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Sample records for electrochromic devices deposited

  1. Electrochromic device

    SciTech Connect

    Schwendemanm, Irina G.; Polcyn, Adam D.; Finley, James J.; Boykin, Cheri M.; Knowles, Julianna M.

    2011-03-15

    An electrochromic device includes a first substrate spaced from a second substrate. A first conductive member is formed over at least a portion of the first substrate. A first electrochromic material is formed over at least a portion of the first conductive member. The first electrochromic material includes an organic material. A second conductive member is formed over at least a portion of the second substrate. A second electrochromic material is formed over at least a portion of the second conductive member. The second electrochromic material includes an inorganic material. An ionic liquid is positioned between the first electrochromic material and the second electrochromic material.

  2. Electrochromic devices

    DOEpatents

    Allemand, Pierre M.; Grimes, Randall F.; Ingle, Andrew R.; Cronin, John P.; Kennedy, Steve R.; Agrawal, Anoop; Boulton, Jonathan M.

    2001-01-01

    An electrochromic device is disclosed having a selective ion transport layer which separates an electrochemically active material from an electrolyte containing a redox active material. The devices are particularly useful as large area architectural and automotive glazings due to there reduced back reaction.

  3. Electrochromic Devices Deposited on Low-Temperature Plastics by Plasma-Enhanced Chemical Vapor Deposition

    SciTech Connect

    Robbins, Joshua; Seman, Michael

    2005-09-20

    Electrochromic windows have been identified by the Basic energy Sciences Advisory committee as an important technology for the reduction of energy spent on heating and cooling in residential and commercial buildings. Electrochromic devices have the ability to reversibly alter their optical properties in response to a small electric field. By blocking ultraviolet and infrared radiation, while modulating the incoming visible radiation, electrochromics could reduce energy consumption by several Quads per year. This amounts to several percent of the total annual national energy expenditures. The purpose of this project was to demonstrate proof of concept for using plasma-enhanced chemical vapor deposition (PECVD) for depositing all five layers necessary for full electrochromic devices, as an alternative to sputtering techniques. The overall goal is to produce electrochromic devices on flexible polymer substrates using PECVD to significantly reduce the cost of the final product. We have successfully deposited all of the films necessary for a complete electrochromic devices using PECVD. The electrochromic layer, WO3, displayed excellent change in visible transmission with good switching times. The storage layer, V2O5, exhibited a high storage capacity and good clear state transmission. The electrolyte, Ta2O5, was shown to functional with good electrical resistivity to go along with the ability to transfer Li ions. There were issues with leakage over larger areas, which can be address with further process development. We developed a process to deposit ZnO:Ga with a sheet resistance of < 50 W/sq. with > 90% transmission. Although we were not able to deposit on polymers due to the temperatures required in combination with the inverted position of our substrates. Two types of full devices were produced. Devices with Ta2O5 were shown to be functional using small aluminum dots as the top contact. The polymer electrolyte devices were shown to have a clear state transmission of

  4. Nanostructured transparent conducting oxide electrochromic device

    DOEpatents

    Milliron, Delia; Tangirala, Ravisubhash; Llordes, Anna; Buonsanti, Raffaella; Garcia, Guillermo

    2016-05-17

    The embodiments described herein provide an electrochromic device. In an exemplary embodiment, the electrochromic device includes (1) a substrate and (2) a film supported by the substrate, where the film includes transparent conducting oxide (TCO) nanostructures. In a further embodiment, the electrochromic device further includes (a) an electrolyte, where the nanostructures are embedded in the electrolyte, resulting in an electrolyte, nanostructure mixture positioned above the substrate and (b) a counter electrode positioned above the mixture. In a further embodiment, the electrochromic device further includes a conductive coating deposited on the substrate between the substrate and the mixture. In a further embodiment, the electrochromic device further includes a second substrate positioned above the mixture.

  5. Development of electrochromic devices.

    PubMed

    Pawlicka, A

    2009-01-01

    Electrochromic devices (ECD) are systems of considerable commercial interest due to their controllable transmission, absorption and/or reflectance. For instance, these devices are mainly applied to glare attenuation in automobile rearview mirrors and also in some smart windows that can regulate the solar gains of buildings. Other possible applications of ECDs include solar cells, small- and large-area flat panel displays, and frozen food monitoring and document authentication also are of great interest. Over the past 20 years almost 1000 patents and 1500 papers in journals and proceedings have been published with the key words "electrochromic windows". Most of these documents report on materials for electrochromic devices and only some of them about complete electrochromic devices. This paper describes the first patents and some of the recent ones on ECDs, whose development is possible due to the advances in nanotechnology. PMID:19958283

  6. Integrated device architectures for electrochromic devices

    SciTech Connect

    Frey, Jonathan Mack; Berland, Brian Spencer

    2015-04-21

    This disclosure describes systems and methods for creating monolithically integrated electrochromic devices which may be a flexible electrochromic device. Monolithic integration of thin film electrochromic devices may involve the electrical interconnection of multiple individual electrochromic devices through the creation of specific structures such as conductive pathway or insulating isolation trenches.

  7. Electrochromic optical switching device

    SciTech Connect

    Lampert, C.M.; Visco, S.J.

    1992-08-25

    An electrochromic cell is disclosed which comprises an electrochromic layer, a polymerizable organo-sulfur layer which comprises the counter electrode of the structure, and an ionically conductive electronically insulating material which comprises the separator between the electrodes. In a preferred embodiment, both the separator and the organo-sulfur electrode (in both its charged and uncharged states) are transparent either to visible light or to the entire solar spectrum. An electrochromic device is disclosed which comprises such electrodes and separator encased in glass plates on the inner surface of each of which is formed a transparent electrically conductive film in respective electrical contact with the electrodes which facilitates formation of an external electrical connection or contact to the electrodes of the device to permit electrical connection of the device to an external potential source. 3 figs.

  8. Electrochromic optical switching device

    SciTech Connect

    Lampert, Carl M.; Visco, Steven J.

    1992-01-01

    An electrochromic cell is disclosed which comprises an electrochromic layer, a polymerizable organo-sulfur layer which comprises the counter electrode of the structure, and an ionically conductive electronically insulating material which comprises the separator between the electrodes. In a preferred embodiment, both the separator and the organo-sulfur electrode (in both its charged and uncharged states) are transparent either to visible light or to the entire solar spectrum. An electrochromic device is disclosed which comprises such electrodes and separator encased in glass plates on the inner surface of each of which is formed a transparent electrically conductive film in respective electrical contact with the electrodes which facilitates formation of an external electrical connection or contact to the electrodes of the device to permit electrical connection of the device to an external potential source.

