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1

The transparent microstrip gas counter  

NASA Astrophysics Data System (ADS)

Conventional MSGCs are made of metal electrodes that might absorb or reflect optical photons. If the electrodes are made of transparent material like ITO, we could take advantage of optical readout. A gas scintillation proportional counter made of ITO MSGC is fabricated and tested where both optical and charge signals are obtained. We have selected a multi-grid structure that can avoid charge-up problem with normal transparent glass substrate. Test results with Ar and CF4 gas mixture showed a stable gas gain of ˜2800 and ˜110 optical photons for 6 keV X-rays. Position sensing with PSPMT has successfully been demonstrated.

Takahashi, Hiroyuki; Fujita, Kaoru; Fujiwara, Takeshi; Niko, Hisako; Guerard, Bruno; Fraga, Francisco; Iyomoto, Naoko

2010-11-01

2

Transparent graphene\\/PEDOT–PSS composite films as counter electrodes of dye-sensitized solar cells  

Microsoft Academic Search

Composite films of graphene and polystyreneslufonate doped poly(3,4-ethylenedioxythiophene) (graphene\\/PEDOT–PSS) were deposited on indium tin oxide (ITO) substrates by spin coating at room temperature and applied as counter electrodes of dye-sensitized solar cells (DSSCs). A 60nm thick composite film (contained 1wt% graphene) coated ITO electrode exhibited high transmittance (>80%) at visible wavelengths and high electrocatalytic activity. The energy conversion efficiency of

Wenjing Hong; Yuxi Xu; Gewu Lu; Chun Li; Gaoquan Shi

2008-01-01

3

Flexible transparent electrode  

NASA Astrophysics Data System (ADS)

This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

2011-05-01

4

Transparent electrode for optical switch  

DOEpatents

A low pressure gas electrode utilizing ionized gas in a glow discharge regime forms a transparent electrode for electro-optical switches. The transparent electrode comprises a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the electrode is a transparent electrode. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. The plasma can be created either by the main high voltage pulser used to charge up the crystal or by auxiliary discharges or external sources of ionization. A typical configuration utilizes 10 torr argon in the discharge region adjacent to each crystal face.

Goldhar, Julius (San Ramon, CA); Henesian, Mark A. (Livermore, CA)

1986-01-01

5

Pulse-reverse electrodeposition of transparent nickel phosphide film with porous nanospheres as a cost-effective counter electrode for dye-sensitized solar cells.  

PubMed

A Ni2P nanolayer with porous nanospheres was directly coated on fluorine-doped tin oxide glass by pulse-reverse deposition as a low-cost counter electrode catalyst for dye-sensitized solar cells, and the photoelectron conversion efficiency of the cell was increased to 7.32% by using a porous nanosphere catalyst due to the significantly improved ion transport. PMID:24132176

Wu, Mao-Sung; Wu, Jia-Fang

2013-10-29

6

Carbon Nanotubes as Counter Electrodes for Gratzel Solar Cells  

NASA Astrophysics Data System (ADS)

The role of interfaces is very critical for solar cell devices which use nanostructured materials. Dye Sensitized Solar Cells (DSSC) are devices which parts are interfacial in character and physico --chemical processes occur at the interface of two distinct media. DSSC are of great interest due to combination of their high efficiency and relatively low cost. An effective counterelectrode with high electrochemical activity is an important component of DSSC to enhance its practical utility. Presently used Pt coated ITO counterelectrode can not be applied in flexible DSSC architectures, while there is a growing need for flexible anodes which are transparent and have desired interface characteristics. In this work in order to search for such materials for counter electrode in dye sensitized solar cells, newly developed strong and transparent and modified carbon nanotube sheets [1] are used in interfacial counter electrode. To increase the electrochemical activity of the anode the CNT sheets are coated with highly conductive SWCNT and compared with pure multiwall CNT sheets. We show that the transparent sheets of SWCNT/MWCNT perform as a flexible anode and as electrochemical catalyst and also can be used in tandems of dye sensitized solar cells as transparent charge recombination or interconnect layers. [1] M. Zhang, S.Fang, A.Zakhidov, S.B.Lee, A.Aliev et.al., Science, 309,(2005) 1215

Shodive, Hasan; Aliev, Ali; Zhang, Mei; Lee, Sergey; Baughman, Ray; Zakhidov, Anvar

2006-03-01

7

Transparent electrode for optical switch  

DOEpatents

The invention relates generally to optical switches and techniques for applying a voltage to an electro-optical crystal, and more particularly, to transparent electodes for an optical switch. System architectures for very large inertial confinement fusion (ICF) lasers require active optical elements with apertures on the order of one meter. Large aperture optical switches are needed for isolation of stages, switch-out from regenerative amplifier cavities and protection from target retroreflections.

Goldhar, J.; Henesian, M.A.

1984-10-19

8

Copper Nanowires as Fully Transparent Conductive Electrodes  

NASA Astrophysics Data System (ADS)

In pondering of new promising transparent conductors to replace the cost rising tin-doped indium oxide (ITO), metal nanowires have been widely concerned. Herein, we demonstrate an approach for successful synthesis of long and fine Cu nanowires (NWs) through a novel catalytic scheme involving nickel ions. Such Cu NWs in high aspect ratio (diameter of 16.2 +/- 2 nm and length up to 40 ?m) provide long distance for electron transport and, meanwhile, large space for light transmission. Transparent electrodes fabricated using the Cu NW ink achieve a low sheet resistance of 1.4 Ohm/sq at 14% transmittance and a high transparency of 93.1% at 51.5 Ohm/sq. The flexibility and stability were tested with 100-timebending by 180°and no resistance change occurred. Ohmic contact was achieved to the p- and n-GaN on blue light emitting diode chip and bright electroluminescence from the front face confirmed the excellent transparency.

Guo, Huizhang; Lin, Na; Chen, Yuanzhi; Wang, Zhenwei; Xie, Qingshui; Zheng, Tongchang; Gao, Na; Li, Shuping; Kang, Junyong; Cai, Duanjun; Peng, Dong-Liang

2013-07-01

9

Single-Walled Carbon Nanotube Transparent Electrodes  

NASA Astrophysics Data System (ADS)

Transparent conducting electrodes made from thin-film networks of single-walled carbon nanotubes (SWCNTs) are an alternative to transparent conducting oxides in many optoelectronic device applications. However, we have shown the electrical conductivity of SWCNT electrodes is limited by energy barriers at the nanotube-nanotube interfaces throughout the thin-film network [Barnes, et al., ACS Nano 2, 1968 (2008)]. We investigate various fabrication and treatment conditions to improve the electrical and optical properties of these SWCNT films. One potential pathway to improvement is to change the distribution of metallic-to-semiconducting tube types within the SWCNT network. We report the thorough characterization of SWCNT network electrodes with highly enriched metallic or semiconducting tube content through optical transmission and electrical transport measurements, as well as their performance in both organic and inorganic thin-film photovoltaic devices.

Bergeson, Jeremy D.; Blackburn, Jeffrey L.; Brown, Patrick R.; Larsen, Brian A.; Reese, Matthew O.; Barnes, Teresa M.

2010-03-01

10

Amorphous carbon as a flexible counter electrode for low cost and efficient dye sensitized solar cell  

Microsoft Academic Search

Dye sensitized solar cells (DSCs) were fabricated with carbon counter electrode deposited at low temperature. Carbon powders with an average particle size of 30–50 nm were ultrasonically dispersed in ethanol and the solution was used for spray coating onto fluorine doped tin oxide (FTO) glass substrate and also onto transparent conducting oxide coated plastic substrate at 100 °C. Thickness of the carbon

Ganapathy Veerappan; Karunagaran Bojan; Shi-Woo Rhee

11

Flexible, transparent electrodes using carbon nanotubes.  

PubMed

We prepare thin single-walled carbon nanotube networks on a transparent and flexible substrate with different densities, using a very simple spray method. We measure the electric impedance at different frequencies Z(f) in the frequency range of 40?Hz to 20?GHz using two different methods: a two-probe method in the range up to 110?MHz and a coaxial (Corbino) method in the range of 10?MHz to 20?GHz. We measure the optical absorption and electrical conductivity in order to optimize the conditions for obtaining optimum performance films with both high electrical conductivity and transparency. We observe a square resistance of 1 to 8.5?k? for samples showing 65% to 85% optical transmittance, respectively. For some applications, we need flexibility and not transparency: for this purpose, we deposit a thick film of single-walled carbon nanotubes on a flexible silicone substrate by spray method from an aqueous suspension of carbon nanotubes in a surfactant (sodium dodecyl sulphate), thereby obtaining a flexible conducting electrode showing an electrical resistance as low as 200??/sq. When stretching up to 10% and 20%, the electrical resistance increases slightly, recovering the initial value for small elongations up to 10%. We analyze the stretched and unstretched samples by Raman spectroscopy and observe that the breathing mode on the Raman spectra is highly sensitive to stretching. The high-energy Raman modes do not change, which indicates that no defects are introduced when stretching. Using this method, flexible conducting films that may be transparent are obtained just by employing a very simple spray method and can be deposited on any type or shape of surface. PMID:23074999

Ferrer-Anglada, Núria; Pérez-Puigdemont, Jordi; Figueras, Jordi; Iqbal, Muhammad Zahir; Roth, Siegmar

2012-10-17

12

Copper nanowire arrays for transparent electrodes  

NASA Astrophysics Data System (ADS)

Metallic nanowires have demonstrated high optical transmission and electrical conductivity with potential for application as transparent electrodes that may be used in flexible devices. In this paper, we systematically investigated the electrical and optical properties of 1D and 2D copper nanowire (Cu NW) arrays as a function of diameter and pitch and compared their performance to that of Cu thin films and our recent results on silver (Ag) NW arrays. Cu NWs exhibit enhanced transmission over thin films due to propagating resonance modes between NWs. For the same geometry, the transmission of Cu NW arrays is about the same as that of Ag NW arrays since the dispersion relation of propagating modes in metal nanowire arrays are independent of the metal permittivity. The sheet resistance is also comparable since the conductivity of Cu is about the same as that of Ag. Just as in Ag NWs, larger Cu NW diameters and pitches are favored for achieving higher solar transmission at a particular sheet resistance. Cu NW arrays may achieve solar transmission >90% with sheet resistances <10 ?/sq and figure of merit ?DC/?op>1000. One of the primary concerns with the use of Cu is oxidation and we also investigated the impact of a nickel (Ni) coating, which can serve as an anti-oxidation layer, on the electrical and optical properties.

Gao, Tongchuan; Leu, Paul W.

2013-08-01

13

A transparent electrode based on a metal nanotrough network  

NASA Astrophysics Data System (ADS)

Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics. Thin films of indium tin oxide--the prototypical transparent electrode material--demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications. Alternatives to indium tin oxide have recently been reported and include conducting polymers, carbon nanotubes and graphene. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity. Other examples include metal nanowire-based electrodes, which can achieve sheet resistances of less than 10? ?-1 at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ~2? ?-1 at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.

Wu, Hui; Kong, Desheng; Ruan, Zhichao; Hsu, Po-Chun; Wang, Shuang; Yu, Zongfu; Carney, Thomas J.; Hu, Liangbing; Fan, Shanhui; Cui, Yi

2013-06-01

14

Improved thermal oxidation stability of solution-processable silver nanowire transparent electrode by reduced graphene oxide.  

PubMed

Solution-processable silver nanowire-reduced graphene oxide (AgNW-rGO) hybrid transparent electrode was prepared in order to replace conventional ITO transparent electrode. AgNW-rGO hybrid transparent electrode exhibited high optical transmittance and low sheet resistance, which is comparable to ITO transparent electrode. In addition, it was found that AgNW-rGO hybrid transparent electrode exhibited highly enhanced thermal oxidation and chemical stabilities due to excellent gas-barrier property of rGO passivation layer onto AgNW film. Furthermore, the organic solar cells with AgNW-rGO hybrid transparent electrode showed good photovoltaic behavior as much as solar cells with AgNW transparent electrode. It is expected that AgNW-rGO hybrid transparent electrode can be used as a key component in various optoelectronic application such as display panels, touch screen panels, and solar cells. PMID:23206541

Ahn, Yumi; Jeong, Youngjun; Lee, Youngu

2012-12-13

15

Ag Interlayered Transparent Conducting Electrode for Photovoltaic Cells  

NASA Astrophysics Data System (ADS)

We fabricated the organic photovoltaic (OPV) cells on the transparent and low resistive multilayer electrode of a few nm Ag layer embedded Al doped zinc oxide film (AZO/Ag/AZO) on a glass. AZO and Ag consisting of the continuous multilayer were fabricated using rf magnetron at room temperature successively. AZO (45 nm)/Ag (11 nm)/AZO (45 nm) electrode shows an electrical resistivity of 6.56× 10-5 ? cm, optical transmittance of 89.3% at 550 nm and figure of merit (FOM) value of 4.94× 10-2 ?-1. An inverted structure OPV was fabricated on AZO/Ag/AZO transparent electrode in which TiOx and PEDOT:PSS were used as an electron transport and hole transport layer respectively. The OPVs showed power conversion efficiency and fill factor as high as 2.07%, 0.51 respectively.

Yang, Jeong-Do; Ok, Il-Woo; Cho, Jung-Min; Park, Dong-Hee; Shin, Won-Suk; Kim, Kyoung-Gon; Moon, Sang-Jin; Yoo, Kyung-Hwa; Choi, Won-Kook

2012-10-01

16

Novel transparent electrodes allow sustainable production of electronic devices  

SciTech Connect

A novel technique for fabricating inexpensive, transparent electrodes from common metals has been developed by engineers and scientists at Iowa State University and Ames Laboratory. They exhibit very high transparency and are very good electrical conductors. This is a combination of properties that is difficult to achieve with common materials. The most frequently used transparent electrode in today's high-technology devices (such as LCD screens) is indium tin oxide (ITO). While ITO performs well in these applications, the supply of indium is very limited. In addition, it is rapidly decreasing as consumer demand for flat-panel electronics is skyrocketing. According to a 2004 US Geological Survey report, as little as 14 years exploitation of known indium reserves remains. In addition to increasing prices, the dwindling supply of indium suggests its use is not sustainable for future generations of electronics enthusiasts. Solar cells represent another application where transparent electrodes are used. To make solar-energy collection economically feasible, all parts of solar photovoltaics must be made more efficient and cost-effective. Our novel transparent electrodes have the potential to do both. In addition, there is much interest in developing more efficient, cost-effective, and environmentally friendly lighting. Incandescent light bulbs are very inefficient, because most of their energy consumption is wasted as heat. Fluorescent lighting is much more efficient but still uses mercury, an environmental toxin. An attractive alternative is offered by LEDs, which have very high efficiencies and long lifetimes, and do not contain mercury. If made bright enough, LED use for general lighting could provide a viable alternative. We have fabricated electrodes from more commonly available materials, using a technique that is cost effective and environmentally friendly. Most of today's electronic devices are made in specialized facilities equipped with low-particle-count clean-room facilities and multimillion-dollar equipment. On the other hand, the novel process we developed uses a method that makes use of polymer molds and standard deposition techniques in an ambient laboratory environment. The final structure consists of tall ribbons of metal (standing on edge) that are so thin that they do not block light but are very good conductors. The advantage of this design is that it avoids the competition between conductivity and transparency inherent in transparent oxide electrodes. By making the structure taller, conductivity can be increased without impacting transparency. We have measured both electrical conductivity and transparency for these structures. We performed two-wire electrical measurements to quantify the structures resistance using metal contacts deposited on each end. The total sample area was 4 x 4mm{sup 2}. We measured a resistance of structures with 40nm gold sidewalls of 7.3{Omega}, which is lower than that of ITO glass (which has a sheet resistance around 10O/square). We investigated the structures optical properties based on both specular- and total-transmission measurements. Specular transmission is measured by collecting the transmitted light at normal incidence, while total transmission is obtained by collecting transmitted light at normal incidence and diffracted light using an integrating sphere. Figure 3 shows the total transmission of a grating with 40nm gold or silver sidewalls on a glass substrate compared to that of ITO. Additionally, the transparency changes very little within 30{sup o} off normal incidence. This high visible-light transmission of our metal-patterned structures is very promising for their application as transparent electrodes, because most visible light was allowed to propagate through the patterned metallic/polymeric structures. Researchers in our group continue to refine the fabrication methods and are investigating methods to make large-scale structures for use in a variety of applications that require both transparency and high electrical conductivity. We are also applying these fab

Constant, Kristen

2010-12-27

17

Transparent composite electrode for high-efficiency polymer LEDs  

NASA Astrophysics Data System (ADS)

Polymer composite electrodes based on silver nanowires or carbon nanotubes have been prepared with transparency and surface conductivity approaching those of ITO/glass and better than ITO/PET. The conductive surface has an average roughness less than 10 nm, better than ITO/glass. Depending on the polymer matrix selected, the composite electrodes can be made rigid, flexible like polycarbonate, or stretchable like a rubber. Various polymer light emitting diodes,light emitting electrochemical cells and polymer solar cells have been fabricated using the composite electrode as anode, exhibiting electroluminescent efficiencies generally higher than control devices fabricated on ITO/glass. These polymer light emitting devices are all highly flexible and can be bent to less than 3 mm radius without loss of performance. With further modification of the composite electrodes, we have also demonstrated stretchable OLEDs wherein the emissive area can be elongated by as much as 50%.

Li, Lu; Yu, Zhibin; Liang, Jiajie; Chang, Chia-Hao; Hu, Weili; Pei, Qibing

2012-09-01

18

Graphene-ferroelectric hybrid structure for flexible transparent electrodes.  

PubMed

Graphene has exceptional optical, mechanical, and electrical properties, making it an emerging material for novel optoelectronics, photonics, and flexible transparent electrode applications. However, the relatively high sheet resistance of graphene is a major constraint for many of these applications. Here we propose a new approach to achieve low sheet resistance in large-scale CVD monolayer graphene using nonvolatile ferroelectric polymer gating. In this hybrid structure, large-scale graphene is heavily doped up to 3 × 10(13) cm(-2) by nonvolatile ferroelectric dipoles, yielding a low sheet resistance of 120 ?/? at ambient conditions. The graphene-ferroelectric transparent conductors (GFeTCs) exhibit more than 95% transmittance from the visible to the near-infrared range owing to the highly transparent nature of the ferroelectric polymer. Together with its excellent mechanical flexibility, chemical inertness, and the simple fabrication process of ferroelectric polymers, the proposed GFeTCs represent a new route toward large-scale graphene-based transparent electrodes and optoelectronics. PMID:22524641

Ni, Guang-Xin; Zheng, Yi; Bae, Sukang; Tan, Chin Yaw; Kahya, Orhan; Wu, Jing; Hong, Byung Hee; Yao, Kui; Özyilmaz, Barbaros

2012-04-27

19

Comparison of transparent conducting electrodes on mercuric iodide photocells  

SciTech Connect

Three materials have been developed and tested which are suitable as transparent conducting electrodes on mercuric iodide; aqueous ionic contacts of NAC/ell/ and LiC/ell/, polyvinyl alcohol/phosphoric acid, and indium--tin--oxide (ITO). Polyvinyl alcohol/phosphoric acid is a conducting polymer and ITO is a wide band gap semiconductor. Photocell dimensions were in the range of 0.5 to 3.8 cm diam by about 1 mm thick. Photocells with these electrodes were evaluated for their spectral response in the range of 300 to 650 nm, response uniformity over the electrode activities area, leakage current and reliability. All units showed better than 75% quantum efficiency in the range 350 to 550 nm. Photodetector leakage currents ranged from 25 to 200 pA and have shown long term stability up to 1 year.

Cheng, A.Y.; Markakis, J.M.

1987-01-01

20

Rational design of hybrid graphene films for high-performance transparent electrodes.  

PubMed

Transparent, flexible conducting films were fabricated by using a metallic grid and graphene hybrid film. Transparent electrodes using the hybrid film and transparent substrate such as glass or polyethylene terephthalate (PET) films were assembled. The sheet resistance of the fabricated transparent electrodes was as low as 3 ?/? with the transmittance at ?80%. At 90% transmittance, the sheet resistance was ?20 ?/?. Both values are among the highest for transparent electrode materials to date. The materials used for the new hybrid electrode are earth-abundant stable elements, which increase their potential usefulness for replacement of indium tin oxide (ITO) in many applications. PMID:21774533

Zhu, Yu; Sun, Zhengzong; Yan, Zheng; Jin, Zhong; Tour, James M

2011-07-29

21

Fissile material transparency technology demonstration : neutron multiplicity counter /  

SciTech Connect

The Fissile Material Transparency Technology Demonstration occurred at Los Alamos National Laboratory, August 14-17, 2000. The demonstration showed the determination of six attributes (Pu presence, Pu isotopics, Pu mass, absence of oxide, symmetry, and age) on unclassified plutonium samples and a US nuclear weapons component. The demonstrations showed that a six-attribute measurement system with information barrier could be fabricated and was capable of protecting classified information. In order to measure the six attributes, a high-resolution gamma-ray spectroscopy system and neutron multiplicity system were developed. This talk discusses the neutron multiplicity system, along with data taken on the unclassified samples.

Bourret, S. C.; Harker, W. C. (William C.); Hypes, P. A. (Philip A.); Langner, D. C. (Diana C.); Salazar, S. D. (Steven D.); Siebelist, R. (Richard); Smith, M. K. (Morag K.); Sweet, M. R. (Martin R.); Mayo, D. R. (Douglas R.)

2001-01-01

22

Effect of Porous Counter Electrode with Highly Conductive Layer on Dye-Sensitized Solar Cells  

NASA Astrophysics Data System (ADS)

A Pt/porous titanium (Ti)/dense Ti/aluminum (Al)/glass composite counter electrode for a dye-sensitized solar cell (DSC) was fabricated and characterized. The introduction of a highly conductive Al film drastically reduced the sheet resistance of the counter electrode to improve the short circuit current and fill factor of the DSC. Porous and dense Ti layers were deposited by the DC magnetron sputtering process. The dense Ti layer protected the Al film from dissolution in the electrolyte solution to stabilize the composite counter electrode. The porous Ti layer with a larger electrochemical active area at the electrolyte/counter electrode interface mainly improved the short circuit current of the DSC. The results indicate the importance of the introduction of porous materials with highly conductive films into the counter electrode of a DSC and the suitability of composite materials of Al and Ti for the counter electrode.

Rahman, Mohammad Maksudur; Kojima, Ryota; Fihry, Mehdi El Fassy; Tadaki, Daisuke; Ma, Teng; Kimura, Yasuo; Niwano, Michio

2011-08-01

23

Anthocyanin-sensitized solar cells using carbon nanotube films as counter electrodes  

NASA Astrophysics Data System (ADS)

Carbon nanotube (CNT) films have been used as counter electrodes in natural dye-sensitized (anthocyanin-sensitized) solar cells to improve the cell performance. Compared with conventional cells using natural dye electrolytes and platinum as the counter electrodes, cells with a single-walled nanotube (SWNT) film counter electrode show comparable conversion efficiency, which is attributed to the increase in short circuit current density due to the high conductivity of the SWNT film.

Zhu, Hongwei; Zeng, Haifeng; Subramanian, Venkatachalam; Masarapu, Charan; Hung, Kai-Hsuan; Wei, Bingqing

2008-11-01

24

Electroluminescent Device Comprising a Transparent Structured Electrode Layer Made From a Conductive Polymer  

Microsoft Academic Search

An electroluminescent (EL) device is (1) composed of polymeric LEDs comprising an active layer (7) of a conjugated polymer and a transparent polymeric electrode layer (5) having electroconductive areas (51) as electrodes. Like the active layer (7), the electrode layer (5) can be manufactured in a simple manner by spin coating. The electrode layer (5) is structured into conductive electrodes

Aemilianus G. J. Staring; David Braun

1998-01-01

25

Electroluminescent Device Comprising a Transparent Structured Electrode Layer Made From a Conductive Polymer  

Microsoft Academic Search

A description is given of an electroluminescent (EL) device (1) composed of polymeric LEDs comprising an active layer (7) of a conjugated polymer and a transparent polymeric electrode layer (5) having electroconductive areas (51) as electrodes. Like the active layer (7), the electrode layer (5) can be manufactured in a simple manner by spin coating. The electrode layer (5) is

Aemilianus G. J. Staring; David Braun

1999-01-01

26

Rational screening low-cost counter electrodes for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

Dye-sensitized solar cells have attracted intense research attention owing to their ease of fabrication, cost-effectiveness and high efficiency in converting solar energy. Noble platinum is generally used as catalytic counter electrode for redox mediators in electrolyte solution. Unfortunately, platinum is expensive and non-sustainable for long-term applications. Therefore, researchers are facing with the challenge of developing low-cost and earth-abundant alternatives. So far, rational screening of non-platinum counter electrodes has been hamstrung by the lack of understanding about the electrocatalytic process of redox mediators on various counter electrodes. Here, using first-principle quantum chemical calculations, we studied the electrocatalytic process of redox mediators and predicted electrocatalytic activity of potential semiconductor counter electrodes. On the basis of theoretical predictions, we successfully used rust (?-Fe2O3) as a new counter electrode catalyst, which demonstrates promising electrocatalytic activity towards triiodide reduction at a rate comparable to platinum.

Hou, Yu; Wang, Dong; Yang, Xiao Hua; Fang, Wen Qi; Zhang, Bo; Wang, Hai Feng; Lu, Guan Zhong; Hu, P.; Zhao, Hui Jun; Yang, Hua Gui

2013-03-01

27

Transparent electrodes fabricated via the self-assembly of silver nanowires using a bubble template.  

PubMed

To shore up the demand of transparent electrodes for wide applications such as organic light emitting diodes and solar cells, transparent electrodes are required as an alternative for indium tin oxide electrodes. Herein the self-assembly method with a bubble template paves the way for cost-effective fabrication of transparent electrodes with high conductivity and transparency using self-assembly of silver nanowires (AgNWs) in a bubble template. AgNWs were first dispersed in water that was bubbled with a surfactant and a thickening agent. Furthermore, these AgNWs were assembled by lining along the bubble ridges. When the bubbles containing the AgNWs were sandwiched between two glass substrates, the bubble ridges including the AgNWs formed continuous polygonal structures. Mesh structures were formed on both glass substrates after air-drying. The mesh structures evolved into mesh transparent electrodes following heat-treatment. The AgNW mesh structure exhibited a low sheet resistance of 6.2 ?/square with a transparency of 84% after heat treatment at 200 °C for 20 min. The performance is higher than that of transparent electrodes with random networks of AgNWs. Furthermore, the conductivity and transparency of the mesh transparent electrodes can be adjusted by changing the amount of the AgNW suspension and the space between the two glass substrates. PMID:22642559

Tokuno, Takehiro; Nogi, Masaya; Jiu, Jinting; Sugahara, Tohru; Suganuma, Katsuaki

2012-06-11

28

Hybrid transparent electrodes of silver nanowires and carbon nanotubes: a low-temperature solution process  

NASA Astrophysics Data System (ADS)

Hybrid transparent electrodes with silver nanowires (AgNWs) and single-walled carbon nanotubes (SWCNTs) were fabricated on plastic films by a low-temperature solution process. The hybrid transparent electrodes exhibited a sheet resistance of 29.2 ?/sq with a transparency of 80% when 6 wt.% of SWCNTs was mixed with AgNWs. This sheet resistance was less than one-fourth that of the AgNW transparent electrodes that were prepared using the same method. This reduction in sheet resistance is because the SWCNTs formed bridges between the AgNWs, thus, resulting in high conductivity of the hybrid transparent electrodes. The hybrid electrodes formed on plastic films exhibited high conductivity as well as excellent stability in sheet resistance when tested using a repeated bending test. PACS: 62.23.Hj; 61.48.De; 81.15.-z.

Tokuno, Takehiro; Nogi, Masaya; Jiu, Jinting; Suganuma, Katsuaki

2012-05-01

29

Performance enhancement of metal nanowire transparent conducting electrodes by mesoscale metal wires  

NASA Astrophysics Data System (ADS)

For transparent conducting electrodes in optoelectronic devices, electrical sheet resistance and optical transmittance are two of the main criteria. Recently, metal nanowires have been demonstrated to be a promising type of transparent conducting electrode because of low sheet resistance and high transmittance. Here we incorporate a mesoscale metal wire (1-5??m in diameter) into metal nanowire transparent conducting electrodes and demonstrate at least a one order of magnitude reduction in sheet resistance at a given transmittance. We realize experimentally a hybrid of mesoscale and nanoscale metal nanowires with high performance, including a sheet resistance of 0.36???sq-1 and transmittance of 92%. In addition, the mesoscale metal wires are applied to a wide range of transparent conducting electrodes including conducting polymers and oxides with improvement up to several orders of magnitude. The metal mesowires can be synthesized by electrospinning methods and their general applicability opens up opportunities for many transparent conducting electrode applications.

Hsu, Po-Chun; Wang, Shuang; Wu, Hui; Narasimhan, Vijay K.; Kong, Desheng; Ryoung Lee, Hye; Cui, Yi

2013-09-01

30

Performance enhancement of metal nanowire transparent conducting electrodes by mesoscale metal wires.  

PubMed

For transparent conducting electrodes in optoelectronic devices, electrical sheet resistance and optical transmittance are two of the main criteria. Recently, metal nanowires have been demonstrated to be a promising type of transparent conducting electrode because of low sheet resistance and high transmittance. Here we incorporate a mesoscale metal wire (1-5??m in diameter) into metal nanowire transparent conducting electrodes and demonstrate at least a one order of magnitude reduction in sheet resistance at a given transmittance. We realize experimentally a hybrid of mesoscale and nanoscale metal nanowires with high performance, including a sheet resistance of 0.36???sq(-1) and transmittance of 92%. In addition, the mesoscale metal wires are applied to a wide range of transparent conducting electrodes including conducting polymers and oxides with improvement up to several orders of magnitude. The metal mesowires can be synthesized by electrospinning methods and their general applicability opens up opportunities for many transparent conducting electrode applications. PMID:24065116

Hsu, Po-Chun; Wang, Shuang; Wu, Hui; Narasimhan, Vijay K; Kong, Desheng; Ryoung Lee, Hye; Cui, Yi

2013-09-25

31

Nickel phosphide-embedded graphene as counter electrode for dye-sensitized solar cells.  

PubMed

Nickel phosphide-embedded graphene, prepared by the hydrothermal reaction of red phosphorus, nickel chloride, and graphene oxide in a mixture of ethylene glycol-water, is investigated as the counter electrode of DSSCs. It is demonstrated that the DSSC with the nickel phosphide-embedded graphene as the new counter electrode presents an excellent performance competing with that of the Pt electrode. PMID:22160103

Dou, Y Y; Li, G R; Song, J; Gao, X P

2011-12-12

32

Past achievements and future challenges in the development of optically transparent electrodes  

NASA Astrophysics Data System (ADS)

Transparent conductive electrodes play important roles in information and energy technologies. These materials, particularly transparent conductive oxides, are widely used as transparent electrodes across technical fields such as low-emissivity coatings, flat-panel displays, thin-film solar cells and organic light-emitting diodes. This Review begins by summarizing the properties and applications of transparent conductive oxides such as In2O3, SnO2, ZnO and TiO2. Owing to the increasing demand for raw materials -- especially indium -- scientists are currently searching for alternatives to indium tin oxide. Carbon nanotube and metal nanowire networks, as well as regular metal grids, have been investigated for use as transparent conductive electrodes. This Review compares these materials and the recently 'rediscovered' graphene with today's established transparent conductive oxides.

Ellmer, Klaus

2012-12-01

33

Polymer-assisted direct deposition of uniform carbon nanotube bundle networks for high performance transparent electrodes.  

PubMed

Flexible transparent electrodes are crucial for touch screen, flat panel display, and solar cell technologies. While carbon nanotube network electrodes show promise, characteristically poor dispersion properties have limited their practicality. We report that addition of small amounts of conjugated polymer to nanotube dispersions enables straightforward fabrication of uniform network electrodes by spin-coating and simultaneous tuning of parameters such as bundle size and density. After treatment in thionyl chloride, electrodes have sheet resistances competitive with other reported carbon nanotube based transparent electrodes to date. PMID:19422197

Hellstrom, Sondra L; Lee, Hang Woo; Bao, Zhenan

2009-06-23

34

Low-Cost Flexible Nano-Sulfide/Carbon Composite Counter Electrode for Quantum-Dot-Sensitized Solar Cell  

PubMed Central

Cu2S nanocrystal particles were in situ deposited on graphite paper to prepare nano-sulfide/carbon composite counter electrode for CdS/CdSe quantum-dot-sensitized solar cell (QDSC). By optimization of deposition time, photovoltaic conversion efficiency up to 3.08% was obtained. In the meantime, this composite counter electrode was superior to the commonly used Pt, Au and carbon counter electrodes. Electrochemical impedance spectra further confirmed that low charge transfer resistance at counter electrode/electrolyte interface was responsible for this, implied the potential application of this composite counter electrode in high-efficiency QDSC.

2010-01-01

35

Carbon nanotube counter electrode for high-efficient fibrous dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

High-efficient fibrous dye-sensitized solar cell with carbon nanotube (CNT) thin films as counter electrodes has been reported. The CNT films were fabricated by coating CNT paste or spraying CNT suspension solution on Ti wires. A fluorine tin oxide-coated CNT underlayer was used to improve the adherence of the CNT layer on Ti substrate for sprayed samples. The charge transfer catalytic behavior of fibrous CNT/Ti counter electrodes to the iodide/triiodide redox pair was carefully studied by electrochemical impedance and current-voltage measurement. The catalytic activity can be enhanced by increasing the amount of CNT loading on substrate. Both the efficiencies of fibrous dye-sensitized solar cells using paste coated and sprayed CNT films as counter electrodes are comparative to that using Pt wires, indicating the feasibility of CNT/Ti wires as fibrous counter electrode for superseding Pt wires.

Huang, Shuqing; Sun, Huicheng; Huang, Xiaoming; Zhang, Quanxin; Li, Dongmei; Luo, Yanhong; Meng, Qingbo

2012-04-01

36

Carbon nanotube counter electrode for high-efficient fibrous dye-sensitized solar cells  

PubMed Central

High-efficient fibrous dye-sensitized solar cell with carbon nanotube (CNT) thin films as counter electrodes has been reported. The CNT films were fabricated by coating CNT paste or spraying CNT suspension solution on Ti wires. A fluorine tin oxide-coated CNT underlayer was used to improve the adherence of the CNT layer on Ti substrate for sprayed samples. The charge transfer catalytic behavior of fibrous CNT/Ti counter electrodes to the iodide/triiodide redox pair was carefully studied by electrochemical impedance and current-voltage measurement. The catalytic activity can be enhanced by increasing the amount of CNT loading on substrate. Both the efficiencies of fibrous dye-sensitized solar cells using paste coated and sprayed CNT films as counter electrodes are comparative to that using Pt wires, indicating the feasibility of CNT/Ti wires as fibrous counter electrode for superseding Pt wires.

2012-01-01

37

Quasi-solid-state dye-sensitized solar cells: Pt and PEDOT:PSS counter electrodes applied to gel electrolyte assemblies  

Microsoft Academic Search

In this paper we present an attempt to substitute liquid electrolyte (LC) dye-sensitized solar cells (DSSCs) by quasi-solid-state constructions (SC) for semi-transparency application adopting organic\\/inorganic gels in combination with standard (Pt based) and alternative (PEDOT:PSS based) counter electrodes. Gel polymer electrolytes are prepared by incorporating a liquid electrolyte into a polymer matrix such as polymethyl-methacrylate (PMMA) using propylene carbonate (PC)

Matteo Biancardo; Keld West; Frederik C. Krebs

2007-01-01

38

Solution-processed metallic conducting polymer films as transparent electrode of optoelectronic devices.  

PubMed

The conductivity of PEDOT:PSS films was significantly enhanced from 0.3 S cm(-1) to 3065 S cm(-1) through a treatment with dilute sulfuric acids. PEDOT:PSS films with a sheet resistance of 39 ? sq(-1) and transparency of around 80% at 550 nm are obtained. These PEDOT:PSS films with conductivity and transparency comparable to ITO can replace ITO as the transparent electrode of optoelectronic devices. PMID:22488584

Xia, Yijie; Sun, Kuan; Ouyang, Jianyong

2012-04-10

39

Hierarchical micro/nano-structured cobalt sulfide spindles as low-cost counter electrodes for dye-sensitized solar cells.  

PubMed

Hierarchical micro/nano-structured cobalt sulfide spindles are synthesized via a hydrothermal method and investigated as counter electrodes for dye-sensitized solar cells (DSCs). It is demonstrated that DSCs with hierarchical cobalt sulfide spindle electrodes show an excellent photovoltaic performance competing with that of a device with a Pt counter electrode. PMID:23873051

Wang, Guiqiang; Zhuo, Shuping

2013-07-19

40

Solar cells incorporating transparent electrodes comprising hazy zinc oxide  

SciTech Connect

This patent describes a photovoltaic device. It comprises a semiconductor layer comprising a compound semiconductor selected from the group consisting of II/VI, III/V, I/III/VI, and II/IV/V compounds; and a transparent conductor layer in contact with the semiconductor layer, wherein the transparent conductor layer comprises hazy ZnO.

Pier, D.N.; Gay, C.F.; Wieting, R.D.; Langeberg, H.J.

1992-01-07

41

Preparation and Characterization of CNT/TiO2 Based Transparent Fiber Electrodes  

NASA Astrophysics Data System (ADS)

In the present work, it is shown that carbon nanotube-doped transition metal oxides are potential candidates for use as ceramic transparent electrode materials. Electrodes in shape of fibers are obtained via inexpensive and low temperature sol-gel method. Fiber electrodes are characterised by SEM-FIB and rheological analizes. Due to extraordinary electrical and optical properties of CNT-s and good chemical and physical stability of metal oxide ceramics, resulting composites could be an interesting subject for industry.

Paalo, M.; Tätte, T.; Hussainov, M.; Hanschmidt, K.; Lobjakas, M.; Lõhmus, A.; Mäeorg, U.; Kink, I.

2012-08-01

42

Silicon Pedot-Pss Nanocomposite as AN Efficient Counter Electrode for Dye-Sensitized Solar Cells  

NASA Astrophysics Data System (ADS)

A novel inorganic/organic nanocomposite film composed of Si nanoparticles (NPs) and poly-(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) is obtained from a simple mechanical mixture of Si NPs powder and aqueous PEDOT-PSS solution. Employing this composite film as a counter electrode, dye-sensitized solar cell (DSSC) exhibits an efficiency of 5.7% and a fill factor of 0.51, which are much higher than these of DSSC using pristine PEDOT-PSS electrode (2.9% and 0.25, respectively). The improvements in the photovoltaic performance of the former are primarily derived from improved electrocatalytic performance of the electrode, as evidenced by electrochemical measurements, the composite electrode has lower impedance and higher electrocatalytic activity when in comparison with pristine PEDOT-PSS electrode. These improvements are primarily deriving from the increased electrochemical surface by the addition of Si NPs. The characteristics of Si NPs/PEDOT-PSS composite counter electrode reveal its potential for the use of low-cost and stable Pt-free counter electrode materials. In addition, the results achieved in this work also provide a facile and efficient approach to improve the photovoltaic performance of DSSCs using PEDOT-PSS electrodes.

Song, Dandan; Li, Meicheng; Bai, Fan; Li, Yingfeng; Jiang, Yongjian; Jiang, Bing

2013-08-01

43

Fabrication and characterization of carbon-based counter electrodes prepared by electrophoretic deposition for dye-sensitized solar cells  

PubMed Central

Three different carbon-based counter electrodes are investigated in light of catalytic activities such as electrochemical frequencies and interface impedances. We fabricated carbon-based counter electrodes of dye-sensitized solar cells [DSSCs] using graphene, single-walled carbon nanotubes [SWNTs], and graphene-SWNT composites by electrophoretic deposition method. We observed the optical and electrochemical properties of the carbon-based counter electrodes. The DSSC with the graphene-deposited counter electrode demonstrated the best conversion efficiency of 5.87% under AM 1.5 and 1 sun condition. It could be utilized for a low-cost and high-throughput process for DSSCs.

2012-01-01

44

Different hierarchical nanostructured carbons as counter electrodes for CdS quantum dot solar cells.  

PubMed

CdS quantum dot sensitized solar cells based on TiO(2) photoanode and nanostructured carbon as well as Pt as counter electrodes using iodide/triiodide and polysulfide electrolytes were fabricated to improve the efficiency and reduce the cost of solar cells. Compared with conventional Pt (? = 1.05%) and CMK-3 (? = 0.67%) counter electrodes, hollow core-mesoporous shell carbon (HCMSC) counter electrode using polysulfide electrolyte exhibits much larger incident photon to current conversion efficiency (IPCE = 27%), photocurrent density (J(sc) = 4.31 mA.cm(-2)) and power conversion efficiency (? = 1.08%), which is basically due to superb structural characters of HCMSC such as large specific surface area, high mesoporous volume, and 3D interconnected well-developed hierarchical porosity network, which facilitate fast mass transfer with less resistance and enable HCMSC to have highly enhanced catalytic activity toward the reduction of electrolyte shuttle. PMID:22132833

Paul, Gouri Sankar; Kim, Jung Ho; Kim, Min-Sik; Do, Kwangseok; Ko, Jaejung; Yu, Jong-Sung

2011-12-16

45

Transparent conductive graphene electrode in GaN-based ultra-violet light emitting diodes.  

PubMed

We report a graphene-based transparent conductive electrode for use in ultraviolet (UV) GaN light emitting diodes (LEDs). A few-layer graphene (FLG) layer was mechanically deposited. UV light at a peak wavelength of 368 nm was successfully emitted by the FLG layer as transparent contact to p-GaN. The emission of UV light through the thin graphene layer was brighter than through the thick graphene layer. The thickness of the graphene layer was characterized by micro-Raman spectroscopy. Our results indicate that this novel graphene-based transparent conductive electrode holds great promise for use in UV optoelectronics for which conventional ITO is less transparent than graphene. PMID:21164643

Kim, Byung-Jae; Mastro, Michael A; Hite, Jennifer; Eddy, Charles R; Kim, Jihyun

2010-10-25

46

Molecular-Beam Epitaxial Growth of a Far-Infrared Transparent Electrode for Extrinsic Germanium Photoconductors  

NASA Astrophysics Data System (ADS)

We have evaluated the optical and electrical properties of a far-infrared (IR) transparent electrode for extrinsic germanium (Ge) photoconductors at 4 K, which was fabricated by molecular beam epitaxy (MBE). As a far-IR transparent electrode, an aluminum (Al)-doped Ge layer is formed at well-optimized doping concentration and layer thickness in terms of the three requirements: high far-IR transmittance, low-resistivity, and excellent ohmic contact. The Al-doped Ge layer has the far-IR transmittance of >95% within the wavelength range of 40--200 ?m, while low-resistivity (˜5 ? cm) and ohmic contact are ensured at 4 K. We demonstrate the applicability of the MBE technology in fabricating the far-IR transparent electrode satisfying the above requirements.

Suzuki, Toyoaki; Wada, Takehiko; Hirose, Kazuyuki; Makitsubo, Hironobu; Kaneda, Hidehiro

2012-08-01

47

30 inch Roll-Based Production of High-Quality Graphene Films for Flexible Transparent Electrodes  

Microsoft Academic Search

We report that 30-inch scale multiple roll-to-roll transfer and wet chemical doping considerably enhance the electrical properties of the graphene films grown on roll-type Cu substrates by chemical vapor deposition. The resulting graphene films shows a sheet resistance as low as ~30 Ohm\\/sq at ~90 % transparency which is superior to commercial transparent electrodes such as indium tin oxides (ITO).

Sukang Bae; Hyeong Keun Kim; Youngbin Lee; Xianfang Xu; Jae-Sung Park; Yi Zheng; Jayakumar Balakrishnan; Danho Im; Tian Lei; Young Il Song; Young Jin Kim; Kwang S. Kim; Barbaros Özyilmaz; Jong-Hyun Ahn; Byung Hee Hong; Sumio Iijima

2009-01-01

48

Sub-micrometer-sized graphite as a conducting and catalytic counter electrode for dye-sensitized solar cells.  

PubMed

Sub-micrometer-sized colloidal graphite (CG) was tested as a conducting electrode to replace transparent conducting oxide (TCO) electrodes and as a catalytic material to replace platinum (Pt) for I(3)(-) reduction in dye-sensitized solar cell (DSSC). CG paste was used to make a film via the doctor-blade process. The 9 ?m thick CG film showed a lower resistivity (7 ?/?) than the widely used fluorine-doped tin oxide TCO (8-15 ?/?). The catalytic activity of this graphite film was measured and compared with the corresponding properties of Pt. Cyclic voltammetry and electrochemical impedance spectroscopy studies clearly showed a decrease in the charge transfer resistance with the increase in the thickness of the graphite layer from 3 to 9 ?m. Under 1 sun illumination (100 mW cm(-2), AM 1.5), DSSCs with submicrometer-sized graphite as a catalyst on fluorine-doped tin oxide TCO showed an energy conversion efficiency greater than 6.0%, comparable to the conversion efficiency of Pt. DSSCs with a graphite counter electrode (CE) on TCO-free bare glass showed an energy conversion efficiency greater than 5.0%, which demonstrated that the graphite layer could be used both as a conducting layer and as a catalytic layer. PMID:21351744

Veerappan, Ganapathy; Bojan, Karunagaran; Rhee, Shi-Woo

2011-02-25

49

Ultrathin optically transparent carbon electrodes produced from layers of adsorbed proteins.  

