assay of human red blood cell thiopurine methyltransferase activity.

    PubMed

    Lennard, L; Singleton, H J

    1994-11-04

    An assay is described for the determination of red blood cell (RBC) thiopurine methyltransferase (TPMT) activity. TPMT S-methylates the antileukaemic drugs 6-mercaptopurine (6-MP) and 6-thioguanine and enzyme activity is inherited as a genetic trait. The assay is based on the TPMT-catalysed conversion of 6-MP to 6-methylmercaptopurine (methyl-MP) with non-radioactive S-adenosyl-L-methionine as the methyl donor. The methyl-MP metabolite is extracted into toluene as a phenyl-mercury adduct and back-extracted into 0.1 M HCl. Methyl-MP is quantitated by reversed-phase high-performance liquid chromatography (HPLC) with ultraviolet detection using a C18 Resolve cartridge and a mobile phase of methanol-water (20:80, v/v) with 100 mM triethylamine adjusted to pH 3.2 with orthophosphoric acid. There was a strong correlation between the HPLC assay and the established radiochemical assay (P < 0.0001). TPMT activities were measured by both methods in a population study of 111 children. There was no significant difference between the two frequency distribution histograms (P > 0.6).

  4. Interface Engineering through Atomic Layer Deposition towards Highly Improved Performance of Dye-Sensitized Solar Cells

    PubMed Central

    Lu, Hao; Tian, Wei; Guo, Jun; Li, Liang

    2015-01-01

    A composite photoanode comprising ultralong ZnO nanobelts and TiO2 nanoparticles was prepared and its performance in dye-sensitized solar cells (DSSCs) was optimized and compared to the photoanode consisting of conventional TiO2 nanoparticles. The ultralong ZnO nanobelts were synthesized in high yield by a facile solution approach at 90 oC followed by annealing at 500 oC. The effect of the ratio of ZnO nanobelts to TiO2 nanoparticles on the light scattering, specific surface area, and interface recombination were investigated. An optimum amount of ZnO nanobelts enhanced the photon-conversion efficiency by 61.4% compared to that of the conventional TiO2 nanoparticles. To further reduce the recombination rate and increase the carrier lifetime, Atomic Layer Deposition (ALD) technique was utilized to coat a continuous TiO2 film surrounding the ZnO nanobelts and TiO2 nanoparticles, functioning as a barrier-free access of all electrons to conductive electrodes. This ALD treatment improved the interface contact within the whole photoanode system, finally leading to significant enhancement (137%) in the conversion efficiency of DSSCs. PMID:26238737

  5. A High Performance H2-Cl2 Fuel Cell for Space Power Applications

    NASA Technical Reports Server (NTRS)

    Anderson, Everett B.; Taylor, E. Jennings; Wilemski, Gerald; Gelb, Alan

    1993-01-01

    NASA has numerous airborne/spaceborne applications for which high power and energy density power sources are needed. The proton exchange membrane fuel cell (PEMFC) is an attractive candidate for such a power source. PEMFC's offer many advantages for airborne/spaceborne applications. They have high power and energy densities, convert fuel to electrical power with high efficiency at both part and full load, and can rapidly startup and shutdown. In addition, PEMFC's are lightweight and operate silently. A significant impediment to the attainment of very high power and energy densities by PEMFC's is their current exclusive reliance on oxygen as the oxidant. Conventional PEMFC's oxidize hydrogen at the anode and reduce oxygen at the cathode. The electrode kinetics of oxygen reduction are known to be highly irreversible, incurring large overpotential losses. In addition, the modest open circuit potential of 1.2V for the H2-O2 fuel cell is unattainable due to mixed potential effects at the oxygen electrode. Because of the high overpotential losses, cells using H2 and O2 are capable of achieving high current densities only at very low cell voltages, greatly curtailing their power output. Based on experimental work on chlorine reduction in a gas diffusion electrode, we believe significant increases in both the energy and power densities of PEMFC systems can be achieved by employing chlorine as an alternative oxidant.

  6. High performance radiation-grafted membranes and electrodes for polymer electrolyte fuel cells

    SciTech Connect

    Nezu, Shinji; Seko, Hideo; Gondo, Masaki; Ito, Naoki

    1996-12-31

    Polymer electrolyte fuel cells (PEFC) have attracted much attention for stationary and electric vehicle applications. Much progress has been made to improve their performance recently. However there are still several problems to overcome for commercialization. Among them, the cost of polymer electrolyte membranes seems to be rather critical, because a cost estimate of a practical fuel cell stack shows that the membrane cost must be reduced at least by two orders of magnitude based on current perfluorosulfonic acid membranes eg. Nafion{reg_sign}. Thus the development of new membrane materials is strongly desired. Styrene grafted tetrafluoroethylene-hexafluoropropylene copolymer (FEP) membranes have been studied for a fuel cell application by G. Scherer et al. These authors showed that membranes obtained by radiation grafting served as an alternative membrane for fuel cells although there were several problems to overcome in the future. These problems include shorter life time which was concluded to result from the decomposition of grafted polystyrene side chains. We report here the performance of our fuel cells which were fabricated from our radiation grafted membranes (IMRA MEMBRANE) and gas diffusion electrodes.

  7. Toward performance-diverse small-molecule libraries for cell-based phenotypic screening using multiplexed high-dimensional profiling

    PubMed Central

    Wawer, Mathias J.; Li, Kejie; Gustafsdottir, Sigrun M.; Ljosa, Vebjorn; Bodycombe, Nicole E.; Marton, Melissa A.; Sokolnicki, Katherine L.; Bray, Mark-Anthony; Kemp, Melissa M.; Winchester, Ellen; Taylor, Bradley; Grant, George B.; Hon, C. Suk-Yee; Duvall, Jeremy R.; Wilson, J. Anthony; Bittker, Joshua A.; Dančík, Vlado; Narayan, Rajiv; Subramanian, Aravind; Winckler, Wendy; Golub, Todd R.; Carpenter, Anne E.; Shamji, Alykhan F.; Schreiber, Stuart L.; Clemons, Paul A.

    2014-01-01

    High-throughput screening has become a mainstay of small-molecule probe and early drug discovery. The question of how to build and evolve efficient screening collections systematically for cell-based and biochemical screening is still unresolved. It is often assumed that chemical structure diversity leads to diverse biological performance of a library. Here, we confirm earlier results showing that this inference is not always valid and suggest instead using biological measurement diversity derived from multiplexed profiling in the construction of libraries with diverse assay performance patterns for cell-based screens. Rather than using results from tens or hundreds of completed assays, which is resource intensive and not easily extensible, we use high-dimensional image-based cell morphology and gene expression profiles. We piloted this approach using over 30,000 compounds. We show that small-molecule profiling can be used to select compound sets with high rates of activity and diverse biological performance. PMID:25024206

  8. High performance dye-sensitized solar cell based on hydrothermally deposited multiwall carbon nanotube counter electrode

    NASA Astrophysics Data System (ADS)

    Siriroj, Sumeth; Pimanpang, Samuk; Towannang, Madsakorn; Maiaugree, Wasan; Phumying, Santi; Jarernboon, Wirat; Amornkitbamrung, Vittaya

    2012-06-01

    Conductive glass was coated with multiwall carbon nanotubes (MWCNTs) by a hydrothermal method. MWCNTs films were subsequently used as dye-sensitized solar cell (DSSC) counter electrodes. The performance of hydrothermal MWCNT DSSC was ˜2.37%. After film annealing in an Ar atmosphere, annealed-hydrothermal MWCNT (AHT-CNT) DSSC efficiency was significantly increased to ˜7.66%, in comparison to ˜8.01% for sputtered-Pt DSSC. Improvement of AHT-CNT DSSC performance is attributed to a decrease in charge-transfer resistance from 1500 Ω to 30 Ω as observed by electrochemical impedance spectroscopy.

  9. High-performance porous silicon solar cell development. Final report, October 1, 1993--September 30, 1995

    SciTech Connect

    Maruska, P

    1996-09-01

    The goal of the program was to demonstrate use of porous silicon in new solar cell structures. Porous silicon technology has been developed at Spire for producing visible light-emitting diodes (LEDs). The major aspects that they have demonstrated are the following: porous silicon active layers have been made to show photovoltaic action; porous silicon surface layers can act as antireflection coatings to improve the performance of single-crystal silicon solar cells; and porous silicon surface layers can act as antireflection coatings on polycrystalline silicon solar cells. One problem with the use of porous silicon is to achieve good lateral conduction of electrons and holes through the material. This shows up in terms of poor blue response and photocurrents which increase with increasing reverse bias applied to the diode.

  10. Morphology evolution in high-performance polymer solar cells processed from nonhalogenated solvent

    SciTech Connect

    Cai, Wanzhu; Liu, Peng; Jin, Yaocheng; Xue, Qifan; Liu, Feng; Russell, Thomas P.; Huang, Fei; Yip, Hin -Lap; Cao, Yong

    2015-05-26

    A new processing protocol based on non-halogenated solvent and additive is developed to produce polymer solar cells with power conversion efficiencies better than those processed from commonly used halogenated solvent-additive pair. Morphology studies show that good performance correlates with a finely distributed nanomorphology with a well-defined polymer fibril network structure, which leads to balanced charge transport in device operation.

  11. Non-basic high-performance molecules for solution-processed organic solar cells.

    PubMed

    van der Poll, Thomas S; Love, John A; Nguyen, Thuc-Quyen; Bazan, Guillermo C

    2012-07-17

    A new small molecule, p-DTS(FBTTh(2))(2), is designed for incorporation into solution-fabricated high-efficiency organic solar cells. Of primary importance is the incorporation of electron poor heterocycles that are not prone to protonation and thereby enable the incorporation of commonly used interlayers between the organic semiconductor and the charge collecting electrodes. These features have led to the creation of p-DTS(FBTTh(2))(2)/PC(71)BM solar cells with power conversion efficiencies of up to 7%.

  12. High-Performance Fully Printable Perovskite Solar Cells via Blade-Coating Technique under the Ambient Condition

    SciTech Connect

    Yang, Zhibin; Chueh, Chu-Chen; Zuo, Fan; Kim, Jong H.; Liang, Po-Wei; Jen, Alex K. -Y.

    2015-04-30

    A fully printable perovskite solar cell (PVSC) is demonstrated using a blade-coating technique under ambient conditions with controlled humidity. The influence of humidity on perovskite's crystallization is systematically investigated to realize the ambient processing condition. A high power conversion efficiency of 10.44% is achieved after optimizing the blade-coating process and, more importantly, a high-performance flexible PVSC is demonstrated for the first time. A high efficiency of 7.14% is achieved.

  13. High-performance imaging of stem cells using single-photon emissions

    NASA Astrophysics Data System (ADS)

    Wagenaar, Douglas J.; Moats, Rex A.; Hartsough, Neal E.; Meier, Dirk; Hugg, James W.; Yang, Tang; Gazit, Dan; Pelled, Gadi; Patt, Bradley E.

    2011-10-01

    Radiolabeled cells have been imaged for decades in the field of autoradiography. Recent advances in detector and microelectronics technologies have enabled the new field of "digital autoradiography" which remains limited to ex vivo specimens of thin tissue slices. The 3D field-of-view (FOV) of single cell imaging can be extended to millimeters if the low energy (10-30 keV) photon emissions of radionuclides are used for single-photon nuclear imaging. This new microscope uses a coded aperture foil made of highly attenuating elements such as gold or platinum to form the image as a kind of "lens". The detectors used for single-photon emission microscopy are typically silicon detectors with a pixel pitch less than 60 μm. The goal of this work is to image radiolabeled mesenchymal stem cells in vivo in an animal model of tendon repair processes. Single-photon nuclear imaging is an attractive modality for translational medicine since the labeled cells can be imaged simultaneously with the reparative processes by using the dual-isotope imaging technique. The details our microscope's two-layer gold aperture and the operation of the energy-dispersive, pixellated silicon detector are presented along with the first demonstration of energy discrimination with a 57Co source. Cell labeling techniques have been augmented by genetic engineering with the sodium-iodide symporter, a type of reporter gene imaging method that enables in vivo uptake of free 99mTc or an iodine isotope at a time point days or weeks after the insertion of the genetically modified stem cells into the animal model. This microscopy work in animal research may expand to the imaging of reporter-enabled stem cells simultaneously with the expected biological repair process in human clinical trials of stem cell therapies.

  14. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    SciTech Connect

    Jie Guan; Atul Verma; Nguyen Minh

    2003-04-01

    This document summarizes the technical progress from September 2002 to March 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. The causes have been identified for the unstable open circuit voltage (OCV) and low performance exhibited by the anode-supported lanthanum gallate based cells from the earlier development. Promising results have been obtained in the area of synthesis of electrolyte and cathode powders, which showed excellent sintering and densification at low temperatures. The fabrication of cells using tapecalendering process for anode-supported thin lanthanum gallate electrolyte cells and their performance optimization is in progress.

  15. Manipulating Water in High-Performance Hydroxide Exchange Membrane Fuel Cells through Asymmetric Humidification and Wetproofing

    SciTech Connect

    Kaspar, RB; Letterio, MP; Wittkopf, JA; Gong, K; Gu, S; Yan, YS

    2015-02-18

    Hydroxide exchange membrane fuel cells (HEMFCs) are an emerging low-cost alternative to conventional proton exchange membrane fuel cells. In addition to producing water at the anode, HEMFCs consume water at the cathode, leading to distinctive water transport behavior. We report that gas diffusion layer (GDL) wetproofing strictly lowers cell performance, but that the penalty is much higher when the anode side is wetproofed compared to the cathode side. We attribute this penalty primarily to mass transport losses from anode flooding, suggesting that cathode humidification may be more beneficial than anode humidification for this device. GDLs with little or no wetproofing perform best, yielding a competitive peak power density of 737 mW cm(-2). (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, hup://creativecommons.orgilicenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.

  16. Research of silicon solar cells' performance after being irradiated by high power laser

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Li, Yunfei; Li, Yanjie; Zhao, Guomin; Chen, Minsun

    2016-11-01

    Compared with traditional methods of energy supply, there is a great possibility to get a more remarkable enhancement of conversion efficiency for laser power (of proper wavelength and intensity) beaming to silicon solar cells. However, it should be noticed that cells may be damaged by high power laser. Based on the background, this essay explores high-power-laser's possible damage to silicon solar cells by analyzing IV curves (obtained by IV tester) and minority-carrier lifetime (measured by open-circuit-voltage-decay method). Research shows that, for 30s irradiation, minority-carrier lifetime decreases to some extent when irradiated by laser of over 5.5W/cm2 and the higher laser power density, the more degradation. Similarly, IV curves see a downward trend under laser of over 5.5W/cm2. In addition, there is a roughly linear relationship between lifetime and the decrease amount of short circuit current. Moreover, the degradation degree has a close relation with the maximum temperature. The prolonged illumination would not bring about more serious damage if one cell had already reached an equilibrium temperature.

  17. Graphene/carbon cloth anode for high-performance mediatorless microbial fuel cells.

    PubMed

    Liu, Jing; Qiao, Yan; Guo, Chun Xian; Lim, Sierin; Song, Hao; Li, Chang Ming

    2012-06-01

    Graphene was electrochemically deposited on carbon cloth to fabricate an anode for a Pseudomonas aeruginosa mediatorless microbial fuel cell (MFC). The graphene modification improved power density and energy conversion efficiency by 2.7 and 3 times, respectively. The improvement is attributed to the high biocompatibility of graphene which promotes bacteria growth on the electrode surface that results in the creation of more direct electron transfer activation centers and stimulates excretion of mediating molecules for higher electron transfer rate. A parallel bioelectrocatalytic mechanism consisting of simultaneous direct electron transfer and cell-excreted mediator-enabled electron transfer was established in the P. aeruginosa-catalyzed MFC. This study does not only offer fundamental insights into MFC reactions, but also suggests a low cost manufacturing process to fabricate high power MFCs for practical applications.

  18. A high-performance aluminum-feed microfluidic fuel cell stack

    NASA Astrophysics Data System (ADS)

    Wang, Yifei; Leung, Dennis Y. C.

    2016-12-01

    In this paper, a six-cell microfluidic fuel cell (MFC) stack is demonstrated. Low-cost aluminum is fed directly to the stack, which produces hydrogen fuel on site, through the Al-H2O reaction. This design is not only cost-efficient, but also eliminates the need for hydrogen storage. Unlike the conventional MFC stacks which generally require complex electrolyte distribution and management, the present Al-feed MFC stack requires only a single electrolyte stream, flowing successively through individual cells, which is finally utilized for hydrogen generation. In this manner, the whole system is greatly simplified while the operational robustness is also improved. With 2 M sodium hydroxide solution as electrolyte and kitchen foil Al as fuel, the present six-cell stack (in series) exhibits an open circuit voltage of nearly 6 V and a peak power density of 180.6 mWcm-2 at room temperature. In addition, an energy density of 1 Whg-1(Al) is achieved, which is quite high and comparable with its proton exchange membrane-based counterparts. Finally, pumpless operation of the present stack, together with its practical applications are successfully demonstrated, including lightening LED lights, driving an electric fan, and cell phone charging.

  19. Defect Engineering, Cell Processing, and Modeling for High-Performance, Low-Cost Crystalline Silicon Photovoltaics

    SciTech Connect

    Buonassisi, Tonio

    2013-02-26

    The objective of this project is to close the efficiency gap between industrial multicrystalline silicon (mc-Si) and monocrystalline silicon solar cells, while preserving the economic advantage of low-cost, high-volume substrates inherent to mc-Si. Over the course of this project, we made significant progress toward this goal, as evidenced by the evolution in solar-cell efficiencies. While most of the benefits of university projects are diffuse in nature, several unique contributions can be traced to this project, including the development of novel characterization methods, defect-simulation tools, and novel solar-cell processing approaches mitigate the effects of iron impurities ("Impurities to Efficiency" simulator) and dislocations. In collaboration with our industrial partners, this project contributed to the development of cell processing recipes, specialty materials, and equipment that increased cell efficiencies overall (not just multicrystalline silicon). Additionally, several students and postdocs who were either partially or fully engaged in this project (as evidenced by the publication record) are currently in the PV industry, with others to follow.

  20. The effect of minority carrier mobility variations on the performance of high voltage silicon solar cells

    NASA Technical Reports Server (NTRS)

    Weizer, V. G.; Godlewski, M. P.

    1980-01-01

    A multistep diffusion processing schedule is described which allows the attainment of high open circuit voltages in 0.1 ohm/cm silicon cells. The schedule consists of a deep primary diffusion, followed by an acid etch of emmitter surface which is then followed by a shallow secondary diffusion. A correlation is made between the observed voltage increases and the time of primary diffusion. Results indicate that as the primary diffusion time increases, the voltage rises monotonically.

  1. Design of Radial pin Si Nanowires for High Performance Solar Cells

    SciTech Connect

    Nguyen, Binh-Minh; Yoo, Jinkyoung; Dayeh, Shadi; Picraux, Samuel Thomas

    2012-09-03

    The quantum efficiency of solar cells, like of any photon detector, is dictated by the ability to absorb photons to create conducting carriers, and the efficiency to drive such carriers to electrodes for collection. Having a medium that enables full photon absorption in a short length, together with a long carrier lifetime that allows photo-generated carriers to reach electrodes before recombining are ideal, but are not always realistic. For example, silicon photovoltaics, despite being a major player in the solar cell market, suffer from the low absorption coefficient, thus requiring a thick absorbing layer which impairs the efficiency with which photogenerated carriers are collected. Radial silicon nanowires have been proposed as a candidate for reducing the optical absorption length and required processing purity in Si based solar cells without compromising their quantum efficiency and yet reducing the overall cell cost. On the one hand, incident light propagates along the axial dimension of the wires, and thus has a greater chance of being absorbed when the wire length extends beyond 10m due to inter-array light scattering effects. On the other hand, the core/shell p-i-n structure leads electrical current flow along sub-micron radii, which enables rapid collection of most photogenerated carriers as the transport length is typically less than the diffusion lengths of minority carriers. In this work, we perform Finite Difference Time Domain (FDTD) simulation to investigate the absorption process in arrayed radial nanowires.

  2. Medium Bandgap Conjugated Polymer for High Performance Polymer Solar Cells Exceeding 9% Power Conversion Efficiency.

    PubMed

    Jung, Jae Woong; Liu, Feng; Russell, Thomas P; Jo, Won Ho

    2015-12-02

    Two medium-bandgap polymers composed of benzo[1,2-b:4,5-b']dithiohpene and 2,1,3-benzothiadiazole with 6-octyl-thieno[3,2-b]thiophene as a π-bridge unit are synthesized and their photovoltaic properties are analyzed. The two polymers have deep highest occupied molecular orbital energy levels, high crystallinity, optimal bulk-heterojunction morphology, and efficient charge transport, resulting in a power conversion efficiency of as high as 9.44% for a single-junction polymer solar-cell device. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Origin of the high performance of perovskite solar cells with large grains

    SciTech Connect

    Chen, Jian; Shi, Tongfei Li, Xinhua; Zhou, Bukang; Cao, Huaxiang; Wang, Yuqi

    2016-02-01

    Due to excellent carrier transport characteristics, CH{sub 3}NH{sub 3}PbI{sub 3} film made of large single crystal grains is considered as a key to improve upon already remarkable perovskite solar cell (PSC) efficiency. We have used a simple and efficient solvent vapor annealing method to obtain CH{sub 3}NH{sub 3}PbI{sub 3} films with grain size over 1 μm. PSCs with different grain size films have been fabricated and verified the potential of large grains for improving solar cells performance. Moreover, the larger grain films have shown stronger light absorption ability and more photon-generated carriers under the same illumination. A detailed temperature-dependent PL study has indicated that it originates from larger radius and lower binding energy of donor-acceptor-pair (DAP) in larger grains, which makes the DAP is easily to be separated and difficult to be recombine.

  4. Origin of the high performance of perovskite solar cells with large grains

    NASA Astrophysics Data System (ADS)

    Chen, Jian; Shi, Tongfei; Li, Xinhua; Zhou, Bukang; Cao, Huaxiang; Wang, Yuqi

    2016-02-01

    Due to excellent carrier transport characteristics, CH3NH3PbI3 film made of large single crystal grains is considered as a key to improve upon already remarkable perovskite solar cell (PSC) efficiency. We have used a simple and efficient solvent vapor annealing method to obtain CH3NH3PbI3 films with grain size over 1 μm. PSCs with different grain size films have been fabricated and verified the potential of large grains for improving solar cells performance. Moreover, the larger grain films have shown stronger light absorption ability and more photon-generated carriers under the same illumination. A detailed temperature-dependent PL study has indicated that it originates from larger radius and lower binding energy of donor-acceptor-pair (DAP) in larger grains, which makes the DAP is easily to be separated and difficult to be recombine.

  5. Tuning the Thickness of Ba-Containing "Functional" Layer toward High-Performance Ceria-Based Solid Oxide Fuel Cells.

    PubMed

    Gong, Zheng; Sun, Wenping; Shan, Duo; Wu, Yusen; Liu, Wei

    2016-05-04

    Developing highly efficient ceria-based solid oxide fuel cells with high power density is still a big concern for commercial applications. In this work, a novel structured Ce0.8Sm0.2O2-δ (SDC)-based fuel cell with a bilayered anode consisting of Ni-SDC and Ni-BaZr0.1Ce0.7Y0.2O3-δ (Ni-BZCY) was designed. In addition to the catalysis function, the Ni-BZCY anode "functional" layer also provides Ba source for generating an electron-blocking layer in situ at the anode/electrolyte interface during sintering. The Ni-BZCY thickness significantly influences the quality of the electron-blocking layer and electrochemical performances of the cell. The cell with a 50 μm thick Ni-BZCY layer exhibits the best performance in terms of open circuit voltage (OCV) and peak power density (1068 mW cm(-2) at 650 °C). The results demonstrate that this cell with an optimal structure has a distinct advantage of delivering high power performance with a high efficiency at reduced temperatures.

  6. High Performance Photovoltaic Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-05-169

    SciTech Connect

    Steiner, M.

    2012-07-01

    NREL will provide certified measurements of the conversion efficiency at high concentration for several multijunction solar cells that were fabricated by Cyrium Technologies. In an earlier phase of the CRADA, Cyrium provided epitaxially-grown material and NREL processed the samples into devices and measured the performance.

  7. High-Performance and Omnidirectional Thin-Film Amorphous Silicon Solar Cell Modules Achieved by 3D Geometry Design.

    PubMed

    Yu, Dongliang; Yin, Min; Lu, Linfeng; Zhang, Hanzhong; Chen, Xiaoyuan; Zhu, Xufei; Che, Jianfei; Li, Dongdong

    2015-11-01

    High-performance thin-film hydrogenated amorphous silicon solar cells are achieved by combining macroscale 3D tubular substrates and nanoscaled 3D cone-like antireflective films. The tubular geometry delivers a series of advantages for large-scale deployment of photovoltaics, such as omnidirectional performance, easier encapsulation, decreased wind resistance, and easy integration with a second device inside the glass tube. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Development of a High Volume Capable Process to Manufacture High Performance Photovoltaic Cells: Cooperative Research and Development Final Report, CRADA Number CRD-08-322

    SciTech Connect

    Geisz, J. F.

    2012-11-01

    The intent of the work is for RFMD and NREL to cooperate in the development of a commercially viable and high volume capable process to manufacture high performance photovoltaic cells, based on inverted metamorphic (IMM) GaAs technology. The successful execution of the agreement will result in the production of a PV cell using technology that is capable of conversion efficiency at par with the market at the time of release (reference 2009: 37-38%), using RFMD's production facilities. The CRADA work has been divided into three phases: (1) a foundation phase where the teams will demonstrate the manufacturing of a basic PV cell at RFMD's production facilities; (2) a technology demonstration phase where the teams will demonstrate the manufacturing of prototype PV cells using IMM technology at RFMD's production facilities, and; (3) a production readiness phase where the teams will demonstrate the capability to manufacture PV cells using IMM technology with high yields, high reliability, high reproducibility and low cost.

  9. Development of high-performance transparent conducting oxides and their impact on the performance of CdS/CdTe solar cells

    SciTech Connect

    Coutts, T.J.; Wu, X.; Sheldon, P.; Rose, D.H.

    1998-09-01

    This paper begins with a review of the modeled performance of transparent conducting oxides (TCOs) as a function of their free-carrier concentration, mobility, and film thickness. It is shown that it is vital to make a film with high mobility to minimize the width and height of the free-carrier absorption band, and to optimize the optical properties. The free-carrier concentration must be kept sufficiently small that the absorption band does not extend into that part of the spectrum to which the solar cell responds. Despite this consideration, a high electrical conductivity is essential to minimize series resistance losses. Hence, a high mobility is vital for these materials. The fabrication of thin-films of cadmium stannate is then discussed, and their performance is compared with that of tin oxide, both optically and as these materials influence the performance of CdTe solar cells.

  10. High performance of inverted polymer solar cells with cobalt oxide as hole-transporting layer

    NASA Astrophysics Data System (ADS)

    Wang, Xiangdong; Peng, Qing; Zhu, Weiguo; Lei, Gangtie

    2015-05-01

    Cobalt oxide (II, III) (CoOx) was inserted as efficient hole-transporting interlayer between the active layer and top electrode in inverted polymer solar cells (PSCs) with titanium (diisopropoxide) bis(2, 4-pentanedionate) (TIPD) as an electron selective layer. The work function of CoOx was measured by Kelvin probe and the device performances with different thicknesses of cobalt oxide were studied. The device with CoOx exhibited a remarkable improvement in power conversion efficiency compared with that without CoOx, which indicated that CoOx efficiently prevented the recombination of charge carriers at the organic/top electrode interface. The performance improvement was attributed to the fact that the CoOx thin film can module the Schottky barrier and form an ohmic contact at the organic/metal interface, which makes it a promising hole-transporting layer.

  11. An integrated approach to realizing high-performance liquid-junction quantum dot sensitized solar cells.

    PubMed

    McDaniel, Hunter; Fuke, Nobuhiro; Makarov, Nikolay S; Pietryga, Jeffrey M; Klimov, Victor I

    2013-01-01

    Solution-processed semiconductor quantum dot solar cells offer a path towards both reduced fabrication cost and higher efficiency enabled by novel processes such as hot-electron extraction and carrier multiplication. Here we use a new class of low-cost, low-toxicity CuInSexS2-x quantum dots to demonstrate sensitized solar cells with certified efficiencies exceeding 5%. Among other material and device design improvements studied, use of a methanol-based polysulfide electrolyte results in a particularly dramatic enhancement in photocurrent and reduced series resistance. Despite the high vapour pressure of methanol, the solar cells are stable for months under ambient conditions, which is much longer than any previously reported quantum dot sensitized solar cell. This study demonstrates the large potential of CuInSexS2-x quantum dots as active materials for the realization of low-cost, robust and efficient photovoltaics as well as a platform for investigating various advanced concepts derived from the unique physics of the nanoscale size regime.

  12. An integrated approach to realizing high-performance liquid-junction quantum dot sensitized solar cells

    PubMed Central

    McDaniel, Hunter; Fuke, Nobuhiro; Makarov, Nikolay S.; Pietryga, Jeffrey M.; Klimov, Victor I.

    2013-01-01

    Solution-processed semiconductor quantum dot solar cells offer a path towards both reduced fabrication cost and higher efficiency enabled by novel processes such as hot-electron extraction and carrier multiplication. Here we use a new class of low-cost, low-toxicity CuInSexS2−x quantum dots to demonstrate sensitized solar cells with certified efficiencies exceeding 5%. Among other material and device design improvements studied, use of a methanol-based polysulfide electrolyte results in a particularly dramatic enhancement in photocurrent and reduced series resistance. Despite the high vapour pressure of methanol, the solar cells are stable for months under ambient conditions, which is much longer than any previously reported quantum dot sensitized solar cell. This study demonstrates the large potential of CuInSexS2−x quantum dots as active materials for the realization of low-cost, robust and efficient photovoltaics as well as a platform for investigating various advanced concepts derived from the unique physics of the nanoscale size regime. PMID:24322379

  13. Utilization of Tabula Rasa to Stabilize Bulk Lifetimes in n-Cz Silicon for High-Performance Solar Cell Processing

    SciTech Connect

    LaSalvia, Vincenzo; Jensen, Mallory Ann; Youssef, Amanda; Nemeth, William; Page, Matthew; Buonassisi, Tonio; Stradins, Paul

    2016-11-21

    We investigate a high temperature, high cooling-rate anneal Tabula Rasa (TR) and report its implications on n-type Czochralski-grown silicon (n-Cz Si) for photovoltaic fabrication. Tabula Rasa aims at dissolving and homogenizing oxygen precipitate nuclei that can grow during the cell process steps and degrade the cell performance due to their high internal gettering and recombination activity. The Tabula Rasa thermal treatment is performed in a clean tube furnace with cooling rates >100 degrees C/s. We characterize the bulk lifetime by Sinton lifetime and photoluminescence mapping just after Tabula Rasa, and after the subsequent cell processing. After TR, the bulk lifetime surprisingly degrades to <; 0.1ms, only to recover to values equal or higher than the initial non-treated wafer (several ms), after typical high temperature cell process steps. Those include boron diffusion and oxidation; phosphorus diffusion/oxidation; ambient annealing at 850 degrees C; and crystallization annealing of tunneling-passivating contacts (doped polycrystalline silicon on 1.5 nm thermal oxide). The drastic lifetime improvement during high temperature cell processing is attributed to improved external gettering of metal impurities and annealing of intrinsic point defects. Time and injection dependent lifetime spectroscopy further reveals the mechanisms of lifetime improvement after Tabula Rasa treatment. Additionally, we report the efficacy of Tabula Rasa on n-type Cz-Si wafers and its dependence on oxygen concentration, correlated to position within the ingot.

  14. Performance comparison between high temperature and traditional proton exchange membrane fuel cell stacks using electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhu, Ying; Zhu, Wenhua H.; Tatarchuk, Bruce J.

    2014-06-01

    A temperature above 100 °C is always desired for proton exchange membrane (PEM) fuel cell operation. It not only improves kinetic and mass transport processes, but also facilitates thermal and water management in fuel cell systems. Increased carbon monoxide (CO) tolerance at higher operating temperature also simplifies the pretreatment of fuel supplement. The novel phosphoric acid (PA) doped polybenzimidazole (PBI) membranes achieve PEM fuel cell operations above 100 °C. The performance of a commercial high temperature (HT) PEM fuel cell stack module is studied by measuring its impedance under various current loads when the operating temperature is set at 160 °C. The contributions of kinetic and mass transport processes to stack impedance are analyzed qualitatively and quantitatively by equivalent circuit (EC) simulation. The performance of a traditional PEM fuel cell stack module operated is also studied by impedance measurement and EC simulation. The operating temperature is self-stabilized between 40 °C and 65 °C. An enhancement of the HT-PEM fuel cell stack in polarization impedance is evaluated by comparing to the traditional PEM fuel cell stack. The impedance study on two commercial fuel cell stacks reveals the real situation of current fuel cell development.

  15. Organic Small Molecule as the Underlayer Toward High Performance Planar Perovskite Solar Cells.

    PubMed

    Cong, Shan; Yang, Hao; Lou, Yanhui; Han, Liang; Yi, Qinghua; Wang, Haibo; Sun, Yinghui; Zou, Guifu

    2017-01-25

    The underlayer plays an important role for organic-inorganic hybrid perovskite formation and charge transport in perovskite solar cells (PSCs). Here, we employ a classical organic small molecule, 5,6,11,12-tetraphenyltetracene (rubrene), as the underlayer of perovskite films to achieve 15.83% of power conversion efficiency with remarkable moisture tolerance exposed to the atmosphere. Experiments demonstrate rubrene hydrophobic underlayer not only drives the crystalline grain growth of high quality perovskite, but also contributes to the moisture tolerance of PSCs. Moreover, the matching energy level of the desirable underlayer is conductive to extracting holes and blocking electrons at anode in PSCs. This introduction of organic small molecule into PSCs provides alternative materials for interface optimization, as well as platform for flexible and wearable solar cells.

  16. High-performance semitransparent perovskite solar cells with solution-processed silver nanowires as top electrodes.

    PubMed

    Guo, Fei; Azimi, Hamed; Hou, Yi; Przybilla, Thomas; Hu, Mengyao; Bronnbauer, Carina; Langner, Stefan; Spiecker, Erdmann; Forberich, Karen; Brabec, Christoph J

    2015-02-07

    In this work, we report efficient semitransparent perovskite solar cells using solution-processed silver nanowires (AgNWs) as top electrodes. A thin layer of zinc oxide nanoparticles is introduced beneath the AgNWs, which fulfills two essential functionalities: it ensures ohmic contact between the PC60BM and the AgNWs and it serves as a physical foundation that enables the solution-deposition of AgNWs without causing damage to the underlying perovskite. The as-fabricated semitransparent perovskite cells show a high fill factor of 66.8%, Voc = 0.964 V, Jsc = 13.18 mA cm(-2), yielding an overall efficiency of 8.49% which corresponds to 80% of the reference devices with reflective opaque electrodes.

  17. Graphene oxide as a sulfur immobilizer in high performance lithium/sulfur cells

    DOEpatents

    Zhang, Yuegang; Cairns, Elton J.; Ji, Liwen; Rao, Mumin

    2017-06-06

    The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (.about.tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.-1, and stable cycling for more than 50 deep cycles at 0.1 C.

  18. High-performance n-MoS2/i-SiO2/p-Si heterojunction solar cells.

    PubMed

    Hao, L Z; Gao, W; Liu, Y J; Han, Z D; Xue, Q Z; Guo, W Y; Zhu, J; Li, Y R

    2015-05-14

    A solar cell based on the n-MoS2/i-SiO2/p-Si heterojunction is fabricated. The device exhibits a high power-conversion efficiency of 4.5% due to the incorporation of a nano-scale SiO2 buffer into the MoS2/Si interface. The present device architectures are envisaged as potentially valuable candidates for high-performance photovoltaic devices.

  19. High-performance n-MoS2/i-SiO2/p-Si heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Hao, L. Z.; Gao, W.; Liu, Y. J.; Han, Z. D.; Xue, Q. Z.; Guo, W. Y.; Zhu, J.; Li, Y. R.

    2015-04-01

    A solar cell based on the n-MoS2/i-SiO2/p-Si heterojunction is fabricated. The device exhibits a high power-conversion efficiency of 4.5% due to the incorporation of a nano-scale SiO2 buffer into the MoS2/Si interface. The present device architectures are envisaged as potentially valuable candidates for high-performance photovoltaic devices.

  20. High performance polymer development

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1991-01-01

    The term high performance as applied to polymers is generally associated with polymers that operate at high temperatures. High performance is used to describe polymers that perform at temperatures of 177 C or higher. In addition to temperature, other factors obviously influence the performance of polymers such as thermal cycling, stress level, and environmental effects. Some recent developments at NASA Langley in polyimides, poly(arylene ethers), and acetylenic terminated materials are discussed. The high performance/high temperature polymers discussed are representative of the type of work underway at NASA Langley Research Center. Further improvement in these materials as well as the development of new polymers will provide technology to help meet NASA future needs in high performance/high temperature applications. In addition, because of the combination of properties offered by many of these polymers, they should find use in many other applications.

  1. Long Term Performance Retention Test Using High Power COTS NiCd and NiMH Cells

    NASA Technical Reports Server (NTRS)

    Hall, Dan; Darcy, Eric; Strangways, Brad; Nelson, Tim

    2003-01-01

    This slide presentation reviews the tests and results for performance retention of high powered commercial off the shelf (COTS) NiCd, and NiMH cells. Electromechanical actuators for space flight requires short duration high power batteries. The concern is that NiCd battery designs demonstrate an unfavorable power degradation after long periods of inactivity. Cycling can recover some of the decay, but this reduces the readiness that these batteries must have. Two 5-cell SubC stick test batteries ere chosen using NiCd and NiMH were tested and then the differences for charge maintenance were compared.

  2. CoS-Graphene Composite Counter Electrode for High Performance Dye-Sensitized Solar Cell.

    PubMed

    Wang, Fen; Wu, Congcong; Tan, Yuan; Jin, Tetsuro; Chi, Bo; Pu, Jian; Jian, Li

    2015-02-01

    CoS-graphene composite counter electrode for dye-sensitized solar cell (DSSC) was prepared by coating hydrothermal synthesized CoS with graphene onto the FTO conductive glass. SEM shows that CoS particles are uniformly dispersed in the graphene. The result confirms that the prepared composite counter electrode is of highly electrocatalytic activity towards iodine reduction, which is even better than Pt electrode. And cyclic voltammetry measurement also shows that the composite counter electrode has good stability after 100 scan cycles. DSSC with CoS-graphene as composite counter electrode achieves a maximum power conversion efficiency of 6.31%, which is better than Pt electrode.

  3. High-performance membrane-electrode assembly with an optimal polytetrafluoroethylene content for high-temperature polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Jeong, Gisu; Kim, MinJoong; Han, Junyoung; Kim, Hyoung-Juhn; Shul, Yong-Gun; Cho, EunAe

    2016-08-01

    Although high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) have a high carbon monoxide tolerance and allow for efficient water management, their practical applications are limited due to their lower performance than conventional low-temperature PEMFCs. Herein, we present a high-performance membrane-electrode assembly (MEA) with an optimal polytetrafluoroethylene (PTFE) content for HT-PEMFCs. Low or excess PTFE content in the electrode leads to an inefficient electrolyte distribution or severe catalyst agglomeration, respectively, which hinder the formation of triple phase boundaries in the electrodes and result in low performance. MEAs with PTFE content of 20 wt% have an optimal pore structure for the efficient formation of electrolyte/catalyst interfaces and gas channels, which leads to high cell performance of approximately 0.5 A cm-2 at 0.6 V.

  4. Role of Metal Oxide Electron-Transport Layer Modification on the Stability of High Performing Perovskite Solar Cells.

    PubMed

    Singh, Trilok; Singh, Jai; Miyasaka, Tsutomu

    2016-09-22

    Organic-inorganic hybrid perovskite light absorbers have recently emerged as a "holy grail" for next generation thin-film photovoltaics with excellent optoelectronics properties and low fabrication cost. In a very short span of time, we have witnessed a pronounced and unexpected progress in organic- inorganic perovskite solar cells (PSCs) with a vertical rise in power conversion efficiency from 3.8 to 22.1 %. In this manuscript we focus specifically on the recent development of metal oxide-based electron-transporting layer (ETL) modification for high performing PSCs and their stability. This review highlights various methodologies to modify existing compact/scaffold layers for improving device performance and stability. Various aspects of the ETL are discussed with different metal oxide compact layers in their relation to modification in mesoporous layers towards the design of a cell structure with high performance and stability.

  5. Ambient Engineering for High-Performance Organic-Inorganic Perovskite Hybrid Solar Cells.

    PubMed

    Huang, Jiabin; Yu, Xuegong; Xie, Jiangsheng; Xu, Dikai; Tang, Zeguo; Cui, Can; Yang, Deren

    2016-08-24

    Considering the evaporation of solvents during fabrication of perovskite films, the organic ambience will present a significant influence on the morphologies and properties of perovskite films. To clarify this issue, various ambiences of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and chlorobenzene (CBZ) are introduced during fabrication of perovskite films by two-step sequential deposition method. The results reveal that an ambient CBZ atmosphere is favorable to control the nucleation and growth of CH3NH3PbI3 grains while the others present a negative effect. The statistical results show that the average efficiencies of perovskite solar cells processed in an ambient CBZ atmosphere can be significantly improved by a relatively average value of 35%, compared with those processed under air. The efficiency of the best perovskite solar cells can be improved from 10.65% to 14.55% by introducing this ambience engineering technology. The CH3NH3PbI3 film with large-size grains produced in an ambient CBZ atmosphere can effectively reduce the density of grain boundaries, and then the recombination centers for photoinduced carriers. Therefore, a higher short-circuit current density is achieved, which makes main contribution to the improvement in efficiency. These results provide vital progress toward understanding the role of ambience in the realization of highly efficient perovskite solar cells.

  6. Three-dimensional graphene-carbon nanotube hybrid for high-performance enzymatic biofuel cells.

    PubMed

    Prasad, Kenath Priyanka; Chen, Yun; Chen, Peng

    2014-03-12

    Enzymatic biofuel cells (EBFCs) are promising renewable and implantable power sources. However, their power output is often limited by inefficient electron transfer between the enzyme molecules and the electrodes, hindered mass transport, low conductivity, and small active surface area of the electrodes. To tackle these issues, we herein demonstrated a novel EBFC equipped with enzyme-functionalized 3D graphene-single walled carbon nanotubes (SWCNTs) hybrid electrodes using the naturally abundant glucose as the fuel and oxygen as the oxidizer. Such EBFCs, with high stability, can nearly attain the theoretical limit of open circuit voltage (∼1.2 V) and a high power density ever reported (2.27 ± 0.11 mW cm(-2)).

  7. Extraocular muscle satellite cells are high performance myo-engines retaining efficient regenerative capacity in dystrophin deficiency.

    PubMed

    Stuelsatz, Pascal; Shearer, Andrew; Li, Yunfei; Muir, Lindsey A; Ieronimakis, Nicholas; Shen, Qingwu W; Kirillova, Irina; Yablonka-Reuveni, Zipora

    2015-01-01

    Extraocular muscles (EOMs) are highly specialized skeletal muscles that originate from the head mesoderm and control eye movements. EOMs are uniquely spared in Duchenne muscular dystrophy and animal models of dystrophin deficiency. Specific traits of myogenic progenitors may be determinants of this preferential sparing, but very little is known about the myogenic cells in this muscle group. While satellite cells (SCs) have long been recognized as the main source of myogenic cells in adult muscle, most of the knowledge about these cells comes from the prototypic limb muscles. In this study, we show that EOMs, regardless of their distinctive Pax3-negative lineage origin, harbor SCs that share a common signature (Pax7(+), Ki67(-), Nestin-GFP(+), Myf5(nLacZ+), MyoD-positive lineage origin) with their limb and diaphragm somite-derived counterparts, but are remarkably endowed with a high proliferative potential as revealed in cell culture assays. Specifically, we demonstrate that in adult as well as in aging mice, EOM SCs possess a superior expansion capacity, contributing significantly more proliferating, differentiating and renewal progeny than their limb and diaphragm counterparts. These robust growth and renewal properties are maintained by EOM SCs isolated from dystrophin-null (mdx) mice, while SCs from muscles affected by dystrophin deficiency (i.e., limb and diaphragm) expand poorly in vitro. EOM SCs also retain higher performance in cell transplantation assays in which donor cells were engrafted into host mdx limb muscle. Collectively, our study provides a comprehensive picture of EOM myogenic progenitors, showing that while these cells share common hallmarks with the prototypic SCs in somite-derived muscles, they distinctively feature robust growth and renewal capacities that warrant the title of high performance myo-engines and promote consideration of their properties for developing new approaches in cell-based therapy to combat skeletal muscle wasting.

  8. High-performance anode-supported solid oxide fuel cell with impregnated electrodes

    NASA Astrophysics Data System (ADS)

    Osinkin, D. A.; Bogdanovich, N. M.; Beresnev, S. M.; Zhuravlev, V. D.