  9. Next-Generation Multifunctional Electrochromic Devices.

    PubMed

    Cai, Guofa; Wang, Jiangxin; Lee, Pooi See

    2016-08-16

    The rational design and exploration of electrochromic devices will find a wide range of applications in smart windows for energy-efficient buildings, low-power displays, self-dimming rear mirrors for automobiles, electrochromic e-skins, and so on. Electrochromic devices generally consist of multilayer structures with transparent conductors, electrochromic films, ion conductors, and ion storage films. Synthetic strategies and new materials for electrochromic films and transparent conductors, comprehensive electrochemical kinetic analysis, and novel device design are areas of active study worldwide. These are believed to be the key factors that will help to significantly improve the electrochromic performance and extend their application areas. In this Account, we present our strategies to design and fabricate electrochromic devices with high performance and multifunctionality. We first describe the synthetic strategies, in which a porous tungsten oxide (WO3) film with nearly ideal optical modulation and fast switching was prepared by a pulsed electrochemical deposition method. Multiple strategies, such as sol-gel/inkjet printing methods, hydrothermal/inkjet printing methods, and a novel hybrid transparent conductor/electrochromic layer have been developed to prepare high-performance electrochromic films. We then summarize the recent advances in transparent conductors and ion conductor layers, which play critial roles in electrochromic devices. Benefiting from the developments of soft transparent conductive substrates, highly deformable electrochromic devices that are flexible, foldable, stretchable, and wearable have been achieved. These emerging devices have great potential in applications such as soft displays, electrochromic e-skins, deformable electrochromic films, and so on. We finally present a concept of multifunctional smart glass, which can change its color to dynamically adjust the daylight and solar heat input of the building or protect the users' privacy

  10. Next-Generation Multifunctional Electrochromic Devices.

    PubMed

    Cai, Guofa; Wang, Jiangxin; Lee, Pooi See

    2016-08-16

    The rational design and exploration of electrochromic devices will find a wide range of applications in smart windows for energy-efficient buildings, low-power displays, self-dimming rear mirrors for automobiles, electrochromic e-skins, and so on. Electrochromic devices generally consist of multilayer structures with transparent conductors, electrochromic films, ion conductors, and ion storage films. Synthetic strategies and new materials for electrochromic films and transparent conductors, comprehensive electrochemical kinetic analysis, and novel device design are areas of active study worldwide. These are believed to be the key factors that will help to significantly improve the electrochromic performance and extend their application areas. In this Account, we present our strategies to design and fabricate electrochromic devices with high performance and multifunctionality. We first describe the synthetic strategies, in which a porous tungsten oxide (WO3) film with nearly ideal optical modulation and fast switching was prepared by a pulsed electrochemical deposition method. Multiple strategies, such as sol-gel/inkjet printing methods, hydrothermal/inkjet printing methods, and a novel hybrid transparent conductor/electrochromic layer have been developed to prepare high-performance electrochromic films. We then summarize the recent advances in transparent conductors and ion conductor layers, which play critial roles in electrochromic devices. Benefiting from the developments of soft transparent conductive substrates, highly deformable electrochromic devices that are flexible, foldable, stretchable, and wearable have been achieved. These emerging devices have great potential in applications such as soft displays, electrochromic e-skins, deformable electrochromic films, and so on. We finally present a concept of multifunctional smart glass, which can change its color to dynamically adjust the daylight and solar heat input of the building or protect the users' privacy

  11. Sol-gel deposited electrochromic coatings

    SciTech Connect

    Ozer, N.; Lampert, C.M.

    1995-06-01

    Electrochromic devices have increasing application in display devices, switchable mirrors and smart windows. A variety of vacuum deposition technologies have been used to make electrochromic devices. The sol- gel process offers an alternative approach to the synthesis of optical quality and low cost electrochromic device layers. This study summarizes the developments in sol-gel deposited electrochromic films. The sol-gel process involves the formation of oxide networks upon hydrolysis-condensation of alkoxide precursors. In this study we cover the sol-gel deposited oxides of WO[sub 3], V[sub 2]O[sub 5], TiO[sub 2], Nb[sub 2]O[sub 5], and NiO[sub x].

  12. Electrochromic Device with Polymer Electrolyte

    NASA Astrophysics Data System (ADS)

    Solovyev, Andrey A.; Zakharov, Alexander N.; Rabotkin, Sergey V.; Kovsharov, Nikolay F.

    2016-08-01

    In this study a solid-state electrochromic device (ECD) comprised of a WO3 and Prussian blue (Fe4[Fe(CN)6]3) thin film couple with a Li+-conducting solid polymer electrolyte is discussed. WO3 was deposited on K-Glass substrate by magnetron sputtering method, while Prussian blue layer was formed on the same substrate by electrodeposition method. The parameters of the electrochromic device K-Glass/WO3/Li+-electrolyte/PB/K-Glass, such as change of transmittance, response time and stability were successfully tested using coupled optoelectrochemical methods. The device was colored or bleached by the application of +2 V or -2 V, respectively. Light modulation with transmittance variation of up to 59% and coloration efficiency of 43 cm2/C at a wavelength of 550 nm were obtained. Numerous switching of the ECD over 1200 cycles without the observation of significant degradation has been demonstrated.

  13. Electrochromic display device

    NASA Astrophysics Data System (ADS)

    Nicholson, M. M.

    1984-07-01

    This invention relates to electrochromic devices. In one aspect it relates to electrically controllable display devices. In another aspect it relates to electrically tunable optical or light filters. In yet another aspect it relates to a chemical sensor device which employs a color changing film. There are many uses for electrically controllable display devices. A number of such devices have been in commercial use for some time. These display devices include liquid crystal displays, light emitting diode displays, plasma displays, and the like. Light emitting diode displays and plasma display panels both suffer from the fact that they are active. Light emissive devices which require substantial power for their operation, In addition, it is difficult to fabricate light emitting diode displays in a manner which renders them easily distinguishable under bright ambient illumination. Liquid crystal displays suffer from the disadvantage that they are operative only over a limited temperature range and have substantially no memory within the liquid crystal material.

  14. Physics and applications of electrochromic devices

    NASA Astrophysics Data System (ADS)

    Pawlicka, Agnieszka; Avellaneda, Cesar O.

    2003-07-01

    Solid state electrochromic devices (ECD) are of considerable technological and commercial interest because of their controllable transmission, absorption and/or reflectance. For instance, a major application of these devices is in smart windows that can regulate the solar gains of buildings and also in glare attenuation in automobile rear view mirrors. Other applications include solar cells, small and large area flat panel displays, satellite temperature control, food monitoring, and document authentication. A typical electrochromic device has a five-layer structure: GS/TC/EC/IC/IS/TC/GS, where GS is a glass substrate, TC is a transparent conductor, generally ITO (indium tin oxide) or FTO (fluorine tin oxide), EC is an electrochromic coating, IC is an ion conductor (solid or liquid electrolyte) and IS is an ion storage coating. Generally, the EC and IS layers are deposited separately on the TC coatings and then jointed with the IC and sealed. The EC and IS are thin films that can be deposited by sputtering, CVD, sol-gel precursors, etc. There are different kinds of organic, inorganic and organic-inorganic films that can be used to make electrochromic devices. Thin electrochromic films can be: WO3, Nb2O5, Nb2O5:Li+ or Nb2O5-TiO2 coatings, ions storage films: CeO2-TiO2, CeO2-ZrO2 or CeO2-TiO2-ZrO2 and electrolytes like Organically Modified Electrolytes (Ormolytes) or polymeric films also based on natural polymers like starch or cellulose. These last are very interesting due to their high ionic conductivity, high transparency and good mechanical properties. This paper describes construction and properties of different thin oxide and polymeric films and also shows the optical response of an all sol-gel electrochromic device with WO3/Ormolyte/CeO2-TiO2 configuration.