PubMed

This work describes a simple, versatile, and inexpensive procedure to prepare optically transparent carbon electrodes, using proteins as precursors. Upon adsorption, the protein-coated substrates were pyrolyzed under reductive conditions (5% H2) to form ultrathin, conductive electrodes. Because proteins spontaneously adsorb to interfaces forming uniform layers, the proposed method does not require a precise control of the preparation conditions, specialized instrumentation, or expensive precursors. The resulting electrodes were characterized by a combination of electrochemical, optical, and spectroscopic means. As a proof-of-concept, the optically transparent electrodes were also used as substrate for the development of an electrochemical glucose biosensor. The proposed films represent a convenient alternative to more sophisticated, and less available, carbon-based nanomaterials. Furthermore, these films could be formed on a variety of substrates, without classical limitations of size or shape. PMID:23421732

Alharthi, Sarah A; Benavidez, Tomás E; Garcia, Carlos D

2013-03-04

50

Graphene transparent and conductive electrode for light harvesting solar cells  

Microsoft Academic Search

Transparent and conductive coatings were achieved on glass by dissolving graphene oxide into dionized water followed by spray-coating on preheated substrate, chemical and thermal reduction. SEM shows the spray-coating graphene oxide coatings and the reduced graphene oxide coatings are uniform. No obvious aggregation was observed. UV-vis transmission spectra shows 65% transmittance at 550 nm of the graphene coatings with 15

Wei Zhou; Amare Benor Belay; Kris Davis; Rodica Khugler; Nicoleta Sorloaica-Hickman

2011-01-01

51

Characterization of a tantalum capacitor fabricated with a conducting polypyrrole as a counter electrode  

Microsoft Academic Search

A tantalum solid electrolytic capacitor, using a conducting polypyrrole composite as a counter electrode, has been investigated concerning the temperature dependence of the series resistance and leakage current. The resistance of the capacitor changes along the curve expected from the variable-range-hopping (VRH) process. The conductivity of polypyrrole in the capacitor, estimated from the known VRH parameter of the polymer, coincides

M. Satoh; H. Ishikawa; K. Amano; E. Hasegawa; K. Yoshino

1995-01-01

52

Flexible organic light-emitting diodes with transparent carbon nanotube electrodes: problems and solutions  

Microsoft Academic Search

We study in detail here the application of transparent, conductive carbon single-wall nanotube (SWNT) networks as electrodes in flexible organic light-emitting diodes (FOLEDs). Overall comparisons of these networks to the commonly used electrodes poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and indium tin oxide (ITO) are made, and SWNT networks are shown to have excellent optical and superior mechanical properties. The effects of protruding

Liangbing Hu; Jianfeng Li; Jun Liu; George Grüner; Tobin Marks

2010-01-01

53

Toward Low-Cost, High-Efficiency, and Scalable Organic Solar Cells with Transparent Metal Electrode and Improved Domain Morphology  

Microsoft Academic Search

We review our recent progress toward realizing future low-cost, high-efficiency, and scalable organic solar cells (OSCs). First, we show that the transparent electrodes based on metallic nanostructure is a strong candidate as a replacement of conventional indium tin oxide (ITO) electrode due to their superior properties, such as high optical transparency, good electrical conductivity, and mechanical flexibility, and the versatility

Myung-Gyu Kang; Hui Joon Park; Se Hyun Ahn; Ting Xu; L. Jay Guo

2010-01-01

54

Flexible, transparent single-walled carbon nanotube transistors with graphene electrodes  

Microsoft Academic Search

This paper reports a mechanically flexible, transparent thin film transistor that uses graphene as a conducting electrode and single-walled carbon nanotubes (SWNTs) as a semiconducting channel. These SWNTs and graphene films were printed on flexible plastic substrates using a printing method. The resulting devices exhibited a mobility of ~ 2 cm2 V - 1 s - 1, On\\/Off ratio of

Sukjae Jang; Houk Jang; Youngbin Lee; Daewoo Suh; Seunghyun Baik; Byung Hee Hong; Jong-Hyun Ahn

2010-01-01

55

Few layers of graphene as transparent electrode from botanical derivative camphor  

Microsoft Academic Search

Here, we report synthesis of large area graphene sheets by control pyrolysis of solid botanical derivative camphor (C10H16O) and fabrication of transparent electrodes. Raman study shows highly ordered graphene sheet with minimum defects. Second order Raman spectrum shows that graphene layers are more than single layer and can be controlled with amount of camphor pyrolyzed. Transmission electron microscopic images show

Golap Kalita; Matsushima Masahiro; Hideo Uchida; Koichi Wakita; Masayoshi Umeno

2010-01-01

56

Highly transparent polymer light-emitting diode using modified aluminum-doped zinc oxide top electrode  

NASA Astrophysics Data System (ADS)

We report a novel approach that leads to a significant improvement in the performance of transparent polymer light-emitting diodes (TPLEDs). By introducing a solution-based titanium oxide (TiOx) layer, we have demonstrated that the device performance of TPLEDs using aluminum-doped zinc oxide (AZO) top electrodes is enhanced. The TiOx layer lowers the energy barrier between the luminescent polymer and the AZO top electrode by modifying the WF of the top AZO electrodes. Moreover, the TiOx layer prevents the damage caused by UV radiation and by highly energetic ions generated during the AZO sputtering.

Heum Park, Sung; Hoon Lee, Byoung; Moon Shin, Jong; Jeong, Se-Young; Song, Suhee; Suh, Hongsuk; Lee, Kwanghee

2012-03-01

57

Flexible OLED with Transparent Multiwall Carbon Nanotubes Electrodes  

NASA Astrophysics Data System (ADS)

We have demonstrated earlier, that transparent carbon nanotube (T-CNT) sheets, prepared by dry spinning of CVD grown multiwall nanotube forests can be used as hole injectors in bright OLEDs with Alq3 as emissive layers [1]. Now we demonstrate here that advantages of mechanically strong, elastomeric T-CNT over traditional ITO can be further favorably used in flexible OLEDs (based on Alq3 emitter) fabricated on mylar or PET substrates. The high work function of T-CNT sheet (˜5.2 eV) and the geometry of sharp tips allows to achieve tunneling charge injection regime at relatively low voltages, which allows to achieve higher hole injection current densities. Moreover we demonstrate, that the use of low quality ITO on PET, combined with T-CNT as tunneling hole injector may have advantages for large area OLED/PLEDs. [1] M. Zhang, S. Fang, A. Zakhidov, S. B. Lee, A. Aliev, R.H. Baughman, Strong, Transparent, Multifunctional, Carbon Nanotube Sheets, Science, 309,(2005) 1215

Ovalle Robles, Raquel; Williams, Christopher; Zhang, Mei; Fang, Shaoli; Lee, Sergey; Ferraris, John; Baughman, Ray; Zakhidov, Anvar

2007-03-01

58

High figure-of-merit ultrathin metal transparent electrodes incorporating a conductive grid  

SciTech Connect

It is known that ultrathin (<10 nm) metal films (UTMFs) can achieve high level of optical transparency at the expense of the electrical sheet resistance. In this letter, we propose a design, the incorporation of an ad hoc conductive grid, which can significantly reduce the sheet resistance of UTMF based transparent electrodes, leaving practically unchanged their transparency. The calculated highest figure-of-merit corresponds to a filling factor and a grid spacing-to-linewidth ratio of 0.025 and 39, respectively. To demonstrate the capability of the proposed method the sheet resistance of a continuous 2 nm Ni film (>950 OMEGA/square) is reduced to approx6.5 OMEGA/square when a 100 nm thick Cu grid is deposited on it. The transparency is instead maintained at values exceeding 75%. These results, which can be further improved by making thicker grids, already demonstrate the potential in applications, such as photovoltaic cells, optical detectors and displays.

Ghosh, D. S.; Chen, T. L. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Castelldefels, Barcelona, 08860 Catalunya (Spain); Pruneri, V. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Castelldefels, Barcelona, 08860 Catalunya (Spain); ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08010 Barcelona (Spain)

2010-01-25

59

Graphene as an anti-permeation and protective layer for indium-free transparent electrodes  

NASA Astrophysics Data System (ADS)

We show that graphene can be used as a protective layer for transparent electrodes made of materials which would otherwise deteriorate when exposed to the environment. In particular, we investigate aluminum-doped zinc oxides and ultrathin copper films capped with a one-atom graphene layer in damp heat (95% relative humidity and 95?°C) and high temperature (up to 180?°C) conditions. The results clearly indicate that a graphene layer can strongly reduce degradation of the electrodes’ electrical, optical properties and surface morphology, thus preserving the functionality of the transparent electrodes. The proposed technique is particularly suitable for flexible optoelectronic devices thanks to the mechanical strength of graphene when subjected to bending.

Chen, T. L.; Ghosh, D. S.; Formica, N.; Pruneri, V.

2012-10-01

60

High-performance plastic platinized counter electrode via photoplatinization technique for flexible dye-sensitized solar cells.  

PubMed

A photoplatinization technique was proposed to deposit Pt on a thin TiO(2) layer modified indium tin oxide-coated polyethylene naphthalate (ITO/PEN) substrate at low temperature (about 50 °C after 1 h of UV irradiation) for the first time. The fabrication process includes coating and hydrolyzing the tetra-n-butyl titanate to form a TiO(2)-modified layer and the photoplatinization of the modified substrate in H(2)PtCl(6)/2-propanol precursor solution under UV irradiation. The obtained platinized electrodes were used as counter electrodes (CE) for flexible dye-sensitized solar cells (FDSCs). The well-optimized platinized electrode showed high optical transmittance, up to 76.5% between 400 and 800 nm (T(av)), and the charge transfer resistance (R(ct)) was as low as 0.66 ? cm(2). A series of characterizations also demonstrated the outstanding chemical/electrochemical durability and mechanical stability of the platinized electrode. The FDSCs with TiO(2)/Ti photoanodes and the obtained CEs achieved a power conversion efficiency (PCE) up to 8.12% under rear-side irradiation (AM 1.5 illumination, 100 mW cm(-2)). The obtained CEs were also employed in all-plastic bifacial DSCs. When irradiated from the rear side, the bifacial FDSC yielded a PCE of 6.26%, which approached 90% that of front-side irradiation (6.97%). Our study revealed that, apart from serving as a functional layer for deposition of Pt, the thin TiO(2) layer modification on ITO/PEN substrates also played an important role in improving the transparency and the mechanical properties of the CE. The effect of the thickness of the TiO(2) layer for Pt coating on the performance of the CE was also investigated. PMID:23039879

Fu, Nian-Qing; Fang, Yan-Yan; Duan, Yan-Dong; Zhou, Xiao-Wen; Xiao, Xu-Rui; Lin, Yuan

2012-10-12

61

Self-assembled monolayer of graphene/Pt as counter electrode for efficient dye-sensitized solar cell.  

PubMed

Monolayer of PDDA/graphene/PDDA/H(2)PtCl(6) is fabricated on conductive glass using electrostatic layer-by-layer self-assembly technique, which is then converted to graphene/Pt monolayer for use as counter electrode in dye-sensitized solar cell (DSSC). As compared to the sputtered Pt counter electrode, the self-assembled monolayer reduces the Pt amount by about 1000-fold but exhibits comparable photovoltaic performance. This finding provides a new route to fabrication of cheap and efficient counter electrodes for flow-line production of DSSCs. PMID:21909512

Gong, Feng; Wang, Hong; Wang, Zhong-Sheng

2011-09-09

62

Improved Counter-Electrode Used in Two-Dimensional Electrochromic Writing Board  

NASA Astrophysics Data System (ADS)

In an attempt to eliminate coloring irregularity and variations in the response speed of ECDs utilizing tungsten oxide films, the electromotive force (EMF) originating in a cell was investigated as a possible cause of these undesirable characteristics. Sputtered metal-tungsten oxide cermit films were developed as an imporved method. Furthermore, a prototype two-dimensional writing board was made using Ta-WO3 cermet film mounted on a counter electrode.

Morita, Hiroshi

1985-06-01

63

Interaction of niobium counter electrodes with aluminum oxide and rare-earth oxide tunnel barriers  

Microsoft Academic Search

With the use of rare-earth oxide and aluminum oxide barriers, low-leakage-current tunnel junctions can be made if the oxidation takes place in the presence of some humidity, and if the counter electrode is not niobium. It is proposed that when these oxides form in the presence of H2O, the pores of the oxides become sealed by surface O-H groups, by

Maria Ronay; E.-E. Latta

1983-01-01

64

Carbon-nanofiber counter electrodes for quasi-solid state dye-sensitized solar cells  

Microsoft Academic Search

Carbon-nanofibers (CNFs) with antler and herringbone structures are studied as a tri-iodide (I3?) reduction electrocatalyst in combination with the liquid electrolyte or an alternative stable quasi-solid state electrolyte. The catalytic properties of the counter electrode (CE) are characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The doctor bladed low temperature CNFs-CE has faster I3? reduction rate and low

Ganapathy Veerappan; Woosung Kwon; Shi-Woo Rhee

2011-01-01

65

Nanostructured networks of single wall carbon nanotubes for highly transparent, conductive, and anti-reflective flexible electrodes  

NASA Astrophysics Data System (ADS)

Highly transparent, anti-reflective, flexible, and conductive electrodes are produced by nanopatterning of a polymer composite made of single wall carbon nanotubes (SWNTs). The formation of nanostructures creates interconnected nanotubes and vertically aligned SWNT networks which greatly improves charge transport compared to a traditionally mixed composite. These electrodes moreover possess high transparency (98% at 550 nm) and good anti-reflective properties. The use of low nanotube loadings provides an economical solution to make conductive and highly transparent flexible electrodes. The process used is simple and can be easily scaled to large areas by roll to roll processes.

Boulanger, Nicolas; Barbero, David R.

2013-07-01

66

Surface treatment effect of carbon fiber fabric counter electrode in dye sensitized solar cell.  

PubMed

Dye sensitized solar cells (DSSC) with surface modified carbon fiber fabric (CF) counter electrodes were prepared and tested. Four different type of CF were used; carbon fiber (CF); carbon fiber etched with NaOH (ECF); carbon fiber with thermally deposited platinum (CFPt); and carbon fiber etched with NaOH followed by thermal deposition of platinum (ECFPt). For comparison, DSSC with thermally Pt deposited fluorine doped tin oxide (FTO/Pt) glass counter electrode was also prepared and tested. Scanning electron microscope (SEM) proved that surface morphology of the carbon fiber was roughened by the etching process and platinum deposition process. The I-V curves of each DSSC were measured under simulated light (1 Sun, AM 1.5) to get open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and efficiency (eta). Electrochemical impedance spectroscopy of each cell was measured also. It was found that higher efficiency is obtained in order of using ECFPt > CFPt > FTO/Pt > ECF > CF counter electrode. PMID:22630028

Pak, Hunkyun; Yoo, Young Ran

2012-02-01

67

Holographic Method for the Measurement of the Sagitta of a Thin Electrode of a Parallel Plate Counter.  

National Technical Information Service (NTIS)

An holographic method for the measurement of the sagitta of the thin electrode of a position sensitive parallel plate counter is presented. The method is simple but very sensitive (about 1 mu m). (Atomindex citation 19:033428)

C. Guidi R. Bellazzini A. Brez M. M. Massai M. R. Torquati

1986-01-01

68

Formation of Porous Titanium Film and Its Application to Counter Electrode for Dye-Sensitized Solar Cell  

NASA Astrophysics Data System (ADS)

It is important to reduce the series resistance of a dye-sensitized solar cell (DSC) to improve its conversion efficiency. Here, a porous titanium (Ti)/dense Ti/aluminum (Al)/glass composite counter electrode for a DSC was fabricated. A porous and a dense Ti layer were deposited by a DC magnetron sputtering process. The dense Ti film was used as a protective layer against corrosion of the Al layer, which reduces the sheet resistance of the counter electrode. The solution treatment furthermore roughened the surface of the porous Ti layer. The composite counter electrode increased the fill factor and short-circuit current, resulting in the improvement of the conversion efficiency of the DSC. Our results indicate that it is important to introduce a porous material to the counter electrode of the DSC to improve the performance of the DSC and that the porous Ti film with rough surfaces is a promising material.

Rahman, Mohammad Maksudur; Kojima, Ryota; Fihry, Mehdi El Fassy; Kimura, Yasuo; Niwano, Michio

2010-12-01

69

Broadband light absorption enhancement in polymer photovoltaics using metal nanowall gratings as transparent electrodes.  

PubMed

The authors investigate light absorption in organic solar cells in which indium tin oxide (ITO) is replaced by a new metallic architecture (grating) as a transparent electrode. Different from typical metal nanowire gratings, our gratings consist of metal nanowalls with nanoscale footprint and (sub)microscale height [Adv. Mater. 23, 2469 (2011)], thus ensuring high optical transmittance and electrical conductivity. Simulations reveal that a broadband and polarization-insensitive light absorption enhancement is achieved via two mechanisms, when such silver nanowall gratings are employed in P3HT:PCBM based solar cells. Overall absorption enhanced by ~23% compared to a reference cell with ITO electrode. PMID:22714211

Ye, Zhuo; Chaudhary, Sumit; Kuang, Ping; Ho, Kai-Ming

2012-05-21

70

Broadband light absorption enhancement in polymer photovoltaics using metal nanowall gratings as transparent electrodes  

SciTech Connect

The authors investigate light absorption in organic solar cells in which indium tin oxide (ITO) is replaced by a new metallic architecture (grating) as a transparent electrode. Different from typical metal nanowire gratings, our gratings consist of metal nanowalls with nanoscale footprint and (sub)microscale height [Adv. Mater. 23, 2469 (2011)], thus ensuring high optical transmittance and electrical conductivity. Simulations reveal that a broadband and polarization-insensitive light absorption enhancement is achieved via two mechanisms, when such silver nanowall gratings are employed in P3HT:PCBM based solar cells. Overall absorption enhanced by ~23% compared to a reference cell with ITO electrode.

Ye, Zhuo; Chaudhary, Sumit; Kuang, Ping; Ho, Kai-Ming

2012-05-15

71

Organic photovoltaic devices using highly flexible reduced graphene oxide films as transparent electrodes.  

PubMed

The chemically reduced graphene oxide (rGO) was transferred onto polyethylene terephthalate (PET) substrates and then used as transparent and conductive electrodes for flexible organic photovoltaic (OPV) devices. The performance of the OPV devices mainly depends on the charge transport efficiency through rGO electrodes when the optical transmittance of rGO is above 65%. However, if the transmittance of rGO is less than 65%, the performance of the OPV device is dominated by the light transmission efficiency, that is, the transparency of rGO films. After the tensile strain (?2.9%) was applied on the fabricated OPV device, it can sustain a thousand cycles of bending. Our work demonstrates the highly flexible property of rGO films, which provide the potential applications in flexible optoelectronics. PMID:20738121

Yin, Zongyou; Sun, Shuangyong; Salim, Teddy; Wu, Shixin; Huang, Xiao; He, Qiyuan; Lam, Yeng Ming; Zhang, Hua

2010-09-28

72

Transfer of large-area graphene films for high-performance transparent conductive electrodes.  

PubMed

Graphene, a two-dimensional monolayer of sp(2)-bonded carbon atoms, has been attracting great interest due to its unique transport properties. One of the promising applications of graphene is as a transparent conductive electrode owing to its high optical transmittance and conductivity. In this paper, we report on an improved transfer process of large-area graphene grown on Cu foils by chemical vapor deposition. The transferred graphene films have high electrical conductivity and high optical transmittance that make them suitable for transparent conductive electrode applications. The improved transfer processes will also be of great value for the fabrication of electronic devices such as field effect transistor and bilayer pseudospin field effect transistor devices. PMID:19845330

Li, Xuesong; Zhu, Yanwu; Cai, Weiwei; Borysiak, Mark; Han, Boyang; Chen, David; Piner, Richard D; Colombo, Luigi; Ruoff, Rodney S

2009-12-01

73

A solution processed top emission OLED with transparent carbon nanotube electrodes.  

PubMed

Top emission organic light emitting diodes (OLEDs) with carbon nanotubes (CNTs) as top electrodes were fabricated and characterized. Devices were fabricated on glass substrates with evaporated bottom Al/LiF cathodes, a spin coated organic emissive layer and a PEDOT-PSS hole injection layer. Transparent thin CNT films were deposited on top of the emission layer to form the anode by micro-contact printing with a polydimethylsiloxane stamp. A very good device performance was obtained, with a peak luminance of 3588 cd m(-2) and a maximum current efficiency of 1.24 cd A(-1). This work shows the possibility of using CNTs as transparent electrodes to replace ITO in organic semiconductor devices. Furthermore, the top emission nature of such devices offers a broader range of applications of CNTs on any type of substrate. By combining with solution processed organic materials, it is anticipated that lower cost fabrication will be possible through roll-to-roll manufacture. PMID:20208120

Chien, Yu-Mo; Lefevre, Florent; Shih, Ishiang; Izquierdo, Ricardo

2010-03-08

74

Outstanding flexibility of organic memory devices with transparent graphene top electrodes  

Microsoft Academic Search

The organic memory device was fabricated 8 × 8 cross-bar array-type with transparent graphene electrodes on a poly(ethylene terephthalate) (PET) substrate. The active layer of the memory devices is a composite of polyimide and 6-phenyl-C61 butyric acid methyl ester (PCBM). The sheet resistance of the graphene film on memory device was found to be ?270?\\/?, and the transmittance of separated

Yongsung Ji; Sangchul Lee; Byungjin Cho; Sunghoon Song; Takhee Lee

2011-01-01

75

Flexible, transparent single-walled carbon nanotube transistors with graphene electrodes.  

PubMed

This paper reports a mechanically flexible, transparent thin film transistor that uses graphene as a conducting electrode and single-walled carbon nanotubes (SWNTs) as a semiconducting channel. These SWNTs and graphene films were printed on flexible plastic substrates using a printing method. The resulting devices exhibited a mobility of ? 2 cm(2) V(-1) s -1), On/Off ratio of ? 10(2), transmittance of ? 81% and excellent mechanical bendability. PMID:20858937

Jang, Sukjae; Jang, Houk; Lee, Youngbin; Suh, Daewoo; Baik, Seunghyun; Hong, Byung Hee; Ahn, Jong-Hyun

2010-09-22

76

Scaling behaviour of a-IGZO TFTs with transparent a-IZO source\\/drain electrodes  

Microsoft Academic Search

We analysed the scaling behaviour of amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs) with amorphous indium zinc oxide (a-IZO) transparent source\\/drain (S\\/D) electrodes. Due to the sputtering damage of the back-channel region during the a-IZO deposition process, the output characteristics show early saturation behaviour and the field-effect mobility in the saturation region is severely decreased in comparison with

Jaewook Jeong; Gwang Jun Lee; Joonwoo Kim; Byeongdae Choi

2012-01-01

77

Transparent Electrode Patterning using Laser Ablation for In-Plane Switching Liquid Crystal Display  

NASA Astrophysics Data System (ADS)

Transparent indium tin oxides (ITO) electrodes were patterned using flash lamp pumped Q-switched Nd: YAG laser ablation technique. The Optical microscopy, atomic force microscopy and energy dispersive x-ray spectrum along with scanning electron microscope analysis shows the depth and width of the ablated area and the elements available in the ablated area. In-plane switching liquid crystal display were constructed using the patterned indium tin oxide and its switching characteristics are investigated.

Chenchiliyan, Manoop; Palengara, Sudheesh; Varghese, Soney

2011-10-01

78

Silver nanowire/optical adhesive coatings as transparent electrodes for flexible electronics.  

PubMed

We present new flexible, transparent, and conductive coatings composed of an annealed silver nanowire network embedded in a polyurethane optical adhesive. These coatings can be applied to rigid glass substrates as well as to flexible polyethylene terephthalate (PET) plastic and elastomeric polydimethylsiloxane (PDMS) substrates to produce highly flexible transparent conductive electrodes. The coatings are as conductive and transparent as indium tin oxide (ITO) films on glass, but they remain conductive at high bending strains and are more durable to marring and scratching than ITO. Coatings on PDMS withstand up to 76% tensile strain and 250 bending cycles of 15% strain with a negligible increase in electrical resistance. Since the silver nanowire network is embedded at the surface of the optical adhesive, these coatings also provide a smooth surface (root mean squared surface roughness <10 nm), making them suitable as transparent conducting electrodes in flexible light-emitting electrochemical cells. These devices continue to emit light even while being bent to radii as low as 1.5 mm and perform as well as unstrained devices after 20 bending cycles of 25% tensile strain. PMID:24007382

Miller, Michael S; O'Kane, Jessica C; Niec, Adrian; Carmichael, R Stephen; Carmichael, Tricia Breen

2013-10-03

79

Three-dimensional graphene foam-based transparent conductive electrodes in GaN-based blue light-emitting diodes  

NASA Astrophysics Data System (ADS)

We demonstrated three-dimensional (3D) graphene foam-based transparent conductive electrodes in GaN-based blue light-emitting diodes (LEDs). A 3D graphene foam structure grown on 3D Cu foam using a chemical vapor deposition method was transferred onto a p-GaN layer of blue LEDs. Optical and electrical performances were greatly enhanced by employing 3D graphene foam as transparent conductive electrodes in blue LED devices, which were analyzed by electroluminescence measurements, micro-Raman spectroscopy, and light intensity-current-voltage testing. The forward operating voltage and the light output power at an injection current of 100 mA of the GaN-based blue LEDs with a graphene foam-based transparent conductive electrode were improved by ~26% and ~14%, respectively. The robustness, high transmittance, and outstanding conductivity of 3D graphene foam show great potentials for advanced transparent conductive electrodes in optoelectronic devices.

Kim, Byung-Jae; Yang, Gwangseok; Joo Park, Min; Seop Kwak, Joon; Hyeon Baik, Kwang; Kim, Donghwan; Kim, Jihyun

2013-04-01

80

Roll-to-roll production of 30-inch graphene films for transparent electrodes  

NASA Astrophysics Data System (ADS)

The outstanding electrical1, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates. The films have sheet resistances as low as ˜125 Ohm/sq with 97.4% optical transmittance, and exhibit the half-integer quantum Hall effect, indicating their high quality. We further use layer-by-layer stacking to fabricate a doped four-layer film and measure its sheet resistance at values as low as ˜30 Ohm/sq at ˜90% transparency, which is superior to commercial transparent electrodes such as indium tin oxides. Graphene electrodes were incorporated into a fully functional touch-screen panel device capable of withstanding high strain.

Hong, Byung Hee

2011-03-01

81

Roll-to-roll production of 30-inch graphene films for transparent electrodes.  

PubMed

The outstanding electrical, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates. The films have sheet resistances as low as approximately 125 ohms square(-1) with 97.4% optical transmittance, and exhibit the half-integer quantum Hall effect, indicating their high quality. We further use layer-by-layer stacking to fabricate a doped four-layer film and measure its sheet resistance at values as low as approximately 30 ohms square(-1) at approximately 90% transparency, which is superior to commercial transparent electrodes such as indium tin oxides. Graphene electrodes were incorporated into a fully functional touch-screen panel device capable of withstanding high strain. PMID:20562870

Bae, Sukang; Kim, Hyeongkeun; Lee, Youngbin; Xu, Xiangfan; Park, Jae-Sung; Zheng, Yi; Balakrishnan, Jayakumar; Lei, Tian; Kim, Hye Ri; Song, Young Il; Kim, Young-Jin; Kim, Kwang S; Ozyilmaz, Barbaros; Ahn, Jong-Hyun; Hong, Byung Hee; Iijima, Sumio

2010-06-20

82

Roll-to-roll production of 30-inch graphene films for transparent electrodes  

NASA Astrophysics Data System (ADS)

The outstanding electrical, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates. The films have sheet resistances as low as ~125 ? ?-1 with 97.4% optical transmittance, and exhibit the half-integer quantum Hall effect, indicating their high quality. We further use layer-by-layer stacking to fabricate a doped four-layer film and measure its sheet resistance at values as low as ~30 ? ?-1 at ~90% transparency, which is superior to commercial transparent electrodes such as indium tin oxides. Graphene electrodes were incorporated into a fully functional touch-screen panel device capable of withstanding high strain.

Bae, Sukang; Kim, Hyeongkeun; Lee, Youngbin; Xu, Xiangfan; Park, Jae-Sung; Zheng, Yi; Balakrishnan, Jayakumar; Lei, Tian; Ri Kim, Hye; Song, Young Il; Kim, Young-Jin; Kim, Kwang S.; Özyilmaz, Barbaros; Ahn, Jong-Hyun; Hong, Byung Hee; Iijima, Sumio

2010-08-01

83

Direct tri-constituent co-assembly of highly ordered mesoporous carbon counter electrode for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

Controlling over ordered porosity by self-assembly is challenging in the area of materials science. Materials with highly ordered aperture are favorable candidates in catalysis and energy conversion device. Here we describe a facile process to synthesize highly ordered mesoporous carbon (OMC) by direct tri-constituent co-assembly method, which uses resols as the carbon precursor, tri-block copolymer F127 as the soft template and tetraethoxysilane (TEOS) as the inorganic precursor. The obtained products are characterized by small-angle X-ray diffraction (SAXD), Brunauer-Emmett-Teller (BET) nitrogen sorption-desorption measurement and transmission electron microscope (TEM). The results indicate that the OMC possesses high surface areas of 1209 m2 g-1, homogeneous pore size of 4.6 nm and a large pore volume of 1.65 cm3 g-1. The advantages of high electrochemical active surface area and favorable accessible porosity of OMC benefit the catalysis of I3- to I-. As a result, the OMC counter electrode displays a remarkable property when it was applied in dye-sensitized solar cells (DSSCs). For comparison, carbon black (CB) counter electrode and Pt counter electrode have also been prepared. When these different counter electrodes were applied for dye-sensitized solar cells (DSSCs), the power-conversion efficiency (?) of the DSSCs with CB counter electrode are measured to be 5.10%, whereas the corresponding values is 6.39% for the DSSC with OMC counter electrode, which is comparable to 6.84% of the cell with Pt counter electrode under the same experimental conditions.

Peng, Tao; Sun, Weiwei; Sun, Xiaohua; Huang, Niu; Liu, Yumin; Bu, Chenghao; Guo, Shishang; Zhao, Xing-Zhong

2012-12-01

84

Direct tri-constituent co-assembly of highly ordered mesoporous carbon counter electrode for dye-sensitized solar cells.  

PubMed

Controlling over ordered porosity by self-assembly is challenging in the area of materials science. Materials with highly ordered aperture are favorable candidates in catalysis and energy conversion device. Here we describe a facile process to synthesize highly ordered mesoporous carbon (OMC) by direct tri-constituent co-assembly method, which uses resols as the carbon precursor, tri-block copolymer F127 as the soft template and tetraethoxysilane (TEOS) as the inorganic precursor. The obtained products are characterized by small-angle X-ray diffraction (SAXD), Brunauer-Emmett-Teller (BET) nitrogen sorption-desorption measurement and transmission electron microscope (TEM). The results indicate that the OMC possesses high surface areas of 1209 m(2) g(-1), homogeneous pore size of 4.6 nm and a large pore volume of 1.65 cm(3) g(-1). The advantages of high electrochemical active surface area and favorable accessible porosity of OMC benefit the catalysis of I(3)(-) to I(-). As a result, the OMC counter electrode displays a remarkable property when it was applied in dye-sensitized solar cells (DSSCs). For comparison, carbon black (CB) counter electrode and Pt counter electrode have also been prepared. When these different counter electrodes were applied for dye-sensitized solar cells (DSSCs), the power-conversion efficiency (?) of the DSSCs with CB counter electrode are measured to be 5.10%, whereas the corresponding values is 6.39% for the DSSC with OMC counter electrode, which is comparable to 6.84% of the cell with Pt counter electrode under the same experimental conditions. PMID:23165970

Peng, Tao; Sun, Weiwei; Sun, Xiaohua; Huang, Niu; Liu, Yumin; Bu, Chenghao; Guo, Shishang; Zhao, Xing-Zhong

2012-11-20

85

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

NASA Astrophysics Data System (ADS)

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 ? to 30 ? as observed by electrochemical impedance spectroscopy.

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

2012-06-01

86

Highly Flexible and Transparent Multilayer MoS2 Transistors with Graphene Electrodes.  

PubMed

A highly flexible and transparent transistor is developed based on an exfoliated MoS2 channel and CVD-grown graphene source/drain electrodes. Introducing the 2D nanomaterials provides a high mechanical flexibility, optical transmittance (?74%), and current on/off ratio (>10(4) ) with an average field effect mobility of ?4.7 cm(2) V(-1) s(-1) , all of which cannot be achieved by other transistors consisting of a MoS2 active channel/metal electrodes or graphene channel/graphene electrodes. In particular, a low Schottky barrier (?22 meV) forms at the MoS2 /graphene interface, which is comparable to the MoS2 /metal interface. The high stability in electronic performance of the devices upon bending up to ±2.2 mm in compressive and tensile modes, and the ability to recover electrical properties after degradation upon annealing, reveal the efficacy of using 2D materials for creating highly flexible and transparent devices. PMID:23420782

Yoon, Jongwon; Park, Woojin; Bae, Ga-Yeong; Kim, Yonghun; Jang, Hun Soo; Hyun, Yujun; Lim, Sung Kwan; Kahng, Yung Ho; Hong, Woong-Ki; Lee, Byoung Hun; Ko, Heung Cho

2013-02-18

87

Synthesis of Graphene Films by Chemical Vapor Deposition for Transparent Conducting Electrodes of GaN Light-Emitting Diodes  

NASA Astrophysics Data System (ADS)

This work demonstrales large-scale simultaneous fabrication of patterned graphene-based GaN light-emitting diodes (LEDs). Graphene sheets were synthesized using a chemical vapor deposition (CVD) technique on nickel films and showed typical CVD-synthesized film properties, possessing a sheet resistance of ~605 ?/\\squarelg with a transparency of more than 85% in the 400-800 nm wavelength range, and was applied as transparent condueting electrodes of GaN-based blue LHDs, The light output performance of GaN LEDs with graphene electrodes was comparable to that of conventional ITO-electrode LEDs over the range of input current up to 150 mA.

Jo, Gunho; Choe, Minhyeok; Cho, Chu-Young; Kim, Jin Ho; Park, Woojin; Lee, Sangchul; Park, Seong-Ju; Hong, Byung Hee; Kahng, Yung Ho; Lee, Takhee

2011-12-01

88

Intrinsically stretchable transparent electrodes based on silver-nanowire-crosslinked-polyacrylate composites  

NASA Astrophysics Data System (ADS)

Stretchable transparent composites have been synthesized consisting of a silver nanowire (AgNW) network embedded in the surface layer of a crosslinked poly(acrylate) matrix. The interpenetrating networks of AgNWs and the crosslinked polymer matrix lead to high surface conductivity, high transparency, and rubbery elasticity. The presence of carboxylic acid groups on the polymer chains enhances the bonding between AgNWs and the polymer matrix, and further increases the stretchability of the composites. The sheet resistance of the composite electrode increases by only 2.3 times at 50% strain. Repeated stretching to 50% strain and relaxation only causes a small increase of the sheet resistance after 600 cycles. The morphology of the composites during reversible stretching and relaxation has been investigated to expound the conductivity changes.

Hu, Weili; Niu, Xiaofan; Li, Lu; Yun, Sungryul; Yu, Zhibin; Pei, Qibing

2012-08-01

89

Wet Etching of TiO2-Based Precursor Amorphous Films for Transparent Electrodes  

NASA Astrophysics Data System (ADS)

We investigated wet etching of Nb-doped anatase TiO2 (TNO) transparent conducting thin films and their precursors in an amorphous phase deposited by rf sputtering on glass substrates. The polycrystalline TNO films showed a very low etching rate of less than 0.06 nm/min in concentrated sulfuric acid (H2SO4) even at elevated temperatures up to 95 °C. In contrast, H2SO4 etched the precursor films at a rate of 1.4 nm/min at 95 °C. The etching rate of the amorphous films followed the Arrhenius equation, leading us to conjecture that a much higher etching rate of ˜230 nm/min can be achieved at 170 °C. These results indicate that wet-etching of precursor amorphous films prior to crystallization represents a practical and low-cost lithographic technique for patterning TiO2-based transparent electrodes.

Ohkubo, Junpei; Hirose, Yasushi; Sakai, Enju; Nakao, Shoichiro; Hitosugi, Taro; Hasegawa, Tetsuya

2011-01-01

90

Noncatalytic chemical vapor deposition of graphene on high-temperature substrates for transparent electrodes  

NASA Astrophysics Data System (ADS)

A noncatalytic chemical vapor deposition mechanism is proposed, where high precursor concentration, long deposition time, high temperature, and flat substrate are needed to grow large-area nanocrystalline graphene using hydrocarbon pyrolysis. The graphene is scalable, uniform, and with controlled thickness. It can be deposited on virtually any nonmetallic substrate that withstands ~1000 °C. For typical examples, graphene grown directly on quartz and sapphire shows transmittance and conductivity similar to exfoliated or metal-catalyzed graphene, as evidenced by transmission spectroscopy and transport measurements. Raman spectroscopy confirms the sp2-C structure. The model and results demonstrate a promising transfer-free technique for transparent electrode production.

Sun, Jie; Cole, Matthew T.; Lindvall, Niclas; Teo, Kenneth B. K.; Yurgens, August

2012-01-01

91

Optimization of Transparent Electrode for Solar Cell and Chemical Vapor Deposition of Amorphous Silicon. Final Technical Report, 15 September 1980-30 March 1983.  

National Technical Information Service (NTIS)

Solar photovoltaic cell designs usually benefit from a front surface which is both transparent and highly conductive to electricity. A practical transparent electrode layer must also be durable, stable to weathering and sunlight, inexpensive, nontoxic, no...

R. Gordon J. Proscia F. Ellis S. Kurtz

1984-01-01

92

Strong and stable doping of carbon nanotubes and graphene by MoOx for transparent electrodes.  

PubMed

MoO(x) has been used for organic semiconductor doping, but it had been considered an inefficient and/or unstable dopant. We report that MoO(x) can strongly and stably dope carbon nanotubes and graphene. Thermally annealed MoO(x)-CNT composites can form durable thin film electrodes with sheet resistances of 100 ?/sq at 85% transmittance plain and 85 ?/sq at 83% transmittance with a PEDOT:PSS adlayer. Sheet resistances change less than 10% over 20 days in ambient and less than 2% with overnight heating to 300 °C in air. The MoO(x) can be easily deposited either by thermal evaporation or from solution-based precursors. Excellent stability coupled with high conductivity makes MoO(x)-CNT composites extremely attractive candidates for practical transparent electrodes. PMID:22694046

Hellstrom, Sondra L; Vosgueritchian, Michael; Stoltenberg, Randall M; Irfan, Irfan; Hammock, Mallory; Wang, Yinchao Bril; Jia, Chuancheng; Guo, Xuefeng; Gao, Yongli; Bao, Zhenan

2012-06-13

93

Large-Area, Transparent And Conductive Graphene Electrode For Bulk-Heterojunction Photovoltaic Devices  

NASA Astrophysics Data System (ADS)

We present application results of synthesized graphene films as transparent and conductive electrodes of organic photovoltaic devices. The graphene films were synthesized by chemical vapor deposition (CVD) technique on nickel substrates and showed a low sheet resistance of ~605 ?/\\squarelg and transmittance of 87% in the visible wavelength range. The performance of graphene-applied organic photovoltaic cell was enhanced by intermediating TiOX layer to yield an overall power conversion efficiency of 2.60% which is the higher efficiency among the efficiencies of photovoltaic cells with graphene electrodes. Our demonstration of highly efficient graphene-adopted photovoltaic cells may foster thrusting the fast-progressing graphene technology into the practical realm of organic photovoltaic cells.

Choe, Minhyeok; Lee, Byoung Hoon; Jo, Gunho; Park, June; Park, Woojin; Lee, Sangchul; Hong, Woong-Ki; Seong, Maeng-Je; Kahng, Yung Ho; Lee, Kwanghee; Lee, Takhee

2011-12-01

94

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

PubMed

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

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

2012-06-19

95

Chemical doping of large-area stacked graphene films for use as transparent, conducting electrodes.  

PubMed

Graphene is considered a leading candidate to replace conventional transparent conducting electrodes because of its high transparency and exceptional transport properties. The effect of chemical p-type doping on graphene stacks was studied in order to reduce the sheet resistance of graphene films to values approaching those of conventional transparent conducting oxides. In this report, we show that large-area, stacked graphene films are effectively p-doped with nitric acid. The doping decreases the sheet resistance by a factor of 3, yielding films comprising eight stacked layers with a sheet resistance of 90 Omega/(square) at a transmittance of 80%. The films were doped either after all of the layers were stacked (last-layer-doped) or after each layer was added (interlayer-doped). A theoretical model that accurately describes the stacked graphene film system as a resistor network was developed. The model defines a characteristic transfer length where all the channels in the graphene films actively contribute to electrical transport. The experimental data shows a linear increase in conductivity with the number of graphene layers, indicating that each layer provides an additional transport channel, in good agreement with the theoretical model. PMID:20695514

Kasry, Amal; Kuroda, Marcelo A; Martyna, Glenn J; Tulevski, George S; Bol, Ageeth A

2010-07-27

96

Investigations on the electrochemical behaviour of the phase boundary counter electrode\\/electrolyte of amperometric solid electrolyte gas sensors based on Ag ?-alumina  

Microsoft Academic Search

Amperometric gas sensors based on solid silver ion conductors, e.g. chlorine gas sensors, usually contain silver electrodes as counter electrodes or common counter\\/reference electrodes. The electrochemical kinetic behaviour of the system Ag electrode\\/Ag ?-alumina solid electrolyte has been investigated in the temperature range between 275 and 375°C. The measurements have been carried out using different types of solid-state electrochemical cells.

Maria Petrova-Nikolova; Jürgen P. Pohl

1998-01-01

97

Solid-state dye-sensitized solar cells using polymerized ionic liquid electrolyte with platinum-free counter electrode.  

PubMed

A polymerized ionic liquid electrolyte and platinum-free counter electrode are employed for solid-state DSSCs. We are able to prepare a thin polymer electrolyte layer on nanocrystalline TiO(2) in order to reduce the cell resistance. In addition, an electron conductive polymer (PEDOT/PSS) or a single-wall carbon nanotube gel is used with the cell as an inexpensive counter electrode instead of platinum. The overall photon-to-current conversion efficiency was 3.7% in this study. PMID:20145859

Kawano, Ryuji; Katakabe, Toru; Shimosawa, Hironobu; Nazeeruddin, Md Khaja; Grätzel, Michael; Matsui, Hiroshi; Kitamura, Takayuki; Tanabe, Nobuo; Watanabe, Masayoshi

2010-01-28

98

Enhanced Second-Order Resonance Actuation and Frequency Response Modulation of Microcantilever by Dual Coplanar Counter Electrodes  

NASA Astrophysics Data System (ADS)

We achieve enhanced actuation of the 2nd-order resonance of a microcantilever in a capacitive microcantilever structure featured by a dual coplanar counter electrodes configuration. A torque about the static point of the 2nd eigenmode is generated in this configuration and therefore enables effective actuation of the 2nd-order resonance. It is further confirmed that the torque has the effect of suppressing the 1st-order resonance. As a result, the frequency response curve of the microcantilever beam can be modulated. Our results suggest that electric actuation of any higher-order resonances of the microcantilever can be realized through a rational design of counter electrodes.

Feng, Zhao-Bin; Liu, Duo

2013-10-01

99

Unraveling the physics of vertical organic field effect transistors through nanoscale engineering of a self-assembled transparent electrode.  

PubMed

While organic transistors' performances are continually pushed to achieve lower power consumption, higher working frequencies, and higher current densities, a new type of organic transistors characterized by a vertical architecture offers a radically different design approach to outperform its traditional counterparts. Naturally, the distinct vertical architecture gives way to different governing physical ground rules and structural key features such as the need for an embedded transparent electrode. In this paper, we make use of a zero-frequency electric field-transparent patterned electrode produced through block-copolymer self-assembly based lithography to control the performances of the vertical organic field effect transistor (VOFET) and to study its governing physical mechanisms. Unlike other VOFET structures, this design, involving well-defined electrode architecture, is fully tractable, allowing for detailed modeling, analysis, and optimization. We provide for the first time a complete account of the physics underpinning the VOFET operation, considering two complementary mechanisms: the virtual contact formation (Schottky barrier lowering) and the induced potential barrier (solid-state triode-like shielding). We demonstrate how each mechanism, separately, accounts for the link between controllable nanoscale structural modifications in the patterned electrode and the VOFET performances. For example, the ON/OFF current ratio increases by up to 2 orders of magnitude when the perforations aspect ratio (height/width) decreases from ?0.2 to ?0.1. The patterned electrode is demonstrated to be not only penetrable to zero-frequency electric fields but also transparent in the visible spectrum, featuring uniformity, spike-free structure, material diversity, amenability with flexible surfaces, low sheet resistance (20-2000 ? sq(-1)) and high transparency (60-90%). The excellent layer transparency of the patterned electrode and the VOFET's exceptional electrical performances make them both promising elements for future transparent and/or efficient organic electronics. PMID:22934789

Ben-Sasson, Ariel J; Tessler, Nir

2012-08-30

100

Efficient platinum-free counter electrodes for dye-sensitized solar cell applications.  

PubMed

Nanoporous layers of poly(3,4-propylenedioxythiophene) (PProDOT) were fabricated by electrical-field-assisted growth using hydrophobic ionic liquids as the growing medium. A series of PProDoT layers was prepared with three different ionic liquids to control the microstructure and electrochemical properties of the resulting dye-sensitized solar cells, which were highly efficient and showed a power conversion efficiency of >9% under different sunlight intensities. The current-voltage characteristics of the counter electrodes varied depending on the ionic liquids used in the synthesis of PProDOT. The most hydrophobic ionic liquids exhibited high catalytic properties, thus resulting in high power conversion efficiency and allowing the fabrication of platinum-free, stable, flexible, and cost-effective dye-sensitized solar cells. PMID:20740548

Ahmad, Shahzada; Yum, Jun-Ho; Butt, Hans-Jürgen; Nazeeruddin, Mohammad K; Grätzel, Michael

2010-09-10

101

Nanopatterned conductive polymer films as a Pt, TCO-free counter electrode for low-cost dye-sensitized solar cells.  

PubMed

A low-cost nanopatterned highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin film was fabricated on a flexible plastic substrate via a chemical polymerization method combined with a nanoimprinting technique and used as a platinum (Pt), TCO-free counter electrode for dye-sensitized solar cells (DSSCs). The catalytic properties of the nanopatterned PEDOT as the counter electrode in DSSCs were studied using cyclic voltammetry, J-V measurements, impedance spectroscopy, and finite-difference time-domain (FDTD) simulations. The nanopatterned PEDOT counter electrodes exhibit better functionality as a counter electrode for tri-iodide reduction when compared to non-patterned PEDOT-based counter electrodes. The Pt and TCO-free DSSCs with a nanopatterned PEDOT-based counter electrode exhibited a power conversion efficiency of 7.1% under one sunlight illumination (100 mW cm(-2)), which is comparable to that of conventional DSSCs with standard platinum Pt/FTO paired counter electrodes. The ability to modulate catalytic functionality with changes in nanoscale morphology represents a promising route for developing new counter electrodes of Pt and TCO-free DSSCs. PMID:23852259

Kwon, Jeong; Ganapathy, Veerappan; Kim, Young Hun; Song, Kyung-Deok; Park, Hong-Gyu; Jun, Yongseok; Yoo, Pil J; Park, Jong Hyeok

2013-09-01

102

Performance and durability of electrochromic windows with carbon-based counter electrode and their application in the architectural and automotive fields  

Microsoft Academic Search

We propose a carbon-based counter electrode for electrochromic windows (ECWs). The electrochemical durability of carbon materials has been verified in practical applications such as commercially available electrical double-layer capacitors, and the proposed counter electrode can store charges in an electric double layer irrespective of their charge polarities. The latter factor is expected to enhance the durability of ECWs, especially against

T. Kubo; J. Tanimoto; M. Minami; T. Toya; Y. Nishikitani; H. Watanabe

2003-01-01

103

Transparent, highly conductive graphene electrodes from acetylene-assisted thermolysis of graphite oxide sheets and nanographene molecules  

Microsoft Academic Search

Transparent and highly conductive graphene electrodes have been fabricated through acetylene-assisted thermolysis of graphite oxide (GO) sheets. This novel procedure uses acetylene as a supplemental carbon source to repair substantial defects within GO sheets, leading to the enhancement of graphitization of synthesized graphene electrodes. The as-prepared graphene on quartz substrates exhibits an electrical conductivity of 1425 S cm-1 with an

Yanyu Liang; Johannes Frisch; Linjie Zhi; Hassan Norouzi-Arasi; Xinliang Feng; Jürgen P. Rabe; Norbert Koch; Klaus Müllen

2009-01-01

104

Design rules for highly transparent electrodes using dielectric constant matching of metal oxide with Ag film in optoelectronic devices.  