    2015-08-01

    The 61%NiO + 39%Zr0.84Y0.16O1.92 (NiO-YSZ) and 56%NiO + 44%Zr0.83Sc0.16Ce0.01O1.92 (NiO-CeSSZ) composite powders have been prepared using two-steps and one-step combustion synthesis, respectively. The Ni-YSZ anode substrate with a low level of electrical resistance (less than 1 mOhm cm) and porosity of about 53% in the reduced state was fabricated. The functional layer of the anode with the high level of electrochemical activity was made of NiO-CeSSZ. The single anode-supported solid oxide fuel cell with the bi-layer Ni-cermet anode, Zr0.84Sc0.16O1.92 film electrolyte and the Pt + 3% Zr0.84Y0.16O1.92 cathode was fabricated. The power density and the U-I curves of the fuel cell at initial state and after impregnation of the cathode and anode by praseodymium and cerium oxides, respectively, have been measured at different temperatures. The maximum of power density of the initial fuel cell was 0.35 W cm-2 at conditions of wet hydrogen (air) supply to the anode (cathode) at 900 °C. After the electrodes were impregnated, the value of power density increased by seven times and was approximately 2.4 W cm-2 at 0.6 V. It was suggested that after the electrodes impregnation the polarization resistance of the fuel cell was determined by the gas diffusion in the supported anode.

  9. New stopping cell capabilities: RF carpet performance at high gas density and cryogenic operation

    NASA Astrophysics Data System (ADS)

    Ranjan, M.; Purushothaman, S.; Dickel, T.; Geissel, H.; Plass, W. R.; Schäfer, D.; Scheidenberger, C.; Van de Walle, J.; Weick, H.; Dendooven, P.

    2011-12-01

    We have developed a stopping cell to be used at the FRS and Super-FRS (Super-conducting FRagment Separator) at the GSI Helmholtz Centre for Heavy-Ion Research and the Facility for Antiproton and Ion Research (FAIR), both in Darmstadt, Germany. The cell has a stopping volume with a length of 1 m and a diameter of 25 cm. It is aimed at operation with high-density helium gas (up to 0.2 mg/cm3). Ours is the first realisation of a stopping cell in which the required purity of the helium stopping gas is ensured by operation at cryogenic temperatures. On the exit side, the ions are guided to the exit hole by an RF carpet with 4 electrodes per mm, operating at a frequency of 5.8 MHz. We present the first commissioning results of the cryogenic stopping cell. Using 219Rn ions emitted as alpha-decay recoils from a 223Ra source, a combined ion survival and extraction efficiency between 10 and 25% is measured for helium gas at a temperature of 85 K and with a density up to 0.07 mg/cm3 (equivalent to a pressure of 430 mbar at room temperature). This density is almost two times higher than demonstrated up to now for RF ion repelling structures in helium gas. Given the operational and design parameters of the system, it is projected that this technology is useful up to a helium gas density of at least 0.2 mg/cm3.

  10. Loss mechanisms in high-efficiency solar cells: Study of material properties and high-efficiency solar-cell performance on material composition: Project tasks

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1985-01-01

    Loss mechanisms in high-efficiency solar cells were discussed. Fundamental limitations and practical solutions were stressed. Present cell efficiency is limited by many recombination sites: emitter, base, contacts, and oxide/silicon interface. Use of polysilicon passivation was suggested. After reduction of these losses, a 25% efficient cell could be built. A floating emitter cell design was shown that had the potential of low recombination losses.

  11. A complete carbon counter electrode for high performance quasi solid state dye sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Arbab, Alvira Ayoub; Peerzada, Mazhar Hussain; Sahito, Iftikhar Ali; Jeong, Sung Hoon

    2017-03-01

    The proposed research describes the design and fabrication of a quasi-solid state dye sensitized solar cells (Q-DSSCs) with a complete carbon based counter electrode (CC-CE) and gel infused membrane electrolyte. For CE, the platinized fluorinated tin oxide glass (Pt/FTO) was replaced by the soft cationic functioned multiwall carbon nanotubes (SCF-MWCNT) catalytic layer coated on woven carbon fiber fabric (CFF) prepared on handloom by interlacing of carbon filament tapes. SCF-MWCNT were synthesized by functionalization of cationised lipase from Candida Ragusa. Cationised enzyme solution was prepared at pH ∼3 by using acetic acid. The cationic enzyme functionalization of MWCNT causes the minimum damage to the tubular morphology and assist in fast anchoring of negative iodide ions present in membrane electrolyte. The high electrocatalytic activity and low charge transfer resistance (RCT = 2.12 Ω) of our proposed system of CC-CE shows that the woven CFF coated with cationised lipase treated carbon nanotubes enriched with positive surface ions. The Q-DSSCs fabricated with CC-CE and 5 wt% PEO gel infused PVDF-HFP membrane electrolyte exhibit power conversion efficiency of 8.90% under masking. Our suggested low cost and highly efficient system of CC-CE helps the proposed quasi-solid state DSSCs structure to stand out as sustainable next generation solar cells.

  12. Versatile Device Architectures for High-Performing Light-Soaking-Free Inverted Polymer Solar Cells.

    PubMed

    Yan, Yu; Cai, Feilong; Yang, Liyan; Li, Wei; Gong, Yanyan; Cai, Jinlong; Liu, Shuang; Gurney, Robert S; Liu, Dan; Wang, Tao

    2017-09-27

    Metal oxide charge transport layers have been widely employed to prepare inverted polymer solar cells with high efficiency and long lifetime. However, the intrinsic defects in the metal oxide layers, especially those prepared from low-temperature routes, overshadow the high efficiency that can be achieved and also introduce "light-soaking" issues to these devices. In this work, we have employed polyethyleneimine (PEI) and poly(9,9-bis(6'-(N,N-diethylamino)propyl)-fluorene-alt-9,9-bis-(3-ethyl(oxetane-3-ethyloxy)-hexyl)-fluorene] (PFN-OX) to modify our low-temperature-processed TiO2 electron transport layer (ETL) and demonstrated that the light-soaking issue can be effectively eliminated by PEI modifications because of the formation of abundant dipole moments, whereas PFN-OX was ineffective as a result of deficient dipole moments at the interface. Excitingly, PEI modifications enable versatile device architectures to obtain light-soaking-free, inverted PTB7-Th:PC71BM solar cells with efficiencies of over 10%, by adding PEI either in the bulk or as an adjacent layer below or above the TiO2 ETL.

  13. High-performance integrated perovskite and organic solar cells with efficient near-infrared harvesting

    NASA Astrophysics Data System (ADS)

    Kim, Junghwan; Lee, Kwanghee

    2016-09-01

    The integration of planar-type perovskite (Eg 1.5 eV) solar cells (PSCs) with a bulk-heterojunction (BHJ) composite comprising a near-infrared (NIR) absorbing conjugated polymer (Eg < 1.4 eV) and a fullerene derivative is a promising approach to overcoming the narrow absorption limit of typical PSCs. Nevertheless, integrated solar cells (ISCs) suffer from low fill factors (FFs) and inefficient NIR harvesting, mainly due to poor charge transport in the BHJ films. Here, we successfully demonstrate highly efficient P-I-N perovskite/BHJ ISCs with an enhanced FF and improved NIR harvesting by introducing a novel n-type semiconducting polymer and a new processing additive into the BHJ films. The optimized ISCs exhibit a power conversion efficiency (PCE) of 16.36%, which far surpasses that of the reference PSCs ( 14.70%) due to the increased current density (Jsc 20.04 mA cm-2) resulting from the additional NIR harvesting. Meanwhile, the optimized ISCs maintain a high FF of 77% and an open-circuit voltage (Voc) of 1.06 V. These results indicate that this approach is a versatile means of overcoming the absorption and theoretical efficiency limits of state-ofthe- art PSCs.

  14. Performance of high resistivity n+pp+ silicon solar cells under 1 MeV electron irradiation

    NASA Astrophysics Data System (ADS)

    Weinberg, I.; Goradia, C.; Swartz, C. K.; Hermann, A. M.

    1981-03-01

    High resistivity (1250 and 84 ohm-cm) n(+)pp(+) silicon solar cells were irradiated and their performance evaluated as a function of fluence. The greatest degradation in power occurred for the higher resistivity cell. The data were analyzed under open circuit conditions, and the components of V sub oc determined as a function of fluence. It was found that the voltage contributions from the front and back junctions decreased while the base component (V sub B) increased with fluence. The anomalous behavior of V sub B was attributed to an increase in the base minority carrier gradient with fluence. An argument that the increased power degradation in the 1250 ohm-cm cells was attributable to an increased voltage drop in the base is presented. Diffusion lengths calculated under high injection conditions were significantly greater than those determined under low injection. This was attributed to a saturation of recombination centers under high injection conditions.

  15. Performance of high resistivity n+pp+ silicon solar cells under 1 MeV electron irradiation

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Goradia, C.; Swartz, C. K.; Hermann, A. M.

    1981-01-01

    High resistivity (1250 and 84 ohm-cm) n(+)pp(+) silicon solar cells were irradiated and their performance evaluated as a function of fluence. The greatest degradation in power occurred for the higher resistivity cell. The data were analyzed under open circuit conditions, and the components of V sub oc determined as a function of fluence. It was found that the voltage contributions from the front and back junctions decreased while the base component (V sub B) increased with fluence. The anomalous behavior of V sub B was attributed to an increase in the base minority carrier gradient with fluence. An argument that the increased power degradation in the 1250 ohm-cm cells was attributable to an increased voltage drop in the base is presented. Diffusion lengths calculated under high injection conditions were significantly greater than those determined under low injection. This was attributed to a saturation of recombination centers under high injection conditions.

  16. Rational material, interface, and device engineering for high-performance polymer and perovskite solar cells (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Jen, Alex K.

    2015-10-01

    The performance of polymer and hybrid solar cells is also strongly dependent on their efficiency in harvesting light, exciton dissociation, charge transport, and charge collection at the metal/organic/metal oxide or the metal/perovskite/metal oxide interfaces. Our laboratory employs a molecular engineering approach to develop processible low band-gap polymers with high charge carrier mobility that can enhance power conversion efficiency of the single junction solar cells to values as high as ~11%. We have also developed several innovative strategies to modify the interface of bulk-heterojunction devices and create new device architectures to fully explore their potential for solar applications. In this talk, the integrated approach of combining material design, interface, and device engineering to significantly improve the performance of polymer and hybrid perovskite photovoltaic cells will be discussed. Specific emphasis will be placed on the development of low band-gap polymers with reduced reorganizational energy and proper energy levels, formation of optimized morphology of active layer, and minimized interfacial energy barriers using functional conductive surfactants. At the end, several new device architectures and optical engineering strategies to make tandem cells and semitransparent solar cells will be discussed to explore the full promise of polymer and perovskite hybrid solar cells.

  17. Ternary Blend Composed of Two Organic Donors and One Acceptor for Active Layer of High-Performance Organic Solar Cells.

    PubMed

    Lee, Jong Won; Choi, Yoon Suk; Ahn, Hyungju; Jo, Won Ho

    2016-05-04

    Ternary blends composed of two donor absorbers with complementary absorptions provide an opportunity to enhance the short-circuit current and thus the power conversion efficiency (PCE) of organic solar cells. In addition to complementary absorption of two donors, ternary blends may exhibit favorable morphology for high-performance solar cells when one chooses properly the donor pair. For this purpose, we develop a ternary blend with two donors (diketopyrrolopyrrole-based polymer (PTDPP2T) and small molecule ((TDPP)2Ph)) and one acceptor (PC71BM). The solar cell made of a ternary blend with 10 wt % (TDPP)2Ph exhibits higher PCE of 7.49% as compared with the solar cells with binary blends, PTDPP2T:PC71BM (6.58%) and (TDPP)2Ph:PC71BM (3.21%). The higher PCE of the ternary blend solar cell is attributed mainly to complementary absorption of two donors. However, a further increase in (TDPP)2Ph content in the ternary blend (>10 wt %) decreases the PCE. The ternary blend with 10 wt % (TDPP)2Ph exhibits well-developed morphology with narrow-sized fibrils while the blend with 15 wt % (TDPP)2Ph shows phase separation with large-sized domains, demonstrating that the phase morphology and compatibility of ternary blend are important factors to achieve a high-performance solar cell made of ternary blends.

  18. Novel p-Type Conductive Semiconductor Nanocrystalline Film as the Back Electrode for High-Performance Thin Film Solar Cells.

    PubMed

    Zhang, Ming-Jian; Lin, Qinxian; Yang, Xiaoyang; Mei, Zongwei; Liang, Jun; Lin, Yuan; Pan, Feng

    2016-02-10

    Thin film solar cells, due to the low cost, high efficiency, long-term stability, and consumer applications, have been widely applied for harvesting green energy. All of these thin film solar cells generally adopt various metal thin films as the back electrode, like Mo, Au, Ni, Ag, Al, graphite, and so forth. When they contact with p-type layer, it always produces a Schottky contact with a high contact potential barrier, which greatly affects the cell performance. In this work, we report for the first time to find an appropriate p-type conductive semiconductor film, digenite Cu9S5 nanocrystalline film, as the back electrode for CdTe solar cells as the model device. Its low sheet resistance (16.6 Ω/sq) could compare to that of the commercial TCO films (6-30 Ω/sq), like FTO, ITO, and AZO. Different from the traditonal metal back electrode, it produces a successive gradient-doping region by the controllable Cu diffusion, which greatly reduces the contact potential barrier. Remarkably, it achieved a comparable power conversion efficiency (PCE, 11.3%) with the traditional metal back electrode (Cu/Au thin films, 11.4%) in CdTe cells and a higher PCE (13.8%) with the help of the Au assistant film. We believe it could also act as the back electrode for other thin film solar cells (α-Si, CuInS2, CIGSe, CZTS, etc.), for their performance improvement.

  19. Controllable self-induced passivation of hybrid lead iodide perovskites toward high performance solar cells.

    PubMed

    Chen, Qi; Zhou, Huanping; Song, Tze-Bin; Luo, Song; Hong, Ziruo; Duan, Hsin-Sheng; Dou, Letian; Liu, Yongsheng; Yang, Yang

    2014-07-09

    To improve the performance of the polycrystalline thin film devices, it requires a delicate control of its grain structures. As one of the most promising candidates among current thin film photovoltaic techniques, the organic/inorganic hybrid perovskites generally inherit polycrystalline nature and exhibit compositional/structural dependence in regard to their optoelectronic properties. Here, we demonstrate a controllable passivation technique for perovskite films, which enables their compositional change, and allows substantial enhancement in corresponding device performance. By releasing the organic species during annealing, PbI2 phase is presented in perovskite grain boundaries and at the relevant interfaces. The consequent passivation effects and underlying mechanisms are investigated with complementary characterizations, including scanning electron microscopy (SEM), X-ray diffraction (XRD), time-resolved photoluminescence decay (TRPL), scanning Kelvin probe microscopy (SKPM), and ultraviolet photoemission spectroscopy (UPS). This controllable self-induced passivation technique represents an important step to understand the polycrystalline nature of hybrid perovskite thin films and contributes to the development of perovskite solar cells judiciously.

  20. High-Performance Alkaline Direct Methanol Fuel Cell using a Nitrogen-Postdoped Anode

    DTIC Science & Technology

    2014-01-01

    methanol strip - ping voltammetry {MSV) technique.rm Notably, CO stripping curves could not be obtained for either the N-doped PtRu/C or the undoped...rate of 5 mV s-1 at 25 oc. The ECSA of the cathode was measured by cyclic voltammetry (CV). The cathode of the MEA was fed with 2M NaOH for 30 min at...terfacial structure, and hence performance, the study em- ployed very high catalyst loadings for both the anode (PtRu black 8 mgcm-2) and cathode {Pt

  1. High-Performance Perovskite Solar Cells Engineered by an Ammonia Modified Graphene Oxide Interfacial Layer.

    PubMed

    Feng, Shanglei; Yang, Yingguo; Li, Meng; Wang, Jinmiao; Cheng, Zhendong; Li, Jihao; Ji, Gengwu; Yin, Guangzhi; Song, Fei; Wang, Zhaokui; Li, Jingye; Gao, Xingyu

    2016-06-15

    The introduction of an ammonia modified graphene oxide (GO:NH3) layer into perovskite-based solar cells (PSCs) with a structure of indium-tin oxide (ITO)/poly(3,4-ethylene-dioxythiophene):poly(4-styrenesulfonate) ( PSS)-GO: NH3/CH3NH3PbI3-xClx/phenyl C61-butyric acid methyl ester (PCBM)/(solution Bphen) sBphen/Ag improves their performance and perovskite structure stability significantly. The fabricated devices with a champion PCE up to 16.11% are superior in all the performances in comparison with all the reference devices without the GO:NH3 layer. To understand the improved device performances, synchrotron-based grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), and UV-visible absorption measurements have been conducted on perovskite films on different substrates. It was found that these improvements should be partially attributed to the improved crystallization and preferred orientation order of peovskite structure, partially to the improved morphology with nearly complete coverage, partially to the enhanced optical absorption caused by the PSS-GO:NH3 layer, and partially to the better matched energy-level-alignment at the perovskite interface. Furthermore, the device was shown to be more stable in the ambient condition, which is clearly associated with the improved peovskite structure stability by the GO:NH3 layer observed by the GIXRD measurements. All these achievements will promote more applications of chemically modified graphene oxide interfacial layer in the PSCs as well as other organic multilayer devices.

  2. Very High Performance Polymer Solar Cells -- A step closer to reality

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2010-03-01

    Recently, together with our research partners, we have demonstrated polymer solar cell with a power conversion efficiency (PCE) of close to 8%. This is achieved by several technical and scientific approaches. A new series of photovoltaic polymers based on a low bandgap polymer, poly[4,8-bis-substituted-benzo [1,2-b:4,5-b' ]dithiophene-2,6-diyl-alt-4-substituted-thieno[3,4-b]thio- phene-2,6-diyl] (PBDTTT), were designed and synthesized by chemists from University of Chicago and Solarmer Energy Inc., a start-up from UCLA. By adding different electron-withdrawing functional groups, the open circuit voltage (Voc) of polymers based on PBDTTT can be systematically increased, step by step. It was found that in this polymer system, the bandgap of the polymer can be maintained when the functional groups are added. As a result, the molecular energy levels of PBDTTT can be tuned without sacrificing the light harvesting. Together with the increased Voc, a polymer solar cell with efficiency as high as 7.7% PCE was realized, bringing them one step closer to reality for practical application.

  3. Plasma nitriding induced growth of Pt-nanowire arrays as high performance electrocatalysts for fuel cells.

    PubMed

    Du, Shangfeng; Lin, Kaijie; Malladi, Sairam K; Lu, Yaxiang; Sun, Shuhui; Xu, Qiang; Steinberger-Wilckens, Robert; Dong, Hanshan

    2014-09-22

    In this work, we demonstrate an innovative approach, combing a novel active screen plasma (ASP) technique with green chemical synthesis, for a direct fabrication of uniform Pt nanowire arrays on large-area supports. The ASP treatment enables in-situ N-doping and surface modification to the support surface, significantly promoting the uniform growth of tiny Pt nuclei which directs the growth of ultrathin single-crystal Pt nanowire (2.5-3 nm in diameter) arrays, forming a three-dimensional (3D) nano-architecture. Pt nanowire arrays in-situ grown on the large-area gas diffusion layer (GDL) (5 cm(2)) can be directly used as the catalyst electrode in fuel cells. The unique design brings in an extremely thin electrocatalyst layer, facilitating the charge transfer and mass transfer properties, leading to over two times higher power density than the conventional Pt nanoparticle catalyst electrode in real fuel cell environment. Due to the similar challenges faced with other nanostructures and the high availability of ASP for other material surfaces, this work will provide valuable insights and guidance towards the development of other new nano-architectures for various practical applications.

  4. Plasma nitriding induced growth of Pt-nanowire arrays as high performance electrocatalysts for fuel cells

    PubMed Central

    Du, Shangfeng; Lin, Kaijie; Malladi, Sairam K.; Lu, Yaxiang; Sun, Shuhui; Xu, Qiang; Steinberger-Wilckens, Robert; Dong, Hanshan

    2014-01-01

    In this work, we demonstrate an innovative approach, combing a novel active screen plasma (ASP) technique with green chemical synthesis, for a direct fabrication of uniform Pt nanowire arrays on large-area supports. The ASP treatment enables in-situ N-doping and surface modification to the support surface, significantly promoting the uniform growth of tiny Pt nuclei which directs the growth of ultrathin single-crystal Pt nanowire (2.5–3 nm in diameter) arrays, forming a three-dimensional (3D) nano-architecture. Pt nanowire arrays in-situ grown on the large-area gas diffusion layer (GDL) (5 cm2) can be directly used as the catalyst electrode in fuel cells. The unique design brings in an extremely thin electrocatalyst layer, facilitating the charge transfer and mass transfer properties, leading to over two times higher power density than the conventional Pt nanoparticle catalyst electrode in real fuel cell environment. Due to the similar challenges faced with other nanostructures and the high availability of ASP for other material surfaces, this work will provide valuable insights and guidance towards the development of other new nano-architectures for various practical applications. PMID:25241800

  5. Plasma nitriding induced growth of Pt-nanowire arrays as high performance electrocatalysts for fuel cells

    NASA Astrophysics Data System (ADS)

    Du, Shangfeng; Lin, Kaijie; Malladi, Sairam K.; Lu, Yaxiang; Sun, Shuhui; Xu, Qiang; Steinberger-Wilckens, Robert; Dong, Hanshan

    2014-09-01

    In this work, we demonstrate an innovative approach, combing a novel active screen plasma (ASP) technique with green chemical synthesis, for a direct fabrication of uniform Pt nanowire arrays on large-area supports. The ASP treatment enables in-situ N-doping and surface modification to the support surface, significantly promoting the uniform growth of tiny Pt nuclei which directs the growth of ultrathin single-crystal Pt nanowire (2.5-3 nm in diameter) arrays, forming a three-dimensional (3D) nano-architecture. Pt nanowire arrays in-situ grown on the large-area gas diffusion layer (GDL) (5 cm2) can be directly used as the catalyst electrode in fuel cells. The unique design brings in an extremely thin electrocatalyst layer, facilitating the charge transfer and mass transfer properties, leading to over two times higher power density than the conventional Pt nanoparticle catalyst electrode in real fuel cell environment. Due to the similar challenges faced with other nanostructures and the high availability of ASP for other material surfaces, this work will provide valuable insights and guidance towards the development of other new nano-architectures for various practical applications.

  6. Electrochemical performance of a graphene nanosheets anode in a high voltage lithium-ion cell.

    PubMed

    Vargas, Oscar; Caballero, Álvaro; Morales, Julián; Elia, Giuseppe Antonio; Scrosati, Bruno; Hassoun, Jusef

    2013-12-21

    We demonstrate the feasibility of a lithium ion battery (LIB) using graphene nanosheets (GNS) as the anode in combination with a LiNi(0.5)Mn(1.5)O4 (LNMO) high voltage, spinel-structure cathode. The GNS anode is characterized by a reversible capacity of the order of 600 mA h g(-1) and a working voltage of around 0.9 V, while the 4.8-V cathode has a theoretical capacity of 146.7 mA h g(-1). The full GNS/LiNi(0.5)Mn(1.5)O4 cell has an average working voltage of about 3.75 V and a capacity of the order of 100 mA h g(-1). The findings of this paper suggest that the graphene may be proposed as a suitable anode for application in lithium ion batteries.

  7. High-performance resistive switching characteristics of programmable metallization cell with oxidized Cu-Ti electrodes

    NASA Astrophysics Data System (ADS)

    Huang, Yu-Chih; Chou, Chia-Hsin; Liao, Chan-Yu; Tsai, Wan-Lin; Cheng, Huang-Chung

    2013-09-01

    Programmable metallization cell (PMC) memory devices with oxidized Cu-Ti alloy films as the bottom electrodes have been shown to exhibit a superior on/off state current ratio (memory window) of as high as 103 and endurance of 3000 cycles as compared to conventional pure copper and unoxidized Cu-Ti alloy electrodes. It was conjectured that the Cu-Ti alloy electrodes could obtain the appropriate amount of copper atoms to format and rupture the conductive filaments in the resistive switching layer. Furthermore, the oxidized Cu-Ti alloys could control the Cu cations from the Cu and Cu2O to the appropriate amountto achieve the most favorable PMC characteristics.

  8. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    SciTech Connect

    Jie Guan; Nguyen Minh

    2003-10-01

    This document summarizes the technical progress from April to September 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. Characteristics of doped lanthanum gallate (LSGMF) powder suitable for thin electrolyte fabrication have been defined. Bilayers with thin LSGMF electrolyte supported on an anode were fabricated and the fabrication process was improved. Preliminary performance was characterized. High performance cathode material Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} has been down-selected and is being optimized by modifying materials characteristics and processing parameters. The selected cathode exhibited excellent performance with cathode polarization of {approx}0.23 ohm-cm{sup 2} at 600 C.

  9. High performance a-Si solar cells and new fabrication methods for a-Si solar cells

    NASA Astrophysics Data System (ADS)

    Nakano, S.; Kuwano, Y.; Ohnishi, M.

    1986-12-01

    The super chamber, a separated UHV reaction-chamber system has been developed. A conversion efficiency of 11.7% was obtained for an a-Si solar cell using a high-quality i-layer deposited by the super chamber, and a p-layer fabricated by a photo-CVD method. As a new material, amorphous superlattice-structure films were fabricated by the photo-CVD method for the first time. Superlattice structure p-layer a-Si solar cells were fabricated, and a conversion efficiency of 10.5% was obtained. For the fabrication of integrated type a-Si solar cell modules, a laser pattering method was investigated. A thermal analysis of the multilayer structure was done. It was confirmed that selective scribing for a-Si, TCO and metal film is possible by controlling the laser power density. Recently developed a-Si solar power generation systems and a-Si solar cell roofing tiles are also described.

  10. Solution-Processible Crystalline NiO Nanoparticles for High-Performance Planar Perovskite Photovoltaic Cells

    NASA Astrophysics Data System (ADS)

    Kwon, Uisik; Kim, Bong-Gi; Nguyen, Duc Cuong; Park, Jong-Hyeon; Ha, Na Young; Kim, Seung-Joo; Ko, Seung Hwan; Lee, Soonil; Lee, Daeho; Park, Hui Joon

    2016-07-01

    In this work, we report on solution-based p-i-n-type planar-structured CH3NH3PbI3 perovskite photovoltaic (PV) cells, in which precrystallized NiO nanoparticles (NPs) without post-treatment are used to form a hole transport layer (HTL). X-ray diffraction and high-resolution transmission electron microscopy showed the crystallinity of the NPs, and atomic force microscopy and scanning electron microscopy confirmed the uniform surfaces of the resultant NiO thin film and the subsequent perovskite photoactive layer. Compared to the conventional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL, the NiO HTL had excellent energy-level alignment with that of CH3NH3PbI3 and improved electron-blocking capability, as analyzed by photoelectron spectroscopy and diode modeling, resulting in Voc ~0.13 V higher than conventional PEDOT:PSS-based devices. Consequently, a power conversion efficiency (PCE) of 15.4% with a high fill factor (FF, 0.74), short-circuit current density (Jsc, 20.2 mA·cm-2), and open circuit voltage (Voc, 1.04 V) having negligible hysteresis and superior air stability has been achieved.

  11. Solution-Processible Crystalline NiO Nanoparticles for High-Performance Planar Perovskite Photovoltaic Cells.

    PubMed

    Kwon, Uisik; Kim, Bong-Gi; Nguyen, Duc Cuong; Park, Jong-Hyeon; Ha, Na Young; Kim, Seung-Joo; Ko, Seung Hwan; Lee, Soonil; Lee, Daeho; Park, Hui Joon

    2016-07-28

    In this work, we report on solution-based p-i-n-type planar-structured CH3NH3PbI3 perovskite photovoltaic (PV) cells, in which precrystallized NiO nanoparticles (NPs) without post-treatment are used to form a hole transport layer (HTL). X-ray diffraction and high-resolution transmission electron microscopy showed the crystallinity of the NPs, and atomic force microscopy and scanning electron microscopy confirmed the uniform surfaces of the resultant NiO thin film and the subsequent perovskite photoactive layer. Compared to the conventional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) HTL, the NiO HTL had excellent energy-level alignment with that of CH3NH3PbI3 and improved electron-blocking capability, as analyzed by photoelectron spectroscopy and diode modeling, resulting in Voc ~0.13 V higher than conventional PSS-based devices. Consequently, a power conversion efficiency (PCE) of 15.4% with a high fill factor (FF, 0.74), short-circuit current density (Jsc, 20.2 mA·cm(-2)), and open circuit voltage (Voc, 1.04 V) having negligible hysteresis and superior air stability has been achieved.

  12. An Investigation on the Aggregation and Rheodynamics of Human Red Blood Cells Using High Performance Computations.

    PubMed

    Xu, Dong; Ji, Chunning; Avital, Eldad; Kaliviotis, Efstathios; Munjiza, Ante; Williams, John

    2017-01-01

    Studies on the haemodynamics of human circulation are clinically and scientifically important. In order to investigate the effect of deformation and aggregation of red blood cells (RBCs) in blood flow, a computational technique has been developed by coupling the interaction between the fluid and the deformable RBCs. Parallelization was carried out for the coupled code and a high speedup was achieved based on a spatial decomposition. In order to verify the code's capability of simulating RBC deformation and transport, simulations were carried out for a spherical capsule in a microchannel and multiple RBC transport in a Poiseuille flow. RBC transport in a confined tube was also carried out to simulate the peristaltic effects of microvessels. Relatively large-scale simulations were carried out of the motion of 49,512 RBCs in shear flows, which yielded a hematocrit of 45%. The large-scale feature of the simulation has enabled a macroscale verification and investigation of the overall characteristics of RBC aggregations to be carried out. The results are in excellent agreement with experimental studies and, more specifically, both the experimental and simulation results show uniform RBC distributions under high shear rates (60-100/s) whereas large aggregations were observed under a lower shear rate of 10/s.

  13. Solution-Processible Crystalline NiO Nanoparticles for High-Performance Planar Perovskite Photovoltaic Cells

    PubMed Central

    Kwon, Uisik; Kim, Bong-Gi; Nguyen, Duc Cuong; Park, Jong-Hyeon; Ha, Na Young; Kim, Seung-Joo; Ko, Seung Hwan; Lee, Soonil; Lee, Daeho; Park, Hui Joon

    2016-01-01

    In this work, we report on solution-based p-i-n-type planar-structured CH3NH3PbI3 perovskite photovoltaic (PV) cells, in which precrystallized NiO nanoparticles (NPs) without post-treatment are used to form a hole transport layer (HTL). X-ray diffraction and high-resolution transmission electron microscopy showed the crystallinity of the NPs, and atomic force microscopy and scanning electron microscopy confirmed the uniform surfaces of the resultant NiO thin film and the subsequent perovskite photoactive layer. Compared to the conventional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL, the NiO HTL had excellent energy-level alignment with that of CH3NH3PbI3 and improved electron-blocking capability, as analyzed by photoelectron spectroscopy and diode modeling, resulting in Voc ~0.13 V higher than conventional PEDOT:PSS-based devices. Consequently, a power conversion efficiency (PCE) of 15.4% with a high fill factor (FF, 0.74), short-circuit current density (Jsc, 20.2 mA·cm−2), and open circuit voltage (Voc, 1.04 V) having negligible hysteresis and superior air stability has been achieved. PMID:27465263

  14. High molecular weight insulating polymers can improve the performance of molecular solar cells

    NASA Astrophysics Data System (ADS)

    Huang, Ye; Wen, Wen; Kramer, Edward; Bazan, Guillermo

    2014-03-01

    Solution-processed molecular semiconductors for the fabrication of solar cells have emerged as a competitive alternative to their conjugated polymer counterparts, primarily because such materials systems exhibit no batch-to-batch variability, can be purified to a greater extent and offer precisely defined chemical structures. Highest power conversion efficiencies (PCEs) have been achieved through a combination of molecular design and the application of processing methods that optimize the bulk heterojunction (BHJ) morphology. However, one finds that the methods used for controlling structural order, for example the use of high boiling point solvent additives, have been inspired by examination of the conjugated polymer literature. It stands to reason that a different class of morphology modifiers should be sought that address challenges unique to molecular films, including difficulties in obtaining thicker films and avoiding the dewetting of active photovoltaic layers. Here we show that the addition of small quantities of high molecular weight polystyrene (PS) is a very simple to use and economically viable additive that improves PCE. Remarkably, the PS spontaneously accumulates away from the electrodes as separate domains that do not interfere with charge extraction and collection or with the arrangement of the donor and acceptor domains in the BHJ blend.

  15. GaInP/GaAs/GaInAs Monolithic Tandem Cells for High-Performance Solar Concentrators

    SciTech Connect

    Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

    2005-08-01

    We present a new approach for ultra-high-performance tandem solar cells that involves inverted epitaxial growth and ultra-thin device processing. The additional degree of freedom afforded by the inverted design allows the monolithic integration of high-, and medium-bandgap, lattice-matched (LM) subcell materials with lower-bandgap, lattice-mismatched (LMM) materials in a tandem structure through the use of transparent compositionally graded layers. The current work concerns an inverted, series-connected, triple-bandgap, GaInP (LM, 1.87 eV)/GaAs (LM, 1.42 eV)/GaInAs (LMM, {approx}1 eV) device structure grown on a GaAs substrate. Ultra-thin tandem devices are fabricated by mounting the epiwafers to pre-metallized Si wafer handles and selectively removing the parent GaAs substrate. The resulting handle-mounted, ultra-thin tandem cells have a number of important advantages, including improved performance and potential reclamation/reuse of the parent substrate for epitaxial growth. Additionally, realistic performance modeling calculations suggest that terrestrial concentrator efficiencies in the range of 40-45% are possible with this new tandem cell approach. A laboratory-scale (0.24 cm2), prototype GaInP/GaAs/GaInAs tandem cell with a terrestrial concentrator efficiency of 37.9% at a low concentration ratio (10.1 suns) is described, which surpasses the previous world efficiency record of 37.3%.

  16. High power, gel polymer lithium-ion cells with improved low temperature performance for NASA and DoD applications

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.; Chin, K. B.; Surampudi, S.; Narayanan, S. R.; Alamgir, Mohamed; Yu, Ji-Sang; Plichta, Edward P.

    2004-01-01

    Both NASA and the U.S. Army have interest in developing secondary energy storage devices that are capable of meeting the demanding performance requirements of aerospace and man-portable applications. In order to meet these demanding requirements, gel-polymer electrolyte-based lithium-ion cells are being actively considered, due to their promise of providing high specific energy and enhanced safety aspects.

  17. High power, gel polymer lithium-ion cells with improved low temperature performance for NASA and DoD applications

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.; Chin, K. B.; Surampudi, S.; Narayanan, S. R.; Alamgir, Mohamed; Yu, Ji-Sang; Plichta, Edward P.

    2004-01-01

    Both NASA and the U.S. Army have interest in developing secondary energy storage devices that are capable of meeting the demanding performance requirements of aerospace and man-portable applications. In order to meet these demanding requirements, gel-polymer electrolyte-based lithium-ion cells are being actively considered, due to their promise of providing high specific energy and enhanced safety aspects.

  18. Temperature-dependent Schottky barrier in high-performance organic solar cells

    PubMed Central

    Li, Hui; He, Dan; Zhou, Qing; Mao, Peng; Cao, Jiamin; Ding, Liming; Wang, Jizheng

    2017-01-01

    Organic solar cells (OSCs) have attracted great attention in the past 30 years, and the power conversion efficiency (PCE) now reaches around 10%, largely owning to the rapid material developments. Meanwhile with the progress in the device performance, more and more interests are turning to understanding the fundamental physics inside the OSCs. In the conventional bulk-heterojunction architecture, only recently it is realized that the blend/cathode Schottky junction serves as the fundamental diode for the photovoltaic function. However, few researches have focused on such junctions, and their physical properties are far from being well-understood. In this paper based on PThBDTP:PC71BM blend, we fabricated OSCs with PCE exceeding 10%, and investigated temperature-dependent behaviors of the junction diodes by various characterization including current-voltage, capacitance-voltage and impedance measurements between 70 to 290 K. We found the Schottky barrier height exhibits large inhomogeneity, which can be described by two sets of Gaussian distributions. PMID:28071700

  19. Temperature-dependent Schottky barrier in high-performance organic solar cells.

    PubMed

    Li, Hui; He, Dan; Zhou, Qing; Mao, Peng; Cao, Jiamin; Ding, Liming; Wang, Jizheng

    2017-01-10

    Organic solar cells (OSCs) have attracted great attention in the past 30 years, and the power conversion efficiency (PCE) now reaches around 10%, largely owning to the rapid material developments. Meanwhile with the progress in the device performance, more and more interests are turning to understanding the fundamental physics inside the OSCs. In the conventional bulk-heterojunction architecture, only recently it is realized that the blend/cathode Schottky junction serves as the fundamental diode for the photovoltaic function. However, few researches have focused on such junctions, and their physical properties are far from being well-understood. In this paper based on PThBDTP:PC71BM blend, we fabricated OSCs with PCE exceeding 10%, and investigated temperature-dependent behaviors of the junction diodes by various characterization including current-voltage, capacitance-voltage and impedance measurements between 70 to 290 K. We found the Schottky barrier height exhibits large inhomogeneity, which can be described by two sets of Gaussian distributions.

  20. Working from Both Sides: Composite Metallic Semitransparent Top Electrode for High Performance Perovskite Solar Cells.

    PubMed

    Dai, Xuezeng; Zhang, Ye; Shen, Heping; Luo, Qiang; Zhao, Xingyue; Li, Jianbao; Lin, Hong

    2016-02-01

    We report herein perovskite solar cells using solution-processed silver nanowires (AgNWs) as transparent top electrode with markedly enhanced device performance, as well as stability by evaporating an ultrathin transparent Au (UTA) layer beneath the spin-coated AgNWs forming a composite transparent metallic electrode. The interlayer serves as a physical separation sandwiched in between the perovskite/hole transporting material (HTM) active layer and the halide-reactive AgNWs top-electrode to prevent undesired electrode degradation and simultaneously functions to significantly promote ohmic contact. The as-fabricated semitransparent PSCs feature a Voc of 0.96 V, a Jsc of 20.47 mA cm(-2), with an overall PCE of over 11% when measured with front illumination and a Voc of 0.92 V, a Jsc of 14.29 mA cm(-2), and an overall PCE of 7.53% with back illumination, corresponding to approximately 70% of the value under normal illumination conditions. The devices also demonstrate exceptional fabrication repeatability and air stability.

  1. Sequential deposition: optimization of solvent swelling for high-performance polymer solar cells.

    PubMed

    Liu, Yao; Liu, Feng; Wang, Hsin-Wei; Nordlund, Dennis; Sun, Zhiwei; Ferdous, Sunzida; Russell, Thomas P

    2015-01-14

    Organic solar cells based on a typical DPP polymer were systematically optimized by a solvent swelling assisted sequential deposition process. We investigated the influence of solvent swelling on the morphology and structure order of the swollen film and the resultant device performance. Morphological and structural characterization confirmed the realization of ideal bulk heterojunctions using a suitable swelling solvent. A trilayered morphology was also found with the conjugated polymer concentrated bottom layer, PC71BM concentrated top layer, and interpenetrated networks of donor and acceptor in the middle by solvent swelling instead of thermal annealing in the sequential solution processing method. We proposed a simple strategy to optimize the sequential deposition fabricated devices by tuning the concentration of the PC71BM solution instead of thermal annealing. The best device showed a PCE of 7.59% with a Voc of 0.61 V, Jsc of 17.95 mA/cm(2), and FF of 69.6%, which is the highest reported efficiency for devices fabricated by a sequential processing method and among the best results for DPP polymers.

  2. Temperature-dependent Schottky barrier in high-performance organic solar cells

    NASA Astrophysics Data System (ADS)

    Li, Hui; He, Dan; Zhou, Qing; Mao, Peng; Cao, Jiamin; Ding, Liming; Wang, Jizheng

    2017-01-01

    Organic solar cells (OSCs) have attracted great attention in the past 30 years, and the power conversion efficiency (PCE) now reaches around 10%, largely owning to the rapid material developments. Meanwhile with the progress in the device performance, more and more interests are turning to understanding the fundamental physics inside the OSCs. In the conventional bulk-heterojunction architecture, only recently it is realized that the blend/cathode Schottky junction serves as the fundamental diode for the photovoltaic function. However, few researches have focused on such junctions, and their physical properties are far from being well-understood. In this paper based on PThBDTP:PC71BM blend, we fabricated OSCs with PCE exceeding 10%, and investigated temperature-dependent behaviors of the junction diodes by various characterization including current-voltage, capacitance-voltage and impedance measurements between 70 to 290 K. We found the Schottky barrier height exhibits large inhomogeneity, which can be described by two sets of Gaussian distributions.

  3. Performance of vapor-fed direct dimethyl ether fuel cell utilizing high temperature polybenzimidazole polymer electrolyte membrane

    NASA Astrophysics Data System (ADS)

    Neutzler, Jay; Qian, Guoqing; Huang, Kevin; Benicewicz, Brian

    2012-10-01

    There is increasing interest in dimethyl ether (DME) as a synthetic fuel. It has present-day relevance and introduces an effective path forward as an energy-dense, low-pressure hydrogen carrier/storage fuel for fuel cells with applications in transportation, stationary, and portable power. Direct reaction DME fuel cells have particular relevance to portable power. This study presents the performance of the vapor-fed direct reaction of DME using high temperature Polybenzimidazole (PBI) Polymer Electrolyte Membrane (PEM). Catalyzed PBI membrane utilized a Pt/Ru black anode and a Pt/C supported cathode. Performance was evaluated from temperatures of 180 °C-210 °C and at pressures from 100 kPa to 300 kPa. A strong performance correlation was observed in this study for these temperatures and pressures. A peak power density of 50 mW cm-2 was achieved at 180 °C without back pressure, whereas, an increase to 129 mW cm-2 was achieved at 210 °C at 300 kPa pressure. The performance of high temperature PBI PEMFCs with direct vapor-fed DME are investigated with emphasis on the critical variables of cell operation; temperature, back pressure, and humidity.

  4. Bismuth sulfide nanoflakes and nanorods as high performance photodetectors and photoelectrochemical cells

    NASA Astrophysics Data System (ADS)

    Chao, Junfeng; Xing, Shumin; Zhao, Yanchun; Gao, Suling; Song, Qinghua; Guo, Lixia; Wang, Di; Zhang, Tingliang

    2016-11-01

    Flake-like and rod-like bismuth sulfide nanostructures were synthesized via a facile polyol refluxing process. The rigid photodetectors based on both nanomaterials have the features of linear photocurrent characteristics and good sensitivity. Especially, the rigid bismuth sulfide nanoflakes photodetector has fast response time of 0.5 s and recovery time of 0.7 s. The flexible photodetectors were then fabricated on PET substrate, and this caused both the response time and the recovery time to increase by a factor of ∼2.5. Moreover, the photoelectrochemical (PEC) devices exhibited photosensitivity with the features of rapid response and recovery time, high on/off ratio and stable switching cycle performance. Our results imply that the two types of bismuth sulfide nanomaterials are prospective candidates for next generation photodetectors and optoelectronic switches.

  5. U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications.

    PubMed

    Houchins, Cassidy; Kleen, Greg J; Spendelow, Jacob S; Kopasz, John; Peterson, David; Garland, Nancy L; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C

    2012-12-18

    Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed.

  6. U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications

    PubMed Central

    Houchins, Cassidy; Kleen, Greg J.; Spendelow, Jacob S.; Kopasz, John; Peterson, David; Garland, Nancy L.; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C.

    2012-01-01

    Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed. PMID:24958432

  7. Development of high performance carbon composite catalyst for oxygen reduction reaction in PEM Proton Exchange Membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Nallathambi, Vijayadurga; Lee, Jong-Won; Kumaraguru, Swaminatha P.; Wu, Gang; Popov, Branko N.

    Highly active and stable carbon composite catalysts for oxygen reduction in PEM fuel cells were developed through the high-temperature pyrolysis of Co-Fe-N chelate complex, followed by the chemical post-treatment. A metal-free carbon catalyst was used as the support. The carbon composite catalyst showed an onset potential for oxygen reduction as high as 0.87 V (NHE) in H 2SO 4 solution, and generated less than 1% H 2O 2. The PEM fuel cell exhibited a current density as high as 0.27 A cm -2 at 0.6 V and 2.3 A cm -2 at 0.2 V for a catalyst loading of 6.0 mg cm -2. No significant performance degradation was observed over 480 h of continuous fuel cell operation with 2 mg cm -2 catalyst under a load of 200 mA cm -2 as evidenced by a resulting cell voltage of 0.32 V with a voltage decay rate of 80 μV h -1. Materials characterization studies indicated that the metal-nitrogen chelate complexes decompose at high pyrolysis temperatures above 800 °C, resulting in the formation of the metallic species. During the pyrolysis, the transition metals facilitate the incorporation of pyridinic and graphitic nitrogen groups into the carbon matrix, and the carbon surface doped with nitrogen groups is catalytically active for oxygen reduction.