  15. Electrochromic projection and writing device

    DOEpatents

    Branz, Howard M.; Benson, David K.

    2002-01-01

    A display and projection apparatus includes an electrochromic material and a photoconductive material deposited in tandem used in conjunction with a light filtering means for filtering light transmitted through the electrochromic material. When an electric field is applied across the electrochromic material and the photoconductive material, light that is incident onto the photoconductive material through the surface of the projection apparatus causes the photoconductive material to conduct current locally in proportion to the amount of light incident on the photoconductive material. The flow of current causes the underlying portions of the electrochromic material to switch from an opaque state to a clear or transmissive state, thereby allowing back-light to propagate through the electrochromic material to create a visible image on the surface of the projection apparatus. Reversal of the electric field causes the electrochromic material to revert back to its opaque state, thereby blocking the transmission of back-light and effectively erasing the image from the surface of the projection apparatus.

  16. Nanocrystal-polymer nanocomposite electrochromic device

    SciTech Connect

    Milliron, Delia; Runnerstrom, Evan; Helms, Brett; Llordes, Anna; Buonsanti, Raffaella; Garcia, Guillermo

    2015-12-08

    Described is an electrochromic nanocomposite film comprising a solid matrix of an oxide based material, the solid matrix comprising a plurality of transparent conducting oxide (TCO) nanostructures dispersed in the solid matrix and a lithium salt dispersed in the solid matrix. Also described is a near infrared nanostructured electrochromic device having a functional layer comprising the electrochromic nanocomposite film.

  17. Reactive Sputter Deposition of WO3/Ag/WO3 Film for Indium Tin Oxide (ITO)-Free Electrochromic Devices.

    PubMed

    Yin, Yi; Lan, Changyong; Guo, Huayang; Li, Chun

    2016-02-17

    Functioning both as electrochromic (EC) and transparent-conductive (TC) coatings, WO3/Ag/WO3 (WAW) trilayer film shows promising potential application for ITO-free electrochromic devices. Reports on thermal-evaporated WAW films revealed that these bifunctional WAW films have distinct EC characteristics; however, their poor adhesive property leads to rapid degradation of coloring-bleaching cycling. Here, we show that WAW film with improved EC durability can be prepared by reactive sputtering using metal targets. We find that, by introducing an ultrathin tungsten (W) sacrificial layer before the deposition of external WO3, the oxidation of silver, which leads to film insulation and apparent optical haze, can be effectively avoided. We also find that the luminous transmittance and sheet resistance were sensitive to the thicknesses of tungsten and silver layers. The optimized structure for TC coating was obtained to be WO3 (45 nm)/Ag (10 nm)/W (2 nm)/WO3 (45 nm) with a sheet resistance of 16.3 Ω/□ and a luminous transmittance of 73.7%. Such film exhibits compelling EC performance with decent luminous transmittance modulation ΔTlum of 29.5%, fast switching time (6.6 s for coloring and 15.9 s for bleaching time), and long-term cycling stability (2000 cycles) with an applied potential of ±1.2 V. Thicker external WO3 layer (45/10/2/100 nm) leads to larger modulation with maximum ΔTlum of 46.4%, but at the cost of significantly increasing the sheet resistance. The strategy of introducing ultrathin metal sacrificial layer to avoid silver oxidation could be extended to fabricating other oxide-Ag-oxide transparent electrodes via low-cost reactive sputtering. PMID:26726834

  18. Graphene based flexible electrochromic devices

    NASA Astrophysics Data System (ADS)

    Polat, Emre O.; Balcı, Osman; Kocabas, Coskun

    2014-10-01

    Graphene emerges as a viable material for optoelectronics because of its broad optical response and gate-tunable properties. For practical applications, however, single layer graphene has performance limits due to its small optical absorption defined by fundamental constants. Here, we demonstrated a new class of flexible electrochromic devices using multilayer graphene (MLG) which simultaneously offers all key requirements for practical applications; high-contrast optical modulation over a broad spectrum, good electrical conductivity and mechanical flexibility. Our method relies on electro-modulation of interband transition of MLG via intercalation of ions into the graphene layers. The electrical and optical characterizations reveal the key features of the intercalation process which yields broadband optical modulation up to 55 per cent in the visible and near-infrared. We illustrate the promises of the method by fabricating reflective/transmissive electrochromic devices and multi-pixel display devices. Simplicity of the device architecture and its compatibility with the roll-to-roll fabrication processes, would find wide range of applications including smart windows and display devices. We anticipate that this work provides a significant step in realization of graphene based optoelectronics.

  19. Graphene based flexible electrochromic devices.

    PubMed

    Polat, Emre O; Balcı, Osman; Kocabas, Coskun

    2014-01-01

    Graphene emerges as a viable material for optoelectronics because of its broad optical response and gate-tunable properties. For practical applications, however, single layer graphene has performance limits due to its small optical absorption defined by fundamental constants. Here, we demonstrated a new class of flexible electrochromic devices using multilayer graphene (MLG) which simultaneously offers all key requirements for practical applications; high-contrast optical modulation over a broad spectrum, good electrical conductivity and mechanical flexibility. Our method relies on electro-modulation of interband transition of MLG via intercalation of ions into the graphene layers. The electrical and optical characterizations reveal the key features of the intercalation process which yields broadband optical modulation up to 55 per cent in the visible and near-infrared. We illustrate the promises of the method by fabricating reflective/transmissive electrochromic devices and multi-pixel display devices. Simplicity of the device architecture and its compatibility with the roll-to-roll fabrication processes, would find wide range of applications including smart windows and display devices. We anticipate that this work provides a significant step in realization of graphene based optoelectronics. PMID:25270391

  20. Self bleaching photoelectrochemical-electrochromic device

    DOEpatents

    Bechinger, Clemens S.; Gregg, Brian A.

    2002-04-09

    A photoelectrochemical-electrochromic device comprising a first transparent electrode and a second transparent electrode in parallel, spaced relation to each other. The first transparent electrode is electrically connected to the second transparent electrode. An electrochromic material is applied to the first transparent electrode and a nanoporous semiconductor film having a dye adsorbed therein is applied to the second transparent electrode. An electrolyte layer contacts the electrochromic material and the nanoporous semiconductor film. The electrolyte layer has a redox couple whereby upon application of light, the nanoporous semiconductor layer dye absorbs the light and the redox couple oxidizes producing an electric field across the device modulating the effective light transmittance through the device.

  1. Electrochromic device using mercaptans and organothiolate compounds

    SciTech Connect

    Lampert, C.M.; Ma, Y.P.; Doeff, M.M.; Visco, S.

    1995-08-15

    An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection. 5 figs.

  2. Electrochromic device using mercaptans and organothiolate compounds

    DOEpatents

    Lampert, Carl M.; Ma, Yan-ping; Doeff, Marca M.; Visco, Steven

    1995-01-01

    An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection.