PubMed

Using dielectric-constant (?) matching of metal-oxide (MO) with Ag film, highly transparent MO/Ag electrodes are demonstrated. At the large-? MO/Ag interface, surface-plasmon was suppressed and the film showed increased optical-transmittance (>70%). OLEDs fabricated using large-? MO/Ag electrodes show 1.38 times greater luminance than that of devices with small-? MO/Ag. PMID:22948249

Hong, Kihyon; Son, Jun Ho; Kim, Sungjun; Koo, Bon Hyeong; Lee, Jong-Lam

2012-11-01

105

High-Performance Flexible a-IGZO TFTs Adopting Stacked Electrodes and Transparent Polyimide-Based Nanocomposite Substrates  

Microsoft Academic Search

We demonstrated flexible amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) on fully transparent and high-temperature polyimide-based nanocomposite substrates. The flexible nanocomposite substrates were coated on the carrier glass substrates and were debonded after the TFT microfabrication. The adoption of the Ti\\/IZO stacked electrodes as source\\/drain\\/ gain electrodes significantly improved the etching compatibility with other material layers, enabling successful implementation of flexible

Chih-Wei Chien; Cheng-Han Wu; Yu-Tang Tsai; Yen-Cheng Kung; Chang-Yu Lin; Po-Ching Hsu; Hsing-Hung Hsieh; Chung-Chih Wu; Yung-Hui Yeh; Chyi-Ming Leu; Tzong-Ming Lee

2011-01-01

106

Transparent Multi-layer Conductive Electrode Film Prepared by DC Sputter Deposition and its Flat Panel Display Application  

Microsoft Academic Search

Multi-layer conductive electrode films to be used as substrate for a plastic liquid crystal display (LCD) were prepared by the DC magnetron roll-to-roll sputtering method. The conductive layer is consisted of three layers, ITO\\/Ag\\/ITO, ITO\\/APC\\/ITO and SnO 2 \\/Ag\\/ITO, on the polymer substrate. The multi-layered conductive electrode has sheet resistance of about 5-8 ?\\/square, optical transparency of 85-88 % at

Jinyeol Kim; Jaegeun Noh; Daewoo Ihm

2002-01-01

107

Pattern transfer of aligned metal nano/microwires as flexible transparent electrodes using an electrospun nanofiber template  

NASA Astrophysics Data System (ADS)

Due to the scarcity and high cost of indium, the predominant use of indium tin oxide (ITO) films as transparent electrodes has attracted great attention for finding a potential replacement, such as solution-processed networks of carbon nanotubes, graphene, or silver nanowires (NWs). More recently, the use of electrospun copper NWs as high-performance electrodes with a high aspect ratio of 100?000 and 90% transmittance at 50 ?/sq was experimentally achieved. However, the fabrication route of the Cu nanofiber (NF) web includes two high temperature processes (calcined 2 h in air at 500?°C and annealed 1 h in hydrogen at 300?°C). In this paper, we propose a new method to obtain metal nano/microwires to be used as flexible transparent electrodes by using electrospun NF templates and the dry pattern transfer process. Our proposed method is advantageous because we can easily tune the conductivity and transmittance (T) via sputtering time in minutes without the need for time-consuming high temperature thermal steps. Here, we comprehensively show the transferred high performance transparent electrodes with platinum (Pt)-coated NW electrodes with a facile and scalable electrospinning combined sputtering process. Pt-coated NWs have high aspect ratios of up to 5000 and, when sputtered with Pt, reduce junction resistance, which results in high T at low sheet resistance, e.g. 90% at 131 ?/sq. The Pt-coated NW electrodes also show great flexibility and stretchability, which easily surpass the brittleness of ITO films.

Fuh, Yiin-Kuen; Lien, Li-Chih

2013-02-01

108

All-metal-electrode-type dye sensitized solar cells (transparent conductive oxide-less dye sensitized solar cell) consisting of thick and porous Ti electrode with straight pores  

NASA Astrophysics Data System (ADS)

Transparent conductive oxide (TCO) layer-less dye sensitized solar cells (DSCs) are reported. The cell is composed of a glass substrate, TiO2 porous layer stained with dye molecules, porous Ti electrode, electrolyte, and a Pt sputtered Ti sheet. The cell exhibits an efficiency of 7.43% which was a little less than that of 8.44% for a DSC consisting of a TCO glass. The high efficiency was brought about by the thick and porous Ti electrode (200-300 nm thickness) which kept high conductivity and swift ionic diffusion. The preparation process for the Ti electrode is reported.

Kashiwa, Yohei; Yoshida, Yorikazu; Hayase, Shuzi

2008-01-01

109

Electrostatic spray deposition of highly transparent silver nanowire electrode on flexible substrate.  

PubMed

In this work, a modified polyol synthesis by adding KBr and by replacing the AgCl with NaCl seed was used to obtain high quality silver nanowires with long aspect ratios with an average length of 13.5 ?m in length and 62.5 nm in diameter. The Ag nanowires suspended in methanol solution after removing any unwanted particles using a glass filter system were then deposited on a flexible polycarbonate substrate using an electrostatic spray system. Transmittance of 92.1% at wavelength of 550 nm with sheet resistance of 20 ?/sq and haze of 4.9% were measured for the electrostatic sprayed Ag nanowire transparent electrode. PMID:23277228

Kim, Taegeon; Canlier, Ali; Kim, Geun Hong; Choi, Jaeho; Park, Minkyu; Han, Seung Min

2013-01-30

110

Solution processed metallic nanowire based transparent electrode capped with a multifunctional layer  

NASA Astrophysics Data System (ADS)

Solution processed metallic nanowires (NWs) have been attracting increasing attention because of the effective combination of electrical and optical properties. However, they still suffer from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to the substrate. These factors need to be addressed for the wide-spread use of metallic NWs as transparent electrodes. In this work, we demonstrate that by using a solution processed zinc oxide (ZnO) capping layer, NW films show improved electro-optical properties, adhesion, and mechanical flexibility. In addition, the ZnO film reduces the surface roughness by more than half of its initial value, provides protection against oxidation, coalescence at high temperature, damp-heat conditions, and even extreme chemical environments.

Ghosh, D. S.; Chen, T. L.; Mkhitaryan, V.; Formica, N.; Pruneri, V.

2013-06-01

111

Metal-Free Graphene as Transparent Electrode for GaN-Based Light-Emitters  

NASA Astrophysics Data System (ADS)

Graphene contacts to p-GaN are considered as an alternative to indium--tin-oxide transparent electrodes in GaN based vertical-cavity surface-emitting lasers (VCSELs). Contact properties were investigated on light-emitting diode and p-GaN test structures, where dielectric apertures were used to eliminate the influence of the metal pads used to bias the contacts. Using single layer graphene we were able to operate light emitting diodes with current densities of 300 A/cm2. Addition of a second layer of graphene increased the maximum bias current to 1 kA/cm2. However, the contacts are non-linear and cannot withstand high current densities for a long time. The results are promising but further investigation and improvement is needed for graphene to be a viable alternative to indium--tin-oxide for blue VCSELs.

Stattin, Martin; Rosa, Cesar Lockhart de la; Sun, Jie; Yurgens, August; Haglund, Åsa

2013-08-01

112

Equivalent circuit modeling of metal-semiconductor-metal photodiodes with transparent conductor electrodes  

NASA Astrophysics Data System (ADS)

Metal-semiconductor-metal (MSM) photodiodes with electrodes fabricated from the transparent conductor cadmium tin oxide (CTO) have been shown to double photoresponsivity. Their bandwidths, however, are significantly lower than those of MSMs fabricated with standard Ti/Au contacts. Though MSMs are generally believed to be limited by the transit time of electrons, it is possible the larger resistivity of CTO has become a significant factor, making the MSMs RC time constant limited instead. Previous models of MSMs only account for one of the two back-to-back Schottky diodes. A new model which takes into account both the forward and reverse biased junctions has been developed from the small signal model of a Schottky diode. This new model was fit to data obtained from S-parameter measurements, and incorporates both the transit time response and RC time constant response.

Rommel, Sean L.; Erby, David N.; Gao, Wei; Berger, Paul R.; Zydzik, George J.; Rhodes, W. W.; O'Bryan, H. M.; Sivco, Deborah L.; Cho, Alfred Y.

1997-04-01

113

Low-temperature self-assembled vertically aligned carbon nanofibers as counter-electrode material for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

Low-temperature AC–DC PECVD is employed for direct growth of vertically aligned carbon nanofibers (VACNFs) on ordinary transparent conductive glass as counter-electrode material for dye-sensitized solar cells (DSSCs). To the best of our knowledge, this is the first report on utilization of VACNFs grown directly on ordinary FTO-coated glass as a cost-effective catalyst material in DSSCs. According to the FESEM images, the as-grown arrays are well aligned and dense, and offer uniform coverage on the surface of the substrate. In-plane and out-of-plane conductivity measurements reveal their good electrical conductivity, and Raman spectroscopy suggests a high number of electrocatalytic active sites, favoring charge transport at the electrolyte/electrode interface. Hybrid VACNF/Pt electrodes are also fabricated for performance comparison with Pt and VACNF electrodes. X-ray diffraction results verify the crystallization of Pt in hybrid electrodes and further confirm the vertical alignment of carbon nanofibers. Electrochemical characterization indicates that VACNFs provide both high catalytic and good charge transfer capability, which can be attributed to their high surface area, defect-rich and one-dimensional structure, vertical alignment and low contact resistance. As a result, VACNF cells can achieve a comparable performance (?5.6%) to that of the reference Pt cells (?6.5%). Moreover, by combination of the excellent charge transport and catalytic ability of VACNFs and the high conductivity of Pt nanoparticles, hybrid VACNF/Pt cells can deliver a performance superior to that of the Pt cells (?7.2%), despite having a much smaller amount of Pt loading, which raises hopes for low-cost large-scale production of DSSCs in the future.

Mahpeykar, S. M.; Tabatabaei, M. K.; Ghafoori-fard, H.; Habibiyan, H.; Koohsorkhi, J.

2013-11-01

114

Low-temperature self-assembled vertically aligned carbon nanofibers as counter-electrode material for dye-sensitized solar cells.  

PubMed

Low-temperature AC-DC PECVD is employed for direct growth of vertically aligned carbon nanofibers (VACNFs) on ordinary transparent conductive glass as counter-electrode material for dye-sensitized solar cells (DSSCs). To the best of our knowledge, this is the first report on utilization of VACNFs grown directly on ordinary FTO-coated glass as a cost-effective catalyst material in DSSCs. According to the FESEM images, the as-grown arrays are well aligned and dense, and offer uniform coverage on the surface of the substrate. In-plane and out-of-plane conductivity measurements reveal their good electrical conductivity, and Raman spectroscopy suggests a high number of electrocatalytic active sites, favoring charge transport at the electrolyte/electrode interface. Hybrid VACNF/Pt electrodes are also fabricated for performance comparison with Pt and VACNF electrodes. X-ray diffraction results verify the crystallization of Pt in hybrid electrodes and further confirm the vertical alignment of carbon nanofibers. Electrochemical characterization indicates that VACNFs provide both high catalytic and good charge transfer capability, which can be attributed to their high surface area, defect-rich and one-dimensional structure, vertical alignment and low contact resistance. As a result, VACNF cells can achieve a comparable performance (?5.6%) to that of the reference Pt cells (?6.5%). Moreover, by combination of the excellent charge transport and catalytic ability of VACNFs and the high conductivity of Pt nanoparticles, hybrid VACNF/Pt cells can deliver a performance superior to that of the Pt cells (?7.2%), despite having a much smaller amount of Pt loading, which raises hopes for low-cost large-scale production of DSSCs in the future. PMID:24107390

Mahpeykar, S M; Tabatabaei, M K; Ghafoori-Fard, H; Habibiyan, H; Koohsorkhi, J

2013-10-09

115

Monolithic quasi-solid-state dye-sensitized solar cells based on graphene modified mesoscopic carbon counter electrodes  

NASA Astrophysics Data System (ADS)

We have developed a monolithic quasi-solid-state dye-sensitized solar cell (DSSC) based on graphene modified mesoscopic carbon counter electrode (GC-CE), which offers a promising prospect for commercial applications. Based on the design of a triple layer structure, the TiO2 working electrode layer, ZrO2 spacer layer and carbon counter electrode (CE) layer are constructed on a single conducting glass substrate by screen-printing. The quasi-solid-state polymer gel electrolyte employs a polymer composite as the gelator and could effectively infiltrate into the porous layers. Fabricated with normal carbon counter electrode (NC-CE) containing graphite and carbon black, the device shows a power conversion efficiency (PCE) of 5.09% with the fill factor (FF) of 0.63 at 100 mW cm-2 AM1.5 illumination. When the NC-CE is modified with graphene sheets, the PCE and FF could be enhanced to 6.27% and 0.71, respectively. This improvement indicates excellent conductivity and high electrocatalytic activity of the graphene sheets, which have been considered as a promising platinum-free electrode material for DSSCs.

Rong, Yaoguang; Li, Xiong; Liu, Guanghui; Wang, Heng; Ku, Zhiliang; Xu, Mi; Liu, Linfeng; Hu, Min; Yang, Ying; Han, Hongwei

2013-03-01

116

Monolithic quasi-solid-state dye-sensitized solar cells based on graphene-modified mesoscopic carbon-counter electrodes  

NASA Astrophysics Data System (ADS)

A monolithic quasi-solid-state dye-sensitized solar cell (DSSC) based on graphene-modified mesoscopic carbon-counter electrode is developed. A TiO2-working electrode layer, ZrO2 spacer layer, and carbon counter electrode layer were constructed on a single conducting glass substrate by screen printing. The quasi-solid-state polymer gel electrolyte employed a polymer composite as the gelator, and effectively infiltrated the porous layers. Fabricated with normal carbon-counter electrode (NC-CE) containing graphite and carbon black, the DSSC had a power conversion efficiency (PCE) of 5.09% with the fill factor of 0.63 at 100 mW cm-2 AM1.5 illumination. When the NC-CE was modified with graphene sheets, the PCE and fill factor were enhanced to 6.27% and 0.71, respectively. This improvement indicates excellent conductivity and high electrocatalytic activity of the graphene sheets, which have been considered as a promising platinum-free electrode material for DSSCs.

Rong, Yaoguang; Han, Hongwei

2013-01-01

117

Transparent, highly conductive graphene electrodes from acetylene-assisted thermolysis of graphite oxide sheets and nanographene molecules  

NASA Astrophysics Data System (ADS)

Transparent and highly conductive graphene electrodes have been fabricated through acetylene-assisted thermolysis of graphite oxide (GO) sheets. This novel procedure uses acetylene as a supplemental carbon source to repair substantial defects within GO sheets, leading to the enhancement of graphitization of synthesized graphene electrodes. The as-prepared graphene on quartz substrates exhibits an electrical conductivity of 1425 S cm-1 with an optical transmittance of more than 70% at a wavelength of 500 nm. Such an acetylene-assisted thermal treatment approach is also adopted to fabricate graphene electrodes from synthetic nanographene molecules, with an almost five times increase in conductivity compared to samples prepared by the common thermal reduction.

Liang, Yanyu; Frisch, Johannes; Zhi, Linjie; Norouzi-Arasi, Hassan; Feng, Xinliang; Rabe, Jürgen P.; Koch, Norbert; Müllen, Klaus

2009-10-01

118

Flexible organic light-emitting diodes with transparent carbon nanotube electrodes: problems and solutions.  

PubMed

We study in detail here the application of transparent, conductive carbon single-wall nanotube (SWNT) networks as electrodes in flexible organic light-emitting diodes (FOLEDs). Overall comparisons of these networks to the commonly used electrodes poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and indium tin oxide (ITO) are made, and SWNT networks are shown to have excellent optical and superior mechanical properties. The effects of protruding nanotubes, rough surface morphology, and SWNT network-adjacent layer dewetting are shown to be problematic, and approaches for addressing these issues are identified. The mechanical properties of SWNT networks and ITO are compared, and SWNT networks are shown to exhibit more durable sheet conductance under bending, which leads to bendable FOLEDs. We demonstrated FOLEDs with SWNT network anodes that exhibit outstanding light output and meet display requirements. SWNT-based FOLEDs show comparable lifetime performances to ITO-based devices. The promise and the remaining challenges for implementing SWNT networks in organic light-emitting diodes are discussed. PMID:20332557

Hu, Liangbing; Li, Jianfeng; Liu, Jun; Grüner, George; Marks, Tobin

2010-03-23

119

Transparent Conducting Nb-Doped TiO2 Electrodes Activated by Laser Annealing for Inexpensive Flexible Organic Solar Cells  

NASA Astrophysics Data System (ADS)

A KrF excimer laser (? = 248 nm) has been adopted for annealing cost-effective Nb-doped TiO2 (NTO) films. Sputtered NTO layers were annealed on SiO2-coated flexible poly(ethylene terephthalate) (PET) substrates. This local laser annealing technique is very useful for the formation of anatase NTO electrodes used in flexible organic solar cells (OSCs). An amorphous NTO film with a high resistivity and a low transparency was transformed significantly into a conductive and transparent anatase NTO electrode by laser irradiation. The 210 nm anatase NTO film shows a sheet resistance of 50 ? and an average optical transmittance of 83.5% in the wavelength range from 450 to 600 nm after annealing at 0.25 J/cm2. The activation of Nb dopants and the formation of the anatase phase contribute to the high conductivity of the laser-annealed NTO electrode. Nb activation causes an increase in the optical band gap due to the Burstein--Moss effect. The electrical properties are in agreement with the material characteristics determined by X-ray diffraction (XRD) analysis and secondary ion mass spectrometry (SIMS). The irradiation energy for the NTO electrode also affects the performance of the organic solar cell. The laser annealing technique provides good properties of the anatase NTO film used as a transparent electrode for flexible organic solar cells (OSCs) without damage to the PET substrate or layer delamination from the substrate.

Lee, Jung-Hsiang; Lin, Chia-Chi; Lin, Yi-Chang

2012-01-01

120

Large-size, high-uniformity, random silver nanowire networks as transparent electrodes for crystalline silicon wafer solar cells.  

PubMed

Metal nanowire networks are emerging as next generation transparent electrodes for photovoltaic devices. We demonstrate the application of random silver nanowire networks as the top electrode on crystalline silicon wafer solar cells. The dependence of transmittance and sheet resistance on the surface coverage is measured. Superior optical and electrical properties are observed due to the large-size, highly-uniform nature of these networks. When applying the nanowire networks on the solar cells with an optimized two-step annealing process, we achieved as large as 19% enhancement on the energy conversion efficiency. The detailed analysis reveals that the enhancement is mainly caused by the improved electrical properties of the solar cells due to the silver nanowire networks. Our result reveals that this technology is a promising alternative transparent electrode technology for crystalline silicon wafer solar cells. PMID:24104422

Xie, Shouyi; Ouyang, Zi; Jia, Baohua; Gu, Min

2013-05-01

121

Morphological and opto-electrical properties of a solution deposited platinum counter electrode for low cost dye sensitized solar cells.  

PubMed

Although platinum (Pt) is a rare and very expensive material, Pt counter electrodes are still very commonly used for reaching high efficiencies in dye-sensitized solar cells (DSCs). The use of alternative cheaper catalyst materials did not yet yield equivalent efficiencies. In this work, we tried to understand how to reduce the amount of deposited Pt-material and simultaneously deliver higher DSC performances. We systematically compared the properties of Pt-counter electrodes prepared by simple solution deposition methods such as spray-coating, dip-coating, brushing with reference to the Pt-electrodes prepared by sputtering onto fluorine doped-tin oxides (FTOs). The morphological and structural characterizations of the deposited Pt-layers were performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The composition of Pt-material was quantified using SEM electron dispersive X-ray (EDX) mapping measurements which were further compared with optical transmission measurements. Also contact angle and sheet resistance measurements were performed. By taking Pt-layers composition, morphology and structural factors into account, 9.16% efficient N3 dye based DSCs were assembled. The DSCs were subjected to various opto-electrical characterization techniques like current-voltage (I-V), external quantum efficiency (EQE), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and transient photo voltage (TPV) measurements. The obtained experimental data suggest that the Pt counter electrodes prepared by solution deposition methods can also reach high DSC device performances with a consumption of very little amount of Pt material as compared with sputtered Pt-layers. This process also proves that higher DSC performances are not limited to the usage of sputtered Pt-layer as counter electrode. PMID:24146075

Thalluri, Gopala Krishna V V; Décultot, Marc; Henrist, Catherine; Dewalque, Jennifer; Colson, Pierre; Habraken, Serge; Spoltore, Donato; Manca, Jean; Cloots, Rudi

2013-10-21

122

Preparation of flexible organic solar cells with highly conductive and transparent metal-oxide multilayer electrodes based on silver oxide.  

PubMed

We report that significantly more transparent yet comparably conductive AgOx films, when compared to Ag films, are synthesized by the inclusion of a remarkably small amount of oxygen (i.e., 2 or 3 atom %) in thin Ag films. An 8 nm thick AgOx (O/Ag = 2.4 atom %) film embedded between 30 nm thick ITO films (ITO/AgOx/ITO) achieves a transmittance improvement of 30% when compared to a conventional ITO/Ag/ITO electrode with the same configuration by retaining the sheet resistance in the range of 10-20 ? sq(-1). The high transmittance provides an excellent opportunity to improve the power-conversion efficiency of organic solar cells (OSCs) by successfully matching the transmittance spectral range of the electrode to the optimal absorption region of low band gap photoactive polymers, which is highly limited in OSCs utilizing conventional ITO/Ag/ITO electrodes. An improvement of the power-conversion efficiency from 4.72 to 5.88% is achieved from highly flexible organic solar cells (OSCs) fabricated on poly(ethylene terephthalate) polymer substrates by replacing the conventional ITO/Ag/ITO electrode with the ITO/AgOx/ITO electrode. This novel transparent electrode can facilitate a cost-effective, high-throughput, room-temperature fabrication solution for producing large-area flexible OSCs on heat-sensitive polymer substrates with excellent power-conversion efficiencies. PMID:24060352

Yun, Jungheum; Wang, Wei; Bae, Tae Sung; Park, Yeon Hyun; Kang, Yong-Cheol; Kim, Dong-Ho; Lee, Sunghun; Lee, Gun-Hwan; Song, Myungkwan; Kang, Jae-Wook

2013-10-04

123

Platinum-graphene counter electrodes for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

This paper describes the photovoltaic performance of dye-sensitized solar cells (DSSCs) containing graphene-incorporated counter electrodes (CEs). The location and thickness of graphene in CEs are optimized to improve the photovoltaic performance of DSSCs, compared with typical Pt CEs. The DSSC, with a Pt/few-layer graphene (FLG) CE, achieved 8% in short-circuit current density and 13% in power conversion efficiency (PCE). Electrochemical impedance spectroscopy shows that the DSSC, with a Pt/FLG CE, exhibits a series resistance lower than that with a Pt CE. The lower series resistance is attributed to the contact resistance at the interface of platinum and fluorine doped tin oxide. The contact resistance is reduced by the formation of the thin platinum-carbon composite layer. It is demonstrated that the consumption of Pt could be reduced with a Pt/FLG CE. However, graphene/Pt CEs resulted in a slow charge-transfer process and consequently a worse photovoltaic performance of DSSCs.

Cheng, Cheng-En; Lin, Chi-Yuan; Shan, Chien-Hsun; Tsai, Shang-Yi; Lin, Ko-Wei; Chang, Chen-Shiung; Shih-Sen Chien, Forest

2013-07-01

124

Long-wavelength metal-semiconductor-metal photodetectors with transparent and opaque electrodes  

NASA Astrophysics Data System (ADS)

In this paper, we present a comparative study of transparent and opaque electrode InAlAs/InGaAs metal-semiconductor-metal photodiodes (MSMPDs) for operation at 1.31 and 1.55 micrometers . The transparent materials are indium-tin-oxide (ITO) and cadmium-tin-oxide (CTO) and the opaque material is Ti-Au. The rf magnetron sputtered films of ITO and CTO, deposited at a substrate temperature of 300 degrees C, exhibited as-deposited resistivities of 5.6(DOT)10-3 (Omega) (DOT)cm and 1.0(DOT)10-3 (Omega) (DOT)cm, respectively. The resistivity of the ITO and CTO films dropped to 1.1(DOT)10-3 (Omega) (DOT)cm and 5.2(DOT)10-4 (Omega) (DOT)cm, respectively, after a 4 minute 400 degree C anneal in an N2 ambient. The interdigitated ITO and CTO electrodes were made by etching in a methane:hydrogen (1 to 3) plasma. The responsivity of 1 micrometers finger by 1 micrometers spacing (1 by 1 micrometers ), 50 X 50 micrometers 2 active area, MSMPDs was 0.40 A/W for the Ti-Au, 0.66 A/W for the CTO, and 0.69 A/W for the ITO MSMPDs. The Ti-Au, CTO and ITO MSMPDs had 3- dB cut-off frequencies of 14.0 GHz, 7.5 GHz, and 5.0 GHz, respectively, from time-domain measurements performed at 1.3 micrometers and 11.26 GHz, 4.00 GHz, and 2.61 GHz, respectively, from frequency-domain measurements performed at 1.55 micrometers . Discrepencies between the 3-dB cut-off frequency obtained from the time-domain and the frequency-domain measurements are attributed to the time-domain measurement system's inability to accurately resolve low frequency behavior (below 2 GHz) and space charge effects.

Wohlmuth, Walter A.; Adesida, Ilesanmi; Caneau, Catherine

1995-09-01

125

Great improvement of catalytic activity of oxide counter electrodes fabricated in N2 atmosphere for dye-sensitized solar cells.  

PubMed

The dye-sensitized solar cells (DSCs) using SnO(2) and Nb(2)O(5) counter electrodes (CEs) prepared in N(2) atmosphere yielded power conversion efficiencies (PCE) of 6.09% and 4.65%, much higher than the PCE values (1.84%, 0.97%) of the DSCs using the same SnO(2) and Nb(2)O(5) CEs prepared in air. PMID:23282677

Wu, Mingxing; Lin, Xiao; Guo, Wei; Wang, Yudi; Chu, Lingling; Ma, Tingli; Wu, Kezhong

2013-02-01

126

Pyrolytic carbon from an aromatic precursor and its application as a counter electrode in dye-sensitized solar cells.  

PubMed

Pyrolytic carbon thin films were deposited on quartz plates through a chemical vapor deposition process, by using a biphenyl precursor, 4,4'-bis(chloromethyl-1,1'-biphenyl). The pyrolytic carbons were microporous and catalytic toward reduction of tri-iodide, and the films thus obtained possessed a metallic appearance with good mirror reflections, hydrophilic surfaces, and low sheet resistances. The pyrolytic carbon-coated quartz plates were used, in place of the commonly used Pt-coated fluorine-doped tin oxide glass, as the counter electrode for dye-sensitized solar cells (DSSCs). The light to electricity conversion efficiency of the cell thus obtained was reasonably high, achieving 78% of that obtained by using the conventional but much more expensive Pt counter electrode. From the electrochemical impedance spectroscopic analysis, one found that the minor reduction in the conversion efficiency came from the relatively higher resistance and lower catalytic activity of the pyrolytic carbon. This work demonstrates that the newly developed pyrolytic carbon films may be a promising alternative to Pt as the counter electrode material for DSSCs. PMID:21243704

Hsiao, Chang-Tao; Lu, Shih-Yuan; Tsai, Tsung-Yu

2010-11-25

127

Modification of carbon nanotube transparent conducting films for electrodes in organic light-emitting diodes  

NASA Astrophysics Data System (ADS)

Single-walled carbon nanotube (SWCNT) transparent conducting films (TCFs) were fabricated for the electrodes of organic light-emitting diodes (OLEDs); three types of film were studied. The as-prepared SWCNT TCFs displayed a relatively low sheet resistance of 82.6 ?/sq at 80.7 T% with a relatively large surface roughness of 30 nm. The TCFs were top-coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) to obtain PEDOT:PSS-coated TCFs. The PEDOT:PSS cover improved the conductivity and decreased the surface roughness to 12 nm at the cost of film transmittance. The SWCNT TCFs mixed with PEDOT:PSS (PM-TCFs) exhibited a high conductivity (70.6 ?/sq at 81 T%) and a low surface roughness (3 nm) and were thus selected as the best TCFs for OLEDs. Blue flexible OLEDs with 4,4?-bis(2,2?-diphenylvinyl)-1,1?-biphenyl (Dpvbi) as the emitting layer were fabricated on TCFs with the same structures to evaluate the performances of the different types of SWCNT films for use in OLEDs. Of these three types of OLEDs, the PM-TCF devices exhibited the optimal performance with a maximum luminance of 2587 cd m-2 and a current efficiency of 5.44 cd A-1. This result was explored using field-emission scanning electron microscopy and atomic force microscopy to further study the mechanisms that are involved in applying SWCNT TCFs to OLEDs.

Gao, Jing; Mu, Xue; Li, Xiao-Yun; Wang, Wen-Yi; Meng, Yan; Xu, Xiao-Bing; Chen, Li-Ting; Cui, Li-Jun; Wu, Xiaoming; Geng, Hong-Zhang

2013-11-01

128

Control of thickness uniformity and grain size in graphene films for transparent conductive electrodes.  

PubMed

Large-scale and transferable graphene films grown on metal substrates by chemical vapor deposition (CVD) still hold great promise for future nanotechnology. To realize the promise, one of the key issues is to further improve the quality of graphene, e.g., uniform thickness, large grain size, and low defects. Here we grow graphene films on Cu foils by CVD at ambient pressure, and study the graphene nucleation and growth processes under different concentrations of carbon precursor. On the basis of the results, we develop a two-step ambient pressure CVD process to synthesize continuous single-layer graphene films with large grain size (up to hundreds of square micrometers). Scanning electron microscopy and Raman spectroscopy characterizations confirm the film thickness and uniformity. The transferred graphene films on cover glass slips show high electrical conductivity and high optical transmittance that make them suitable as transparent conductive electrodes. The growth mechanism of CVD graphene on Cu is also discussed, and a growth model has been proposed. Our results provide important guidance toward the synthesis of high quality uniform graphene films, and could offer a great driving force for graphene based applications. PMID:22173552

Wu, Wei; Yu, Qingkai; Peng, Peng; Liu, Zhihong; Bao, Jiming; Pei, Shin-Shem

2011-12-16

129

Fiber-optic polarization and phase modulator utilizing transparent piezofilm with indium tin oxide electrodes.  

PubMed

A highly efficient optical polarization and phase modulator formed by the placement of a thin transparent piezofilm with indium tin oxide electrodes directly in the path of the output from an optical fiber is presented. Various configurations that differ in the clamping conditions, utilization of epoxy, and optical arrangement are presented. For a film thickness of 63.9 µm, a linear phase-shifting coefficient of 0.131 rad/voltage peak (Vp) at 2 kHz and of 0.508 rad/Vp at 7.4 kHz is demonstrated. An intrinsic birefringence of 0.0328 between the directions along the stretch and its perpendicular in the plane of the film has been measured. The polarization modulation coefficient was determined to be 0.323 rad/Vp at 8.423 kHz, corresponding to a half-wave voltage of 8.353 Vp. Applications of the device involving concurrent spatiotemporal polarization and phase modulation are indicated. PMID:21037647

Sudarshanam, V S; Desu, S B

1995-03-01

130

Invisible metal-grid transparent electrode prepared by electrohydrodynamic (EHD) jet printing  

NASA Astrophysics Data System (ADS)

Invisible Ag-grid transparent electrodes (TEs) were prepared by electrohydrodynamic (EHD) jet printing using Ag nano-particle inks. Ag-grid width less than 10 µm was achieved by the EHD jet printing, which was invisible to the naked eye. The Ag-grid line-to-line distance (pitch) was modulated in order to investigate the electrical and optical properties of the EHD jet-printed Ag-grid TEs. The decrease in the sheet resistance at the expense of the transmittance was observed as the Ag-grid pitch decreased. The figure of merit of Ag-grid TEs with various Ag-grid pitches was investigated in order to determine the optimum pitch condition for both electrical and optical properties. With the 150 µm Ag-grid pitch, the EHD jet-printed Ag-grid TE has the sheet resistance of 4.87 ? sq-1 and the transmittance of 81.75% after annealing at 200 °C under near-infrared. Ag filling factor (FF) was defined to predict the electrical and optical properties of Ag-grid TEs. It was found that the measured electrical and optical properties were well simulated by the theoretical equations incorporating FF. The EHD jet-printed invisible Ag-grid TE with good electrical and optical properties implies its promising application to the printed optoelectronic devices.

Jang, Yonghee; Kim, Jihoon; Byun, Doyoung

2013-04-01

131

Hot spot engineering for light absorption enhancement of solar cells with a super-structured transparent conducting electrode  

NASA Astrophysics Data System (ADS)

We study the impact of a super-structuration of the transparent conducting electrode made of polycrystalline ZnO:Al on the efficiency of thin solar cells based on amorphous silicon. We demonstrate that photonic crystal cavities etched in the electrode present efficient anti-reflective properties and add absorption resonances in the red part of the spectrum where other structures are inefficient. This super-structuring boosts the optical absorption by 4.2% and broaden the angular acceptance compared to conventional grating patterns. The origin of these cavity states is explained in the framework of the envelop function approach.

Smaali, R.; Centeno, E.; Moreau, A.

2013-09-01

132

Application of Single Wall Carbon Nanotubes as Transparent Electrodes in Cu(In,Ga)Se2-Based Solar Cells: Preprint  

SciTech Connect

We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell results from devices made using CuIn1-xGaxSe2 thin-film absorber materials. Achieving an energy conversion efficiency of >12% and a quantum efficiency of {approx}80% demonstrate the feasibility of the concept. A discussion of the device structures will be presented considering the physical properties of the new electrodes comparing current-voltage results from the new solar cell structure and those from standard ZnO/CdS/Cu(In,Ga)Se2/Mo solar cells.

Contreras, M.; Barnes, T.; van de Lagemaat, J.; Rumbles, G.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.

2006-05-01

133

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

SciTech Connect

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

Gordon, R.G. [Harvard Univ., Cambridge, MA (United States)

1995-10-01

134

Highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites: Pt-free, highly efficient, and durable counter electrodes for dye-sensitized solar cells.  

PubMed

We report the preparation of highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites which show Pt-like dye-sensitized solar cell (DSSC) efficiency and remarkable long-term durability as DSSC counter electrodes. PMID:22499057

Jo, Yimhyun; Cheon, Jae Yeong; Yu, Jeonghun; Jeong, Hu Young; Han, Chi-Hwan; Jun, Yongseok; Joo, Sang Hoon

2012-04-12

135

Investigation on new CuInS2/carbon composite counter electrodes for CdS/CdSe cosensitized solar cells.  

PubMed

The search for semiconductor-sensitized solar cell (SSC) counter electrode alternatives has been a continuous effort and long ongoing work, while the studies in counter electrode kinetic performance and stability are important to improve the overall efficiency. Here, a ternary chalcopyrite compound CuInS2 is first employed as counter electrode (CE) material for CdS/CdSe cosensitized solar cells. Besides, in order to increase the electron transfer activity at the counter electrode/electrolyte interface and stability, an appropriate amount of active carbon/carbon black mixture is introduced to afford CuInS2/carbon composite electrodes. Electron transfer processes in CuInS2-based electrodes are investigated in detail with the aid of electrochemical impedance spectroscopy and I-E measurement. Up to 4.32% of the light-to-electricity conversion efficiency has been achieved for the CdS/CdSe SSCs with the CuInS2/carbon composite electrode. Besides, a preliminary long-term stability test reveals that the new CuInS2/carbon composite counter electrode exhibits good stability after being kept in the dark at room temperature and without current flow for 1000 h. PMID:23734873

Zhang, Xiaolu; Huang, Xiaoming; Yang, Yueyong; Wang, Shen; Gong, Yun; Luo, Yanhong; Li, Dongmei; Meng, Qingbo

2013-06-26

136

Simple method for manufacturing Pt counter electrodes on conductive plastic substrates for dye-sensitized solar cells.  

PubMed

A novel, facile, and low-cost method was developed for manufacturing Pt counter electrodes (CEs) of dye-sensitized solar cells (DSCs) on the indium tin oxide-coated polyethylene terephthalate (ITO-PET). This press-transferring method reconciled the temperature conflict between the sintering process of thermal decomposition of H(2)PtCl(6) and plastic substrates. Cyclic voltammograms, electrochemical impedance spectroscopy, transmittance spectra and photovoltaic performance were characterized to investigate the transferred Pt CEs. It was found that the transferred Pt CEs on ITO-PET exhibited an excellent catalytic activity comparable with traditional electrodes on FTO glasses. On the front-side, an illuminated conversion efficiency of 7.21% was reached with more than 94% efficiency of conventional thermally deposited Pt CEs on FTO glasses, and on the back-side, the illuminated conversion efficiency was 4.86%, which was higher than that for conventional electrodes. PMID:23298312

Gong, Yun; Li, Chunhui; Huang, Xiaoming; Luo, Yanhong; Li, Dongmei; Meng, Qingbo; Iversen, Bo Brummerstedt

2013-01-17

137

Optimization of Transparent Electrode for Solar Cell and Chemical Vapor Deposition of Amorphous Silicon. Final Technical Report, 15 September 1980-30 March 1983.  

National Technical Information Service (NTIS)

A film of fluorine-doped tin oxide can meet all these requirements. A new process for depositing fluorine-doped tin oxide films was optimized. Further optimization of the transparent electrode films has been accomplished, with increasing substrate tempera...

R. G. Gordon J. Proscia F. Ellis S. Kurtz

1983-01-01

138

Modification of carbon nanotube transparent conducting films for electrodes in organic light-emitting diodes.  

PubMed

Single-walled carbon nanotube (SWCNT) transparent conducting films (TCFs) were fabricated for the electrodes of organic light-emitting diodes (OLEDs); three types of film were studied. The as-prepared SWCNT TCFs displayed a relatively low sheet resistance of 82.6 ?/sq at 80.7 T% with a relatively large surface roughness of 30 nm. The TCFs were top-coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) to obtain PEDOT:PSS-coated TCFs. The PEDOT:PSS cover improved the conductivity and decreased the surface roughness to 12 nm at the cost of film transmittance. The SWCNT TCFs mixed with PEDOT:PSS (PM-TCFs) exhibited a high conductivity (70.6 ?/sq at 81 T%) and a low surface roughness (3 nm) and were thus selected as the best TCFs for OLEDs. Blue flexible OLEDs with 4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (Dpvbi) as the emitting layer were fabricated on TCFs with the same structures to evaluate the performances of the different types of SWCNT films for use in OLEDs. Of these three types of OLEDs, the PM-TCF devices exhibited the optimal performance with a maximum luminance of 2587 cd m(-2) and a current efficiency of 5.44 cd A(-1). This result was explored using field-emission scanning electron microscopy and atomic force microscopy to further study the mechanisms that are involved in applying SWCNT TCFs to OLEDs. PMID:24084604

Gao, Jing; Mu, Xue; Li, Xiao-Yun; Wang, Wen-Yi; Meng, Yan; Xu, Xiao-Bing; Chen, Li-Ting; Cui, Li-Jun; Wu, Xiaoming; Geng, Hong-Zhang

2013-10-02

139

Transparent organic thin film transistors with WO3/Ag/WO3 source-drain electrodes fabricated by thermal evaporation  

NASA Astrophysics Data System (ADS)

High-performance transparent organic thin film transistors using a WO3/Ag/WO3 (WAW) multilayer as the source and drain electrodes have been developed without breaking the vacuum. The WAW electrodes were deposited by thermal evaporation at room temperature, leading to little damage to organic film. The optimized WAW electrode shows high transmittance (86.57%), low sheet resistance (11 ?/sq), and a high work function (5.0 eV). Consequently, we obtained high performance devices with mobility of 8.44 × 10-2 cm2/V . s, an on/off ratio of approximately 1.2 × 106, and an average visible range transmittance of 81.5%.

Zhang, Nan; Hu, Yongsheng; Liu, Xingyuan

2013-07-01

140

Transparent, highly conductive graphene electrodes from acetylene-assisted thermolysis of graphite oxide sheets and nanographene molecules.  

PubMed

Transparent and highly conductive graphene electrodes have been fabricated through acetylene-assisted thermolysis of graphite oxide (GO) sheets. This novel procedure uses acetylene as a supplemental carbon source to repair substantial defects within GO sheets, leading to the enhancement of graphitization of synthesized graphene electrodes. The as-prepared graphene on quartz substrates exhibits an electrical conductivity of 1425 S cm(-1) with an optical transmittance of more than 70% at a wavelength of 500 nm. Such an acetylene-assisted thermal treatment approach is also adopted to fabricate graphene electrodes from synthetic nanographene molecules, with an almost five times increase in conductivity compared to samples prepared by the common thermal reduction. PMID:19801755

Liang, Yanyu; Frisch, Johannes; Zhi, Linjie; Norouzi-Arasi, Hassan; Feng, Xinliang; Rabe, Jürgen P; Koch, Norbert; Müllen, Klaus

2009-10-02

141

Evaluation of surface control and durability CNT and ITO coated PET transparent electrode under different dry conditions  

NASA Astrophysics Data System (ADS)

Transparent electrodes using carbon nanotube (CNT) have recently been studied as potential replacements for convention ITO. In this work, CNT or ITO coated polyethylene terephthalate (PET) samples were prepared and studied. The degree of cohesion is dependent on the drying conditions. To explore effects of changing surface conditions, three drying temperatures, 20 °C, 80 °C, and 120 °C, were used. Electrical resistance measures were used to evaluate the interfacial durability and electrical properties of prepared transparent electrodes. FE-SEM was used to investigate surface changes and UV-spectroscopy was used to evaluate transparency as functions of the different drying temperatures. The electronic properties for these nanoparticle coated surfaces were evaluated using a cyclic voltametry method. Interfacial durability was evaluated by static contact angle measurement changes with elapsed time. The pH values of the coatings were measured in a water solution. The durability of the CNT coated surfaces was found to be better than that of the ITO coated surfaces. The higher drying temperatures were found to produce better surfaces because of improved cohesion between the nanoparticles which resulted in improved electrical properties and improved durability of the coated surfaces.

Park, Joung-Man; Kwon, Dong-Jun; Wang, Zuo-Jia; Gu, Ga-Young; Devries, Lawrence

2012-02-01

142

Highly efficient telluride electrocatalysts for use as Pt-free counter electrodes in dye-sensitized solar cells.  

PubMed

Two transition metal tellurides, CoTe and NiTe2, were synthesized and for the first time employed as the counter electrodes (CEs) with high catalytic activity for reduction of I3(-) in dye-sensitized solar cells (DSCs). Using CoTe and NiTe2-based CEs, photoelectric conversion efficiencies (PCEs) of 6.92% and 7.21% were achieved for DSCs, respectively, comparable to that of 7.04% achieved when using a Pt-based CE. The results indicated that, serving as a CE in DSCs, telluride could be a cost-effective and efficient alternative to the noble metal Pt. PMID:24048371

Guo, Jiahao; Shi, Yantao; Chu, Yuting; Ma, Tingli

2013-10-01

143

Electrochemical, Optical and Electronic Properties of Iridium Tin Oxide Thin Film as Counter Electrode of Electrochromic Device  

NASA Astrophysics Data System (ADS)

Iridium tin oxide films (IRTOFs) containing dispersed iridium oxide in a tin oxide matrix were prepared by an ion-plating process. The optical, electrochemical, and electronic properties of the films were measured by varying the iridium concentration in the films. The cyclic voltammogram characteristic of the films showed good reproducibility. The coloration efficiency of the IRTOFs increased with an increase in the concentration of iridium. The change ranges of the conductivity become more than 108 times. The activation energy increased with increasing iridium concentration in the iridium concentration range in which the conductivity decreased. The characteristics of an all-solid-state electrochromic device with an IRTOF counter electrode were measured.

Niwa, Tatsuo; Takai, Osamu

2010-10-01

144

Ordered multimodal porous carbon as highly efficient counter electrodes in dye-sensitized and quantum-dot solar cells.  

PubMed

Ordered multimodal porous carbon (OMPC) was explored as a counter electrode in ruthenium complex dye-sensitized solar cells (DSSCs) and CdSe quantum-dot solar cells (QDSCs). The unique structural characteristics such as large surface area and well-developed three-dimensional (3-D) interconnected ordered macropore framework with open mesopores embedded in the macropore walls make the OMPC electrodes have high catalytic activities and fast mass transfer kinetics toward both triiodide/iodide and polysulfide electrolytes. The efficiency (ca. 8.67%) of the OMPC based DSSC is close to that (ca. 9.34%) of the Pt based one. Most importantly, the QDSC employing OMPC material presents a high efficiency of up to 4.36%, which is significantly higher than those of Pt- and activated carbon based solar cells, ca. 2.29% and 3.30%, respectively. PMID:20695615

Fan, Sheng-Qiang; Fang, Baizeng; Kim, Jung Ho; Jeong, Banseok; Kim, Chulwoo; Yu, Jong-Sung; Ko, Jaejung

2010-08-17

145

Transparent Conductive Oxide Layer-Less Three Dimensional Dye Sensitized Solar Cells: Fabrication of Ionic Path in Three Dimensional Ti Electrode  

NASA Astrophysics Data System (ADS)

A transparent conductive oxide-less dye-sensitized solar cell (TCO-less DSC) consisting of a thick and porous Ti electrode is reported. The Ti electrode was contacted with the back of a stained porous titania layer. A thick Ti electrode prepared by conventional sputtering prevented ionic diffusions through the Ti electrode and decreased photovoltaic performance. Tetrapod-shaped ZnO crystals were used to prepare straight and continuous nanopores in the Ti electrode to maintain the ionic diffusion. 8% efficiency of the TCO-less DSC is also reported.