  8. A novel strategy to construct high performance lithium-ion cells using one dimensional electrospun nanofibers, electrodes and separators

    NASA Astrophysics Data System (ADS)

    Aravindan, Vanchiappan; Sundaramurthy, Jayaraman; Kumar, Palaniswamy Suresh; Shubha, Nageswaran; Ling, Wong Chui; Ramakrishna, Seeram; Madhavi, Srinivasan

    2013-10-01

    We successfully demonstrated the performance of novel, one-dimensional electrospun nanofibers as cathode, anode and separator-cum-electrolyte in full-cell Li-ion configuration. The cathode, LiMn2O4 delivered excellent cycle life over 800 cycles at current density of 150 mA g-1 with capacity retention of ~93% in half-cell assembly (Li/LiMn2O4). Under the same current rate, the anode, anatase phase TiO2, rendered ~77% initial reversible capacity after 500 cycles in half-cell configuration (Li/TiO2). Gelled electrospun PVdF-HFP exhibits liquid-like conductivity of ~3.2 mS cm-1 at ambient temperature conditions (30 °C). For the first time, a full-cell is fabricated with enitrely electrospun one-dimensional materials by adjusting the mass loading of cathode with respect to anode in the presence of gelled PVdF-HFP membrane as a separator-cum-electrolyte. Full-cell LiMn2O4|gelled PVdF-HFP|TiO2 delivered good capacity characteristics and excellent cyclability with an operating potential of ~2.2 V at a current density of 150 mA g-1. Under harsh conditions (16 C rate), the full-cell showed a very stable capacity behavior with good calendar life. This clearly showed that electrospinning is an efficient technique for producing high performance electro-active materials to fabricate a high performance Li-ion assembly for commercialization without compromising the eco-friendliness and raw material cost.We successfully demonstrated the performance of novel, one-dimensional electrospun nanofibers as cathode, anode and separator-cum-electrolyte in full-cell Li-ion configuration. The cathode, LiMn2O4 delivered excellent cycle life over 800 cycles at current density of 150 mA g-1 with capacity retention of ~93% in half-cell assembly (Li/LiMn2O4). Under the same current rate, the anode, anatase phase TiO2, rendered ~77% initial reversible capacity after 500 cycles in half-cell configuration (Li/TiO2). Gelled electrospun PVdF-HFP exhibits liquid-like conductivity of ~3.2 mS cm-1 at

  9. High performance systems

    SciTech Connect

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  10. A novel strategy to construct high performance lithium-ion cells using one dimensional electrospun nanofibers, electrodes and separators.

    PubMed

    Aravindan, Vanchiappan; Sundaramurthy, Jayaraman; Kumar, Palaniswamy Suresh; Shubha, Nageswaran; Ling, Wong Chui; Ramakrishna, Seeram; Madhavi, Srinivasan

    2013-11-07

    We successfully demonstrated the performance of novel, one-dimensional electrospun nanofibers as cathode, anode and separator-cum-electrolyte in full-cell Li-ion configuration. The cathode, LiMn2O4 delivered excellent cycle life over 800 cycles at current density of 150 mA g(-1) with capacity retention of ~93% in half-cell assembly (Li/LiMn2O4). Under the same current rate, the anode, anatase phase TiO2, rendered ~77% initial reversible capacity after 500 cycles in half-cell configuration (Li/TiO2). Gelled electrospun PVdF-HFP exhibits liquid-like conductivity of ~3.2 mS cm(-1) at ambient temperature conditions (30 °C). For the first time, a full-cell is fabricated with enitrely electrospun one-dimensional materials by adjusting the mass loading of cathode with respect to anode in the presence of gelled PVdF-HFP membrane as a separator-cum-electrolyte. Full-cell LiMn2O4|gelled PVdF-HFP|TiO2 delivered good capacity characteristics and excellent cyclability with an operating potential of ∼2.2 V at a current density of 150 mA g(-1). Under harsh conditions (16 C rate), the full-cell showed a very stable capacity behavior with good calendar life. This clearly showed that electrospinning is an efficient technique for producing high performance electro-active materials to fabricate a high performance Li-ion assembly for commercialization without compromising the eco-friendliness and raw material cost.

  11. High-Performance Polymer Solar Cells Employing Rhodamines as Cathode Interfacial Layers.

    PubMed

    Li, Wang; Liu, Zhiyang; Yang, Rongjuan; Guan, Qian; Jiang, Weigang; Islam, Amjad; Lei, Tao; Hong, Ling; Peng, Ruixiang; Ge, Ziyi

    2017-08-16

    The development of simple and water-/alcohol-soluble interfacial materials is crucial for the cost-effective fabrication process of polymer solar cells (PSCs). Herein, highly efficient PSCs are reported employing water-/alcohol-soluble and low-cost rhodamines as cathode interfacial layers (CILs). The results reveal that rhodamine-based CILs can reduce the work function of the Al cathode and simultaneously increase the open-circuit voltage, current density, fill factor, and power conversion efficiency (PCE) of PSCs. The solution-processed rhodamine-based PSCs demonstrated a remarkable PCE of 10.39%, which is one of the best efficiencies reported for thieno[3,4-b]thiophene/benzodithiophene:[6,6]-phenyl C71-butyric acid methyl ester-based PSCs so far. The efficiency is also 42.3% higher than that of the vacuum-deposited Ca-based device (PCE of 7.30%) and 21.5% higher than that of the complicated solution-processable polymeric electrolyte poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)]-based device (PCE of 8.55%). Notably, rhodamines are very economical and have been extensively used as dyes in industries. Our work indicates that rhodamines have shown a strong potential as CILs compared to their counterparts in the large-area fabrication process of PSCs.

  12. High-performance inverted polymer solar cells based on thin copper film

    NASA Astrophysics Data System (ADS)

    Luo, Guoping; Cheng, Xiaoping; He, Zhicai; Wu, Hongbin; Cao, Yong

    2015-01-01

    We report the fabrication of cost-effective indium-free polymer solar cells (PSCs) with an inverted structure that incorporates an ultrathin copper (Cu) film as a bottom cathode via thermal evaporation. The average optical transmittance of the 15-nm Cu coated glass substrate in the visible region of the spectrum was found to be around 80% with a highest value of 84.5%. The Cu electrode was modified by an interfacial layer of an alcohol-/water-soluble conjugated polymer, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) interlayer to ensure a very smooth surface. Upon the use of the PFN interfacial layer, the work function of Cu was decreased from 4.68 to 4.31 eV, which can form an Ohmic contact with photoactive layer and facilitate electrode transport and extraction. As a result, a power conversion efficiency of 3.6% was achieved when poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] and a [6,6]-phenyl C71-butyric acid methyl ester blend were utilized as the photoactive layers, demonstrating that the thermally evaporated Cu thin-film electrode can be a promising candidate to replace indium tin oxide for highly efficient PSCs.

  13. Cell viability and MRI performance of highly efficient polyol-coated magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Arteaga-Cardona, Fernando; Gutiérrez-García, Eric; Hidalgo-Tobón, Silvia; López-Vasquez, Ciro; Brito-Barrera, Yazmín A.; Flores-Tochihuitl, Julia; Angulo-Molina, Aracely; Reyes-Leyva, Julio R.; González-Rodríguez, Roberto; Coffer, Jeffery L.; Pal, Umapada; Diaz-Conti, Mario Pérez-Peña; Platas-Neri, Diana; Dies-Suarez, Pilar; Fonseca, Rebeca Sosa; Arias-Carrión, Oscar; Méndez-Rojas, Miguel A.

    2016-11-01

    This work aimed at determining conditions that would allow us to control the size of the NPs and create a system with characteristics apt for biomedical applications. We describe a comprehensive study on the synthesis and physical characterization of two highly sensitive sets of triethylene glycol (TREG) and polyethylene glycol (PEG)-coated superparamagnetic iron oxide nanoparticles (SPIONs) to be evaluated for use as magnetic resonance (MR) contrast agents. The ferrofluids demonstrated excellent colloidal stability in deionized water at pH 7.0 as indicated by dynamic light scattering (DLS) data. The magnetic relaxivities, r 2, were measured on a 1.5 T clinical MRI instrument. Values in the range from 205 to 257 mM-1 s-1 were obtained, varying proportionally to the SPIONs' sizes and coating nature. Further in vitro cell viability tests and in vivo biodistribution analyses of the intravenously administered nanoparticles showed that the prepared systems have good biocompatibility and migrate to several organs, mainly the meninges, spleen, and liver. Based on these results, our findings demonstrated the potential utility of these nanosystems as clinical contrast agents for MR imaging.

  14. Scattering effect of the high-index dielectric nanospheres for high performance hydrogenated amorphous silicon thin-film solar cells

    PubMed Central

    Yang, Zhenhai; Gao, Pingqi; Zhang, Cheng; Li, Xiaofeng; Ye, Jichun

    2016-01-01

    Dielectric nanosphere arrays are considered as promising light-trapping designs with the capability of transforming the freely propagated sunlight into guided modes. This kinds of designs are especially beneficial to the ultrathin hydrogenated amorphous silicon (a-Si:H) solar cells due to the advantages of using lossless material and easily scalable assembly. In this paper, we demonstrate numerically that the front-sided integration of high-index subwavelength titanium dioxide (TiO2) nanosphere arrays can significantly enhance the light absorption in 100 nm-thick a-Si:H thin films and thus the power conversion efficiencies (PCEs) of related solar cells. The main reason behind is firmly attributed to the strong scattering effect excited by TiO2 nanospheres in the whole waveband, which contributes to coupling the light into a-Si:H layer via two typical ways: 1) in the short-waveband, the forward scattering of TiO2 nanospheres excite the Mie resonance, which focuses the light into the surface of the a-Si:H layer and thus provides a leaky channel; 2) in the long-waveband, the transverse waveguided modes caused by powerful scattering effectively couple the light into almost the whole active layer. Moreover, the finite-element simulations demonstrate that photocurrent density (Jph) can be up to 15.01 mA/cm2, which is 48.76% higher than that of flat system. PMID:27455911

  15. Scattering effect of the high-index dielectric nanospheres for high performance hydrogenated amorphous silicon thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Yang, Zhenhai; Gao, Pingqi; Zhang, Cheng; Li, Xiaofeng; Ye, Jichun

    2016-07-01

    Dielectric nanosphere arrays are considered as promising light-trapping designs with the capability of transforming the freely propagated sunlight into guided modes. This kinds of designs are especially beneficial to the ultrathin hydrogenated amorphous silicon (a-Si:H) solar cells due to the advantages of using lossless material and easily scalable assembly. In this paper, we demonstrate numerically that the front-sided integration of high-index subwavelength titanium dioxide (TiO2) nanosphere arrays can significantly enhance the light absorption in 100 nm-thick a-Si:H thin films and thus the power conversion efficiencies (PCEs) of related solar cells. The main reason behind is firmly attributed to the strong scattering effect excited by TiO2 nanospheres in the whole waveband, which contributes to coupling the light into a-Si:H layer via two typical ways: 1) in the short-waveband, the forward scattering of TiO2 nanospheres excite the Mie resonance, which focuses the light into the surface of the a-Si:H layer and thus provides a leaky channel; 2) in the long-waveband, the transverse waveguided modes caused by powerful scattering effectively couple the light into almost the whole active layer. Moreover, the finite-element simulations demonstrate that photocurrent density (Jph) can be up to 15.01 mA/cm2, which is 48.76% higher than that of flat system.

  16. Scattering effect of the high-index dielectric nanospheres for high performance hydrogenated amorphous silicon thin-film solar cells.

    PubMed

    Yang, Zhenhai; Gao, Pingqi; Zhang, Cheng; Li, Xiaofeng; Ye, Jichun

    2016-07-26

    Dielectric nanosphere arrays are considered as promising light-trapping designs with the capability of transforming the freely propagated sunlight into guided modes. This kinds of designs are especially beneficial to the ultrathin hydrogenated amorphous silicon (a-Si:H) solar cells due to the advantages of using lossless material and easily scalable assembly. In this paper, we demonstrate numerically that the front-sided integration of high-index subwavelength titanium dioxide (TiO2) nanosphere arrays can significantly enhance the light absorption in 100 nm-thick a-Si:H thin films and thus the power conversion efficiencies (PCEs) of related solar cells. The main reason behind is firmly attributed to the strong scattering effect excited by TiO2 nanospheres in the whole waveband, which contributes to coupling the light into a-Si:H layer via two typical ways: 1) in the short-waveband, the forward scattering of TiO2 nanospheres excite the Mie resonance, which focuses the light into the surface of the a-Si:H layer and thus provides a leaky channel; 2) in the long-waveband, the transverse waveguided modes caused by powerful scattering effectively couple the light into almost the whole active layer. Moreover, the finite-element simulations demonstrate that photocurrent density (Jph) can be up to 15.01 mA/cm(2), which is 48.76% higher than that of flat system.

  17. Ultra-thin silicon solar cells for high performance panel applications

    NASA Technical Reports Server (NTRS)

    Gay, C. F.

    1978-01-01

    Solar cells have been fabricated which achieved the highest power to mass ratios and radiation stability yet reported for silicon devices. The thinnest cells (.04 mm) had initial efficiencies in excess of 2 watts per gram (AMO) and 1.7 watts per gram after an irradiation of 1 x 10 to the 15th equivalent 1 MeV electrons per square centimeter. The cells have been successfully interconnected by welding and filtered using a FEP bonded, ceria-doped microsheet of six mil thickness. Handling losses during cell manufacture and panel assembly may be minimized through the use of an integral reinforcing perimeter or ribs which remove almost all restrictions on cell thickness and area. Such a cell is typically composed of a main section which can be as thin as 0.015 mm and is supported at the edge by a thicker border (0.20 mm) of silicon.

  18. Ultra-thin silicon solar cells for high performance panel applications

    NASA Technical Reports Server (NTRS)

    Gay, C. F.

    1978-01-01

    Solar cells have been fabricated which achieved the highest power to mass ratios and radiation stability yet reported for silicon devices. The thinnest cells (.04 mm) had initial efficiencies in excess of 2 watts per gram (AMO) and 1.7 watts per gram after an irradiation of 1 x 10 to the 15th equivalent 1 MeV electrons per square centimeter. The cells have been successfully interconnected by welding and filtered using a FEP bonded, ceria-doped microsheet of six mil thickness. Handling losses during cell manufacture and panel assembly may be minimized through the use of an integral reinforcing perimeter or ribs which remove almost all restrictions on cell thickness and area. Such a cell is typically composed of a main section which can be as thin as 0.015 mm and is supported at the edge by a thicker border (0.20 mm) of silicon.

  19. Toward High-Performance Organic-Inorganic Hybrid Solar Cells: Bringing Conjugated Polymers and Inorganic Nanocrystals in Close Contact.

    PubMed

    He, Ming; Qiu, Feng; Lin, Zhiqun

    2013-06-06

    Organic-inorganic hybrid solar cells composed of conjugated polymers (CPs) and inorganic nanocrystal (NC) semiconductors have garnered considerable attention as a potential alternative to traditional silicon solar cells due to the capacity of producing high-efficiency solar energy in a cost-effective manner. The combination of advantageous characteristics of CPs and NCs enables the construction of nanostructured high-performance, lightweight, flexible, large-area, and low-cost hybrid solar cells. However, it remains a grand challenge to control the film morphology and interfacial structure of such organic/inorganic semiconductor blends on the nanoscale. In this Perspective, we highlight the strategies of implementing close contact between CPs and NCs by tailoring the colloidal synthesis, the coordination reaction, and the chemical modification of CPs. As such, they offer promising opportunities for rationally controlling the phase separation between electron-donating CPs and electron-accepting NCs, increasing the interfacial areas between them, enhancing their electronic interaction, and thus substantially promoting the photovoltaic performance of the resulting organic-inorganic hybrid solar cells.

  20. High Performance Polymers

    NASA Technical Reports Server (NTRS)

    Venumbaka, Sreenivasulu R.; Cassidy, Patrick E.

    2003-01-01

    This report summarizes results from research on high performance polymers. The research areas proposed in this report include: 1) Effort to improve the synthesis and to understand and replicate the dielectric behavior of 6HC17-PEK; 2) Continue preparation and evaluation of flexible, low dielectric silicon- and fluorine- containing polymers with improved toughness; and 3) Synthesis and characterization of high performance polymers containing the spirodilactam moiety.

  1. MoS2 Quantum Dots with a Tunable Work Function for High-Performance Organic Solar Cells.

    PubMed

    Xing, Wang; Chen, Yusheng; Wang, Xinlong; Lv, Lei; Ouyang, Xinhua; Ge, Ziyi; Huang, Hui

    2016-10-12

    An efficient hole extraction layer (HEL) is critical to achieve high-performance organic solar cells (OSCs). In this study, we developed a pinhole-free and efficient HEL based on MoS2 quantum dots (QDs) combined with UV-ozone (UVO) treatment. The optophysical properties and morphology of MoS2 QDs and their photovoltaic performance are investigated. The results showed that MoS2 QDs can form homogeneous films and can be applied as an interfacial layer not only for donors with shallow highest occupied molecular orbital (HOMO) but also for those with deep HOMO energy levels after UVO treatment (O-MoS2 QDs). The solar cells based on O-MoS2 QDs yield a power conversion efficiency (PCE) of 8.66%, which is 71% and 12% higher than those of the OSCs with pristine MoS2 QD and O-MoS2 nanosheets, respectively, and the highest PCEs for OSCs containing MoS2 materials. Furthermore, the stability of solar cells based on MoS2 QDs is greatly improved in comparison with state-of-the-art PEDOT:PSS. These results demonstrate the great potential of O-MoS2 QDs as an efficient HEL for high-performance OSCs.

  2. Enhanced performance and stability of high temperature proton exchange membrane fuel cell by incorporating zirconium hydrogen phosphate in catalyst layer

    NASA Astrophysics Data System (ADS)

    Barron, Olivia; Su, Huaneng; Linkov, Vladimir; Pollet, Bruno G.; Pasupathi, Sivakumar

    2015-03-01

    Zirconium hydrogen phosphate (ZHP) together with polytetrafluoroethylene (PTFE) polymer binder is incorporated into the catalyst layers (CLs) of ABPBI (poly(2,5-benzimidazole))-based high temperature polymer electrolyte membrane fuel cell (HT-PEMFCs) to improve its performance and durability. The influence of ZHP content (normalised with respect to dry PTFE) on the CL properties are structurally characterised by scanning electron microscopy (SEM) and mercury intrusion porosimetry. Electrochemical analyses of the resultant membrane electrode assemblies (MEAs) are performed by recording polarisation curves and impedance spectra at 160 °C, ambient pressure and humidity. The result show that a 30 wt.% ZHP/PTFE content in the CL is optimum for improving fuel cell performance, the resultant MEA delivers a peak power of 592 mW cm-2 at a cell voltage of 380 mV. Electrochemical impedance spectra (EIS) indicate that 30% ZHP in the CL can increase the proton conductivity compared to the pristine PTFE-gas diffusion electrode (GDE). A short term stability test (∼500 h) on the 30 wt.% ZHP/PTFE-GDE shows a remarkable high durability with a degradation rate as low as ∼19 μV h-1 at 0.2 A cm-2, while 195 μV h-1 was obtained for the pristine GDE.

  3. Realization of Both High-Performance and Enhanced Durability of Fuel Cells: Pt-Exoskeleton Structure Electrocatalysts.

    PubMed

    Kim, Ok-Hee; Cho, Yoon-Hwan; Jeon, Tae-Yeol; Kim, Jung Won; Cho, Yong-Hun; Sung, Yung-Eun

    2015-07-01

    Core-shell structure nanoparticles have been the subject of many studies over the past few years and continue to be studied as electrocatalysts for fuel cells. Therefore, many excellent core-shell catalysts have been fabricated, but few studies have reported the real application of these catalysts in a practical device actual application. In this paper, we demonstrate the use of platinum (Pt)-exoskeleton structure nanoparticles as cathode catalysts with high stability and remarkable Pt mass activity and report the outstanding performance of these materials when used in membrane-electrode assemblies (MEAs) within a polymer electrolyte membrane fuel cell. The stability and degradation characteristics of these materials were also investigated in single cells in an accelerated degradation test using load cycling, which is similar to the drive cycle of a polymer electrolyte membrane fuel cell used in vehicles. The MEAs with Pt-exoskeleton structure catalysts showed enhanced performance throughout the single cell test and exhibited improved degradation ability that differed from that of a commercial Pt/C catalyst.

  4. Reconfiguration of lithium sulphur batteries: "Enhancement of Li-S cell performance by employing a highly porous conductive separator coating"

    NASA Astrophysics Data System (ADS)

    Stoeck, Ulrich; Balach, Juan; Klose, Markus; Wadewitz, Daniel; Ahrens, Eike; Eckert, Jürgen; Giebeler, Lars

    2016-03-01

    Li-S batteries are an emerging technology and the most promising successor of current lithium ion technology. While there is great perspective in terms of superior theoretical specific capacity and energy density great challenges have to be addressed. One major challenge, severely limiting cycle performance and capacity retention, is the shuttling of polysulphide species. In this contribution we show a reconfiguration of the usual Li-S cell. Instead of generating a carbon/sulphur composite by melt infiltration a highly porous, conductive nitrogen-rich carbon material (TNC) is coated onto a commercial polypropylene separator foil. The thin conductive coating of TNC on the separator enables the application of very simple sulphur/carbon black cathodes. Because the melt infiltration of sulphur in a porous host material becomes unnecessary the electrode processing is significantly simplified. The specific capacity and cycling stability of reconfigurated cells are both improved significantly compared to the performance of a standard cell setup using a pristine separator. At a constant charging rate of C/5 cells with modified separator showed 2.5 times higher residual capacity (1016 mAh g-1) than cells with pristine separator (405 mAh g-1).

  5. Highly Conductive PEDOT:PSS Transparent Hole Transporting Layer with Solvent Treatment for High Performance Silicon/Organic Hybrid Solar Cells.

    PubMed

    Li, Qingduan; Yang, Jianwei; Chen, Shuangshuang; Zou, Jizhao; Xie, Weiguang; Zeng, Xierong

    2017-08-23

    Efficient Si/organic hybrid solar cells were fabricated with dimethyl sulfoxide (DMSO) and surfactant-doped poly(3,4-ethylenedioxythiophene): polystyrene (PEDOT:PSS). A post-treatment on PEDOT:PSS films with polar solvent was performed to increase the device performance. We found that the performance of hybrid solar cells increase with the polarity of solvent. A high conductivity of 1105 S cm(- 1) of PEDOT:PSS was achieved by adopting methanol treatment, and the best efficiency of corresponding hybrid solar cells reaches 12.22%. X-ray photoelectron spectroscopy (XPS) and RAMAN spectroscopy were utilized to conform to component changes of PEDOT:PSS films after solvent treatment. It was found that the removal of the insulator PSS from the film and the conformational changes are the determinants for the device performance enhancement. Electrochemical impedance spectroscopy (EIS) was used to investigate the recombination resistance and capacitance of methanol-treated and untreated hybrid solar cells, indicating that methanol-treated devices had a larger recombination resistance and capacitance. Our findings bring a simple and efficient way for improving the performance of hybrid solar cell.

  6. Highly Conductive PEDOT:PSS Transparent Hole Transporting Layer with Solvent Treatment for High Performance Silicon/Organic Hybrid Solar Cells

    NASA Astrophysics Data System (ADS)

    Li, Qingduan; Yang, Jianwei; Chen, Shuangshuang; Zou, Jizhao; Xie, Weiguang; Zeng, Xierong

    2017-08-01

    Efficient Si/organic hybrid solar cells were fabricated with dimethyl sulfoxide (DMSO) and surfactant-doped poly(3,4-ethylenedioxythiophene): polystyrene (PEDOT:PSS). A post-treatment on PEDOT:PSS films with polar solvent was performed to increase the device performance. We found that the performance of hybrid solar cells increase with the polarity of solvent. A high conductivity of 1105 S cm- 1 of PEDOT:PSS was achieved by adopting methanol treatment, and the best efficiency of corresponding hybrid solar cells reaches 12.22%. X-ray photoelectron spectroscopy (XPS) and RAMAN spectroscopy were utilized to conform to component changes of PEDOT:PSS films after solvent treatment. It was found that the removal of the insulator PSS from the film and the conformational changes are the determinants for the device performance enhancement. Electrochemical impedance spectroscopy (EIS) was used to investigate the recombination resistance and capacitance of methanol-treated and untreated hybrid solar cells, indicating that methanol-treated devices had a larger recombination resistance and capacitance. Our findings bring a simple and efficient way for improving the performance of hybrid solar cell.

  7. High-performance aqueous/organic dye-sensitized solar cells based on sensitizers containing triethylene oxide methyl ether.

    PubMed

    Lin, Ryan Yeh-Yung; Wu, Feng-Ling; Li, Chun-Ting; Chen, Pei-Yu; Ho, Kuo-Chuan; Lin, Jiann T

    2015-08-10

    Metal-free dyes (EO1 to EO4) containing the hydrophilic triethylene oxide methyl ether (TEOME) unit in the spacer have been synthesized and used in dye-sensitized solar cells (DSSCs). Efficient lithium-ion trapping by TEOME results in improved open-circuit voltage (VOC ), leading to excellent conversion efficiency of the cells, ranging from 9.02 to 9.98 % with I(-) /I3 (-) electrolyte in acetonitrile under AM 1.5 illumination. The TEOME unit also enhances the wettability of the dye molecules for application in aqueous-based DSSCs. Aqueous-based DSSCs with a dual TEMPO/iodide electrolyte exhibit high VOC values (0.80-0.88 V) and very promising cell performances of up to 5.97 %.

  8. High-performance single CdS nanowire (nanobelt) Schottky junction solar cells with Au/graphene Schottky electrodes.

    PubMed

    Ye, Yu; Dai, Yu; Dai, Lun; Shi, Zujin; Liu, Nan; Wang, Fei; Fu, Lei; Peng, Ruomin; Wen, Xiaonan; Chen, Zhijian; Liu, Zhongfan; Qin, Guogang

    2010-12-01

    High-performance single CdS nanowire (NW) as well as nanobelt (NB) Schottky junction solar cells were fabricated. Au (5 nm)/graphene combined layers were used as the Schottky contact electrodes to the NWs (NBs). Typical as-fabricated NW solar cell shows excellent photovoltaic behavior with an open circuit voltage of ∼0.15 V, a short circuit current of ∼275.0 pA, and an energy conversion efficiency of up to ∼1.65%. The physical mechanism of the combined Schottky electrode was discussed. We attribute the prominent capability of the devices to the high-performance Schottky combined electrode, which has the merits of low series resistance, high transparency, and good Schottky contact to the CdS NW (NB). Besides, a promising site-controllable patterned graphene transfer method, which has the advantages of economizing graphene material and free from additional etching process, was demonstrated in this work. Our results suggest that semiconductor NWs (NBs) are promising materials for novel solar cells, which have potential application in integrated nano-optoelectronic systems.

  9. Acid-doped polymer nanofiber framework: Three-dimensional proton conductive network for high-performance fuel cells

    NASA Astrophysics Data System (ADS)

    Tanaka, Manabu; Takeda, Yasushi; Wakiya, Takeru; Wakamoto, Yuta; Harigaya, Kaori; Ito, Tatsunori; Tarao, Takashi; Kawakami, Hiroyoshi

    2017-02-01

    High-performance polymer electrolyte membranes (PEMs) with excellent proton conductivity, gas barrier property, and membrane stability are desired for future fuel cells. Here we report the development of PEMs based on our proposed new concept ;Nanofiber Framework (NfF).; The NfF composite membranes composed of phytic acid-doped polybenzimidazole nanofibers (PBINf) and Nafion matrix show higher proton conductivity than the recast-Nafion membrane without nanofibers. A series of analyses reveal the formation of three-dimensional network nanostructures to conduct protons and water effectively through acid-condensed layers at the interface of PBINf and Nafion matrix. In addition, the NfF composite membrane achieves high gas barrier property and distinguished membrane stability. The fuel cell performance by the NfF composite membrane, which enables ultra-thin membranes with their thickness less than 5 μm, is superior to that by the recast-Nafion membrane, especially at low relative humidity. Such NfF-based high-performance PEM will be accomplished not only by the Nafion matrix used in this study but also by other polymer electrolyte matrices for future PEFCs.

  10. High-Performance Organic Solar Cells Based on a Non-Fullerene Acceptor with a Spiro Core.

    PubMed

    Sun, Hua; Sun, Po; Zhang, Cong; Yang, Yingguo; Gao, Xingyu; Chen, Fei; Xu, Zongxiang; Chen, Zhi-Kuan; Huang, Wei

    2017-01-26

    Derived from perylenediimide (PDI) building blocks, 3D PDI molecules are considered as a type of promising structure to overcome molecular aggregation, thus improving the performance of organic solar cells. Herein, we report a novel PDI-based derivative, SCPDT-PDI4 , with four PDI units connected to a unique spiro core. Attributed to this novel molecular design, SCPDT-PDI4 exhibits a rigid 3D structure, in which the aggregation tendency of PDI chromophores could be effectively attenuated. Additionally, strong intramolecular charge transfer and high charge mobility are achieved due to the well-conjugated structure and electron-rich property of SCPDT. Therefore, fullerene-free organic solar cells based on SCPDT-PDI4 and PTB7-Th achieve a remarkable high efficiency of 7.11 %. Such an excellent result demonstrates the opportunity of SCPDT to be a promising building block for non-fullerene acceptors.

  11. Room-temperature, solution-processable organic electron extraction layer for high-performance planar heterojunction perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Jong H.; Chueh, Chu-Chen; Williams, Spencer T.; Jen, Alex K.-Y.

    2015-10-01

    In this work, we describe a room-temperature, solution-processable organic electron extraction layer (EEL) for high-performance planar heterojunction perovskite solar cells (PHJ PVSCs). This EEL is composed of a bilayered fulleropyrrolidinium iodide (FPI)-polyethyleneimine (PEIE) and PC61BM, which yields a promising power conversion efficiency (PCE) of 15.7% with insignificant hysteresis. We reveal that PC61BM can serve as a surface modifier of FPI-PEIE to simultaneously facilitate the crystallization of perovskite and the charge extraction at FPI-PEIE/CH3NH3PbI3 interface. Furthermore, the FPI-PEIE can also tune the work function of ITO and dope PC61BM to promote the efficient electron transport between ITO and PC61BM. Based on the advantages of room-temperature processability and decent electrical property of FPI-PEIE/PC61BM EEL, a high-performance flexible PVSC with a PCE ~10% is eventually demonstrated. This study shows the potential of low-temperature processed organic EEL to replace transition metal oxide-based interlayers for highly printing compatible PVSCs with high-performance.In this work, we describe a room-temperature, solution-processable organic electron extraction layer (EEL) for high-performance planar heterojunction perovskite solar cells (PHJ PVSCs). This EEL is composed of a bilayered fulleropyrrolidinium iodide (FPI)-polyethyleneimine (PEIE) and PC61BM, which yields a promising power conversion efficiency (PCE) of 15.7% with insignificant hysteresis. We reveal that PC61BM can serve as a surface modifier of FPI-PEIE to simultaneously facilitate the crystallization of perovskite and the charge extraction at FPI-PEIE/CH3NH3PbI3 interface. Furthermore, the FPI-PEIE can also tune the work function of ITO and dope PC61BM to promote the efficient electron transport between ITO and PC61BM. Based on the advantages of room-temperature processability and decent electrical property of FPI-PEIE/PC61BM EEL, a high-performance flexible PVSC with a PCE ~10% is

  12. High Performing Ternary Solar Cells through Förster Resonance Energy Transfer between Nonfullerene Acceptors.

    PubMed

    Yang, Lei; Gu, Wenxing; Hong, Ling; Mi, Yang; Liu, Feng; Liu, Ming; Yang, Yufei; Sharma, Bigyan; Liu, Xinfeng; Huang, Hui

    2017-08-16

    Nonradiative Förster resonance energy transfer (FRET) is an important mechanism of organic solar cells, which can improve the exciton migration over a long distance, resulting in improvement of efficiency of solar cells. However, the current observations of FRET are very limited, and the efficiencies are less than 9%. In this study, FRET effect was first observed between two nonfullerene acceptors in ternary solar cells, which improved both the absorption range and exciton harvesting, leading to the dramatic enhancement in the short circuit current and power conversion efficiency. Moreover, this strategy is proved to be a versatile platform for conjugated polymers with different bandgaps, resulting in a remarkable efficiency of 10.4%. These results demonstrated a novel method to enhance the efficiency of organic soar cells.

  13. High-performance analysis of single interphase cells with custom DNA probes spanning translocation break points

    NASA Astrophysics Data System (ADS)

    Weier, Heinz-Ulli G.; Munne, S.; Lersch, Robert A.; Marquez, C.; Wu, J.; Pedersen, Roger A.; Fung, Jingly

    1999-06-01

    The chromatin organization of interphase cell nuclei, albeit an object of intense investigation, is only poorly understood. In the past, this has hampered the cytogenetic analysis of tissues derived from specimens where only few cells were actively proliferating or a significant number of metaphase cells could be obtained by induction of growth. Typical examples of such hard to analyze cell systems are solid tumors, germ cells and, to a certain extent, fetal cells such as amniocytes, blastomeres or cytotrophoblasts. Balanced reciprocal translocations that do not disrupt essential genes and thus do not led to disease symptoms exit in less than one percent of the general population. Since the presence of translocations interferes with homologue pairing in meiosis, many of these individuals experience problems in their reproduction, such as reduced fertility, infertility or a history of spontaneous abortions. The majority of translocation carriers enrolled in our in vitro fertilization (IVF) programs carry simple translocations involving only two autosomes. While most translocations are relatively easy to spot in metaphase cells, the majority of cells biopsied from embryos produced by IVF are in interphase and thus unsuitable for analysis by chromosome banding or FISH-painting. We therefore set out to analyze single interphase cells for presence or absence of specific translocations. Our assay, based on fluorescence in situ hybridization (FISH) of breakpoint-spanning DNA probes, detects translocations in interphase by visual microscopic inspection of hybridization domains. Probes are prepared so that they span a breakpoint and cover several hundred kb of DNA adjacent to the breakpoint. On normal chromosomes, such probes label a contiguous stretch of DNA and produce a single hybridization domain per chromosome in interphase cells. The translocation disrupts the hybridization domain and the resulting two fragments appear as physically separated hybridization domains in

  14. Self-assembled plasmonic electrodes for high-performance organic photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Luhman, Wade A.; Hoon Lee, Si; Johnson, Timothy W.; Holmes, Russell J.; Oh, Sang-Hyun

    2011-09-01

    We investigate thin Ag films incorporating plasmonic nanohole arrays as transparent conducting electrodes for organic photovoltaic cells. Plasmonic electrodes are fabricated using nanosphere lithography to create hexagonal nanohole arrays over centimeter-sized areas. Devices constructed using a nanopatterned Ag anode show power conversion efficiencies that exceed those of devices constructed on conventional indium-tin-oxide, independent of light polarization. In comparison to cells constructed on unpatterned Ag, the power conversion efficiency is noted to double with patterning.

  15. Fabrication Method for Laboratory-Scale High-Performance Membrane Electrode Assemblies for Fuel Cells.

    PubMed

    Sassin, Megan B; Garsany, Yannick; Gould, Benjamin D; Swider-Lyons, Karen E

    2017-01-03

    Custom catalyst-coated membranes (CCMs) and membrane electrode assemblies (MEAs) are necessary for the evaluation of advanced electrocatalysts, gas diffusion media (GDM), ionomers, polymer electrolyte membranes (PEMs), and electrode structures designed for use in next-generation fuel cells, electrolyzers, or flow batteries. This Feature provides a reliable and reproducible fabrication protocol for laboratory scale (10 cm(2)) fuel cells based on ultrasonic spray deposition of a standard Pt/carbon electrocatalyst directly onto a perfluorosulfonic acid PEM.

  16. High performance thylakoid bio-solar cell using laccase enzymatic biocathodes.

    PubMed

    Rasmussen, Michelle; Shrier, Alexander; Minteer, Shelley D

    2013-06-21

    Thylakoid membranes have previously been used for electrochemical solar energy conversion, but the current output and open circuit voltage are low, in part due to limitations of the cathode. In this paper, a thylakoid bioanode and laccase biocathode were combined in the construction of a bio-solar cell capable of light-induced generation of electrical power. This two-compartment cell showed a greater than 5-fold increase in short circuit current density and an open circuit voltage 0.275 V larger than that of a thylakoid bio-solar cell incorporating an air-breathing Pt cathode. The electrodes were then tested in several solutions of varying pH to evaluate the possibility of constructing a compartment-less bio-solar cell. This membrane-less cell, operating at pH 5.5, generated a short circuit photocurrent density of 14.0 ± 1.8 μA cm(-2) which is 25% larger than the two-compartment cell and a similar open circuit voltage of 0.720 ± 0.018 V.

  17. High performance polymer electrolytes based on main and side chain pyridine aromatic polyethers for high and medium temperature proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Geormezi, M.; Chochos, C. L.; Gourdoupi, N.; Neophytides, S. G.; Kallitsis, J. K.

    Novel aromatic polyether type copolymers bearing side chain polar pyridine rings as well as combination of main and side chain pyridine units have been evaluated as potential polymer electrolytes for proton exchange membrane fuel cells (PEMFCs). The advanced chemical and physicochemical properties of these new polymers with their high oxidative stability, mechanical integrity and high glass transition temperatures (T g's up to 270 °C) and decomposition temperatures (T d's up to 480 °C) make them promising candidates for high and medium temperature proton exchange membranes in fuel cells. These copolymers exhibit adequate proton conductivities up to 0.08 S cm -1 even at moderate phosphoric acid doping levels. An optimized terpolymer chemical structure has been developed, which has been effectively tested as high temperature phosphoric acid imbibed polymer electrolyte. MEA prepared out of the novel terpolymer chemical structure is approaching state of the art fuel cell operating performance (135 mW cm -2 with electrical efficiency 45%) at high temperatures (150-180 °C) despite the low phosphoric acid content (<200 wt%) and the low platinum loading (ca. 0.7 mg cm -2). Durability tests were performed affording stable performance for more than 1000 h.

  18. High-Performance Solution-Processed Non-Fullerene Organic Solar Cells Based on Selenophene-Containing Perylene Bisimide Acceptor.

    PubMed

    Meng, Dong; Sun, Dan; Zhong, Chengmei; Liu, Tao; Fan, Bingbing; Huo, Lijun; Li, Yan; Jiang, Wei; Choi, Hyosung; Kim, Taehyo; Kim, Jin Young; Sun, Yanming; Wang, Zhaohui; Heeger, Alan J

    2016-01-13

    Non-fullerene acceptors have recently attracted tremendous interest because of their potential as alternatives to fullerene derivatives in bulk heterojunction organic solar cells. However, the power conversion efficiencies (PCEs) have lagged far behind those of the polymer/fullerene system, mainly because of the low fill factor (FF) and photocurrent. Here we report a novel perylene bisimide (PBI) acceptor, SdiPBI-Se, in which selenium atoms were introduced into the perylene core. With a well-established wide-band-gap polymer (PDBT-T1) as the donor, a high efficiency of 8.4% with an unprecedented high FF of 70.2% is achieved for solution-processed non-fullerene organic solar cells. Efficient photon absorption, high and balanced charge carrier mobility, and ultrafast charge generation processes in PDBT-T1:SdiPBI-Se films account for the high photovoltaic performance. Our results suggest that non-fullerene acceptors have enormous potential to rival or even surpass the performance of their fullerene counterparts.

  19. Ternary PtRuPd/C catalyst for high-performance, low-temperature direct dimethyl ether fuel cells

    SciTech Connect

    Dumont, Joseph Henry; Martinez, Ulises; Chung, Hoon T.; Zelenay, Piotr

    2016-08-19

    Here, dimethyl ether (DME) is a promising alternative fuel option for direct-feed low-temperature fuel cells. Until recently, DME had not received the same attention as alcohol fuels, such as methanol or ethanol, despite its notable advantages. These advantages include a high theoretical open-cell voltage (1.18 V at 25 °C) that is similar to that of methanol (1.21 V), much lower toxicity than methanol, and no need for the carbon–carbon bond scission that is needed in ethanol oxidation. DME is biodegradable, has a higher energy content than methanol (8.2 vs. 6.1 kWh kg–1), and, like methanol, can be synthesized from recycled carbon dioxide. Although the performance of direct DME fuel cells (DDMEFCs) has progressed over the past few years, DDMEFCs have not been viewed as fully viable. In this work, we report much improved performance from the ternary Pt55Ru35Pd10/C anode catalyst, allowing DDMEFCs to compete directly with direct methanol fuel cells (DMFCs). We also report results involving binary Pt alloys as reference catalysts and an in situ infrared electrochemical study to better understand the mechanism of DME electro-oxidation on ternary PtRuPd/C catalysts.

  20. Ternary PtRuPd/C catalyst for high-performance, low-temperature direct dimethyl ether fuel cells

    DOE PAGES

    Dumont, Joseph Henry; Martinez, Ulises; Chung, Hoon T.; ...

    2016-08-19

    Here, dimethyl ether (DME) is a promising alternative fuel option for direct-feed low-temperature fuel cells. Until recently, DME had not received the same attention as alcohol fuels, such as methanol or ethanol, despite its notable advantages. These advantages include a high theoretical open-cell voltage (1.18 V at 25 °C) that is similar to that of methanol (1.21 V), much lower toxicity than methanol, and no need for the carbon–carbon bond scission that is needed in ethanol oxidation. DME is biodegradable, has a higher energy content than methanol (8.2 vs. 6.1 kWh kg–1), and, like methanol, can be synthesized from recycledmore » carbon dioxide. Although the performance of direct DME fuel cells (DDMEFCs) has progressed over the past few years, DDMEFCs have not been viewed as fully viable. In this work, we report much improved performance from the ternary Pt55Ru35Pd10/C anode catalyst, allowing DDMEFCs to compete directly with direct methanol fuel cells (DMFCs). We also report results involving binary Pt alloys as reference catalysts and an in situ infrared electrochemical study to better understand the mechanism of DME electro-oxidation on ternary PtRuPd/C catalysts.« less

  1. Ternary PtRuPd/C catalyst for high-performance, low-temperature direct dimethyl ether fuel cells

    SciTech Connect

    Dumont, Joseph Henry; Martinez, Ulises; Chung, Hoon T.; Zelenay, Piotr

    2016-08-19

    Here, dimethyl ether (DME) is a promising alternative fuel option for direct-feed low-temperature fuel cells. Until recently, DME had not received the same attention as alcohol fuels, such as methanol or ethanol, despite its notable advantages. These advantages include a high theoretical open-cell voltage (1.18 V at 25 °C) that is similar to that of methanol (1.21 V), much lower toxicity than methanol, and no need for the carbon–carbon bond scission that is needed in ethanol oxidation. DME is biodegradable, has a higher energy content than methanol (8.2 vs. 6.1 kWh kg–1), and, like methanol, can be synthesized from recycled carbon dioxide. Although the performance of direct DME fuel cells (DDMEFCs) has progressed over the past few years, DDMEFCs have not been viewed as fully viable. In this work, we report much improved performance from the ternary Pt55Ru35Pd10/C anode catalyst, allowing DDMEFCs to compete directly with direct methanol fuel cells (DMFCs). We also report results involving binary Pt alloys as reference catalysts and an in situ infrared electrochemical study to better understand the mechanism of DME electro-oxidation on ternary PtRuPd/C catalysts.

  2. A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation

    PubMed Central

    Lan, Rong; Tao, Shanwen

    2016-01-01

    In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm2 are achieved when biomass—bamboo charcoal and wood, respectively–is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required CO32− or CO42− ions for continuous operation. The dissolved O2− ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency. PMID:27540588

  3. Fast stack activation procedure and effective long-term storage for high-performance polymer electrolyte membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Yang, Seung Yong; Seo, Dong-Jun; Kim, Myeong-Ri; Seo, Min Ho; Hwang, Sun-Mi; Jung, Yong-Min; Kim, Beom-Jun; Yoon, Young-Gi; Han, Byungchan; Kim, Tae-Young

    2016-10-01

    Time-saving stack activation and effective long-term storage are one of most important issues that must be resolved for the commercialization of polymer electrolyte membrane fuel cell (PEMFC). Herein, we developed the cost-effective stack activation method to finish the whole activation within 30 min and the long-term storage method by using humidified N2 without any significant decrease in cell's performance for 30 days. Specifically, the pre-activation step with the direct injection of DI water into the stack and storage at 65 or 80 °C for 2 h increases the distinctive phase separation between the hydrophobic and hydrophilic regions in Nafion membrane, which significantly reduces the total activation time within 30 min. Additionally, the long-term storage with humidified N2 has no effect on the Pt oxidation and drying of Nafion membrane for 30 days due to its exergonic reaction in the cell. As a result, the high water content in Nafion membrane and the decrease of Pt oxidation are the critical factors that have a strong influence on the activation and long-term storage for high-performance PEMFC.

  4. A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation.

    PubMed

    Lan, Rong; Tao, Shanwen

    2016-08-01

    In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm(2) are achieved when biomass-bamboo charcoal and wood, respectively-is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required [Formula: see text] or [Formula: see text] ions for continuous operation. The dissolved [Formula: see text] ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency.