  3. Electrochromic Salts, Solutions, and Devices

    SciTech Connect

    Burrell, Anthony K.; Warner, Benjamin P.; McClesky, T. Mark

    2008-11-11

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  4. Electrochromic salts, solutions, and devices

    SciTech Connect

    Burrell, Anthony K.; Warner, Benjamin P.; McClesky,7,064,212 T. Mark

    2006-06-20

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  5. Electrochromic Salts, Solutions, and Devices

    SciTech Connect

    Burrell, Anthony K.; Warner, Benjamin P.; McClesky, T. Mark

    2008-10-14

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  6. Photochromic, electrochromic, photoelectrochromic and photovoltaic devices

    DOEpatents

    Kostecki, Robert; McLarnon, Frank R.

    2000-01-01

    A light activated photoelectrochromic device is formed of a two-component system formed of a photoactive charge carrier generating material and electrochromic material (plus an elecrolyte). Light interacts with a semiconductive material to generate hole-electron charge carriers which cause a redox reaction in the electrochromic material. One device is formed of hydrated nickel oxide as the electrochromic layer and polycrystalline titanium dioxide as the charge generating material. The materials may be formed as discrete layers or mixed together. Because of the direct charge transfer between the layers, a circuit to apply a voltage to drive the electrochromic reaction is not required, although one can be used to enhance the reaction. The hydrated nickel oxide-titanium dioxide materials can also be used to form a photovoltaic device for generating electricity.

  7. Electrochromic properties of NiOx:H films deposited by DC magnetron sputtering for ITO/NiOx:H/ZrO2/WO3/ITO device

    NASA Astrophysics Data System (ADS)

    Dong, Dongmei; Wang, Wenwen; Dong, Guobo; Zhou, Yuliang; Wu, Zhonghou; Wang, Mei; Liu, Famin; Diao, Xungang

    2015-12-01

    NiOx:H thin films were deposited on ITO-coated glass by DC reactive magnetron sputtering at room temperature. The effects of the hydrogen content on the structure, morphologies, electrochemical properties, the stoichiometry and chemical states of NiOx:H thin films were systematically studied. In X-ray diffraction and atomic force microscopy analysis, the crystallinity of the films tends to be weakened when the flow amount ratio of Ar:O2:H2 equals 19:1:3 and as confirmed in electrochemical analysis, such relatively weak crystallinity is the main contributing factor to ion transportation. X-ray photoelectron spectroscopy reveals that the increase of the hydrogen contents results in a relatively lower binding energy exhibited in the Ni 2p spectra. The proportion of Ni2O3 in NiOx:H films increases from 22% at bleached state to 33% at colored state. A monolithic all-thin-film inorganic electrochromic device was fabricated with complementary configuration as ITO/NiOx:H/ZrO2/WO3/ITO. The electrochromic device with optimized NiOx:H thin films acting both as ion storage layer and proton-providing source displays high modulation efficiency of 68% at a fixed wavelength 550 nm.

  8. Preparation and characterization of spray deposited n-type WO{sub 3} thin films for electrochromic devices

    SciTech Connect

    Sivakumar, R.; Moses Ezhil Raj, A.; Subramanian, B.; Jayachandran, M.; Trivedi, D.C.; Sanjeeviraja, C

    2004-08-03

    The n-type tungsten oxide (WO{sub 3}) polycrystalline thin films have been prepared at an optimized substrate temperature of 250 deg. C by spray pyrolysis technique. Precursor solution of ammonium tungstate ((NH{sub 4}){sub 2}WO{sub 4}) was sprayed onto the well cleaned, pre-heated fluorine doped tin oxide coated (FTO) and glass substrates with a spray rate of 15 ml/min. The structural, surface morphological and optical properties of the as-deposited WO{sub 3} thin films were studied. Mott-Schottky (M-S) studies of WO{sub 3}/FTO electrodes were conducted in Na{sub 2}SO{sub 4} solution to identify their nature and extract semiconductor parameters. The electrochromic properties of the as-deposited and lithiated WO{sub 3}/FTO thin films were analyzed by employing them as working electrodes in three electrode electrochemical cell using an electrolyte containing LiClO{sub 4} in propylene carbonate (PC) solution.

  9. Large-area flexible monolithic ITO/WO3/Nb2O5/NiVOχ/ITO electrochromic devices prepared by using magnetron sputter deposition

    NASA Astrophysics Data System (ADS)

    Tang, Chien-Jen; Ye, Jia-Ming; Yang, Yueh-Ting; He, Ju-Liang

    2016-05-01

    Electrochromic devices (ECDs) have been applied in smart windows to control the transmission of sunlight in green buildings, saving up to 40-50% electricity consumption and ultimately reducing carbon dioxide emissions. However, the high manufacturing costs and difficulty of transportation of conventional massive large area ECDs has limited widespread applications. A unique design replacing the glass substrate commonly used in the ECD windows with inexpensive, light-weight and flexible polymeric substrate materials would accelerate EC adoption allowing them to be supplemented for regular windows without altering window construction. In this study, an ITO/WO3/Nb2O5/NiVOχ/ITO all-solid-state monolithic ECD with an effective area of 24 cm × 18 cm is successfully integrated on a PET substrate by using magnetron sputter deposition. The electrochromic performance and bending durability of the resultant material are also investigated. The experimental results indicate that the ultimate response times for the prepared ECD is 6 s for coloring at an applied voltage of -3 V and 5 s for bleaching at an applied voltage of +3 V, respectively. The optical transmittances for the bleached and colored state at a wavelength of 633 nm are 53% and 11%, respectively. The prepared ECD can sustain over 8000 repeated coloring and bleaching cycles, as well as tolerate a bending radius of curvature of 7.5 cm.

  10. Electrochromic devices based on lithium insertion

    SciTech Connect

    Richardson, Thomas J.

    2006-05-09

    Electrochromic devices having as an active electrode materials comprising Sb, Bi, Si, Ge, Sn, Te, N, P, As, Ga, In, Al, C, Pb, I and chalcogenides are disclosed. The addition of other metals, i.e. Ag and Cu to the active electrode further enhances performance.

  11. Multicolor Electrochromics: Rainbow-Like Devices.

    PubMed

    Alesanco, Yolanda; Viñuales, Ana; Palenzuela, Jesús; Odriozola, Ibon; Cabañero, Germán; Rodriguez, Javier; Tena-Zaera, Ramón

    2016-06-15

    Stimuli-responsive reversible coloration-change materials represent a highly demanded type of smart systems useful for a wide variety of applications, with a significant growing interest in multicolor abilities. In particular, electrochromic materials have received a great deal of attention due to their versatility and broad range of industrial uses. However, most of the existing electrochromic technologies provide a single coloration, while achieving multiple colors based on simple approaches remains a challenge. The present article reports on PVA gel-based electrochromic devices, containing a single viologen, providing a colorless and two different well-defined colored states. The successful fabrication of a device, based on two viologens (multi-EC gel) with a simple architecture (glass/TCO/multi-EC gel/TCO/glass), with five different multiswitchable colors based on four-zoned electrodes (rainbow-like ECD) is also demonstrated. This novel easy-to-make multichromic system represents a significant breakthrough toward the generation of full-color devices, expanding the potential of electrochromic technology. PMID:27206084

  12. Sol-gel deposited electrochromic films for electrochromic smart window glass

    SciTech Connect

    Oezer, N.; Lampert, C.M.; Rubin, M.