Beppu, Takayuki; Kashiwa, Yohei; Hayase, Shuzi; Kono, Mitsuru; Yamaguchi, Yoshihiro

2009-06-01

146

The fabrication of GaN-based nanorod light-emitting diodes with multilayer graphene transparent electrodes  

NASA Astrophysics Data System (ADS)

GaN-based nanorod light-emitting diodes (LEDs) with multilayer graphene (MLG) transparent electrodes have been fabricated. Two types of nano-LEDs with graphene on and under the metal pads are fabricated and their performances are investigated. And LEDs with graphene on the metal-pads exhibiting lower forward voltage and higher electroluminescence intensity are obtained. Using scanning electron microscope and Raman spectroscopy, we have demonstrated that graphene transferred after the metal deposition remains intact and has much less damages than graphene under the metal during the fabrication of LEDs with nanorods.

Li, Zhi; Kang, Junjie; Zhang, Yiyun; Liu, Zhiqiang; Wang, Liancheng; Lee, Xiao; Li, Xiao; Yi, Xiaoyan; Zhu, Hongwei; Wang, Guohong

2013-06-01

147

A graphene sheet exfoliated with microwave irradiation and interlinked by carbon nanotubes for high-performance transparent flexible electrodes.  

PubMed

High quality graphene was obtained though microwave irradiated expansion following a solution process. This method is facile, inexpensive, and produces usable results. Ultrathin, uniform graphene films were fabricated at room temperature by a vacuum filtration method. Combining carbon nanotubes (CNTs) as bridges between graphene flakes allowed the fabrication of high-performance conductive films for flexible applications, with conductivities and optical properties comparable to commercial ITO: 181 Omega sq(-1) at 82.2% transmittance after chemical treatment and doping. With future work, this versatile material could well provide an appropriate transparent electrode for flexible optical electronics. PMID:20823496

Xin, Guoqing; Hwang, Wontae; Kim, Namhun; Cho, Sung M; Chae, Heeyeop

2010-09-08

148

Intrinsically stretchable transparent electrodes based on silver-nanowire–crosslinked-polyacrylate composites  

Microsoft Academic Search

Stretchable transparent composites have been synthesized consisting of a silver nanowire (AgNW) network embedded in the surface layer of a crosslinked poly(acrylate) matrix. The interpenetrating networks of AgNWs and the crosslinked polymer matrix lead to high surface conductivity, high transparency, and rubbery elasticity. The presence of carboxylic acid groups on the polymer chains enhances the bonding between AgNWs and the

Weili Hu; Xiaofan Niu; Lu Li; Sungryul Yun; Zhibin Yu; Qibing Pei

2012-01-01

149

Large scale pattern graphene electrode for high performance in transparent organic single crystal field-effect transistors.  

PubMed

High quality, large grain size graphene on polycrystalline nickel film on two inch silicon wafers was successfully synthesized by the chemical vapor deposition (CVD) method. The polydimethylsiloxane (PDMS) stamping method was used for graphene transferring in this experiment. The graphene transferred onto Al2O3/ITO substrates was patterned into macroscopic dimension electrodes using conventional lithography followed by oxygen plasma etching. Experimental results show that this graphene can serve as transparent source and drain electrodes in high performance organic semiconductor nanoribbon organic field-effect transistors (OFETs), facilitating high hole injection efficiency due to the preferred work function match with the channel material: single crystalline copper phthalocyanine (CuPc) nanoribbons. The nanoribbons were grown on top of the patterned graphene via evaporate-deposition to form the FET device. The carrier mobility and on/off current ratio of such devices were measured to be as high as 0.36 cm2/(V s) and 10(4). PMID:20536162

Liu, Wei; Jackson, Biyun Li; Zhu, Jing; Miao, Cong-Qin; Chung, Choong-Heui; Chung, Choon-Heui; Park, Young-Ju; Sun, Ke; Woo, Jason; Xie, Ya-Hong

2010-07-27

150

Room temperature flexible and transparent ITO/Ag/ITO electrode grown on flexile PES substrate by continuous roll-to-roll sputtering for flexible organic photovoltaics  

NASA Astrophysics Data System (ADS)

We prepared a flexible and transparent indium tin oxide (ITO)/Ag/ITO electrode on a polyethersulfone (PES) substrate using a specially designed roll-to-roll sputtering system at room temperature for use in flexible organic solar cells (OSCs). By the continuous roll-to-roll sputtering of the ITO and Ag targets, we fabricated a flexible ITO/Ag/ITO electrode with a sheet resistance (Rsh) of 4.28 ?/square, optical transmittance (T) of 89.28% and figure of merit value of 75.03 × 10-3 ?-1 at the optimized Ag thickness of 12 nm (dc power of 200 W) without breaking the vacuum, even though it was deposited at room temperature. The bending test results demonstrated that the ITO/Ag/ITO electrode has superior flexibility to the single ITO electrode, due to the high failure strain of the ductile Ag layer. Moreover, the flexible OSC fabricated on the optimized flexible ITO/Ag/ITO electrode showed an identical efficiency of 3.73% to the OSC fabricated on the commercial crystalline ITO electrode, due to its low sheet resistance and high transparency, which are well matched with the organic active layer. This indicates that the flexible ITO/Ag/ITO multilayer electrode grown by the continuous roll-to-roll sputtering technique is a promising flexible and transparent electrode for use in cost-efficient flexible OSCs.

Park, Yong-Seok; Choi, Kwang-Hyuk; Kim, Han-Ki

2009-12-01

151

In situ grown vertically oriented CuInS2 nanosheets and their high catalytic activity as counter electrodes in dye-sensitized solar cells.  

PubMed

Vertically oriented CuInS(2) nanosheet thin films were prepared via a facile one-step solvothermal process and used in dye-sensitized solar cells (DSSCs) as counter electrodes. The catalytic activity of the CuInS(2) films based on different precursor concentrations was investigated using electrochemical methods. DSSCs based on optimized CuInS(2) thin film as counter electrodes reached a power conversion efficiency of 6.33%, comparable to that of sputtering Pt (6.07%). PMID:23388681

Yang, Jie; Bao, Chunxiong; Zhang, Jiyuan; Yu, Tao; Huang, Huan; Wei, Yulong; Gao, Hao; Fu, Gao; Liu, Jianguo; Zou, Zhigang

2013-03-11

152

N-Doped graphene nanoplatelets as superior metal-free counter electrodes for organic dye-sensitized solar cells.  

PubMed

Highly efficient counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) were developed using thin films of scalable and high-quality, nitrogen-doped graphene nanoplatelets (NGnP), which was synthesized by a simple two-step reaction sequence. The resultant NGnP was deposited on fluorine-doped SnO2 (FTO)/glass substrates by using electrospray (e-spray) coating, and their electrocatalytic activities were systematically evaluated for Co(bpy)3(3+/2+) redox couple in DSSCs with an organic sensitizer. The e-sprayed NGnP thin films exhibited outstanding performances as CEs for DSSCs. The optimized NGnP electrode showed better electrochemical stability under prolonged cycling potential, and its Rct at the interface of the CE/electrolyte decreased down to 1.73 ? cm(2), a value much lower than that of the Pt electrode (3.15 ? cm(2)). The DSSC with the optimized NGnP-CE had a higher fill factor (FF, 74.2%) and a cell efficiency (9.05%), whereas those of the DSSC using Pt-CE were only 70.6% and 8.43%, respectively. To the best of our knowledge, the extraordinarily better current-voltage characteristics of the DSSC-NGnP outperforming the DSSC-Pt for the Co(bpy)3(3+/2+) redox couple (in paticular, FF and short circuit current, Jsc) is highlighted for the first time. PMID:23656316

Ju, Myung Jong; Kim, Jae Cheon; Choi, Hyun-Jung; Choi, In Taek; Kim, Sang Gyun; Lim, Kimin; Ko, Jaejung; Lee, Jae-Joon; Jeon, In-Yup; Baek, Jong-Beom; Kim, Hwan Kyu

2013-05-15

153

Indium tin oxide-free semi-transparent inverted polymer solar cells using conducting polymer as both bottom and top electrodes  

Microsoft Academic Search

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is investigated as a transparent cathode to replace indium tin oxide (ITO) in inverted polymer solar cells. Increasing the thickness of the PEDOT:PSS electrode leads to a reduction in transparency and sheet resistance which lowers the photocurrent but increases the fill factor of the solar cells. The offset of photocurrent and fill factor as the thickness is increased

Steven K. Hau; Hin-Lap Yip; Jingyu Zou; Alex K.-Y. Jen

2009-01-01

154

Amplified spontaneous emission in an organic semiconductor multilayer waveguide structure including a highly conductive transparent electrode  

NASA Astrophysics Data System (ADS)

We demonstrate that the amplified spontaneous emission (ASE) threshold in multilayer waveguide structures suitable for the use in future organic injection lasers can be drastically reduced by inserting a crosslinked hole transport layer (HTL) between a highly conductive indium tin oxide (ITO) electrode and the polymer emission layer. While no ASE is observed when the active layer material is directly spincoated onto the ITO electrode, it can be completely restored upon insertion of a 300-nm-thick HTL. This observation is attributed to reduced attenuation of the waveguided mode enabling the ASE process and is theoretically confirmed by calculations of the mode intensity fraction propagating in the absorptive ITO electrode.

Reufer, M.; Feldmann, J.; Rudati, P.; Ruhl, A.; Müller, D.; Meerholz, K.; Karnutsch, C.; Gerken, M.; Lemmer, U.

2005-05-01

155

Time resolved optical emission images of an atmospheric pressure plasma jet with transparent electrodes  

SciTech Connect

We study development of plasma packages in atmospheric pressure plasma jet from their formation as a discharge close to the instantaneous cathode, following their motion between and inside the electrodes up to their emergence at the edge of the glass tube and formation of a plasma bullet. Inside both electrodes, plasma is concentrated close to the walls and is bright, while outside it is located at the axis. This paper opens issues of the geometry of electrodes, fields, and atomic processes, allowing some predictions to be made about pertinent mechanisms.

Puac, N.; Maletic, D.; Lazovic, S.; Malovic, G.; Petrovic, Z. Lj. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Dordevic, A. [School of Electrical Engineering, University of Belgrade, Bul. kralja Aleksandra 73, 11000 Belgrade (Serbia)

2012-07-09

156

Optimization of transparent electrode for solar cell. Technical report, 15 September 1981-14 September 1982  

Microsoft Academic Search

Electrically conductive, transparent films of fluorine doped tin oxide have been investigated during this contract. These films were grown by the chemical vapor deposition from tetramethyl tin (TMT) in the presence of air and a freon (bromotrifluoromethane). In order to find the optimal conditions for growing high quality films, the concentrations of the reactants were varied, and the resulting film

R. G. Gordon; J. Proscia; F. Ellis; S. Kurtz

1982-01-01

157

Improving temperature-stable AZO-Ag-AZO multilayer transparent electrodes using thin Al layer modification  

NASA Astrophysics Data System (ADS)

The thermal stability of AZO/Al/Ag/Al/AZO (5A) compared with AZO/Ag/AZO (3A) electrodes was significantly improved by introducing a thin Al layer at the interface between Ag and AZO layers. The rapidly deteriorated sheet resistance of 3A compared with 5A electrodes is roughly consistent with the XRD results of weaker intensity of the (1?1?1) Ag peak of 3A after annealing for 20 h at 300 or 500 °C for 10 min. The improved thermal stability of the 5A electrode is ascribed to the limitation function of Al atoms on Ag diffusion into the AZO layer. The polymer solar cells based on 5A compared with ITO electrodes showed a similar efficiency.

Zhou, Lin; Chen, Xiaohong; Zhu, Feng; Sun, XinXing; Sun, Zhuo

2012-12-01

158

Rapid thermal annealed WO3-doped In2O3 films for transparent electrodes in organic photovoltaics  

NASA Astrophysics Data System (ADS)

We investigated the effect of rapid thermal annealing (RTA) on the electrical, optical, structural and surface properties of WO3-doped In2O3 (IWO) films for use in organic solar cells (OSCs). Increasing the RTA temperature led to significant decreases in resistivity and sheet resistance due to activation of the W dopants and the (2?2?2) preferred orientation of the IWO films. At the optimized RTA temperature of 500 °C, the IWO film had a sheet resistance of 21 ?/square and an optical transmittance of 89.39%, which is comparable to conventional ITO electrodes. Due to the high mobility of 46 cm2 V-1 s-1, the IWO film showed a higher optical transmittance in the near infrared wavelength region even though it had a low resistivity of 4.34 × 10-4 ? cm. Furthermore, the 500 °C annealed IWO film showed very smooth surface morphology due to its (2?2?2) preferred orientation. The performance (fill factor of 61.59%, short circuit current of 8.84 mA cm-2, open circuit voltage of 0.60 V and power conversion efficiency of 3.27%) of the OSC fabricated with the IWO electrode was nearly identical to that of the OSC with a reference ITO anode, indicating that the IWO anode is a promising high-mobility transparent electrode material to replace conventional ITO anodes for high-performance OSCs.

Kim, Jun Ho; Shin, Yong-Hee; Seong, Tae-Yeon; Na, Seok-In; Kim, Han-Ki

2012-10-01

159

Roll-to-roll production of 30-inch graphene films for transparent electrodes  

Microsoft Academic Search

The outstanding electrical, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping

Sukang Bae; Hyeongkeun Kim; Youngbin Lee; Xiangfan Xu; Jae-Sung Park; Yi Zheng; Jayakumar Balakrishnan; Tian Lei; Hye Ri Kim; Young Il Song; Young-Jin Kim; Kwang S. Kim; Barbaros Özyilmaz; Jong-Hyun Ahn; Byung Hee Hong; Sumio Iijima

2010-01-01

160

Roll-to-roll production of 30-inch graphene films for transparent electrodes  

Microsoft Academic Search

The outstanding electrical1, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping

Byung Hee Hong

2011-01-01

161

High-conductivity large-area semi-transparent electrodes for polymer photovoltaics by silk screen printing and vapour-phase deposition  

Microsoft Academic Search

Transparent electrodes based on PEDOT were prepared using a variety of techniques suitable for large area applications from 3,4-ethylenedioxythiophene (EDT) and Fe(III)-tosylate. High conductivities were obtained (?20??1) with moderate transmission in the UV-visible range 350–600nm. We subsequently demonstrate the application of PEDOT electrodes to flexible polyethyleneterphthalate plastic substrates (PET) prepared by this procedure for polymer photovoltaic devices with active areas

Bjørn Winther-Jensen; Frederik C. Krebs

2006-01-01

162

Layer-by-layer self-assembled mesoporous PEDOT-PSS and carbon black hybrid films for platinum free dye-sensitized-solar-cell counter electrodes.  

PubMed

A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode. Moreover, when carbon black was added to the PEDOT-PSS solution, highly mesoporous PEDOT-PSS and carbon black hybrid films were obtained. These films showed high cathodic activity. In this study, we investigated the change in morphology in the obtained film with increasing carbon black content, and the influence of the porosity and thickness on the performance of the cells. In this study, a Pt-free counter electrode with performance similar to that of Pt-based counter electrodes was successfully fabricated. The achieved efficiency of 4.71% was only a factor of 8% lower than that of the cell using conventional thermally deposited Pt on fluorine-doped tin oxide glass counter electrodes. PMID:21430326

Kitamura, Koji; Shiratori, Seimei

2011-03-23

163

Metal-nanowall grating transparent electrodes: achieving high optical transmittance at high incident angles with minimal diffraction.  

PubMed

A novel architecture has been employed to fabricate transparent electrodes with high conductivity and high optical transmittance at high incident angles. Soft lithography is used to fabricate polymer grating patterns onto which thin metallic films are deposited. Etching removes excess metal leaving tall walls of metal. Polymer encapsulation of the structure both protects the metal and minimizes diffraction. Transmission is dependent upon the height of the walls and encapsulation and varies from 60% to 80% for structures with heights of 1400 nm to 300 nm. In encapsulated structures, very little distortion is visible (either parallel to or perpendicular to standing walls) even at viewing angles 60° from the normal. Diffraction is at characterized through measurement of intensity for zeroth through third order diffraction spots. Encapsulation is shown to significantly reduce diffraction. Measurements are supported by optical simulations. PMID:23389219

Kuang, Ping; Park, Joong-Mok; Liu, Geyuan; Ye, Zhuo; Leung, Wai; Chaudhary, Sumit; Lynch, David; Ho, Kai-Ming; Constant, Kristen

2013-01-28

164

A low-cost bio-inspired integrated carbon counter electrode for high conversion efficiency dye-sensitized solar cells.  

PubMed

A novel bio-inspired Pt- and FTO-free integrated pure carbon counter electrode (CE) for dye-sensitized solar cells (DSSCs) has been designed and fabricated using a porous carbon sheet as a conducting substrate and ordered mesoporous carbon (OMC) as the catalytic layer. A rigid, crustose lichen-like, integrated carbon-carbon composite architecture with a catalytic layer rooted in a porous conducting substrate was formed by a process of polymer precursor spin coating, infiltration and pyrolysis. The integrated pure carbon CE shows very low series resistance (R(s)), owing to the high conductivity of the carbon sheet (sheet resistance of 488 m? ?(-1)) and low charge-transfer resistance (R(ct)), due to the large specific surface area of the OMC layer that is accessible to the redox couple. The values of R(s) and R(ct) are much lower than those of a platinized fluorine-doped thin oxide glass (Pt/FTO) electrode. Cells with this CE show high solar-to-electricity conversion efficiencies (8.11%), comparable to that of Pt/FTO based devices (8.16%). PMID:23881167

Wang, Chunlei; Meng, Fanning; Wu, Mingxing; Lin, Xiao; Wang, Tonghua; Qiu, Jieshan; Ma, Tingli

2013-07-24

165

Diffused transmission and texture-induced defect with transparent conducting oxide front electrode of amorphous silicon solar cell  

NASA Astrophysics Data System (ADS)

Highly textured transparent conducting front electrode (TFE) can enhance light trapping; however, we observed an improved performance of a solar cell by nanometer level modification of surface texture. A 40 nm thick aluminum doped zinc oxide was sputter deposited at an oblique flux on the textured fluorine doped tin oxide TFE, and a TFE double layer was used for the front electrode of solar cells. The cells fabricated on these modified TFEs exhibited an increased open circuit voltage, enhancement in short circuit current density and an increase in fill factor that reached up to 74% because of reduced series resistance of the cell. The surface texture of the TFE was modified with various angular fluxes of the zinc oxide sputter particle, which shows lower texture-induced-surface defect, higher work function. These are thought to have helped in improving the performance of the thin-film solar cells. However, at a near normal angular flux of the zinc oxide sputter particle, light trapping was observed to have reduced significantly, leading to a significant reduction in current density of the cell.

Park, Hyeongsik; Iftiquar, S. M.; Kim, Hee Won; Lee, Jaehyeong; Le, Anh Huy Tuan; Yi, Junsin

2013-11-01

166

Flexible and transparent organic film speaker by using highly conducting PEDOT\\/PSS as electrode  

Microsoft Academic Search

Flexible organic film speaker (FOFS) was fabricated with ion-assisted-reaction (IAR) treated poly(vinylidene fluoide) (PVDF) as active layer and poly(3,4-ethylenedioxythiophene)\\/poly(4-styrenesulfonate) (PEDOT\\/PSS), indium tin oxide (ITO), or copper (Cu) as electrode. The PEDOT\\/PSS materials were screen printed on the PVDF surface. The dc conductivity (?dc) of pristine PEDOT\\/PSS increases from 0.8 to ?80S\\/cm by adding various organic solvents. The sound pressure level

C. S. Lee; J. Y. Kim; D. E. Lee; J. Joo; B. G. Wagh; S. Han; Y. W. Beag; S. K. Koh

2003-01-01

167

Tuning the electrical and optical properties of graphene by ozone treatment for patterning monolithic transparent electrodes.  

PubMed

Tunable electrical and optical properties of graphene are vital to promote its use as film electrodes in a variety of devices. We developed an etching-free ozone treatment method to continuously tune the electrical resistance and optical transmittance of graphene films by simply varying the time and temperature of graphene exposure to ozone. Initially, ozone exposure dramatically decreases the electrical resistance of graphene films by p-doping, but this is followed by increases in the resistance and optical transmittance as a result of surface oxidation. The rate of resistance increase can be significantly increased by raising the treatment temperature. The ozone-oxidized graphene is not removed but is gradually transformed to graphene oxide (GO). On the basis of such effects of ozone treatment, we demonstrate a well-defined graphene pattern by using ozone photolithography, in which the ozone-treated graphene electrodes are monolithic but separated by insulating GO regions. Such a monolithic graphene pattern shows low optical contrast, a clean and more hydrophilic surface, indicating the promising use of ozone treatment to achieve high-performance graphene-based optoelectronic devices. PMID:23578259

Yuan, Jiangtan; Ma, Lai-Peng; Pei, Songfeng; Du, Jinhong; Su, Yang; Ren, Wencai; Cheng, Hui-Ming

2013-04-11

168

Optimization of transparent electrode for solar cell. Technical report, 15 September 1981-14 September 1982  

SciTech Connect

Electrically conductive, transparent films of fluorine doped tin oxide have been investigated during this contract. These films were grown by the chemical vapor deposition from tetramethyl tin (TMT) in the presence of air and a freon (bromotrifluoromethane). In order to find the optimal conditions for growing high quality films, the concentrations of the reactants were varied, and the resulting film quality was related to a figure of merit (electrical conductance/optical absorbance). This figure is independent of film thickness and increases as the quality of the film is improved. As a further test of quality the variations in the bulk conductivity were also investigated and shown to vary in the same way as the figure of merit. Film growth rates as a function of varying reactant concentrations were determined. Preliminary investigations of fluorine content by Auger spectroscopy were carried out. The surface morphology of the films was studied by scanning electron microscopy, and conditions for growing either smooth or rough films are reported.

Gordon, R.G.; Proscia, J.; Ellis, F.; Kurtz, S.

1982-01-01

169

Dye-sensitized solar cells based on hydroquinone/benzoquinone as bio-inspired redox couple with different counter electrodes.  

PubMed

In the present study, tetramethylammonium hydroquinone (HQ)/benzoquinone (BQ) were developed for use as a redox couple, with poly(3,4-ethylenedioxythiophene) (PEDOT) and multiwalled carbon nanotubes (MWNT) being proposed for use as counter electrode (CE) catalysts in dye-sensitized solar cells (DSSCs). Both metal-complex N719 and metal-free organic dye CM309 were employed to fabricate devices. For the devices sensitized by N719, when using PEDOT and MWNT CEs, power conversion efficiencies (PCE) of 5.2 and 4.9% were obtained, respectively, which were much higher than that of the device using the traditional Pt CE (4.7%) when HQ/BQ electrolyte was employed. However, with the HQ/BQ redox shuttle, the efficiency of the devices sensitized by N719 is much lower than that of the devices when the traditional I(-)/I3(-) based electrolyte and Pt CE were employed (7.9%). While for the CM309 sensitized solar cells, when the HQ/BQ redox shuttle was employed, PEDOT and MWNT performed much better than Pt, the DSSC using the PEDOT CE showed an efficiency of 6.2%, which was close to that of the DSSC using the traditional I(-)/I3(-) electrolyte and Pt CE (6.3%). PMID:23925069

Cheng, Ming; Yang, Xichuan; Chen, Cheng; Zhao, Jianghua; Zhang, Fuguo; Sun, Licheng

2013-09-28

170

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

PubMed

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

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

2012-10-04

171

A soft-template-conversion route to fabricate nanopatterned hybrid pt/carbon for potential use in counter electrodes of dye-sensitized solar cells.  

PubMed

Hybrid Pt(platinum)/carbon nanopatterns with an extremely low loading level of Pt catalysts derived from block copolymer templates as an alternative type of counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) are proposed. DSSCs employing hybrid Pt/carbon with tailored configuration as CEs exhibit higher short-circuit current and conversion efficiencies as well as stability with a lapse of time compared with conventional cells on the basis of sputtered Pt thin films, evidencing that the new class of hybrid nanostructures possess high potential for cost-effective electrodes in energy conversion devices. PMID:23926029

Jang, Yu Jin; Jang, Yoon Hee; Quan, Li Na; Kim, Ho-Cheol; Pyo, Seungmoon; Kim, Dong Ha

2013-08-08

172

Optimization of transparent and reflecting electrodes for amorphous silicon solar cells  

SciTech Connect

This report describes work to improve the performance of solar cells by improving the electrical and optical properties of their transparent conducting oxides (TCO) layers. Boron-doped zinc-oxide films were deposited by atmospheric pressure chemical vapor deposition in a laminar-flow reactor from diethyl zinc, tert-butanol, and diborane in the temperature range between 300[degrees]C and 420[degrees]C. When the deposition temperature was above 320[degrees]C, both doped and undoped films have highly oriented crystallites with their c-axes perpendicular to the substrate plane. Films deposited from 0.07% diethyl zinc and 2.4% tert-butanol have electron densities between 3.5 [times] 10[sup 20] cm[sup [minus]3] and 5.5 [times] 10[sup 20] cm[sup [minus]3], conductivities between 250 [Omega][sup [minus]1] and 2500 [Omega][sup [minus]1] and mobilities between 2.5 cm[sup 2]/V-s and 35.0 cm[sup 2]/V-s, depending on dopant concentration, film thickness, and deposition temperature. Optical measurements show that the maximum infrared reflectance of the doped films is close to 90%, compared to about 20% for undoped films. Film visible absorption and film conductivity were found to increase with film thickness. The ratio of conductivity to visible absorption coefficient for doped films was between 0.1 [Omega] and 1.1 [Omega][sup [minus]1]. The band gap of the film changes from 3.3 eV to 3.7 eV when the film is doped with 0.012% diborane.

Gordon, R.G. (Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry)

1993-04-01

173

Low-cost and high-performance CoMoS4 and NiMoS4 counter electrodes for dye-sensitized solar cells.  

PubMed

Porous chalcogels CoMoS4 and NiMoS4 made by a facile solution reaction displayed good electrocatalytic activity in the redox reaction of the I(-)/I3(-) shuttle. Dye-sensitized solar cells with these ternary compounds as counter electrodes (CEs) showed photovoltaic performance similar to the devices made with noble metal platinum CE (7.46%). PMID:24022304

Zheng, Xiaojia; Guo, Jiahao; Shi, Yantao; Xiong, Fengqiang; Zhang, Wen-Hua; Ma, Tingli; Li, Can

2013-09-24

174

Solution-Processable Transparent Conductive Hole Injection Electrode for OLED SSL  

SciTech Connect

An interconnected network of silver nanowires has been used as transparent anode in OLED devices. This layer was deposited by spin-coating and slot-die coating from an aqueous nanowire suspension. The sheet resistance of the film was 10ohms/sq with a transmission (including the glass substrate) of higher than 85%. The first phase of the project focused on the implementation of this nanowire layer with a hole-injection-layer (HIL) which has been developed at Plextronics and has been shown to provide good stability and efficiency in conventional OLED devices. We modified the HIL solution such that it coated reasonably well with suitable surface morphology so that actual devices can be manufactured. During the second phase we investigated the hole-injection and stability of hole-onlydevices. We determined that the use of the nanowire network as anode does not introduce an additional degradation mechanism since the observed device characteristics did not differ from those made with ITO anode. We then proceeded to make actual OLED devices with this nanowire / HIL stack and achieved device characteristics similar state-of-the-art OLED devices with a single junction. In order to gain traction with potential OLED manufacturers, we decided to contract Novaled to prepare large-area demonstrators for us. For these devices, we used an allevaporated stack, i.e. we did use Novaledâ??s HIL material instead of Plextronicsâ??. We successfully fabricated demonstrators with an area of 25cm2 with a double or triple junction stack. Minor stack optimizations were necessary to achieve efficacies and lifetime equivalent with ITO devices made with the same devices stack. Due to the reduced microcavity effect, the color of the emitted light is significantly more stable with respect to the viewing angle compared to ITO devices. This fact in conjunction with the promise of lower production cost due to the elimination of the ITO sputtering process and the direct patterning of the anode layer are the obvious advantages of this technology. The project has shown that this nanowire technology is a viable option to achieve OLED devices with good lifetime and efficiency and we are currently working with manufacturers to utilize this technology in a production setting.

None

2012-07-15

175

Two-Dimensional Micropatterns via Crystal Growth of Na2CO3 for Fabrication of Transparent Electrodes.  

PubMed

The simple and versatile method to generate two-dimensional micropatterns by controlling precisely crystallization of sodium carbonate (Na2CO3) was investigated. Dense clusters of dendrites of salt crystals were homogeneously formed in a large area with an aqueous solution of Na2CO3 during evaporation of water. The dimensions and morphologies of dendritic salt crystals were tuned by changing the growth conditions such as salt concentration, relative humidity, and temperature. Then, 2D micropatterns of salt crystals were directly used as a mask for the deposition of a silver (Ag) layer to fabricate transparent electrodes. After salt crystals were completely dissolved in water, the network of an electrically conductive Ag layer, whose patterns were reversely produced from salt crystals, was generated on glass substrates. In addition, salt crystals were used as a master to prepare a replica mold of poly(dimethylsiloxane) (PDMS) for utilizing the imprinting technique. By imprinting a flexible PDMS mold with Ag inks, Ag micropatterns that were perfectly identical to dendrites of salt crystals were transferred to the other substrate. PMID:24003886

Lee, Dong-Eun; Go, Seungjae; Hwang, Gyungseok; Chin, Byung Doo; Lee, Dong Hyun

2013-09-17

176

Stable aqueous dispersion of reduced graphene nanosheets via non-covalent functionalization with conducting polymers and application in transparent electrodes.  

PubMed

We developed a simple and facile method of producing a stable aqueous suspension of reduced graphene oxide (RGO) nanosheets through the chemical reduction of graphene oxide in the presence of a conducting polymer dispersant, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). This approach involves the cooperative interactions of strong ?- ? interactions between a two-dimensional graphene sheet and a rigid backbone of PEDOT and the intermolecular electrostatic repulsions between negatively charged PSS bound on the RGO sheets, which impart the colloidal stability of the resulting hybrid nanocomposite of RGO/PEDOT. Moreover, our one-step solution-based method allows preserving the intrinsic chemical and electronic properties of both components, yielding a hybrid film of RGO nanosheets of high conductivity of 2.3 k?/sq with a transmittance of 80%. By taking advantage of conducting network structure of conducting polymers which provides an additional flexibility and mechanical stability of RGO nanosheets, we demonstrate the potential application of hybrid RGO/PEDOT as highly flexible and transparent electrodes. PMID:21226499

Jo, Kiyoung; Lee, Taemin; Choi, Hyun Jung; Park, Ju Hyun; Lee, Dong Jun; Lee, Dong Wook; Kim, Byeong-Su

2011-01-12

177

Large-area transparent conductive few-layer graphene electrode in GaN-based ultra-violet light-emitting diodes  

Microsoft Academic Search

We report on the development of a large-area few-layer graphene (FLG)--based transparent conductive electrode as a current spreading layer for GaN-based ultraviolet (UV) light-emitting diodes (LEDs). Large-area FLG was deposited on Cu using the chemical vapor deposition (CVD) method and subsequently transferred to the surface of the UV LED. UV light at a peak of 372 nm was emitted through

Byung-Jae Kim; Chongmin Lee; Younghun Jung; Kwang Hyeon Baik; Michael A. Mastro; Jennifer K. Hite; Charles R. Eddy; Jihyun Kim

2011-01-01

178

Electrochemical and spectroscopic characterization of anodically formed nickel salen polymer films on glassy carbon, platinum, and optically transparent tin oxide electrodes in acetonitrile containing tetramethylammonium tetrafluoroborate  

Microsoft Academic Search

Anodically polymerized films of nickel salen formed on glassy carbon, optically transparent tin oxide, and platinum electrodes in acetonitrile containing tetramethylammonium tetrafluoroborate have been examined by means of cyclic voltammetry, thin-layer voltammetry, spectroelectrochemistry, and scanning electron microscopy. With the aid of thin-layer voltammetry, it has been confirmed that the global oxidative polymerization of nickel(II) salen involves three electrons per monomer.

Christopher E. Dahm; Dennis G. Peters; Jacques Simonet

1996-01-01

179

Controlled On-chip Stimulation of Quantal Catecholamine Release from Chromaffin Cells Using Photolysis of Caged Ca2+ on Transparent Indium-Tin-Oxide Microchip Electrodes  

PubMed Central

Photorelease of caged Ca2+ is a uniquely powerful tool to study the dynamics of Ca2+-triggered exocytosis from individual cells. Using photolithography and other microfabrication techniques, we have developed transparent microchip devices to enable photorelease of caged Ca2+ together with electrochemical detection of quantal catecholamine secretion from individual cells or cell arrays as a step towards developing high-throughput experimental devices. A 100 nm - thick transparent Indium-Tin-Oxide (ITO) film was sputter-deposited onto glass coverslips, which were then patterned into 24 cell-sized working electrodes (?20 ?m by 20 ?m). We loaded bovine chromaffin cells with acetoxymethyl (AM) ester derivatives of the Ca2+ cage NP-EGTA and Ca2+ indicator dye Fura-4F, then transferred these cells onto the working ITO electrodes for amperometric recordings. Upon flash photorelease of caged Ca2+, a uniform rise of [Ca2+]i within the target cell leads to quantal release of oxidizable catecholamines measured amperometrically by the underlying ITO electrode. We observed a burst of amperometric spikes upon rapid elevation of [Ca2+]i and a “priming” effect of sub-stimulatory [Ca2+]i on the response of cells to subsequent [Ca2+]i elevation, similar to previous reports using different techniques. We conclude that UV photolysis of caged Ca2+ is a suitable stimulation technique for higher-throughput studies of Ca2+-dependent exocytosis on transparent electrochemical microelectrode arrays.

Chen, Xiaohui; Gao, Yuanfang; Hossain, Maruf; Gangopadhyay, Shubhra; Gillis, Kevin D.

2008-01-01

180

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

181

Electrochemiluminescent microoptoprobe with mini-grid working electrode and self-contained sample container  

Microsoft Academic Search

A new electrochemiluminescence (ECL) microoptoprobe with simple structure, small sampling volume and high efficiency was developed. It was constructed by fixing the transparent gold mini-grid on the end surface of the optical fiber, and by surrounding the fiber with the counter- and reference electrodes to form a self-contained three-electrode system. The use of mini-grid electrode increased the surface area and

Haiyan Wang; Guobao Xu; Shaojun Dong

2002-01-01

182

Using modified poly(3,4-ethylene dioxythiophene): Poly(styrene sulfonate) film as a counter electrode in dye-sensitized solar cells  

Microsoft Academic Search

Dye-sensitized solar cells (DSSCs), assembling with nano-crystalline TiO2 adsorbed cis-Ru(dcb)2(NCS)2 dye (known as N3) using polar solvent-treated poly(3,4-ethylene dioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) coating on a conductive glass (fluorine-doped tin oxide, FTO) as a counter electrode, were studied. The conductivity of a bare PEDOT:PSS film was only 2±0.05S\\/cm. However, the conductivities of PEDOT:PSS films treated with dimethyl sulfoxide (DMSO), N,N-dimethyl acetamide

Jian-Ging Chen; Hung-Yu Wei; Kuo-Chuan Ho

2007-01-01

183

Enhanced performance of dye-sensitized solar cells using solution-based in situ synthesis and fabrication of Cu2ZnSnSe4 nanocrystal counter electrode.  

PubMed

On the bright side: A solution-based strategy was developed for in situ synthesis and film deposition of Cu2ZnSnSe4 nanocrystal films (samples a-d). The obtained Cu2ZnSnSe4 nanocrystal films can be used as an effective counter-electrode (CE) material to replace Pt, and yield low-cost, high-efficiency dye-sensitized solar cells (DSSCs). The assembled solar cell devices exhibit an efficiency of 7.82?% under 1?sun irradiation (see figure). PMID:23780791

Yuan, Sheng-Jie; Zhou, Zheng-Ji; Hou, Ze-Liang; Zhou, Wen-Hui; Yao, Rong-Yue; Zhao, Yang; Wu, Si-Xin

2013-06-18

184

Enhanced light output power of near UV light emitting diodes with graphene / indium tin oxide nanodot nodes for transparent and current spreading electrode.  

PubMed

We report GaN-based near ultraviolet (UV) light emitting diode (LED) that combines indium tin oxide (ITO) nanodot nodes with two-dimensional graphene film as a UV-transparent current spreading electrode (TCSE) to give rise to excellent UV emission efficiency. The light output power of 380 nm emitting UV-LEDs with graphene film on ITO nanodot nodes as TCSE was enhanced remarkably compared to conventional TCSE. The increase of the light output power is attributed to high UV transmittance of graphene, effective current spreading and injection, and texturing effect by ITO nanodots. PMID:22109191

Seo, Tae Hoon; Lee, Kang Jea; Park, Ah Hyun; Hong, Chang-Hee; Suh, Eun-Kyung; Chae, Seung Jin; Lee, Young Hee; Cuong, Tran Viet; Pham, Viet Hung; Chung, Jin Suk; Kim, Eui Jung; Jeon, Seong-Ran

2011-11-01

185

Improved photovoltaic effects in InGaN-based multiple quantum well solar cell with graphene on indium tin oxide nanodot nodes for transparent and current spreading electrode  

NASA Astrophysics Data System (ADS)

We implemented graphene network on indium tin oxide (ITO) nanodots to a transparent and current-spreading electrode in InGaN-based solar cell to improve power conversion efficiency. The external quantum efficiency and short circuit current density (Jsc) of solar cells with graphene network on ITO nanodots were enhanced compared to those of solar cells with ITO and bare graphene film. The increase of the power conversion efficiency is attributed to the high transmittance, internal light-scattering effect, and effective carrier absorption of ITO nanodots.

Hoon Seo, Tae; Shim, Jae-Phil; Jin Chae, Seung; Shin, GangU; Kyoung Kim, Bo; Lee, Dong-Seon; Hee Lee, Young; Suh, Eun-Kyung

2013-01-01

186

Large-scale fabrication of a continuous gold network for use as a transparent conductive electrode in photo-electronic devices  

NASA Astrophysics Data System (ADS)

Large-scale periodic gold network electrodes were fabricated using the developed and versatile nanosphere lithography technique. The fabrication processes, structural characterizations and network formation mechanism were described in detail. An enhanced optical transmission peak was observed from the transmission spectrum, which could be assigned to the extraordinary transmission mediated commonly by (a) localized surface plasmon resonance (LSPR) and (b) surface plasmon polaritons. The effects of film thickness, sphere diameter (periodicity) and reactive ion etching time on their optical and electrical properties were also investigated. By controlling these three independent variables, we could tune the SPR peak position and their light transmission distributions flexibly. Our large-scale continuous gold network can serve as a transparent conductive electrode, while possessing the role of a surface plasmonic resonance component can make it very attractive for potential photo-electric device applications in a range from plasmon-enhanced broadband photovoltaics to SPR-based chemo- and biosensors.

Cheng, Ke; Cui, Zhonggang; Li, Qianqian; Wang, Shujie; Du, Zuliang

2012-10-01

187

Single wall carbon nanotubes deposited on stainless steel sheet substrates as novel counter electrodes for ruthenium polypyridine based dye sensitized solar cells.  

PubMed

We report on the implementation of stainless steel foils coated with dispersed Single Wall Carbon Nanotubes as novel, low cost and highly efficient counter electrodes for dye sensitized solar cells (DSSCs). We use commercially available non purified nanotubes dispersed in water by ultrasonication and drop cast on stainless steel substrates. When implemented on a ruthenium based DSSC we obtain a high short circuit current density (J(sc)= 9.21 mA cm(-2)), a good open circuit voltage (V(oc) = 0.660 V) and a solar energy conversion efficiency of 3.92%. The above cited values are measured under a light flux of 100 mW cm(-2) generated by a solar simulator equipped with a filter AM 1.5. The obtained results are comparable to those attained using a stainless steel counter electrode sputtered with a 2 microm thick platinum film (J(sc) 10.92 mA cm(-2), V(max) = 0.66 V and eta = 4.5%, AM 1.5). PMID:20200718

Calogero, Giuseppe; Bonaccorso, Francesco; Maragò, Onofrio M; Gucciardi, Pietro G; Di Marco, Gaetano

2010-02-08

188

Laser welding of nanoparticulate TiO2 and transparent conducting oxide electrodes for highly efficient dye-sensitized solar cell.  

PubMed

Poor interfacial contact is often encountered in nanoparticulate film-based devices. The dye-sensitized solar cell (DSSC) is a representative case in which a nanoporous TiO(2) electrode needs to be prepared on the transparent conducting oxide (TCO)-coated glass substrate. In this study, we demonstrate that the inter-electrode contact resistance accounts for a considerable portion of the total resistance of a DSSC and its efficiency can be greatly enhanced by welding the interface with a laser. TiO(2) films formed on the TCO-coated glass substrate were irradiated with a pulsed ultraviolet laser beam at 355 nm; this transmits through the TCO and glass but is strongly absorbed by TiO(2). Electron microscopy analysis and impedance measurements showed that a thin continuous TiO(2) layer is formed at the interface as a result of the local melting of TiO(2) nanoparticles and this layer completely bridges the gap between the two electrodes, improving the current flow with a reduced contact resistance. We were able to improve the efficiency by 35-65% with this process. DSSCs fabricated using a homemade TiO(2) paste revealed an efficiency improvement from eta = 3.3% to 5.4%, and an increase from 8.2% to 11.2% was achieved with the TiO(2) electrodes made from a commercial paste. PMID:20671364

Kim, Jinsoo; Kim, Jonghyun; Lee, Myeongkyu

2010-07-30

189

Laser welding of nanoparticulate TiO2 and transparent conducting oxide electrodes for highly efficient dye-sensitized solar cell  

NASA Astrophysics Data System (ADS)

Poor interfacial contact is often encountered in nanoparticulate film-based devices. The dye-sensitized solar cell (DSSC) is a representative case in which a nanoporous TiO2 electrode needs to be prepared on the transparent conducting oxide (TCO)-coated glass substrate. In this study, we demonstrate that the inter-electrode contact resistance accounts for a considerable portion of the total resistance of a DSSC and its efficiency can be greatly enhanced by welding the interface with a laser. TiO2 films formed on the TCO-coated glass substrate were irradiated with a pulsed ultraviolet laser beam at 355 nm this transmits through the TCO and glass but is strongly absorbed by TiO2. Electron microscopy analysis and impedance measurements showed that a thin continuous TiO2 layer is formed at the interface as a result of the local melting of TiO2 nanoparticles and this layer completely bridges the gap between the two electrodes, improving the current flow with a reduced contact resistance. We were able to improve the efficiency by 35-65% with this process. DSSCs fabricated using a homemade TiO2 paste revealed an efficiency improvement from ? = 3.3% to 5.4%, and an increase from 8.2% to 11.2% was achieved with the TiO2 electrodes made from a commercial paste.

Kim, Jinsoo; Kim, Jonghyun; Lee, Myeongkyu

2010-08-01

190

Coincidence Proportional Counter  

DOEpatents

A coincidence proportional counter having a plurality of collecting electrodes so disposed as to measure the range or energy spectrum of an ionizing particle-emitting source such as an alpha source, is disclosed.

Manley, J.H.

1950-07-31

191

Counter-Electrode-Free Thin Cu Film Deposition Based on Ballistic Electron Injection into CuSO4 Solution from Nanosilicon Emitter  

NASA Astrophysics Data System (ADS)

It is shown that a nanocrystalline silicon (nc-Si) ballistic electron emitter acts as an active electrode in a metal--salt solution (such as CuSO4 solution). The nc-Si emitter is composed of a thin Au film (10 nm thick), anodized polycrystalline layer (1 ?m thick), and single-crystalline n+-Si substrate. In accordance with the results of an analysis by cyclic-voltammogram measurements under the standard three-electrode configuration, the electron injection effect into the solution is clearly observed at a potential within the electrochemical window where no electrolytic reactions appear. When the nc-Si emitter is driven alone in a CuSO4 solution without using any counter electrodes, a polycrystalline thin Cu film is uniformly formed on the emitting surface. This is presumably due to the preferential reduction of Cu2+ ions at the interface by injected energetic electrons. The observed deposition mode is different from both the conventional electroplating and electroless plating. This technique is an alternative low-temperature wet process that will be applicable to the deposition of various thin metal films.

Ohta, Toshiyuki; Gelloz, Bernard; Koshida, Nobuyoshi

2011-01-01

192

A tin oxide transparent electrode provides the means for rapid time-resolved pH measurements: application to photoinduced proton transfer of bacteriorhodopsin and proteorhodopsin.  

PubMed

An electrochemical cell was previously reported in which bacteriorhodopsin (BR, purple membrane) was adsorbed on the surface of a transparent SnO(2) electrode, and illumination resulted in potential or current changes (Koyama et al., Science 265:762-765, 1994; Robertson and Lukashev, Biophys. J. 68:1507-1517, 1995; Koyama et al., Photochem. Photobiol. 68:400-406, 1998). In this paper, we concluded that pH changes caused by proton transfer by the deposited BR or proteorhodopsin (PR) films lead to the flash-induced potential change in the SnO(2) electrode. Thus, the signals originate from BR and PR acting as light-driven proton pumps. This conclusion was drawn from the following observations. (1) The relation between the potential of a bare electrode and pH is linear for a wide pH range. (2) The flash-induced potential changes decrease with an increase in the buffer concentration. (3) The action spectrum of PR agrees well with the absorption spectrum. (4) The present electrode can monitor the pH change in the time range from 10 ms to several hundred milliseconds, as deduced by comparing the SnO(2) signal with the signals of pH-sensitive dyes. Using this electrode system, flash-induced proton transfer by BR was measured for a wide pH range from 2 to 10. From these data, we reconfirmed various pK(a) values reported previously, indicating that the present method can give the correct pK(a) values. This is the first report to estimate these pK(a) values directly from the proton transfer. We then applied this method to flash-induced proton transfer of PR. We observed proton uptake followed by release for the pH range from 4 to 9.5, and in other pH ranges, proton release followed by uptake was observed. PMID:19192196

Tamogami, Jun; Kikukawa, Takashi; Miyauchi, Seiji; Muneyuki, Eiro; Kamo, Naoki

2009-01-19

193

Impurity-doped ZnO Thin Films Prepared by Physical Deposition Methods Appropriate for Transparent Electrode Applications in Thin-film Solar Cells  

NASA Astrophysics Data System (ADS)

This paper describes the development of transparent conducting impurity-doped ZnO thin films that would be appropriate for applications as transparent electrodes in thin-film solar cells. Transparent conducting Al-, B- and Ga-doped ZnO (AZO, BZO and GZO) thin films were prepared in a thickness range from 500 to 2000 nm on glass substrates at 200°C using various physical deposition methods: BZO films with vacuum arc plasma evaporation, AZO and GZO films with different types of magnetron sputtering depositions (MSDs) and all films with pulsed laser deposition (PLD). The suitability and stability of the electrical properties and, in addition, the suitability of the light scattering characteristics and surface texture formation were investigated in the prepared thin films. In particular, the suitability and stability evaluation was focused on the use of AZO, BZO and GZO thin films prepared by doping each impurity at an appropriate content to attain the lowest resistivity. The higher Hall mobility obtained in impurity-doped ZnO thin films with a resistivity on the order of 10-4 ?cm was related more to the content, i.e., the obtained carrier concentration, rather than the kind of impurity doped into the films. The stability of resistivity of the BZO thin films in long-term moisture-resistance tests (in air at 85% relative humidity and 85°C) was found to be lower than that of the AZO and GZO thin films. The surface texture formation was carried out by wet-chemical etching (in a 0.1% HCl solution at 25°C) conducted either before or after being heat-treated either with rapid thermal annealing (RTA) or without RTA. The suitability of the light scattering characteristics and the surface texture formation obtainable by wet-chemical etching (for use in transparent electrode applications) was considerably dependent on the deposition method used as well as whether the wet-chemical etching was conducted with or without RTA. A significant improvement of both transmittance and haze value at wavelengths up to about 1200 nm in the near-infrared region was attained in surface-textured AZO films that were prepared by r.f. power superimposed d.c. MSD as well as etched after being heat treated with RTA at 500°C for 5 min in air. The obtained suitability and stability in impurity-doped ZnO thin films were related more to the content rather than the kind of impurity doped into the films as well as to the deposition method used.