  5. High Performance PbS Quantum Dot/Graphene Hybrid Solar Cell with Efficient Charge Extraction

    PubMed Central

    2016-01-01

    Hybrid colloidal quantum dot (CQD) solar cells are fabricated from multilayer stacks of lead sulfide (PbS) CQD and single layer graphene (SG). The inclusion of graphene interlayers is shown to increase power conversion efficiency by 9.18%. It is shown that the inclusion of conductive graphene enhances charge extraction in devices. Photoluminescence shows that graphene quenches emission from the quantum dot suggesting spontaneous charge transfer to graphene. CQD photodetectors exhibit increased photoresponse and improved transport properties. We propose that the CQD/SG hybrid structure is a route to make CQD thin films with improved charge extraction, therefore resulting in improved solar cell efficiency. PMID:27213219

  6. High Performance PbS Quantum Dot/Graphene Hybrid Solar Cell with Efficient Charge Extraction.

    PubMed

    Kim, Byung-Sung; Neo, Darren C J; Hou, Bo; Park, Jong Bae; Cho, Yuljae; Zhang, Nanlin; Hong, John; Pak, Sangyeon; Lee, Sanghyo; Sohn, Jung Inn; Assender, Hazel E; Watt, Andrew A R; Cha, SeungNam; Kim, Jong Min

    2016-06-08

    Hybrid colloidal quantum dot (CQD) solar cells are fabricated from multilayer stacks of lead sulfide (PbS) CQD and single layer graphene (SG). The inclusion of graphene interlayers is shown to increase power conversion efficiency by 9.18%. It is shown that the inclusion of conductive graphene enhances charge extraction in devices. Photoluminescence shows that graphene quenches emission from the quantum dot suggesting spontaneous charge transfer to graphene. CQD photodetectors exhibit increased photoresponse and improved transport properties. We propose that the CQD/SG hybrid structure is a route to make CQD thin films with improved charge extraction, therefore resulting in improved solar cell efficiency.

  7. A Green Route to Conjugated Polyelectrolyte Interlayers for High-Performance Solar Cells.

    PubMed

    Subbiah, Jegadesan; Mitchell, Valerie D; Hui, Nicholas K C; Jones, David J; Wong, Wallace W H

    2017-03-03

    Synthesis of fluorene-based conjugated polyelectrolytes was achieved via Suzuki polycondensation in water and completely open to air. The polyelectrolytes were conveniently purified by dialysis and analysis of the materials showed properties expected for fluorene-based conjugated polyelectrolytes. The materials were then employed in solar cell devices as an interlayer in conjunction with ZnO. The double interlayer led to enhanced power conversion efficiency of 10.75 % and 15.1 % for polymer and perovskite solar cells, respectively.

  8. Binary-metal perovskites toward high-performance planar-heterojunction hybrid solar cells.

    PubMed

    Zuo, Fan; Williams, Spencer T; Liang, Po-Wei; Chueh, Chu-Chen; Liao, Chien-Yi; Jen, Alex K-Y

    2014-10-08

    A simple, low temperature solution process for Pb/Sn binary-metal perovskite planar-heterojunction solar cells is demonstrated. Sn inclusion substantially influences the band-gap, crystallization kinetics, and thin-film formation leading to a broadened light absorption and enhanced film coverage on ITO/PEDOT:PSS. As a result, the optimized device shows a PCE exceeding 10%, which is the best result for binary-metal perovskite solar cells so far. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Interface-designed Membranes with Shape-controlled Patterns for High-performance Polymer Electrolyte Membrane Fuel Cells

    PubMed Central

    Jeon, Yukwon; Kim, Dong Jun; Koh, Jong Kwan; Ji, Yunseong; Kim, Jong Hak; Shul, Yong-Gun

    2015-01-01

    Polymer electrolyte membrane fuel cell is a promising zero-emission power generator for stationary/automotive applications. However, key issues, such as performance and costs, are still remained for an economical commercialization. Here, we fabricated a high-performance membrane electrode assembly (MEA) using an interfacial design based on well-arrayed micro-patterned membranes including circles, squares and hexagons with different sizes, which are produced by a facile elastomeric mold method. The best MEA performance is achieved using patterned Nafion membrane with a circle 2 μm in size, which exhibited a very high power density of 1906 mW/cm2 at 75 °C and Pt loading of 0.4 mg/cm2 with 73% improvement compared to the commercial membrane. The improved performance are attributed to the decreased MEA resistances and increased surface area for higher Pt utilization of over 80%. From these enhanced properties, it is possible to operate at lower Pt loading of 0.2 mg/cm2 with an outstanding performance of 1555 mW/cm2 and even at air/low humidity operations. PMID:26552839

  10. Interface-designed Membranes with Shape-controlled Patterns for High-performance Polymer Electrolyte Membrane Fuel Cells

    NASA Astrophysics Data System (ADS)

    Jeon, Yukwon; Kim, Dong Jun; Koh, Jong Kwan; Ji, Yunseong; Kim, Jong Hak; Shul, Yong-Gun

    2015-11-01

    Polymer electrolyte membrane fuel cell is a promising zero-emission power generator for stationary/automotive applications. However, key issues, such as performance and costs, are still remained for an economical commercialization. Here, we fabricated a high-performance membrane electrode assembly (MEA) using an interfacial design based on well-arrayed micro-patterned membranes including circles, squares and hexagons with different sizes, which are produced by a facile elastomeric mold method. The best MEA performance is achieved using patterned Nafion membrane with a circle 2 μm in size, which exhibited a very high power density of 1906 mW/cm2 at 75 °C and Pt loading of 0.4 mg/cm2 with 73% improvement compared to the commercial membrane. The improved performance are attributed to the decreased MEA resistances and increased surface area for higher Pt utilization of over 80%. From these enhanced properties, it is possible to operate at lower Pt loading of 0.2 mg/cm2 with an outstanding performance of 1555 mW/cm2 and even at air/low humidity operations.

  11. Low-Temperature Soft-Cover Deposition of Uniform Large-Scale Perovskite Films for High-Performance Solar Cells.

    PubMed

    Ye, Fei; Tang, Wentao; Xie, Fengxian; Yin, Maoshu; He, Jinjin; Wang, Yanbo; Chen, Han; Qiang, Yinghuai; Yang, Xudong; Han, Liyuan

    2017-09-01

    Large-scale high-quality perovskite thin films are crucial to produce high-performance perovskite solar cells. However, for perovskite films fabricated by solvent-rich processes, film uniformity can be prevented by convection during thermal evaporation of the solvent. Here, a scalable low-temperature soft-cover deposition (LT-SCD) method is presented, where the thermal convection-induced defects in perovskite films are eliminated through a strategy of surface tension relaxation. Compact, homogeneous, and convection-induced-defects-free perovskite films are obtained on an area of 12 cm(2) , which enables a power conversion efficiency (PCE) of 15.5% on a solar cell with an area of 5 cm(2) . This is the highest efficiency at this large cell area. A PCE of 15.3% is also obtained on a flexible perovskite solar cell deposited on the polyethylene terephthalate substrate owing to the advantage of presented low-temperature processing. Hence, the present LT-SCD technology provides a new non-spin-coating route to the deposition of large-area uniform perovskite films for both rigid and flexible perovskite devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Hollow fibre cell fishing with high performance liquid chromatography for screening bioactive anthraquinones from traditional Chinese medicines.

    PubMed

    Yan, Yunyan; Hao, Yaomei; Hu, Shuang; Chen, Xuan; Bai, Xiaohong

    2013-12-27

    Hollow fibre cell fishing with high performance liquid chromatography (HFCF-HPLC) is a newly developed method used to screen and fish bioactive compounds in traditional Chinese medicines (TCMs). In the study, colorectal cancer cell HCT116 was first seeded in a hollow fibre and used for screening and fishing active compounds from TCMs. The surface properties of the hollow fibre seeded with HCT116 cells, the non-specific binding between active centres in the fibre and the target compounds, the cell survival rate under different conditions before and after screening, the repeatability and recovery of HFCF-HPLC were investigated in detail. The cell fishing factor of active compound was defined in HFCF-HPLC. We employed HFCF-HPLC to screen and fish anthraquinones active compounds group from extracts of Polygonum cuspidatum, Cecropia obtusifolia L. and Polygoni multiflori radix praeparata. Some of the anthraquinones structures screened from TCMs were identified by comparing to the retention time of the reference substances confirmed by mass spectrometry. The ability of permeable membrane of anthraquinones screened by HFCF-HPLC was further described. Indomethacin was used as the positive control substance. Results demonstrated that HFCF-HPLC is an effective, stable and reliable method to screen and analyse bioactive compounds. Other bioactive compounds from TCMs could also be screened. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. High-temperature "spectrochronopotentiometry": correlating electrochemical performance with in situ Raman spectroscopy in solid oxide fuel cells.

    PubMed

    Kirtley, John D; Halat, David M; McIntyre, Melissa D; Eigenbrodt, Bryan C; Walker, Robert A

    2012-11-20

    Carbon formation or "coking" on solid oxide fuel cell (SOFC) anodes adversely affects performance by blocking catalytic sites and reducing electrochemical activity. Quantifying these effects, however, often requires correlating changes in SOFC electrochemical efficiency measured during operation with results from ex situ measurements performed after the SOFC has been cooled and disassembled. Experiments presented in this work couple vibrational Raman spectroscopy with chronopotentiometry to observe directly the relationship between graphite deposited on nickel cermet anodes and the electrochemical performance of SOFCs operating at 725 °C. Raman spectra from Ni cermet anodes at open circuit voltage exposed to methane show a strong vibrational band at 1556 cm(-1) assigned to the "G" mode of highly ordered graphite. When polarized in the absence of a gas-phase fuel, these carbon-loaded anodes operate stably, oxidizing graphite to form CO and CO(2). Disappearance of graphite intensity measured in the Raman spectra is accompanied by a steep ∼0.8 V rise in the cell potential needed to keep the SOFC operating under constant current conditions. Continued operation leads to spectroscopically observable Ni oxidation and another steep rise in cell potential. Time-dependent spectroscopic and electrochemical measurements pass through correlated equivalence points providing unequivocal, in situ evidence that identifies how SOFC performance depends on the chemical condition of its anode. Chronopotentiometric data are used to quantify the oxide flux necessary to eliminate the carbon initially present on the SOFC anode, and data show that the oxidation mechanisms responsible for graphite removal correlate directly with the electrochemical condition of the anode as evidenced by voltammetry and impedance measurements. Electrochemically oxidizing the Ni anode damages the SOFC significantly and irreversibly. Anodes that have been reconstituted following electrochemical oxidation of

  14. Room-temperature, solution-processable organic electron extraction layer for high-performance planar heterojunction perovskite solar cells

    SciTech Connect

    Kim, Jong H.; Chueh, Chu-Chen; Williams, Spencer T.; Jen, Alex K. -Y.

    2015-09-24

    Here in this work, we describe a room-temperature, solution-processable organic electron extraction layer (EEL) for high-performance planar heterojunction perovskite solar cells (PHJ PVSCs). This EEL is composed of a bilayered fulleropyrrolidinium iodide (FPI)-polyethyleneimine (PEIE) and PC61BM, which yields a promising power conversion efficiency (PCE) of 15.7% with insignificant hysteresis. We reveal that PC61BM can serve as a surface modifier of FPI-PEIE to simultaneously facilitate the crystallization of perovskite and the charge extraction at FPI-PEIE/CH3NH3PbI3 interface. Furthermore, the FPI-PEIE can also tune the work function of ITO and dope PC61BM to promote the efficient electron transport between ITO and PC61BM. Based on the advantages of room-temperature processability and decent electrical property of FPI-PEIE/PC61BM EEL, a high-performance flexible PVSC with a PCE ~10% is eventually demonstrated. Lastly, this study shows the potential of low-temperature processed organic EEL to replace transition metal oxide-based interlayers for highly printing compatible PVSCs with high-performance.

  15. Room-temperature, solution-processable organic electron extraction layer for high-performance planar heterojunction perovskite solar cells

    DOE PAGES

    Kim, Jong H.; Chueh, Chu-Chen; Williams, Spencer T.; ...

    2015-09-24

    Here in this work, we describe a room-temperature, solution-processable organic electron extraction layer (EEL) for high-performance planar heterojunction perovskite solar cells (PHJ PVSCs). This EEL is composed of a bilayered fulleropyrrolidinium iodide (FPI)-polyethyleneimine (PEIE) and PC61BM, which yields a promising power conversion efficiency (PCE) of 15.7% with insignificant hysteresis. We reveal that PC61BM can serve as a surface modifier of FPI-PEIE to simultaneously facilitate the crystallization of perovskite and the charge extraction at FPI-PEIE/CH3NH3PbI3 interface. Furthermore, the FPI-PEIE can also tune the work function of ITO and dope PC61BM to promote the efficient electron transport between ITO and PC61BM. Basedmore » on the advantages of room-temperature processability and decent electrical property of FPI-PEIE/PC61BM EEL, a high-performance flexible PVSC with a PCE ~10% is eventually demonstrated. Lastly, this study shows the potential of low-temperature processed organic EEL to replace transition metal oxide-based interlayers for highly printing compatible PVSCs with high-performance.« less

  16. Room-temperature, solution-processable organic electron extraction layer for high-performance planar heterojunction perovskite solar cells.

    PubMed

    Kim, Jong H; Chueh, Chu-Chen; Williams, Spencer T; Jen, Alex K-Y

    2015-11-07

    In this work, we describe a room-temperature, solution-processable organic electron extraction layer (EEL) for high-performance planar heterojunction perovskite solar cells (PHJ PVSCs). This EEL is composed of a bilayered fulleropyrrolidinium iodide (FPI)-polyethyleneimine (PEIE) and PC61BM, which yields a promising power conversion efficiency (PCE) of 15.7% with insignificant hysteresis. We reveal that PC61BM can serve as a surface modifier of FPI-PEIE to simultaneously facilitate the crystallization of perovskite and the charge extraction at FPI-PEIE/CH3NH3PbI3 interface. Furthermore, the FPI-PEIE can also tune the work function of ITO and dope PC61BM to promote the efficient electron transport between ITO and PC61BM. Based on the advantages of room-temperature processability and decent electrical property of FPI-PEIE/PC61BM EEL, a high-performance flexible PVSC with a PCE ∼10% is eventually demonstrated. This study shows the potential of low-temperature processed organic EEL to replace transition metal oxide-based interlayers for highly printing compatible PVSCs with high-performance.

  17. High performance polymeric foams

    SciTech Connect

    Gargiulo, M.; Sorrentino, L.; Iannace, S.

    2008-08-28

    The aim of this work was to investigate the foamability of high-performance polymers (polyethersulfone, polyphenylsulfone, polyetherimide and polyethylenenaphtalate). Two different methods have been used to prepare the foam samples: high temperature expansion and two-stage batch process. The effects of processing parameters (saturation time and pressure, foaming temperature) on the densities and microcellular structures of these foams were analyzed by using scanning electron microscopy.

  18. High performance methanol-oxygen fuel cell with hollow fiber electrode

    NASA Technical Reports Server (NTRS)

    Lawson, Daniel D. (Inventor); Ingham, John D. (Inventor)

    1983-01-01

    A methanol/air-oxygen fuel cell including an electrode formed by open-ended ion-exchange hollow fibers having a layer of catalyst deposited on the inner surface thereof and a first current collector in contact with the catalyst layer. A second current collector external of said fibers is provided which is immersed along with the hollow fiber electrode in an aqueous electrolyte body. Upon passage of air or oxygen through the hollow fiber electrode and introduction of methanol into the aqueous electrolyte, a steady current output is obtained. Two embodiments of the fuel cell are disclosed. In the first embodiment the second metal electrode is displaced away from the hollow fiber in the electrolyte body while in the second embodiment a spiral-wrap electrode is provided about the outer surface of the hollow fiber electrode.

  19. High performance and eco-friendly chitosan hydrogel membrane electrolytes for direct borohydride fuel cells

    NASA Astrophysics Data System (ADS)

    Choudhury, Nurul A.; Ma, Jia; Sahai, Yogeshwar

    2012-07-01

    Novel, cost-effective, and environmentally benign polymer electrolyte membranes (PEMs) consisting of ionically cross-linked chitosan (CS) hydrogel is reported for direct borohydride fuel cells (DBFCs). The membranes have been prepared by ionic cross-linking of CS with sulfate and hydrogen phosphate salts of sodium. Use of Na2SO4 and Na2HPO4 as cross-linking agents in the preparation of ionically cross-linked CS hydrogel membrane electrolytes (ICCSHMEs) not only enhances cost-effectiveness but also environmental friendliness of fuel cell technologies. The DBFCs have been assembled with a composite of nickel and carbon-supported palladium as anode catalyst, carbon-supported platinum as cathode catalyst and ICCSHMEs as electrolytes-cum-separators. The DBFCs have been studied by using an aqueous alkaline solution of sodium borohydride as fuel in flowing mode using a peristaltic pump and oxygen as oxidant. A maximum peak power density of about 810 mW cm-2 has been achieved for the DBFC employing Na2HPO4-based ICCSHME and operating at a cell temperature of 70 °C.

  20. Performance comparison of long and short-side chain perfluorosulfonic membranes for high temperature polymer electrolyte membrane fuel cell operation

    NASA Astrophysics Data System (ADS)

    Stassi, A.; Gatto, I.; Passalacqua, E.; Antonucci, V.; Arico, A. S.; Merlo, L.; Oldani, C.; Pagano, E.

    A new Aquivion™ E79-03S short-side chain perfluorosulfonic membrane with a thickness of 30 μm (dry form) and an equivalent weight (EW) of 790 g/equiv recently developed by Solvay-Solexis for high-temperature operation was tested in a pressurised (3 bar abs.) polymer electrolyte membrane (PEM) single cell at a temperature of 130 °C. For comparison, a standard Nafion™ membrane (EW 1100 g/equiv) of similar thickness (50 μm) was investigated under similar operating conditions. Both membranes were tested for high temperature operation in conjunction with an in-house prepared carbon supported Pt electrocatalyst. The electrocatalyst consisted of nanosized Pt particles (particle size ∼2 nm) dispersed on a high surface area carbon black. The electrochemical tests showed better performance for the Aquivion™ membrane as compared to Nafion™ with promising properties for high temperature PEM fuel cell applications. Beside the higher open circuit voltage and lower ohmic constraints, a higher electrocatalytic activity was observed at high temperature for the electrocatalyst-Aquivion™ ionomer interface indicating a better catalyst utilization.

  1. Mesoporous titania-vertical nanorod films with interfacial engineering for high performance dye-sensitized solar cells.

    PubMed

    Ahmed, Irfan; Fakharuddin, Azhar; Wali, Qamar; Bin Zainun, Ayib Rosdi; Ismail, Jamil; Jose, Rajan

    2015-03-13

    Working electrode (WE) fabrication offers significant challenges in terms of achieving high-efficiency dye-sensitized solar cells (DSCs). We have combined the beneficial effects of vertical nanorods grown on conducting glass substrate for charge transport and mesoporous particles for dye loading and have achieved a high photoconversion efficiency of (η) > 11% with an internal quantum efficiency of ∼93% in electrode films of thickness ∼7 ± 0.5 μm. Controlling the interface between the vertical nanorods and the mesoporous film is a crucial step in attaining high η. We identify three parameters, viz., large surface area of nanoparticles, increased light scattering of the nanorod-nanoparticle layer, and superior charge transport of nanorods, that simultaneously contribute to the improved photovoltaic performance of the WE developed.

  2. High-Performance Happy

    ERIC Educational Resources Information Center

    O'Hanlon, Charlene

    2007-01-01

    Traditionally, the high-performance computing (HPC) systems used to conduct research at universities have amounted to silos of technology scattered across the campus and falling under the purview of the researchers themselves. This article reports that a growing number of universities are now taking over the management of those systems and…

  3. High-Performance Happy

    ERIC Educational Resources Information Center

    O'Hanlon, Charlene

    2007-01-01

    Traditionally, the high-performance computing (HPC) systems used to conduct research at universities have amounted to silos of technology scattered across the campus and falling under the purview of the researchers themselves. This article reports that a growing number of universities are now taking over the management of those systems and…

  4. High performance parallel architectures

    SciTech Connect

    Anderson, R.E. )

    1989-09-01

    In this paper the author describes current high performance parallel computer architectures. A taxonomy is presented to show computer architecture from the user programmer's point-of-view. The effects of the taxonomy upon the programming model are described. Some current architectures are described with respect to the taxonomy. Finally, some predictions about future systems are presented. 5 refs., 1 fig.

  5. Low cost and high performance Al nanoparticles for broadband light trapping in Si wafer solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Yinan; Ouyang, Zi; Stokes, Nicholas; Jia, Baohua; Shi, Zhengrong; Gu, Min

    2012-04-01

    In this paper low cost and earth abundant Al nanoparticles are simulated and compared with noble metal nanoparticles Ag and Au for plasmonic light trapping in Si wafer solar cells. It has been found tailored Al nanoparticles enable broadband light trapping leading to a 28.7% photon absorption enhancement in Si wafers, which is much larger than that induced by Ag or Au. Once combined with the SiNx anti-reflection coating, Al nanoparticles can produce a 42.5% enhancement, which is 4.3% higher than the standard SiNx due to the increased absorption in both the blue and near-infrared regions.

  6. Improvement in Direct Methanol Fuel Cell Performance by Treating the Anode at High Anodic Potential

    DTIC Science & Technology

    2014-01-01

    method. Despite causing a slight decrease in the electrochemical surface area (ECSA) of the anode, associated with ruthenium dissolution, AT results...in the electrochemical surface area (ECSA) of the anode, associated with ruthenium dissolution, AT results in signi?cant improvement in DMFC...electrochemical surface area (ECSA) of the anode, associated with ruthenium dissolution, AT results in significant improvement in DMFC performance in the

  7. High Performance, Dependable Multiprocessor

    NASA Technical Reports Server (NTRS)

    Ramos, Jeremy; Samson, John R.; Troxel, Ian; Subramaniyan, Rajagopal; Jacobs, Adam; Greco, James; Cieslewski, Grzegorz; Curreri, John; Fischer, Michael; Grobelny, Eric; George, Alan; Aggarwal, Vikas; Patel, Minesh; Some, Raphael

    2006-01-01

    With the ever increasing demand for higher bandwidth and processing capacity of today's space exploration, space science, and defense missions, the ability to efficiently apply commercial-off-the-shelf (COTS) processors for on-board computing is now a critical need. In response to this need, NASA's New Millennium Program office has commissioned the development of Dependable Multiprocessor (DM) technology for use in payload and robotic missions. The Dependable Multiprocessor technology is a COTS-based, power efficient, high performance, highly dependable, fault tolerant cluster computer. To date, Honeywell has successfully demonstrated a TRL4 prototype of the Dependable Multiprocessor [I], and is now working on the development of a TRLS prototype. For the present effort Honeywell has teamed up with the University of Florida's High-performance Computing and Simulation (HCS) Lab, and together the team has demonstrated major elements of the Dependable Multiprocessor TRLS system.

  8. Enhanced carrier collection efficiency in hierarchical nano-electrode for a high-performance photoelectrochemical cell

    NASA Astrophysics Data System (ADS)

    Hien, Truong Thi; Van Lam, Do; Kim, Chunjoong; Vuong, Nguyen Minh; Quang, Nguyen Duc; Kim, Dahye; Chinh, Nguyen Duc; Hieu, Nguyen Minh; Lee, Seung-Mo; Kim, Dojin

    2016-12-01

    The photoelectrochemical properties of CdS-sensitized ZnO nanorods grown on Pt-coated WO3 nanoplates are investigated to evaluate their effectiveness in hydrogen production. WO3 nanonanoplates are synthesized on glass substrates, followed by atomic layer deposition of Pt thin films as the terminal electrode to efficiently collect the photo-carriers generated from the ZnO/CdS absorption layers. Optimization of the fabrication process for the 3D hierarchical structure is performed, and the morphology and its effect on the photoelectrochemical performance of the electrodes are carefully studied using scanning electron microscopy, x-ray diffraction, and measurements of the photocurrent density and photo-conversion efficiencies. The enhanced PEC performance is elucidated by the 3D hierarchical geometry of the electrode. The optimized electrode shows a photocurrent density of ∼ 13 mA cm-2 and a conversion efficiency of ∼8.0% at -0.83 V (vs. SCE) in 0.5 M Na2S solution under the illumination of simulated solar light.

  9. Industrial-grade rare-earth and perovskite oxide for high-performance electrolyte layer-free fuel cell

    NASA Astrophysics Data System (ADS)

    Xia, Chen; Wang, Baoyuan; Ma, Ying; Cai, Yixiao; Afzal, Muhammad; Liu, Yanyan; He, Yunjuan; Zhang, Wei; Dong, Wenjing; Li, Junjiao; Zhu, Bin

    2016-03-01

    In the present work, we report a composite of industrial-grade material LaCePr-oxide (LCP) and perovskite La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) for advanced electrolyte layer-free fuel cells (EFFCs). The microstructure, morphology, and electrical properties of the LCP, LSCF, and LCP-LSCF composite were investigated and characterized by XRD, SEM, EDS, TEM, and EIS. Various ratios of LCP to LSCF in the composite were modulated to achieve balanced ionic and electronic conductivities. Fuel cell with an optimum ratio of 60 wt% LCP to 40 wt% LSCF reached the highest open circuit voltage (OCV) at 1.01 V and a maximum power density of 745 mW cm-2 at 575 °C, also displaying a good performance stability. The high performance is attributed to the interfacial mechanisms and electrode catalytic effects. The findings from the present study promote industrial-grade rare-earth oxide as a promising new material for innovative low temperature solid oxide fuel cell (LTSOFC) technology.

  10. High performance air electrode for solid oxide regenerative fuel cells fabricated by infiltration of nano-catalysts

    NASA Astrophysics Data System (ADS)

    Lee, Sung-il; Kim, Jeonghee; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook; Je, Hae-June; Lee, Hae-Weon; Song, Huesup; Yoon, Kyung Joong

    2014-03-01

    A high performance air electrode fabricated by infiltration of highly active nano-catalysts into a porous scaffold is demonstrated for high-temperature solid oxide regenerative fuel cells (SORFCs). The nitrate precursor solution for Sm0.5Sr0.5CoO3 (SSC) catalyst is impregnated into a porous La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)-gadolinia-doped ceria (GDC) composite backbone, and extremely fine SSC nano-particles are uniformly synthesized by in-situ crystallization at the initial stage of SORFC operation via homogeneous nucleation induced by urea decomposition. The SSC nano-catalysts are in the size range of 40-80 nm and stable against coarsening upon the SORFC operation at 750 °C. The electrochemical performance is significantly improved by incorporation of SSC nano-catalysts in both power generation and hydrogen production modes. Systematic analysis on the impedance spectra reveals that the surface modification of the air electrode with nano-catalysts remarkably accelerates the chemical surface exchange reactions for both O2 reduction and O2- oxidation, which are the major limiting processes for SORFC performance.

  11. Solvothermal derived crystalline NiOx nanoparticles for high performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Yin, Xingtian; Liu, Jie; Ma, Jiaqi; Zhang, Chongxin; Chen, Peng; Que, Meidan; Yang, Yawei; Que, Wenxiu; Niu, Chunming; Shao, Jinyou

    2016-10-01

    A solvothermal method is employed to synthesize NiOx nanoparticles with good dispersibility. The synthesized NiOx nanoparticles are very homogenous with an average size of about 3-5 nm, and the X-ray diffraction suggests a good crystallinity for the nanoparticles. NiOx films are spin coated from a colloid precursor which is prepared by dispersing the NiOx nanoparticles into ethanol using a certain amount of acetic as the stabilizer. To obtain an efficient hole extraction layer, an annealing process at 300 °C degree is necessary to remove the residual acetic in the NiOx film. Finally, hysteresis-less NiOx-based perovskite solar cells with good reproducibility are achieved, and a highest power conversion efficiency (PCE) of 16.68% and a constant steady state PCE of 16.49% are also demonstrated.

  12. Enhance the optical absorptivity of nanocrystalline TiO2 film with high molar extinction coefficient ruthenium sensitizers for high performance dye-sensitized solar cells.

    PubMed

    Gao, Feifei; Wang, Yuan; Shi, Dong; Zhang, Jing; Wang, Mingkui; Jing, Xiaoyan; Humphry-Baker, Robin; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael

    2008-08-13

    We report two new heteroleptic polypyridyl ruthenium complexes, coded C101 and C102, with high molar extinction coefficients by extending the pi-conjugation of spectator ligands, with a motivation to enhance the optical absorptivity of mesoporous titania film and charge collection yield in a dye-sensitized solar cell. On the basis of this C101 sensitizer, several DSC benchmarks measured under the air mass 1.5 global sunlight have been reached. Along with an acetonitrile-based electrolyte, the C101 sensitizer has already achieved a strikingly high efficiency of 11.0-11.3%, even under a preliminary testing. More importantly, based on a low volatility 3-methoxypropionitrile electrolyte and a solvent-free ionic liquid electrolyte, cells have corresponding >9.0% and approximately 7.4% efficiencies retained over 95% of their initial performances after 1000 h full sunlight soaking at 60 degrees C. With the aid of electrical impedance measurements, we further disclose that, compared to the cell with an acetonitrile-based electrolyte, a dye-sensitized solar cell with an ionic liquid electrolyte shows a feature of much shorter effective electron diffusion lengths due to the lower electron diffusion coefficients and shorter electron lifetimes in the mesoporous titania film, explaining the photocurrent difference between these two type devices. This highlights the next necessary efforts to further improve the efficiency of cells with ionic liquid electrolytes, facilitating the large-scale production and application of flexible thin film mesoscopic solar cells.

  13. C18 ceramide analysis in mammalian cells employing reversed-phase high-performance liquid chromatography tandem mass spectrometry.

    PubMed

    Haynes, Teka-Ann S; Duerksen-Hughes, Penelope J; Filippova, Maria; Filippov, Valery; Zhang, Kangling

    2008-07-01

    Ceramides play an important role in diverse cellular functions such as differentiation, cell cycle progression, cell-cell adhesion, senescence, and apoptosis. Here we report a method of extracting lipids from mammalian cells and quantifying ceramide, where the assay conditions were optimized for reproducibility, linearity, recovery, and sensitivity. Simultaneous chromatographic separations were carried out by reversed-phase high-performance liquid chromatography coupled to electrospray ionization using a Pursuit 3 Diphenyl column (50 x 2.0 mm) and supported by a mobile phase consisting of acetonitrile plus 0.1% formic acid and 25 mM ammonium acetate. Ceramides were detected in the multiple reaction mode by tandem mass spectrometry in the positive ion mode, and all extracted ion peaks were integrated for quantitative analysis. The limits of detection and quantification achieved were 0.2 and 1.0 pg on column, respectively. Using this method, we successfully quantified and compared differences in C(18) ceramide levels induced by two DNA-damaging agents, mitomycin C and daunorubicin, and two apoptosis-inducing ligands, tumor necrosis factor alpha (TNF-alpha) and TNF-related apoptosis-inducing ligand (TRAIL). This work, therefore, describes a method that will be helpful for investigating how ceramide is regulated by different chemotherapeutic agents and will help us to better understand the mechanisms of signal transduction involving ceramide.

  14. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-12-31

    DOE has launched a program to make a step change in power plant to 1500 F steam, since the highest possible performance gains can be achieved in a 1500 F steam system when using a topping turbine in a back pressure steam turbine for cogeneration. A 500-hour proof-of-concept steam generator test module was designed, fabricated, and successfully tested. It has four once-through steam generator circuits. The complete HPSS (high performance steam system) was tested above 1500 F and 1500 psig for over 102 hours at full power.

  15. High-performance CH3NH3PbI3 perovskite solar cells fabricated under ambient conditions with high relative humidity

    NASA Astrophysics Data System (ADS)

    Lei, Binglong; Obiozo Eze, Vincent; Mori, Tatsuo

    2015-10-01

    Hygroscopic perovskite solar cells are commonly fabricated under conditions of inert atmosphere or low relative humidity (RH). To generate high-performance perovskite light-absorbing layers for super power conversion efficiency (PCE), we fabricated CH3NH3PbI3 solar cells under ambient conditions (RH = 42-48%) by a flowing gas directly from high-RH air. The primary advantage of this technique, together with the casting of a hot solution and quick conduction, enabled us to achieve the highest and average PCEs of 16.32 and 14.27% respectively, with an extremely small deviation of 0.49%. Our research will be of significance for fabricating highly efficient and reproducible perovskite photovoltaics.

  16. A New Strategy to Construct Low Bandgap Polymer Acceptor for High Performance All-Polymer Solar Cells.

    PubMed

    Li, Yongfang; Zhang, Zhi-Guo; Yang, Yankang; Yao, Jia; Xue, Lingwei; Chen, Shanshan; Li, Xiaojun; Morrison, William; Yang, Changduk

    2017-08-29

    All polymer solar cells (all-PSCs) offer unique morphology stability for the application as flexible devices, but the lack of high performance polymer acceptors limits their power conversion efficiency (PCE) lower than the PSCs based on fullerene derivative or organic small molecule acceptors. We herein demonstrate a strategy to synthesize a high performance polymer acceptor PZ1 by embedding an acceptor-donor-acceptor building block into the polymer main chain. PZ1 possesses broad absorption with a low bandgap of 1.55 eV and high absorption coefficient (1.3 × 105 cm-1). The all-PSCs with a wide bandgap polymer PBDT-T as donor and PT1 as acceptor demonstrated a record high PCE of 9.19% for the all-PSCs. The success of our polymerization strategy can provide a new way to develop efficient polymer acceptors for all-PSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Pt-Bi decorated nanoporous gold for high performance direct glucose fuel cell

    PubMed Central

    Guo, Hong; Yin, Huiming; Yan, Xiuling; Shi, Shuai; Yu, Qingyang; Cao, Zhen; Li, Jian

    2016-01-01

    Binary PtBi decorated nanoporous gold (NPG-PtBi) electrocatalyst is specially designed and prepared for the anode in direct glucose fuel cells (DGFCs). By using electroless and electrochemical plating methods, a dense Pt layer and scattered Bi particles are sequentially coated on NPG. A simple DGFC with NPG-PtBi as anode and commercial Pt/C as cathode is constructed and operated to study the effect of operating temperatures and concentrations of glucose and NaOH. With an anode noble metal loading of only 0.45 mg cm−2 (Au 0.3 mg and Pt 0.15 mg), an open circuit voltage (OCV) of 0.9 V is obtained with a maximum power density of 8 mW cm−2. Furthermore, the maximum gravimetric power density of NPG-PtBi is 18 mW mg−1, about 4.5 times higher than that of commercial Pt/C. PMID:27966629

  18. Pt-Bi decorated nanoporous gold for high performance direct glucose fuel cell.

    PubMed

    Guo, Hong; Yin, Huiming; Yan, Xiuling; Shi, Shuai; Yu, Qingyang; Cao, Zhen; Li, Jian

    2016-12-14

    Binary PtBi decorated nanoporous gold (NPG-PtBi) electrocatalyst is specially designed and prepared for the anode in direct glucose fuel cells (DGFCs). By using electroless and electrochemical plating methods, a dense Pt layer and scattered Bi particles are sequentially coated on NPG. A simple DGFC with NPG-PtBi as anode and commercial Pt/C as cathode is constructed and operated to study the effect of operating temperatures and concentrations of glucose and NaOH. With an anode noble metal loading of only 0.45 mg cm(-2) (Au 0.3 mg and Pt 0.15 mg), an open circuit voltage (OCV) of 0.9 V is obtained with a maximum power density of 8 mW cm(-2). Furthermore, the maximum gravimetric power density of NPG-PtBi is 18 mW mg(-1), about 4.5 times higher than that of commercial Pt/C.

  19. Pt-Bi decorated nanoporous gold for high performance direct glucose fuel cell

    NASA Astrophysics Data System (ADS)

    Guo, Hong; Yin, Huiming; Yan, Xiuling; Shi, Shuai; Yu, Qingyang; Cao, Zhen; Li, Jian

    2016-12-01

    Binary PtBi decorated nanoporous gold (NPG-PtBi) electrocatalyst is specially designed and prepared for the anode in direct glucose fuel cells (DGFCs). By using electroless and electrochemical plating methods, a dense Pt layer and scattered Bi particles are sequentially coated on NPG. A simple DGFC with NPG-PtBi as anode and commercial Pt/C as cathode is constructed and operated to study the effect of operating temperatures and concentrations of glucose and NaOH. With an anode noble metal loading of only 0.45 mg cm-2 (Au 0.3 mg and Pt 0.15 mg), an open circuit voltage (OCV) of 0.9 V is obtained with a maximum power density of 8 mW cm-2. Furthermore, the maximum gravimetric power density of NPG-PtBi is 18 mW mg-1, about 4.5 times higher than that of commercial Pt/C.

  20. High-Performance Porphyrin-Based Dye-Sensitized Solar Cells with Iodine and Cobalt Redox Shuttles.

    PubMed

    Xiang, Huaide; Fan, Wei; Li, Jia Hui; Li, Tianyue; Robertson, Neil; Song, Xiongrong; Wu, Wenjun; Wang, Zhaohui; Zhu, Weihong; Tian, He

    2017-03-09

    Recently, enormous research passion has been devoted to enhance the power conversion efficiency (PCE) of porphyrin sensitizers for dye-sensitized solar cells (DSSCs), but the major stumbling block is the absorption defect in the visible-light region. To address this challenge, high-performance DSSCs are reported based on a new donor-π-acceptor sensitizer FW-1, 7H-dibenzo[c,g]carbazole-substituted and fused zinc porphyrin, co-sensitized with a benzotriazole-containing dye (WS-5) in iodine and cobalt redox systems, and high PCEs of 10.21 and 10.42 %, respectively, were obtained. An unprecedented breakthrough was obtained by making one sensitizer suitable for several electrolyte systems because of its appropriate molecular orbitals and co-sensitizer. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Pinning down high-performance Cu-chalcogenides as thin-film solar cell absorbers: A successive screening approach.

    PubMed

    Zhang, Yubo; Wang, Youwei; Zhang, Jiawei; Xi, Lili; Zhang, Peihong; Zhang, Wenqing

    2016-05-21

    Photovoltaic performances of Cu-chalcogenides solar cells are strongly correlated with the absorber fundamental properties such as optimal bandgap, desired band alignment with window material, and high photon absorption ability. According to these criteria, we carry out a successive screening for 90 Cu-chalcogenides using efficient theoretical approaches. Besides the well-recognized CuInSe2 and Cu2ZnSnSe4 materials, several novel candidates are identified to have optimal bandgaps of around 1.0-1.5 eV, spike-like band alignments with CdS window layer, sharp photon absorption edges, and high absorption coefficients. These new systems have great potential to be superior absorbers for photovolatic applications if their carrrier transport and defect properties are properly optimized.

  2. Sub-100 °C solution processed amorphous titania nanowire thin films for high-performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Wu-Qiang; Chen, Dehong; Huang, Fuzhi; Cheng, Yi-Bing; Caruso, Rachel A.

    2016-10-01

    The present work demonstrates a facile one-step process to fabricate thin films of amorphous titania nanowires on transparent conducting oxide substrates via hydrolysis of potassium titanium oxide oxalate in an aqueous solution at 90 °C. The resultant titania nanowire thin films (that have not undergone further annealing) are efficient electron transport layers in CH3NH3PbI3 perovskite solar cells, yielding full sun solar-to-electricity conversion efficiencies of up to 14.67% and a stabilized efficiency of 14.00% under AM 1.5G one sun illumination, comparable to high temperature sintered TiO2 counterparts. The high photovoltaic performance is attributed to the porous nanowire network that facilitates perovskite infiltration, its unique 1D geometry and excellent surface coverage for efficient electron transport, as well as suppressed charge recombination between FTO and perovskite.

  3. High efficiency solar cell processing

    NASA Technical Reports Server (NTRS)

    Ho, F.; Iles, P. A.

    1985-01-01

    At the time of writing, cells made by several groups are approaching 19% efficiency. General aspects of the processing required for such cells are discussed. Most processing used for high efficiency cells is derived from space-cell or concentrator cell technology, and recent advances have been obtained from improved techniques rather than from better understanding of the limiting mechanisms. Theory and modeling are fairly well developed, and adequate to guide further asymptotic increases in performance of near conventional cells. There are several competitive cell designs with promise of higher performance ( 20%) but for these designs further improvements are required. The available cell processing technology to fabricate high efficiency cells is examined.

  4. Highly flexible InSnO electrodes on thin colourless polyimide substrate for high-performance flexible CH3NH3PbI3 perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Il; Heo, Jin Hyuck; Park, Sung-Hyun; Hong, Ki Il; Jeong, Hak Gee; Im, Sang Hyuk; Kim, Han-Ki

    2017-02-01

    We fabricated high-performance flexible CH3NH3PbI3 (MAPbI3) perovskite solar cells with a power conversion efficiency of 15.5% on roll-to-roll sputtered ITO films on 60 μm-thick colourless polyimide (CPI) substrate. Due to the thermal stability of the CPI substrate, an ITO/CPI sample subjected to rapid thermal annealing at 300 °C showed a low sheet resistance of 57.8 Ω/square and high transmittance of 83.6%, which are better values than those of an ITO/PET sample. Outer and inner bending tests demonstrated that the mechanical flexibility of the ITO/CPI was superior to that of the conventional ITO/PET sample owing to the thinness of the CPI substrate. In addition, due to its good mechanical flexibility, the ITO/CPI showed no change in resistance after 10,000 cycle outer and inner dynamic fatigue tests. Flexible perovskite solar cells with the structure of Au/PTAA/MAPbI3/ZnO/ITO/CPI showed a high power conversion efficiency of 15.5%. The successful operation of these flexible perovskite solar cells on ITO/CPI substrate indicated that the ITO film on thermally stable CPI substrate is a promising of flexible substrate for high-temperature processing, a finding likely to advance the commercialization of cost-efficient flexible perovskite solar cells.

  5. High Performance FORTRAN

    NASA Technical Reports Server (NTRS)

    Mehrotra, Piyush

    1994-01-01

    High performance FORTRAN is a set of extensions for FORTRAN 90 designed to allow specification of data parallel algorithms. The programmer annotates the program with distribution directives to specify the desired layout of data. The underlying programming model provides a global name space and a single thread of control. Explicitly parallel constructs allow the expression of fairly controlled forms of parallelism in particular data parallelism. Thus the code is specified in a high level portable manner with no explicit tasking or communication statements. The goal is to allow architecture specific compilers to generate efficient code for a wide variety of architectures including SIMD, MIMD shared and distributed memory machines.

  6. Numerical study of a flat-tube high power density solid oxide fuel cell. Part II: Cell performance and stack optimization

    NASA Astrophysics Data System (ADS)

    Lu, Yixin; Schaefer, Laura

    The flat-tube high power density (HPD) solid oxide fuel cell (SOFC) is a geometry based on a tubular type SOFC, and is being developed by Siemens Westinghouse and other international companies in Japan and Korea. It has increased power density, but still maintains the beneficial feature of secure sealing for a tubular SOFC. In this paper, the electric performance of a flat-tube HPD SOFC is studied. This paper also investigates the effects of the stack chamber number, stack shape, and other stack geometry features on the performance of the flat-tube HPD SOFC. The results show that the performance of a flat-tube HPD SOFC is better than a tubular SOFC with the same active cell surface, and that increasing the number of chambers number can improve the overall performance of a flat-tube HPD SOFC. The height of a flat-tube HPD SOFC and the thickness of the ribs do not have much effect on the performance of the cell as is expected. This study will help to design and optimize the flat-tube HPD SOFC.

  7. High Performance Window Retrofit

    SciTech Connect

    Shrestha, Som S; Hun, Diana E; Desjarlais, Andre Omer

    2013-12-01

    The US Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and Traco partnered to develop high-performance windows for commercial building that are cost-effective. The main performance requirement for these windows was that they needed to have an R-value of at least 5 ft2 F h/Btu. This project seeks to quantify the potential energy savings from installing these windows in commercial buildings that are at least 20 years old. To this end, we are conducting evaluations at a two-story test facility that is representative of a commercial building from the 1980s, and are gathering measurements on the performance of its windows before and after double-pane, clear-glazed units are upgraded with R5 windows. Additionally, we will use these data to calibrate EnergyPlus models that we will allow us to extrapolate results to other climates. Findings from this project will provide empirical data on the benefits from high-performance windows, which will help promote their adoption in new and existing commercial buildings. This report describes the experimental setup, and includes some of the field and simulation results.

  8. Catalyzed double layer cathodes for high performance and long life molten carbonate fuel cells

    SciTech Connect

    Bischoff, M.; Jantsch, U.; Rohland, B.

    1996-12-31

    NiO/LiCoO{sub 2} double layer cathodes (DLCs) were prepared with a thin highly active LiCoO{sub 2}-layer by a new double layer tape casting/sintering procedure. The resulting metallic porous precursor plates were mounted into the MCFC and heated up by a special procedure to form LiCoO{sub 2} from air, Co and Li{sub 2}CO{sub 3} in a solid/gas reaction. MCFCs with highly active NiO/LiCoO{sub 2}-DLCs can operate over prolonged periods of time with a Ni-precipitation which is 10% lower than one finds with state of the art NiO cathodes. According to LiCoO{sub 2}-cathodes have theoretical life times of more than 100 000 hours at nonpressurized conditions. MCFCs with new NiO/LiCoO{sub 2} double layer cathodes (DLC) were investigated with regard to variable parameters of their microstructure. From the agglomerate model of the porous MCFC cathode, the dependence of the polarization resistance from the radius of the agglomerates and the inner agglomerate surface area was calculated.