    1996-08-01

    Electrochromic windows offer the ability to dynamically change the transmittance of a glazing. With the appropriate sensor and controls, this smart window can be used for energy regulation and glare control for a variety of glazing applications. The most promising are building and automotive applications. This work covers the use of sol-gel deposition processes to make active films for these windows. The sol-gel process offers a low-capital investment for the deposition of these active films. Sol-gel serves as an alternative to more expensive vacuum deposition processes. The sol-gel process utilizes solution coating followed by a hydrolysis and condensation. In this investigation the authors report on tungsten oxide and nickel oxide films made by the sol-gel process for electrochromic windows. The properties of the sol-gel films compare favorably to those of films made by other techniques. A typical laminated electrochromic window consists of two glass sheets coated with transparent conductors, which are coated with the active films. The two sheets are laminated together with an ionically conductive polymer. The range of visible transmission modulation of the tungsten oxide was 60% and for the nickel oxide was 20%. The authors used the device configuration of glass/SnO{sub 2}:F/W0{sub 3}/polymer/Li{sub Z}NiO{sub x}H{sub y}/SnO{sub 2}:F glass to test the films. The nickel oxide layer had a low level of lithiation and possibly contained a small amount of water. Lithiated oxymethylene-linked poly(ethylene oxide) was used as the laminating polymer. Commercially available SnO{sub 2}:F/glass (LOF-Tec glass) was used as the transparent conducting glass. The authors found reasonable device switching characteristics which could be used for devices.

  13. Low voltage solid-state lateral coloration electrochromic device

    NASA Astrophysics Data System (ADS)

    Tracy, C. E.; Benson, D. K.; Ruth, M. R.

    1984-12-01

    A solid-state transition metal oxide device comprising a plurality of layers having a predisposed orientation including an electrochromic oxide layer. Conductive material including anode and cathode contacts is secured to the device. Coloration is actuated within the electrochromic oxide layer after the application of a predetermined potential between the contacts. The coloration action is adapted to sweep or dynamically extend across the length of the electrochromic oxide layer.

  14. Low voltage solid-state lateral coloration electrochromic device

    SciTech Connect

    Tracy, C. Edwin; Benson, David K.; Ruth, Marta R.

    1987-01-01

    A solid-state transition metal oxide device comprising a plurality of lay having a predisposed orientation including an electrochromic oxide layer. Conductive material including anode and cathode contacts is secured to the device. Coloration is actuated within the electrochromic oxide layer after the application of a predetermined potential between the contacts. The coloration action is adapted to sweep or dynamically extend across the length of the electrochromic oxide layer.

  15. Low voltage solid-state lateral coloration electrochromic device

    SciTech Connect

    Tracy, C.E.; Benson, D.K.; Ruth, M.R.

    1984-12-21

    A solid-state transition metal oxide device comprising a plurality of layers having a predisposed orientation including an electrochromic oxide layer. Conductive material including anode and cathode contacts is secured to the device. Coloration is actuated within the electrochromic oxide layer after the application of a predetermined potential between the contacts. The coloration action is adapted to sweep or dynamically extend across the length of the electrochromic oxide layer.

  16. Electrochromic devices: From windows to fabric

    NASA Astrophysics Data System (ADS)

    Invernale, Michael Anthony

    This dissertation focuses on electrochromic and conducting polymers and devices thereof. Chapter 3: An ion storage layer, poly(thieno[3,4- b]thiophene), was used in the assembly of electrochromic devices (ECDs). Its high-doping level and low-absorption in the visible region in both its oxidized and neutral states makes it an ideal candidate for use as an ion shuttling layer in ECDs. This layer did not distort ECD color, nor does it have a yellowed tint to it (as some previous materials) that may distort vision over time. The characterization of a novel substituted 3,4-propylenedioxythiophene, 1,3-dimethyl (1,3-DM-ProDOT), is also presented. Chapter 4: The precursor polymer method, which imparts solubility and processability to electrochromic precursors, allowed for the preparation of electrochromics inside assembled solid-state devices. The same polymeric material can be made through in situ conversion (oxidation inside an assembled device) as via solution methods (ex situ conversion via electrochemical or chemical oxidation), saving a step in device preparation. Clean substrates were not needed for this method, removing another step in device production. A study of the effects of precursor film thickness, gel electrolyte composition (including the use of ionic liquids), and comparison to traditionally assembled (ex situ) devices is illustrated therein. These precursor polymers have also been ink-jetted, expanding their utility to a large variety of complex electronics. Further, the use of these materials to prepare easily-assembled electrochromic sunglasses is discussed. The in situ method was also extended to using monomers inside of the electrolyte and electropolymerization thereof. This method offers a simpler still method for ECD assembly. This system was studied with respect to higher contrasts and unique patterning abilities, as well as for a variety of chromophores. Chapter 5: A new side-chain based precursor polymer was developed using a single pendant

  17. Graphene as an efficient interfacial layer for electrochromic devices.

    PubMed

    Lin, Feng; Bult, Justin B; Nanayakkara, Sanjini; Dillon, Anne C; Richards, Ryan M; Blackburn, Jeffrey L; Engtrakul, Chaiwat

    2015-06-01

    This study presents an interfacial modification strategy to improve the performance of electrochromic films that were fabricated by a magnetron sputtering technique. High-quality graphene sheets, synthesized by chemical vapor deposition, were used to modify fluorine-doped tin oxide substrates, followed by the deposition of high-performance nanocomposite nickel oxide electrochromic films. Electrochromic cycling results revealed that a near-complete monolayer graphene interfacial layer improves the electrochromic performance in terms of switching kinetics, activation period, coloration efficiency, and bleached-state transparency, while maintaining ∼100% charge reversibility. The present study offers an alternative route for improving the interfacial properties between electrochromic and transparent conducting oxide films without relying on conventional methods such as nanostructuring or thin film composition control. PMID:25950270

  18. Low voltage solid-state lateral coloration electrochromic device

    SciTech Connect

    Tracy, C.E.; Benson, D.K.; Ruth, M.R.

    1987-02-24

    A solid-state transition metal oxide device is described comprising layers including cathode contact means, anode contact means, means including a layer of dielectric material and means including an electrochromic oxide layer. The means is arranged and oriented such that the application of a predetermined potential to the transition metal oxide device is effective for actuating blue coloration within the electrochromic oxide layer and wherein the coloration action sweeps across the length of the electrochromic oxide layer from the cathode contact means to the anode contact means.

  19. Electrochromic material and electro-optical device using same

    DOEpatents

    Cogan, S.F.; Rauh, R.D.