Minami, Tadatsugu; Miyata, Toshihiro; Nomoto, Jun-ichi

2012-04-01

194

Voltammetric Membrane Chlorine Dioxide Electrode.  

National Technical Information Service (NTIS)

A voltammetric membrane electrode system has been modified and applied to the in situ measurement of chlorine dioxide. The electrode system consisted of a gold cathode, a silver/silver chloride reference electrode, and a gold counter electrode. Different ...

R. Dormond-Herrera K. H. Mancy

1980-01-01

195

Low-noise solar-blind photodetectors based on LaAlO3 single crystal with transparent indium-tin-oxide electrode as detection window.  

PubMed

The low-noise solar-blind photodetectors of indium-tin-oxide/LaAlO(3)/Ag (ITO/LAO/Ag) have been fabricated based on the properties of LAO bandgap excitation and the transparent conductance of ITO thin film. The ITO thin films are epitaxially grown on LAO wafers as the electrodes and detection windows of the photodetectors. The photodetectors have low noise and excellent electromagnetic shielding. The influence of the thickness of ITO thin films on the responsivity of the photodetectors has been studied. The photocurrent responsivity can reach 10.3 mA/W under the irradiation of 200-220 nm for a photodetector with 5 nm thick ITO film. The noise current is 1 pA order magnitude under the sunlight at midday. The experiment results suggest that ITO/LAO/Ag is one of the promising structures for the solar-blind deep-ultraviolet photodetectors. PMID:20935715

Guo, Er-Jia; Lu, Hui-Bin; He, Meng; Jin, Kui-Juan; Yang, Guo-Zhen

2010-10-10

196

Ga-doped ZnO transparent electrodes with TiO2 blocking layer/nanoparticles for dye-sensitized solar cells  

PubMed Central

Ga-doped ZnO [GZO] thin films were employed for the transparent electrodes in dye-sensitized solar cells [DSSCs]. The electrical property of the deposited GZO films was as good as that of commercially used fluorine-doped tin oxide [FTO]. In order to protect the GZO and enhance the photovoltaic properties, a TiO2 blocking layer was deposited on the GZO surface. Then, TiO2 nanoparticles were coated on the blocking layer, and dye was attached for the fabrication of DSSCs. The fabricated DSSCs with the GZO/TiO2 glasses showed an enhanced conversion efficiency of 4.02% compared to the devices with the normal GZO glasses (3.36%). Furthermore, they showed better characteristics even than those using the FTO glasses, which can be attributed to the reduced charge recombination and series resistance.

2012-01-01

197

Low-temperature processing method of preparing for transparent graphene oxide electrode film with better electrical properties.  

PubMed

Graphene oxide films were prepared by a facile ball milling process. The milling time and the amount of the acryl type polymer dispersion agent were controlled to obtain well dispersed graphene oxide solution in ethanol. Consequently, the transparent and conducting graphene oxide film which had 69% transmittance and 1.5 x 10(6) ohm/sq surface resistance was produced by bar coating the solution on a PET substrate. The electrical property of the graphene oxide film could be further improved to 2.1 x 10(5) ohm/sq by hydrazine vapor reduction. PMID:22852393

Kim, Jin Ho; Jung, Jae Mok; Kwak, Jun Young; Hong, Seung-Soo; Gal, Yeong-Soon; Lim, Kwon Taek

2012-05-01

198

Workfunction-tunable, N-doped reduced graphene transparent electrodes for high-performance polymer light-emitting diodes.  

PubMed

Graphene is a promising candidate to complement brittle and expensive transparent conducting oxides. Nevertheless, previous research efforts have paid little attention to reduced graphene, which can be of great benefit due to low-cost solution processing without substrate transfer. Here we demonstrate workfunction-tunable, highly conductive, N-doped reduced graphene film, which is obtainable from the spin-casting of graphene oxide dispersion and can be successfully employed as a transparent cathode for high-performance polymer light-emitting diodes (PLEDs) as an alternative to fluorine-doped tin oxide (FTO). The sheet resistance of N-doped reduced graphene attained 300 ?/? at 80% transmittance, one of the lowest values ever reported from the reduction of graphene oxide films. The optimal doping of quaternary nitrogen and the effective removal of oxygen functionalities via sequential hydrazine treatment and thermal reduction accomplished the low resistance. The PLEDs employing N-doped reduced graphene cathodes exhibited a maximum electroluminescence efficiency higher than those of FTO-based devices (4.0 cd/A for FTO and 7.0 cd/A for N-doped graphene at 17,000 cd/m(2)). The reduced barrier for electron injection from a workfunction-tunable, N-doped reduced graphene cathode offered this remarkable device performance. PMID:22148918

Hwang, Jin Ok; Park, Ji Sun; Choi, Dong Sung; Kim, Ju Young; Lee, Sun Hwa; Lee, Kyung Eun; Kim, Yong-Hyun; Song, Myoung Hoon; Yoo, Seunghyup; Kim, Sang Ouk

2011-12-13

199

Advantages of using Ti-mesh type electrodes for flexible dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

We used Ti meshes for both the photoanodes and counter electrodes of dye-sensitized solar cells (DSSCs) to improve the flexibility and conductivity of the electrodes. These mesh type electrodes showed good transparency and high bendability when subjected to an external force. We demonstrated the advantages of cells using such electrodes compared to traditional transparent conducting oxide based electrodes and back side illuminated DSSCs, such as low sheet resistance, elevated photo-induced current and enhanced sunlight utilization. Nanotube layers of different thicknesses were investigated to determine their effect on the photovoltaic parameters of the cell. The overall efficiency of the best cells was approximately 5.3% under standard air mass 1.5 global (AM 1.5 G) solar conditions. Furthermore, the DSSCs showed an efficiency of approximately 3.15% due to the all Ti-mesh type electrodes even after illumination from the back side.

He, Weizhen; Qiu, Jijun; Zhuge, Fuwei; Li, Xiaomin; Lee, Jae-Ho; Kim, Yang-Do; Kim, Hyung-Kook; Hwang, Yoon-Hwae

2012-06-01

200

Efficient Organic Excitonic Solar Cells with Carbon Nanotubes Replacing In2O3:Sn as the Transparent Electrode (Presentation)  

SciTech Connect

The conclusions of this report are that: (1) organic solar cells with efficiencies of up to 1.43% conversion efficiency that use no ITO and no PEDOT:PSS, are demonstrated; (2) a cell without ITO, but with PEDOT:PSS gave 2.6% conversion efficiency; (3) due to porous nature of SWCNT substrates, optimization of the active layer is essential; and (4) SWCNT electrodes bring one step closer the goal of a fully printable, organic solar cell.

van de Lagemaat, J.; Barnes, T.; Rumbles, G.; Shaheen, S.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.

2006-05-01

201

Transparent lithium-ion batteries  

PubMed Central

Transparent devices have recently attracted substantial attention. Various applications have been demonstrated, including displays, touch screens, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices, have not yet been reported. As battery electrode materials are not transparent and have to be thick enough to store energy, the traditional approach of using thin films for transparent devices is not suitable. Here we demonstrate a grid-structured electrode to solve this dilemma, which is fabricated by a microfluidics-assisted method. The feature dimension in the electrode is below the resolution limit of human eyes, and, thus, the electrode appears transparent. Moreover, by aligning multiple electrodes together, the amount of energy stored increases readily without sacrificing the transparency. This results in a battery with energy density of 10 Wh/L at a transparency of 60%. The device is also flexible, further broadening their potential applications. The transparent device configuration also allows in situ Raman study of fundamental electrochemical reactions in batteries.

Yang, Yuan; Jeong, Sangmoo; Hu, Liangbing; Wu, Hui; Lee, Seok Woo; Cui, Yi

2011-01-01

202

One-step synthesis of stoichiometric Cu2ZnSnSe4 as counter electrode for dye-sensitized solar cells.  

PubMed

Cu(2)ZnSnSe(4) (CZTSe) nanoparticles with diameters of 200-300 nm were synthesized by one-step solvothermal method without surfactants or templates. The structure, composition and morphology of CZTSe nanoparticles were characterized by XRD, XPS, Raman spectrum, EDS, FESEM and TEM. The results indicated that the nanoparticles were single phase and nearly stoichiometric composition. CZTSe nanoparticles drop-casted onto FTO substrate were used as counter electrode (CE) in dye-sensitized solar cells (DSSCs) for the first time, which exhibited Pt-like electrocatalytic activity for the reduction of I(3)(-) to I(-) in DSSCs. The J-V results demonstrated that the thickness of the film affected the photocurrent density and fill factor remarkably, which resulted from the difference of electrocatalytic sites and resistance with different thickness films. And a best efficiency of 3.85% was obtained by adjusting the film thickness. The work presents a new approach for developing low-cost, facile fabrication CZTSe nanoparticles, and demonstrates CZTSe can be explored as a low-cost alternative for expensive and scare Pt in DSSCs. PMID:22387625

Du, Yan-Fang; Fan, Jun-Qi; Zhou, Wen-Hui; Zhou, Zheng-Ji; Jiao, Jie; Wu, Si-Xin

2012-03-12

203

Electrochemical deposition of ZnO nanorods on transparent reduced graphene oxide electrodes for hybrid solar cells.  

PubMed

Monocrystalline ZnO nanorods (NRs) with high donor concentration are electrochemically deposited on highly conductive reduced graphene oxide (rGO) films on quartz. The film thickness, optical transmittance, sheet resistance, and roughness of rGO films are systematically studied. The obtained ZnO NRs on rGO films are characterized by X-ray diffraction, transmission electron microscopy, photoluminescence, and Raman spectra. As a proof-of-concept application, the obtained ZnO NRs on rGO are used to fabricate inorganic-organic hybrid solar cells with layered structure of quartz/rGO/ZnO NR/poly(3-hexylthiophene)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (P3HT/PEDOT:PSS)/Au. The observed power conversion efficiency (PCE, eta), approximately 0.31%, is higher than that reported in previous solar cells by using graphene films as electrodes. These results clearly demonstrate that rGO films with a higher conductivity have a smaller work function and show a better performance in the fabricated solar cells. PMID:20039255

Yin, Zongyou; Wu, Shixin; Zhou, Xiaozhu; Huang, Xiao; Zhang, Qichun; Boey, Freddy; Zhang, Hua

2010-01-01

204

Design and fabrication of nanometric ZnS/Ag/MoO3 transparent conductive electrode and investigating the effect of annealing process on its characteristics  

NASA Astrophysics Data System (ADS)

In this paper, a ZnS/Ag/MoO3 (ZAM) nano-multilayer structure is designed theoretically and optimum thicknesses of each layer are calculated. ZnS/Ag/MoO3 multilayer films with optimized thicknesses have also been fabricated on glass substrates by thermal evaporation method at room temperature. The structural, electrical and optical properties of ZnS/Ag/MoO3 multilayer are investigated with respect to the variation of annealing temperature. X-ray diffraction patterns show that increase in annealing temperature increases the crystallinity of the structures. High-quality multilayer films with the sheet resistance of 4.5 ?/sq and the maximum optical transmittance of 85% at 100 °C annealing temperature are obtained. The allowed direct band gap for annealing at different temperatures is estimated to be in the range of 3.37-3.79 eV. The performance of the ZAM multilayer films are evaluated using a predefined figure of merit. These multilayer films can be used as transparent conductive electrodes in optoelectronic devices such as solar cells and organic light emitting diodes.

Kermani, Hamideh; Fallah, Hamid Reza; Hajimahmoodzadeh, Morteza

2013-01-01

205

Effect of deposition temperature on the properties of Al-doped ZnO films prepared by pulsed DC magnetron sputtering for transparent electrodes in thin-film solar cells  

NASA Astrophysics Data System (ADS)

A simple but scalable approach to the production of surface-textured Al-doped ZnO(AZO) films for low-cost transparent electrode applications in thin-film solar cells is introduced in this study by combining pulsed dc magnetron sputtering (PDMS) with wet etching in sequence. First, structural, electrical, and optical properties of the AZO films prepared by a PDMS were investigated as functions of deposition temperature to obtain transparent electrode films that can be used as indium-free alternative to ITO electrodes. Increase in the deposition temperature to 230 °C accompanied the improvement in crystalline quality and doping efficiency, which enabled the lowest electrical resistivity of 4.16 × 10-4 ? cm with the carrier concentration of 1.65 × 1021 cm-3 and Hall mobility of 11.3 cm2/V s. The wet etching of the films in a diluted HCl solution resulted in surface roughening via the formation of crater-like structures without significant degradation in the electrical properties, which is responsible for the enhanced light scattering capability required for anti-reflective electrodes in thin film solar cells.

Kim, Doo-Soo; Park, Ji-Hyeon; Shin, Beom-Ki; Moon, Kyeong-Ju; Son, Myoungwoo; Ham, Moon-Ho; Lee, Woong; Myoung, Jae-Min

2012-10-01

206

Counting Counters  

NSDL National Science Digital Library

This problem gives children an opportunity to explore an increasing pattern and then generalize the results with a rule. Students begin with a single counter, surround it by a ring of other counters and then each new ring is surrounded with more counters. Solvers record results as they replicate the pattern and make predictions about many counters there will be in any given ring. The Teachers' Notes page offers suggestions for implementation, key discussion questions, ideas for extension and support.

2003-03-01

207

NEUTRON COUNTER  

DOEpatents

An ionization chamber instrument is described for cylindrical electrodes with an ionizing gag filling the channber. The inner electrode is held in place by a hermetic insulating seal at one end of the outer electrode, the other end of the outer electrode being closed by a gas filling tube. The outer surface of the inner electrode is coated with an active material which is responsive to neutron bombardment, such as uranium235 or boron-10, to produce ionizing radiations in the gas. The transverse cross sectional area of the inner electrode is small in relation to that of the channber whereby substantially all of the radiations are directed toward the outer electrode.

Curtis, C.D.; Carlson, R.L.; Tubinis, M.P.

1958-07-29

208

Dye-sensitized solar cell based on optically transparent TiO 2 nanocrystalline electrode prepared by atomized spray pyrolysis technique  

Microsoft Academic Search

Preparation of crack-free thin films of interconnected and non-agglomerated TiO2 nanoparticles on electronically conducting fluorine doped tin oxide surfaces is instrumental in designing and developing transparent dye-sensitized solar cells (DSCs). A novel technique called “Atomized Spray Pyrolysis” (ASP) has been designed and developed to achieve such perfectly transparent thin films. Optical transmittance of TiO2 films produced on FTO surface by

H. M. N. Bandara; R. M. G. Rajapakse; K. Murakami; G. R. R. A. Kumara; G. Anuradha Sepalage

2011-01-01

209

Monitoring of morphology and physical properties of cultured cells using a micro camera and a quartz crystal with transparent indium tin oxide electrodes after injections of glutaraldehyde and trypsin.  

PubMed

For investigating the effects of chemical stimulation to cultured cells, we have developed a quartz crystal sensor system with a micro charge-coupled device (CCD) camera that enables microphotograph imaging simultaneously with quartz crystal measurement. Human hepatoma cell line (HepG2) cells were cultured on the quartz crystal through a collagen film. The electrode of the quartz crystal was made of indium tin oxide (ITO) transparent electrodes that enable to obtain a transparent mode photograph. Glutaraldehyde and trypsin were injected to the chamber of the cells, respectively. The response of the quartz crystal was monitored and microphotographs were recorded, and the resonance frequency and resonance resistance were analyzed with an F-R diagram that plotted the resonance frequency and resonance resistance. In the case of the glutaraldehyde injection, the cells responded in two steps that included the fast response of the cross-linking reaction and the successive internal change in the cells. In the case of the trypsin injection, the responses included two processes. In the first step, cell adhesion factors were cleaved and the cell structure became round, and in the next step, the cells were deposited on the quartz crystal surface and the surface of the cells was directly in contact with the quartz crystal surface. PMID:18706321

Kang, Hyen-Wook; Ida, Kazumi; Yamamoto, Yuji; Muramatsu, Hiroshi

2008-07-01

210

Optimization of transparent and reflecting electrodes for amorphous-silicon solar cells. Final subcontract report, 1 May 1991--30 April 1994  

SciTech Connect

Fluorine-doped zinc oxide was shown to have the lowest absorption loss of any of the known transparent conductors. An apparatus was constructed to deposit textured, transparent, conductive, fluorine-doped zinc oxide layers with uniform thickness over a 10 cm by 10 cm area, using inexpensive, high-productivity atmospheric pressure chemical vapor deposition. Amorphous silicon solar cells grown on these textured films show very high peak quantum efficiencies (over 90%). However, a significant contact resistance develops at the interface between the amorphous silicon and the zinc oxide. Transparent, conductive gallium-doped zinc oxide films were grown by APCVD at a low enough temperature (260{degree}C) to be deposited on amorphous silicon as a final conductive back contact to solar cells. A quantum-mechanical theory of bonding was developed and applied to some metal oxides; it forms a basis for understanding TCO structures and the stability of their interfaces with silicon.

Gordon, R.G.; Hu, J.; Lacks, D.; Musher, J.; Thornton, J.; Liang, H. [Harvard Univ., Cambridge, MA (United States)

1994-07-01

211

A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles.  

PubMed

Application of two-dimensional surface electrode arrays can provide a means of mapping motor unit action potentials on the skin surface above a muscle. The resulting muscle tissue displacement can be quantified, in a single plane, using ultrasound (US) imaging. Currently, however, it is not possible to simultaneously map spatio-temporal propagation of activation and resulting tissue strain. In this paper, we developed and tested a material that will enable concurrent measurement of two-dimensional surface electromyograms (EMGs) with US images. Specific protocols were designed to test the compatibility of this new electrode material, both with EMG recording and with US analysis. Key results indicate that, for this new electrode material, 1) the electrode-skin impedance is similar to that of arrays of electrodes reported in literature; 2) the reflection of US at the electrode-skin interface is negligible; 3) the likelihood of observing missing contacts, short-circuits, and artifacts in EMGs is not affected by the US probe; 4) movement of tissues sampled by US can be tracked accurately. We, therefore, conclude this approach will facilitate multimodal imaging of muscle to provide new spatio-temporal information regarding electromechanical function of muscle. This is relevant to basic physiology-biomechanics of active and passive force transmission through and between muscles, of motor unit spatio-temporal activity patterns, of their variation with architecture and task-related function, and of their adaptation with aging, training-exercise-disuse, neurological disease, and injury. PMID:23908313

Botter, A; Vieira, T M M; Loram, I D; Merletti, R; Hodson-Tole, E F

2013-08-01

212

VOLTAMMETRIC MEMBRANE CHLORINE DIOXIDE ELECTRODE  

EPA Science Inventory

A voltammetric membrane electrode system has been modified and applied to the in situ measurement of chlorine dioxide. The electrode system consisted of a gold cathode, a silver/silver chloride reference electrode, and a gold counter electrode. Different membrane materials were t...

213

Stochastic transparency.  

PubMed

Stochastic transparency provides a unified approach to order-independent transparency, antialiasing, and deep shadow maps. It augments screen-door transparency using a random sub-pixel stipple pattern, where each fragment of transparent geometry covers a random subset of pixel samples of size proportional to alpha. This results in correct alpha-blended colors on average, in a single render pass with fixed memory size and no sorting, but introduces noise. We reduce this noise by an alpha correction pass, and by an accumulation pass that uses a stochastic shadow map from the camera. At the pixel level, the algorithm does not branch and contains no read-modify-write loops, other than traditional z-buffer blend operations. This makes it an excellent match for modern massively parallel GPU hardware. Stochastic transparency is very simple to implement and supports all types of transparent geometry, able without coding for special cases to mix hair, smoke, foliage, windows, and transparent cloth in a single scene. PMID:20921587

Enderton, Eric; Sintorn, Erik; Shirley, Peter; Luebke, David

2011-08-01

214

Welcoming transparency.  

PubMed

In this column, the editor of The Journal of Perinatal Education (JPE) discusses why there is a need for transparency to improve maternity care. The editor also describes the contents of this JPE issue, which offer a broad range of resources, research, and inspiration for childbirth educators in their efforts to promote normal birth. PMID:19516885

Budin, Wendy C

2009-01-01

215

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

PubMed

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

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

2012-12-07

216

General strategy for fabricating transparent TiO2 nanotube arrays for dye-sensitized photoelectrodes: illumination geometry and transport properties.  

PubMed

We report on the preparation of transparent oriented titania nanotube (NT) photoelectrodes and the effect of illumination direction on light harvesting, electron transport, and recombination in dye-sensitized solar cells (DSSCs) incorporating these electrodes. High solar conversion efficiency requires that the incident light enters the cell from the photoelectrode side. However, it has been synthetically challenging to prepare transparent TiO(2) NT electrodes by directly anodizing Ti metal films on transparent conducting oxide (TCO) substrates because of the difficulties of controlling the synthetic conditions. We describe a general synthetic strategy for fabricating transparent TiO(2) NT films on TCO substrates. With the aid of a conducting Nb-doped TiO(2) (NTO) layer between the Ti film and TCO substrate, the Ti film was anodized completely without degrading the TCO. The NTO layer was found to protect the TCO from degradation through a self-terminating mechanism by arresting the electric field-assisted dissolution process at the NT-NTO interface. The illumination direction and wavelength of the light incident on the DSSCs were shown to strongly influence the incident photon-to-current conversion efficiency, light-harvesting, and charge-collection properties, which, in turn, affect the photocurrent density, photovoltage, and solar energy conversion efficiency. Effects of NT film thickness on the properties and performance of DSSCs were also examined. Illuminating the cell from the photoelectrode substantially increased the conversion efficiency compared with illuminating it from the counter-electrode side. PMID:21395234

Kim, Jin Young; Noh, Jun Hong; Zhu, Kai; Halverson, Adam F; Neale, Nathan R; Park, Sangbaek; Hong, Kug Sun; Frank, Arthur J

2011-03-11

217

Effect of surface nanomorphology and interfacial galvanic coupling of PEDOT-titanium counter electrodes on the stability of dye-sensitized solar cell.  

PubMed

The present study demonstrates a novel approach by which titanium foils coated with electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) in combination with sputtered platinum can be processed into a high-surface area cathodes for dye-sensitized solar cells (DSSCs). A detailed study has been performed to elucidate how surface nanomorphology and I(-)/I(3-) redox reaction behaviors underlying these photocathodes impact the DSSC performances. From the analysis of the relevant electrochemical parameters, an intrinsic correlation between the photovoltaic performances and the cathode surface area has been deduced for such a system and explained on the basis of relative contributions of the galvanic coupling properties of the nanomorphology PEDOT film and platinum. Depending on the type of photocathodes incorporated, it was observed that these PEDOT coated cathodes can exhibit higher stability over a given time range and photo-conversion efficiencies 12-40%, higher than that achievable in absence of the intermediate PEDOT coatings. It has been shown that DSSCs based on such metal-polymer hybrid photo-cathodes allow significant room for improvement in the catalytic performance at the electrode/electrolyte interface. PMID:22962746

Madhavan, Asha Anish; Kalluri, Sujith; Paravannoor, Anjali; Nagarajan, Sivakumar; Subramanian, Kavasseri R V; Nair, Shantikumar; Balakrishnan, Avinash

2012-08-01

218

Spray deposition of water-soluble multiwall carbon nanotube and Cu2ZnSnSe4 nanoparticle composites as highly efficient counter electrodes in a quantum dot-sensitized solar cell system.  

PubMed

In this paper, low-cost counter electrodes (CEs) based on water-soluble multiwall carbon nanotube (MWCNT) and Cu2ZnSnSe4 nanoparticle (CZTSe NP) composites have been successfully introduced into a quantum dot-sensitized solar cell (QDSC) system. Suitable surface modification allows the MWCNTs and CZTSe NPs to be homogeneously dispersed in water, facilitating the subsequent low-temperature spray deposition of high quality composite films with different composite ratios. The electrochemical catalytic activity of the composite CEs has been critically compared by electrochemical impedance spectroscopy and Tafel-polarization analysis. It is found that the composite CE at the MWCNT : CZTSe ratio of 0.1 offers the best performance, leading to an optimal solar cell efficiency of 4.60%, which is 50.8% higher than that of the Pt reference CE. The as-demonstrated higher catalytic activity of the composite CEs compared to their single components could be ascribed to the combination of the fast electron transport of the MWCNTs and the high catalytic activity of CZTSe NPs. PMID:23800939

Zeng, Xianwei; Xiong, Dehua; Zhang, Wenjun; Ming, Liqun; Xu, Zhen; Huang, Zhanfeng; Wang, Mingkui; Chen, Wei; Cheng, Yi-Bing

2013-08-01

219

Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual subcontract report, 1 May 1991--30 April 1992  

SciTech Connect

This report describes work to improve the performance of solar cells by improving the electrical and optical properties of their transparent conducting oxides (TCO) layers. Boron-doped zinc-oxide films were deposited by atmospheric pressure chemical vapor deposition in a laminar-flow reactor from diethyl zinc, tert-butanol, and diborane in the temperature range between 300{degrees}C and 420{degrees}C. When the deposition temperature was above 320{degrees}C, both doped and undoped films have highly oriented crystallites with their c-axes perpendicular to the substrate plane. Films deposited from 0.07% diethyl zinc and 2.4% tert-butanol have electron densities between 3.5 {times} 10{sup 20} cm{sup {minus}3} and 5.5 {times} 10{sup 20} cm{sup {minus}3}, conductivities between 250 {Omega}{sup {minus}1} and 2500 {Omega}{sup {minus}1} and mobilities between 2.5 cm{sup 2}/V-s and 35.0 cm{sup 2}/V-s, depending on dopant concentration, film thickness, and deposition temperature. Optical measurements show that the maximum infrared reflectance of the doped films is close to 90%, compared to about 20% for undoped films. Film visible absorption and film conductivity were found to increase with film thickness. The ratio of conductivity to visible absorption coefficient for doped films was between 0.1 {Omega} and 1.1 {Omega}{sup {minus}1}. The band gap of the film changes from 3.3 eV to 3.7 eV when the film is doped with 0.012% diborane.

Gordon, R.G. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry

1993-04-01

220

Transparency triumphs.  

PubMed

The Texas Medical Association helped a group of Weslaco physicians win a preliminary victory for financial transparency at nonprofit hospitals in their ongoing legal battle with a local hospital. Twenty-six physicians, who created the Trust of Weslaco, alleged financial improprieties at Knapp Medical Center and reported quality-of-care concerns such as inadequate coverage by specialists, an insufficient number of nurses and support staff, and a high turnover of nurses and support staff. Judge Israel Ramon Jr. ordered the medical center to release balance sheets; cash flow statements; management letters from the external auditor; compensation documentation for all employees; documentation of deferred executive compensation; and other financial records. PMID:22714828

Conde, Crystal

2012-03-01

221

Electrowetting on flexible, transparent and conducting single-layer graphene  

Microsoft Academic Search

This paper reports the results of using graphene as a novel electrode material in the experiment of electrowetting on dielectric (EWOD). The device has a Teflon layer coated CVD graphene electrode which is patterned on transparent and flexible substrates such as PET films. By applying a potential difference between a liquid droplet and a graphene electrode, we observed a change

X. B. Tan; J. Yang; P. Zeng; E. G. R. Kim; C. Huard; M. M. C. Cheng

2012-01-01

222

Optical and Electrical Properties of Conducting Electrodes  

Microsoft Academic Search

Recent advances in infrared device technology require transparent conducting electrodes (TCE's) for a variety of applications. In addition to being transparent in the infrared, these electrodes need to have good dc conductivity on the order of 100 Omega\\/square. The presence of a strong plasma edge in the near IR makes Indium-Tin Oxide, the standard TCE for the visible, not suitable

Nacira Tache; Olga Drozdova; Maria Nikolou; David B. Tanner; Partha Mitra; Arthur F. Hebard; Gregory J. Exarhos; Charles F. Windisch Jr.; Robert R. Owings; Paul H. Holloway

2003-01-01

223

Composite Films Based on Poly(3,4-ethylene dioxythiophene):Poly(styrene sulfonate) Conducting Polymer and TiC Nanoparticles as the Counter Electrodes for Flexible Dye-Sensitized Solar Cells  

NASA Astrophysics Data System (ADS)

A composite film of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and titanium carbide nanoparticles (TiC-NPs) was deposited on an indium doped tin oxide--poly(ethylene naphthalate) (ITO--PEN) conducting plastic substrate by a doctor blade technique. This ITO--PEN substrate with the composite film was used as the flexible counter electrode (CE) for a plastic dye-sensitized solar cell (DSSC). Performances of the plastic DSSC with the platinum-free CEs containing PEDOT:PSS/TiC-NPs composite was investigated. A solar-to-electricity conversion efficiency (?) of 6.50% was achieved for the pertinent DSSC with PEDOT:PSS/TiC-NPs composite, using commercial N719 dye, which exhibited comparable performance to that of a cell with a sputtered-Pt film on its CE (6.84%). The homogeneous nature of the composite film PEDOT:PSS/TiC-NPs, the uniform distribution of TiC-NPs in its PEDOT:PSS matrix, and the large electrochemical surface area of the composite film are seen to be the factors for the best performance of the pertinent DSSC. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize the TiC-NPs. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy dispersive X-ray spectroscopy (EDX) were used to characterize the films. The high efficiency of the cell with PEDOT:PSS/TiC-NPs is explained by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and incident photon-to-current conversion efficiency (IPCE) curves.

Yeh, Min-Hsin; Lin, Lu-Yin; Li, Yu-Yan; Chang, Jeffrey; Chen, Ping-Wei; Lee, Chuan-Pei; Ho, Kuo-Chuan

2012-10-01

224

Facile Synthesis of Poly(3,4-ethylenedioxythiophene) Film via Solid-State Polymerization as High-Performance Pt-Free Counter Electrodes for Plastic Dye-Sensitized Solar Cells.  

PubMed

A high-performance Pt-free counter electrode (CE) based on poly(3,4-ethylenedioxythiophene) (PEDOT) film for plastic dye-sensitized solar cells (DSCs) has been developed via a facile solid-state polymerization (SSP) approach. The polymerization was simply initiated by sintering the monomer, 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT), at the temperature of 80 °C, which can be applied on the plastic substrate. The cyclic voltammetry measurements revealed that the catalytic activity of the SSP-PEDOT CE for triiodide reduction is comparable with that of the Pt CE. Under optimized conditions, the power conversion efficiency of a DSC with a N719-sensitized TiO2 photoanode and the SSP-PEDOT CE is 7.04% measured under standard 1 sun illumination (100 mW cm(-2), AM 1.5), which is very close to that of the device fabricated under the same conditions with a conventional thermally deposited Pt CE (7.35%). Furthermore, taking advantage of the compatibility of the SSP-PEDOT with the plastic substrates, a full plastic N719-sensitized TiO2 solar cell was demonstrated, and an efficiency of 4.65% was achieved, which is comparable with the performance of a plastic DSC with a sputter-deposited Pt CE (5.38%). These results demonstrated that solid-state polymerization initiated at low temperature is a facile and low-cost method of fabricating the high-performance Pt-free CEs for plastic DSCs. PMID:23927540

Yin, Xiong; Wu, Fan; Fu, Nianqing; Han, Jing; Chen, Dongliang; Xu, Peng; He, Meng; Lin, Yuan

2013-08-22

225

Optimization of Nb{sub 2}O{sub 5}/Ag/Nb{sub 2}O{sub 5} multilayers as transparent composite electrode on flexible substrate with high figure of merit  

SciTech Connect

Different multilayer structures of Nb{sub 2}O{sub 5}/Ag/Nb{sub 2}O{sub 5} have been deposited onto flexible substrates by sputtering at room temperature to develop an indium free transparent composite electrode. The effect of Ag thickness on the electrical and optical properties of the multilayer stack has been studied in accordance with the Ag morphology. The critical thickness of Ag to form a continuous conducting layer is found to be 9.5 nm. A new conduction mechanism has been proposed to describe the conduction before and after the critical thickness. The effective Hall resistivity of the optimized films is as low as 6.44 Multiplication-Sign 10{sup -5} Ohm-Sign -cm with a carrier concentration and mobility of 7.4 Multiplication-Sign 10{sup 21} cm{sup -3} and 13.1 cm{sup 2} /V-s, respectively, at the critical Ag layer thickness. The multilayer stack has been optimized to obtain a sheet resistance of 7.2 Ohm-Sign /sq and an average optical transmittance of 86% at 550 nm without any substrate heating or post-annealing process. The Haacke figure of merit (FOM) has been calculated for the films, and the multilayer with a 9.5 nm thick Ag layer has the highest FOM at 31.5 Multiplication-Sign 10-3 {Omega}{sup -1}, which is one of the highest FOM values reported for TCE deposited at room temperature on a flexible substrate.

Dhar, Aritra [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287 (United States); Alford, T. L. [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States)

2012-11-15

226

Flowchart schemata with counters  

Microsoft Academic Search

The translation of a specific flowchart schema with one counter into an equivalent flowchart schema without counters is described. This result leads easily to the general translation method from one-counter flowchart schemata to zero-counter flowchart schemata. Some generalizations are then presented.

David A. Plaisted

1972-01-01

227

Central Bank Transparency  

Microsoft Academic Search

Central bank transparency has become one of the key features of monetary policy recently. This survey article provides a structured review of the theoretical literature on the consequences of transparency of monetary policy, proposing a distinction between uncertainty and incentive effects of transparency. The theoretical insights are compared to the various ways in which central banks have become transparent in

Petra M. Geraats

2002-01-01

228

Use of silica aerogels in Cherenkov counters  

Microsoft Academic Search

Silica aerogel is widely used as a radiator for Cherenkov detectors. It is a highly porous, low-density, and transparent substance\\u000a with refractive index n ranging between the values of n n ? 1.3 for condensed phases. The review is devoted to the consideration of various factors affecting the identification of\\u000a particles in Cherenkov counters: the chromatic aberration, the number of

Yu. N. Kharzheev

2008-01-01

229

Fabrication of tantalum and nitrogen codoped ZnO (Ta, N-ZnO) thin films using the electrospay: twin applications as an excellent transparent electrode and a field emitter.  

PubMed

The realization of stable p-type nitrogen-doped ZnO thin films with durable and controlled growth is important for the fabrication of nanoscale electronic and optoelectronic devices. ZnO thin films codoped with tantalum and nitrogen (Ta, N-ZnO) were fabricated by using the electrospraying method at an atmospheric pressure. X-ray diffraction (XRD) studies demonstrated that all the prepared films were polycrystalline in nature with hexagonal wurtzite structure. In addition, a shift in the XRD patterns was observed, and the crystal orientation was changed at a certain amount of nitrogen (>6 at.%) in the starting solution. Analysis of X-ray diffraction patterns and X-ray photoelectron spectra revealed that nitrogen which was combined with the zinc atom (N-Zn) was successfully doped into the ZnO crystal lattice. It was also observed that 2 at.% tantalum and 6 at.% nitrogen (2 at.% Ta and 6 at.% N) were the optimal dopant amounts to achieve the minimum resistivity of about 9.70 × 10(-5) ? cm and the maximum transmittance of 98% in the visible region. Consequently, the field-emission characteristics of such a Ta, N-ZnO emitter can exhibit the higher current density of 1.33 mA cm(-2), larger field-enhancement factor (?) of 4706, lower turn-on field of 2.6 V ?m(-1), and lower threshold field of 3.5 V ?m(-1) attributed to the enhanced conductivity and better crystallinity of films. Moreover, the obtained values of resistivity were closest to the lowest resistivity values among the doped ZnO films as well as to the indium tin oxide (ITO) resistivity values that were previously studied. We confirmed that the tantalum and nitrogen atoms substitution in the ZnO lattice induced positive effects in terms of enhancing the free carrier concentration which will further improve the electrical, optical, and field-emission properties. The proposed electrospraying method was well suitable for the fabrication of Ta, N-ZnO thin films at optimum conditions with superior electrical, optical, and field-emission characteristics, implying the potential applications as both a transparent electrode and field-emission (FE) devices. PMID:23547983

Mahmood, Khalid; Park, Seung Bin; Sung, Hyung Jin

2013-04-16

230

Vehicle Classifying Counter.  

National Technical Information Service (NTIS)

The report concerns the design, development and testing of a vehicle classifying counter. The vehicle classifying counter was developed at the Materials and Research Department to classify vehicles by their wheelbase and number of axles. Tests were perfor...

E. F. Nordlin L. G. Kubel A. F. Bailey T. F. Grillo L. E. Welsh

1969-01-01

231

Visibly transparent polymer solar cells produced by solution processing.  

PubMed

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

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

2012-07-12

232

Transparent Conductive Oxides for Organic Electronics  

NASA Astrophysics Data System (ADS)

Organic solar cells and organic light emitting diodes are on the forefront of emerging technologies aimed at harnessing light in ways never thought possible. Large-area installations of OLED solid state lighting (SSL), as well as organic photovoltaics (OPVs), will become possible as the efficiencies of these devices continue to rise. All organic solar cells and OLEDs require the use of transparent conductive electrodes. Indium oxide (ITO) is currently the transparent conductor of choice for these applications, due to its unique combination of transparency, high conductivity, durability, and favourable surface properties. Indium, however, is a rare and expensive metal; proposed large-area installations of OPV cells and OLEDs will add further strain to global indium supply. Transparent conductive materials that are abundant, inexpensive, and which enable efficient and robust organic devices must therefore be developed. In the present work, suitable ITO anode replacement materials are demonstrated for OLEDs, small-molecule, polymer, and PbS colloidal quantum dot photovoltaics.

Murdoch, Graham Blair

233

Transparency Durability Test Criteria.  

National Technical Information Service (NTIS)

The focus of the Transparency Durability Test Criteria Program was to develop a durability test methodology for aircraft transparency systems which includes laboratory coupon durability testing and field service data acquisition. These areas were used to ...

T. J. Whitney D. R. Bowman

1996-01-01

234

Electromagnetically Induced Transparency.  

National Technical Information Service (NTIS)

We report the first observation of electromagnetically induced transparency in optically thick medium. The transparency results from a destructive interference of two dressed states which are created by applying a temporally smooth coupling laser between ...

A. Imamoglu K. J. Boiler S. E. Harris

1992-01-01

235

Transparent, flexible supercapacitors from nano-engineered carbon films.  

PubMed

Here we construct mechanically flexible and optically transparent thin film solid state supercapacitors by assembling nano-engineered carbon electrodes, prepared in porous templates, with morphology of interconnected arrays of complex shapes and porosity. The highly textured graphitic films act as electrode and current collector and integrated with solid polymer electrolyte, function as thin film supercapacitors. The nanostructured electrode morphology and the conformal electrolyte packaging provide enough energy and power density for the devices in addition to excellent mechanical flexibility and optical transparency, making it a unique design in various power delivery applications. PMID:23105970

Jung, Hyun Young; Karimi, Majid B; Hahm, Myung Gwan; Ajayan, Pulickel M; Jung, Yung Joon

2012-10-26

236

Transparent, flexible supercapacitors from nano-engineered carbon films  

NASA Astrophysics Data System (ADS)

Here we construct mechanically flexible and optically transparent thin film solid state supercapacitors by assembling nano-engineered carbon electrodes, prepared in porous templates, with morphology of interconnected arrays of complex shapes and porosity. The highly textured graphitic films act as electrode and current collector and integrated with solid polymer electrolyte, function as thin film supercapacitors. The nanostructured electrode morphology and the conformal electrolyte packaging provide enough energy and power density for the devices in addition to excellent mechanical flexibility and optical transparency, making it a unique design in various power delivery applications.

Jung, Hyun Young; Karimi, Majid B.; Hahm, Myung Gwan; Ajayan, Pulickel M.; Jung, Yung Joon

2012-10-01

237

Transparency in monetary policy  

Microsoft Academic Search

The paper examines different aspects of transparency. Transparency serves democratic accountability by promoting public control.\\u000a Specifically, the degree of transparency conditions inflation expectations, hence the central bank's scope for stabilization.\\u000a Recent studies have put doubt on the notion that complete transparency is socially desirable. Here it is pointed out that\\u000a the conclusion critically depends on an asymmetric modelling of stochastic

Manfred J. M. Neumann

2002-01-01

238

Soils. Transparency Masters.  

ERIC Educational Resources Information Center

This document is a collection of 43 overhead transparency masters to be used as teaching aids in a course of study involving soils such as geology, agronomy, hydrology, earth science, or land use study. Some transparencies are in color. Selected titles of transparencies may give the reader a better understanding of the graphic content. Titles are:…

Clemson Univ., SC. Vocational Education Media Center.

239

The art of transparency.  

PubMed

Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles. PMID:23145252

Sayim, Bilge; Cavanagh, Patrick

2011-10-27

240

A transparent ?ECoG array for simultaneous recording and optogenetic stimulation  

Microsoft Academic Search

In this paper we report for the first time the design, fabrication and characterization of an optically transparent electrode array for micro-electrocorticography. We present a 49-channel ?ECoG array with an electrode pitch of 800 ?m and a 16-channel linear ?ECoG array with an electrode pitch of 200 ?m. The backing material was Parylene C. Transparent, sputtered indium tin oxide (ITO)

Peter Ledochowitsch; Elisa Olivero; Tim Blanche; Michel M. Maharbiz

2011-01-01

241

TickCounter  

NSDL National Science Digital Library

Would you like to countdown? Or count up? Well then TickCounter might be worth checking out. TickCounter lets users create their own countdown clock so that they can keep tabs on important events and dates. Visitors can customize the clock for the time zone of their choice, and they can also give each event or date a name for easy reference. TickCounter is compatible with all operating systems.

2011-01-01

242

A Toroidal Geiger Counter  

Microsoft Academic Search

A TOROIDAL Geiger counter has been constructed in an attempt to produce a gamma-ray sensitivity detector with a response independent of the position of the gamma-ray source over a small region of space. The counter was made from two U-shaped half-sections (radius ½ in.), one of which is shown in the photograph, pressed from 24 S.W.G. oxygen-free copper. The counter

C. P. Haigh

1951-01-01

243

Transparency and Ambiguity in Central Bank Safety Net Operations  

Microsoft Academic Search

To mitigate the risks of contagion from problems arising in the banking sector, many countries operate some form of banking sector safety net. Such safety nets generally involve a judicious mixture of transparency and ambiguity. This ambiguity may be important to counter moral hazard effects but may lead to excessive forbearance in the face of banking problems. While the scope

Charles Enoch; Peter Stella; May Khamis

1997-01-01

244

An Inexpensive Radiation Counter.  

ERIC Educational Resources Information Center

|Describes a radiation counter comparable to commercial units which costs less than $100. It consists of six sections: Geiger-Mueller tube and holder; high voltage supply; low voltage supply; pulse shaping circuit; "start/stop counts" gating circuit; and counter/display. List of materials needed and schematic diagrams are included. (JN)|

Holton, Brian; Balla, Zsolt

1985-01-01

245

Pyrochemical multiplicity counter development  

SciTech Connect

Impure plutonium-bearing materials from pyrochemical processes often display both significant self-multiplication and variable ({alpha},n) reaction rates. Standard neutron coincidence counting techniques usually fail to accurately measure these materials. Neutron multiplicity counters measure the third moment of the neutron multiplicity distribution and thus make it possible to deduce the fertile plutonium mass of a sample even when both the self-multiplication and the ({alpha},n) reaction rate are unknown. A multiplicity counter suitable for measuring pyrochemical materials has been designed and built. This paper describes the results of characterization studies for the new counter. The counter consists of 126 helium-3 tubes arranged in 4 concentric rings in a polyethylene moderator; the average spacing between the tubes is 1.59 cm. The end plugs for the counter are made of graphite, and the 24.1- by 37.5-cm sample cavity is cadmium lined. The counter consists of two distinct halves from which the neutron counts are summed. The counter is capable of operation in either a freestanding mode with the two halves coupled together by an external cabinet or in a glove-box mode with the two halves placed around a glovebox well and then mated. For a {sup 252}Cf source centered in the sample cavity, the measured efficiency of the new multiplicity counter is 57.7% and its die-away time is 47.2{mu}s. 8 refs., 9 figs.

Langner, D.G.; Dytlewski, N.; Krick, M.S.

1991-01-01

246

Conditions for perceptual transparency  

NASA Astrophysics Data System (ADS)

We review the conditions that are necessary for the perception of transparency and describe the spatiochromatic constraints for achromatic and chromatic transparent displays. These constraints can be represented by the convergence model and are supported by psychophysical data. We present an alternative representation of the constraints necessary for transparency perception that is based on an analogy with a model of colour constancy and the invariance of cone-excitation ratios. Recent psychophysical experiments are described that suggest that displays where the cone-excitation ratios are invariant produce a stronger impression of transparency than displays where the cone excitations are convergent. We argue that the spatial relations in an image are preserved when a Mondrian-like surface is partially covered by a transparent filter and therefore show an intriguing link between transparency perception and colour constancy. Finally, we describe experiments to relate the strength of the transparency percept with the number of unique patches in the image display. We find that the greater the number of surfaces in the display that are partially covered by a transparent filter the stronger the impression of transparency.