  9. High performance monolithic power management system with dynamic maximum power point tracking for microbial fuel cells.

    PubMed

    Erbay, Celal; Carreon-Bautista, Salvador; Sanchez-Sinencio, Edgar; Han, Arum

    2014-12-02

    Microbial fuel cell (MFC) that can directly generate electricity from organic waste or biomass is a promising renewable and clean technology. However, low power and low voltage output of MFCs typically do not allow directly operating most electrical applications, whether it is supplementing electricity to wastewater treatment plants or for powering autonomous wireless sensor networks. Power management systems (PMSs) can overcome this limitation by boosting the MFC output voltage and managing the power for maximum efficiency. We present a monolithic low-power-consuming PMS integrated circuit (IC) chip capable of dynamic maximum power point tracking (MPPT) to maximize the extracted power from MFCs, regardless of the power and voltage fluctuations from MFCs over time. The proposed PMS continuously detects the maximum power point (MPP) of the MFC and matches the load impedance of the PMS for maximum efficiency. The system also operates autonomously by directly drawing power from the MFC itself without any external power. The overall system efficiency, defined as the ratio between input energy from the MFC and output energy stored into the supercapacitor of the PMS, was 30%. As a demonstration, the PMS connected to a 240 mL two-chamber MFC (generating 0.4 V and 512 μW at MPP) successfully powered a wireless temperature sensor that requires a voltage of 2.5 V and consumes power of 85 mW each time it transmit the sensor data, and successfully transmitted a sensor reading every 7.5 min. The PMS also efficiently managed the power output of a lower-power producing MFC, demonstrating that the PMS works efficiently at various MFC power output level.

  10. [Detecting doxorubicin concentration in KBv200 and KB cell xenografts in nude mice by high-performance liquid chromatography].

    PubMed

    Deng, Wen-Jing; Zeng, Zhao-Lei; Liang, Yong-Ju; Dai, Chun-Ling; Zhang, Jian-Ye; Fu, Li-Wu

    2008-04-01

    Doxorubicin (Dox) is one of the most commonly used chemotherapeutic drugs. Drug concentrations in tumor tissue can predict the drugos efficacy better than that in serum do. This study was to detect and compare the concentration of Dox in KBv200 and KB cell xenografts in nude mice by high-performance liquid chromatography (HPLC). Tumor models in nude mice were established with KB cells (drug-sensitive) and KBv200 cells (multidrug-resistant). Dox was injected via the tail vein. The concentration of Dox in tumor tissue was detected by HPLC at 1, 3 and 5 h after injection. A Hypersil reversed-phase BDS C18 column (250 mm x 4.6 mm, ID 5 microm) and mobile phases that were composed of acetonitrile and 0.02 mol/L KH2PO4 (1/2.4, V/V, pH 3.9) at a flow rate of 1.0 mL/min were used for setting a fluorescence detector (excitation wave length was 480 nm; emission wave length was 580 nm). Under the condition of HPLC, the calibration curve of Dox concentration in tumor tissue was linear within a range of 29.3-7 500 ng/g (r=0.9998). The limit of detection in tumor tissue was 14 ng/g. At the concentration of 3 750, 468.8 and 117.2 ng/g, extraction recovery were (99.35+/-7.65)%, (99.79+/-5.73)% and (103.67+/-6.76)%, respectively, method recovery were (91.89+/-7.03)%, (94.94+/-5.18)% and (100.83+/-5.32)%, respectively. The relative standard deviation (RSD) of the intra-day and inter-day precision were less than 4.2%. At 1, 3, 5 h after Dox injection, the concentrations of Dox were (139.32+/-54.68), (260.00+/-126.11) and (173.26+/-13.88) ng/g in KBv cell xenografts, respectively, and (385.13+/-42.55), (523.38+/-138.84) and (460.75+/-86.85) ng/g in KB cell xenografts, respectively. The Dox concentration was significantly higher in KB cell xenografts than in KBv200 cell xenografts at the same time point (P<0.05). Detected by HPLC, the concentration of Dox is much lower in multidrug-resistant cell xenografts than in sensitive cell xenografts.

  11. Low temperature synthesis of hierarchical TiO2 nanostructures for high performance perovskite solar cells by pulsed laser deposition.

    PubMed

    Yang, Bin; Mahjouri-Samani, Masoud; Rouleau, Christopher M; Geohegan, David B; Xiao, Kai

    2016-10-21

    A promising way to advance perovskite solar cells is to improve the quality of the electron transport material -e.g., titanium dioxide (TiO2) - in a direction that increases electron transport and extraction. Although dense TiO2 films are easily grown in solution, efficient electron extraction suffers due to a lack of interfacial contact area with the perovskites. Conversely, mesoporous films do offer high surface-area-to-volume ratios, thereby promoting efficient electron extraction, but their morphology is relatively difficult to control via conventional solution synthesis methods. Here, a pulsed laser deposition method was used to assemble TiO2 nanoparticles into TiO2 hierarchical architectures exhibiting an anatase crystal structure, and prototype solar cells employing these structures yielded power conversion efficiencies of ∼14%. Our approach demonstrates a way to grow high aspect-ratio TiO2 nanostructures for improved interfacial contact between TiO2 and perovskite materials, leading to high electron-hole pair separation and electron extraction efficiencies for superior photovoltaic performance. Compared to previous pulsed laser deposition-synthesized TiO2 mesoporous crystalline networks that needed post-thermal annealing at 500 °C to form mesoporous crystalline networks, our relatively low temperature (300 °C) TiO2 processing method may promote reduced energy-consumption during device fabrication, as well as enable compatibility with flexible polymer substrates such as polyimide.

  12. Low temperature synthesis of hierarchical TiO2 nanostructures for high performance perovskite solar cells by pulsed laser deposition

    DOE PAGES

    Yang, Bin; Mahjouri-Samani, Masoud; Rouleau, Christopher M.; ...

    2016-06-10

    A promising way to advance perovskite solar cells is to improve the quality of the electron transport material e.g., titanium dioxide (TiO2) in a direction that increases electron transport and extraction. Although dense TiO2 films are easily grown in solution, efficient electron extraction suffers due to a lack of interfacial contact area with the perovskite. Conversely, mesoporous films do offer high surface-area-to-volume ratios, thereby promoting efficient electron extraction, but their morphology is relatively difficult to control via conventional solution synthesis methods. Here, a pulsed laser deposition method was used to assemble TiO2 nanoparticles into TiO2 hierarchical nanoarchitectures having the anatasemore » crystal structure, and prototype solar cells employing these structures yielded power conversion efficiencies of ~ 14%. Our approach demonstrates a way to grow high aspect-ratio TiO2 nanostructures for improved interfacial contact between TiO2 and perovskite materials, leading to high electron-hole pair separation and electron extraction efficiencies for superior photovoltaic performance. In addition, compared to conventional solution-processed TiO2 films that require 500 °C to obtain a good crystallinity, our relatively low temperature (300 °C) TiO2 processing method may promote reduced energy-consumption during device fabrication as well as enable compatibility with various flexible polymer substrates.« less

  13. Cosensitized Porphyrin System for High-Performance Solar Cells with TOF-SIMS Analysis.

    PubMed

    Wu, Wenjun; Xiang, Huaide; Fan, Wei; Wang, Jinglin; Wang, Haifeng; Hua, Xin; Wang, Zhaohui; Long, Yitao; Tian, He; Zhu, Wei-Hong

    2017-05-17

    To date, development of organic sensitizers has been predominately focused on light harvesting, highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels, and the electron transferring process. In contrast, their adsorption mode as well as the dynamic loading behavior onto nanoporous TiO2 is rarely considered. Herein, we have employed the time-of-flight secondary ion mass spectrometry (TOF-SIMS) to gain insight into the competitive dye adsorption mode and kinetics in the cosensitized porphyrin system. Using novel porphyrin dye FW-1 and D-A-π-A featured dye WS-5, the different bond-breaking mode in TOF-SIMS and dynamic dye-loading amount during the coadsorption process are well-compared with two different anchoring groups, such as benzoic acid and cyanoacrylic acid. With the bombardment mode in TOF-SIMS spectra, we have speculated that the cyano group grafts onto nanoporous TiO2 as tridentate binding for the common anchoring unit of cyanoacrylic acid and confirmed it through extensive first-principles density functional theory calculation by anchoring either the carboxyl or cyano group, which shows that the cyano group can efficiently participate in the adsorption of the WS-5 molecule onto the TiO2 nanocrystal. The grafting reinforcement interaction between the cyano group and TiO2 in WS-5 can well-explain the rapid adsorption characteristics. A strong coordinate bond between the lone pair of electrons on the nitrogen or oxygen atom and the Lewis acid sites of TiO2 can increase electron injection efficiencies with respect to those from the bond between the benzoic acid group and the Brønsted acid sites of the TiO2 surface. Upon optimization of the coadsorption process with dye WS-5, the photoelectric conversion efficiency based on porphyrin dye FW-1 is increased from 6.14 to 9.72%. The study on the adsorption dynamics of organic sensitizers with TOF-SIMS analysis might provide a new venue for improvement of cosensitized solar cells.

  14. n-Type Water/Alcohol-Soluble Naphthalene Diimide-Based Conjugated Polymers for High-Performance Polymer Solar Cells.

    PubMed

    Wu, Zhihong; Sun, Chen; Dong, Sheng; Jiang, Xiao-Fang; Wu, Siping; Wu, Hongbin; Yip, Hin-Lap; Huang, Fei; Cao, Yong

    2016-02-17

    With the demonstration of small-area, single-junction polymer solar cells (PSCs) with power conversion efficiencies (PCEs) over the 10% performance milestone, the manufacturing of high-performance large-area PSC modules is becoming the most critical issue for commercial applications. However, materials and processes that are optimized for fabricating small-area devices may not be applicable for the production of high-performance large-area PSC modules. One of the challenges is to develop new conductive interfacial materials that can be easily processed with a wide range of thicknesses without significantly affecting the performance of the PSCs. Toward this goal, we report two novel naphthalene diimide-based, self-doped, n-type water/alcohol-soluble conjugated polymers (WSCPs) that can be processed with a broad thickness range of 5 to 100 nm as efficient electron transporting layers (ETLs) for high-performance PSCs. Space charge limited current and electron spin resonance spectroscopy studies confirm that the presence of amine or ammonium bromide groups on the side chains of the WSCP can n-dope PC71BM at the bulk heterojunction (BHJ)/ETL interface, which improves the electron extraction properties at the cathode. In addition, both amino functional groups can induce self-doping to the WSCPs, although by different doping mechanisms, which leads to highly conductive ETLs with reduced ohmic loss for electron transport and extraction. Ultimately, PSCs based on the self-doped WSCP ETLs exhibit significantly improved device performance, yielding PCEs as high as 9.7% and 10.11% for PTB7-Th/PC71BM and PffBT4T-2OD/PC71BM systems, respectively. More importantly, with PffBT4T-2OD/PC71BM BHJ as an active layer, a prominent PCE of over 8% was achieved even when a thick ETL of 100 nm was used. To the best of our knowledge, this is the highest efficiency demonstrated for PSCs with a thick interlayer and light-harvesting layer, which are important criteria for eventually making

  15. An organic surface modifier to produce a high work function transparent electrode for high performance polymer solar cells.

    PubMed

    Choi, Hyosung; Kim, Hak-Beom; Ko, Seo-Jin; Kim, Jin Young; Heeger, Alan J

    2015-02-04

    Modification of an ITO electrode with small-molecule organic surface modifier, 4-chloro-benzoic acid (CBA), via a simple spin-coating method produces a high-work-function electrode with high transparency and a hydrophobic surface. As an alternative to PEDOT:PSS, CBA modification achieves efficiency enhancement up to 8.5%, which is attributed to enhanced light absorption within the active layer and smooth hole transport from the active layer to the anode.

  16. High-performance of PEDOT/PSS free organic solar cells on an air-plasma-treated ITO substrate.

    PubMed

    Choi, Jong Kil; Jin, Ming Liang; An, Cheng Jin; Kim, Dae Woo; Jung, Hee-Tae

    2014-07-23

    In this work, we demonstrate the high-performance of a PEDOT:PSS free organic photovoltaic cell (OPVC) using an air-plasma modified ITO surface, followed by controlled solvent evaporation and annealing of the P3HT:PCBM photoactive layer. Ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), and conductive atomic force microscopy (c-AFM) results show that the work function of ITO was increased to as high as that of PEDOT:PSS (5.2 eV) after air-plasma treatment, along with significantly enhanced electrical homogeneity. From the dynamic secondary ion mass spectroscopy (DSIMS) results, we confirm that the thermodynamic stability of the slow-dried active layer is attributed to the uniform vertical compositional distribution on the air plasma treated ITO surface, even after thermal annealing at 150 °C for 10 min. The resulting device has an open-circuit voltage of 0.65 V, a fill factor of 63%, and a power conversion efficiency of 3.38%, providing a high performance PEDOT:PSS free OPVC device.

  17. Improved performance of the microbial electrolysis desalination and chemical-production cell with enlarged anode and high applied voltages.

    PubMed

    Ye, Bo; Luo, Haiping; Lu, Yaobin; Liu, Guangli; Zhang, Renduo; Li, Xiao

    2017-11-01

    The aim of this study was to improve performance of the microbial electrolysis desalination and chemical-production cell (MEDCC) using enlarged anode and high applied voltages. MEDCCs with anode lengths of 9 and 48cm (i.e., the 9cm-anode MEDCC and 48cm-anode MEDCC, respectively) were tested under different voltages (1.2-3.0V). Our results demonstrated for the first time that the MEDCC could maintain high performance even under the applied voltage higher than that for water dissociation (i.e., 1.8V). Under the applied voltage of 2.5V, the maximum current density in the 48cm-anode MEDCC reached 32.8±2.6A/m(2), which is one of the highest current densities reported so far in the bioelectrochemical system (BES). The relative abundance of Geobacter was changed along the anode length. Our results show the great potential of the BES with enlarged anode and high applied voltages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Ground and excited state properties of high performance anthocyanidin dyes-sensitized solar cells in the basic solutions

    SciTech Connect

    Prima, Eka Cahya; Yuliarto, Brian; Suyatman; Dipojono, Hermawan Kresno

    2015-09-30

    The aglycones of anthocyanidin dyes were previously reported to form carbinol pseudobase, cis-chalcone, and trans-chalcone due to the basic levels. The further investigations of ground and excited state properties of the dyes were characterized using density functional theory with PCM(UFF)/B3LYP/6-31+G(d,p) level in the basic solutions. However, to the best of our knowledge, the theoretical investigation of their potential photosensitizers has never been reported before. In this paper, the theoretical photovoltaic properties sensitized by dyes have been successfully investigated including the electron injections, the ground and excited state oxidation potentials, the estimated open circuit voltages, and the light harvesting efficiencies. The results prove that the electronic properties represented by dyes’ LUMO-HOMO levels will affect to the photovoltaic performances. Cis-chalcone dye is the best anthocyanidin aglycone dye with the electron injection spontaneity of −1.208 eV, the theoretical open circuit voltage of 1.781 V, and light harvesting efficiency of 56.55% due to the best HOMO-LUMO levels. Moreover, the ethanol solvent slightly contributes to the better cell performance than the water solvent dye because of the better oxidation potential stabilization in the ground state as well as in the excited state. These results are in good agreement with the known experimental report that the aglycones of anthocyanidin dyes in basic solvent are the high potential photosensitizers for dye-sensitized solar cell.

  19. Ground and excited state properties of high performance anthocyanidin dyes-sensitized solar cells in the basic solutions

    NASA Astrophysics Data System (ADS)

    Prima, Eka Cahya; Yuliarto, Brian; Suyatman, Dipojono, Hermawan Kresno

    2015-09-01

    The aglycones of anthocyanidin dyes were previously reported to form carbinol pseudobase, cis-chalcone, and trans-chalcone due to the basic levels. The further investigations of ground and excited state properties of the dyes were characterized using density functional theory with PCM(UFF)/B3LYP/6-31+G(d,p) level in the basic solutions. However, to the best of our knowledge, the theoretical investigation of their potential photosensitizers has never been reported before. In this paper, the theoretical photovoltaic properties sensitized by dyes have been successfully investigated including the electron injections, the ground and excited state oxidation potentials, the estimated open circuit voltages, and the light harvesting efficiencies. The results prove that the electronic properties represented by dyes' LUMO-HOMO levels will affect to the photovoltaic performances. Cis-chalcone dye is the best anthocyanidin aglycone dye with the electron injection spontaneity of -1.208 eV, the theoretical open circuit voltage of 1.781 V, and light harvesting efficiency of 56.55% due to the best HOMO-LUMO levels. Moreover, the ethanol solvent slightly contributes to the better cell performance than the water solvent dye because of the better oxidation potential stabilization in the ground state as well as in the excited state. These results are in good agreement with the known experimental report that the aglycones of anthocyanidin dyes in basic solvent are the high potential photosensitizers for dye-sensitized solar cell.

  20. Study of Arylamine-Substituted Porphyrins as Hole-Transporting Materials in High-Performance Perovskite Solar Cells.

    PubMed

    Chen, Song; Liu, Peng; Hua, Yong; Li, Yuanyuan; Kloo, Lars; Wang, Xingzhu; Ong, Beng; Wong, Wai-Kwok; Zhu, Xunjin

    2017-04-19

    To develop new hole-transporting materials (HTMs) for efficient and stable perovskite solar cells (PSCs), 5,10,15,20-tetrakis{4-[N,N-di(4-methoxylphenyl)amino-phenyl]}-porphyrin was prepared in gram scale through the direct condensation of pyrrole and 4-[bis(4-methoxyphenyl)amino]benzaldehyde. Its Zn(II) and Cu(II) complexes exhibit excellent thermal and electrochemical stability, specifically a high hole mobility and very favorable energetics for hole extraction that render them a new class of HTMs in organometallic halide PSCs. As expected, ZnP as HTM in PSCs affords a competitive power conversion efficiency (PCE) of 17.78%, which is comparable to that of the most powerful HTM of Spiro-MeOTAD (18.59%) under the same working conditions. Meanwhile, the metal centers affect somewhat the photovoltaic performances that CuP as HTM produces a lower PCE of 15.36%. Notably, the PSCs employing ZnP show a much better stability than Spiro-OMeTAD. Moreover, the two porphyrin-based HTMs can be prepared from relatively cheap raw materials with a facile synthetic route. The results demonstrate that ZnP and CuP can be a new class of HTMs for efficient and stable PSCs. To the best of our knowledge, this is the best performance that porphyrin-based solar cells could show with PCE > 17%.

  1. High Performance Buildings Database

    DOE Data Explorer

    The High Performance Buildings Database is a shared resource for the building industry, a unique central repository of in-depth information and data on high-performance, green building projects across the United States and abroad. The database includes information on the energy use, environmental performance, design process, finances, and other aspects of each project. Members of the design and construction teams are listed, as are sources for additional information. In total, up to twelve screens of detailed information are provided for each project profile. Projects range in size from small single-family homes or tenant fit-outs within buildings to large commercial and institutional buildings and even entire campuses. The database is a data repository as well. A series of Web-based data-entry templates allows anyone to enter information about a building project into the database. Once a project has been submitted, each of the partner organizations can review the entry and choose whether or not to publish that particular project on its own Web site.

  2. Simultaneous determination of quercetin, kaempferol and isorhamnetin accumulated human breast cancer cells, by high-performance liquid chromatography.

    PubMed

    Wang, Yi; Cao, Jiang; Weng, Jian-Hua; Zeng, Su

    2005-09-01

    Quercetin, kaempferol and isorhamnetin are the most important constituents in ginkgo flavonoids. A simple, rapid and sensitive high-performance liquid chromatography method was developed to simultaneously determine quercetin, kaempferol and isorhamnetin absorped by human breast cancer cells. Cells were treated with ginkgo flavonols and then lysed with Triton-X 100. The flavonols in the samples were measured by RP-HPLC with a C18 column after a simple extraction with a mixture of ether and acetone. The mobile phase contained phosphate buffer (pH 2.0; 10 mM) tetrahydrofuran, methanol and isopropanol (65:15:10:20, v/v/v/v). The ultraviolet detector was operated at 380 nm. The calibration curve was linear from 0.1 to 1.0 microM (r > 0.999) for each flavonol. The mean extraction efficiency was about 70%. The recovery of the assay was between 98.9 and 100.6%. The limit of detection was 0.01 microM for quercetin and kaempferol and 0.05 microM for isorhamnetin. The limit of quantitation was 0.1 microM (R.S.D.<10%) for each flavonol. The intra- and inter-day coefficients of variation were less than 10% (R.S.D.). The validated method was applied to quantify quercetin, kaempferol and isorhamnetin in human breast cancer Bcap37 and Bcap37/MDR1 cells.

  3. Development of real time digital holographic microscope for cell flow interactions using a High Performance Computing (HPC) cluster

    NASA Astrophysics Data System (ADS)

    Hojjati, Avesta; Molaei, Mehdi; Sheng, Jian

    2013-11-01

    Real-time imaging and analysis of 3D cell migration and locomotion is crucial to understand the underlying physics of cell environment interactions. In addition, such a microscopy would provide vital diagnostic capability in cell detection, particle sorting and drug screening with large throughput. However, 3D holographic imaging and subsequent analysis are computational intensive and up-to-date prohibitive for real-time applications. With the advances in high performance computing, we are developing a real-time digital holographic microscope (DHM) that includes an in-line DHM, a large format CCD camera, and a 24-node windows-based HPC cluster. The cluster is organized as the master-slave parallel computing paradigm with Message Passing Interface (MPI) as its communication protocol. The holograms are recorded, streamed and analyzed by the HPC cluster in real time, the 3D distributions and in focus images are rendered back on the data acquisition computer. The system will be applied to study marine protest interacting with oil droplets. Supports from GoMRI are acknowledged.

  4. Facile Fabrication of Graphene-Containing Foam as a High-Performance Anode for Microbial Fuel Cells.

    PubMed

    Yang, Lu; Wang, Shuqin; Peng, Shuqin; Jiang, Hongmei; Zhang, Youming; Deng, Wenfang; Tan, Yueming; Ma, Ming; Xie, Qingji

    2015-07-20

    Facile fabrication of novel three-dimensional anode materials to increase the bacterial loading capacity and improve substrate transport in microbial fuel cells (MFCs) is of great interest and importance. Herein, a novel graphene-containing foam (GCF) was fabricated easily by freeze-drying and pyrolysis of a graphene oxide-agarose gel. Owing to the involvement of graphene and stainless-steel mesh in the GCF, the GCF shows high electrical conductivity, enabling the GCF to be a conductive electrode for MFC applications. With the aid of agarose, the GCF electrode possesses a supermacroporous structure with pore sizes ranging from 100-200 μm and a high surface area, which greatly increase the bacterial loading capacity. Cell viability measurements indicate that the GCF possesses excellent biocompatibility. The MFC, equipped with a 0.4 mm-thick GCF anode, shows a maximum area power density of 786 mW m(-2) , which is 4.1 times that of a MFC equipped with a commercial carbon cloth anode. The simple fabrication route in combination with the outstanding electrochemical performance of the GCF indicates a promising anode for MFC applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Priority and Challenge of High-Power Performance of Low-Platinum Proton-Exchange Membrane Fuel Cells.

    PubMed

    Kongkanand, Anusorn; Mathias, Mark F

    2016-04-07

    Substantial progress has been made in reducing proton-exchange membrane fuel cell (PEMFC) cathode platinum loadings from 0.4-0.8 mgPt/cm(2) to about 0.1 mgPt/cm(2). However, at this level of cathode Pt loading, large performance loss is observed at high-current density (>1 A/cm(2)), preventing a reduction in the overall stack cost. This next developmental step is being limited by the presence of a resistance term exhibited at these lower Pt loadings and apparently due to a phenomenon at or near the catalyst surface. This issue can be addressed through the design of catalysts with high and stable Pt dispersion as well as through development and implementation of ionomers designed to interact with Pt in a way that does not constrain oxygen reduction reaction rates. Extrapolating from progress made in past decades, we are optimistic that the concerted efforts of materials and electrode designers can resolve this issue, thus enabling a large step toward fuel cell vehicles that are affordable for the mass market.

  6. High-performance method for specific effect on nucleic acids in cells using TiO2~DNA nanocomposites

    NASA Astrophysics Data System (ADS)

    Levina, Asya S.; Repkova, Marina N.; Ismagilov, Zinfer R.; Shikina, Nadezhda V.; Malygin, Ernst G.; Mazurkova, Natalia A.; Zinov'ev, Victor V.; Evdokimov, Alexei A.; Baiborodin, Sergei I.; Zarytova, Valentina F.

    2012-10-01

    Nanoparticles are used to solve the current drug delivery problem. We present a high-performance method for efficient and selective action on nucleic acid target in cells using unique TiO2.PL-DNA nanocomposites (polylysine-containing DNA fragments noncovalently immobilized onto TiO2 nanoparticles capable of transferring DNA). These nanocomposites were used for inhibition of human influenza A (H3N2) virus replication in infected MDCK cells. They showed a low toxicity (TC50 ~ 1800 μg/ml) and a high antiviral activity (>99.9% inhibition of the virus replication). The specificity factor (antisense effect) appeared to depend on the delivery system of DNA fragments. This factor for nanocomposites is ten-times higher than for DNA in the presence of lipofectamine. IC50 for nanocomposites was estimated to be 1.5 μg/ml (30 nM for DNA), so its selectivity index was calculated as ~1200. Thus, the proposed nanocomposites are prospective for therapeutic application.

  7. Performance and characteristics of a high pressure, high temperature capillary cell with facile construction for operando x-ray absorption spectroscopy

    SciTech Connect

    Bansode, Atul; Urakawa, Atsushi; Guilera, Gemma; Simonelli, Laura; Avila, Marta; Cuartero, Vera

    2014-08-15

    We demonstrate the use of commercially available fused silica capillary and fittings to construct a cell for operando X-ray absorption spectroscopy (XAS) for the study of heterogeneously catalyzed reactions under high pressure (up to 200 bars) and high temperature (up to 280 °C) conditions. As the first demonstration, the cell was used for CO{sub 2} hydrogenation reaction to examine the state of copper in a conventional Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. The active copper component of the catalyst was shown to remain in the metallic state under supercritical reaction conditions, at 200 bars and up to 260 °C. With the coiled heating system around the capillary, one can easily change the length of the capillary and control the amount of catalyst under investigation. With precise control of reactant(s) flow, the cell can mimic and serve as a conventional fixed-bed micro-reactor system to obtain reliable catalytic data. This high comparability of the reaction performance of the cell and laboratory reactors is crucial to gain insights into the nature of actual active sites under technologically relevant reaction conditions. The large length of the capillary can cause its bending upon heating when it is only fixed at both ends because of the thermal expansion. The degree of the bending can vary depending on the heating mode, and solutions to this problem are also presented. Furthermore, the cell is suitable for Raman studies, nowadays available at several beamlines for combined measurements. A concise study of CO{sub 2} phase behavior by Raman spectroscopy is presented to demonstrate a potential of the cell for combined XAS-Raman studies.

  8. Performance and characteristics of a high pressure, high temperature capillary cell with facile construction for operando x-ray absorption spectroscopy.

    PubMed

    Bansode, Atul; Guilera, Gemma; Cuartero, Vera; Simonelli, Laura; Avila, Marta; Urakawa, Atsushi

    2014-08-01

    We demonstrate the use of commercially available fused silica capillary and fittings to construct a cell for operando X-ray absorption spectroscopy (XAS) for the study of heterogeneously catalyzed reactions under high pressure (up to 200 bars) and high temperature (up to 280 °C) conditions. As the first demonstration, the cell was used for CO2 hydrogenation reaction to examine the state of copper in a conventional Cu/ZnO/Al2O3 methanol synthesis catalyst. The active copper component of the catalyst was shown to remain in the metallic state under supercritical reaction conditions, at 200 bars and up to 260 °C. With the coiled heating system around the capillary, one can easily change the length of the capillary and control the amount of catalyst under investigation. With precise control of reactant(s) flow, the cell can mimic and serve as a conventional fixed-bed micro-reactor system to obtain reliable catalytic data. This high comparability of the reaction performance of the cell and laboratory reactors is crucial to gain insights into the nature of actual active sites under technologically relevant reaction conditions. The large length of the capillary can cause its bending upon heating when it is only fixed at both ends because of the thermal expansion. The degree of the bending can vary depending on the heating mode, and solutions to this problem are also presented. Furthermore, the cell is suitable for Raman studies, nowadays available at several beamlines for combined measurements. A concise study of CO2 phase behavior by Raman spectroscopy is presented to demonstrate a potential of the cell for combined XAS-Raman studies.

  9. High Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Talcott, Stephen

    High performance liquid chromatography (HPLC) has many applications in food chemistry. Food components that have been analyzed with HPLC include organic acids, vitamins, amino acids, sugars, nitrosamines, certain pesticides, metabolites, fatty acids, aflatoxins, pigments, and certain food additives. Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile. It is necessary, however, for the compounds to have some solubility in the mobile phase. It is important that the solubilized samples for injection be free from all particulate matter, so centrifugation and filtration are common procedures. Also, solid-phase extraction is used commonly in sample preparation to remove interfering compounds from the sample matrix prior to HPLC analysis.

  10. Towards high performance computing for molecular structure prediction using IBM Cell Broadband Engine--an implementation perspective.

    PubMed

    Krishnan, S P T; Liang, Sim Sze; Veeravalli, Bharadwaj

    2010-01-18

    RNA structure prediction problem is a computationally complex task, especially with pseudo-knots. The problem is well-studied in existing literature and predominantly uses highly coupled Dynamic Programming (DP) solutions. The problem scale and complexity become embarrassingly humungous to handle as sequence size increases. This makes the case for parallelization. Parallelization can be achieved by way of networked platforms (clusters, grids, etc) as well as using modern day multi-core chips. In this paper, we exploit the parallelism capabilities of the IBM Cell Broadband Engine to parallelize an existing Dynamic Programming (DP) algorithm for RNA secondary structure prediction. We design three different implementation strategies that exploit the inherent data, code and/or hybrid parallelism, referred to as C-Par, D-Par and H-Par, and analyze their performances. Our approach attempts to introduce parallelism in critical sections of the algorithm. We ran our experiments on SONY Play Station 3 (PS3), which is based on the IBM Cell chip. Our results suggest that introducing parallelism in DP algorithm allows it to easily handle longer sequences which otherwise would consume a large amount of time in single core computers. The results further demonstrate the speed-up gain achieved in exploiting the inherent parallelism in the problem and also elicits the advantages of using multi-core platforms towards designing more sophisticated methodologies for handling a fairly long sequence of RNA. The speed-up performance reported here is promising, especially when sequence length is long. To the best of our literature survey, the work reported in this paper is probably the first-of-its-kind to utilize the IBM Cell Broadband Engine (a heterogeneous multi-core chip) to implement a DP. The results also encourage using multi-core platforms towards designing more sophisticated methodologies for handling a fairly long sequence of RNA to predict its secondary structure.

  11. High temperature polymer electrolyte membrane fuel cell performance of Pt xCo y/C cathodes

    NASA Astrophysics Data System (ADS)

    Rao, Ch. Venkateswara; Parrondo, Javier; Ghatty, Sundara L.; Rambabu, B.

    Carbon-supported Pt-Co alloy nanoparticles of varying Pt:Co atomic ratios of 1:1, 2:1, 3:1 and 4:1 are prepared, characterized and tested in high temperature PEM fuel cell intend to reduce the Pt loading. These electrocatalysts are prepared by borohydride reduction method in the presence of citric acid as stabilizing agent. Face-centered cubic structure of Pt is evident from XRD. The positive shift of Pt diffraction peaks with increasing cobalt content in the Pt xCo y/C catalysts indicated the solubility of Co in Pt lattice. The average crystallite size is found to be 6 nm in all the prepared catalysts. The electrochemical active surface area (EAS) of the catalysts from CO-stripping voltammetry is calculated to be 65.2, 51.4, 47.7, 41.5 and 38.3 m 2 g -1 Pt for Pt/C, Pt-Co(4:1)/C, Pt-Co(3:1)/C, Pt-Co(2:1)/C and Pt-Co(1:1)/C, respectively. These catalysts are used as cathode in the fabrication of polybenzimidazole-based membrane electrode assembly (MEA) and the polarization curves are recorded at 160 and 180 °C. The results indicate the good performance of Pt-Co alloys than that of Pt under the PEM fuel cell conditions. Among the investigated electrocatalysts, Pt-Co(1:1)/C and Pt-Co(2:1)/C exhibited good fuel cell performance. Durability tests also indicated the good stability of Pt-Co(1:1)/C and Pt-Co(2:1)/C compared to Pt/C.

  12. Cross-linked high conductive membranes based on water soluble ionomer for high performance proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Jiang, Hao; Guo, Xin; Zhang, Gang; Ni, Jing; Zhao, Chengji; Liu, Zhongguo; Zhang, Liyuan; Li, Mingyu; Xu, Shuai; Na, Hui

    2013-11-01

    In this paper, a series of proton exchange membranes prepared by “Click Reaction” are reported. The cross-linked membranes are based on water soluble sulfonated poly (ether ether ketone) containing dipropenyl groups (SDPEEK-nE/nH). Compared with self-crosslinked membranes (SDPEEK-nS), this “Click” cross-linked membranes using 1,2-Ethanedithiol and 1,6-Hexanedithiol as the cross-linker exhibit extremely reduced water uptake and swelling ratio. The lowest proton conductivity at 80 °C of the “Click” cross-linked membranes reaches to 0.168 S cm-1, and the highest methanol permeability of the “Click” cross-linked SDPEEK-8E is only 4.13 × 10-7 cm2 s-1, which is 5 times lower than that of Nafion 117 membrane. All the results imply that the cross-linked membranes with novel thiol cross-linker are promising alternative material for fuel cell application.

  13. Altus small button cell performance

    NASA Technical Reports Server (NTRS)

    Freeman, C.; Bis, F.; Warbutton, D. L.

    1981-01-01

    Results of testing performed on Altus lithium thionyl chloride cells are presented. The test plan followed simulates the mine environment. It involves nondestructive testing, ruggedness testing and destructive testing. The nondestructive testing involves open circuit voltage measurements initially on all the cells, alternating current resistance measurements initially on all the cells and closed circuit voltage pulses, 20s on and 20s through 1000, 100, 10 and 1 ohms at temperatures of -54 to 71 C. The ruggedness testing involves low frequency vibration, high frequency vibration, and two-phase water entry shock at temperatures of -54, 25 and 71 C. It also involves thermal shock tests.

  14. Robust High-performance Dye-sensitized Solar Cells Based on Ionic Liquid-sulfolane Composite Electrolytes

    PubMed Central

    Lau, Genevieve P. S.; Décoppet, Jean-David; Moehl, Thomas; Zakeeruddin, Shaik M.; Grätzel, Michael; Dyson, Paul J.

    2015-01-01

    Novel ionic liquid-sulfolane composite electrolytes based on the 1,2,3-triazolium family of ionic liquids were developed for dye-sensitized solar cells. The best performing device exhibited a short-circuit current density of 13.4 mA cm−2, an open-circuit voltage of 713 mV and a fill factor of 0.65, corresponding to an overall power conversion efficiency (PCE) of 6.3%. In addition, these devices are highly stable, retaining more than 95% of the initial device PCE after 1000 hours of light- and heat-stress. These composite electrolytes show great promise for industrial application as they allow for a 14.5% improvement in PCE, compared to the solvent-free eutectic ionic liquid electrolyte system, without compromising device stability. PMID:26670595

  15. Robust High-performance Dye-sensitized Solar Cells Based on Ionic Liquid-sulfolane Composite Electrolytes

    NASA Astrophysics Data System (ADS)

    Lau, Genevieve P. S.; Décoppet, Jean-David; Moehl, Thomas; Zakeeruddin, Shaik M.; Grätzel, Michael; Dyson, Paul J.

    2015-12-01

    Novel ionic liquid-sulfolane composite electrolytes based on the 1,2,3-triazolium family of ionic liquids were developed for dye-sensitized solar cells. The best performing device exhibited a short-circuit current density of 13.4 mA cm-2, an open-circuit voltage of 713 mV and a fill factor of 0.65, corresponding to an overall power conversion efficiency (PCE) of 6.3%. In addition, these devices are highly stable, retaining more than 95% of the initial device PCE after 1000 hours of light- and heat-stress. These composite electrolytes show great promise for industrial application as they allow for a 14.5% improvement in PCE, compared to the solvent-free eutectic ionic liquid electrolyte system, without compromising device stability.

  16. Single-Crystal-like Perovskite for High-Performance Solar Cells Using the Effective Merged Annealing Method.

    PubMed

    Liu, Yanliang; Shin, Insoo; Hwang, In-Wook; Kim, Seungmin; Lee, Jihoon; Yang, Mi-Sun; Jung, Yun Kyung; Jang, Jae-Won; Jeong, Jung Hyun; Park, Sung Heum; Kim, Kwang Ho

    2017-04-12

    We report a simple, low cost, and quite effective method for achieving single-crystal-like CH3NH3PbI3 perovskite leading to a significant enhancement in the performance and stability of inverted planar perovskite solar cells (IPSCs). By employing a merged annealing method during the fabrication of an IPSC for preparing the perovskite CH3NH3PbI3 film, we remarkably increase the crystallinity of the CH3NH3PbI3 film and enhance the device performance and stability. An IPSC with the indium tin oxide/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/CH3NH3PbI3 (active layer)/[6,6]-phenyl-C61-butyric acid methyl ester/Al structure was fabricated using the merged annealing method and exhibited significantly enhanced performance with a high power conversion efficiency of 18.27% and a fill factor of 81.34%. Moreover, since two separate annealing processes are merged in the proposed annealing method, the fabrication step becomes much simpler and easier, leading to a reduction in fabrication costs.

  17. A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock

    SciTech Connect

    François, B.; Boudot, R.; Calosso, C. E.; Danet, J. M.

    2014-09-15

    We report the development, absolute phase noise, and residual phase noise characterization of a 9.192 GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192 GHz output signal are measured to be −42, −100, −117 dB rad{sup 2}/Hz and −129 dB rad{sup 2}/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10{sup −14} at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.

  18. A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock.

    PubMed

    François, B; Calosso, C E; Danet, J M; Boudot, R

    2014-09-01

    We report the development, absolute phase noise, and residual phase noise characterization of a 9.192 GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192 GHz output signal are measured to be -42, -100, -117 dB rad(2)/Hz and -129 dB rad(2)/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10(-14) at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.

  19. A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock

    NASA Astrophysics Data System (ADS)

    François, B.; Calosso, C. E.; Danet, J. M.; Boudot, R.

    2014-09-01

    We report the development, absolute phase noise, and residual phase noise characterization of a 9.192 GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192 GHz output signal are measured to be -42, -100, -117 dB rad2/Hz and -129 dB rad2/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10-14 at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.

  20. High-Performance Platinum-Free Dye-Sensitized Solar Cells with Molybdenum Disulfide Films as Counter Electrodes.

    PubMed

    Hussain, Sajjad; Shaikh, Shoyebmohamad F; Vikraman, Dhanasekaran; Mane, Rajaram S; Joo, Oh-Shim; Naushad, Mu; Jung, Jongwan

    2015-12-21

    By using a radio-frequency sputtering method, we synthesized large-area, uniform, and transparent molybdenum disulfide film electrodes (1, 3, 5, and 7 min) on transparent and conducting fluorine-doped tin oxide (FTO), as ecofriendly, cost-effective counter electrodes (CE) for dye-sensitized solar cells (DSSCs). These CEs were used in place of the routinely used expensive platinum CEs for the catalytic reduction of a triiodide electrolyte. The structure and morphology of the MoS2 was analyzed by using Raman spectroscopy, X-ray diffraction, and X-ray photoemission spectroscopy measurements and the DSSC characteristics were investigated. An unbroken film of MoS2 was identified on the FTO crystallites from field-emission scanning electron microscopy. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curve measurements reveal the promise of MoS2 as a CE with a low charge-transfer resistance, high electrocatalytic activity, and fast reaction kinetics for the reduction of triiodide to iodide. Finally, an optimized transparent MoS2 CE, obtained after 5 min synthesis time, showed a high power-conversion efficiency of 6.0 %, which comparable to the performance obtained with a Pt CE (6.6 %) when used in TiO2 -based DSCCs, thus signifying the importance of sputtering time on DSSC performance. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Advanced Cd(II) complexes as high efficiency co-sensitizers for enhanced dye-sensitized solar cell performance.

    PubMed

    Gao, Song; Fan, Rui Qing; Wang, Xin Ming; Qiang, Liang Sheng; Wei, Li Guo; Wang, Ping; Yang, Yu Lin; Wang, Yu Lei

    2015-11-07

    This work reports on two new complexes with the general formula [Cd3(IBA)3(Cl)2(HCOO)(H2O)]n (1) and {[Cd1.5(IBA)3(H2O)6]·3.5H2O}n (2), which can be synthesized by the reaction of Cd(II) with rigid linear ligand 4-HIBA containing imidazolyl and carboxylate functional groups [4-HIBA = 4-(1H-imidazol-1-yl)benzoic acid]. Single-crystal X-ray diffraction analyses indicate that complex 1 is a 2D "wave-like" layer structure constructed from trinuclear units and complex 2 is just a mononuclear structure. Surprisingly, both complexes 1 and 2 appear as a 3D supramolecular network via intermolecular hydrogen bonding interactions. What's more, due to their strong UV-visible absorption, 1 and 2 can be employed as co-sensitizers in combination with N719 to enhance dye-sensitized solar cell (DSSC) performance. Both of them could overcome the deficiency of the ruthenium complex N719 absorption in the region of ultraviolet and blue-violet, and the charge collection efficiency is also improved when 1 and 2 are used as co-sensitizers, which are all in favor of enhancing the performance. The DSSC devices using co-sensitizers of 1/N719 and 2/N719 show an overall conversion efficiency of 8.27% and 7.73% with a short circuit current density of 17.48 mA cm(-2) and 17.39 mA cm(-2), and an open circuit voltage of 0.75 V and 0.74 V, respectively. The overall conversion efficiency is 27.23% and 18.92% higher than that of a device solely sensitized by N719 (6.50%). Consequently, the prepared complexes are high efficiency co-sensitizers for enhancing the performance of N719 sensitized solar cells.

  2. Why do proton conducting polybenzimidazole phosphoric acid membranes perform well in high-temperature PEM fuel cells?

    PubMed

    Melchior, Jan-Patrick; Majer, Günter; Kreuer, Klaus-Dieter

    2016-12-21

    Transport properties and hydration behavior of phosphoric acid/(benz)imidazole mixtures are investigated by diverse NMR techniques, thermogravimetric analysis (TGA) and conductivity measurements. The monomeric systems can serve as models for phosphoric acid/poly-benzimidazole membranes which are known for their exceptional performance in high temperature PEM fuel cells. (1)H- and (31)P-NMR data show benzimidazole acting as a strong Brønsted base with respect to neat phosphoric acid. Since benzimidazole's nitrogens are fully protonated with a low rate for proton exchange with phosphate species, proton diffusion and conduction processes must take place within the hydrogen bond network of phosphoric acid only. The proton exchange dynamics between phosphate and benzimidazole species pass through the intermediate exchange regime (with respect to NMR line separations) with exchange times being close to typical diffusion times chosen in PFG-NMR diffusion measurements (ms regime). The resulting effects, as described by the Kärger equation, are included into the evaluation of PFG-NMR data for obtaining precise proton diffusion coefficients. The highly reduced proton diffusion coefficient within the phosphoric acid part of the model systems compared to neat phosphoric acid is suggested to be the immediate consequence of proton subtraction from phosphoric acid. This reduces hydrogen bond network frustration (imbalance of the number of proton donors and acceptors) and therefore also the rate of structural proton diffusion, phosphoric acid's acidity and hygroscopicity. Reduced water uptake, shown by TGA, goes along with reduced electroosmotic water drag which is suggested to be the reason for PBI-phosphoric acid membranes performing better in fuel cells than other phosphoric-acid-containing electrolytes with higher protonic conductivity.

  3. High Performance Parallel Architectures

    NASA Technical Reports Server (NTRS)

    El-Ghazawi, Tarek; Kaewpijit, Sinthop

    1998-01-01

    Traditional remote sensing instruments are multispectral, where observations are collected at a few different spectral bands. Recently, many hyperspectral instruments, that can collect observations at hundreds of bands, have been operational. Furthermore, there have been ongoing research efforts on ultraspectral instruments that can produce observations at thousands of spectral bands. While these remote sensing technology developments hold great promise for new findings in the area of Earth and space science, they present many challenges. These include the need for faster processing of such increased data volumes, and methods for data reduction. Dimension Reduction is a spectral transformation, aimed at concentrating the vital information and discarding redundant data. One such transformation, which is widely used in remote sensing, is the Principal Components Analysis (PCA). This report summarizes our progress on the development of a parallel PCA and its implementation on two Beowulf cluster configuration; one with fast Ethernet switch and the other with a Myrinet interconnection. Details of the implementation and performance results, for typical sets of multispectral and hyperspectral NASA remote sensing data, are presented and analyzed based on the algorithm requirements and the underlying machine configuration. It will be shown that the PCA application is quite challenging and hard to scale on Ethernet-based clusters. However, the measurements also show that a high- performance interconnection network, such as Myrinet, better matches the high communication demand of PCA and can lead to a more efficient PCA execution.