    1992-01-14

    An oxidatively coloring electrochromic layer of composition M[sub y]CrO[sub 2+x] (0.33[le]y[le]2.0 and x[le]2) where M=Li, Na or K with improved transmittance modulation, improved thermal and environmental stability, and improved resistance to degradation in organic liquid and polymeric electrolytes. The M[sub y]CrO[sub 2+x] provides complementary optical modulation to cathodically coloring materials in thin-film electrochromic glazings and electrochromic devices employing polymeric Li[sup +] ion conductors. 12 figs.

  20. Electrochromic material and electro-optical device using same

    DOEpatents

    Cogan, Stuart F.; Rauh, R. David

    1992-01-01

    An oxidatively coloring electrochromic layer of composition M.sub.y CrO.sub.2+x (0.33.ltoreq.y.ltoreq.2.0 and x.ltoreq.2) where M=Li, Na or K with improved transmittance modulation, improved thermal and environmental stability, and improved resistance to degradation in organic liquid and polymeric electrolytes. The M.sub.y CrO.sub.2+x provides complementary optical modulation to cathodically coloring materials in thin-film electrochromic glazings and electrochromic devices employing polymeric Li.sup.+ ion conductors.

  1. Ultrathin W18O49 nanowire assemblies for electrochromic devices.

    PubMed

    Liu, By Jian-Wei; Zheng, Jing; Wang, Jin-Long; Xu, Jie; Li, Hui-Hui; Yu, Shu-Hong

    2013-08-14

    Ordered W18O49 nanowire thin films were fabricated by Langmuir-Blodgett (LB) technique in the presence of poly(vinyl pyrrolidone) coating. The well-organized monolayer of W18O49 nanowires with periodic structures can be readily used as electrochromic sensors, showing reversibly switched electrochromic properties between the negative and positive voltage. Moreover, the electrochromism properties of the W18O49 nanowire films exhibit significant relationship with their thickness. The coloration/bleaching time was around 2 s for the W18O49 nanowire monolayer, which is much faster than the traditional tungsten oxide nanostructures. Moreover, the nanowire devices display excellent stability when color switching continues, which may provide a versatile and promising platform for electrochromism device, smart windows, and other applications. PMID:23869487

  2. Insertion of lithium into electrochromic devices after completion

    SciTech Connect

    Berland, Brian Spencer; Lanning, Bruce Roy; Frey, Jonathan Mack; Barrett, Kathryn Suzanne; DuPont, Paul Damon; Schaller, Ronald William

    2015-12-22

    The present disclosure describes methods of inserting lithium into an electrochromic device after completion. In the disclosed methods, an ideal amount of lithium can be added post-fabrication to maximize or tailor the free lithium ion density of a layer or the coloration range of a device. Embodiments are directed towards a method to insert lithium into the main device layers of an electrochromic device as a post-processing step after the device has been manufactured. In an embodiment, the methods described are designed to maximize the coloration range while compensating for blind charge loss.

  3. Printed Multicolor High-Contrast Electrochromic Devices.

    PubMed

    Chen, Bo-Han; Kao, Sheng-Yuan; Hu, Chih-Wei; Higuchi, Masayoshi; Ho, Kuo-Chuan; Liao, Ying-Chih

    2015-11-18

    In this study, electrochemical responses of inkjet-printed multicolored electrochromic devices (ECD) were studied to evaluate the feasibility of presenting multiple colors in one ECD. Metallo-supramolecular polymers (MEPE) solutions with two primary colors were inkjet-printed on flexible electrodes. By digitally controlling print dosages of each species, the colors of the printed EC thin film patterns can be adjusted directly without premixing or synthesizing new materials. The printed EC thin films were then laminated with a solid transparent thin film electrolyte and a transparent conductive thin film to form an ECD. After applying a dc voltage, the printed ECDs exhibited great contrast with a transmittance change (ΔT) of 40.1% and a high coloration efficiency of 445 cm(2) C(-1) within a short darkening time of 2 s. The flexible ECDs also showed the same darkening time of 2 s and still had a high ΔT of 30.1% under bending condition. This study demonstrated the feasibility to fabricate display devices with different color setups by an all-solution process and can be further extended to other types of displays. PMID:26496422

  4. Materials And Devices In Electrochromic Window Development

    NASA Astrophysics Data System (ADS)

    Cogan, Stuart F.; Anderson, Elizabeth J.; Plante, Timothy D.; Rauh, R. David

    1985-12-01

    Windows with switchable electrochromic glazings are potentially useful for regulating solar input to building interiors. In this article, we describe the structure and operation of a proposed solid-state electrochromic glazing based on crystalline LixWO3 (c-LiXWO3) and a low coloration efficiency counter electrode material such as amorphous Nb2O5 (a-Nb2O5). The importance of reversibility in electrochromic glazing operation is emphasized, and optical switching experiments that demonstrate reversible lithium insertion/extraction in c-LixW03, a-LixWO3, and a-LixNb2O5 are described. Additional optical switching experiments in tandem electrochromic cells comprised of c-LixWO3/a-Nb2O5 and a-LixWO3/a-Nb2O5 demonstrated the proposed design, indicating reversible optical switching over 500 and 200 complete cycles, respectively, without degradation. Optical data on the evolution of reflective and absorp-tive modulation in c-LixWO3 are presented and solar attenuation results are used to demon-strate the advantage of using crystalline electrochromics to conserve daylighting during electrochromic window operation.

  5. An Inexpensive Device for Studying Electrochromism

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Puente-Caballero, Rodrigo; Torres-Perez, Jonatan; Bustos, Daniel; Carmona-Orbezo, Aranzazu; Sevilla, Fortunato B., III

    2012-01-01

    A novel procedure for the preparation of electrochromic WO[subscript 3] films from readily available materials is presented. It is based on the electrochemical preparation of potassium tungstate from tungsten filaments of incandescent light bulbs in a potassium hydroxide solution. Tungstic acid is then produced by proton exchange using a…

  6. Patternable PEDOT nanofilms with grid electrodes for transparent electrochromic devices targeting thermal camouflage

    NASA Astrophysics Data System (ADS)

    Kim, Bumsoo; Koh, Jong Kwan; Park, Junyong; Ahn, Changui; Ahn, Joonmo; Kim, Jong Hak; Jeon, Seokwoo

    2015-10-01

    This paper reports a new type of transmitting mode electrochromic device that uses the high-contrast electrochromism of poly(3,4-ethylenedioxythiophene) (PEDOT) and operates at long-wavelength infrared (8-12 μm) . To maximize the transmittance contrast and transmittance contrast ratio of the device for thermal camouflage, we control the thickness of the thin PEDOT layer from 25 nm to 400 nm and develop a design of grid-type counter electrodes. The cyclability can be greatly improved by selective deposition of the PEDOT film on grid electrodes as an ion storage layer without any loss of overall transmittance. The device with optimized architectures shows a high transmittance contrast ratio of 83 % at a wavelength of 10 μm with a response rate under 1.4 s when alternating voltage is applied. Captured images of an LED lamp behind the device prove the possibility of active, film-type camouflage against thermal detection.

  7. Autonomous electrochromic assembly

    SciTech Connect

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacity state. The electrochromic assembly may be used in combination with a window.