Westland, Stephen; da Pos, Osvaldo; Ripamonti, Caterina

2002-06-01

247

Zinc Oxide Transparent Thin Films For Optoelectronics  

NASA Astrophysics Data System (ADS)

The object of this body of work is to study the properties and suitability of zinc oxide thin films with a view to engineering them for optoelectronics applications, making them a cheap and effective alternative to indium tin oxide (ITO), the most used transparent conducting oxides in the industry. Initially, a study was undertaken to examine the behavior of silver contacts to ZnO and ITO during thermal processing, a step frequently used in materials processing in optoelectronics. The second study involved an attempt to improve the conductivity of ZnO films by inserting a thin copper layer between two ZnO layers. The Hall resistivity of the films was as low as 6.9x10 -5 O-cm with a carrier concentration of 1.2x10 22 cm-3 at the optimum copper layer thickness. The physics of conduction in the films has been examined. In order to improve the average visible transmittance, we replaced the copper layer with gold. The films were then found to undergo a seven orders of magnitude drop in effective resistivity from 200 O-cm to 5.2x10-5 O-cm The films have an average transmittance between 75% and 85% depending upon the gold thickness, and a peak transmittance of up to 93%. The best Haacke figure of merit was 15.1x10-3 O-1. Finally, to test the multilayer transparent electrodes on a device, ZnO/Au/ZnO (ZAZ) electrodes were evaluated as transparent electrodes for organic light-emitting devices (OLEDs). The electrodes exhibited substantially enhanced conductivity (about 8x10-5 O-cm) over conventional indium tin oxide (ITO) electrodes (about 3.2x10-5 O-cm). OLEDs fabricated with the ZAZ electrodes showed reduced leakage compared to control OLEDs on ITO and reduced ohmic losses at high current densities. At a luminance of 25000 cd/m2, the lum/W efficiency of the ZAZ electrode based device improved by 5% compared to the device on ITO. A normalized intensity graph of the colour output from the green OLEDs shows that ZAZ electrodes allow for a broader spectral output in the green wavelength region of peak photopic sensitivity compared to ITO. The results have implications for electrode choice in display technology.

Sivaramakrishnan, Karthik

248

Samus Counter Lifting Fixture  

SciTech Connect

A lifting fixture has been designed to handle the Samus counters. These counters are being removed from the D-zero area and will be transported off site for further use at another facility. This fixture is designed specifically for this particular application and will be transferred along with the counters. The future use of these counters may entail installation at a facility without access to a crane and therefore a lift fixture suitable for both crane and/or fork lift usage has been created The counters weigh approximately 3000 lbs. and have threaded rods extended through the counter at the top comers for lifting. When these counters were first handled/installed these rods were used in conjunction with appropriate slings and handled by crane. The rods are secured with nuts tightened against the face of the counter. The rod thread is M16 x 2({approx}.625-inch dia.) and extends 2-inch (on average) from the face of the counter. It is this cantilevered rod that the lift fixture engages with 'C' style plates at the four top comers. The strongback portion of the lift fixture is a steel rectangular tube 8-inch (vertical) x 4-inch x .25-inch wall, 130-inch long. 1.5-inch square bars are welded perpendicular to the long axis of the rectangular tube at the appropriate lift points and the 'C' plates are fastened to these bars with 3/4-10 high strength bolts -grade 8. Two short channel sections are positioned-welded-to the bottom of the rectangular tube on 40 feet centers, which are used as locators for fork lift tines. On the top are lifting eyes for sling/crane usage and are rated at 3500 lbs. safe working load each - vertical lift only.

Stredde, H.; /Fermilab

1998-05-27

249

The CLAS Start Counter  

SciTech Connect

The design, construction, and performance of a hexagonal-nose-cone shaped plastic scintillation counter system is described. This ''Start Counter'' is used as part of the trigger and to measure event start times for photon beam running with CLAS in Hall B at the Thomas Jefferson National Accelerator Facility. The Start Counter is constructed of three 3-mm thick coupled paddle scintillators and achieves a software-corrected time resolution of 260 ps. Each coupled-paddle scintillator operated without appreciable sagging up to {approx}1.2 MHz rate.

S. Taylor; S. Ahmad; J. Distelbrink; G. S. Mutchler; E. Smith; T. Smith

2001-08-01

250

GASEOUS SCINTILLATION COUNTER  

DOEpatents

A gaseous excitation counter for detecting the presence amd measuring the energy of subatomic particles and electromagnetic radiation is described. The counter includes a gas-tight chamber filled with an elemental gas capable of producing ultra-violet excitation quanta when irradiated with subatomic particles and electromagnetic radiation. The gas has less than one in a thousand parts ultra-violet absorbing contamination. When nuclear radiation ps present the ultra-violet light produced by the gas strikes a fluorescent material within the counter, responsive to produce visible excitation quanta, and photo-sensitive counting means detect the visible emission.

Eggler, C.; Huddleston, C.M.

1959-04-28

251

Talking about Transparency  

ERIC Educational Resources Information Center

|In his inaugural address, U.S. President Barack Obama linked the need to demonstrate accountability and transparency to the earning of trust. His connection of these dots is not surprising, since taxpayers often expect accountability and transparency from their governments, just as governments, donors, alumni, and students expect accountability…

Goldsmith, Rae

2009-01-01

252

Flexible and Transparent Memory: Non-Volatile Memory Based on Graphene Channel Transistor for Flexible and Transparent Electronics Applications  

Microsoft Academic Search

A Flexible and Transparent charge trap Memory (FTM) based on a single-layer graphene (SLG) channel with a ITO gate electrode was fabricated on a flexible and transparent poly-ethylene naphtalate (PEN) substrate. Triple high-k dielectric stacks Al2O3- AlOx-Al2O3 (AAA) were used as a data storage layer. The FTM shows memory characteristics with a memory window larger than 7V while maintaining ~80%

Sung Min Kim; Emil B. Song; Sejoon Lee; Jinfeng Zhou; Sunae Seo; David H. Seo; Kang L. Wang

2012-01-01

253

Two different features of ZnO: transparent ZnO:Ga electrodes for InGaN-LEDs and homoepitaxial ZnO films for UV-LEDs  

Microsoft Academic Search

We have used molecular beam epitaxy (MBE) to deposit gallium (Ga) doped ZnO (ZnO:Ga) films. The as-deposited ZnO:Ga films have worked as ohmic contacts for the p-type GaN layers without any kinds of post annealing process. The as-deposited ZnO:Ga films on a-plane sapphire substrates have resistivities of 2-4×10-4 Omegacm, and over 80 % transparency in the near-UV and visible wavelength

K. Nakahara; H. Yuji; K. Tamura; S. Akasaka; H. Tampo; S. Niki; A. Tsukazaki; A. Ohtomo; M. Kawasaki

2006-01-01

254

Over-the-Counter  

Center for Drug Evaluation (CDER)

... Over-the-Counter; Small Entity Compliance Guides, Organ-Specific Warnings: Internal Analgesic, Antipyretic, and Antirheumatic Drug Products for ... More results from www.fda.gov/drugs/guidancecomplianceregulatoryinformation/guidances

255

Shower counter resolution scaling  

SciTech Connect

The EM shower counter for the SDC detector has a resolution expression containing two stochastic terms plus a constant term. Recent measurements clarifying the sources of these terms are presented here. 3 refs., 4 figs.

Kirk, T.B.W.

1991-10-14

256

Gas Mixtures and Electrode Materials for Electroluminescence Detectors of Charged Particles.  

National Technical Information Service (NTIS)

The different gas mixtures (Ne, He, Ar, Xe and N sub 2 with acetone, benzene, athanol, methanol and toluene admixtures) and electrode materials (alluminium, copper, permalloy and carbon) for electroluminescent gas counter with plane-parallel electrodes ar...

S. V. Golovkin

1979-01-01

257

Temperature effect on the performance characteristics of beta rays open air corona streamer counter  

Microsoft Academic Search

Open air three electrode (point-grid-plane) corona streamer counter with a preamplification gap has been utilized for detecting weakly ionizing beta rays. This is based on the fact that when the primary electrons produced by beta rays are multiplied in the external preamplification gap, they form a trigger electron swarm before entering the counter, produce the same effect as the direct

Laila F. Fouad; Saher T. Mohamed El-Hazek

1996-01-01

258

Two different features of ZnO: transparent ZnO:Ga electrodes for InGaN-LEDs and homoepitaxial ZnO films for UV-LEDs  

NASA Astrophysics Data System (ADS)

We have used molecular beam epitaxy (MBE) to deposit gallium (Ga) doped ZnO (ZnO:Ga) films. The as-deposited ZnO:Ga films have worked as ohmic contacts for the p-type GaN layers without any kinds of post annealing process. The as-deposited ZnO:Ga films on a-plane sapphire substrates have resistivities of 2-4×10-4 ?cm, and over 80 % transparency in the near-UV and visible wavelength regions. The brightness of InGaN light-emitting diodes (LEDs) with ZnO:Ga p-contacts has doubled compared to LEDs with conventional Ni/Au semi-transparent p-contacts when measuring the brightness from right above the device surfaces. In addition, using MBE, we have grown homoepitaxial polar ZnO films on (000+1)-plane (+c-plane) ZnO substrates, and also grown non-polar ZnO films on (1-100)-plane (m-plane) and (11-20)-plane (a-plane) ZnO substrates. Growth temperatures have not affected nitrogen-doping levels for +c-axis oriented (Zn-polar) nitrogen doped ZnO (ZnO:N) films. The phenomena were quite different from that for (000-1)-axis (-c-axis) oriented (oxygen-polar) growth, where nitrogen concentrations in ZnO decrease with increasing growth temperatures. We have observed c-axis direction growth for both of m-axis and a-axis oriented films. Oxygen-rich growth conditions flatten surfaces for both m-axis and a-axis oriented films, and the surfaces of m-axis oriented ZnO films flatten with increasing growth temperatures. Nitrogen concentrations in m-axis oriented ZnO:N films have been independent on growth temperatures.

Nakahara, K.; Yuji, H.; Tamura, K.; Akasaka, S.; Tampo, H.; Niki, S.; Tsukazaki, A.; Ohtomo, A.; Kawasaki, M.

2006-03-01

259

Diagnosis of Diabetes in a Diabetic Patient's Urine and Blood Using a Combination Electrode with a Ubiquitous Handheld Analyzer  

Microsoft Academic Search

Glucose assay was conducted on untreated diabetic patient's urine and blood using a combination electrode (CE) whose sensor was interfaced with a newly constructed handheld voltammetry. The CE was prepared using the com- mon graphite pencil as a working electrode, handmade reference electrode, and platinum counter electrode, which were combined into one electrode system. The CE was optimized through cyclic

Suw Y. Ly

2009-01-01

260

Buried-channel CCD imaging arrays with tin-oxide transparent gates  

Microsoft Academic Search

The fabrication and performance of CCD imaging arrays with transparent gate tin-oxide electrodes will be presented. Imagers described will include 1 × 256 linear, 100 × 100 area and 29 × 9 TDI sensors.

David H. McCann; Alfred P. Turley; James A. Hall; John M. Walker; Richard A. Tracy; Marvin H. White; L. Thompson

1978-01-01

261

Production, Characteristics, and Reliability of Geiger-Müller Counters  

Microsoft Academic Search

A technique for the production of reliable Geiger-Müller counters is described. By the use of pure hydrogen gas and by cleaning the electrodes by sputtering in a glow discharge in hydrogen previous to filling the tubes with hydrogen gas, tubes with plateaus of 400 volts are produced. Copper, nickel, and tungsten have been found suitable for cathode cylinders while aluminum

O. S. Duffendack; H. Lifschutz; M. M. Slawsky

1937-01-01

262

A Dictionary for Transparency  

SciTech Connect

There are many terms that are used in association with the U.S. Defense Threat Reduction Agency (DTRA) Transparency Project associated with the Mayak Fissile Materials Storage Facility. This is a collection of proposed definitions of these terms.

Kouzes, Richard T.

2001-11-15

263

Stretchable, transparent, ionic conductors.  

PubMed

Existing stretchable, transparent conductors are mostly electronic conductors. They limit the performance of interconnects, sensors, and actuators as components of stretchable electronics and soft machines. We describe a class of devices enabled by ionic conductors that are highly stretchable, fully transparent to light of all colors, and capable of operation at frequencies beyond 10 kilohertz and voltages above 10 kilovolts. We demonstrate a transparent actuator that can generate large strains and a transparent loudspeaker that produces sound over the entire audible range. The electromechanical transduction is achieved without electrochemical reaction. The ionic conductors have higher resistivity than many electronic conductors; however, when large stretchability and high transmittance are required, the ionic conductors have lower sheet resistance than all existing electronic conductors. PMID:23990555

Keplinger, Christoph; Sun, Jeong-Yun; Foo, Choon Chiang; Rothemund, Philipp; Whitesides, George M; Suo, Zhigang

2013-08-30

264

Antimony electrodes  

Microsoft Academic Search

Antimony electrodes are clinically useful because of their low cost and simple construction; they have no glass to break. There is only a few hundred ohms resistance between an antimony pH electrode and the reference electrode so that the voltage generated can be recorded with simple low-impedance recorders linked to microcomputers. We used antimony pH electrodes with silver-silver chloride electrodes

Antone R. Opekun; J. Lacey Smith; David Y. Graham

1990-01-01

265

California Science Explorer Transparencies  

NSDL National Science Digital Library

This collection of transparencies features materials for life science, earth science, and physical sciences. The transparencies are downloadable and printable, or can be viewed on-screen. Earth Science topics include plate tectonics and the Earth's structure; landforms and weathering; water, hydrology, and weather; and ecosystems and food webs. Life science topics include, among others, evolution and the Earth's history, and structure and function in living things. Physical science topics include motion, forces, and energy; sound and light; and electricity and magnetism.

266

Welcoming transparency: some physicians find merit in online ratings.  

PubMed

This letter to the editor is in response to Wendy Budin's editorial, "Welcoming Transparency," published in the Volume 18, Number 2 (Spring 2009) issue of The Journal of Perinatal Education. As Dr. Budin noted, some individuals in the medical community want to counter consumer-led efforts to rate doctors' performance and find relevant health-care information online. Their opposition to such efforts is exemplified by extreme measures such as the "gag order" mentioned by Dr. Budin. However, a recent article published by Medscape reveals that some physicians understand and welcome the need for transparency in health care. PMID:20514126

Levine, Jacqueline

2009-01-01

267

Novel sputtering method for Pd-Al2O3 UV transparent conductive coatings  

Microsoft Academic Search

Transparent conductive layers like indium tin oxide (ITO) or zinc oxide, that are commonly used as signal electrodes of vidicon television tubes, have an absorption edge in the visible range (350-400 nm) and therefore are not transparent in the ultra-violet (UV). We have developed the Pd-Al2O3 thin film structure which is appropriate as a signal electrode for the vidicon operating

A. Axelevitch; G. Golan; E. Rabinovitch; R. Margolin

2000-01-01

268

Transparency for computer synthesized images  

Microsoft Academic Search

Simple transparency algorithms which assume a linear transparency over an entire surface are the type most often employed to produce computer synthesized images of transparent objects with curved surfaces. Although most of the images created with these algorithms do give the impression of transparency, they usually do not look realistic. One of the most serious problems is that the intensity

Douglas Scott Kay; Donald Greenberg

1979-01-01

269

Radiation effects on silver and zinc battery electrodes. II. July-October 1965  

Microsoft Academic Search

The study of the effects of radiation on silver and zinc electrodes was continued with specific attention being given to the silver electrode. Cadmium counter electrodes were used with the silver electrodes in the study pending the availability of suitable zinc electrodes. Material losses from irradiated silver electrodes of 3.0 g total weight averaged 60.2, 77.7, and 52.9 mg at

G. R. Argue; H. L. Recht; W. A. McCollum

1965-01-01

270

Needle-type multi-electrode array fabricated by MEMS technology for the hypodermic continuous glucose monitoring system  

Microsoft Academic Search

A needle-type multi-electrode array for the hypodermic continuous glucose monitoring sensor was fabricated using MEMS technology. The developed multielectrode sensor has 4 electrodes of two working(Pt) electrodes, one counter(Pt) electrode, and one reference(Ag\\/AgCl) electrode. Two working electrodes are for the enzyme and nonenzyme electrodes which measure glucose concentration and the background current(I0), respectively. The developed integrated sensor system is adequate

M. W. Jung; D. W. Kim; R. A. Jeong; H. C. Kim

2004-01-01

271

Countering Covert Aggression.  

National Technical Information Service (NTIS)

This note considers how the United States might better counter covert aggression. Among other issues, the study (1) examines the uses of terrorism, subversion, and insurgency as instruments of state policy; (2) analyzes the principal constraints on U.S. f...

S. T. Hosmer G. K. Tanham

1986-01-01

272

Electromagnetically Operated Counter  

DOEpatents

An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

Goldberg, H.D.; Goldberg, M.I.

1950-01-31

273

Fuel temperature counter  

Treesearch

We have developed for field use a new fuel temperature counter which can be ... has low power requirements, and will operate up to 2 weeks without attendance. It consists of three fuel temperature sensors, a pulse generator, a timer, and an ...

274

Microchip Coulter particle counter  

Microsoft Academic Search

This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (?CPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during operation. By sheathing of a nonconductive liquid on either side of an electrolyte, it is possible

U. D. Larsen; G. Blankenstein; J. Branebjerg

1997-01-01

275

Enzyme Electrode.  

National Technical Information Service (NTIS)

The patent application relates to an electrochemical device, and more particularly to an improved electrode structure for amperometric analysis of substances. Amperometric electrode sensors are known which include enzymes in their structure. Such devices ...

Guilbault

1973-01-01

276

Rh-doped SrTiO3 photocatalyst electrode showing cathodic photocurrent for water splitting under visible-light irradiation.  

PubMed

A Rh-doped SrTiO(3) (SrTiO(3):Rh) photocatalyst electrode that was readily prepared by pasting SrTiO(3):Rh powder onto a transparent indium tin oxide electrode gave a cathodic photocurrent under visible-light irradiation (? > 420 nm), indicating that the SrTiO(3):Rh photocatalyst electrode possessed p-type semiconductor character. The cathodic photocurrent increased with an increase in the amount of doped Rh up to 7 atom %. The incident-photon-to-current efficiency at 420 nm was 0.18% under an applied potential of -0.7 V vs Ag/AgCl for the SrTiO(3):Rh(7 atom %) photocatalyst electrode. The photocurrent was confirmed to be due to water splitting by analyzing the evolved H(2) and O(2). The water splitting proceeded with the application of an external bias smaller than 1.23 V versus a Pt counter electrode under visible-light irradiation and also using a solar simulator, suggesting that solar energy conversion should be possible with the present photoelectrochemical water splitting. PMID:21797261

Iwashina, Katsuya; Kudo, Akihiko

2011-08-05

277

Electrode compositions  

DOEpatents

An electrode composition is described for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C{sub 8}-C{sub 15} alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5--4.5 volts.

Block, J.; Fan, X.

1998-10-27

278

Electrode compositions  

DOEpatents

An electrode composition for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C.sub.8 -C.sub.15 alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5-4.5 volts.

Block, Jacob (Rockville, MD); Fan, Xiyun (Orange, TX)

1998-01-01

279

Transparent Armor for the New Standard in Transparent Battle Performance.  

National Technical Information Service (NTIS)

Armor Transparent Purchase Description (ATPD) 2352 revision P was issued in July 2008 to create a new standard for transparent armor aimed at improving battlefield performance, maintenance costs, equipment survivability, and general durability based on da...

D. Templeton J. Carberry K. Leighton T. Avery W. Serafin

2011-01-01

280

Transparency and selfhood: Utopia and the informed body.  

PubMed

One aspect of the development of a health-orientated consumer culture is the growth of self-screening and self-diagnosis among the lay public--e.g. over-the-counter diagnostic tests, computerized health assessments. DIY genetic tests. This trend is interpreted as the expression of a distinctively postmodern 'utopian' impulse. Postmodernity's inwardly directed gaze has replaced the communitarian vision of modernity. In the absence of overarching visions, the postmodern utopian telos becomes the attainment of a perfect. imperishable body. Somatopia is the collective expression of these privatized and personalized body projects. The accomplishment and authentication of these body projects necessitates the creation of a 'transparent body'. This 'transparent body' is enabled and constructed by developments in information and medical technologies. The political and health implications of the transparent, 'informed' body are explored. PMID:11824922

Chrysanthou, Marc

2002-02-01

281

Development of a Transparent Self Cleaning Dust Shield for Solar Panels  

Microsoft Academic Search

Development of a transparent electrodynamic shield to protect panels from dust deposition is described. The shield contains a clear panel with embed- ded parallel electrodes connected to a single-phase AC supply for producing an electromagnetic wave. The electromagnetic field produced by the electrodes on the surface of the panel repels dust particles that have already deposited on the panel surface,

R. A. Sims; A. S. Biris; J. D. Wilson; C. U. Yurteri; M. K. Mazumder; C. I. Calle; C. R. Buhler

282

Transparent spinel development  

NASA Astrophysics Data System (ADS)

The optical and mechanical properties of polycrystalline MgAl2O4 spinel make this material of interest for transparent armor and for window and dome applications in the 0.3 micrometers to 5.5 micrometers range. Spinel was briefly produced commercially, and qualified for a range of dome and window applications in the early 1990's. Since 1993 however, there has been no commercial producer and consequently the interest in the application of spinel has waned. This paper summarizes development efforts by Technology Assessment and Transfer (TA&T) to fabricate transparent spinel with high optical quality for both transparent armor, and a selection of window and dome applications. A cooperative research and development agreement between TA&T and the US Army Research Laboratory is focused at optimizing processing parameters to maximize strength and transparency while minimizing the costs for fabrication by the hot-press/HIP approach. Present interest is in fabricating large armor panels of spinel up to 15 inches square and 0.5 inches thick, and in the fabrication of thinner windows and domes with the view to establishing TA&T as a commercial supplier of spinel in the near future.

Patterson, Mark; Caiazza, Jenni E.; Roy, Donald W.

2000-10-01

283

Transparent Ceramic Armor.  

National Technical Information Service (NTIS)

A transparent ceramic armor system has been developed and ballistically tested at Sandia Laboratories. It consists of a thin sapphire crystal front plate supported by a 3.5-cm Pyrex glass laminate and 2.5- to 1.26-cm polycarbonate laminate. Typically, sap...

C. P. Ballard

1978-01-01

284

Terminal Transparent Display Language.  

National Technical Information Service (NTIS)

This is the final technical report for the Terminal Oriented Support System (TOSS) Terminal Transparent Display Language (TTDL) produced under the provisions of RADC contract number F30602-73-C-0379. TTDL has been implemented and is integrated with the TO...

C. Y. Bumgardner C. Krebs T. Northwood T. Reiss J. Lindsey

1976-01-01

285

Remote Monitoring Transparency Program  

SciTech Connect

The objective of the Remote Monitoring Transparency Program is to evaluate and demonstrate the use of remote monitoring technologies to advance nonproliferation and transparency efforts that are currently being developed by Russia and the United States without compromising the national security to the participating parties. Under a lab-to-lab transparency contract between Sandia National Laboratories (SNL) and the Kurchatov Institute (KI RRC), the Kurchatov Institute will analyze technical and procedural aspects of the application of remote monitoring as a transparency measure to monitor inventories of direct- use HEU and plutonium (e.g., material recovered from dismantled nuclear weapons). A goal of this program is to assist a broad range of political and technical experts in learning more about remote monitoring technologies that could be used to implement nonproliferation, arms control, and other security and confidence building measures. Specifically, this program will: (1) begin integrating Russian technologies into remote monitoring systems; (2) develop remote monitoring procedures that will assist in the application of remote monitoring techniques to monitor inventories of HEU and Pu from dismantled nuclear weapons; and (3) conduct a workshop to review remote monitoring fundamentals, demonstrate an integrated US/Russian remote monitoring system, and discuss the impacts that remote monitoring will have on the national security of participating countries.

Sukhoruchkin, V.K.; Shmelev, V.M.; Roumiantsev, A.N. [Gosudarstvennyj Komitet po Ispol`zovaniyu Atomnoj Ehnergii SSSR, Moscow (Russian Federation). Inst. Atomnoj Ehnergii

1996-08-01

286

Capitalism and transparency  

Microsoft Academic Search

Purpose – The purpose of this paper is to critically examine the international NGO Transparency International's (TI) role in combating corruption, focusing particularly on TI's response to the global financial crisis of 2008. Design\\/methodology\\/approach – The paper is based on a review of scholarly articles, newspaper reports, and TI publications. Findings – The paper concludes that TI's uncritical approach to

Jonathan Murphy

2011-01-01

287

Mars Dust Counter  

Microsoft Academic Search

In order to unveil the presence and characteristics of Martian dust ring\\/torus, Mars Dust Counter (MDC) is aboard ISAS's spacecraft PLANET-B, which will be launched in 1998 summer and investigate the upper atmosphere and surrounding environment of Mars between 1999 and 2001. MDC PLANET-B is an improved version of impact-ionization dust detectors aboard HITEN and BREMSAT. It weighs only 730

E. Igenbergs; S. Sasaki; R. Münzenmayer; H. Ohashi; G. Färber; F. Fischer; A. Fujiwara; A. Glasmachers; E. Grün; Y. Hamabe; H. Iglseder; D. Klinge; H. Miyamoto; T. Mukai; W. Naumann; K. Nogami; G. Schwehm; H. Svedhem; K. Yamakoshi

1998-01-01

288

Countering Hostile Forensic Techniques  

NASA Astrophysics Data System (ADS)

Digital forensic investigations can be subverted by hostile forensic techniques and tools. This paper examines various hostile forensic techniques, including the exploitation of vulnerabilities in standard forensic procedures and denial of service attacks on forensic tools during imaging and analysis. Several techniques for concealing evidence within file systems and external to file systems are highlighted. In addition, strategies for countering hostile forensic techniques and tools are discussed.

Piper, Scott; Davis, Mark; Shenoi, Sujeet

289

Magnetron cathodes in plasma electrode Pockels cells  

DOEpatents

Magnetron cathodes, which produce high current discharges, form greatly improved plasma electrodes on each side of an electro-optic crystal. The plasma electrode has a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the plasma is transparent. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. A typical configuration utilizes helium at 50 millitorr operating pressure and 2 kA discharge current. The magnetron cathode produces a more uniform plasma and allows a reduced operating pressure which leads to lower plasma resistivity and a more uniform charge on the crystal. 5 figs.

Rhodes, M.A.

1995-04-25

290

Magnetron cathodes in plasma electrode pockels cells  

DOEpatents

Magnetron cathodes, which produce high current discharges, form greatly improved plasma electrodes on each side of an electro-optic crystal. The plasma electrode has a low pressure gas region on both sides of the crystal. When the gas is ionized, e.g., by a glow discharge in the low pressure gas, the plasma formed is a good conductor. The gas electrode acts as a highly uniform conducting electrode. Since the plasma is transparent to a high energy laser beam passing through the crystal, the plasma is transparent. A crystal exposed from two sides to such a plasma can be charged up uniformly to any desired voltage. A typical configuration utilizes helium at 50 millitorr operating. pressure and 2 kA discharge current. The magnetron cathode produces a more uniform plasma and allows a reduced operating pressure which leads to lower plasma resistivity and a more uniform charge on the crystal.

Rhodes, Mark A. (Pleasanton, CA)

1995-01-01

291

Transparent metal oxide nanowire transistors  

NASA Astrophysics Data System (ADS)

With the features of high mobility, a high electric on/off ratio and excellent transparency, metal oxide nanowires are excellent candidates for transparent thin-film transistors, which is one of the key technologies to realize transparent electronics. This article provides a comprehensive review of the state-of-the-art research activities that focus on transparent metal oxide nanowire transistors. It begins with the brief introduction to the synthetic methods for high quality metal oxide nanowires, and the typical nanowire transfer and printing techniques with emphasis on the simple contact printing methodology. High performance transparent transistors built on both single nanowires and nanowire thin films are then highlighted. The final section deals with the applications of transparent metal oxide nanowire transistors in the field of transparent displays and concludes with an outlook on the current perspectives and future directions of transparent metal oxide nanowire transistors.

Chen, Di; Liu, Zhe; Liang, Bo; Wang, Xianfu; Shen, Guozhen

2012-05-01

292

Solution processed zinc oxide nanopyramid/silver nanowire transparent network films with highly tunable light scattering properties  

NASA Astrophysics Data System (ADS)

Metal nanowire transparent networks are promising replacements to indium tin oxide (ITO) transparent electrodes for optoelectronic devices. While the transparency and sheet resistance are key metrics for transparent electrode performance, independent control of the film light scattering properties is important to developing multifunctional electrodes for improved photovoltaic absorption. Here we show that controlled incorporation of ZnO nanopyramids into a metal nanowire network film affords independent, highly tunable control of the scattering properties (haze) with minimal effects on the transparency and sheet resistance. Varying the zinc oxide/silver nanostructure ratios prior to spray deposition results in sheet resistances, transmission (600 nm), and haze (600 nm) of 6-30 ? ?-1, 68-86%, and 34-66%, respectively. Incorporation of zinc oxide nanopyramid scattering agents into the conducting nanowire mesh has a negligible effect on mesh connectivity, providing a straightforward method of controlling electrode scattering properties. The decoupling of the film scattering power and electrical characteristics makes these films promising candidates for highly scattering transparent electrodes in optoelectronic devices and can be generalized to other metal nanowire films as well as carbon nanotube transparent electrodes.

Mehra, Saahil; Christoforo, Mark G.; Peumans, Peter; Salleo, Alberto

2013-05-01

293

Solution processed zinc oxide nanopyramid/silver nanowire transparent network films with highly tunable light scattering properties.  

PubMed

Metal nanowire transparent networks are promising replacements to indium tin oxide (ITO) transparent electrodes for optoelectronic devices. While the transparency and sheet resistance are key metrics for transparent electrode performance, independent control of the film light scattering properties is important to developing multifunctional electrodes for improved photovoltaic absorption. Here we show that controlled incorporation of ZnO nanopyramids into a metal nanowire network film affords independent, highly tunable control of the scattering properties (haze) with minimal effects on the transparency and sheet resistance. Varying the zinc oxide/silver nanostructure ratios prior to spray deposition results in sheet resistances, transmission (600 nm), and haze (600 nm) of 6-30 ? ?(-1), 68-86%, and 34-66%, respectively. Incorporation of zinc oxide nanopyramid scattering agents into the conducting nanowire mesh has a negligible effect on mesh connectivity, providing a straightforward method of controlling electrode scattering properties. The decoupling of the film scattering power and electrical characteristics makes these films promising candidates for highly scattering transparent electrodes in optoelectronic devices and can be generalized to other metal nanowire films as well as carbon nanotube transparent electrodes. PMID:23575765

Mehra, Saahil; Christoforo, Mark G; Peumans, Peter; Salleo, Alberto

2013-05-21

294

How transparent are central banks?  

Microsoft Academic Search

Central bank transparency has become the topic of a lively public and academic debate on monetary policy. However, this has been complicated by the fact that transparency is a qualitative concept that is hard to measure. This paper proposes an index for the transparency of monetary policy that comprises the political, economic, procedural, policy and operational aspects of central banking.

Sylvester C. W. Eijffinger; Petra M. Geraats

2006-01-01

295

Patternable transparent carbon nanotube films for electrochromic devices  

NASA Astrophysics Data System (ADS)

This paper reports the application of transparent single walled carbon nanotube films on polyethylene terephthalate as flexible electrodes in electrochromic devices using polyaniline as the active layer, where Sn-doped In2O3 on plastic is not suitable due to its high sensitivity to acids. Patterning of nanotube films with resolution of 50 ?m is achieved by simply using the transfer printing method based on polydimethylsiloxane stamps. The combination of high optical transparency, low sheet resistance, robust mechanical and environmental stabilities, and ease of patterning of nanotube films meets the requirements for flexible voltage-driven type of displays.

Hu, Liangbing; Gruner, George; Li, Dan; Kaner, Richard B.; Cech, Jiri

2007-01-01

296

Reference Electrodes  

NASA Astrophysics Data System (ADS)

In most electrochemical measurements, it is necessary to keep one of the electrodes in an electrochemical cell at a constant potential. This so-called reference electrode allows control of the potential of a working electrode (e.g. in voltammetry) or the measurement of an indicator electrode (e.g. in potentiometry, see Chap. II.9). The standard hydrogen electrode plays the role of a basic reference element in electrochemical devices; however, in practice, it is difficult to handle. Therefore, secondary reference electrodes are preferred in most experiments. A secondary reference electrode must fulfil the following criteria: (i) it should be chemically and electrochemically reversible, i.e. its potential is governed by the Nernst equation and does not change in time; (ii) the potential must remain almost constant when a small current passes through the electrode and reverse to its original value after such small current flow (i.e. a non-polarisable electrode); and (iii) the thermal coefficient of potential should be small.

Kahlert, Heike

297

Transparent ceramic armor  

Microsoft Academic Search

A transparent ceramic armor system has been developed and ballistically tested at Sandia Laboratories. It consists of a thin sapphire crystal front plate supported by a 3.5-cm Pyrex glass laminate and 2.5- to 1.26-cm polycarbonate laminate. Typically, sapphire plates with a thickness of 0.06 to 0.08 cm may be used with this design to provide protection against caliber .30 armor-piercing

Ballard; C. P. Jr

1978-01-01

298

Transparent spinel development  

Microsoft Academic Search

The optical and mechanical properties of polycrystalline MgAl2O4 spinel make this material of interest for transparent armor and for window and dome applications in the 0.3 micrometers to 5.5 micrometers range. Spinel was briefly produced commercially, and qualified for a range of dome and window applications in the early 1990's. Since 1993 however, there has been no commercial producer and

Mark Patterson; Jenni E. Caiazza; Donald W. Roy

2000-01-01

299

Transparency -- Some observations  

SciTech Connect

The increasingly popular term transparency has been used throughout the IAEA Safeguards Symposium to mean many things to many people. It has rather little utility as a catch-all term or buzz word. A precise definition of transparency is in order. In this paper, transparency is the provision to the IAEA of additional information for which the IAEA has an identified use and includes any associated increased IAEA access to sue the information. In 1993, the IAEA Board endorsed very specific proposals for provision to the IAEA of additional information on international nuclear transfers. It also made specific decisions on verification in the context of tis earlier confirmation of the very sweeping access rights for special inspections outlined by the director general. Additional information to the IAEA has two potential practical uses. First, it could help identify inconsistencies within the entirety of the information available to the IAEA, including information from inspections. These inconsistencies could be an indication of some violation of safeguards undertakings. Second, a declaration of the Member State could facilitate IAEA interpretation of analyses of other information or facilitate resolution of ambiguities. In these respects, additional information is not different from currently used information. When considering seeking specific additional information, the IAEA must balance the potential contribution of the information and its expected costs.

Houck, F.

1994-07-01

300

EDITORIAL: On display with transparent conducting films On display with transparent conducting films  

NASA Astrophysics Data System (ADS)

Transparent conducting films were already featuring in scientific literature over one hundred years ago. In 1894 Aryton and Mather described a conducting varnish for coating the screens of electric apparatus so they would not charge when accidentally brushed by a coat sleeve or other material [1]. Their method began with a similar approach to that used to make savoury jellies; by dissolving gelatine in vinegar, after which less palatable ingredients were incorporated including sulphuric acid and an antisulphuric enamel. While the search for transparent conducting films continued to attract other researchers, the same problem remained: the transparency would be compromised if the film was too thick, and the conductivity would be compromised if the film was too thin. In the early 1950s Gillham and Preston reported that thin gold films sputtered on bismuth oxide and heated resulted in a material that successfully combined the previously mutually exclusive properties of transparency and conductivity [2]. Other oxide films were also found to favourably combine these properties, including tin oxide, as reported by Ishiguro and colleagues in Japan in 1958 [3]. Today tin oxide doped with indium (ITO) has become the industry standard for transparent conducting films in a range of applications including photovoltaic technology and displays. It is perhaps the mounting ubiquity of electronic displays as a result of the increasingly digitised and computerised environment of the modern day world that has begun to underline the main drawback of ITO: expense. In this issue, a collaboration of researchers in Korea present an overview of graphene as a transparent conducting material with the potential to replace ITO in a range of electronic and optoelectronic applications [4]. One of the first innovations in optical microscopy was the use of dyes. This principle first came into practice with the use of ultraviolet light to reveal previously indistinguishable features. As explained by a researcher in the early 1930s, 'It is obvious that if the dyes used for selective staining in ordinary microscopical work are supplemented by substances which cause a particular detail of the structure to fluoresce with a specific colour in ultraviolet light, then many strings will be added to the bow of the practical microscopist' [3]. More recently, emphasis on the role of plasmons—collective oscillations of electrons in nanoscale metal structures—has received considerable research attention. Plasmons enhance the local electromagnetic field and can lead to increased fluorescence rates from nearby fluorophores depending on the efficiency of the counteracting process, non-radiative transfer [4]. Flat ITO films have been used extensively in photovoltaic studies as transparent electrodes [5]. Over the past few years, nanowire structures have recently been used to increase the surface area of the interface between dye and oxide in dye-sensitized solar cells [6]. A collaboration of researchers in China and Australia has recently extended the innovation of the nanowire structure to the ITO electrode [7]. Using cyclic voltammetry the researchers confirmed that using a 3D ITO-nanowire electrode significantly enhanced the reaction current. Despite its attractive properties, alternatives to ITO are now in high demand. The rise in devices requiring flat electronic displays has begun to overwhelm the legitimacy of using such a rare element as indium for transparent conducting films. ITO is also brittle, causing problems for flexible displays. Films of carbon nanotubes have been proposed for transparent conducting films but improvements to the sheet resistance are needed before they can compete with the performance of ITO. The effects of HNO3 treatment on the resistivity of carbon nanotube films has attracted some debate in the community, and stimulated the work of Ji-Beom Yoo and colleagues in Korea [8]. Their results suggest that p-type doping has a larger effect on the sheet resistance of HNO3 treated carbon-nanotube films than the removal of residual N-methylpy

Demming, Anna

2012-03-01

301

Prospects of graphene electrodes in photovoltaics  

NASA Astrophysics Data System (ADS)

Transparent conductors (TCs) are becoming extremely popular in many different electronic applications such as touch panels, displays, light emitting devices, light sensors and solar cells. The commonly used electrode in these applications is Indium Tin Oxide (ITO). However, the cost of ITO is increasing rapidly due to the limited supply of Indium. Other issues such as lack of flexibility and cost of the deposition process make ITO less favorable in transparent electrode applications. Graphene has been under exploration as an alternative material for TC applications in the recent years. Graphene based TCs have been shown experimentally to exhibit promising electrical and optical properties. In this paper, the prospects of graphene for transparent conductors in photovoltaics are discussed. The recent advancements in this field as well as the theoretical predictions and possible pathways for improvements are presented. In the process section, we discuss methods to synthesize few-layer graphene (FLG) with high quality in a controllable manner.

Khatami, Yasin; Liu, Wei; Kang, Jiahao; Banerjee, Kaustav

2013-09-01

302

Low latency counter event indication  

DOEpatents

A hybrid counter array device for counting events with interrupt indication includes a first counter portion comprising N counter devices, each for counting signals representing event occurrences and providing a first count value representing lower order bits. An overflow bit device associated with each respective counter device is additionally set in response to an overflow condition. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits. An operatively coupled control device monitors each associated overflow bit device and initiates incrementing a second count value stored at a corresponding memory location in response to a respective overflow bit being set. The incremented second count value is compared to an interrupt threshold value stored in a threshold register, and, when the second counter value is equal to the interrupt threshold value, a corresponding "interrupt arm" bit is set to enable a fast interrupt indication. On a subsequent roll-over of the lower bits of that counter, the interrupt will be fired.

Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

2008-09-16

303

Liquid Crystal Lens with Spherical Electrode  

NASA Astrophysics Data System (ADS)

The variable focusing function of a liquid crystal lens (LCL) with a spherical electrode is demonstrated. One electrode is a transparent film of indium tin oxide (ITO) coated on the spherical surface of a plano-convex glass lens that is placed on a planar liquid crystal cell. The lower substrate of the cell is also coated with an ITO film acting as another electrode. A nonuniform electric field nearly symmetrical about the central line produces a gradient distribution of refractive index. The cell therefore behaves like an optical lens. The LCL exhibits good optical properties, and can be of any size, and its diopter is a function of the applied voltage.

Wang, Bin; Ye, Mao; Honma, Michinori; Nose, Toshiaki; Sato, Susumu

2002-11-01

304

Tuning the conductance of molecular junctions: Transparent versus tunneling regimes  

NASA Astrophysics Data System (ADS)

We present a theoretical study of the transport characteristics of molecular junctions, where first-row diatomic molecules are attached to (001) gold and platinum electrodes. We find that the conductance of all of these junctions is on the order of the conductance quantum unit G0 , spelling out that they belong to the transparent regime. We further find that the transmission coefficients show wide plateaus as a function of the energy, instead of the usual sharp resonances that signal the molecular levels in the tunneling regime. We use Caroli’s model to show that this is a rather generic property of the transparent regime of a junction, which is driven by a strong effective coupling between the delocalized molecular levels and the conduction channels at the electrodes. We analyze the transmission coefficients and chemical bonding of gold/benzene and gold/benzene-dithiolate junctions to understand why the latter show large resistances while the former are highly conductive.

Ferrer, J.; García-Suárez, V. M.

2009-08-01

305

Space and power efficient hybrid counters array  

DOEpatents

A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

2009-05-12

306

The transparency of aging.  

PubMed

This article is not meant to provide answers but to provoke thinking related to the questions we should be asking about the ethical personhood of aging adults. Are we covering over the rich opportunities to learn from their stories with an invisible cloak of transparency? Health care professionals have a moral obligation to rethink the assumptions that underlie their definitions of quality of life in aging. We cannot know what should be done unless we learn to listen to the life stories of aging people. This may even help us to see what is most real. PMID:17396715

Sorrell, Jeanne M

2007-03-01

307

Hydrogel loaded active layer in pressure tolerant gas diffusion electrodes  

SciTech Connect

This patent describes an electrochemical cell. It comprises a gas diffusion electrode comprising an electronically conductive and electrochemically active porous body defining respective mutually exclusive gas and electrolyte contacting surfaces, with a substantially gas impermeable material filling at least a portion of the pore volume of the body so as to prevent gas passage therethrough, the material comprising an electrolyte-insoluble, ionomeric ionically conductive hydrophilic hydrogel formed by coprecipitation between at least first and second precursor polymers, a counter electrode spaced from the gas diffusion electrode; a first compartment having a liquid electrolyte contained therein, the liquid electrolyte being in contact with the counter electrode, the liquid electrolyte also being in contact with the electrolyte contacting surface of the gas diffusion electrode, wherein the electrolyte is an alkaline aqueous electrolyte; a second compartment having a gas therein, the gas in the second compartment being in contact with the gas contacting surface of the gas diffusion electrode but not in contact with the electrolyte contacting surface of the gas diffusion electrode; and, circuit connections between the gas diffusion electrode and the counter electrode.

Hossain, M.S.; Gordon, A.Z.; Yaeger, E.B.; Tryk, D.A.

1992-03-03

308

Liquid electrode  

DOEpatents

A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

Ekechukwu, A.A.

1994-07-05

309

Counter-Learning under Oppression  

ERIC Educational Resources Information Center

|This qualitative study utilized the method of narrative analysis to explore the counter-learning process of an oppressed Kurdish woman from Turkey. Critical constructivism was utilized to analyze counter-learning; Frankfurt School-based Marcusian critical theory was used to analyze the sociopolitical context and its impact on the oppressed. Key…

Kucukaydin, Ilhan

2010-01-01

310

Counter-Learning under Oppression  

ERIC Educational Resources Information Center

This qualitative study utilized the method of narrative analysis to explore the counter-learning process of an oppressed Kurdish woman from Turkey. Critical constructivism was utilized to analyze counter-learning; Frankfurt School-based Marcusian critical theory was used to analyze the sociopolitical context and its impact on the oppressed. Key…

Kucukaydin, Ilhan

2010-01-01

311

Ferromagnetic planar Josephson junction with transparent interfaces: a ? junction proposal.  

PubMed

We calculate the current-phase relation of a planar Josephson junction with a ferromagnetic weak link located on top of a thin normal metal film. Following experimental observations we assume transparent superconductor-ferromagnet interfaces. This provides the best interlayer coupling and a low suppression of the superconducting correlations penetrating from the superconducting electrodes into the ferromagnetic layer. We show that this Josephson junction is a promising candidate for experimental ? junction realization. PMID:23636963

Heim, D M; Pugach, N G; Kupriyanov, M Yu; Goldobin, E; Koelle, D; Kleiner, R

2013-05-02

312

Ferromagnetic planar Josephson junction with transparent interfaces: a ? junction proposal  

NASA Astrophysics Data System (ADS)

We calculate the current-phase relation of a planar Josephson junction with a ferromagnetic weak link located on top of a thin normal metal film. Following experimental observations we assume transparent superconductor–ferromagnet interfaces. This provides the best interlayer coupling and a low suppression of the superconducting correlations penetrating from the superconducting electrodes into the ferromagnetic layer. We show that this Josephson junction is a promising candidate for experimental ? junction realization.

Heim, D. M.; Pugach, N. G.; Kupriyanov, M. Yu; Goldobin, E.; Koelle, D.; Kleiner, R.

2013-05-01

313

Healthcare transparency: opportunity or mirage  

Microsoft Academic Search

Purpose – Healthcare is an ever-growing segment of the American economy. Transparency facilitates better decision-making and better outcomes measures. The purpose of this paper is to present the human and economic results of increasing transparency. Design\\/methodology\\/approach – The ASIMP Working Group on Healthcare Transparency represents a diverse yet conscilient group of practitioners, researchers, regulators, economists, and academics. Given the need

Russell Jaffe; Robert A. Nash; Richard Ash; Norman Schwartz; Robert Corish; Tammy Born; Harold Lazarus

2006-01-01

314

Wetting transparency of graphene.  

PubMed

We report that graphene coatings do not significantly disrupt the intrinsic wetting behaviour of surfaces for which surface-water interactions are dominated by van der Waals forces. Our contact angle measurements indicate that a graphene monolayer is wetting-transparent to copper, gold or silicon, but not glass, for which the wettability is dominated by short-range chemical bonding. With increasing number of graphene layers, the contact angle of water on copper gradually transitions towards the bulk graphite value, which is reached for ~6 graphene layers. Molecular dynamics simulations and theoretical predictions confirm our measurements and indicate that graphene's wetting transparency is related to its extreme thinness. We also show a 30-40% increase in condensation heat transfer on copper, as a result of the ability of the graphene coating to suppress copper oxidation without disrupting the intrinsic wettability of the surface. Such an ability to independently tune the properties of surfaces without disrupting their wetting response could have important implications in the design of conducting, conformal and impermeable surface coatings. PMID:22266468

Rafiee, Javad; Mi, Xi; Gullapalli, Hemtej; Thomas, Abhay V; Yavari, Fazel; Shi, Yunfeng; Ajayan, Pulickel M; Koratkar, Nikhil A

2012-01-22

315

Subdural Electrodes  

PubMed Central

Subdural electrodes are frequently used to aid in the neurophysiological assessment of patients with intractable seizures. We review the indications for these, their uses for localizing epileptogenic regions and for localizing cortical regions supporting movement, sensation, and language.

Lesser, Ronald P.; Crone, Nathan E.; Webber, W.R.S.