  4. High Performance Parallel Architectures

    NASA Technical Reports Server (NTRS)

    El-Ghazawi, Tarek; Kaewpijit, Sinthop

    1998-01-01

    Traditional remote sensing instruments are multispectral, where observations are collected at a few different spectral bands. Recently, many hyperspectral instruments, that can collect observations at hundreds of bands, have been operational. Furthermore, there have been ongoing research efforts on ultraspectral instruments that can produce observations at thousands of spectral bands. While these remote sensing technology developments hold great promise for new findings in the area of Earth and space science, they present many challenges. These include the need for faster processing of such increased data volumes, and methods for data reduction. Dimension Reduction is a spectral transformation, aimed at concentrating the vital information and discarding redundant data. One such transformation, which is widely used in remote sensing, is the Principal Components Analysis (PCA). This report summarizes our progress on the development of a parallel PCA and its implementation on two Beowulf cluster configuration; one with fast Ethernet switch and the other with a Myrinet interconnection. Details of the implementation and performance results, for typical sets of multispectral and hyperspectral NASA remote sensing data, are presented and analyzed based on the algorithm requirements and the underlying machine configuration. It will be shown that the PCA application is quite challenging and hard to scale on Ethernet-based clusters. However, the measurements also show that a high- performance interconnection network, such as Myrinet, better matches the high communication demand of PCA and can lead to a more efficient PCA execution.

  5. Solvothermal Synthesis of Hierarchical TiO2 Microstructures with High Crystallinity and Superior Light Scattering for High-Performance Dye-Sensitized Solar Cells.

    PubMed

    Li, Zhao-Qian; Mo, Li-E; Chen, Wang-Chao; Shi, Xiao-Qiang; Wang, Ning; Hu, Lin-Hua; Hayat, Tasawar; Alsaedi, Ahmed; Dai, Song-Yuan

    2017-09-20

    In this article, hierarchical TiO2 microstructures (HM-TiO2) were synthesized by a simple solvothermal method adopting tetra-n-butyl titanate as the titanium source in a mixed solvent composed of N,N-dimethylformamide and acetic acid. Due to the high crystallinity and superior light-scattering ability, the resultant HM-TiO2 are advantageous as photoanodes for dye-sensitized solar cells. When assembled to the entire photovoltaic device with C101 dye as a sensitizer, the pure HM-TiO2-based solar cells showed an ultrahigh photovoltage up to 0.853 V. Finally, by employing the as-obtained HM-TiO2 as the scattering layer and optimizing the architecture of dye-sensitized solar cells, both higher photovoltage and incident photon-to-electron conversion efficiency value were harvested with respect to TiO2 nanoparticles-based dye-sensitized solar cells, resulting in a high power conversion efficiency of 9.79%. This work provides a promising strategy to develop photoanode materials with outstanding photoelectric conversion performance.

  6. High Performance Work Practices and Firm Performance.

    ERIC Educational Resources Information Center

    Department of Labor, Washington, DC. Office of the American Workplace.

    A literature survey established that a substantial amount of research has been conducted on the relationship between productivity and the following specific high performance work practices: employee involvement in decision making, compensation linked to firm or worker performance, and training. According to these studies, high performance work…

  7. Wide band gap solar cells with high stabilized performance. Annual technical report, 15 July 1995--15 July 1996

    SciTech Connect

    Wronski, C R; Collins, R W; Fujiwara, H

    1997-01-01

    This report describes work on an improved understanding of stability in materials and silicon solar cells. Topics include novel intrinsic materials optimization; solar cells optimized for p- and i-layer performance; novel p-type materials; interfaces; and device modeling.

  8. High-performance, low Pt content catalysts for the electroreduction of oxygen in polymer-electrolyte fuel cells

    SciTech Connect

    Fournier, J.; Faubert, G.; Tilquin, J.Y.; Cote, R.; Guay, D.; Dodelet, J.P.

    1997-01-01

    Pt-included and Pt-supported catalysts have been synthesized using graphite and carbon black supports of various specific areas. The graphites are KS6 (20 m{sup 2}/g), HS100 (110 m{sup 2}/g), and HS300 (305 m{sup 2}/g) from Lonza, and the carbon blacks are Vulcan (254 m{sup 2}/g) and Black Pearls (1475 m{sup 2}/g) from Cabot. The Pt-included and Pt-supported catalysts were used at the cathode of a H{sub 2}/O{sub 2} fuel cell, and their polarization curves were compared to each other and to those of various Pt-supported catalysts from E-TEK. In the high current region of interest to fuel cell developers, it is shown that Pt-supported catalysts perform better than Pt-included ones when the specific area of the support is small. The contrary is true when the specific area of the support is large. The best catalysts are HS300-Pti [8.3 weight percent (w/o) Pt included in HS300 graphite] and Vu-Pti (6.1 w/o Pt included in Vulcan XC-72R). These catalysts display very high mass and specific activities for O{sub 2} reduction. Furthermore, the iR-corrected polarization curves of both HS300-Pti (with a Pt loading of 0.110 mg/cm{sup 2}) and Vu-Pti (with a Pt loading of 0.070 mg/cm{sup 2}) cross at high current the polarization curve of the electrode prepared with E-TEK20 (20 w/o of supported Pt, with a Pt loading of 0.287 mg/cm{sup 2}). Pt inclusion in graphite or carbon black is therefore an interesting way of reducing the Pt loading of fuel cell cathodes without lowering electrochemical performance. HS300-Pti have been characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. These analyses indicate that they both contain metallic Pt and Pt(II and IV) oxides and/or hydroxides.

  9. High performance sapphire windows

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.; Liou, Larry

    1993-01-01

    High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

  10. Sustainable design of high-performance microsized microbial fuel cell with carbon nanotube anode and air cathode.

    PubMed

    Mink, Justine E; Hussain, Muhammad Mustafa

    2013-08-27

    Microbial fuel cells (MFCs) are a promising alternative energy source that both generates electricity and cleans water. Fueled by liquid wastes such as wastewater or industrial wastes, the microbial fuel cell converts waste into energy. Microsized MFCs are essentially miniature energy harvesters that can be used to power on-chip electronics, lab-on-a-chip devices, and/or sensors. As MFCs are a relatively new technology, microsized MFCs are also an important rapid testing platform for the comparison and introduction of new conditions or materials into macroscale MFCs, especially nanoscale materials that have high potential for enhanced power production. Here we report a 75 μL microsized MFC on silicon using CMOS-compatible processes and employ a novel nanomaterial with exceptional electrochemical properties, multiwalled carbon nanotubes (MWCNTs), as the on-chip anode. We used this device to compare the usage of the more commonly used but highly expensive anode material gold, as well as a more inexpensive substitute, nickel. This is the first anode material study done using the most sustainably designed microsized MFC to date, which utilizes ambient oxygen as the electron acceptor with an air cathode instead of the chemical ferricyanide and without a membrane. Ferricyanide is unsustainable, as the chemical must be continuously refilled, while using oxygen, naturally found in air, makes the device mobile and is a key step in commercializing this for portable technology such as lab-on-a-chip for point-of-care diagnostics. At 880 mA/m(2) and 19 mW/m(2) the MWCNT anode outperformed the others in both current and power densities with between 6 and 20 times better performance. All devices were run for over 15 days, indicating a stable and high-endurance energy harvester already capable of producing enough power for ultra-low-power electronics and able to consistently power them over time.

  11. A natural carbonized leaf as polysulfide diffusion inhibitor for high-performance lithium-sulfur battery cells.

    PubMed

    Chung, Sheng-Heng; Manthiram, Arumugam

    2014-06-01

    Attracted by the unique tissue and functions of leaves, a natural carbonized leaf (CL) is presented as a polysulfide diffusion inhibitor in lithium-sulfur (Li-S) batteries. The CL that is covered on the pure sulfur cathode effectively suppresses the polysulfide shuttling mechanism and enables the use of pure sulfur as the cathode. A low charge resistance and a high discharge capacity of 1320 mA h g(-1) arise from the improved cell conductivity due to the innately integral conductive carbon network of the CL. The unique microstructure of CL leads to a high discharge/charge efficiency of >98 %, low capacity fade of 0.18 % per cycle, and good long-term cyclability over 150 cycles. The structural gradient and the micro/mesoporous adsorption sites of CL effectively intercept/trap the migrating polysulfides and facilitate their reutilization. The green CL polysulfide diffusion inhibitor thus offers a viable approach for developing high-performance lithium-sulfur batteries. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Carbon nanotube/metal-sulfide composite flexible electrodes for high-performance quantum dot-sensitized solar cells and supercapacitors

    PubMed Central

    Muralee Gopi, Chandu V. V.; Ravi, Seenu; Rao, S. Srinivasa; Eswar Reddy, Araveeti; Kim, Hee-Je

    2017-01-01

    Carbon nanotubes (CNT) and metal sulfides have attracted considerable attention owing to their outstanding properties and multiple application areas, such as electrochemical energy conversion and energy storage. Here we describes a cost-effective and facile solution approach to the preparation of metal sulfides (PbS, CuS, CoS, and NiS) grown directly on CNTs, such as CNT/PbS, CNT/CuS, CNT/CoS, and CNT/NiS flexible electrodes for quantum dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs). X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy confirmed that the CNT network was covered with high-purity metal sulfide compounds. QDSSCs equipped with the CNT/NiS counter electrode (CE) showed an impressive energy conversion efficiency (η) of 6.41% and remarkable stability. Interestingly, the assembled symmetric CNT/NiS-based polysulfide SC device exhibited a maximal energy density of 35.39 W h kg−1 and superior cycling durability with 98.39% retention after 1,000 cycles compared to the other CNT/metal-sulfides. The elevated performance of the composites was attributed mainly to the good conductivity, high surface area with mesoporous structures and stability of the CNTs and the high electrocatalytic activity of the metal sulfides. Overall, the designed composite CNT/metal-sulfide electrodes offer an important guideline for the development of next level energy conversion and energy storage devices. PMID:28422182

  13. Tuning the architectural integrity of high-performance magneto-fluorescent core-shell nanoassemblies in cancer cells.

    PubMed

    Faucon, Adrien; Benhelli-Mokrani, Houda; Fleury, Fabrice; Dubreil, Laurence; Hulin, Philippe; Nedellec, Steven; Doussineau, Tristan; Antoine, Rodolphe; Orlando, Tomas; Lascialfari, Alessandro; Fresnais, Jérôme; Lartigue, Lénaïc; Ishow, Eléna

    2016-10-01

    High-density nanoarchitectures, endowed with simultaneous fluorescence and contrast properties for MRI and TEM imaging, have been obtained using a simple self-assembling strategy based on supramolecular interactions between non-doped fluorescent organic nanoparticles (FON) and superparamagnetic nanoparticles. In this way, a high-payload core-shell structure FON@mag has been obtained, protecting the hydrophobic fluorophores from the surroundings as well as from emission quenching by the shell of magnetic nanoparticles. Compared to isolated nanoparticles, maghemite nanoparticles self-assembled as an external shell create large inhomogeneous magnetic field, which causes enhanced transverse relaxivity and exacerbated MRI contrast. The magnetic load of the resulting nanoassemblies is evaluated using magnetic sedimentation and more originally electrospray mass spectrometry. The role of the stabilizing agents (citrate versus polyacrylate anions) revealed to be crucial regarding the cohesion of the resulting high-performance magneto-fluorescent nanoassemblies, which questions their use after cell internalization as nanocarriers or imaging agents for reliable correlative light and electron microcopy.

  14. Carbon nanotube/metal-sulfide composite flexible electrodes for high-performance quantum dot-sensitized solar cells and supercapacitors

    NASA Astrophysics Data System (ADS)

    Muralee Gopi, Chandu V. V.; Ravi, Seenu; Rao, S. Srinivasa; Eswar Reddy, Araveeti; Kim, Hee-Je

    2017-04-01

    Carbon nanotubes (CNT) and metal sulfides have attracted considerable attention owing to their outstanding properties and multiple application areas, such as electrochemical energy conversion and energy storage. Here we describes a cost-effective and facile solution approach to the preparation of metal sulfides (PbS, CuS, CoS, and NiS) grown directly on CNTs, such as CNT/PbS, CNT/CuS, CNT/CoS, and CNT/NiS flexible electrodes for quantum dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs). X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy confirmed that the CNT network was covered with high-purity metal sulfide compounds. QDSSCs equipped with the CNT/NiS counter electrode (CE) showed an impressive energy conversion efficiency (η) of 6.41% and remarkable stability. Interestingly, the assembled symmetric CNT/NiS-based polysulfide SC device exhibited a maximal energy density of 35.39 W h kg-1 and superior cycling durability with 98.39% retention after 1,000 cycles compared to the other CNT/metal-sulfides. The elevated performance of the composites was attributed mainly to the good conductivity, high surface area with mesoporous structures and stability of the CNTs and the high electrocatalytic activity of the metal sulfides. Overall, the designed composite CNT/metal-sulfide electrodes offer an important guideline for the development of next level energy conversion and energy storage devices.

  15. Unsubstituted Benzodithiophene-Based Conjugated Polymers for High-Performance Organic Field-Effect Transistors and Organic Solar Cells.

    PubMed

    Chen, Weichao; Xiao, Manjun; Han, Liangliang; Zhang, Jidong; Jiang, Huanxiang; Gu, Chuantao; Shen, Wenfei; Yang, Renqiang

    2016-08-03

    Unsubstituted benzo[1,2-b:4,5-b']dithiophene (BDT) was used to construct a high-performance conjugated polymer with 5,6-difluoro-4,7-bis[4-(2-octyldodecyl)thiophene-2-yl]benzo[c][1,2,5] thiadiazole (DTFFBT), named PBDT-DTFFBT. The polymer shows the low-lying highest occupied molecular orbital (HOMO) energy level (-5.40 eV) and a broad absorption spectra with strong vibronic absorption peak. Pure polymer films exhibit good crystallinity and edge-on orientation, partially attributed to the BDT units without any side chains, and as a result, the corresponding thin-film transistor showed excellent hole mobility over 1 cm(2) V(-1) s(-1). Interestingly, a well-distributed nanofibrillar polymer aggregation with face-on orientation was obviously formed when blending with PC71BM, which was in favor of the charge transportation. Consequently, the bulk heterojunction polymer solar cells based on the blends showed high power conversion efficiency of 9.29% with large short-current density (14.56 mA cm(-2)) and high fill factor (0.751) without any process additives or thermal annealing.

  16. Enhancement of the fuel cell performance of a high temperature proton exchange membrane fuel cell running with titanium composite polybenzimidazole-based membranes

    NASA Astrophysics Data System (ADS)

    Lobato, Justo; Cañizares, Pablo; Rodrigo, Manuel A.; Úbeda, Diego; Pinar, F. Javier

    2011-10-01

    The fuel cell performance of a composite PBI-based membrane with TiO2 has been studied. The behaviour of the membrane has been evaluated by comparison with the fuel cell performance of other PBI-based membranes, all of which were cast from the same polymer with the same molecular weight. The PBI composite membrane incorporating TiO2 showed the best performance and reached 1000 mW cm-2 at 175 °C. Moreover, this new titanium composite PBI-based membrane also showed the best stability during the preliminary long-term test under our operation conditions. Thus, the slope of the increase in the ohmic resistance of the composite membrane was 0.041 mΩ cm2 h-1 and this is five times lower than that of the standard PBI membrane. The increased stability was due to the high phosphoric acid retention capacity - as confirmed during leaching tests, in which the Ti-based composite PBI membrane retained 5 mol of H3PO4/PBI r.u. whereas the PBI standard membrane only retained 1 mol H3PO4/PBI r.u. Taking into account the results obtained in this study, the TiO2-PBI based membranes are good candidates as electrolytes for high temperature PEMFCs.

  17. High performing micromachined retroreflector

    NASA Astrophysics Data System (ADS)

    Lundvall, Axel; Nikolajeff, Fredrik; Lindstrom, Tomas

    2003-10-01

    This paper reports on the realization of a type of micromachined retroreflecting sheeting material. The geometry presented has high reflection efficiency even at large incident angles, and it can be manufactured through polymer replication techniques. The paper consists of two parts: A theoretical section outlining the design parameters and their impact on the optical performance, and secondly, an experimental part comprising both manufacturing and optical evaluation for a candidate retroreflecting sheet material in traffic control devices. Experimental data show that the retroreflecting properties are promising. The retroreflector consists of a front layer of densely packed spherical microlenses, a back surface of densely packed spherical micromirrors, and a transparent spacer layer. The thickness of the spacer layer determines in part the optical characteristics of the retroreflector.

  18. Application of high-performance liquid chromatographic methodology to the analysis of hemoglobins synthesized in erythroid progenitor cells.

    PubMed

    Bhaumik, K; Huisman, T H

    1989-11-10

    High-performance liquid chromatography (HPLC) has been successfully used in the quantitation of the relatively minute amounts of hemoglobin types recovered from in vitro cultures of hemoglobin-synthesizing erythroid progenitor (BFU-E) cells. This reversed-phase HPLC method uses the Vydac C4 column and water-acetonitrile-trifluoroacetic acid as mobile phases; it has been applied to the study of fetal hemoglobin synthesis patterns in ten homozygous sickle cell anemia patients and a similar number of their heterozygous relatives along with a few normal control subjects. A significant increase in the total gamma chain level was observed in the BFU-E lysate samples corresponding to the whole blood lysates of all the patients and their heterozygous relatives, except in one patient with the beta S haplotype Mor. On the other hand, the relative level of the G gamma chains appeared to be decreased in the BFU-E lysate samples of all except the individuals carrying the Mor haplotype, where it is reversed. The method has considerable advantages over other chromatographic and electrophoretic procedures; it is extremely sensitive and allows quantitation of all different globin chains in one single chromatogram.

  19. Metal-Organic-Compound-Modified MoS2 with Enhanced Solubility for High-Performance Perovskite Solar Cells.

    PubMed

    Dai, Ruina; Wang, Yangyang; Wang, Jie; Deng, Xianyu

    2017-07-21

    MoS2 as a graphene-like 2 D material shows a large potential to replace and even overcome graphene in various important applications owing to its ideal properties of electrical, optical, frictional, and tunable band gap. However, its low solubility in the most of common solvents makes it difficult to prepare by a simple solution process. Here, we introduce a metal-organic compound to modify MoS2 . Phenyl acetylene silver (PAS)-functionalized MoS2 is easily dispersed in solvents like DMF and water. A conductive polymer PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) blend with the MoS2 leads to a significant enhancement of the performance of planar heterojunction perovskite solar cells. The solar cells have a high power conversion efficiency of 16.47 % as well as largely increased stability. This provides a feasible method for large-scale production of MoS2 for wide applications in various electric devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Effect of the catalytic ink preparation method on the performance of high temperature polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Lobato, J.; Rodrigo, M. A.; Linares, J. J.; Scott, K.

    Two methods of preparation of the membrane-electrode-assemblies based on polybenzimidazole membranes have been studied for high temperatures PEMFCs. One is called the "colloidal method" (using acetone as solvent), and the other is the "solution method" (using dimethylacetamide as solvent). Physical property studies (SEM micrographs and pore size distribution) and electrochemical analyses in half-cell (Electrochemical Impedance Spectroscopy, Polarization Curves for Oxygen Reduction and Cyclic Voltammetry) were carried out to characterise the structural and electrochemical behaviour of both methods. Finally, a cell performance investigation, using electrodes prepared by both methods was carried out at three different temperatures (125, 150, and 175 °C), in a single PEMFC setup. A better behaviour was obtained for the "solution method" at the two highest temperatures at intermediate current densities, whereas at 125 °C the best results were obtained with the "colloidal method" in all the current densities ranges. A discussion of the behaviours observed with the different characterisation techniques is made.

  1. Binder-free carbon black/stainless steel mesh composite electrode for high-performance anode in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Zheng, Suqi; Yang, Fangfang; Chen, Shuiliang; Liu, Lang; Xiong, Qi; Yu, Ting; Zhao, Feng; Schröder, Uwe; Hou, Haoqing

    2015-06-01

    Carbon black/stainless steel mesh (CB/SSM) composite electrodes were developed as high-performance anodes of microbial fuel cell (MFC) by using a binder-free dipping/drying method. The acid-treatment and thin layer of CB coating greatly improved the microbial adhesion of the electrode surface and facilitated the electron transfer between the bacteria and the electrode surface. As a result, a single-layer CB/SSM anode with thickness of 0.3 mm could generate a projected current density of about 1.53 ± 0.15 mA cm-2 and volumetic current density of 51.0 ± 5.0 mA cm-3, which was much higher than that of the bare SSM anode and conventional carbon felt anode with thickness of 2 mm. Moreover, three-dimensional (3D) CB/SSM electrode could be prepared by simple folding the singe-layer SSM, and produced a projected current density to 10.07 ± 0.88 mA cm-2 and a volumetric current density of 18.66 ± 1.63 mA cm-3. The MFC equipped with the 3D-CB/SSM anode produced a high maximum power density of 3215 ± 80 mW m-2. The CB/SSM electrodes showed good mechanical and electrical properties, excellent microbial adhesion; it represented a high-performance, low-cost electrode material that is easy to fabricate and scale-up.

  2. Engineering Schottky Contacts in Open-Air Fabricated Heterojunction Solar Cells to Enable High Performance and Ohmic Charge Transport

    PubMed Central

    2014-01-01

    The efficiencies of open-air processed Cu2O/Zn1–xMgxO heterojunction solar cells are doubled by reducing the effect of the Schottky barrier between Zn1–xMgxO and the indium tin oxide (ITO) top contact. By depositing Zn1–xMgxO with a long band-tail, charge flows through the Zn1–xMgxO/ITO Schottky barrier without rectification by hopping between the sub-bandgap states. High current densities are obtained by controlling the Zn1–xMgxO thickness to ensure that the Schottky barrier is spatially removed from the p–n junction, allowing the full built-in potential to form, in addition to taking advantage of the increased electrical conductivity of the Zn1–xMgxO films with increasing thickness. This work therefore shows that the Zn1–xMgxO window layer sub-bandgap state density and thickness are critical parameters that can be engineered to minimize the effect of Schottky barriers on device performance. More generally, these findings show how to improve the performance of other photovoltaic system reliant on transparent top contacts, e.g., CZTS and CIGS. PMID:25418326

  3. Sickle cell trait as a limiting factor for high-level performance in a semi-marathon.

    PubMed

    Le Gallais, D; Prefaut, C; Mercier, J; Bile, A; Bogui, P; Lonsdorfer, J

    1994-10-01

    Of 1506 black males participating in the first Abidjan semi-marathon, 123 subjects with sickle cell trait (SCT) were detected, i.e., 8.7%. Twenty-nine of these subjects with hemoglobin S (HbS) were ranked among the first 332 participants to finish the race, a percentage of 8.2. These percentages did not significantly differ from the prevalence of SCT observed in the general Ivory Coast population (12.0%). Only one subject with SCT was found among the 22 internationally-ranked athletes. The concentration of HbS found in this athlete (37.7%), his mean globular volume (87 fl), and his hemoglobin concentration (13.8 g/100 ml) suggest the coexistence of alpha-thalassemia with SCT. These results indicate that the percentage of SCT individuals participating in a semi-marathon is equal to the prevalence of SCT found in the local population. Furthermore, the general ranking of SCT individuals is comparable to that of non-SCT individuals. Nevertheless, at the level of internationally-ranked performance, no subject with SCT only, was ranked; the one ranked subject with SCT presented an associated alpha thalassemia. We thus hypothesize that SCT may be a limiting factor for high level performance in a semi-marathon and alpha-thalassemia, an enhancing factor for subjects with SCT to succeed in long distance races.

  4. Nanostructured macroporous bioanode based on polyaniline-modified natural loofah sponge for high-performance microbial fuel cells.

    PubMed

    Yuan, Yong; Zhou, Shungui; Liu, Yi; Tang, Jiahuan

    2013-12-17

    Microbial fuel cells (MFCs) are a promising technology to recover electrical energy from different types of waste. However, the power density of MFCs for practical applications is limited by the anode performance, mainly resulting from low bacterial loading capacity and low extracellular electron transfer (EET) efficiency. In this study, an open three-dimensional (3D) structured electrode was fabricated using a natural loofah sponge as the precursor material. The loofah sponge was directly converted into a continuous 3D macroporous carbon material via a simple carbonization procedure. The loofah sponge carbon (LSC) was decorated with nitrogen-enriched carbon nanoparticles by cocarbonizing polyaniline-hybridized loofah sponges to improve their microscopic structures. The macroscale porous structure of the LSCs greatly increased the bacterial loading capacity. The microscale coating of carbon nanoparticles favored EET due to the enhanced interaction between the bacteria and the anode. By using a single-chamber MFC equipped with the fabricated anode, a power density of 1090 ± 72 mW m(-2) was achieved, which is much greater than that obtained by similarly sized traditional 3D anodes. This study introduces a promising method for the fabrication of high-performance anodes from low-cost, sustainable natural materials.

  5. 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.

  6. 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.

  7. High Performance Work Systems and Firm Performance.

    ERIC Educational Resources Information Center

    Kling, Jeffrey

    1995-01-01

    A review of 17 studies of high-performance work systems concludes that benefits of employee involvement, skill training, and other high-performance work practices tend to be greater when new methods are adopted as part of a consistent whole. (Author)

  8. Enhancing the grain size of organic halide perovskites by sulfonate-carbon nanotube incorporation in high performance perovskite solar cells.

    PubMed

    Zhang, Yong; Tan, Licheng; Fu, Qingxia; Chen, Lie; Ji, Ting; Hu, Xiaotian; Chen, Yiwang

    2016-04-28

    The grain size of perovskites was enhanced and the grain boundary was filled with sulfonate carbon nanotubes (s-CNTs) during the CH3NH3PbI3 perovskite precursor solution spin-coating process with the incorporation of s-CNTs. The performance of s-CNT incorporated perovskite solar cells remarkably increased from 10.3% to 15.1% (best) compared with pristine CNT incorporated perovskite solar cells.

  9. High performance anode-supported tubular solid oxide fuel cells fabricated by a novel slurry-casting method

    PubMed Central

    Duan, Nan-Qi; Yan, Dong; Chi, Bo; Pu, Jian; Jian, Li

    2015-01-01

    Tubular solid oxide fuel cells were fabricated and evaluated for their microstructure and electrochemical performance. The tubular substrate was prepared by casting NiO-Y2O3 stabilized ZrO2 (YSZ) slurry on the inner wall of a plastic mold (tube). The wall thickness and uniformity were controlled by slurry viscosity and rotation speed of the tube. The cells consisted of Ni-YSZ functional anode, YSZ electrolyte and (La0.8Sr0.2)0.95MnO3-δ (LSM)-YSZ cathode prepared in sequence on the substrate by dip-coating and sintering. Their dimension was 50 mm in length, 0.8 mm in thickness and 10.5 mm in outside diameter. The peak power density of the cell at temperatures between 650 and 850°C was in the range from 85 to 522 mW cm−2 and was greatly enhanced to the range from 308 to 1220 mW cm−2 by impregnating PdO into LSM-YSZ cathode. During a cell testing at 0.7 A cm−2 and 750°C for 282 h, the impregnated PdO particles grew by coalescence, which increased the cathode polarization resistance and so that decreased the cell performance. According to the degradation tendency, the cell performance will be stabilized in a longer run. PMID:25640168

  10. High performance anode-supported tubular solid oxide fuel cells fabricated by a novel slurry-casting method

    NASA Astrophysics Data System (ADS)

    Duan, Nan-Qi; Yan, Dong; Chi, Bo; Pu, Jian; Jian, Li

    2015-02-01

    Tubular solid oxide fuel cells were fabricated and evaluated for their microstructure and electrochemical performance. The tubular substrate was prepared by casting NiO-Y2O3 stabilized ZrO2 (YSZ) slurry on the inner wall of a plastic mold (tube). The wall thickness and uniformity were controlled by slurry viscosity and rotation speed of the tube. The cells consisted of Ni-YSZ functional anode, YSZ electrolyte and (La0.8Sr0.2)0.95MnO3-δ (LSM)-YSZ cathode prepared in sequence on the substrate by dip-coating and sintering. Their dimension was 50 mm in length, 0.8 mm in thickness and 10.5 mm in outside diameter. The peak power density of the cell at temperatures between 650 and 850°C was in the range from 85 to 522 mW cm-2 and was greatly enhanced to the range from 308 to 1220 mW cm-2 by impregnating PdO into LSM-YSZ cathode. During a cell testing at 0.7 A cm-2 and 750°C for 282 h, the impregnated PdO particles grew by coalescence, which increased the cathode polarization resistance and so that decreased the cell performance. According to the degradation tendency, the cell performance will be stabilized in a longer run.

  11. High performance anode-supported tubular solid oxide fuel cells fabricated by a novel slurry-casting method.

    PubMed

    Duan, Nan-Qi; Yan, Dong; Chi, Bo; Pu, Jian; Jian, Li

    2015-02-02

    Tubular solid oxide fuel cells were fabricated and evaluated for their microstructure and electrochemical performance. The tubular substrate was prepared by casting NiO-Y2O3 stabilized ZrO2 (YSZ) slurry on the inner wall of a plastic mold (tube). The wall thickness and uniformity were controlled by slurry viscosity and rotation speed of the tube. The cells consisted of Ni-YSZ functional anode, YSZ electrolyte and (La0.8Sr0.2)0.95MnO(3-δ) (LSM)-YSZ cathode prepared in sequence on the substrate by dip-coating and sintering. Their dimension was 50 mm in length, 0.8 mm in thickness and 10.5 mm in outside diameter. The peak power density of the cell at temperatures between 650 and 850°C was in the range from 85 to 522 mW cm(-2) and was greatly enhanced to the range from 308 to 1220 mW cm(-2) by impregnating PdO into LSM-YSZ cathode. During a cell testing at 0.7 A cm(-2) and 750°C for 282 h, the impregnated PdO particles grew by coalescence, which increased the cathode polarization resistance and so that decreased the cell performance. According to the degradation tendency, the cell performance will be stabilized in a longer run.

  12. High performance cermet electrodes

    DOEpatents

    Isenberg, Arnold O.; Zymboly, Gregory E.

    1986-01-01

    Disclosed is a method of increasing the operating cell voltage of a solid oxide electrochemical cell having metal electrode particles in contact with an oxygen-transporting ceramic electrolyte. The metal electrode is heated with the cell, and oxygen is passed through the oxygen-transporting ceramic electrolyte to the surface of the metal electrode particles so that the metal electrode particles are oxidized to form a metal oxide layer between the metal electrode particles and the electrolyte. The metal oxide layer is then reduced to form porous metal between the metal electrode particles and the ceramic electrolyte.

  13. Characterization of local electrochemical doping of high performance conjugated polymer for photovoltaics using scanning droplet cell microscopy.

    PubMed

    Gasiorowski, Jacek; Mardare, Andrei Ionut; Sariciftci, Niyazi Serdar; Hassel, Achim Walter

    2013-12-15

    The electrochemical oxidation of a next generation low bandgap high performance photovoltaic material namely poly[4,8-bis-substituted-benzo[1,2-b:4,5-b0]dithiophene-2,6-diyl-alt-4-substituted-thieno[3,4-b] thiophene-2,6-diyl] (PBDTTT-c) thin film was investigated using a scanning droplet cell microscope. Cyclic voltammetry was used for the basic characterization of the oxidation/doping of PBDTTT-c. Application of the different final potentials during the electrochemical study provides a close look to the oxidation kinetics. The electrical properties of both doped and undoped PBDTTT-c were analyzed in situ by electrochemical impedance spectroscopy giving the possibility to correlate the changes in the doping level with the subsequent changes in the resistance and capacitance. As a result one oxidation peak was found during the cyclic voltammetry and in potentiostatic measurements. From Mott-Schottky analysis a donor concentration of 2.3 × 10(20) cm(-3) and a flat band potential of 1.00 V vs. SHE were found. The oxidation process resulted in an increase of the conductivity by two orders of magnitude reaching a maximum for the oxidized form of 1.4 S cm(-1).

  14. All-nano-TiO2 compact film for high-performance dye-sensitized solar cells.

    PubMed

    Zanoni, Kassio P S; Amaral, Ronaldo C; Murakami Iha, Neyde Y

    2014-07-09

    An innovative all-nano-TiO2 thin film capable of enhancing dye-sensitized solar cell (DSC) photoefficiencies was prepared by a layer-by-layer method beneath the meso-TiO2 film, employing acid and basic nano-TiO2 sols as cations and anions, respectively. TiO2 syntheses were performed under absolute control to lead to appropriate morphological and optical properties to yield high-quality compact films using profilometry, tuning, and scanning electron microscopy. A detailed study by photoelectrochemical parameters, incident photon-to-current efficiency, electron lifetime, and electrochemical impedance spectroscopy demonstrates that the physical contact between FTO and the electrolyte is prevented and the role of the compact film has been elucidated. DSCs with TiO2 bilayers on top of FTO improved the conversion efficiency up to 62%, mainly because of the prevention of FTO/I3(-) charge recombination and an improved contact between FTO and TiO2.

  15. Macroporous graphitic carbon foam decorated with polydopamine as a high-performance anode for microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Jiang, Hongmei; Yang, Lu; Deng, Wenfang; Tan, Yueming; Xie, Qingji

    2017-09-01

    Herein, a macroporous graphitic carbon foam (MGCF) electrode decorated with polydopamine (PDA) is used as a high-performance anode for microbial fuel cell (MFC) applications. The MGCF is facilely prepared by pyrolysis of a powder mixture comprising maltose, nickel nitrate, and ammonia chloride, without using solid porous template. The MGCF is coated with PDA by self-polymerization of dopamine in a basic solution. The MGCF can provide a large surface area for bacterial attachment, and PDA coated on the MGCF electrode can further promote bacterial adhesion resulting from the improved hydrophility, so the MGCF-PDA electrode as an anode in a MFC can show ultrahigh bacterial loading capacity. Moreover, the electrochemical oxidation of flavins at the MGCF-PDA electrode is greatly accelerated, so the extracellular electron transfer mediated by flavins is improved. As a result, the MFC equipped with a MGCF-PDA anode can show a maximum power density of 1735 mW cm-2, which is 6.7 times that of a MFC equipped with a commercial carbon felt anode, indicating a promising anode for MFC applications.

  16. Controlled modification of carbon nanotubes and polyaniline on macroporous graphite felt for high-performance microbial fuel cell anode

    NASA Astrophysics Data System (ADS)

    Cui, Hui-Fang; Du, Lin; Guo, Peng-Bo; Zhu, Bao; Luong, John H. T.

    2015-06-01

    Polyaniline (PANI) was electropolymerized on the surface of macroporous graphite felt (GF) followed by the electrophoretic deposition of carbon nanotubes (CNTs). The as-prepared macroporous material was characterized by scanning electron microscopy, water contact angle goniometry and electrochemical techniques. Upon the modification of PANI, a rough and nano-cilia containing film is coated on the surface of the graphite fibers, transforming the surface from hydrophobic to hydrophilic. The subsequent modification by CNTs increases the effective surface area and electrical conductivity of the resulting material. The power output of a mediator-free dual-chamber microbial fuel cell (MFC) constructed from the GF anode and an exoelectrogen Shewanella putrefaciens increases drastically with the CNT modification. The CNT/PANI/GF MFC attains an output voltage of 342 mV across an external resistor of 1.96 kΩ constant load, and a maximum power density of 257 mW m-2, increased by 343% and 186%, compared to that of the pristine GF MFC and the PANI/GF MFC, respectively. More bacteria are attached on the CNT/PANI/GF anode than on the PANI/GF anode during the working of the MFC. This strategy provides an easy scale-up, simple and controllable method for the preparation of high-performance and low-cost MFC anodes.

  17. Binder-free graphene and manganese oxide coated carbon felt anode for high-performance microbial fuel cell.

    PubMed

    Zhang, Changyong; Liang, Peng; Yang, Xufei; Jiang, Yong; Bian, Yanhong; Chen, Chengmeng; Zhang, Xiaoyuan; Huang, Xia

    2016-07-15

    A novel anode was developed by coating reduced graphene oxide (rGO) and manganese oxide (MnO2) composite on the carbon felt (CF) surface. With a large surface area and excellent electrical conductivity, this binder-free anode was found to effectively enhance the enrichment and growth of electrochemically active bacteria and facilitate the extracellular electron transfer from the bacteria to the anode. A microbial fuel cell (MFC) equipped with the rGO/MnO2/CF anode delivered a maximum power density of 2065mWm(-2), 154% higher than that with a bare CF anode. The internal resistance of the MFC with this novel anode was 79Ω, 66% lower than the regular one's (234Ω). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses affirmed that the rGO/MnO2 composite significantly increased the anodic reaction rates and facilitated the electron transfer from the bacteria to the anode. The findings from this study suggest that the rGO/MnO2/CF anode, fabricated via a simple dip-coating and electro-deposition process, could be a promising anode material for high-performance MFC applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Investigation on the Performance of CIGS/TiO2 Heterojunction Using SCAPS Software for Highly Efficient Solar Cells

    NASA Astrophysics Data System (ADS)

    Chihi, A.; Boujmil, M. F.; Bessais, B.

    2017-08-01

    In this study, Cu (In, Ga) Se2 (CIGS) material with the non-toxic titanium dioxide TiO2 as an n-type buffer layer and indium tin oxide as the window layer are numerically simulated using a solar cell capacitance simulation software package. This numerical analysis has been carried out with the aim of boosting the performances of CIGS/TiO2 solar cells by tuning the defect density and band gap energy of the ordered vacancy compound (OVC) layer and by using a Back-electron reflector (EBR) layer, namely Al2O3. Solar cell performance is investigated as a function of absorber thickness. It is found that there exists an optimal thickness. The effect of OVC compounds on the performance of the device structure are discussed leading to an optimal band gap energy and defect density of about 1.17 eV and 4.97 × 1013 cm-3, respectively. The matching solar cell conversion efficiency reached a maximum value of 12.38% by introducing the OVC layer. It is also shown that, in spite of a decrease in thickness, the external quantum efficiency (EQE) of ultrathin CIGS solar cells can be enhanced owing to the employment of EBR. The significant improvement of EQE, mainly in the near-infrared part of the solar spectrum, can be ascribed to the low parasitic absorption loss in the ultrathin CIGS layer (˜570 nm).

  19. Quantification of miltefosine in peripheral blood mononuclear cells by high-performance liquid chromatography-tandem mass spectrometry

    PubMed Central

    Kip, A.E.; Rosing, H.; Hillebrand, M.J.X.; Castro, M.M.; Gomez, M.A.; Schellens, J.H.M.; Beijnen, J.H.; Dorlo, T.P.C.

    2015-01-01

    Phagocytes, the physiological compartment in which Leishmania parasites reside, are the main site of action of the drug miltefosine, but the intracellular pharmacokinetics of miltefosine remain unexplored. We developed a bioanalytical method to quantify miltefosine in human peripheral blood mononuclear cells (PBMCs), expanding from an existing high performance liquid chromatography-tandem mass spectrometry method for the quantification of miltefosine in plasma. The method introduced deuterated miltefosine as an internal standard. Miltefosine was extracted from PBMC pellets by addition of 62.5% methanol. Supernatant was collected, evaporated and reconstituted in plasma. Chromatographic separation was performed on a reversed phase C18 column and detection with a triple-quadrupole mass spectrometer. Miltefosine was quantified using plasma calibration standards ranging from 4 to 1000 ng/mL. This method was validated with respect to its PBMC matrix effect, selectivity, recovery and stability. No matrix effect could be observed from the PBMC content (ranging from 0.17 to 26.3 × 106 PBMCs) reconstituted in plasma, as quality control samples were within 3.0% of the nominal concentration (precision less than 7.7%). At the lower limit of quantitation of 4 ng/mL plasma, corresponding to 0.12 ng/106 PBMCs in a typical clinical sample, measured concentrations were within 8.6% of the nominal value. Recovery showed to be reproducible as adding additional pre-treatment steps did not increase the recovery with more than 9%. This method was successfully applied to measure intracellular miltefosine concentrations in PBMC samples from six cutaneous leishmaniasis patients up to one month post-treatment. PMID:26160472

  20. High-Performance Integrated Perovskite and Organic Solar Cells with Enhanced Fill Factors and Near-Infrared Harvesting.

    PubMed

    Kim, Junghwan; Kim, Geunjin; Back, Hyungcheol; Kong, Jaemin; Hwang, In-Wook; Kim, Tae Kyun; Kwon, Sooncheol; Lee, Jong-Hoon; Lee, Jinho; Yu, Kilho; Lee, Chang-Lyoul; Kang, Hongkyu; Lee, Kwanghee

    2016-04-01

    Highly efficient P-I-N type perovskite/bulk-heterojunction (BHJ) integrated solar cells (ISCs) with enhanced fill factor (FF) (≈80%) and high near-infrared harvesting (>30%) are demonstrated by optimizing the BHJ morphology with a novel n-type polymer, N2200, and a new solvent-processing additive. This work proves the feasibility of highly efficient ISCs with panchromatic absorption as a new photovoltaic architecture and provides important design rules for optimizing ISCs.

  1. Investigation of electrolyte leaching in the performance degradation of phosphoric acid-doped polybenzimidazole membrane-based high temperature fuel cells

    NASA Astrophysics Data System (ADS)

    Jeong, Yeon Hun; Oh, Kyeongmin; Ahn, Sungha; Kim, Na Young; Byeon, Ayeong; Park, Hee-Young; Lee, So Young; Park, Hyun S.; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Ju, Hyunchul; Kim, Jin Young

    2017-09-01

    Precise monitoring of electrolyte leaching in high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) devices during lifetime tests is helpful in making a diagnosis of their quality changes and analyzing their electrochemical performance degradation. Here, we investigate electrolyte leaching in the performance degradation of phosphoric acid (PA)-doped polybenzimidazole (PBI) membrane-based HT-PEMFCs. We first perform quantitative analyses to measure PA leakage during cell operation by spectrophotometric means, and a higher PA leakage rate is detected when the current density is elevated in the cell. Second, long-term degradation tests under various current densities of the cells and electrochemical impedance spectroscopy (EIS) analysis are performed to examine the influence of PA loss on the membrane and electrodes during cell performance degradation. The combined results indicate that PA leakage affect cell performance durability, mostly due to an increase in charge transfer resistance and a decrease in the electrochemical surface area (ECSA) of the electrodes. Additionally, a three-dimensional (3-D) HT-PEMFC model is applied to a real-scale experimental cell, and is successfully validated against the polarization curves measured during various long-term experiments. The simulation results highlight that the PA loss from the cathode catalyst layer (CL) is a significant contributor to overall performance degradation.

  2. High-performance Fuel Cell with Stretched Catalyst-Coated Membrane: One-step Formation of Cracked Electrode

    NASA Astrophysics Data System (ADS)

    Kim, Sang Moon; Ahn, Chi-Yeong; Cho, Yong-Hun; Kim, Sungjun; Hwang, Wonchan; Jang, Segeun; Shin, Sungsoo; Lee, Gunhee; Sung, Yung-Eun; Choi, Mansoo

    2016-05-01

    We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance.

  3. High-performance Fuel Cell with Stretched Catalyst-Coated Membrane: One-step Formation of Cracked Electrode

    PubMed Central

    Kim, Sang Moon; Ahn, Chi-Yeong; Cho, Yong-Hun; Kim, Sungjun; Hwang, Wonchan; Jang, Segeun; Shin, Sungsoo; Lee, Gunhee; Sung, Yung-Eun; Choi, Mansoo

    2016-01-01

    We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance. PMID:27210793

  4. High-performance Fuel Cell with Stretched Catalyst-Coated Membrane: One-step Formation of Cracked Electrode.

    PubMed

    Kim, Sang Moon; Ahn, Chi-Yeong; Cho, Yong-Hun; Kim, Sungjun; Hwang, Wonchan; Jang, Segeun; Shin, Sungsoo; Lee, Gunhee; Sung, Yung-Eun; Choi, Mansoo

    2016-05-23

    We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance.

  5. Commoditization of High Performance Storage

    SciTech Connect

    Studham, Scott S.

    2004-04-01

    The commoditization of high performance computers started in the late 80s with the attack of the killer micros. Previously, high performance computers were exotic vector systems that could only be afforded by an illustrious few. Now everyone has a supercomputer composed of clusters of commodity processors. A similar commoditization of high performance storage has begun. Commodity disks are being used for high performance storage, enabling a paradigm change in storage and significantly changing the price point of high volume storage.