  8. Novel fabrication of an electrochromic antimony-doped tin oxide film using a nanoparticle deposition system

    NASA Astrophysics Data System (ADS)

    Kim, Hyungsub; Park, Yunchan; Choi, Dahyun; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2016-07-01

    Novel deposition method of Antimony-doped tin oxide (ATO) thin films was introduced using a nanoparticle deposition system (NPDS) to fabricate an electrochromic (EC) device. NPDS is a dry deposition method that simplifies the ATO deposition process by eliminating the need for solvents or binders. In this study, an ATO EC layer was deposited using NPDS. The surface morphology and electrochemical and optical transmittance properties were characterized. The optical transmittance change in the ATO EC device was ∼35% over the wavelength range of 350-800 nm, and the cyclic transmittance was stable. The ATO film deposited using NPDS, exhibited a coloration efficiency of 15.5 cm2 C-1. Therefore, our results suggest that ATO EC devices can be fabricated using a simple, cost-effective NPDS, which allows nanoparticles to be deposited directly without pre- or post-processing.

  9. Characterization and performance of WO{sub 3}:Mo/Nafion-H{trademark} electrochromic device

    SciTech Connect

    Pennisi, A.; Simone, F.

    1994-12-31

    Here are presented the results of electrochemical and optical measurements on tungsten trioxide, molybdenum doped (WO{sub 3}:Mo) thin films, electrochemically deposited, assembled with Nafion-H in order to realize an electrochromic (EC) device. The polymer that permits the ionic exchange has a residual viscosity, so that the authors` device cannot be defined as a really solid state device. A good reason for the use of this polymer is its very high proton storage capability, so that, in their devices, it is possible to avoid the presence of a specific ion storage counterelectrode. In this work the authors compare also the electrochromic behavior of devices in dependence on the thermal treatment operated on the electrochemical films after deposition. Analysis has been carried on to reveal morphological characteristics of surface, thickness and stoichiometry of EC compound. Particular attention is paid to the potential waveform used to bias the devices, in order to optimize their performance and to avoid problems of stability and degradation.

  10. Characteristics of laminated electrochromic devices using polyorganodisulfide electrodes

    SciTech Connect

    Lampert, C.M.; Visco, S.J.; Doeff, M.M.; Ma, Y.P.; He, Y.; Giron, J.C.

    1993-12-31

    The use of polyorganodisulfides as optically passive counter-electrodes in a variety of electrochromic devices are discussed. Characteristic data are presented for electrochromic devices using proton, and lithium coloration ions with polyethylene oxide electrolyte and polydimercaptothiadiazole positive electrodes. Solid state devices consisting of molybdenum doped WO{sub 3}, amorphous polyethylene oxide electrolyte (a-PEO), and a polyorganodisulfide counter-electrode colored rapidly from a pale yellow to a deep blue-green, upon application of 1.2 V d.c. The photopic transmittance changed from 61 to 9%, and the solar transmittance from 45 to 5% during the coloration process. Also, the experiments with polyimidazole are detailed. This family of compounds due to its unique electrical and ion conduction properties allow a single composite ion storage and ion conductor electrode to be made, simplifying the device construction. Devices made from this family of compounds color to deep blue-gray upon application of 1.2--1.5 V. Bleaching occurs at {minus}0.4 to {minus}0.5V. The photopic transmittance changed from 55 to 9%, and the solar transmittance from 34 to 4% during coloration. Both coloration and bleaching are quite rapid.

  11. Electrochromic lithium nickel oxide thin film by pulsed laser deposition

    SciTech Connect

    Wen, S.J.; Rottkay, K. von; Rubin, M.

    1996-10-01

    * Thin films of lithium nickel oxide were deposited by pulsed laser deposition (PLD) from targets of pressed LiNiO{sub 2} powder with layered structure. The composition, structure and surface air sensitivity of these films were analyzed using a variety of techniques, such as nuclear reaction analysis, Rutherford backscattering spectrometry (RBS), x-ray diffraction, infrared spectroscopy, and atomic force microscopy. Optical properties were measured using a combination of variable angle spectroscopic ellipsometry and IP spectroradiometry. Crystalline structure, surface morphology and chemical composition of Li{sub x}Ni{sub 1-x}O thin films depend strongly on deposition oxygen pressure, temperature as well as substrate target distance. The films produced at temperatures lower than 600 degrees C spontaneously absorb CO{sub 2} and H{sub 2}O at their surface once they are exposed to the air. The films deposited at 600 degrees C proved to be stable in air over a long period. Even when deposited at room temperature the PLD films are denser and more stable than sputtered films. RBS determined that the best electrochromic films had the stoichiometric composition L{sub 0.5}Ni{sub 0.5}O when deposited at 60 mTorr O{sub 2} pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0 V to 3.4 V versus lithium and long cyclic life stability in a liquid electrolyte half cell. Electrochemical formatting which is used to develop electrochromism in other films and nickel oxide films is not needed for these stoichiometric films. The optical transmission range is almost 70% at 550 nm for 120 nm thick films.

  12. Foil-based TiO2/gel electrolyte/Ni1-xO electrochromic device made of electrochromic pigment coatings.

    PubMed

    Mihelčič, Mohor; Šurca-Vuk, Angela; Vrhovšk, Dejan; Švegl, Franc; Hajzeri, Metka; Orel, Boris

    2014-01-01

    Thin electrochromic coatings were obtained by co-grinding the mTiA particle aggregates (300 nm in size) with open-corner heptaisobutyl trisilanol POSS (T(8) IB(7)(OH)(3) POSS) acting as dispersant. After the addition of titanium tetraisopropoxide (3-5%) the mTiA pigment dispersion was deposited on FTO glass and plastic ITO PET foils and coatings were obtained by thermal treatment at 150 °C. Optical transmittance and luminous haze from 2 to 6% of the coatings were determined from the corresponding UV-Vis spectra. The achieved electrochromic effect was evaluated by electrochemical charging/discharging in 1 M LiClO(4)/PC electrolyte. Results revealed that the colouring/bleaching changes depended on the extent of grinding and the size of the milling zirconia beads, enabling to distinguish between the surface charging of the mTiA grains and the filling and emptying of the anatase density of states. mTiA pigment coatings deposited on plastic foil were used in combination with Ni(1-x)O pigment coatings for construction of foil-based electrochromic device employing novel gel electrolyte with ionic liquid co-solvent. PMID:25286207

  13. Variable Emittance Electrochromic Devices for Satellite Thermal Control

    NASA Astrophysics Data System (ADS)

    Demiryont, Hulya; Shannon, Kenneth C.