2010-01-01

316

Evaluation of Solution-Processed Reduced Graphene Oxide Films as Transparent Conductors  

Microsoft Academic Search

Processable, single-layered graphene oxide (GO) is an intriguing nanomaterial with tremendous potential for electronic applications. We spin-coated GO thin-films on quartz and characterized their sheet resistance and optical transparency using different reduction treatments. A thermal graphitization procedure wasmosteffective,producingfilmswithsheetresistancesaslowas102103\\/squarewith80%transmittance for 550 nm light. Our experiments demonstrate solution-processed GOfilms have potential as transparent electrodes.

Héctor A. Becerril; Jie Mao; Zunfeng Liu; Randall M. Stoltenberg; Zhenan Bao; Yongsheng Chen

2008-01-01

317

A portable neutron coincidence counter  

SciTech Connect

Pacific Northwest National Laboratory has designed and constructed a prototype portable neutron coincidence counter intended for use in a variety of applications, such as the verification and inspection of weapons components, safety measurements for novel and challenging situations, portable portal deployment to prevent the transportation of fissile materials, uranium enrichment measurements in hard-to-reach locations, waste assays for objects that cannot be measured by existing measurement systems, and decontamination and decommissioning. The counting system weighs less than 40 kg and is composed of parts each weighing no more than 5 kg. In addition, the counter`s design is sufficiently flexible to allow rapid, reliable assembly around containers of nearly arbitrary size and shape. The counter is able to discern the presence of 1 kg of weapons-grade plutonium within an ALR-8 (30-gal drum) in roughly 100 seconds and 10 g in roughly 1000 seconds. The counter`s electronics are also designed for maximum adaptability, allowing operation under a wide variety of circumstances, including exposure to gamma-ray fields of 1 R/h. This report provides a detailed review of the design and construction process. Finally, preliminary experimental measurements that confirm the performance capabilities of this counter are discussed. 6 refs., 18 figs., 3 tabs.

Peurrung, A.J.; Bowyer, S.M.; Craig, R.A.; Dudder, G.B.; Knopf, M.A.; Panisko, M.E.; Reeder, P.L.; Stromswold, D.C.; Sunberg, D.S.

1996-11-01

318

Plasmonic graphene transparent conductors.  

PubMed

Plasmonic graphene is fabricated using thermally assisted self-assembly of silver nanoparticles on graphene. The localized surface-plasmonic effect is demonstrated with the resonance frequency shifting from 446 to 495 nm when the lateral dimension of the Ag nanoparticles increases from about 50 to 150 nm. Finite-difference time-domain simulations are employed to confirm the experimentally observed light-scattering enhancement in the solar spectrum in plasmonic graphene and the decrease of both the plasmonic resonance frequency and amplitude with increasing graphene thickness. In addition, plasmonic graphene shows much-improved electrical conductance by a factor of 2-4 as compared to the original graphene, making the plasmonic graphene a promising advanced transparent conductor with enhanced light scattering for thin-film optoelectronic devices. PMID:22392746

Xu, Guowei; Liu, Jianwei; Wang, Qian; Hui, Rongqing; Chen, Zhijun; Maroni, Victor A; Wu, Judy

2012-03-01

319

Transparency in psychiatric care.  

PubMed

Transparency in medical care is emerging as a new standard. In the United States, patients have always been able to access to their chart in accordance with the Health Insurance Portability and Accountability Act (HIPAA), established in 1996. Such access, nevertheless, can be time consuming and burdensome. Among the many provisions afforded by HIPAA are the security and privacy of health data. Physicians are recently coming to realize the benefits enjoyed by patients and the healthcare system when the information in a patient's chart is made available in real-time. Psychiatrists often find the concept of revealing their progress notes, however, quite provocative and controversial. In these evolving times, it is important for psychiatrists to recognize the potential consequences and advantages of sharing their progress notes with patients. This review provides guidelines for psychiatrists to follow regarding proper documentation of progress notes and how to successfully share that information with patients. PMID:22981058

Farrell, Helen M

2012-08-21

320

Plasmonic graphene transparent conductors.  

SciTech Connect

Plasmonic graphene is fabricated using thermally assisted self-assembly of silver nanoparticles on graphene. The localized surface-plasmonic effect is demonstrated with the resonance frequency shifting from 446 to 495 nm when the lateral dimension of the Ag nanoparticles increases from about 50 to 150 nm. Finite-difference time-domain simulations are employed to confirm the experimentally observed light-scattering enhancement in the solar spectrum in plasmonic graphene and the decrease of both the plasmonic resonance frequency and amplitude with increasing graphene thickness. In addition, plasmonic graphene shows much-improved electrical conductance by a factor of 2-4 as compared to the original graphene, making the plasmonic graphene a promising advanced transparent conductor with enhanced light scattering for thin-film optoelectronic devices.

Xu, G.; Liu, J.; Wang, Q.; Hui, R.; Chen, Z.; Maroni, V. A.; Wu, J. (Materials Science Division); (Univ. Kansas)

2012-01-01

321

High resolution time interval counter  

NASA Astrophysics Data System (ADS)

In recent years, we have developed two types of high resolution, multi-channel time interval counters. In the NIST two-way time transfer MODEM application, the counter is designed for operating primarily in the interrupt-driven mode, with 3 start channels and 3 stop channels. The intended start and stop signals are 1 PPS, although other frequencies can also be applied to start and stop the count. The time interval counters used in the NIST Frequency Measurement and Analysis System are implemented with 7 start channels and 7 stop channels. Four of the 7 start channels are devoted to the frequencies of 1 MHz, 5 MHz or 10 MHz, while triggering signals to all other start and stop channels can range from 1 PPS to 100 kHz. Time interval interpolation plays a key role in achieving the high resolution time interval measurements for both counters. With a 10 MHz time base, both counters demonstrate a single-shot resolution of better than 40 ps, and a stability of better than 5 x 10(exp -12) (sigma(sub chi)(tau)) after self test of 1000 seconds). The maximum rate of time interval measurements (with no dead time) is 1.0 kHz for the counter used in the MODEM application and is 2.0 kHz for the counter used in the Frequency Measurement and Analysis System. The counters are implemented as plug-in units for an AT-compatible personal computer. This configuration provides an efficient way of using a computer not only to control and operate the counters, but also to store and process measured data.

Zhang, Victor S.; Davis, Dick D.; Lombardi, Michael A.

1995-05-01

322

The Student Dust Counter  

NASA Astrophysics Data System (ADS)

This talk will describe the scientific goals, the technical, and the human challenges of the Student Dust Counter (SDC) experiment for the New Horizons Mission to Pluto. CU's Laboratory for Atmospheric and Space Physics (LASP) organized a team of students to design, fabricate, test, calibrate, and fly SDC, one of seven science instruments onboard New Horizons. The student team was responsible for all phases of this development under the supervision of LASP professionals. Both undergraduate and graduate students worked on this project, representing a variety of disciplines, including Electrical and Mechanical Engineering, Computer Science, Physics, Journalism, and Business. The SDC project is part of the EPO effort of the New Horizons mission. Though it is a student project, the requirements for passing all standard NASA milestones for reviews were identical to other experiments. The students performed at a professional level and SDC was delivered on time and within budget. It is now integrated to the spacecraft awaiting the scheduled launch in January of 2006. To date, SDC provided a group of about 20 students an opportunity to learn first hand how to build instruments, and graduate with years of experience in space exploration.

Horanyi, M.; Bagenal, F.; Finley, T.; Christensen, F.; Holland, G.; Bryant, C.; Bunch, N.; Neeland, M.; Chanthawanich, T.; Fernandez, A.; Hoxie, V.; Jenkins, A.; Vaudrin, C.; Krauss, E.; Krauss, O.; Crayton, J.; James, D.; Krauss, C.; Mitchell, C.; Colgan, M.; Grogan, B.; Christofferson, J.

2005-12-01

323

Transparent Ceramic for Lightweight Armours.  

National Technical Information Service (NTIS)

Today, there is a growing need of light transparent armor concepts against the AP 12.7 mm projectile which can fulfill the mass and/or thickness specifications of helicopters or light armored vehicle programs. A new transparent ceramic material has been d...

C. E. Cottenot

1995-01-01

324

Transparency in Cooperative Online Education  

ERIC Educational Resources Information Center

|The purpose of this article is to discuss the following question: What is the potential of social networking within cooperative online education? Social networking does not necessarily involve communication, dialogue, or collaboration. Instead, the authors argue that "transparency" is a unique feature of social networking services. Transparency…

Dalsgaard, Christian; Paulsen, Morten Flate

2009-01-01

325

Multi-layer electrode for high contrast electrochromic devices  

SciTech Connect

An electrochromic device includes a first substrate spaced from a second substrate. A first transparent conductive electrode is formed over at least a portion of the first substrate. A polymeric anode is formed over at least a portion of the first conductive electrode. A second transparent conductive electrode is formed over at least a portion of the second substrate. In one aspect of the invention, a multi-layer polymeric cathode is formed over at least a portion of the second conductive electrode. In one non-limiting embodiment, the multi-layer cathode includes a first cathodically coloring polymer formed over at least a portion of the second conductive electrode and a second cathodically coloring polymer formed over at least a portion of the first cathodically coloring polymer. An ionic liquid is positioned between the anode and the cathode.

Schwendeman, Irina G. (Wexford, PA); Finley, James J. (Pittsburgh, PA); Polcyn, Adam D. (Pittsburgh, PA); Boykin, Cheri M. (Wexford, PA)

2011-11-01

326

Multiple channel programmable coincidence counter  

DOEpatents

A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the serializer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

Arnone, G.J.

1989-02-27

327

Transparent conducting coatings on glass tubes  

NASA Astrophysics Data System (ADS)

The conventional dip coating techinques, as it is used for flat surfaces, cannot be applied to deposit homogeneous coatings in optical quality inside tubes. The resulting coatings exhibit large variations in thickness and roughness over the length of the tube and show a morphology with a network of cracks. The main reason for these problems seem to be a delayed and restricted solvent evaporation due to the impediment of a laminar flow and the progressive saturation of the atmosphere in the tube. A modified dip coating technique was therefore developed to allow forced flow conditions inside the tubes by an additional exhausting tube. By means of this modification transparent conducting coatings of sol-gel SnO2:Sb (antimony-doped tin oxide - ATO) could be deposited on both sides of borosilicate glass tubes (300 mm, inner diamters down to 11 mm) with excellent thickness uniformity and low roughness (Ra? 1nm). After a heat treatment at temperatures up to 500°C, the prepared ATO coatings are mechanically stable and highly transparent (>85% transmission) with a sheet resistance down to 10 k?. The coatings can be used as electrodes for electronic devices and electrical heaters or to give antistatic properties to the substrate.

Puetz, Joerg; Chalvet, F. N.; Aegerter, Michel A.

2002-09-01

328

Highly transparent nonvolatile resistive memory devices from silicon oxide and graphene  

NASA Astrophysics Data System (ADS)

Transparent electronic memory would be useful in integrated transparent electronics. However, achieving such transparency produces limits in material composition, and hence, hinders processing and device performance. Here we present a route to fabricate highly transparent memory using SiOx as the active material and indium tin oxide or graphene as the electrodes. The two-terminal, nonvolatile resistive memory can also be configured in crossbar arrays on glass or flexible transparent platforms. The filamentary conduction in silicon channels generated in situ in the SiOx maintains the current level as the device size decreases, underscoring their potential for high-density memory applications, and as they are two-terminal based, transitions to three-dimensional memory packages are conceivable. As glass is becoming one of the mainstays of building construction materials, and conductive displays are essential in modern handheld devices, to have increased functionality in form-fitting packages is advantageous.

Yao, Jun; Lin, Jian; Dai, Yanhua; Ruan, Gedeng; Yan, Zheng; Li, Lei; Zhong, Lin; Natelson, Douglas; Tour, James M.

2012-10-01

329

Highly transparent nonvolatile resistive memory devices from silicon oxide and graphene.  

PubMed

Transparent electronic memory would be useful in integrated transparent electronics. However, achieving such transparency produces limits in material composition, and hence, hinders processing and device performance. Here we present a route to fabricate highly transparent memory using SiO(x) as the active material and indium tin oxide or graphene as the electrodes. The two-terminal, nonvolatile resistive memory can also be configured in crossbar arrays on glass or flexible transparent platforms. The filamentary conduction in silicon channels generated in situ in the SiO(x) maintains the current level as the device size decreases, underscoring their potential for high-density memory applications, and as they are two-terminal based, transitions to three-dimensional memory packages are conceivable. As glass is becoming one of the mainstays of building construction materials, and conductive displays are essential in modern handheld devices, to have increased functionality in form-fitting packages is advantageous. PMID:23033077

Yao, Jun; Lin, Jian; Dai, Yanhua; Ruan, Gedeng; Yan, Zheng; Li, Lei; Zhong, Lin; Natelson, Douglas; Tour, James M

2012-01-01

330

Pediatric Counter-Terrorism Measures  

Center for Drug Evaluation (CDER)

... Pediatric Counter-Terrorism Measures. ... Atropen (atropine autoinjector) FDA has approved new dosage forms of the Atropen for use in children and ... More results from www.fda.gov/drugs/emergencypreparedness/bioterrorismanddrugpreparedness

331

Cermet electrode  

DOEpatents

Disclosed is a cermet electrode consisting of metal particles of nickel, cobalt, iron, or alloys or mixtures thereof immobilized by zirconia stabilized in cubic form which contains discrete deposits of about 0.1 to about 5% by weight of praseodymium, dysprosium, terbium, or a mixture thereof. The solid oxide electrode can be made by covering a substrate with particles of nickel, cobalt, iron, or mixtures thereof, growing a stabilized zirconia solid oxide skeleton around the particles thereby immobilizing them, contacting the skeleton with a compound of praseodymium, dysprosium, terbium, or a mixture thereof, and heating the skeleton to a temperature of at least 500.degree. C. The electrode can also be made by preparing a slurry of nickel, cobalt, iron, or mixture and a compound of praseodymium, dysprosium, terbium, or a mixture thereof, depositing the slurry on a substrate, heating the slurry to dryness, and growing a stabilized zirconia skeleton around the metal particles.

Maskalick, Nicholas J. (Pittsburgh, PA)

1988-08-30

332

Magnetohydrodynamic electrode  

DOEpatents

An electrode capable of withstanding high temperatures and suitable for use as a current collector in the channel of a magnetohydrodynamic (MHD) generator consists of a sintered powdered metal base portion, the upper surface of the base being coated with a first layer of nickel aluminide, an intermediate layer of a mixture of nickel aluminide - refractory ceramic on the first layer and a third or outer layer of a refractory ceramic material on the intermediate layer. The sintered powdered metal base resists spalling by the ceramic coatings and permits greater electrode compliance to thermal shock. The density of the powdered metal base can be varied to allow optimization of the thermal conductivity of the electrode and prevent excess heat loss from the channel.

Marchant, David D. (Richland, WA); Killpatrick, Don H. (Orland Park, IL)

1978-01-01

333

Ruthenium-based, inert oxide electrodes for impregnating active materials in nickel plaques  

Microsoft Academic Search

Titanium electrodes coated with mixed ruthenium-iridium-titanium oxides are tested as inert counter electrodes for impregnating active materials in porous nickel plaques. The latter are to be used as the positive electrodes in nickel\\/cadmium cells. Weight losses and variations in bath voltage have been monitored while using these electrodes in the impregnation bath. A 2.85 Ah nickel\\/cadmium cell has been constructed

R. Manoharan; M. Uma

1997-01-01

334

Programmable spark counter of tracks  

Microsoft Academic Search

For the purpose, a new set—the programmable all-automatic spark counter AIST-4—has been developed and manufactured. Compared to our previous automated spark counter ISTRA, which was operated by the integrated fixed program, the new set is operated completely by a personal computer. The mechanism for pressing and pulling the aluminized foil is put into action by a step motor operated by

A. E. Denisov; V. A. Nikolaev; I. B. Vorobjev

2005-01-01

335

Two-Color-Counter Toss  

NSDL National Science Digital Library

In this probability lesson plan students explore the concept of probability and learn to use the language of probability to describe outcomes. Students conduct an experiment with a two color counter, making prediction ahead of time, collecting data as the experiment is conducted, and then reporting their results. A similar experiment is then conducted with two two-color counters. A student recording sheet and a worksheet on probability statements are included in PDF format.

2011-01-01

336

Transparent ceramics for sensor applications  

NASA Astrophysics Data System (ADS)

Transparent ceramics are finding applications in demanding optical applications were traditional mineral salts and amorphous materials are limited and single crystals are not practical. Polycrystalline ceramics offer a unique combination of mechanical, electrical and optical properties that allow window and dome applications and possibilities that were previously not possible. Transparent ceramics are being developed for use in a number of applications with each material possessing a distinctive set of properties that address a particular application. The current status of CeraNova's fine grain transparent ceramic programs for dome and window applications will be presented with emphasis on their exceptional material properties for specific applications.

Parish, Mark V.; Pascucci, Marina R.; Corbin, Normand; Puputti, Brenda

2013-06-01

337

All-solution-processed transparent thin film transistor and its application to liquid crystals driving.  

PubMed

All-solution-processed transparent thin film transistors (TTFTs) are demonstrated with silver grid source/drain electrodes, which are fabricated by printing and subsequent silver nanoparticles solution coating, which allows continuous processing without using high vacuum systems. The silver grid electrode shows a reasonable transmittance in visible range, moderate electrical conductance and mechanical strength. The TTFTs are employed to drive liquid crystal cells and demonstrate a successful switching operation. PMID:23606454

Lee, Kwang-Ho; Kim, Sang-Mook; Jeong, Huisu; Pak, Yusin; Song, Hui; Park, Jeongpil; Lim, Keon-Hee; Kim, Jae-Hoon; Kim, Youn Sang; Ko, Heung Cho; Kwon, Il Keun; Jung, Gun-Young

2013-04-22

338

Development Gateway: Public Sector Transparency  

NSDL National Science Digital Library

This particular site casts an eye on the question of transparency in governmental transactions through interviews with leaders from a broad range of sectors, along with allowing space for individual feedback. The "Points of View" section is a good place to start, as it includes commentary from government officials from Bolivia, Guatemala, and Tanzania about the question of public sector transparency. Other sections on the site address such thorny questions as "What tools help sustain public sector transparency?" and "What practices promote public-private partnerships?" Those visual learners coming to visit the site may appreciate the gallery of charts that offer indicators of levels of governance and transparency for more than 209 countries.

339

Transparent Armor Cost Benefit Study.  

National Technical Information Service (NTIS)

BASIC RESEARCH EFFORT: Goal is to develop nano-structured ceramic bodies with a combination of high optical transmission and exceptional mechanical properties and capable of effective performance in an outstanding transparent armor system.

D. Holm L. P. Franks R. Barnak

2008-01-01

340

Transparent Materials for Aerospace Enclosures,  

National Technical Information Service (NTIS)

The purpose of this report is to make available the technical papers presented at the recent Eighth Conference on 'Transparent Materials for Aerospace Enclosures'. This conference was held for the exchange of knowledge on new developments and design conce...

R. E. Wittman

1965-01-01

341

Transparent Ferroelectric Glass-Ceramics  

Microsoft Academic Search

In recent years, there has been a resurgence of interest in transparent ferroelectric glass-ceramics (TFGCs), which are a special class of glass-ceramic composites that combine the low cost of fabrication and forming of transparent glass with the superior nonlinear optical and electro-optical properties of ferroelectric crystals. In this paper, we present a review of the current status, focusing on the

H. JAIN

2004-01-01

342

Lines that induce phenomenal transparency.  

PubMed

Three neighbouring opaque surfaces may appear split into two layers, one transparent and one opaque beneath, if an outline contour is drawn that encompasses two of them. The phenomenon was originally observed by Kanizsa [1955 Rivista di Psicologia 69 3-19; 1979 Organization in Vision: Essays on Gestalt Psychology (New York: Praeger)], for the case where an outline contour is drawn to encompass one of the two parts of a bicoloured figure and a portion of a background of lightest (or darkest) luminance. Preliminary observations revealed that the outline contour yields different effects: in addition to the stratification into layers described by Kanizsa, a second split, opposite in depth order, may occur when the outline contour is close in luminance to one of the three surfaces. An initial experiment was designed to investigate what conditions give rise to the two phenomenal transparencies: this led to the conclusion that an outline contour superimposed on an opaque surface causes this surface to emerge as a transparent layer when the luminances of the contour and the surface differ, in absolute value, by no more than 13.2 cd m(-2). We have named this phenomenon 'transparency of the intercepted surface', to distinguish it from the phenomenal transparency arising when the contour and surface are very different in luminance. When such a difference exists, the contour acts as a factor of surface definition and grouping: the portion of the homogeneous surface it bounds emerges as a fourth surface and groups with a nearby surface if there is one close in luminance. The transparency phenomena ('transparency of the contoured surface') perceived in this context conform to the constraints of Metelli's model, as demonstrated by a second experiment, designed to gather 'opacity' ratings of stimuli. The observer judgments conformed to the values predicted by Metelli's formula for perceived degree of transparency, alpha. The role of the outline contour in conveying figural and intensity information is discussed. PMID:15943049

Grieco, Alba; Roncato, Sergio

2005-01-01

343

Transparent Conductors: Understanding and Optimization  

Microsoft Academic Search

The unique combination of two mutually exclusive properties -- optical transparency and electrical conductivity -- is known to be a prerogative of only a few oxides of post-transition metals, namely, In2O3, ZnO, CdO and SnO2. Advances in theoretical understanding of the underlying physical phenomena in conventional transparent conducting oxides (TCOs) and rapid development of the technologies for which TCO is

Julia Medvedeva

2011-01-01

344

The suppression of destructive sparks in parallel plate proportional counters  

SciTech Connect

The authors find that high energy background events produce localised sparks in parallel plate counters when operated in the proportional mode. These sparks increase dead-time and lead to degradation ranging from electrode damage to spurious pulsing and continuous breakdown. The problem is particularly serious in low energy photon detectors for X-ray astronomy which are required to have lifetimes of several years in the high radiation environment of space. For the parallel plate imaging detector developed for the European X-ray Observatory Satellite (EXOSAT) they investigate quantitatively the spark thresholds, spark rates and degradation processes. They discuss the spark mechanism, pointing out differences from the situation in spark chambers and counters. They show that the time profile of the sparks allows them to devise a spark suppression system which reduces the degradation rate by a factor of ''200.

Cockshott, R.A.; Mason, I.M.

1984-02-01

345

Plasma electrode pockels cell for ICF lasers  

SciTech Connect

In a plasma-electrode Pockels cell (PEPC), plasma discharges serve as transparent electrodes on each side of, an electrooptic crystal such as KDP. These plasmas facilitate rapid and uniform charging and discharging of the crystal. The authors describe PEPC technology deployed on Beamlet and envisioned for the National Ignition Facility. Performance on Beamlet is discussed in detail. They also discuss models which have shed light on PEPC operation. These models describe both the high-voltage sheath that forms near the crystal surface and the characteristics of the bulk plasma column.

Rhodes, M.A.; Boley, C.D.; Tarditi, A.G.; Bauer, B.S.

1995-07-07

346

Transparency at the level of safeguards implementation  

SciTech Connect

Safeguards approaches that include higher degrees of transparency at the level of facilities and at the level of the state also need a higher degree of transparency at the level of IAEA safeguards implementation. Here the author gives a brief discussion of: (1) confidentiality or transparency in the present approach; and (2) transparency in the alternative safeguards approach.

Petit, A.

1994-07-01

347

Nanostructured Solid Oxide Fuel Cell Electrodes  

SciTech Connect

The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

Sholklapper, Tal Zvi

2007-12-15

348

Photoinduced transparency in polypyrrole films  

NASA Astrophysics Data System (ADS)

For the first time we have discovered drastic photoinduced effects in the transparency for the pyrrole films. Photoinduced investigations of transparency were performed for the polypyrroles with different number of the pyrrole rings. We have established a considerable increase of the transparency from 70-75% up to 82-84% for the wavelengths of the probing lasers operating within the 530-1040 nm spectral range. The photoexcitation was performed by nanosecond pulsed polarized Nd-YAG laser generating at 1.34 ?m. The phototransparent changes are completely reversible and disappear after switching off the laser treatment. The typical relaxation time for the photoinduced transparency is equal to about 10-20 ?s and the changes of the transparency are strictly related with the values of state dipole moments of the polypyrroles. As a possible mechanism for explanation of the observed dependences one can consider existence of the charged trapping levels intra the forbidden energy gaps which effectively interact with the electric strength of the external polarized optical field and state dipole moments of the particular polymers.

Fuks-Janczarek, I.; Miedzi?ski, R.; Kityk, I. V.; Gondek, E.; Sanetra, J.

2007-09-01

349

Technological challenges in counter bioterrorism  

Microsoft Academic Search

In the current environment of potential threats of global bioterrorism, research and development efforts are being directed on several fronts for countering bioterrorism activities. These include both basic science initiatives and applied engineering innovations. In the context of science and technology challenges, some of the major issues to be addressed, include 1) understanding the 'make-up' of the biological agents used

Swamy Laxminarayan; B. Hudnall Stamm

2003-01-01

350

Countering Anonymity through Small Schools.  

ERIC Educational Resources Information Center

Chicago educators are countering anonymity with smaller schools that have been restructured and "recultured" into small learning communities stressing personalized instruction, high student visibility, and teacher collaboration. Since the mid-1990s, 130 small-design elementary and secondary schools serving 42,000 students have been established.…

Klonsky, Susan; Klonsky, Michael

1999-01-01

351

High resolution time interval counter  

DOEpatents

A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

Condreva, Kenneth J. (Livermore, CA)

1994-01-01

352

Synchronized Current Oscillations of Formic Acid Electro-oxidation in a Microchip-based Dual-Electrode Flow Cell  

PubMed Central

We investigate the oscillatory electro-oxidation of formic acid on platinum in a microchip-based dual-electrode cell with microfluidic flow control. The main dynamical features of current oscillations on single Pt electrode that had been observed in macro-cells are reproduced in the microfabricated electrochemical cell. In dual-electrode configuration nearly in-phase synchronized current oscillations occur when the reference/counter electrodes are placed far away from the microelectrodes. The synchronization disappears with close reference/counter electrode placements. We show that the cause for synchronization is weak albeit important, bidirectional electrical coupling between the electrodes; therefore the unidirectional mass transfer interactions are negligible. The experimental design enables the investigation of the dynamical behavior in micro-electrode arrays with well-defined control of flow of the electrolyte in a manner where the size and spacing of the electrodes can be easily varied.

Kiss, Istvan Z.; Munjal, Neil; Martin, R. Scott

2009-01-01

353

Compliant composite electrodes and large strain bistable actuation  

NASA Astrophysics Data System (ADS)

Dielectric elastomer actuators (DEA) and bistable electroactive polymers (BSEP) both require compliant electrodes with rubbery elasticity and high conductivity at large strains. Stretchable opto-electronic devices additionally require the compliant electrodes to be optically transparent. Many candidate materials have been investigated. We report a new approach to mechanically robust, stretchable compliant electrodes. A facile in-situ composite synthesis and transfer technique is employed, and the resulting composite electrodes retain the high surface conductivity of the original conductive network formed by nanowires or nanotubes, while exhibiting the mechanical flexibility of the matrix polymer. The composite electrodes have high transparency and low surface roughness useful for the fabrication of polymer thinfilm electronic devices. The new electrodes are suitable for high-strain actuation, as a complaint resistive heating element to administer the temperature of shape memory polymers, and as the charge injection electrodes for flexible/stretchable polymer light emitting diodes. Bistable electroactive polymers employing the composite electrodes can be actuated to large strains via heating-actuation-cooling cycles.

Yun, Sungryul; Yu, Zhibin; Niu, Xiaofan; Hu, Weili; Li, Lu; Brochu, Paul; Pei, Qibing

2012-03-01

354

Transparent ceramics for spacecraft windows  

NASA Astrophysics Data System (ADS)

The mechanical properties of several transparent ceramics were investigated to determine if their use might lighten next generation spacecraft windows. The measured fracture toughness and slow crack growth parameters were used as inputs to functions describing the required mass for a desired window life. Transparent magnesium aluminate (spinel, MgAlO4) and AlON exhibit superior slow crack resistance relative to fused silica, which is the historical material of choice. For spinel, slow crack growth, strength and fracture toughness are significantly influenced by the grain size, and alumina rich phases and porosity at the grain boundaries lead to intergranular fracture in coarse grain spinel. The results imply that transparent ceramics can lighten window panes from a slow crack growth perspective.

Salem, Jonathan A.

2013-06-01

355

Electrochemical synthesis of adherent polypyrrole films on zinc electrodes in acidic and neutral organic media  

Microsoft Academic Search

The electrodeposition of polypyrrole on zinc electrodes has been performed by anodic oxidation of pyrrole in acetonitrile, nitrobenzene and propylene carbonate media in the presence of para-toluene sulfonate counter-ions. When the zinc electrode has preferably undergone a chemical treatment by aqueous sodium sulfide solution, homogeneous and adherent PPy films are obtained. While, no PPy film grows (in the case of

M Bazzaoui; E. A Bazzaoui; L Martins; J. I Martins

2002-01-01

356

Ultra-thin films on transparent conductor oxides for the development of spectro-electrochemical transducers  

NASA Astrophysics Data System (ADS)

Transparent C, Au and Pt films with thickness in the 5-10 nm range have been deposited by a DC magnetron sputtering system on commercial ITO (indium tin oxide) coated glass substrate for evaluation as electrode of spectro-electrochemical transducer. The transmission, over the investigated spectral range, is superior to 55% with the best transmission values obtained for C films (higher than 80%). The deposited films have been characterized by AFM, XPS and electrochemical methods. Results showed a low roughness, improved in comparison with uncoated electrodes. Electrochemical properties of the Au and Pt films evidenced a metallic behavior, which allowed qualifying them as conductive optically transparent electrodes for spectro-electrochemical devices.

Grigore, E.; Delacôte, C.; Thobie-Gautier, C.; Boujtita, M.; Tessier, P. Y.

2013-07-01

357

A transparent and stretchable graphene-based actuator for tactile display  

NASA Astrophysics Data System (ADS)

A tactile display is an important tool to help humans interact with machines by using touch. In this paper, we present a transparent and stretchable graphene-based actuator for advanced tactile displays. The proposed actuator is composed of transparent and compliant graphene electrodes and a dielectric elastomer substrate. Since the electrode is coated onto the appointed region of the substrate layer by layer, only the area of the dielectric elastomer substrate with electrodes bumps up in response to the input voltage, which consequently produces actuation. The actuator is proven to be operable while preserving its electrical and mechanical properties even under 25% stretching. Also, the simple fabrication of the proposed actuator is cost-effective and can easily be extended to multiple arrays. The actuator is expected to be applicable to various applications including tactile displays, vari-focal lenses etc.

Kim, Uikyum; Kang, Junmo; Lee, Choonghan; Kwon, Hyeok Yong; Hwang, Soonhwi; Moon, Hyungpil; Koo, Ja Choon; Nam, Jae-Do; Hong, Byung Hee; Choi, Jae-Boong; Ryeol Choi, Hyouk

2013-04-01

358

Specific problems using electronic particle counters  

Microsoft Academic Search

Some specific problems of electronic particle counters (Coulter Counter, Elzone) are discussed. Conductivity of the medium does not influence the size response of the instrument, but might change the size of the particles through osmotic stress.

Kees Kersting

1985-01-01

359

Basic Research Needs for Countering Terrorism  

SciTech Connect

To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism

Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; David Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

2002-03-01

360

Digital Displays for CAMAC Counter Systems.  

National Technical Information Service (NTIS)

Devices for digital displaying, intended for CAMAC counter systems and able to operate in non-computer autonomous mode, are described. Two kinds of displays are considered: counters with individual nixie digit displays and common displays for whole crate....

N. I. Zhuravlev Li Zu Ehk Nguen Man' Shat V. T. Sidorov A. N. Sinaev

1976-01-01

361

Basic Research Needs for Countering Terrorism  

Microsoft Academic Search

To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism

W. Stevens; T. Michalske; J. Trewhella; L. Makowski; B. Swanson; S. Colson; T. Hazen; F. Roberto; D. David Franz; G. Resnick; S. Jacobson; J. Valdez; P. Gourley; M. Tadros; M. Sigman; M. Sailor; M. Ramsey; B. Smith; K. Shea; J. Hrbek; P. Rodacy; D. Tevault; N. Edelstein; J. Beitz; C. Burns; G. Choppin; S. Clark; M. Dietz; R. Rogers; S. Traina; D. Baldwin; M. Thurnauer; G. Hall; L. Newman; D. Miller; H. Kung; D. Parkin; D. Shuh; H. Shaw; L. Terminello; D. Meisel; D. Blake; M. Buchanan; J. Roberto; R. Carling; G. Samara; D. Sasaki; P. Pianetta; B. Faison; D. Thomassen; T. Fryberger; G. Kiernan; M. Kreisler; L. Morgan; J. Hicks; J. Dehmer; L. Kerr; J. Mays

2002-01-01

362

Modiolus-hugging intracochlear electrode array with shape memory alloy.  

PubMed

In the cochlear implant system, the distance between spiral ganglia and the electrodes within the volume of the scala tympani cavity significantly affects the efficiency of the electrical stimulation in terms of the threshold current level and spatial selectivity. Because the spiral ganglia are situated inside the modiolus, the central axis of the cochlea, it is desirable that the electrode array hugs the modiolus to minimize the distance between the electrodes and the ganglia. In the present study, we propose a shape-memory-alloy-(SMA-) embedded intracochlear electrode which gives a straight electrode a curved modiolus-hugging shape using the restoration force of the SMA as triggered by resistive heating after insertion into the cochlea. An eight-channel ball-type electrode array is fabricated with an embedded titanium-nickel SMA backbone wire. It is demonstrated that the electrode array changes its shape in a transparent plastic human cochlear model. To verify the safe insertion of the electrode array into the human cochlea, the contact pressures during insertion at the electrode tip and the contact pressures over the electrode length after insertion were calculated using a 3D finite element analysis. The results indicate that the SMA-embedded electrode is functionally and mechanically feasible for clinical applications. PMID:23762181

Min, Kyou Sik; Jun, Sang Beom; Lim, Yoon Seob; Park, Se-Ik; Kim, Sung June

2013-05-09

363

Modiolus-Hugging Intracochlear Electrode Array with Shape Memory Alloy  

PubMed Central

In the cochlear implant system, the distance between spiral ganglia and the electrodes within the volume of the scala tympani cavity significantly affects the efficiency of the electrical stimulation in terms of the threshold current level and spatial selectivity. Because the spiral ganglia are situated inside the modiolus, the central axis of the cochlea, it is desirable that the electrode array hugs the modiolus to minimize the distance between the electrodes and the ganglia. In the present study, we propose a shape-memory-alloy-(SMA-) embedded intracochlear electrode which gives a straight electrode a curved modiolus-hugging shape using the restoration force of the SMA as triggered by resistive heating after insertion into the cochlea. An eight-channel ball-type electrode array is fabricated with an embedded titanium-nickel SMA backbone wire. It is demonstrated that the electrode array changes its shape in a transparent plastic human cochlear model. To verify the safe insertion of the electrode array into the human cochlea, the contact pressures during insertion at the electrode tip and the contact pressures over the electrode length after insertion were calculated using a 3D finite element analysis. The results indicate that the SMA-embedded electrode is functionally and mechanically feasible for clinical applications.

Min, Kyou Sik; Lim, Yoon Seob; Park, Se-Ik; Kim, Sung June

2013-01-01

364

Enhancing light extraction in top-emitting organic light-emitting devices using molded transparent polymer microlens arrays.  

PubMed

The light extraction efficiency in organic light-emitting devices (OLEDs) is enhanced by up to 2.6 times when a close-packed, hemispherical transparent polymer microlens array (MLA) is molded on the light-emitting surface of a top-emitting device. The microlens array helps to extract the waveguided optical emission in the organic layers and the transparent top electrode, and can be manufactured in large area with low cost. PMID:22678825

Wrzesniewski, Edward; Eom, Sang-Hyun; Cao, Weiran; Hammond, William T; Lee, Sangjun; Douglas, Elliot P; Xue, Jiangeng

2012-06-08

365

Calibration of proportional counters in microdosimetry  

Microsoft Academic Search

Many microdosimetric spectra for low LET as well as high LET radiations are measured using commercially available (similar to EG and G) Rossi proportional counters. The corrections to be applied to data when calibration of the counter is made using one type of radiation, and then the counter is used in a different radiation field. The principal correction factor is

M. N. Varma

1982-01-01

366

Amplifier design considerations for blood cell counter sampling probes.  

PubMed

Blood cell counters that operate on the Coulter principle of an electrical resistance change when a cell passes through a small sampling orifice are especially sensitive to electrical noise. The sampling probe is immersed in an electrolyte (isotonic diluent for blood cells), which in itself presents an electrochemically noisy environment. The probe, owing to its large size, acts as an antenna for environmental electrical noise up to 60 Hz. Additionally, the basic Coulter method for cell counting requires a dc potential across the sampling orifice electrodes contained within the probe. This potential produces electrolysis of the diluent and generation of gas bubbles at the electrode surfaces. Sampling (counting) time must be short (less than 30 seconds) to avoid sample heating and an intolerably high noise level as a consequence of ionic motion and gas bubble generation. The resistance change that takes place when a cell passes through the sampling orifice is only a small fraction of a percent, thus noise is a serious problem. Electric noise produces false counts and general degradation of counting function. This paper presents a discussion of a currently used method for signal acquisition and some of the problems encountered in the clinical laboratory. A novel alternative design has been implemented using integrated circuit components, which eliminates many of the problems associated with the use of small bench-type counters. Design philosophy is discussed in detail including presentation of the final circuitry developed. Performance characteristics of the signal acquisition circuitry are presented.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3943959

Ferris, C D; Veal, B L

1986-01-01

367

Transparent Ceramics: Magnesium Aluminate Spinel.  

National Technical Information Service (NTIS)

There is a need for high-strength, rugged materials that transmit in the visible and mid-infrared (0.4 to 5 microns) wavelength region. These materials are needed for applications requiring transparent armor, including next-generation high-speed missiles ...

G. R. Villalobos I. D. Aggarwal J. S. Sanghera

2005-01-01

368

Transparent ceramic lamp envelope materials  

NASA Astrophysics Data System (ADS)

Transparent ceramic materials with optical qualities comparable to single crystals of similar compositions have been developed in recent years, as a result of the improved understanding of powder-processing-fabrication- sintering-property inter-relationships. These high-temperature materials with a range of thermal and mechanical properties are candidate envelopes for focused-beam, short-arc lamps containing various fills operating at temperatures higher than quartz. This paper reviews the composition, structure and properties of transparent ceramic lamp envelope materials including sapphire, small-grained polycrystalline alumina, aluminium oxynitride, yttrium aluminate garnet, magnesium aluminate spinel and yttria-lanthana. A satisfactory thermal shock resistance is required for the ceramic tube to withstand the rapid heating and cooling cycles encountered in lamps. Thermophysical properties, along with the geometry, size and thickness of a transparent ceramic tube, are important parameters in the assessment of its resistance to fracture arising from thermal stresses in lamps during service. The corrosive nature of lamp-fill liquid and vapour at high temperatures requires that all lamp components be carefully chosen to meet the target life. The wide range of new transparent ceramics represents flexibility in pushing the limit of envelope materials for improved beamer lamps.

Wei, G. C.

2005-09-01

369

Could Transparency Bring Economic Diversity?  

ERIC Educational Resources Information Center

The Spellings Commission report calls for greater access to higher education for low- and moderate-income students, greater transparency in the way higher education works and greater accountability for producing results. These recommendations are all significant in their own right, but the three concepts also converge to provide powerful support…

Kahlenberg, Richard D.

2007-01-01

370

First townsend coefficient of organic vapour in avalanche counters  

NASA Astrophysics Data System (ADS)

A new concept is presented in the paper for implementing the proven method of determining the first Townsend coefficient (?) of gases using an avalanche counter. The A and B gas constants, interrelated by the expression ?/p = A exp[-B/(K/p)], are analyzed. Parallel-plate avalanche counters (PPAC) with an electrode spacing d from 0.1 to 0.4 cm have been employed for the investigation, arranged to register low-energy alpha particles at n-heptane vapour pressures of p >= 5 Torr. An in-depth discussion is given, covering the veracity and the behaviour vs K/p, of the n-heptane A and B constants determined at reduced electric-field intensity values ranging from 173.5 to 940 V/cm Torr; the constants have been found to depend upon d. The results of the investigation are compared to available data of the ? coefficient of organic vapours used in avalanche counters. The PPAC method of determining ? reveals some imperfections at very low values of the pd product.

Sernicki, Jan

1990-03-01

371

UN Action To Counter Terrorism  

NSDL National Science Digital Library

The United Nations has been concerned about the growing threat of terrorism for decades, and in 2006, their member states adopted a comprehensive global strategy to counter terrorism. Visitors with an interest in their strategy will want to visit the site to read about the strategy and to also learn about some of their related activities. After reading a brief introduction about the overall strategy, visitors can read the complete United Nations Counter-Terrorism Handbook and also view the latest news updates related to their efforts to combat terrorism around the globe. Along the left-hand side of the homepage, visitors can also look over sections that include "Strategic Framework", "International Instruments", and "Human Rights". Visitors should also be aware that these materials are also available in Arabic, French, Russian, Spanish, and Chinese.

372

Highly clear conductive polymer electrode films hybridized with gold nanoparticles  

NASA Astrophysics Data System (ADS)

Improved conductive poly(3,4-ethylenedioxy thiophene) (PEDOT) electrode films were made through hybridization with charged gold nanoparticles. The conductivity of these hybrid films increased more than seven times than the value for the PEDOT alone. The optimized films show a sheet resistance value down to 85 ohm.sq-1 at 85% transparency when PEDOT was hybridized with gold particles of 12 nm diameter, and the organic light-emitting diode devices deposited on these electrodes show a performance equivalent to that of devices based on a conventional indium tin oxide electrode.

Kim, Jin-Yeol; Hwang, Che-Ryong; Jo, Sang-Hyun; Jung, Woo-Gwang

2011-12-01

373

Negative Electrode Composition.  

National Technical Information Service (NTIS)

A secondary electrochemical cell and a negative electrode composition for use therewith comprising a positive electrode containing an active material of a chalcogen or a transition metal chalcogenide, a negative electrode containing a lithium-aluminum all...

T. D. Kaun A. A. Chilenskas

1980-01-01

374

A miniature fast fission counter  

Microsoft Academic Search

A small, 1\\/4 inch diameter by 1\\/2 inch in length, fast neutron fission ; counter probe employing highly depleted uranium as the fission material is ; developed. The isotopic analysis of the uranium, obtained by the 3-stage mass ; spectrometer is as follows: U²³⁸ (essentially 100%) U²³⁶ (0.03 ; plus or minus 0.02 ppm), U²³⁵ (0.90 plus or minus 0.20

G. Hickman

1961-01-01

375

Over-the-Counter Markets  

Microsoft Academic Search

We study how intermediation and asset prices in over-the-counter markets are affected by illiquidity associated with search and bargaining. We compute explicitly the prices at which investors trade with each other as well as marketmakers' bid and ask prices in a dynamic model with strategic agents. Bid-ask spreads are lower if investors can more easily find other investors, or have

Darrell Duffie; Nicolae Garleanu; Lasse Heje Pedersen

2004-01-01

376

Science role in countering terrorism  

NASA Astrophysics Data System (ADS)

Geoscience expertise figures as a component of a new report on harnessing the U.S. science and technology community in the fight against terrorism.The National Research Council report, "Making the Nation Safer: The Role of Science and Technology in Countering Terrorism," proposes research agendas in a number of areas perceived to be vulnerable to terrorism. These areas include nuclear and radiological threats, toxic chemicals and explosive materials, information technology, energy systems, and cities and fixed infrastructure.

Showstack, Randy

377

Science role in countering terrorism  

NASA Astrophysics Data System (ADS)

Geoscience expertise figures as a component of a new report on harnessing the U.S. science and technology community in the fight against terrorism.The National Research Council report, “Making the Nation Safer: The Role of Science and Technology in Countering Terrorism,” proposes research agendas in a number of areas perceived to be vulnerable to terrorism. These areas include nuclear and radiological threats, toxic chemicals and explosive materials, information technology, energy systems, and cities and fixed infrastructure.

Showstack, Randy

378

Boron-10 Lined Proportional Counter Wall Effects  

SciTech Connect

The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube based system in the configuration of a coincidence counter. This report provides information about how variations in proportional counter radius and gas pressure in a typical coincident counter design might affect the observed signal from boron-lined tubes. A discussion comparing tubes to parallel plate counters is also included.

Siciliano, Edward R.; Kouzes, Richard T.

2012-05-01

379

Design, construction and mechanical optimisation process of electrode with radial current flow in the scala tympani.  

PubMed

A 48 contact cochlear implant electrode has been constructed for electrical stimulation of the auditory nerve. The stimulating contacts of this electrode are organised in two layers: 31 contacts on the upper surface directed towards the habenula perforata and 17 contacts connected together as one longitudinal contact on the underside. The design of the electrode carrier aims to make radial current flow possible in the cochlea. The mechanical structure of the newly designed electrode was optimised to obtain maximal insertion depth. Electrode insertion tests were performed in a transparent acrylic model of the human cochlea. PMID:12948557

Deman, P R; Kaiser, T M; Dirckx, J J; Offeciers, F E; Peeters, S A

2003-09-30

380

Indium--Tin Oxide/Al Reflective Electrodes for Ultraviolet Light-Emitting Diodes  

NASA Astrophysics Data System (ADS)

We investigated indium--tin oxide (ITO)/Al reflective electrodes for improving the light extraction efficiency of UV light-emitting diodes (LEDs). The ITO layer showed high transparency in the UV region upon optimization of the thickness and annealing temperature. As a result, the ITO/Al electrode exhibited both high reflectivity in the UV region and good contact characteristics simultaneously. Using this electrode, we succeeded in improving the light output power of a 350 nm UV-A LED.

Takehara, Kosuke; Takeda, Kenichiro; Ito, Shun; Aoshima, Hiroki; Iwaya, Motoaki; Takeuchi, Tetsuya; Kamiyama, Satoshi; Akasaki, Isamu; Amano, Hiroshi

2012-04-01

381

Extended Terminal Transparent Display Language (TTDL).  

National Technical Information Service (NTIS)

This documents the development of the Extended Terminal Transparent Display Language (TTDL). TTDL is a terminal handling system which stresses transparency between terminals. It was developed as part of the TOSS system. (Author)

C. Y. Bumgardner C. Krebs T. Northwood C. Weiskopf

1976-01-01

382

Novel Transparent PMMA Composites For Optical Tagging.  

National Technical Information Service (NTIS)

This report describes the success of a feasibility demonstration in making novel transparent poly(methyl methacrylate) PMMA composites with ultraviolet (UV)-dye-embedded electrospun fibers that have the ability to change color and transparency reversibly ...