  6. Effect of bottom clearance on performance of airlift bioreactor in high-density culture of Panax notoginseng cells.

    PubMed

    Hu, W; Zhong, J

    2001-01-01

    A fed-batch cultivation of Panax notoginseng cells in a concentric-tube airlift reactor was performed to study the effects of bottom clearance on cell growth and the production of ginseng saponin and polysaccharide. At a bottom clearance of 4.0 cm, the highest cell density of 29.1+/-1.6 g/l by dry weight was obtained, and the accumulation of saponin and polysaccharide also reached a maximum, i.e., 2.39+/-0.43 and 2.73+/-0.40 g/l, respectively. Cell growth and metabolite production were limited at a small (2.5 cm) or large (5.0 cm) bottom clearance. By analyzing the time constants of mixing, mass transfer and oxygen consumption, bulk gas-liquid oxygen transfer was found to be responsible for the growth limitation at a small bottom clearance (2.5 cm). The decrease in cell density at a large bottom clearance (5.0 cm) was related to cell sedimentation at the reactor bottom. This work is beneficial for the scale-up and efficient operation of the airlift reactor in cell cultures.

  7. TiO2 derived by titanate route from electrospun nanostructures for high-performance dye-sensitized solar cells.

    PubMed

    Nair, A Sreekumaran; Zhu, Peining; Babu, V Jagadeesh; Yang, Shengyuan; Krishnamoorthy, Thirumal; Murugan, Rajendiran; Peng, Shengjie; Ramakrishna, Seeram

    2012-04-17

    We report the use of highly porous, dense, and anisotropic TiO(2) derived from electrospun TiO(2)-SiO(2) nanostructures through titanate route in dye-sensitized solar cells. The titanate-derived TiO(2) of high surface areas exhibited superior photovoltaic parameters (efficiency > 7%) in comparison to the respective electrospun TiO(2) nanomaterials and commercially available P-25.

  8. Passivated Tunneling Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells: Preprint

    SciTech Connect

    Stradins, P.; Essig, S.; Nemeth, W.; Lee, B. G.; Young, D.; Norman, A.; Liu, Y.; Luo, J.-W.; Warren, E.; Dameron, A.; LaSalvia, V.; Page, M.; Rohatgi, A.; Upadhyaya, A.; Rounsaville, B.; Ok, Y.-W.; Glunz, S.; Benick, J.; Feldmann, F.; Hermle, M.

    2014-12-01

    We present a case that passivated contacts based on a thin tunneling oxide layer, combined with a transport layer with properly selected work function and band offsets, can lead to high efficiency c-Si solar cells. Passivated contacts contribute to cell efficiency as well as design flexibility, process robustness, and a simplified process flow. Material choices for the transport layer are examined, including transparent n-type oxides and n+-doped poly-Si. SiO2/n+-poly-Si full-area, induced-junction back surface field contacts to n-FZ and n-Cz Si are incorporated into high efficiency cells with deep, passivated boron emitters.

  9. Lead Iodide Thin Film Crystallization Control for High-Performance and Stable Solution-Processed Perovskite Solar Cells.

    PubMed

    Yang, Lijun; Wang, Jingchuan; Leung, Wallace Woon-Fong

    2015-07-15

    PbI2 thin film crystallization control is a prerequisite of high-quality perovskite thin film for sequentially solution-processed perovskite solar cells. An efficient and simple method has been developed by adding HCl to improve perovskite thin film quality, and an efficiency of 15.2% is obtained. This approach improves coverage, uniformity, and stability of pervoskite thin film.

  10. High performance collectors

    NASA Astrophysics Data System (ADS)

    Ogawa, H.; Hozumi, S.; Mitsumata, T.; Yoshino, K.; Aso, S.; Ebisu, K.

    1983-04-01

    Materials and structures used for flat plate solar collectors and evacuated tubular collectors were examined relative to their overall performance to project effectiveness for building heating and cooling and the feasibility of use for generating industrial process heat. Thermal efficiencies were calculated for black paint single glazed, selective surface single glazed, and selective surface double glazed flat plate collectors. The efficiencies of a single tube and central tube accompanied by two side tube collectors were also studied. Techniques for extending the lifetimes of the collectors were defined. The selective surface collectors proved to have a performance superior to other collectors in terms of the average annual energy delivered. Addition of a black chrome-coated fin system to the evacuated collectors produced significant collection efficiency increases.

  11. High Performance Arcjet Engines

    NASA Technical Reports Server (NTRS)

    Kennel, Elliot B.; Ivanov, Alexey Nikolayevich; Nikolayev, Yuri Vyacheslavovich

    1994-01-01

    This effort sought to exploit advanced single crystal tungsten-tantalum alloy material for fabrication of a high strength, high temperature arcjet anode. The use of this material is expected to result in improved strength, temperature resistance, and lifetime compared to state of the art polycrystalline alloys. In addition, the use of high electrical and thermal conductivity carbon-carbon composites was considered, and is believed to be a feasible approach. Highly conductive carbon-carbon composite anode capability represents enabling technology for rotating-arc designs derived from the Russian Scientific Research Institute of Thermal Processes (NIITP) because of high heat fluxes at the anode surface. However, for US designs the anode heat flux is much smaller, and thus the benefits are not as great as in the case of NIITP-derived designs. Still, it does appear that the tensile properties of carbon-carbon can be even better than those of single crystal tungsten alloys, especially when nearly-single-crystal fibers such as vapor grown carbon fiber (VGCF) are used. Composites fabricated from such materials must be coated with a refractory carbide coating in order to ensure compatibility with high temperature hydrogen. Fabrication of tungsten alloy single crystals in the sizes required for fabrication of an arcjet anode has been shown to be feasible. Test data indicate that the material can be expected to be at least the equal of W-Re-HfC polycrystalline alloy in terms of its tensile properties, and possibly superior. We are also informed by our colleagues at Scientific Production Association Luch (NP0 Luch) that it is possible to use Russian technology to fabricate polycrystalline W-Re-HfC or other high strength alloys if desired. This is important because existing engines must rely on previously accumulated stocks of these materials, and a fabrication capability for future requirements is not assured.

  12. High Performance Organic Semiconductors

    DTIC Science & Technology

    2012-07-31

    the polymers in o-DCB. Grazing incidence X-ray diffraction (GIXD) studies performed on oADT-dTDPP thin films shows distinct out-of- plane (h00...have helped to promote interchain interactions and the formation of lamellar order. In- plane diffraction intensity profile along qxy shows multiple...perpendicular to the substrate, a motif that may give rise to better in- plane charge transport properties than previous less-ordered ADT-containing polymer

  13. High Performance Hollow Projectiles

    DTIC Science & Technology

    Development of hollow projectiles was first advocated to achieve ’silent’ (low pressure signal) projectiles having higher performance. Although the...present effort concentrates on small arms (specifically 7.62 mm), the confirmed fundamental theory applies to all sizes of hollow projectiles. The...report can thus serve as a basis for (1) evaluating specific hollow projectile developments and (2) formulating programs to develop a wide spectrum of

  14. Dataset demonstrating the modeling of a high performance Cu(In,Ga)Se2 absorber based thin film photovoltaic cell.

    PubMed

    Asaduzzaman, Md; Bahar, Ali Newaz; Bhuiyan, Mohammad Maksudur Rahman

    2017-04-01

    The physical data of the semiconductor materials used in the design of a CIGS absorber based thin film photovoltaic cell have been presented in this data article. Besides, the values of the contact parameter and operating conditions of the cell have been reported. Furthermore, by conducting the simulation with data corresponding to the device structure: soda-lime glass (SLG) substrate/Mo back-contact/CIGS absorber/CdS buffer/intrinsic ZnO/Al-doped ZnO window/Al-grid front-contact, the solar cell performance parameters such as open circuit voltage [Formula: see text], short circuit current density [Formula: see text], fill factor [Formula: see text], efficiency [Formula: see text], and collection efficiency [Formula: see text] have been analyzed.

  15. High performance silicon-organic hybrid solar cells via improving conductivity of PEDOT:PSS with reduced graphene oxide

    NASA Astrophysics Data System (ADS)

    Jiang, Xinyu; Wang, Zilei; Han, Wenhui; Liu, Qiming; Lu, Shuqi; Wen, Yuxiang; Hou, Juan; Huang, Fei; Peng, Shanglong; He, Deyan; Cao, Guozhong

    2017-06-01

    The optical and electrical properties of PEDOT:PSS organic layer play a very important role in determining the power conversion efficiency (PCE) of Si-organic hybrid solar cells (HSCs). In the present study, properties of PEDOT:PSS thin films with reduced graphene oxide (rGO) and their impacts on the performances of the resultant Si-organic HSCs have been systematically investigated. The electrical conductivity of PEDOT:PSS improved 35% when rGO was added to PEDOT:PSS, and the fabricated HSCs with 2 mg/ml rGO addition yielded an PCE of 11.95% with a Jsc of 31.94 mAcm-2, a Voc of 579 mV and a FF of 0.648. However, excess rGO would deteriorate the solar cells performances and it might create additional defects and prevent carriers being collected. The Raman spectroscopy, sheet resistance and EQE analyses with rGO suggested that the interaction between the conductive rGO flakes and the aromatic PEDOT most probably not only provide additional charge transport pathways in hole transport layer to improve carrier mobility leading to a higher carrier collection efficiency, but also suppress the electron recombination at the junction interface. In addition, the rGO serve as an antireflection coating to reduce the reflectance of PEDOT:PSS thin film leading to further enhanced performances of solar cells.

  16. High Performance Magnets

    DTIC Science & Technology

    2000-03-29

    Our efforts in this project were focused on three different materials, namely; interstitial Sm-Fe carbides and nitrides, high energy product Nd2Fe14B ...magnets with MgO addition, and nanocomposite Nd2Fe14B /alpha-Fe consisting of a fine mixture of hard and soft phases. In the Sm-Fe carbides and

  17. High performance solid oxide fuel cells based on tri-layer yttria-stabilized zirconia by low temperature sintering process

    NASA Astrophysics Data System (ADS)

    Liu, Ze; Zheng, Zi-wei; Han, Min-fang; Liu, Mei-lin

    Performance of solid oxide fuel cells (SOFCs) depends critically on the composition and microstructure of the electrodes. It is fabricated a dense yttria-stabilized zirconia (YSZ) electrolyte layer sandwiched between two porous YSZ layers at low temperature. The advantages of this structure include excellent structural stability and unique flexibility for evaluation of new electrode materials for SOFC applications, which would be difficult or impossible to be evaluated using conventional cell fabrication techniques because of incompatibility with YSZ under processing conditions. The porosity of porous YSZ increases from 65.8% to 68.6% as the firing temperature decreased from 1350 to 1200 °C. The open cell voltages of the cells based on the tri-layers of YSZ, co-fired using a two-step sintering at 1200 °C, are above 1.0 V at 700-800 °C, and the peak power densities of cells infiltrated LSCF and Pd-SDC electrodes are about 525, 733, and 935 mW cm -2 at 700, 750, and 800 °C, respectively.

  18. Long-life high performance fuel cell program. Interim Report, 28 May 1981-31 October 1984

    SciTech Connect

    Martin, R.E.

    1985-02-01

    A multihundred kilowatt Regenerative Fuel Cell for use in a space station is envisioned. Three 0.508 sq ft (471.9 cm) active area multicell stacks were assembled and endurance tested. The long term performance stability of the platinum on carbon catalyst configuration suitability of the lightweight graphite electrolyte reservoir plate, the stability of the free standing butyl bonded potassium titanate matrix structure, and the long life potential of a hybrid polysulfone cell edge frame construction were demonstrated. A 18,000 hour demonstration test of multicell stack to a continuous cyclical load profile was conducted. A total of 12,000 cycles was completed, confirming the ability of the alkaline fuel cell to operate to a load profile simulating Regenerative Fuel Cell operation. An orbiter production hydrogen recirculation pump employed in support of the cyclical load profile test completed 13,000 hours of maintenance free operation. Laboratory endurance tests demonstrated the suitability of the butyl bonded potassium matrix, perforated nickel foil electrode substrates, and carbon ribbed substrate anode for use in the alkaline fuel cell. Corrosion testing of materials at 250 F (121.1 C) in 42% wgt. potassium identified ceria, zirconia, strontium titanate, strontium zirconate and lithium cobaltate as candidate matrix materials.

  19. Inks for Ink Jet Printed Contacts for High Performance Silicon Solar Cells: Cooperative Research and Development Final Report, CRADA No. CRD-06-199

    SciTech Connect

    Ginley, D.

    2013-01-01

    The work under the proposed CRADA will be a joint effort by BP Solar and NREL to develop new types of high performance inks for high quality contacts to silicon solar cells. NREL will develop inks that have electronic properties that will allow the formation of high quality ohmic contacts to n- and p-type crystalline silicon, and BP Solar will evaluate these contacts in test contact structures.

  20. High Performance YBCO Films

    DTIC Science & Technology

    1992-07-01

    growing high quality MgO films on SrF2 substrates is the oxygen partial pressure during the growth. The x-ray data presented in Fig. 13 indicates a...fluo-ide and quartz substrates. The best result with two buffer layers (MgO and YSZ) on SrF2 was an onset temperature (Tc) of 82K and a transition...With a YSZ buffer an onset temperature of 85K and a transition width of 5K was achieved. Recent success was demonstrated by Neocera ( under a NASA

  1. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-10-01

    Over 30 years ago U.S. industry introduced the world`s highest temperature (1200{degrees}F at 5000 psig) and most efficient power plant, the Eddystone coal-burning steam plant. The highest alloy material used in the plant was 316 stainless steel. Problems during the first few years of operation caused a reduction in operating temperature to 1100{degrees}F which has generally become the highest temperature used in plants around the world. Leadership in high temperature steam has moved to Japan and Europe over the last 30 years.

  2. High Voltage SPT Performance

    NASA Technical Reports Server (NTRS)

    Manzella, David; Jacobson, David; Jankovsky, Robert

    2001-01-01

    A 2.3 kW stationary plasma thruster designed to operate at high voltage was tested at discharge voltages between 300 and 1250 V. Discharge specific impulses between 1600 and 3700 sec were demonstrated with thrust between 40 and 145 mN. Test data indicated that discharge voltage can be optimized for maximum discharge efficiency. The optimum discharge voltage was between 500 and 700 V for the various anode mass flow rates considered. The effect of operating voltage on optimal magnet field strength was investigated. The effect of cathode flow rate on thruster efficiency was considered for an 800 V discharge.

  3. Synthesis and distribution of glycosaminoglycans in human leukemic B- and T-cells and monocytes studied using specific enzymic treatments and high-performance liquid chromatography.

    PubMed

    Makatsori, E; Karamanos, N K; Papadogiannakis, N; Hjerpe, A; Anastassiou, E D; Tsegenidis, T

    2001-10-01

    Identification of glycosaminoglycans (GAGs) synthesized by three human leukaemic cell lines-Jurkat (T-cell leukaemia), Daudi (Burkitt's lymphoma, B-cell leukaemia) and THP-1 (acute monocytic leukemia)-and normal peripheral blood mononuclear cells (PBMC) and their distribution among cell membrane and culture medium were studied. GAGs were isolated using ion-exchange chromatography on DEAE-Sephacel and their composition and fine chemical structure were studied using high-performance liquid chromatography with radiochemical detection. All cell lines synthesize chondroitin sulphate (CS) and heparan sulphate (HS) in both cell membrane and culture medium. No hyaluronan was detected using treatment with specific lyases and highly sensitive HPLC methodology. CS is the major secreted GAG in all cell lines tested and the major cell retained GAG in Jurkat and Daudi. HS is the major GAG in the cell membrane of THP-1. The amounts of distinct GAGs synthesized by all cancer cell lines differ from those produced by normal PBML indicating a major role of GAGs in malignant transformation of human lymphocytes and monocytes. Copyright 2001 John Wiley & Sons, Ltd.

  4. Tough high performance composite matrix

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor); Johnston, Norman J. (Inventor)

    1994-01-01

    This invention is a semi-interpentrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide. Provided is an improved high temperature matrix resin which is capable of performing in the 200 to 300 C range. This resin has significantly improved toughness and microcracking resistance, excellent processability, mechanical performance, and moisture and solvent resistances.

  5. Screening anti-tumor compounds from Ligusticum wallichii using cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry.

    PubMed

    Zhang, Tao; Ding, Yuanyuan; An, Hongli; Feng, Liuxin; Wang, Sicen

    2015-07-14

    Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry was developed. Tyrosine 367 Cysteine-HEK293 cells were used as cell membrane stationary phase. Specificity and reproducibility of the cell membrane chromatography was evaluated using 1-tert-butyl-3-{2-[4-(diethylamino)butylamino]-6-(3,5-dimethoxyphenyl)pyrido[2,3-d]pyrimidin-7-yl}urea, Nimodipine and dexamethasone acetate. Then, anti-tumor components acting on Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 were screened and identified from extracts of Ligusticum wallichii. Components from the extract were retained on the cell membrane chromatographic column. The retained fraction was directly eluted into high-performance liquid chromatography with mass spectrometry system for separation and identification. Finally, Levistolide A was identified as an active component from Ligusticum wallichii extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan colorimetric assay revealed that Levistolide A inhibits proliferation of overexpressing the mutated receptor cells with dose-dependent manner. Phosphorylation of fibroblast growth factor receptor 4 was also decrease under Levistolide A treatment. Flex dock simulation verified that Levistolide A could bind with the tyrosine kinase domain of fibroblast growth factor receptor 4. Therefore, Levistolide A screened by the cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry can arrest cell growth. In conclusion, the two-dimensional high-performance liquid chromatography method can screen and identify potential anti-tumor ingredients which specifically act on the tyrosine kinase domain of the mutated fibroblast growth factor receptor 4. This article is protected by copyright. All rights reserved.

  6. Modeling and experimental performance of an intermediate temperature reversible solid oxide cell for high-efficiency, distributed-scale electrical energy storage

    NASA Astrophysics Data System (ADS)

    Wendel, Christopher H.; Gao, Zhan; Barnett, Scott A.; Braun, Robert J.

    2015-06-01

    Electrical energy storage is expected to be a critical component of the future world energy system, performing load-leveling operations to enable increased penetration of renewable and distributed generation. Reversible solid oxide cells, operating sequentially between power-producing fuel cell mode and fuel-producing electrolysis mode, have the capability to provide highly efficient, scalable electricity storage. However, challenges ranging from cell performance and durability to system integration must be addressed before widespread adoption. One central challenge of the system design is establishing effective thermal management in the two distinct operating modes. This work leverages an operating strategy to use carbonaceous reactant species and operate at intermediate stack temperature (650 °C) to promote exothermic fuel-synthesis reactions that thermally self-sustain the electrolysis process. We present performance of a doped lanthanum-gallate (LSGM) electrolyte solid oxide cell that shows high efficiency in both operating modes at 650 °C. A physically based electrochemical model is calibrated to represent the cell performance and used to simulate roundtrip operation for conditions unique to these reversible systems. Design decisions related to system operation are evaluated using the cell model including current density, fuel and oxidant reactant compositions, and flow configuration. The analysis reveals tradeoffs between electrical efficiency, thermal management, energy density, and durability.

  7. Effects of cell positive cans and separators on the performance of high-voltage Li-ion batteries

    SciTech Connect

    Chen, Xilin; Xu, Wu; Xiao, Jie; Engelhard, Mark H.; Ding, Fei; Mei, Donghai; Hu, Dehong; Zhang, Jian; Zhang, Jiguang

    2012-09-01

    The effects of different cell cans and separators on the first-cycle Coulombic efficiency and long-term cycling stability of high voltage spinel cathode were investigated systematically. Compared to stainless steel (SS) positive-cans, aluminum (Al)-clad SS-316 positive-cans have a much better resistance to oxidation at high voltages thus improving the initial Coulombic efficiency of the batteries by more than 13%. Among the five separators studied in this work, polyethylene (PE) separator shows the best electrochemical stability. The cells using LiCr0.05Ni0.45Mn1.5O4 as cathode, Al-clad positive-can, and PE separator exhibit the first-cycle Columbic efficiency of about 90% and a capacity fading of only 0.01% per cycle.

  8. High-Performance Flexible Perovskite Solar Cells by Using a Combination of Ultrasonic Spray-Coating and Low Thermal Budget Photonic Curing

    SciTech Connect

    Sanjib, Das; Yang, Bin; Gu, Gong; Joshi, Pooran C; Ivanov, Ilia N; Rouleau, Christopher; Aytug, Tolga; Geohegan, David B; Xiao, Kai

    2015-01-01

    Realizing the commercialization of high-performance and robust perovskite solar cells urgently requires the development of economically scalable processing techniques. Here we report a high-throughput ultrasonic spray-coating (USC) process capable of fabricating perovskite film-based solar cells on glass substrates with power conversion efficiency (PCE) as high as 13.04%. Perovskite films with high uniformity, crystallinity, and surface coverage are obtained in a single step. Moreover, we report USC processing on TiOx/ITO-coated polyethylene terephthalate (PET) substrates to realize flexible perovskite solar cells with PCE as high as 8.02% that are robust under mechanical stress. In this case, an optical curing technique was used to achieve a highly-conductive TiOx layer on flexible PET substrates for the first time. The high device performance and reliability obtained by this combination of USC processing with optical curing appears very promising for roll-to-roll manufacturing of high-efficiency, flexible perovskite solar cells.

  9. High performance alloy electroforming

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Winkelman, D. M.

    1989-01-01

    Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718.

  10. Tailorable PC71 BM Isomers: Using the Most Prevalent Electron Acceptor to Obtain High-Performance Polymer Solar Cells.

    PubMed

    Zhan, Xin-Xing; Zhang, Xin; Dai, Si-Min; Li, Shu-Hui; Lu, Xu-Zhai; Deng, Lin-Long; Xie, Su-Yuan; Huang, Rong-Bin; Zheng, Lan-Sun

    2016-12-23

    Despite being widely used as electron acceptor in polymer solar cells, commercially available PC71 BM (phenyl-C71 -butyric acid methyl ester) usually has a "random" composition of mixed regioisomers or stereoisomers. Here PC71 BM has been isolated into three typical isomers, α-, β1 - and β2 -PC71 BM, to establish the isomer-dependent photovoltaic performance on changing the ternary composition of α-, β1 - and β2 -PC71 BM. Mixing the isomers in a ratio of α/β1 /β2 =8:1:1 resulted in the best power conversion efficiency (PCE) of 7.67 % for the polymer solar cells with PTB7:PC71 BM as photoactive layer (PTB7=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

  11. Hydrothermal growth of highly monodispersed TiO2 nanoparticles: Functional properties and dye-sensitized solar cell performance

    NASA Astrophysics Data System (ADS)

    Navaneethan, M.; Nithiananth, S.; Abinaya, R.; Harish, S.; Archana, J.; Sudha, L.; Ponnusamy, S.; Muthamizhchelvan, C.; Ikeda, H.; Hayakawa, Y.

    2017-10-01

    Monodispersed anatase TiO2 nanoparticles were synthesized by hydrothermal method using citric acid as a capping agent. The effect of citric acid and the growth time on the formation of TiO2, functional properties and dye-sensitized solar cell performances were investigated. X-ray diffraction pattern (XRD) and Raman spectroscopy results revealed that the TiO2 nanoparticles possess the anatase phase. Transmission electron microscopy (TEM) measurement revealed the formation of spherical nanoparticles with monodispersity in size and morphology. An average size of 14 nm was obtained for the growth period of 15 h. The maximum efficiency (η) of dye-sensitized solar cell was achieved for TiO2 nanoparticles grown for 15 h as 7.66% which was higher than that of commercial P25 TiO2 (5.23%) and uncapped nanoparticles (3.68%).

  12. High voltage thermal cells

    NASA Astrophysics Data System (ADS)

    Ryan, David M.

    An experiment aimed at a search for new, high-energy cathodes for thermal cells is described. The experiment has begun to reduce the solubility, volatility, and mobility of the cathode materials by preparing and testing massive, relatively immobile cathode molecules. A good candidate for this is the vanadium series, which forms rings, chains, clusters and Keggin compounds. The first three compounds of this genre have been prepared: K3V5O14, Na6V10O28, and K7(Ni4+V13O30). Only the first of these compounds has been tested as a cathode material. The K3V5O14 demonstrated better performance than V2O5, but it is not as good as the FeS2 cells used for benchmarks.

  13. Electrical characterization of fluorinated benzothiadiazole based conjugated copolymer – a promising material for high-performance solar cells

    SciTech Connect

    Toušek, J. Toušková, J.; Chomutová, R.; Remeš, Z.; Čermák, J.; Helgesen, M.; Carlé, J. E.; Krebs, F. C.

    2015-12-15

    Measurements of electrical conductivity, electron work function, carrier mobility of holes and the diffusion length of excitons were performed on samples of conjugated polymers relevant to polymer solar cells. A state of the art fluorinated benzothiadiazole based conjugated copolymer (PBDT{sub THD} − DTBTff) was studied and benchmarked against the reference polymer poly-3-hexylthiophene (P3HT). We employed, respectively, four electrode conductivity measurements, Kelvin probe work function measurements, carrier mobility using charge extraction by linearly increasing voltage (CELIV) measurements and diffusion length determinaton using surface photovoltage measurements.

  14. Architecture engineering of hierarchically porous chitosan/vacuum-stripped graphene scaffold as bioanode for high performance microbial fuel cell.

    PubMed

    He, Ziming; Liu, Jing; Qiao, Yan; Li, Chang Ming; Tan, Timothy Thatt Yang

    2012-09-12

    The bioanode is the defining feature of microbial fuel cell (MFC) technology and often limits its performance. In the current work, we report the engineering of a novel hierarchically porous architecture as an efficient bioanode, consisting of biocompatible chitosan and vacuum-stripped graphene (CHI/VSG). With the hierarchical pores and unique VSG, an optimized bioanode delivered a remarkable maximum power density of 1530 mW m(-2) in a mediator-less MFC, 78 times higher than a carbon cloth anode.

  15. High-performance photoelectrochemical cells based on a binuclear ruthenium catalyst for visible-light-driven water oxidation.

    PubMed

    Zhang, Linlin; Gao, Yan; Ding, Xin; Yu, Ze; Sun, Licheng

    2014-10-01

    Two photoanodes based on a binuclear (2) and a mononuclear ruthenium (3) water oxidation catalysts were assembled in combination with a molecular photosensitizer (1) by using a co-adsorption method. The anodes were used in dye-sensitized photoelectrochemical cells (DS-PECs) for visible-light-driven water splitting. A DS-PEC device using TiO2 (1+2) as working electrode (WE) exhibits better performance than TiO2 (1+3) as WE in light-driven water splitting. Detailed photoelectrochemical studies on these DS-PEC devices are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. High Performance Computing at NASA

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Cooper, D. M. (Technical Monitor)

    1994-01-01

    The speaker will give an overview of high performance computing in the U.S. in general and within NASA in particular, including a description of the recently signed NASA-IBM cooperative agreement. The latest performance figures of various parallel systems on the NAS Parallel Benchmarks will be presented. The speaker was one of the authors of the NAS (National Aerospace Standards) Parallel Benchmarks, which are now widely cited in the industry as a measure of sustained performance on realistic high-end scientific applications. It will be shown that significant progress has been made by the highly parallel supercomputer industry during the past year or so, with several new systems, based on high-performance RISC processors, that now deliver superior performance per dollar compared to conventional supercomputers. Various pitfalls in reporting performance will be discussed. The speaker will then conclude by assessing the general state of the high performance computing field.

  17. Morphology-insensitive Performance Facilitates Transition from Spin-Coating to Roll-to-Roll Coating For High-Performance, Solution-Processed Solar Cells

    NASA Astrophysics Data System (ADS)

    Delongchamp, Dean

    Solution processing via roll-to-roll (R2R) coating promises a low cost, low thermal-budget, sustainable revolution for the production of solar cells. Yet virtually all high efficiency solution processed research cells have been demonstrated by spin-coating, a low-volume deposition process. We present detailed device and morphology studies of an organic photovoltaic (OPV) system deposited by a high volume manufacturing technique, blade-coating, that achieves greater than 9.5 % power conversion efficiency (PCE). The average crystal domain orientation and characteristic phase separation length distribution are markedly different when deposited by blade-coating rather than spin-coating,. This result allows us to determine which aspects of morphology are not relevant to the PCE of this system. Whether the crystallites are ``face on'' or ``edge on'' does not appear to impact the PCE of system, nor does the length scale or ``hierarchical'' nature of the phase length scale. Persistent morphological qualities that may be associated with high PCE in this system are relatively pure phases and relatively strong diffraction. We posit that OPV systems in which the PCE is less sensitive to morphology may also be less sensitive to film thickness, enabling some to maintain high PCE in active layers thicker than greater than ~200 nm. We confirm that blade-coating is a suitable prototyping technique for R2R coating by demonstrating nominally identical morphologies for both piece blade-coating and continuous-web, slot-die coating.

  18. Elucidating the reaction pathways in the synthesis of organolead trihalide perovskite for high-performance solar cells.

    PubMed

    Wang, Baohua; Young Wong, King; Xiao, Xudong; Chen, Tao

    2015-05-28

    The past two years have witnessed unprecedentedly rapid development of organic-inorganic halide perovskite-based solar cells. The solution-processability and high efficiency make this technology extraordinarily attractive. The intensive investigations have accumulated rich experiences in the perovskite fabrication; while the mechanism of the chemical synthesis still remains unresolved. Here, we set up the chemical equation of the synthesis and elucidate the reactions from both thermodynamic and kinetic perspectives. Our study shows that gaseous products thermodynamically favour the reaction, while the activation energy and "collision" probability synergistically determine the reaction rate. These understandings enable us to finely tune the crystal size for high-quality perovskite film, leading to a record fill factor among similar device structures in the literature. This investigation provides a general strategy to explore the mechanism of perovskite synthesis and benefits the fabrication of high-efficiency perovskite photoactive layer.

  19. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  20. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more than two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  1. High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts.

    PubMed

    Bai, Yu; Cao, Yiming; Zhang, Jing; Wang, Mingkui; Li, Renzhi; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael

    2008-08-01

    Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs.

  2. High Performance Fortran: An overview

    SciTech Connect

    Zosel, M.E.

    1992-12-23

    The purpose of this paper is to give an overview of the work of the High Performance Fortran Forum (HPFF). This group of industry, academic, and user representatives has been meeting to define a set of extensions for Fortran dedicated to the special problems posed by a very high performance computers, especially the new generation of parallel computers. The paper describes the HPFF effort and its goals and gives a brief description of the functionality of High Performance Fortran (HPF).

  3. Label-free enumeration of colorectal cancer cells from lymphocytes performed at a high cell-loading density by using interdigitated ring-array microelectrodes.

    PubMed

    Xing, Xiaoxing; Poon, Randy Y C; Wong, Cesar S C; Yobas, Levent

    2014-11-15

    We report the label-free enumeration of human colorectal-carcinoma cells from blood lymphocytes by using interdigitated ring-array microelectrodes; this enumeration was based on the dielectrophoretic selection of cells. Because of the novel design of the device, a continuous flow of cells is uniformly distributed into parallel streams through 300 rings (~40 μm in diameter each) that are integrated into the electrode digits. Using this array, 82% of cancer cells were recovered and 99% of blood lymphocytes were removed. Most of the cancer cells recovered were viable (94%) and could be cultivated for >8 days, during which period they retained their normal cell morphology and proliferation rates. The recovery rate correlated closely with cancer-cell loadings in spiked samples and this relationship was linear over a range of at least 2 orders of magnitude. Importantly, because of the 3D structure of the rings, these results were obtained at a high cell-loading concentration (10(7)cells/mL). The rings could be further optimized for use in accurate label-free identification and measurement of circulating tumor cells in cancer research and disease management.

  4. Analysis of Intra- and Extracellular Levels of Purine Bases, Nucleosides, and Nucleotides in HepG2 Cells by High-performance Liquid Chromatography.

    PubMed

    Fukuuchi, Tomoko; Yamaoka, Noriko; Kaneko, Kiyoko

    2015-01-01

    To evaluate cellular uptake and purine transport, we developed a high-performance liquid chromatography method for intra- and extracellular purine quantification. Our aim was to develop an effective method for simultaneously quantifying the substrate and metabolites with high sensitivity. C18 columns from different manufacturers were tested for simultaneous quantification of 22 different purine bases, nucleosides, and nucleotides. We used a YMC-Triart C18 column. The analysis conditions, including extraction solutions for the cells and cell culture medium, were optimized to achieve good quantification. Linearity, accuracy, determination limits, and recovery were assessed and showed good performance. The developed HPLC method was successfully applied to the qualitative analysis of 22 different intra- and extracellular purines, demonstrating that it is useful for studying the overall pattern of purine metabolism. This method could also be useful for evaluating metabolic dynamics of purines under a variety of stimulatory conditions of culture cells.

  5. High-Performance Small Molecule/Polymer Ternary Organic Solar Cells Based on a Layer-By-Layer Process.

    PubMed

    Chen, Weichao; Du, Zhengkun; Xiao, Manjun; Zhang, Jidong; Yang, Chunpeng; Han, Liangliang; Bao, Xichang; Yang, Renqiang

    2015-10-21

    The layer-by-layer process method, which had been used to fabricate a bilayer or bulk heterojunction organic solar cell, was developed to fabricate highly efficient ternary blend solar cells in which small molecules and polymers act as two donors. The active layer could be formed by incorporating the small molecules into the polymer based active layer via a layer-by-layer method: the small molecules were first coated on the surface of poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) ( PSS), and then the mixed solution of polymer and fullerene derivative was spin-coated on top of a small molecule layer. In this method, the small molecules in crystalline state were effectively mixed in the active layer. Without further optimization of the morphology of the ternary blend, a high power conversion efficiency (PCE) of 8.76% was obtained with large short-circuit current density (Jsc) (17.24 mA cm(-2)) and fill factor (FF) (0.696). The high PCE resulted from not only enhanced light harvesting but also more balanced charge transport by incorporating small molecules.

  6. Elucidating the Reaction Pathways in the Synthesis of Organolead Trihalide Perovskite for High-Performance Solar Cells

    PubMed Central

    Wang, Baohua; Young Wong, King; Xiao, Xudong; Chen, Tao

    2015-01-01

    The past two years have witnessed unprecedentedly rapid development of organic–inorganic halide perovskite–based solar cells. The solution–processability and high efficiency make this technology extraordinarily attractive. The intensive investigations have accumulated rich experiences in the perovskite fabrication; while the mechanism of the chemical synthesis still remains unresolved. Here, we set up the chemical equation of the synthesis and elucidate the reactions from both thermodynamic and kinetic perspectives. Our study shows that gaseous products thermodynamically favour the reaction, while the activation energy and “collision” probability synergistically determine the reaction rate. These understandings enable us to finely tune the crystal size for high-quality perovskite film, leading to a record fill factor among similar device structures in the literature. This investigation provides a general strategy to explore the mechanism of perovskite synthesis and benefits the fabrication of high–efficiency perovskite photoactive layer. PMID:26020476

  7. Synchronously reduced surface states, charge recombination, and light absorption length for high-performance organic dye-sensitized solar cells.

    PubMed

    Li, Renzhi; Liu, Jingyuan; Cai, Ning; Zhang, Min; Wang, Peng

    2010-04-08

    We employ the 4,4-dihexyl-4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) segment as a conjugated spacer to construct an extremely high-molar-absorption-coefficient organic chromophore for dye-sensitized solar cells, exhibiting a high power conversion efficiency of 8.95% measured under irradiation of 100 mW cm(-2) AM1.5G sunlight. Our comparative experiments have proved the prominent merit of employing CPDT instead of the prevailing 2,2'-dithiophene (DT) as the building block for the further dye design. We also have demonstrated that a controllable coassembling of dye molecules and electrolyte components on semiconducting nanocrystals can reduce surface states and inhibit charge recombination synchronously.

  8. Analysis of oxysterols and vitamin D metabolites in mouse brain and cell line samples by ultra-high-performance liquid chromatography-atmospheric pressure photoionization-mass spectrometry.

    PubMed

    Ahonen, Linda; Maire, Florian B R; Savolainen, Mari; Kopra, Jaakko; Vreeken, Rob J; Hankemeier, Thomas; Myöhänen, Timo; Kylli, Petri; Kostiainen, Risto

    2014-10-17

    We have developed an ultra-high-performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometric (UHPLC-APPI-MS/MS) method for the simultaneous quantitative analyses of several oxysterols and vitamin D metabolites in mouse brain and cell line samples. An UHPLC-APPI-high resolution mass spectrometric (UHPLC-APPI-HRMS) method that uses a quadrupole-time of flight mass spectrometer was also developed for confirmatory analysis and for the identification of non-targeted oxysterols. Both methods showed good quantitative performance. Furthermore, APPI provides high ionization efficiency for determining oxysterols and vitamin D related compounds without the time consuming derivatization step needed in the conventionally used electrospray ionization method to achieve acceptable sensitivity. Several oxysterols were quantified in mouse brain and cell line samples. Additionally, 25-hydroxyvitamin D3 was detected in mouse brain samples for the first time.

  9. High Performance Thin Layer Chromatography.

    ERIC Educational Resources Information Center

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  10. High Performance Thin Layer Chromatography.

    ERIC Educational Resources Information Center

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  11. Development of high-performance cathode catalyst of polypyrrole modified carbon supported CoOOH for direct borohydride fuel cell

    NASA Astrophysics Data System (ADS)

    He, Yan; Zhu, Cai; Chen, Kaijian; Wang, Juan; Qin, Haiying; Liu, Jiabin; Yan, Shuai; Yang, Ke; Li, Aiguo

    2017-01-01

    Polypyrrole modified carbon supported CoOOH electrocatalyst (CoOOH-PPy-C) is prepared by impregnation-chemical method, and the catalytic properties for the oxygen reduction reaction (ORR) in alkaline media are investigated. The X-ray diffraction and transmission electron microscopy results confirm the presence of the expected CoOOH. The electrochemical tests show that the CoOOH-PPy-C catalyst exhibits good electrocatalytic activity towards ORR. The direct borohydride fuel cell using CoOOH-PPy-C as the cathode catalyst demonstrates a good stability performance. There is only 4% decrease of the cell voltage after 80-h operation. The ORR occurs an average 4-electron transfer pathway on the CoOOH-PPy-C catalyst. The good catalytic activity towards ORR benefits from the Cosbnd N bond, which is identified by X-ray photoelectron spectroscopy test. X-ray absorption fine structure experiments further show that two nearest O atoms are substituted by two N atoms bonding to Co ion at a distance of 1.64 Å. The CoOOH-PPy-C exhibits better electrochemical properties than the Co(OH)2 counterpart even though the valence state of Co ion is +3 in CoOOH-PPy-C. Those results indicate that the bonding of Co ion with N atoms should be a key issue regardless the valence of Co ion.

  12. Role of the gadolinia-doped ceria interlayer in high-performance intermediate-temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Jung, Doh Won; Kwak, Chan; Seo, Sooyeon; Moon, Kyoung-Seok; Han, In-taek; Kim, Ju Sik

    2017-09-01

    In this study, Ba0.5Sr0.5Co0.8Fe0.1Zn0.1O3-δ (BSCFZ) is used as a cathode with anode-supported scandia-stabilized zirconia (ScSZ) as the electrolyte to achieve intermediate-temperature solid oxide fuel cells (SOFCs). A gadolinia-doped ceria (GDC) interlayer is used between the BSCFZ cathode and the ScSZ electrolyte to protect ScSZ against interfacial reaction with the Co-containing cathode. However, an unfavorable reaction occurs at the GDC/ScSZ interface when the sintering temperature of the GDC interlayer is higher than 1200 °C. Thus, the performance of anode-supported SOFCs with GDC interlayers prepared at different sintering temperatures has been evaluated using I-V measurements and AC impedance spectroscopy. The results demonstrate that the sintering temperature of the GDC interlayer should be optimized for both the reaction between the BSCFZ cathode and ScSZ electrolyte and the reaction at the GDC/ScSZ interface. A maximum power density of 0.78 W cm-2 has been achieved at 700 °C with a GDC interlayer sintered at 1200 °C. Furthermore, the cell with the optimized GDC interlayer has been shown to maintain excellent reliability with respect to load cycling and thermal cycling.

  13. Orienting the Microstructure Evolution of Copper Phthalocyanine as an Anode Interlayer in Inverted Polymer Solar Cells for High Performance.

    PubMed

    Li, Zhiqi; Liu, Chunyu; Zhang, Xinyuan; Li, Shujun; Zhang, Xulin; Guo, Jiaxin; Guo, Wenbin; Zhang, Liu; Ruan, Shengping

    2017-09-20

    Recent advances in the interfacial modification of inverted-type polymer solar cells (PSCs) have resulted from controlling the surface energy of the cathode-modified layer (TiO2 or ZnO) to enhance the short-circuit current (Jsc) or optimizing the contact morphology of the cathode (indium tin oxide or fluorine-doped tin oxide) and active layer to increase the fill factor. Herein, we report that the performance enhancement of PSCs is achieved by incorporating a donor macromolecule copper phthalocyanine (CuPc) as an anode modification layer. Using the approach based on orienting the microstructure evolution, uniformly dispersed island-shaped CuPc spot accumulations are built on the top of PTB7:PC71BM blend film, leading to an efficient spectral absorption and photogenerated exciton splitting. The best power conversion efficiency of PSCs is increased up to 9.726%. In addition to the enhanced light absorption, the tailored anode energy level alignment and optimized boundary morphology by incorporating the CuPc interlayer boost charge extraction efficiency and suppress the interfacial molecular recombination. These results demonstrate that surface morphology induction through molecular deposition is an effective method to improve the performance of PSCs, which reveals the potential implications of the interlayer between the organic active layer and the electrode buffer layer.

  14. Recent advances in the development and utilization of modern anode materials for high performance microbial fuel cells.

    PubMed

    Sonawane, Jayesh M; Yadav, Abhishek; Ghosh, Prakash C; Adeloju, Samuel B

    2017-04-15

    Microbial fuel cells (MFCs) are novel bio-electrochemical device for spontaneous or single step conversion of biomass into electricity, based on the use of metabolic activity of bacteria. The design and use of MFCs has attracted considerable interests because of the potential new opportunities they offer for sustainable production of energy from biodegradable and reused waste materials. However, the associated slow microbial kinetics and costly construction materials has limited a much wider commercial use of the technology. In the past ten years, there has been significant new developments in MFCs which has resulted in several-fold increase in achievable power density. Yet, there is still considerable possibility for further improvement in performance and development of new cost effective materials. This paper comprehensively reviews recent advances in the construction and utilization of novel anodes for MFCs. In particular, it highlights some of the critical roles and functions of anodes in MFCs, strategies available for improving surface areas of anodes, dominant performance of stainless-steel based anode materials, and the emerging benefits of inclusion of nanomaterials. The review also demonstrates that some of the materials are very promising for large scale MFC applications and are likely to replace conventional anodes for the development of next generation MFC systems. The hurdles to the development of commercial MFC technology are also discussed. Furthermore, the future directions in the design and selection of materials for construction and utilization of MFC anodes are highlighted. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Enhancing dye-sensitized solar cell performances by molecular engineering: highly efficient π-extended organic sensitizers.

    PubMed

    Grisorio, Roberto; De Marco, Luisa; Agosta, Rita; Iacobellis, Rosabianca; Giannuzzi, Roberto; Manca, Michele; Mastrorilli, Piero; Gigli, Giuseppe; Suranna, Gian Paolo

    2014-09-01

    This study deals with the synthesis and characterization of two π-extended organic sensitizers (G1 and G2) for applications in dye-sensitized solar cells. The materials are designed with a D-A-π-A structure constituted by i) a triarylamine group as the donor part, ii) a dithienyl-benzothiadiazole chromophore followed by iii) a further ethynylene-thiophene (G1) or ethynylene-benzene (G2) π-spacer and iv) a cyano-acrylic moiety as acceptor and anchoring part. An unusual structural extension of the π-bridge characterizes these structures. The so-configured sensitizers exhibit a broad absorption profile, the origin of which is supported by density functional theory. The absence of hypsochromic shifts as a consequence of deprotonation as well as notable optical and electrochemical stabilities are also observed. Concerning the performances in devices, electrochemical impedance spectroscopy indicates that the structural modification of the π-spacer mainly increases the electron lifetime of G2 with respect to G1. In devices, this feature translates into a superior power conversion efficiency of G2, reaching 8.1%. These results are comparable to those recorded for N719 and are higher with respect to literature congeners, supporting further structural engineering of the π-bridge extension in the search for better performing π-extended organic sensitizers.

  16. Performance degradation studies on an poly 2,5-benzimidazole high-temperature proton exchange membrane fuel cell using an accelerated degradation technique

    NASA Astrophysics Data System (ADS)

    Jung, Guo-Bin; Chen, Hsin-Hung; Yan, Wei-Mon

    2014-02-01

    In this work, the performance degradation of a poly 2,5-benzimidazole (ABPBI) based high-temperature proton exchange membrane fuel cell (HT-PEMFC) was examined using an accelerated degradation technique (ADT). Experiments using an ADT with 30 min intervals were performed by applying 1.5 V to a membrane electrode assembly (MEA) with hydrogen and nitrogen feeding to the anode and cathode, respectively, to simulate the high voltage generated during fuel cell shutdown and restart. The characterization of the MEAs was performed using in-situ and ex-situ electrochemical methods, such as polarization curves, AC impedance, and cyclic voltammetry (CV), and TEM imaging before and after the ADT experiments. The measured results demonstrated that the ADT testing could be used to dramatically reduce the duration of the degradation. The current output at 0.4 V decreased by 48% after performing ADT testing for 30 min. From the AC impedance, CV and RTGA measurements, the decline in cell performance was found to be primarily due to corrosion and thinning of the catalyst layer (or carbon support) during the first 30 min, leading to the dissolution and agglomeration of the platinum catalyst.

  17. Handbook of fuel cell performance

    SciTech Connect

    Benjamin, T.G.; Camara, E.H.; Marianowski, L.G.

    1980-05-01

    The intent of this document is to provide a description of fuel cells, their performances and operating conditions, and the relationship between fuel processors and fuel cells. This information will enable fuel cell engineers to know which fuel processing schemes are most compatible with which fuel cells and to predict the performance of a fuel cell integrated with any fuel processor. The data and estimates presented are for the phosphoric acid and molten carbonate fuel cells because they are closer to commercialization than other types of fuel cells. Performance of the cells is shown as a function of operating temperature, pressure, fuel conversion (utilization), and oxidant utilization. The effect of oxidant composition (for example, air versus O/sub 2/) as well as fuel composition is examined because fuels provided by some of the more advanced fuel processing schemes such as coal conversion will contain varying amounts of H/sub 2/, CO, CO/sub 2/, CH/sub 4/, H/sub 2/O, and sulfur and nitrogen compounds. A brief description of fuel cells and their application to industrial, commercial, and residential power generation is given. The electrochemical aspects of fuel cells are reviewed. The phosphoric acid fuel cell is discussed, including how it is affected by operating conditions; and the molten carbonate fuel cell is discussed. The equations developed will help systems engineers to evaluate the application of the phosphoric acid and molten carbonate fuel cells to commercial, utility, and industrial power generation and waste heat utilization. A detailed discussion of fuel cell efficiency, and examples of fuel cell systems are given.

  18. Hollow fiber cell fishing with high-performance liquid chromatography for rapid screening and analysis of an antitumor-active protoberberine alkaloid group from Coptis chinensis.

    PubMed

    Liu, Xi; Hu, Shuang; Chen, Xuan; Bai, Xiaohong

    2014-09-01

    A novel hollow fiber cell fishing procedure with high-performance liquid chromatography (HFCF-HPLC) was developed and used for rapid screening, fishing, and analysis of bioactive compounds from traditional Chinese medicines. Human breast cancer cell MCF7, mouse breast cancer cell MADB106, and gastric cancer cell SGC7901 were seeded on the internal surface of hollow fibers that were used to screen, fish, and analyze an antitumor-active protoberberine alkaloid group from Coptis chinensis decoction. The main variables that affect the HFCF-HPLC process were investigated and optimized. The surface properties of the hollow fiber-seeded cells, cell survival rate, non-specific binding between active centers in the hollow fiber and the target compounds, repeatability, reliability, and recovery of HFCF-HPLC were investigated in detail. Several active compounds structures that were screened from Coptis chinensis by using HFCF-HPLC were identified by comparing the retention time of the reference substances. The cell membrane and cell organelle were separated from MCF7 cells for a preliminary study of the target effect of active compounds on MCF7 cells. The living cell, cell membrane, and cell organelle fishing factors of the active compound, as the indexes of drug binding ability in HFCF-HPLC, were defined and discussed. In addition, tamoxifen as positive control substance and indomethacin as negative control substance were screened by using HFCF-HPLC to further verify the method's reliability. The results demonstrated that HFCF-HPLC is an effective, rapid, stable, and reliable method to screen and analyze bioactive compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Polydopamine as a promising candidate for the design of high performance and corrosion-tolerant polymer electrolyte fuel cell electrodes

    NASA Astrophysics Data System (ADS)

    Long, Hongtao; Del Frari, Doriane; Martin, Arnaud; Didierjean, Joffrey; Ball, Vincent; Michel, Marc; Ahrach, Hicham Ibn El

    2016-03-01

    Carbon materials such as carbon black or nanotubes suffer from degradation when subjected to harsh conditions occurring in a Polymer Electrolyte Membrane Fuel Cells (PEMFCs) electrode. Hence, nowadays it is more and more important to search for alternative support materials. The present work shows the results for the incorporation of alternative materials into PEMFCs electrode architectures. Commercially available Multi-Walled NanoTubes (MWNTs) are used as a support for Pt nanoparticles in combination with Polydopamine (PDA). The role of MWNTs is to confer a high electronic conductivity and help to form a porous network. On the other side the role of polydopamine is both to promote the proton conductivity similarly to ionomers such as Nafion and to protect the MWNTs against corrosion. The fuel cell polarization test shows a maximum power density of 780 mW cm-2 and a Pt utilization of 6051 mW mg(Pt)-1. The Pt utilization reached in this work is almost three times higher than for Pt/MWNTs electrodes containing the same Pt loading. Beside this, it is also shown for the first time that PDA serves as protective layer against carbon corrosion.

  20. High Performance Flexible Thermal Link

    NASA Astrophysics Data System (ADS)

    Sauer, Arne; Preller, Fabian

    2014-06-01

    The paper deals with the design and performance verification of a high performance and flexible carbon fibre thermal link.Project goal was to design a space qualified thermal link combining low mass, flexibility and high thermal conductivity with new approaches regarding selected materials and processes. The idea was to combine the advantages of existing metallic links regarding flexibility and the thermal performance of high conductive carbon pitch fibres. Special focus is laid on the thermal performance improvement of matrix systems by means of nano-scaled carbon materials in order to improve the thermal performance also perpendicular to the direction of the unidirectional fibres.One of the main challenges was to establish a manufacturing process which allows handling the stiff and brittle fibres, applying the matrix and performing the implementation into an interface component using unconventional process steps like thermal bonding of fibres after metallisation.This research was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi).

  1. Solution-processed and high-performance organic solar cells using small molecules with a benzodithiophene unit.

    PubMed

    Zhou, Jiaoyan; Zuo, Yi; Wan, Xiangjian; Long, Guankui; Zhang, Qian; Ni, Wang; Liu, Yongsheng; Li, Zhi; He, Guangrui; Li, Chenxi; Kan, Bin; Li, Miaomiao; Chen, Yongsheng

    2013-06-12

    Three small molecules named DR3TBDTT, DR3TBDTT-HD, and DR3TBD2T with a benzo[1,2-b:4,5-b']dithiophene (BDT) unit as the central building block have been designed and synthesized for solution-processed bulk-heterojunction solar cells. Power conversion efficiencies (PCEs) of 8.12% (certified 7.61%) and 8.02% under AM 1.5G irradiation (100 mW cm(-2)) have been achieved for DR3TBDTT- and DR3TBDT2T-based organic photovoltaic devices (OPVs) with PC71BM as the acceptor, respectively. The better PCEs were achieved by improving the short-circuit current density without sacrificing the high open-circuit voltage and fill factor through the strategy of incorporating the advantages of both conventional small molecules and polymers for OPVs.

  2. High Performance Networks for High Impact Science

    SciTech Connect

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  3. High-performance formamidinium-based perovskite solar cells via microstructure-mediated δ-to-α phase transformation

    DOE PAGES

    Liu, Tanghao; Zong, Yingxia; Zhou, Yuanyuan; ...

    2017-03-14

    The δ → α phase transformation is a crucial step in the solution-growth process of formamidinium-based lead triiodide (FAPbI3) hybrid organic–inorganic perovskite (HOIP) thin films for perovskite solar cells (PSCs). Because the addition of cesium (Cs) stabilizes the α phase of FAPbI3-based HOIPs, here our research focuses on FAPbI3(Cs) thin films. We show that having a large grain size in the δ-FAPbI3(Cs) non-perovskite intermediate films is essential for the growth of high-quality α-FAPbI3(Cs) HOIP thin films. Here grain coarsening and phase transformation occur simultaneously during the thermal annealing step. A large starting grain size in the δ-FAPbI3(Cs) thin films suppressesmore » grain coarsening, precluding the formation of voids at the final α-FAPbI3(Cs)–substrate interfaces. PSCs based on the interface void-free α-FAPbI3(Cs) HOIP thin films are much more efficient and stable in the ambient atmosphere. This interesting finding inspired us to develop a simple room-temperature aging method for preparing coarse-grained δ-FAPbI3(Cs) intermediate films, which are subsequently converted to coarse-grained, high-quality α-FAPbI3(Cs) HOIP thin films. As a result, this study highlights the importance of microstructure meditation in the processing of formamidinium-based PSCs.« less

  4. A Thieno[3,4-b]thiophene-Based Non-fullerene Electron Acceptor for High-Performance Bulk-Heterojunction Organic Solar Cells.

    PubMed

    Liu, Feng; Zhou, Zichun; Zhang, Cheng; Vergote, Thomas; Fan, Haijun; Liu, Feng; Zhu, Xiaozhang

    2016-12-07

    A thieno[3,4-b]thiophene-based electron acceptor, ATT-1, is designed and synthesized. ATT-1 exhibits a planar conjugated framework, broad absorption with a large absorption coefficient, and a slightly high LUMO energy level. Bulk-heterojunction (BHJ) solar cells based on PTB7-Th electron donor and ATT-1 electron acceptor delivered power conversion efficiencies of up to 10.07%, which is among the best performances reported for non-fullerene BHJ solar cells using PTB7-Th as the electron donor.

  5. High-Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Reuhs, Bradley L.; Rounds, Mary Ann

    High-performance liquid chromatography (HPLC) developed during the 1960s as a direct offshoot of classic column liquid chromatography through improvements in the technology of columns and instrumental components (pumps, injection valves, and detectors). Originally, HPLC was the acronym for high-pressure liquid chromatography, reflecting the high operating pressures generated by early columns. By the late 1970s, however, high-performance liquid chromatography had become the preferred term, emphasizing the effective separations achieved. In fact, newer columns and packing materials offer high performance at moderate pressure (although still high pressure relative to gravity-flow liquid chromatography). HPLC can be applied to the analysis of any compound with solubility in a liquid that can be used as the mobile phase. Although most frequently employed as an analytical technique, HPLC also may be used in the preparative mode.

  6. Crack-free CH3NH3PbI3 layer via continuous dripping method for high-performance mesoporous perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Chen, Guo; Zheng, Jianghui; Zheng, LingLing; Yan, Xin; Lin, Huangding; Zhang, Fengyan

    2017-01-01

    The past five years have witnessed the uniquely rapid emergence of the mixed organic-inorganic halide perovskite solar cells. Here, a modified deposition process, continuous dripping method, is reported for fabricating high-performance and reproducible perovskite solar cells. We have systematically investigated the impact of different molar ratio of lead iodide (PbI2) to dimethylsulfoxide (DMSO) on the growth, morphology and crystallinity of CH3NH3PbI3 (MAPbI3) films obtained via this process. The high power conversion efficiency (PCE) perovskite solar cell originates in crack-free and highly crystallographic perovskite films prepared with optimized ratio of PbI2 to DMSO in first precursor solution. The best PCE of 17.76% and an average PCE of 16.37 ± 0.51% were obtained via this process. Moreover, the conventional solution two steps method was also carried out as a comparison to this process. This work provides a new simple solution approach to obtain high quality of perovskite thin films for high-performance and reproducible PSCs.

  7. Screening antiallergic components from Carthamus tinctorius using rat basophilic leukemia 2H3 cell membrane chromatography combined with high-performance liquid chromatography and tandem mass spectrometry.

    PubMed

    Han, Shengli; Huang, Jing; Cui, Ronghua; Zhang, Tao

    2015-02-01

    Carthamus tinctorius, used in traditional Chinese medicine, has many pharmacological effects, such as anticoagulant effects, antioxidant effects, antiaging effects, regulation of gene expression, and antitumor effects. However, there is no report on the antiallergic effects of the components in C. tinctorius. In the present study, we investigated the antiallergic components of C. tinctorius and its mechanism of action. A rat basophilic leukemia 2H3/cell membrane chromatography coupled online with high-performance liquid chromatography and tandem mass spectrometry method was developed to screen antiallergic components from C. tinctorius. The screening results showed that Hydroxysafflor yellow A, from C. tinctorius, was the targeted component that retained on the rat basophilic leukemia 2H3/cell membrane chromatography column. We measured the amount of β-hexosaminidase and histamine released in mast cells and the key markers of degranulation. The release assays showed that Hydroxysafflor yellow A could attenuate the immunoglobulin E induced release of allergic cytokines without affecting cell viability from 1.0 to 50.0 μM. In conclusion, the established rat basophilic leukemia 2H3 cell membrane chromatography coupled with online high-performance liquid chromatography and tandem mass spectrometry method successfully screened and identified Hydroxysafflor yellow A from C. tinctorius as a potential antiallergic component. Pharmacological analysis elucidated that Hydroxysafflor yellow A is an effective natural component for inhibiting immunoglobulin E-antigen-mediated degranulation.

  8. Computer-aided 2D and 3D quantification of human stem cell fate from in vitro samples using Volocity high performance image analysis software.

    PubMed

    Piltti, Katja M; Haus, Daniel L; Do, Eileen; Perez, Harvey; Anderson, A J; Cummings, B J

    2011-11-01

    Accurate automated cell fate analysis of immunostained human stem cells from 2- and 3-dimensional (2D-3D) images would improve efficiency in the field of stem cell research. Development of an accurate and precise tool that reduces variability and the time needed for human stem cell fate analysis will improve productivity and interpretability of the data across research groups. In this study, we have created protocols for high performance image analysis software Volocity® to classify and quantify cytoplasmic and nuclear cell fate markers from 2D-3D images of human neural stem cells after in vitro differentiation. To enhance 3D image capture efficiency, we optimized the image acquisition settings of an Olympus FV10i® confocal laser scanning microscope to match our quantification protocols and improve cell fate classification. The methods developed in this study will allow for a more time efficient and accurate software based, operator validated, stem cell fate classification and quantification from 2D and 3D images, and yield the highest ≥94.4% correspondence with human recognized objects.

  9. Correlation between Hierarchical Structure and Processing Control of Large-area Spray-coated Polymer Solar Cells toward High Performance

    PubMed Central

    Huang, Yu-Ching; Tsao, Cheng-Si; Cha, Hou-Chin; Chuang, Chih-Min; Su, Chun-Jen; Jeng, U-Ser; Chen, Charn-Ying

    2016-01-01

    The formation mechanism of a spray-coated film is different from that of a spin-coated film. This study employs grazing incidence small- and wide-angle X-ray Scattering (GISAXS and GIWAXS, respectively) quantitatively and systematically to investigate the hierarchical structure and phase-separated behavior of a spray-deposited blend film. The formation of PCBM clusters involves mutual interactions with both the P3HT crystal domains and droplet boundary. The processing control and the formed hierarchical structure of the active layer in the spray-coated polymer/fullerene blend film are compared to those in the spin-coated film. How the different post-treatments, such as thermal and solvent vapor annealing, tailor the hierarchical structure of the spray-coated films is quantitatively studied. Finally, the relationship between the processing control and tailored BHJ structures and the performance of polymer solar cell devices is established here, taking into account the evolution of the device area from 1 × 0.3 and 1 × 1 cm2. The formation and control of the special networks formed by the PCBM cluster and P3HT crystallites, respectively, are related to the droplet boundary. These structures are favorable for the transverse transport of electrons and holes. PMID:26817585

  10. Correlation between Hierarchical Structure and Processing Control of Large-area Spray-coated Polymer Solar Cells toward High Performance.

    PubMed

    Huang, Yu-Ching; Tsao, Cheng-Si; Cha, Hou-Chin; Chuang, Chih-Min; Su, Chun-Jen; Jeng, U-Ser; Chen, Charn-Ying

    2016-01-28

    The formation mechanism of a spray-coated film is different from that of a spin-coated film. This study employs grazing incidence small- and wide-angle X-ray Scattering (GISAXS and GIWAXS, respectively) quantitatively and systematically to investigate the hierarchical structure and phase-separated behavior of a spray-deposited blend film. The formation of PCBM clusters involves mutual interactions with both the P3HT crystal domains and droplet boundary. The processing control and the formed hierarchical structure of the active layer in the spray-coated polymer/fullerene blend film are compared to those in the spin-coated film. How the different post-treatments, such as thermal and solvent vapor annealing, tailor the hierarchical structure of the spray-coated films is quantitatively studied. Finally, the relationship between the processing control and tailored BHJ structures and the performance of polymer solar cell devices is established here, taking into account the evolution of the device area from 1 × 0.3 and 1 × 1 cm(2). The formation and control of the special networks formed by the PCBM cluster and P3HT crystallites, respectively, are related to the droplet boundary. These structures are favorable for the transverse transport of electrons and holes.

  11. Tailoring the Mesoscopic TiO2 Layer: Concomitant Parameters for Enabling High-Performance Perovskite Solar Cells.

    PubMed

    Hwang, Taehyun; Lee, Sangheon; Kim, Jinhyun; Kim, Jaewon; Kim, Chunjoong; Shin, Byungha; Park, Byungwoo

    2017-12-01

    Architectural control over the mesoporous TiO2 film, a common electron-transport layer for organic-inorganic hybrid perovskite solar cells, is conducted by employing sub-micron sized polystyrene beads as sacrificial template. Such tailored TiO2 layer is shown to induce asymmetric enhancement of light absorption notably in the long-wavelength region with red-shifted absorption onset of perovskite, leading to ~20% increase of photocurrent and ~10% increase of power conversion efficiency. This enhancement is likely to be originated from the enlarged CH3NH3PbI3(Cl) grains residing in the sub-micron pores rather than from the effect of reduced perovskite-TiO2 interfacial area, which is supported from optical bandgap change, haze transmission of incident light, and one-diode model parameters correlated with the internal surface area of microporous TiO2 layers. With the templating strategy suggested, the necessity of proper hole-blocking method is discussed to prevent any direct contact of the large perovskite grains infiltrated into the intended pores of TiO2 scaffold, further mitigating the interfacial recombination and leading to ~20% improvement in power conversion efficiency compared with the control device using conventional solution-processed hole blocking TiO2. Thereby, the imperatives that originate from the structural engineering of the electron-transport layer are discussed to understand the governing elements for the improved device performance.

  12. Tailoring the Mesoscopic TiO2 Layer: Concomitant Parameters for Enabling High-Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Hwang, Taehyun; Lee, Sangheon; Kim, Jinhyun; Kim, Jaewon; Kim, Chunjoong; Shin, Byungha; Park, Byungwoo

    2017-01-01

    Architectural control over the mesoporous TiO2 film, a common electron-transport layer for organic-inorganic hybrid perovskite solar cells, is conducted by employing sub-micron sized polystyrene beads as sacrificial template. Such tailored TiO2 layer is shown to induce asymmetric enhancement of light absorption notably in the long-wavelength region with red-shifted absorption onset of perovskite, leading to 20% increase of photocurrent and 10% increase of power conversion efficiency. This enhancement is likely to be originated from the enlarged CH3NH3PbI3(Cl) grains residing in the sub-micron pores rather than from the effect of reduced perovskite-TiO2 interfacial area, which is supported from optical bandgap change, haze transmission of incident light, and one-diode model parameters correlated with the internal surface area of microporous TiO2 layers. With the templating strategy suggested, the necessity of proper hole-blocking method is discussed to prevent any direct contact of the large perovskite grains infiltrated into the intended pores of TiO2 scaffold, further mitigating the interfacial recombination and leading to 20% improvement in power conversion efficiency compared with the control device using conventional solution-processed hole blocking TiO2. Thereby, the imperatives that originate from the structural engineering of the electron-transport layer are discussed to understand the governing elements for the improved device performance.

  13. Propeller-shaped acceptors for high-performance non-fullerene solar cells: Importance of the rigidity of molecular geometry

    DOE PAGES

    Wu, Qinghe; Zhao, Donglin; Yang, Jinghui; ...

    2017-01-06

    This study describes the synthesis and application of βTPB6 and βTPB6-C as electron acceptors for organic solar cells. Compound βTPB6 contains four covalently bonded PDIs with a BDT-Th core at the β-position. The free rotation of PDIs renders βTPB6 with varying molecular geometries. The cyclization of βTPB6 yields βTPB6-C with high rigidity of the molecular geometry and enlarged conjugated skeleton. The inverted solar cells based on βTPB6-C and PTB7-Th as the donor polymer exhibited the highest efficiency of 7.69% with Voc of 0.92 V, Jsc of 14.9 mAcm–2, and FF of 0.56, which is 31% higher than that for βTPB6more » based devices. The larger fraction of βTPB6-C and PTB7-Th than that of βTPB6:PTB7-Th in a blend film takes a face-on orientation packing pattern for π-systems that benefits the charge transport and hence higher PCE value than that for βTPB6:PTB7-Th. It was also found that a proper DIO:DPE additive further enhances this trend, which results in an increase of the PCE value for βTPB6-C:PTB7-Th while decreasing the PCE value for βTPB6:PTB7-Th.« less

  14. High Performance Ceramic Interconnect Material for Solid Oxide Fuel Cells (SOFCs): Ca- and Transition Metal-doped Yttrium Chromite

    SciTech Connect

    Yoon, Kyung J.; Stevenson, Jeffry W.; Marina, Olga A.

    2011-10-15

    The effect of transition metal substitution on thermal and electrical properties of Ca-doped yttrium chromite was investigated in relation to use as a ceramic interconnect in high temperature solid oxide fuel cells (SOFCs). 10 at% Co, 4 at% Ni, and 1 at% Cu substitution on B-site of 20 at% Ca-doped yttrium chromite led to a close match of thermal expansion coefficient (TEC) with that of 8 mol% yttria-stabilized zirconia (YSZ), and a single phase Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 remained stable between 25 and 1100 degree C over a wide oxygen partial pressure range. Doping with Cu significantly facilitated densification of yttrium chromite. Ni dopant improved both electrical conductivity and dimensional stability in reducing environments, likely through diminishing the oxygen vacancy formation. Substitution with Co substantially enhanced electrical conductivity in oxidizing atmosphere, which was attributed to an increase in charge carrier density and hopping mobility. Electrical conductivity of Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 at 900 degree C is 57 S/cm in air and 11 S/cm in fuel (pO2=5×10^-17 atm) environments. Chemical compatibility of doped yttrium chromite with other cell components was verified at the processing temperatures. Based on the chemical and dimensional stability, sinterability, and thermal and electrical properties, Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 is suggested as a promising SOFC ceramic interconnect to potentially overcome technical limitations of conventional acceptor-doped lanthanum chromites.

  15. High-performance Förster resonance energy transfer (FRET)-based dye-sensitized solar cells: rational design of quantum dots for wide solar-spectrum utilization.

    PubMed

    Lee, Eunwoo; Kim, Chanhoi; Jang, Jyongsik

    2013-07-29

    High-performance Förster resonance energy transfer (FRET)-based dye-sensitized solar cells (DSSCs) have been successfully fabricated through the optimized design of a CdSe/CdS quantum-dot (QD) donor and a dye acceptor. This simple approach enables quantum dots and dyes to simultaneously utilize the wide solar spectrum, thereby resulting in high conversion efficiency over a wide wavelength range. In addition, major parameters that affect the FRET interaction between donor and acceptor have been investigated including the fluorescent emission spectrum of QD, and the content of deposited QDs into the TiO2 matrix. By judicious control of these parameters, the FRET interaction can be readily optimized for high photovoltaic performance. In addition, the as-synthesized water-soluble quantum dots were highly dispersed in a nanoporous TiO2 matrix, thereby resulting in excellent contact between donors and acceptors. Importantly, high-performance FRET-based DSSCs can be prepared without any infrared (IR) dye synthetic procedures. This novel strategy offers great potential for applications of dye-sensitized solar cells.

  16. Multilayer high performance insulation materials

    NASA Technical Reports Server (NTRS)

    Stuckey, J. M.

    1971-01-01

    A number of tests are required to evaluate both multilayer high performance insulation samples and the materials that comprise them. Some of the techniques and tests being employed for these evaluations and some of the results obtained from thermal conductivity tests, outgassing studies, effect of pressure on layer density tests, hypervelocity impact tests, and a multilayer high performance insulation ambient storage program at the Kennedy Space Center are presented.

  17. High Efficiency IMM Solar Cells

    NASA Astrophysics Data System (ADS)

    Sharps, P.; Cho, B.; Chumney, D.; Cornfeild, A.; Guzie, B.; Hazlett, D.; Lin, Y.; Mackos, C.; Patel, P.; Stan, M.; Steinfeldt, J.; Tourino, C.

    2014-08-01

    We review the status of currently available commercial multi-junction cells, review options for next generation high efficiency cell architectures, and present the latest developments on the inverted metamorphic multi- junction (IMM) solar cell. Over 20,000 IMM cells have been prototyped to date, and efficiencies of up to 37% have been measured. We present the most recent performance data, including the response to particle radiation. The IMM cell can be used in a number of rigid or flexible configurations, and considerable effort is currently focused on cell packaging and panel integration. We discuss several design options, including a "drop in" replacement for the current 29.5% ZTJ cell technology. We will also address the reliability and cost of the IMM cell.

  18. A facile, solvent vapor-fumigation-induced, self-repair recrystallization of CH3NH3PbI3 films for high-performance perovskite solar cells.

    PubMed

    Zhu, Weidong; Yu, Tao; Li, Faming; Bao, Chunxiong; Gao, Hao; Yi, Yong; Yang, Jie; Fu, Gao; Zhou, Xiaoxin; Zou, Zhigang

    2015-03-12

    A high-quality CH3NH3PbI3 film is crucial in the manufacture of a high-performance perovskite solar cell. Here, a recrystallization process via facile fumigation with DMF vapor has been successfully introduced to self-repair of CH3NH3PbI3 films with poor coverage and low crystallinity prepared by the commonly used one-step spin-coating method. We found that the CH3NH3PbI3 films with dendritic structures can spontaneously transform to the uniform ones with full coverage and high crystallinity by adjusting the cycles of the recrystallization process. The mesostructured perovskite solar cells based on these repaired CH3NH3PbI3 films showed reproducible optimal power conversion efficiency (PCE) of 11.15% and average PCE of 10.25±0.90%, which are much better than that of devices based on the non-repaired CH3NH3PbI3 films. In addition, the hysteresis phenomenon in the current-voltage test can also be effectively alleviated due to the quality of the films being improved in the optimized devices. Our work proved that the fumigation of solvent vapor can modify metal organic perovskite films such as CH3NH3PbI3. It offers a novel and attractive way to fabricate high-performance perovskite solar cells.

  19. Method for improving fuel cell performance

    DOEpatents

    Uribe, Francisco A.; Zawodzinski, Thomas

    2003-10-21

    A method is provided for operating a fuel cell at high voltage for sustained periods of time. The cathode is switched to an output load effective to reduce the cell voltage at a pulse width effective to reverse performance degradation from OH adsorption onto cathode catalyst surfaces. The voltage is stepped to a value of less than about 0.6 V to obtain the improved and sustained performance.

  20. High performance flexible heat pipes

    NASA Technical Reports Server (NTRS)

    Shaubach, R. M.; Gernert, N. J.

    1985-01-01

    A Phase I SBIR NASA program for developing and demonstrating high-performance flexible heat pipes for use in the thermal management of spacecraft is examined. The program combines several technologies such as flexible screen arteries and high-performance circumferential distribution wicks within an envelope which is flexible in the adiabatic heat transport zone. The first six months of work during which the Phase I contract goal were met, are described. Consideration is given to the heat-pipe performance requirements. A preliminary evaluation shows that the power requirement for Phase II of the program is 30.5 kilowatt meters at an operating temperature from 0 to 100 C.

  1. High performance flexible heat pipes

    NASA Technical Reports Server (NTRS)

    Shaubach, R. M.; Gernert, N. J.

    1985-01-01

    A Phase I SBIR NASA program for developing and demonstrating high-performance flexible heat pipes for use in the thermal management of spacecraft is examined. The program combines several technologies such as flexible screen arteries and high-performance circumferential distribution wicks within an envelope which is flexible in the adiabatic heat transport zone. The first six months of work during which the Phase I contract goal were met, are described. Consideration is given to the heat-pipe performance requirements. A preliminary evaluation shows that the power requirement for Phase II of the program is 30.5 kilowatt meters at an operating temperature from 0 to 100 C.

  2. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells.

    PubMed

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-12-09

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm(-1) in 5% H2 and peak power densities of 1.72 and 0.54 W cm(-2) using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm(-2). To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode.

  3. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-12-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm-1 in 5% H2 and peak power densities of 1.72 and 0.54 W cm-2 using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm-2. To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode.

  4. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells

    PubMed Central

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-01-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm−1 in 5% H2 and peak power densities of 1.72 and 0.54 W cm−2 using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm−2. To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode. PMID:26648509

  5. High-Performance Regular Perovskite Solar Cells Employing Low-Cost Poly(ethylenedioxythiophene) as a Hole-Transporting Material

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaoqing; Yu, Ze; Zhang, Yuchen; Lai, Jianbo; Li, Jiajia; Gurzadyan, Gagik G.; Yang, Xichuan; Sun, Licheng

    2017-02-01

    Herein, we successfully applied a facile in-situ solid-state synthesis of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as a HTM, directly on top of the perovskite layer, in conventional mesoscopic perovskite solar cells (PSCs) (n-i-p structure). The fabrication of the PEDOT film only involved a very simple in-situ solid-state polymerisation step from a monomer 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) made from a commercially available and cheap starting material. The ultraviolet photoelectron spectroscopy (UPS) demonstrated that the as-prepared PEDOT film possesses the highest occupied molecular orbital (HOMO) energy level of -5.5 eV, which facilitates an effective hole extraction from the perovskite absorber as confirmed by the photoluminescence measurements. Optimised PSC devices employing this polymeric HTM in combination with a low-cost vacuum-free carbon cathode (replacing the gold), show an excellent power conversion efficiency (PCE) of 17.0% measured at 100 mW cm-2 illumination (AM 1.5G), with an open-circuit voltage (Voc) of 1.05 V, a short-circuit current density (Jsc) of 23.5 mA/cm2 and a fill factor (FF) of 0.69, respectively. The present finding highlights the potential application of PEDOT made from solid-state polymerisation as a HTM for cost-effective and highly efficient PSCs.

  6. Investigation into the Advantages of Pure Perovskite Film without PbI2 for High Performance Solar Cell

    PubMed Central

    Kwon, Uisik; Hasan, Md Mehedi; Yin, Wenping; Kim, Dasom; Ha, Na Young; Lee, Soonil; Ahn, Tae Kyu; Park, Hui Joon

    2016-01-01

    In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2 impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2 forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2 impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2 impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured. PMID:27786257

  7. Advanced cell technology for high performance Li-A1/FeS{sub 2} secondary batteries.

    SciTech Connect

    Henriksen, G. L.

    1998-07-10

    In early 1993. Argonne National Laboratory (ANL) initiated a major R and D effort to develop bipolar Li-Al/LiCl-LiBr-KBr/FeS{sub 2} batteries for electric vehicles, targeting the USABC Long-Term Goals. Significant advancements were achieved in the areas of (i) chemical purity, (ii) electrode and electrolyte additives, and (iii) peripheral seals. It was determined that key chemical constituents contained undesirable impurities. ANL developed new chemical processes for preparing Li{sub 2}S, FeS, and CoS{sub 2} that were >98.5% pure. We evaluated a large variety of electrode and electrolyte additives for reducing cell area specific impedance (ASI). Candidate positive electrode additives offered increased electronic conductivity, enhanced reaction kinetics, and/or improved porous electrode morphology. CoS{sub 2}, CuFeS{sub 2}, MgO, and graphite (fibers) were identified as the most beneficial impedance-reducing positive electrode additives. Although electronically conductive carbon and graphite additives produced measurable ASI reductions in the negative electrode, they degraded its structural integrity and were deemed impractical. Lil and LiF were identified as beneficial electrolyte additives, that enhance positive electrode kinetics. ANL refined its baseline metal/ceramic peripheral seal and increased its strength by a factor of three (achieving a safety factor >10). In parallel, ANL developed a high-strength advanced metal/ceramic seal that offers appreciable cost reductions.

  8. High Performance of Perovskite Solar Cells via Catalytic Treatment in Two-Step Process: The Case of Solvent Engineering.

    PubMed

    Li, Wenzhe; Fan, Jiandong; Li, Jiangwei; Niu, Guangda; Mai, Yaohua; Wang, Liduo

    2016-11-09

    Currently, the potential mechanism of the solvent-assisted crystallization for mixed cations perovskite thin film (FAxMA1-xPbI3) prepared via two-step solution-process still remains obscure. Here, we clarified the molecular-competing-reacted process of NH2CH═NH2I (FAI) and CH3NH3I (MAI) with PbI2(DMSO)x complex in dimethyl sulfoxide (DMSO) and diethyl ether (DE) catalytic solvent system in the sequential two-step solution-process. The microscopic dynamics was characterized via the characterizations of in situ photoluminescence spectra. In addition, we found that the thermal stability of the perovskite films suffered from the residual solvent with high boiling point, for example, DMSO. The further DE treatment could promote the volatility process of DMSO and accelerate the crystallization process of perovskite films. The highest PCE over 19% with slight hysteresis effect was eventually obtained with a reproducible FA0.88MA0.12PbI3 solar cell, which displayed a constant power output within 100 s upon light soaking and stable PCE output within 30 d in the thermal stability test.

  9. High-Performance Regular Perovskite Solar Cells Employing Low-Cost Poly(ethylenedioxythiophene) as a Hole-Transporting Material.

    PubMed

    Jiang, Xiaoqing; Yu, Ze; Zhang, Yuchen; Lai, Jianbo; Li, Jiajia; Gurzadyan, Gagik G; Yang, Xichuan; Sun, Licheng

    2017-02-13

    Herein, we successfully applied a facile in-situ solid-state synthesis of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as a HTM, directly on top of the perovskite layer, in conventional mesoscopic perovskite solar cells (PSCs) (n-i-p structure). The fabrication of the PEDOT film only involved a very simple in-situ solid-state polymerisation step from a monomer 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) made from a commercially available and cheap starting material. The ultraviolet photoelectron spectroscopy (UPS) demonstrated that the as-prepared PEDOT film possesses the highest occupied molecular orbital (HOMO) energy level of -5.5 eV, which facilitates an effective hole extraction from the perovskite absorber as confirmed by the photoluminescence measurements. Optimised PSC devices employing this polymeric HTM in combination with a low-cost vacuum-free carbon cathode (replacing the gold), show an excellent power conversion efficiency (PCE) of 17.0% measured at 100 mW cm(-2) illumination (AM 1.5G), with an open-circuit voltage (Voc) of 1.05 V, a short-circuit current density (Jsc) of 23.5 mA/cm(2) and a fill factor (FF) of 0.69, respectively. The present finding highlights the potential application of PEDOT made from solid-state polymerisation as a HTM for cost-effective and highly efficient PSCs.

  10. Investigation into the Advantages of Pure Perovskite Film without PbI2 for High Performance Solar Cell.

    PubMed

    Kwon, Uisik; Hasan, Md Mehedi; Yin, Wenping; Kim, Dasom; Ha, Na Young; Lee, Soonil; Ahn, Tae Kyu; Park, Hui Joon

    2016-10-27

    In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2 impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2 forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2 impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2 impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured.

  11. Mass balance research for high electrochemical performance direct methanol fuel cells with reduced methanol crossover at various operating conditions

    NASA Astrophysics Data System (ADS)

    Park, Jun-Young; Lee, Jin-Hwa; Kang, SangKyun; Sauk, Jun-Ho; Song, Inseob

    Mass balance research in direct methanol fuel cells (DMFCs) provides a more practical method in characterizing the mass transport phenomena in a membrane electrode assembly (MEA). This method can be used to measure methanol utilization efficiency, water transport coefficient (WTC), and methanol to electricity conversion rate of a MEA in DMFCs. First, the vital design parameters of a MEA are recognized for achieving high methanol utilization efficiency with increased power density. In particular, the structural adjustment of anode diffusion layer by adding microporous layer (MPL) is a very effective way to decrease WTC with reduced methanol crossover due to the mass transfer limitation in the anode. On the other hand, the cathode MPL in the MEA design can contribute in decreasing methanol crossover. The change of structure of cathode diffusion layer is also found to be a very effective way in improving power density. In contrast, the WTC of DMFC MEAs remains virtually constant in the range of 3.4 and 3.6 irrespective of the change of the cathode GDL. The influence of operating condition on the methanol utilization efficiency, WTC, and methanol to electricity conversion rate is also presented and it is found that these mass balance properties are strongly affected by temperature, current density, methanol concentration, and the stoichiometry of fuel and air.

  12. Investigation into the Advantages of Pure Perovskite Film without PbI2 for High Performance Solar Cell

    NASA Astrophysics Data System (ADS)

    Kwon, Uisik; Hasan, Md Mehedi; Yin, Wenping; Kim, Dasom; Ha, Na Young; Lee, Soonil; Ahn, Tae Kyu; Park, Hui Joon

    2016-10-01

    In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2 impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2 forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2 impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2 impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured.

  13. High-Performance Regular Perovskite Solar Cells Employing Low-Cost Poly(ethylenedioxythiophene) as a Hole-Transporting Material

    PubMed Central

    Jiang, Xiaoqing; Yu, Ze; Zhang, Yuchen; Lai, Jianbo; Li, Jiajia; Gurzadyan, Gagik G.; Yang, Xichuan; Sun, Licheng

    2017-01-01

    Herein, we successfully applied a facile in-situ solid-state synthesis of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as a HTM, directly on top of the perovskite layer, in conventional mesoscopic perovskite solar cells (PSCs) (n-i-p structure). The fabrication of the PEDOT film only involved a very simple in-situ solid-state polymerisation step from a monomer 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) made from a commercially available and cheap starting material. The ultraviolet photoelectron spectroscopy (UPS) demonstrated that the as-prepared PEDOT film possesses the highest occupied molecular orbital (HOMO) energy level of −5.5 eV, which facilitates an effective hole extraction from the perovskite absorber as confirmed by the photoluminescence measurements. Optimised PSC devices employing this polymeric HTM in combination with a low-cost vacuum-free carbon cathode (replacing the gold), show an excellent power conversion efficiency (PCE) of 17.0% measured at 100 mW cm−2 illumination (AM 1.5G), with an open-circuit voltage (Voc) of 1.05 V, a short-circuit current density (Jsc) of 23.5 mA/cm2 and a fill factor (FF) of 0.69, respectively. The present finding highlights the potential application of PEDOT made from solid-state polymerisation as a HTM for cost-effective and highly efficient PSCs. PMID:28211919

  14. Highly efficient hybrid solar cell using ZnO nanorods and assessment of changes in cell performance by varying the growth period

    NASA Astrophysics Data System (ADS)

    Mehrabian, Masood; Aslyousefzadeh, Sonya; Maleki, M. Hadi

    2015-05-01

    Zinc oxide nanorod arrays (ZnO NRs) were grown from ZnO seed-coated substrates in an aqueous solution by using the hydrothermal method for different growth periods varying from 5 min to 1 hour. The influence of the growth period of the ZnO nanorods on photovoltaic applications was studied in detail. Experimental results showed that utilization of the nanorod arrays lead to an enhanced the cell performance by increasing of light absorption and creation of a vertical direction for electron transport in the solar cells. A power conversion efficiency of 3.33% with an opencircuit voltage of V OC = 0.58 V, a short-circuit current of J SC = 10.05 mA/cm2 and a fill factor of FF = 54.35% was achieved for solar cells based on ZnO NRs with growth period of 20 min. Such solar cells with an optimal growth period are effective in light trapping, which leads to a significant enhancement in the absorption of light, and thereby, show an obvious increase in the power conversion efficiency.

  15. High performance dielectric materials development

    NASA Astrophysics Data System (ADS)

    Piche, Joe; Kirchner, Ted; Jayaraj, K.

    1994-09-01

    The mission of polymer composites materials technology is to develop materials and processing technology to meet DoD and commercial needs. The following are outlined in this presentation: high performance capacitors, high temperature aerospace insulation, rationale for choosing Foster-Miller (the reporting industry), the approach to the development and evaluation of high temperature insulation materials, and the requirements/evaluation parameters. Supporting tables and diagrams are included.

  16. High performance dielectric materials development

    NASA Technical Reports Server (NTRS)

    Piche, Joe; Kirchner, Ted; Jayaraj, K.

    1994-01-01

    The mission of polymer composites materials technology is to develop materials and processing technology to meet DoD and commercial needs. The following are outlined in this presentation: high performance capacitors, high temperature aerospace insulation, rationale for choosing Foster-Miller (the reporting industry), the approach to the development and evaluation of high temperature insulation materials, and the requirements/evaluation parameters. Supporting tables and diagrams are included.

  17. Rapid differentiation of Ralstonia solanacearum avirulent and virulent strains by cell fractioning of an isolate using high performance liquid chromatography.

    PubMed

    Zheng, Xuefang; Zhu, Yujing; Liu, Bo; Yu, Qian; Lin, Naiquan

    2016-01-01

    Ralstonia solanacearum is one of the most destructive plant bacterial pathogens worldwide. The population dynamics and genetic stability are important issues, especially when an avirulent strain is used for biocontrol. In this study, we developed a rapid method to differentiate the virulent and avirulent strains of R. solanacearum and to predict the biocontrol efficiency of an avirulent strain using high performance liquid chromatography (HPLC). Three chromatographic peaks P1, P2 and P3 were observed on the HPLC spectra among 68 avirulent and 28 virulent R. solanacearum strains. Based on the HPLC peaks, 96 strains total were assigned to three categories. For avirulent strains, the intense peak is P1, while for virulent strains, P3 is the majority. Based on the HLPC spectra of R. solanacearum strains, a chromatography titer index (CTI) was established as CTIi = Si/(S1+S2+S3) × 100% (i represents an individual HPLC peak; S1, S2 and S3 represent peak areas of P1, P2 and P3, respectively). The avirulent strains had high values of CTI1 ranging from 63.6 to 100.0%, while the virulent strains displayed high values of CTI3 ranging from 90.2 to 100.0%. Biological inoculation studies of 68 avirulent strains revealed that the biocontrol efficacy was the best when CTI1 = 100%. The purity and genetic stability of R. solanacearum strains were confirmed in the P1 fraction of avirulent strain FJAT-1957 and P3 fraction of virulent strain FJAT-1925 after 30 generations of consecutive subculture. These results confirmed that fractioning by HPLC and their deduced CTI can be used for rapid and efficient evaluation and prediction of an isolate of R. solanacearum. To the best of our knowledge, this is the first report that HPLC fractioning can be used for rapid differentiation of virulent and avirulent strains of R. solanacearum. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. High-Performance TiO2 -Based Electron-Selective Contacts for Crystalline Silicon Solar Cells.

    PubMed

    Yang, Xinbo; Bi, Qunyu; Ali, Haider; Davis, Kristopher; Schoenfeld, Winston V; Weber, Klaus

    2016-07-01

    Thin TiO2 films are demonstrated to be an excellent electron-selective contact for crystalline silicon solar cells. An efficiency of 21.6% is achieved for crystalline silicon solar cells featuring a full-area TiO2 -based electron-selective contact.

  19. Analysis of nucleotide sugars from cell lysates by ion-pair solid-phase extraction and reversed-phase high-performance liquid chromatography.

    PubMed

    Räbinä, J; Mäki, M; Savilahti, E M; Järvinen, N; Penttilä, L; Renkonen, R

    2001-10-01

    Analysis of nucleotide sugar metabolism is essential in studying glycosylation in cells. Here we describe practical methods for both extraction of nucleotide sugars from cell lysates and for their analytical separation. Solid-phase extraction cartridges containing graphitized carbon can be used for the purification of nucleotide sugars by using triethylammonium acetate buffer as a ion-pairing reagent for decreasing retention. After that they are separated by high-performance liquid chromatography using a C18 reversed-phase column and the same ion-pairing reagent for increasing retention. These new sample preparation and analysis methods enable good separation of structurally similar sugar nucleotides, compatibility with rapid evaporative concentration, and possibility to automation. Monitoring the production of GDP-deoxyhexoses in genetically engineered yeast and native bacterial cells are described here as specific applications.

  20. Fluorinated benzothiadiazole-based conjugated polymers for high-performance polymer solar cells without any processing additives or post-treatments.

    PubMed

    Wang, Ning; Chen, Zheng; Wei, Wei; Jiang, Zhenhua

    2013-11-13

    Thanks to their many favorable advantages, polymer solar cells exhibit great potential for next-generation clean energy sources. Herein, we have successfully designed and synthesized a series of new fluorinated benzothiadiazole-based conjugated copolymers PBDT(TEH)-DT(H)BTff (P1), PBDT(TEH)-DT(EH)BTff (P2), and PBDT(HDO)-DT(H)BTff (P3). The power conversion efficiencies of 4.46, 6.20, and 8.30% were achieved for P1-, P2-, and P3-based devices within ~100 nm thickness active layers under AM 1.5G illumination without any processing additives or post-treatments, respectively. The PCE of 8.30% for P3 is the highest value for the reported traditional single-junction polymer solar cells via a simple fabrication architecture without any additives or post-treatments. In addition, it is noteworthy that P3 also allows making high efficient polymer solar cells with high PCEs of 7.27 and 6.56% under the same condition for ~200 and ~300 nm thickness active layers, respectively. Excellent photoelectric properties and good solubility make polymer P3 become an alternative material for high-performance polymer solar cells.