A. J. Hsieh G. C. Rutledge J. H. Yu

2010-01-01

383

Transparent Conducting Thin Films for Spacecraft Applications.  

National Technical Information Service (NTIS)

Transparent conductive thin films are required for a variety of optoelectronic applications: automotive and aircraft windows, and solar cells for space applications. Transparent conductive coatings of indium-tin-oxide (ITO)-magnesium fluoride (MgF2) and a...

M. E. Perez-davis T. Malave-sanabria P. Hambourger S. K. Rutledge D. Roig

1994-01-01

384

Fracture properties and behavior of transparent ceramics  

NASA Astrophysics Data System (ADS)

For the past several decades, the Army has been interested in materials transparent to visible and infrared wavelengths for use in armor, IR windows and sensor windows. Future requirements for transparent armor are systems that can defeat greater threats without increased weight and thickness and minimal optical distortion. The Army Research Laboratory is developing transparent armor systems to increase the performance of new windows. Aluminum oxynitride spinel and single-crystal sapphire are two of the ceramic candidates for advanced transparent armor applications.

Patel, Parimal J.; Swab, Jeffrey J.; Gilde, Gary A.

2000-10-01

385

Transparent white organic light emitting diodes with improved cathode transparency  

Microsoft Academic Search

We have fabricated transparent white organic light emitting diode (WOLED) for lighting application based on a hybrid white OLED and a phosphorescence white OLED. For the hybrid WOLED, a blue fluorescence emitting layer (FLEML) and green and red phosphorescence emitting layers (PH-EMLs) have been used in the device structure of ITO\\/hole transporting layer (HTL)\\/PH-EMLs\\/interlayer\\/FL-EML\\/ETL\\/LiF\\/Al. The balanced emissions from the FLEML

Jeong-Ik Lee; Jonghee Lee; Joowon Lee; Jae-Heon Shin; Chi-Sun Hwang; Hye Yong Chu

2009-01-01

386

Fracture properties and behavior of transparent ceramics  

Microsoft Academic Search

For the past several decades, the Army has been interested in materials transparent to visible and infrared wavelengths for use in armor, IR windows and sensor windows. Future requirements for transparent armor are systems that can defeat greater threats without increased weight and thickness and minimal optical distortion. The Army Research Laboratory is developing transparent armor systems to increase the

Parimal J. Patel; Jeffrey J. Swab; Gary A. Gilde

2000-01-01

387

Promoting Improved Ballistic Resistance of Transparent Armor  

Microsoft Academic Search

Transparent armor is a material or system of materials designed to be optically transparent, yet protect from fragmentation or ballistic impacts. Although engineered to defeat specific threats, or a range of threats, there are general requirements common to all of these designs. The primary requirement for a transparent armor system is to not only defeat the designated threat but also

Andrew A Wereszczak; P Patel; D W Templeton

2011-01-01

388

Financial Reporting Transparency and Earnings Management  

Microsoft Academic Search

Prior research indicates that greater transparency in reporting formats facilitates the detection of earnings management. The current study hypothesizes and demonstrates that greater transparency in comprehensive income reporting also re- duces the likelihood that managers will engage in earnings management in the area of increased transparency. In our experiment, 62 financial executives and chief executive officers decide which available-for-sale security

James E. Hunton; Robert Libby; Cheri L. Mazza

2006-01-01

389

Parsimony & Transparency in Ubiquitous Interface Design  

Microsoft Academic Search

Minimalism in ubiquitous interface design allows computa- tional augmentations to seamlessly coexist with existing ar- tifacts and the constellations of task behaviors surrounding them. Specifically, parsimony and transparency contribute to improved learnability and user acceptance of novel interfaces. We present a design philosophy for ubiquitous computing cen- tered on parsimony and transparency. By transparently in- tegrating aspects of the digital

Christopher R. Wren; Carson J. Reynolds

2002-01-01

390

Transparent metals for ultrabroadband electromagnetic waves.  

PubMed

Making metals transparent, which could lead to fascinating applications, has long been pursued. Here we demonstrate that with narrow slit arrays metallic plates become transparent for extremely broad bandwidths; the high transmission efficiency is insensitive to the metal thickness. This work provides a guideline to develop novel devices, including transparent conducting panels, broadband metamaterials, and antireflective solar cells. PMID:22431279

Fan, Ren-Hao; Peng, Ru-Wen; Huang, Xian-Rong; Li, Jia; Liu, Yongmin; Hu, Qing; Wang, Mu; Zhang, Xiang

2012-03-19

391

True two-phase CCD image sensors employing a transparent gate  

NASA Astrophysics Data System (ADS)

This paper describes the performance of a family of full- frame sensor designed where a transparent electrode replaces one of the polysilicon gates. The sensors are all fabricated with a true two-phase buried channel CCD process that is optimized for operation in multi-pinned phase mode for low dark current. The true two-phase architecture provides many advantages such as progressive scan, square pixels, high charge capacity, and simplified drive requirements. The uncomplicated structure allows large area arrays to be fabricated with reasonable yield. Inclusion of a transparent gate increases the response by a factor of 10 at 400 nm and 50 percent at 600 nm.

Des Jardin, William; Kosman, Stephen L.

1999-04-01

392

Transparent ceramic lamp envelope materials  

Microsoft Academic Search

Transparent ceramic materials with optical qualities comparable to single crystals of similar compositions have been developed in recent years, as a result of the improved understanding of powder-processing-fabrication- sintering-property inter-relationships. These high-temperature materials with a range of thermal and mechanical properties are candidate envelopes for focused-beam, short-arc lamps containing various fills operating at temperatures higher than quartz. This paper reviews

G C Wei

2005-01-01

393

Transparent multiprocessing boosts MUC throughput  

SciTech Connect

Although multitasking and multiprocessing have become common features of microprocessor operating sytems, rarely can the software support multiple processors. One exception is the IMAX operating sytem, written in ADA and running on IAPX 432 general-purpose data processors. By keeping tasks independent of the processors which operate on them, IMAX makes multiprocessing transparent. The 432's multiprocessing architecture solves the problem of keeping task dispatching independent of processors. The system is described.

Kinder, D.

1982-04-15

394

Ion-Selective Electrodes.  

ERIC Educational Resources Information Center

|Literature on ion-selective electrodes (ISEs) is reviewed in seven sections: books, conferences, reviews; potentiometric membrane electrodes; glass and solid-state membrane electrodes; liquid and polymer membrane ISEs; coated wire electrodes, ion-selective field effect transistors, and microelectrodes; gas sensors and selective bioelectrode…

Arnold, Mark A.; Meyerhoff, Mark E.

1984-01-01

395

Rechargeable lithiated thin film intercalation electrode battery  

SciTech Connect

This patent describes a rechargeable lithium battery, it comprises: an electrode providing a source of lithium ions, an electrolyte, and a counter-electrode consisting essentially of a lithiated transition metal oxide intercalation compound selected from the class consisting of LiMn{sub 2}O{sub 4}, LiCoO{sub 2} and LiNiO{sub 2} characterized in that the counter-electrode consists essentially of a thin film of the intercalation compound prepared by situating a suitable coating substrate in an air-tight enclosure with a supply of the lithiated metal oxide; establishing within the enclosure a low pressure, carbon-free atmosphere; vaporizing at least a portion of the metal oxide; condensing the metal oxide vapor on a surface of the substrate in a coating having a thickness in the range of about 1 to 5 micrometers; and heating the coating within the atmosphere at a temperature and for a time sufficient to convert the coating to crystallites of the metal oxide having a grain size in the range of about 0.05 to 0.1 micrometer.

Shokoohi, F.K.; Tarascon, J.M.

1992-05-05

396

Performance of microstrip proportional counters for x-ray astronomy on spectrum-roentgen-gamma  

NASA Astrophysics Data System (ADS)

DSRI will provide a set of four imaging proportional counters for the Danish-Soviet x-ray telescopes XSPECT/SODART. The sensor principle is based on the novel micro-strip proportional counter (MSPC), where the strip electrodes are deposited by photolithography onto a rigid substrate. The MSPC offers many advantages: a uniform gas gain, an excellent energy resolution, the possibility to match the strip pitch to the desired positron resolution, a fast charge collection, and low operating voltages. However, a stable behavior of the MSPC requires a careful choice of both substrate and strip electrode material. The low energy detectors are equipped with polyimide windows of 0.5 micrometers thickness, providing a high quantum efficiency even at 200 eV with an energy resolution comparable to that of solid state detectors. The MSPC is capable of operating at high counting rates (10(superscript 5) ph s(superscript -1)) and the electronics are designed to match this capability.

Budtz-Joergensen, Carl C.; Bahnsen, Axel; Christensen, Finn E.; Madsen, M. M.; Olesen, C.; Schnopper, Herbert W.

1991-10-01

397

Variability of electrode positions using electrode caps.  

PubMed

We investigated the variability of electrode positions for a multi-channel, custom electrode cap placed onto participants' heads without taking scalp measurements. The electrode positions were digitized in a three-dimensional space for 10 young adult participants on three separate occasions. Positional variability was determined for 15 selected electrodes within the three-dimensional preauricular-nasion (PAN) coordinate system and from this system, angular coordinate variability was also determined. The standard deviations of the 15 selected electrodes ranged from 3.0 to 12.7 mm in the PAN system. These data resulted in a variability of 2.0 degrees to 10.4 degrees among the angular coordinates. The measurements indicated slightly greater variability of electrode positions compared to studies when electrodes were placed using scalp measurements. The implication of this study is that the use of electrode caps may not be appropriate when electroencephalographic (EEG) or evoked potential (EP) techniques depend on accurate electrode placement. Additionally, if a longitudinal study is performed, electrode locations should be checked to ensure that they conform with previous sessions. PMID:17929157

Atcherson, Samuel R; Gould, Herbert Jay; Pousson, Monique A; Prout, Tina M

2007-10-11

398

Application of microstrip proportional counters at the Danish Space Research Institute  

NASA Astrophysics Data System (ADS)

The low energy proportional counter LEPC (0.2-8 keV) and the high energy proportional counter HEPC (2-25 keV) for the Danish-Russian X-ray telescopes XSPECT/SODART are presently being tested at DSRI. The sensor principle of these detectors is based on the novel microstrip proportional counter (MSPC) where the strip electrodes are deposited by photolithography onto a rigid substrate. The MSPC offers many advantages: a uniform gas gain, excellent energy (~ 13% at 6 keV) and position-resolutions (<< 1 mm), a fast charge collection and a low operating voltage. The energy response, imaging and background rejection performance of LEPC (82 × 82 mm) and HEPC (Ø= 160 mm) will be discussed. The presentation will also include first results obtained with a high energy (~ 150 keV) MSPC which is planned as a candidate for the X-ray monitor for the International Gamma-Ray Astrophysical Laboratory (INTEGRAL).

Budtz-Jørgensen, C.; Bahnsen, A.; Møhl Madsen, M.; Olesen, C.; Jonasson, P.; Schnopper, H. W.

1994-09-01

399

High-Energy/Low-Energy Proportional Counter (HEPC/LEPC) detector systems on the SRG  

NASA Astrophysics Data System (ADS)

The low energy proportional counter LEPC (0.2 - 8 keV) and the high energy proportional counter HEPC (2 - 25 keV) for the Danish-Russian X-ray telescopes XSPECT/SODART are presently being tested at DSRI. The sensor principle of these detectors is based on the novel micro strip gas counter (MSGC) where the strip electrodes are deposited by photolithography onto a rigid substrate. The MSGC offers many advantages: A uniform gas gain, an excellent energy (approximately 13% at 6 keV) and position-resolutions (>> 1 mm), a fast charge collection and a low operating voltage. The energy response, imaging and background rejection performance of LEPC (82 X 82 mm) and HEPC ((sigma) equals 160 mm) will be discussed.

Budtz-Joergensen, Carl C.; Bahnsen, Axel; Madsen, M. M.; Olesen, C.; Jonasson, P.; Schnopper, Herbert W.

1994-11-01

400

Large scale, highly conductive and patterned transparent films of silver nanowires on arbitrary substrates and their application in touch screens  

Microsoft Academic Search

The application of silver nanowire films as transparent conductive electrodes has shown promising results recently. In this paper, we demonstrate the application of a simple spray coating technique to obtain large scale, highly uniform and conductive silver nanowire films on arbitrary substrates. We also integrated a polydimethylsiloxane (PDMS)-assisted contact transfer technique with spray coating, which allowed us to obtain large

Anuj R. Madaria; Akshay Kumar; Chongwu Zhou

2011-01-01

401

Fabrication and Optoelectronic Properties of a Transparent ZnO Homostructural Light-Emitting Diode  

Microsoft Academic Search

A transparent ZnO homostructural light-emitting diode (LED) with a structure of Au electrode\\/p(i)-ZnO film\\/n-ZnO single crystal\\/In electrode was fabricated using the technique of N2O plasma-enhanced pulsed laser reactive deposition. The contact between the p(i)-ZnO layer and n-ZnO wafer was found to exhibit nonlinear and rectifying current-voltage (I-V) characteristics. A current injection emission with bluish-white light was clearly observed at room

Xin-Li Guo; Jae-Hyoung Choi; Hitoshi Tabata; Tomoji Kawai

2001-01-01

402

Which Disposable Chest Electrode?  

PubMed Central

Chest electrodes are preferred to limb electrodes for cardiac monitoring, as limb movements are not restricted and produce less interference of the E.C.G. trace. Eight types of disposable chest electrodes were investigated to compare their performance, skin reactions, cost, ease of application, size, and skin–electrode impedance. Elema-Schonander electrodes were found to be the most efficient and the most expensive. In their application care was required to avoid severe skin reactions. Dracard electrodes were simple to attach, worked well without severe skin reactions, and were cheap. They are recommended for routine use. Smith and Nephew electrodes, a type of “multipoint electrodes” which do not require electrode jelly, frequently produced severe skin reactions, making them unsuitable for monitoring for periods exceeding 12 hours.

Hubner, P. J. B.

1969-01-01

403

High frequency reference electrode  

DOEpatents

A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.

Kronberg, J.W.

1994-05-31

404

High frequency reference electrode  

DOEpatents

A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo'' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.

Kronberg, J.W.

1991-03-05

405

Compact fission counter for DANCE  

SciTech Connect

The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF{sub 2} crystals with equal solid-angle coverage. DANCE is a 4{pi} {gamma}-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed {gamma}-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture {gamma} rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to {alpha} particles, which is important for experiments with {alpha}-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from {alpha}'s. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed counter and still be able to maintain a stable operation under extreme radioactivity and the ability to separate fission fragments from {alpha}'s. In the following sections, the description is given for the design and performance of this new compact PPAC, for studying the neutron-induced reactions on actinides using DANCE at LANL.

Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

2010-11-06

406

Fabrication and characterization of photo cathode materials for transparent organic light-emitting diodes  

NASA Astrophysics Data System (ADS)

In this work structural composition and fabrication process of cathode for transparent OLED were investigated. Using a LiF/Al/Ag/Alq3 semitransparent cathode and a Mg:Ag/ITO cathode, green fluorescent transparent organic light-emitting devices (TOLEDs) were fabricated. ITO was evaporated as a cathode onto a thin Mg:Ag layer by DC magnetron sputtering method with the assistance of tiny H2O vapor during deposition process. The fabrication of LiF/Al/Ag/Alq3 electrode was processed without breaking the vacuum. At a bias of 15 V, the luminance of the TOLED with Mg:Ag/ITO and LiF/Al/Ag/Alq3 cathode were 3016 and 4535 cd/m2, respectively. The results indicate that LiF/Al/Ag/Alq3 electrode can be used as an effective and stable cathode in TOLEDs.

Lin, Hui; Yu, Junsheng; Wang, Nana; Huang, Chunhua; Jiang, Yadong

2010-05-01

407

Small hysteresis nanocarbon-based integrated circuits on flexible and transparent plastic substrate.  

PubMed

We report small hysteresis integrated circuits by introducing monolayer graphene for the electrodes and a single-walled carbon nanotube network for the channel. Small hysteresis of the device originates from a defect-free graphene surface, where hysteresis was modulated by oxidation. This uniquely combined nanocarbon material device with transparent and flexible properties shows remarkable device performance; subthreshold voltage of 220 mV decade(-1), operation voltage of less than 5 V, on/off ratio of approximately 10(4), mobility of 81 cm(2) V(-1) s(-1), transparency of 83.8% including substrate, no significant transconductance changes in 1000 times of bending test, and only 36% resistance decrease at a tensile strain of 50%. Furthermore, because of the nearly Ohmic contact nature between the graphene and carbon nanotubes, this device demonstrated a contact resistance 100 times lower and a mobility 20 times higher, when compared to an Au electrode. PMID:21322606

Yu, Woo Jong; Lee, Si Young; Chae, Sang Hoon; Perello, David; Han, Gang Hee; Yun, Minhee; Lee, Young Hee

2011-02-15

408

High performance cermet electrodes  

DOEpatents

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.

Isenberg, Arnold O. (Forest Hills Boro, PA); Zymboly, Gregory E. (Penn Hills, PA)

1986-01-01

409

MoOx modified ZnGaO based transparent conducting oxides  

Microsoft Academic Search

We report here the growth of high work function bilayered structures of thin MoOx (2.0transparent electrode applications. It was found that the films were highly textured along [0001] direction. The crystalline quality of the films deposited at different substrate temperatures was investigated

Titas Dutta; P. Gupta; V. Bhosle; J. Narayan

2009-01-01

410

Reduced graphene oxide nanoribbon networks: a novel approach towards scalable fabrication of transparent conductive films.  

PubMed

An innovative approach is developed for the high-throughput, large-area, and low-cost fabrication of reduced graphene oxide (RGO) nanoribbon networks by using electrospun polymer-based nanowires as the etching mask. Combined with their tunable, controllable structures and transmittance/conductivity properties, the as-fabricated RGO nanoribbon networks exhibit potential as transparent conductive film electrodes, for example, in electrochromic devices. PMID:23213044

He, Haiyong; Li, Xianglong; Wang, Jie; Qiu, Tengfei; Fang, Yan; Song, Qi; Luo, Bin; Zhang, Xianfeng; Zhi, Linjie

2012-12-04

411

Optical phase modulator utilizing a transparent piezofilm for use with the extrinsic fiber interferometer  

NASA Astrophysics Data System (ADS)

A piezoelectnc polyvinylidene flouride (PVF2) film with transparent indium tin oxide electrode metallization is placed directly in the path of a single mode fiber output, to form an extrinsic optical interferometer. This device can be used concurrently with another extrinsic inteferometer on a fiber directional coupler to generate a carrier phase modulation on which the signal phase shift is superimposed. Experimental results of the induced phase shifting coefficient are presented for two arrangements of the piezofilm differing in their boundary clamping conditions.

Sudarshanam, V. S.; Claus, Richard O.

1993-03-01

412

Electrical control of kinesin-microtubule motility using a transparent functionalized-graphene substrate  

NASA Astrophysics Data System (ADS)

We report a new strategy to selectively localize and control microtubule translocation via electrical control of microtubules using a microfabricated channel on a functionalized-graphene electrode with high transparency and conductivity. A patterned SU-8 film acts as an insulation layer which shields the electrical field generated by the graphene underneath while the localized electric field on the exposed graphene surface guides the negatively charged microtubules. This is the first report showing that functionalized graphene can support and control microtubule motility.

Kim, Eunji; Byun, Kyung-Eun; Choi, Dong Shin; Lee, Dong Jun; Cho, Duck Hyung; Lee, Byung Yang; Yang, Heejun; Heo, Jinseong; Chung, Hyun-Jong; Seo, Sunae; Hong, Seunghun

2013-05-01

413

Metamaterial transparency induced by cooperative electromagnetic interactions.  

PubMed

We propose a cooperative asymmetry-induced transparency, CAIT, formed by collective excitations in metamaterial arrays of discrete resonators. CAIT can display a sharp transmission resonance even when the constituent resonators individually exhibit broad resonances. We further show how dynamically reconfiguring the metamaterial allows one to actively control the transparency. While reminiscent of electromagnetically induced transparency, which can be described by independent emitters, CAIT relies on a cooperative response resulting from strong radiative couplings between the resonators. PMID:24138271

Jenkins, Stewart D; Ruostekoski, Janne

2013-09-30

414

Metamaterial Transparency Induced by Cooperative Electromagnetic Interactions  

NASA Astrophysics Data System (ADS)

We propose a cooperative asymmetry-induced transparency, CAIT, formed by collective excitations in metamaterial arrays of discrete resonators. CAIT can display a sharp transmission resonance even when the constituent resonators individually exhibit broad resonances. We further show how dynamically reconfiguring the metamaterial allows one to actively control the transparency. While reminiscent of electromagnetically induced transparency, which can be described by independent emitters, CAIT relies on a cooperative response resulting from strong radiative couplings between the resonators.

Jenkins, Stewart D.; Ruostekoski, Janne

2013-10-01

415

Transparency in nanophotonic quantum wires  

NASA Astrophysics Data System (ADS)

We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schrödinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

Singh, Mahi R.

2009-03-01

416

A beam counter for intense muon beams  

Microsoft Academic Search

A plastic beam counter and associated photomultiplier base are constructed for use at intense muon beams (up to several 107 mu-\\/s). In order to enable a most sensitive recognition of beam background, the beam counter signal is recorded with a fast waveform digitizer. A peak finding routine is developed that makes use of a generalized second-difference signal calculated from the

L. Ricken; T. Kozlowski

1991-01-01

417

An Automatic Cloud Condensation Nuclei Counter  

Microsoft Academic Search

A cloud condensation nuclei counter has been developed in which the concentration of water droplets which form on cloud condensation nuclei in a large thermal diffusion chamber is determined electronically by measuring the light scattering coefficient of the cloud. The counter operates completely automatically and may be used to determine the concentration of cloud condensation nuclei in the air (active

L. F. Radke; P. V. Hobbs

1969-01-01

418

A framework for online counter terrorism  

Microsoft Academic Search

Nowadays, most of the countries have come to this conclusion that their plan for counter terrorism should be changed from ¿passive¿ to ¿active¿. Consistently, this should be reflected on the Internet as an important channel of communication and doing business in many countries. However, there are different barriers to achieve an effective online counter terrorism such as lack of ¿cooperation¿

Kiyana Zolfaghar; Arash Barfar; Shahriar Mohammadi

2009-01-01

419

Structural, chemical and electrochemical characterization of poly(3,4-Ethylenedioxythiophene) (PEDOT) prepared with various counter-ions and heat treatments  

Microsoft Academic Search

Electrochemical deposition of the conjugated polymer poly(3,4-ethylenedioxythiophene) (PEDOT) forms thin, conductive films that are especially suitable for charge transfer at the tissue–electrode interface of neural implants. For this study, the effects of counter-ion choice and annealing parameters on the electrical and structural properties of PEDOT were investigated. Films were polymerized with various organic and inorganic counter-ions. Studies of crystalline order

Zachary A. King; Charles M. Shaw; Sarah A. Spanninga; David C. Martin

2011-01-01

420

Al nanogrid electrode for ultraviolet detectors.  

PubMed

Optical properties of Al nanogrids of different pitches and gaps were investigated both theoretically and experimentally. Three-dimensional finite-difference time-domain simulation predicted that surface plasmons at the air/Al interface would enhance ultraviolet transmission through the subwavelength gaps of the nanogrid, making it an effective electrode on GaN-based photodetectors to compensate for the lack of transparent electrode and high p-type doping. The predicted transmission enhancement was verified by confocal scanning optical microscopy performed at 365 nm. The quality of the nanogrids fabricated by electron-beam lithography was verified by near-field scanning optical microscopy and scanning electron microscopy. Based on the results, the pitch and gap of the nanogrids can be optimized for the best trade-off between electrical conductivity and optical transmission at different wavelengths. Based on different cutoff wavelengths, the nanogrids can also double as a filter to render photodetectors solar-blind. PMID:21931425

Ding, G; Deng, J; Zhou, L; Gan, Q; Hwang, J C M; Dierolf, V; Bartoli, F J; Mazuir, C; Schoenfeld, W V

2011-09-15

421

Effects of heterotopic- and segmental counter-stimulation on the nociceptive withdrawal reflex in humans.  

PubMed

A nociceptive withdrawal reflex in 12 human volunteers was elicited by painful electrical stimulation applied to the cutaneous innervation area of the sural nerve. The evoked electromyographic reflex activities were recorded with surface electrodes placed on the short head of the biceps femoris muscle ipsi-lateral to sural nerve stimulation, before, during and after conditioning stimuli. The nociceptive withdrawal reflex was conditioned by nociceptive and non-nociceptive, heterotopic and segmental counter-stimulation. Heterotopic nociceptive counter-stimulation and segmental nociceptive counter-stimulation were induced by ice water applied to the contra-lateral hand and foot, respectively. Heterotopic nociceptive counter-stimulation produced a significant inhibition of the nociceptive withdrawal reflex and the associated pains rating to sural nerve stimulation. Segmental nociceptive counter-stimulation inhibited the pain rating and tended to inhibit the nociceptive withdrawal reflex. There was no obvious correlation between visual analogue scale (VAS) and the nociceptive withdrawal reflex elicited by sural nerve stimulation neither in the group nor in the individual subject. This suggests that the nociceptive withdrawal reflex cannot always be used as a quantitative measure of pain. PMID:11472308

Terkelsen, A J; Andersen, O K; Hansen, P O; Jensen, T S

2001-07-01

422

Electromechanically driven variable-focus lens based on transparent dielectric elastomer.  

PubMed

Dielectric elastomers with low elastic stiffness and high dielectric constant are smart materials that produce large strains (up to 300%) and belong to the group of electroactive polymers. Dielectric elastomer actuators are made from films of dielectric elastomers coated on both sides with compliant electrode material. Poly(3,4-ethylenedioxythiophene) (PEDOT), which is known as a transparent conducting polymer, has been widely used as an interfacial layer or polymer electrode in polymer electronic devices. In this study, we propose the transparent dielectric elastomer as a material of actuator driving variable-focus lens system using PEDOT as a transparent electrode. The variable-focus lens module has light transmittance up to 70% and maximum displacement up to 450. When voltage is applied to the fabricated lens module, optical focal length is changed. We anticipate our research to be a starting point for new model of variable-focus lens system. This system could find applications in portable devices, such as digital cameras, camcorder, and cell phones. PMID:22614602

Son, Sang-ik; Pugal, David; Hwang, Taeseon; Choi, Hyouk Ryeol; Koo, Ja Choon; Lee, Youngkwan; Kim, Kwang; Nam, Jae-Do

2012-05-20

423

Compact multiwire proportional counters for the detection of fission fragments  

SciTech Connect

Two large area multistep position sensitive (two dimensional) multiwire proportional counters have been developed for experiments involving study of fission dynamics using general purpose scattering chamber facility at IUAC. Both detectors have an active area of 20x10 cm{sup 2} and provide position signals in horizontal (X) and vertical (Y) planes, timing signal for time of flight measurements and energy signal giving the differential energy loss in the active volume. The design features are optimized for the detection of low energy heavy ions at very low gas pressures. Special care was taken in setting up the readout electronics, constant fraction discriminators for position signals in particular, to get optimum position and timing resolutions along with high count rate handling capability of low energy heavy ions. A custom made charge sensitive preamplifier, having lower gain and shorter decay time, has been developed for extracting the differential energy loss signal. The position and time resolutions of the detectors were determined to be 1.1 mm full width at half maximum (FWHM) and 1.7 ns FWHM, respectively. The detector could handle heavy ion count rates exceeding 20 kHz without any breakdown. Time of flight signal in combination with differential energy loss signal gives a clean separation of fission fragments from projectile and target like particles. The timing and position signals of the detectors are used for fission coincidence measurements and subsequent extraction of their mass, angular, and total kinetic energy distributions. This article describes systematic study of these fission counters in terms of efficiency, time resolution, count rate handling capability, position resolution, and the readout electronics. The detector has been operated with both five electrode geometry and four electrode geometry, and a comparison has been made in their performances.

Jhingan, Akhil; Sugathan, P.; Golda, K. S.; Singh, R. P.; Varughese, T. [Inter University Accelerator Centre, P.O. Box 10502, New Delhi 110067 (India); Singh, Hardev; Behera, B. R. [Department of Physics, Panjab University, Chandigarh 160014 (India); Mandal, S. K. [Department of Physics and Astrophysics, Delhi University, Delhi 110007 (India)

2009-12-15

424

A Nafion®-based co-planar electrode amperometric sensor for methanol determination in the gas phase  

Microsoft Academic Search

A co-planar electrode device, fabricated with all electrodes (working, counter and reference) on the same face of a Nafion®\\u000a polymer electrolyte membrane, is proposed for the amperometric detection of gaseous methanol using Pt as the working electrode.\\u000a Clear voltammetry is obtained for methanol oxidation from its vapours in equilibrium with methanol aqueous solutions, both\\u000a in the absence and presence of

K. Wallgren; S. Sotiropoulos

2009-01-01

425

Bottom-up growth of fully transparent contact layers of indium tin oxide nanowires for light-emitting devices.  

PubMed

Thin layers of indium tin oxide are widely used as transparent coatings and electrodes in solar energy cells, flat-panel displays, antireflection coatings, radiation protection and lithium-ion battery materials, because they have the characteristics of low resistivity, strong absorption at ultraviolet wavelengths, high transmission in the visible, high reflectivity in the far-infrared and strong attenuation in the microwave region. However, there is often a trade-off between electrical conductivity and transparency at visible wavelengths for indium tin oxide and other transparent conducting oxides. Here, we report the growth of layers of indium tin oxide nanowires that show optimum electronic and photonic properties and demonstrate their use as fully transparent top contacts in the visible to near-infrared region for light-emitting devices. PMID:19350034

O'Dwyer, C; Szachowicz, M; Visimberga, G; Lavayen, V; Newcomb, S B; Torres, C M Sotomayor

2009-02-01

426

Fabrication of amperometric electrodes.  

PubMed

Carbon fiber electrodes are crucial for the detection of catecholamine release from vesicles in single cells for amperometry measurements. Here, we describe the techniques needed to generate low noise (<0.5 pA) electrodes. The techniques have been modified from published descriptions by previous researchers (1,2). Electrodes are made by preparing carbon fibers and threading them individually into each capillary tube by using a vacuum with a filter to aspirate the fiber. Next, the capillary tube with fiber is pulled by an electrode puller, creating two halves, each with a fine-pointed tip. The electrodes are dipped in hot, liquid epoxy mixed with hardener to create an epoxy-glass seal. Lastly, the electrodes are placed in an oven to cure the epoxy. Careful handling of the electrodes is critical to ensure that they are made consistently and without damage. This protocol shows how to fabricate and cut amperometric electrodes for recording from single cells. PMID:19415069

Pike, Carolyn M; Grabner, Chad P; Harkins, Amy B

2009-05-04

427

Nickel Hydroxide Electrode Research.  

National Technical Information Service (NTIS)

The report discusses results of work performed to develop an improved nickel hydroxide electrode for use in rechargable alkaline electrodes for aerospace applications. Voltametric cycling studies have shown that all deliberate additions of cations (cobalt...

H. A. Christopher J. L. Weininger J. G. Ruzzo R. F. Thornton P. J. Moran

1970-01-01

428

Dry electrodes for electrocardiography.  

PubMed

Patient biopotentials are usually measured with conventional disposable Ag/AgCl electrodes. These electrodes provide excellent signal quality but are irritating for long-term use. Skin preparation is usually required prior to the application of electrodes such as shaving and cleansing with alcohol. To overcome these difficulties, researchers and caregivers seek alternative electrodes that would be acceptable in clinical and research environments. Dry electrodes that operate without gel, adhesive or even skin preparation have been studied for many decades. They are used in research applications, but they have yet to achieve acceptance for medical use. So far, a complete comparison and evaluation of dry electrodes is not well described in the literature. This work compares dry electrodes for biomedical use and physiological research, and reviews some novel systems developed for cardiac monitoring. Lastly, the paper provides suggestions to develop a dry-electrode-based system for mobile and long-term cardiac monitoring applications. PMID:23969948

Meziane, N; Webster, J G; Attari, M; Nimunkar, A J

2013-08-23

429

Reversible Oxygen Electrodes.  

National Technical Information Service (NTIS)

Achievements during the course of the Project have been briefly summarized. A rotating disk electrode with a concentric ring was shown to be a valuable tool in discriminating between possible mechanisms in 02 reduction. On platinum electrodes in highly pu...

M. Genshaw V. Brusic A. Damjanovic

1964-01-01

430

Low resistance fuel electrodes  

DOEpatents

An electrode 6 bonded to a solid, ion conducting electrolyte 5 is made, where the electrode 6 comprises a ceramic metal oxide 18, metal particles 17, and heat stable metal fibers 19, where the metal fibers provide a matrix structure for the electrode. The electrolyte 5 can be bonded to an air electrode cathode 4, to provide an electrochemical cell 2, preferably of tubular design.

Maskalick, Nichols J. (Pittsburgh, PA); Folser, George R. (Lower Burrell, PA)

1989-01-01

431

Are shadows transparent? An investigation on white, shadows and transparency in pictures  

Microsoft Academic Search

Shadow perception and transparency perception appear to use very similar rules, to the point that from the perceptual point of view shadows have been considered an instance of transparent objects. We claim that in spite of the similarities, shadows ought not to be considered transparent entities. The discussion has consequences both for the issue of the location of shadows, and

Roberto Casati

432

21 CFR 866.2180 - Manual colony counter.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Manual colony counter. 866.2180 Section 866.2180...Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for...

2010-04-01

433

21 CFR 866.2170 - Automated colony counter.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Automated colony counter. 866.2170 Section 866.2170...Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device...

2009-04-01

434

21 CFR 866.2170 - Automated colony counter.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Automated colony counter. 866.2170 Section 866.2170...Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device...

2010-04-01

435

21 CFR 866.2180 - Manual colony counter.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Manual colony counter. 866.2180 Section 866.2180...Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for...

2009-04-01

436

21 CFR 892.1130 - Nuclear whole body counter.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Nuclear whole body counter. 892.1130 ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...892.1130 Nuclear whole body counter. (a) Identification. A nuclear whole body counter is a device...

2013-04-01

437

Electrodes for Electrochemical Supercapacitors  

Microsoft Academic Search

Manganese dioxide nanoparticles were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors (ES) were fabricated by impregnation of slurries of the manganese dioxide nanoparticles and carbon black into porous nickel foam current collectors. In the composite electrodes, carbon black nanoparticles formed a secondary conductivity network within the nickel foam cells. Obtained composite electrodes, containing manganese dioxide and

Gideon Moses Jacob; Quan Min Yang; Igor Zhitomirsky

2009-01-01

438

Electrically conductive diamond electrodes  

DOEpatents

An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

Swain, Greg (East Lansing, MI); Fischer, Anne (Arlington, VA),; Bennett, Jason (Lansing, MI); Lowe, Michael (Holt, MI)

2009-05-19

439

Floating electrode dielectrophoresis.  

PubMed

In practice, dielectrophoresis (DEP) devices are based on micropatterned electrodes. When subjected to applied voltages, the electrodes generate nonuniform electric fields that are necessary for the DEP manipulation of particles. In this study, electrically floating electrodes are used in DEP devices. It is demonstrated that effective DEP forces can be achieved by using floating electrodes. Additionally, DEP forces generated by floating electrodes are different from DEP forces generated by excited electrodes. The floating electrodes' capabilities are explained theoretically by calculating the electric field gradients and demonstrated experimentally by using test-devices. The test-devices show that floating electrodes can be used to collect erythrocytes (red blood cells). DEP devices which contain many floating electrodes ought to have fewer connections to external signal sources. Therefore, the use of floating electrodes may considerably facilitate the fabrication and operation of DEP devices. It can also reduce device dimensions. However, the key point is that DEP devices can integrate excited electrodes fabricated by microtechnology processes and floating electrodes fabricated by nanotechnology processes. Such integration is expected to promote the use of DEP devices in the manipulation of nanoparticles. PMID:17117384

Golan, Saar; Elata, David; Orenstein, Meir; Dinnar, Uri

2006-12-01

440

HIGH VOLTAGE ELECTRODES  

Microsoft Academic Search

S>This patent relates to electrode structure for creating an intense ; direct current electric field which may have a field strength of the order of two ; to three times that heretofore obtained, with automatic suppression of arcing. ; The positive electrode is a conventional conductive material such as copper while ; the negative electrode is made from a special

1963-01-01

441

A Simple Hydrogen Electrode  

ERIC Educational Resources Information Center

|This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

Eggen, Per-Odd

2009-01-01

442

Platinized Silver Chloride Electrode  

Microsoft Academic Search

A hybrid electrode made by platinizing silver-silver chloride has been found to combine the stable potential and low direct-current resistance properties of a silver-silver chloride electrode with the low high-frequency impedance characteristic of a platinized platinum electrode.

Kenneth S. Cole; Uichiro Kishimoto

1962-01-01

443

A Simple, Transparent Fume Hood  

NASA Astrophysics Data System (ADS)

An inexpensive transparent fume hood can be constructed from a clear-plastic two-liter soft drink bottle that is cut just above the base. A length of vacuum tubing is secured to the opening of the bottle using black electrical tape. The tubing is then connected to a water aspirator. Beakers or flasks easily fit inside the bottle, and the bottle may be secured with a clamp and ring stand for added stability. This device has been used to collect the noxious NO2 gas generated from the reaction of copper metal with nitric acid. It also may be used in the collection of other gases. It should not be used to collect gases that are not water-soluble or in experiments that involve open flames.

Fredericks, John

1998-10-01

444

Broadband cavity electromagnetically induced transparency  

SciTech Connect

Cavity electromagnetically induced transparency (EIT) is created in a three-level atomic system confined in a cavity and coupled to a free-space control laser and is manifested as a narrow transmission peak of a probe laser coupled into the cavity mode and tuned to the two-photon Raman resonance with the control laser. Cavity EIT can be observed with a control laser detuned from the atomic transition frequency in a range limited by the vacuum Rabi splitting of two cavity-atom normal modes. This leads to the broadband cavity EIT obtained in the coupled-cavity-atom system with a free-space, broadband control laser. We report an experimental observation of broadband cavity EIT in cold Rb atoms with a frequency-modulated control laser and discuss its application in multichannel and multifrequency light memory.

Wei Xiaogang [Department of Physics, Florida International University, Miami, Florida 33199 (United States); College of Physics, Jilin University, Changchun 130023 (China); Wang Yanhua [Department of Physics, Florida International University, Miami, Florida 33199 (United States); College of Physics and Electronics, Shanxi University, Taiyuan 030006 (China); Zhang Jiepeng [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Physics Division P-23, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Zhu Yifu [Department of Physics, Florida International University, Miami, Florida 33199 (United States)

2011-10-15

445

A germanate transparent conductive oxide  

PubMed Central

Wide bandgap conductors such as In2O3 and ZnO are used as transparent conducting oxides (TCOs). To date, TCOs are realized using post transition metal cations with largely spread s-orbitals such as In3+, Sn4+, Zn2+ and Cd2+. On the other hand, no good electronic conductor has been realized in oxides of Al, Si and Ge. Here we report the conversion of an oxide of Ge into a good electronic conductor by employing the concept of superdegeneracy. We find that cubic SrGeO3, synthesized under high pressure, displays a direct bandgap of 3.5?eV, a carrier mobility of 12?cm2(Vs)?1, and conductivities of 3?Scm?1 (DC) and 400?Scm?1 (optical conductivity). This is the first Ge-based electronic conductive oxide, and expands the family of TCOs from ionic oxides to covalent oxides.

Mizoguchi, Hiroshi; Kamiya, Toshio; Matsuishi, Satoru; Hosono, Hideo

2011-01-01

446

PEDOT as an alignment layer and electrode in AFLC devices  

NASA Astrophysics Data System (ADS)

PEDOT [Poly (3, 4-ethylenedioxythiophene) poly (styrenesulfonate)] is a material typically used organic light emission displays (OLEDs) manufactured as a conductor, or rather, as a hole injector. In this paper, three different issues have been studied: the use of rubbed PEDOT as alignment layer, the resistivity of the applied PEDOT layers, i.e., its potential as a replacement of ITO electrodes, and the induction of asymmetry in the electro-optical response of liquid crystal cells by assembling the display with dissimilar coated aligning surfaces — PEDOT on one side and buffed nylon on the counter electrode

Medialdea, D. P.; Bennis, N.; Cerrolaza, B.; Quintana, X.; Otón, J. M.; Arredondo, B.; Romero, B.; Geday, M. A.

2009-03-01

447

Fabrication of Transparent Capacitive Structure by Self-Assembled Thin Films  

SciTech Connect

An approach to fabricating transparent electronic devices by using nanomaterial and nanofabrication is presented in this paper. A see-through capacitor is constructed from selfassembled silica nanoparticle layers that are stacked on the transparent substrate. The electrodes are made of indium tin oxide. Unlike the traditional processes used to fabricate such devices, the self-assembly approach enables one to synthesize the thin film layers at lower temperature and cost, and with a broader availability of nanomaterials. The vertical dimension of the selfassembled thin films can be precisely controlled, as well as the molecular order in the thin film layers. The shape of the capacitor is generated by planar micropatterning. The quartz crystal demonstrates the steady growth of the silica nanoparticle multilayer. In addition, because the nanomaterial synthesis and the device fabrication steps are separate, the device is not affected by the harsh conditions required for the material synthesis. A clear pattern is allowed over a large area on the substrate. The prepared capacitive structure has an optical transparency higher than 92% over the visible spectrum. The capacitive impedance is measured at different frequencies and fit the theoretical results. As one of the fundamental components, this type of capacitive structure can serve in the transparent circuits, interactive media and sensors, as well as being applicable to other transparent devices.

Zhang, Q.; Shing, Y. J.; Hua, Feng; Saraf, Laxmikant V.; Matson, Dean W.

2008-06-01

448

Transparent US monetary policy: theory and tests  

Microsoft Academic Search

In 1994, the Federal Reserve System moved to a more transparent reporting of monetary policy. This article assesses the impact of monetary policy transparency on uncertainty about future monetary policy using T-bill rate forecast dispersions and ex post forecast errors from the Survey of Professional Forecasters as a proxy for monetary policy uncertainty. The empirical findings confirm that Federal Reserve

Marc D. Hayford; A. G. Malliaris

2011-01-01

449

Transparent US monetary policy: theory and tests  

Microsoft Academic Search

In 1994, the Federal Reserve System moved to a more transparent reporting of monetary policy. This article assesses the impact of monetary policy transparency on uncertainty about future monetary policy using T-bill rate forecast dispersions and ex post forecast errors from the Survey of Professional Forecasters as a proxy for monetary policy uncertainty. The empirical findings confirm that Federal Reserve

Marc D. Hayford; A. G. Malliaris

2012-01-01

450

Dirty Glass: Rendering Contamination on Transparent Surfaces  

Microsoft Academic Search

Rendering of clean transparent objects has been well studied in computer graphics. However, real-world transpar- ent objects are seldom clean—their surfaces have a variety of contaminants such as dust, dirt, and lipids. These contaminants produce a number of complex volumetric scattering effects that must be taken into account when creating photorealistic renderings. In this paper, we take a step toward

Jinwei Gu; Ravi Ramamoorthi; Peter N. Belhumeur; Shree K. Nayar

2007-01-01

451

Light scattering in transparent glass ceramics  

Microsoft Academic Search

Transparent glass ceramic materials, with microstructures comprised of dispersed nanocrystallites in a residual glass matrix, offer the prospect of nonlinear optical properties. However, good transparency requires low optical scattering and low atomic absorption. The attenuation of light due to scattering (turbidity) will depend upon the difference in refractive index of the two phases and the size and distribution of crystals

Shaun C. Hendy

2002-01-01

452

Rare-earth-doped transparent glass ceramics  

Microsoft Academic Search

Glass ceramics are a known class of polycrystalline ceramic materials, where, depending on the glass matrix and the particular crystalline phases, one can obtain materials with improved mechanical, thermal, electrical or optical properties. The characteristics and applications of optical glass ceramics are reviewed, with particular emphasis on rare-earth-doped transparent glass ceramics for photonics, including the search for new transparent glass

M Clara Gonçalves; Luís F Santos; Rui M Almeida

2002-01-01

453

Transparent compact ceramics: Inherent physical issues  

Microsoft Academic Search

The overview focuses on inherent optical properties, governed by composition and the state of the crystal lattice, and on the interference of these properties with the microstructural optimization of transparent ceramics (e.g. the dependence of the tolerable pore size or grain size on the refractive index). Starting with the general difference between the dispersive performances n(?) of glasses and transparent

A. Krell; J. Klimke; T. Hutzler

2009-01-01

454

Modelling transparent ceramics to improve military armour  

Microsoft Academic Search

The dominant materials solution used for ballistic transparency protection of armoured tactical platforms in commercial and military applications is low cost glass backed by polycarbonate. Development of next generation ceramics is critical to offering enhanced protection capability and extended service performance for future armoured windows to the soldier. Due to the high cost of testing transparent ceramics, a modelling approach

J. M. Sands; C. G. Fountzoulas; G. A. Gilde; P. J. Patel

2009-01-01

455

Design tools for transparent optical networks  

Microsoft Academic Search

Optical technology promises to revolutionize data networking by providing enormous bandwidth for data transport at minimal cost. A key to cost reduction is to increase transparency, that is, to keep a data stream encoded as an optical signal for as long as possible. Wavelength switching increases transparency by allowing different data streams, each encoded in a different wavelength of light,

Chandra Chekuri; Paul Claisse; René-jean Essiambre; Steven Fortune; Daniel C. Kilper; Wonsuck Lee; Nachi K. Nithi; Iraj Saniee; F. Bruce Shepherd; Christopher A. White; Gordon T. Wilfong; Lisa Zhang

2006-01-01

456

Transparent ultrananocrystalline diamond films on quartz substrate  

Microsoft Academic Search

Highly transparent ultrananocrystalline diamond (UNCD) films were deposited on quartz substrates using microwave plasma enhanced chemical vapor deposition (MPECVD) method. Low temperature growth of high quality transparent UNCD films was achieved by without heating the substrates prior to the deposition. Additionally, a new method to grow NCD and microcrystalline diamond (MCD) films on quartz substrates has been proposed. Field emission

P. T. Joseph; Nyan-Hwa Tai; Yi-Chun Chen; Hsiu-Fung Cheng; I-Nan Lin

2008-01-01

457

Transparency Halation Measurement, Method and Apparatus.  

National Technical Information Service (NTIS)

For determining the extent of surface deterioration of a transparency, a method and apparatus is provided for measuring light scatter or halation produced by the deterioration. An intense light source is placed on one side of the transparency to be tested...

L. V. Genco

1981-01-01

458

Transparency Halation Measurement Method and Apparatus.  

National Technical Information Service (NTIS)

For determining the extent of surface deterioration of a transparency, a method and apparatus is provided for measuring light scatter or halation produced by the deterioration. An intense light source is placed on one side of the transparency to be tested...

L. V. Genco R. G. Eggleston

1983-01-01