    2007-01-01

    An all-solid-state electrochromic device (ECD) was designed for electronic variable emissivity (VE) control. In this paper, a low weight (5g/m2) electrochromic thermal control device, the EclipseVEECD™, is detailed as a viable thermal control system for spacecraft outer surface temperatures. Discussion includes the technology's performance, satellite applications, and preparations for space based testing. This EclipseVEECD™ system comprises substrate/mirror electrode/active element/IR transparent electrode layers. This system tunes and modulates reflection/emittance from 5 μm to 15 μm region. Average reflectance/emittance modulation of the system from the 400 K to 250 K region is about 75%, while at room temperature (9.5 micron) reflectance/emittance is around 90%. Activation voltage of the EclipseVEECD™ is around ±1 Volt. The EclipseVEECD™ can be used as a smart thermal modulator for the thermal control of satellites and spacecraft by monitoring and adjusting the amount of energy emitted from the outer surfaces. The functionality of the EclipseVEECD™ was successfully demonstrated in vacuum using a multi-purpose heat dissipation/absorption test module, the EclipseHEAT™. The EclipseHEAT™ has been successfully flight checked and integrated onto the United States Naval Alchemy MidSTAR satellite, scheduled to launch December 2006.

  14. Electrochromic and photonic devices utilizing polymer colloidal particles

    NASA Astrophysics Data System (ADS)

    Shim, Goo Hwan

    Since polymer colloidal particles have small size and stable surface properties, these materials have characteristics such as the ability to self-assemble, the ease of functionalization, the flexible coupling with other materials, and the formation of the stable dispersion in a liquid that can be beneficial to the fabrication of the electro-optic and photonic devices to enhance the performance. The main objective of this research is the fabrication of electrochromic devices (ECDs) employing the intrinsically conducting polymer (ICP) colloidal particles as electroactive materials and the crystalline colloidal array (CCA)-based photonic devices using polystyrene (PS) colloidal particles as building blocks. The research reported here focuses on: (1) the fabrication of the patterned ECDs through the inkjet printing of the ICP colloidal particles; (2) the fabrication of the reflection-type ECDs employing the polymerized crystalline colloidal array (PCCA) as a reflection mirror; (3) the dynamic tuning of a photoluminescence (PL) dye through the coupling of a PL dye to the CCA. In the first part, polyaniline (PANI)-silica and poly(3,4-ethylenedioxythiophene) (PEDOT)-silica composite particles having a diameter of 200-300 nm were synthesized, then converted to the ICP-ink via solvent exchange. This ICP-ink could be inkjet-printed on various substrates such as ITO-PET film, commercial transparency film, and cotton fabric using a commercial desktop inkjet printer. ECDs could be fabricated employing an inkjet printed PANI-silica or PEDOT-silica layer on an ITO-PET film as an electrochromic layer. These devices exhibit various color changes corresponding to applied potentials between +1V and -1V. In the spectroelectrochemical analysis PANI-based ECD presents up to 50% transmittance contrast ratio and PEDOT-based one shows up to 40% at lambda max. The switching time of the PANI-based device was 30 seconds and that of PEDOT-based ECD was 5 seconds. The PANI-based ECD could be

  15. Chemical bath deposition and characterization of electrochromic thin films of sodium vanadium bronzes

    SciTech Connect

    Najdoski, Metodija; Koleva, Violeta; Demiri, Sani

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We report a new chemical bath method for the deposition of vanadium bronze thin films. Black-Right-Pointing-Pointer The films are phase mixture of NaV{sub 6}O{sub 15} and Na{sub 1.1}V{sub 3}O{sub 7.9} with 10.58% lattice water. Black-Right-Pointing-Pointer The as-deposited vanadium bronze films exhibit two-step electrochromism. Black-Right-Pointing-Pointer They change their yellow-orange color to green and then from green to blue color. Black-Right-Pointing-Pointer The method allows the preparation of films on substrates with low melting point. -- Abstract: Thin yellow-orange films of sodium vanadium oxide bronzes have been prepared from a sodium-vanadium solution (1:1) at 75 Degree-Sign C and pH = 3. The composition, structure and morphology of the films have been studied by XRD, IR spectroscopy, TG and SEM-EDX analyses. It has been established that the prepared films are a phase mixture of hydrated NaV{sub 6}O{sub 15} (predominant component) and Na{sub 1.1}V{sub 3}O{sub 7.9} with total water content of 10.58%. The sodium vanadium bronze thin films exhibit two-step electrochromism followed by color change from yellow-orange to green, and then from green to blue. The cyclic voltammetry measurements on the as-deposited and annealed vanadium bronze films reveal the existence of different oxidation/reduction vanadium sites which make these films suitable for electrochromic devices. The annealing of the films at 400 Degree-Sign C changes the composition, optical and electrochemical properties.

  16. Variable optical attenuator made by using new electrochromic devices

    NASA Astrophysics Data System (ADS)

    Vergaz, Ricardo; Barrios, David; Sanchez-Pena, Jose M.; Vazquez, Carmen; Pozo-Gonzalo, Cristina; Mecerreyes, David; Pomposo, Jose

    2005-07-01

    Electrochromic (EC) materials are used mainly for domotic applications, such as transparency controlled windows or rear-view mirrors in cars. The device construction is a sandwich of electrochemical compounds, which change their optical properties when applying voltage. Although the changes that are used in the applications take place in the visible, there are also changes in the near infrared region. In the last years, some works have proposed their use in fiber optic applications, mainly as optical modulators or VOAs (Variable Optical Attenuator). EC devices have usually slow responses (several seconds) and low transmittance range, specially the organic ones. The slow response is the major drawback for their use as modulators. But in NIR transmittance ranges, there are promising results in materials like ruthenium or PEDOT (poly(3,4-ethylenedioxythiophene)). In this work, we will study the possible use in VOAs of new EC devices developed with the minimum number of layers, by their response in telecommunications wavelengths. These devices are manufactured in such a way that the integration in fiber optic devices is an easy task. The minimum number of layers and the easy construction are improvements over the existing possibilities. PEDOT is the EC material on these devices, and different manufacturing ways are compared in order to detect the best possible candidate to use.

  17. Multi-layer electrode for high contrast electrochromic devices

    SciTech Connect

    Schwendeman, Irina G.; Finley, James J.; Polcyn, Adam D.; Boykin, Cheri M.

    2011-11-01

    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.

  18. Thin film lithium-based batteries and electrochromic devices fabricated with nanocomposite electrode materials

    DOEpatents

    Gillaspie, Dane T; Lee, Se-Hee; Tracy, C. Edwin; Pitts, John Roland

    2014-02-04

    Thin-film lithium-based batteries and electrochromic devices (10) are fabricated with positive electrodes (12) comprising a nanocomposite material composed of lithiated metal oxide nanoparticles (40) dispersed in a matrix composed of lithium tungsten oxide.

  19. Electrochromic-photovoltaic film for light-sensitive control of optical transmittance

    DOEpatents

    Branz, H.M.; Crandall, R.S.; Tracy, C.E.

    1994-12-27

    A variable transmittance optical component includes an electrochromic material and a photovoltaic device-type thin film solar cell deposited in a tandem type, monolithic single coating over the component. A bleed resistor of a predetermined value is connected in series across the electrochromic material and photovoltaic device controlling the activation and deactivation of the electrochromic material. The electrical conductivity between the electrochromic material and the photovoltaic device is enhanced by interposing a transparent electrically conductive layer. 5 figures.

  20. Electrochromic-photovoltaic film for light-sensitive control of optical transmittance

    DOEpatents

    Branz, Howard M.; Crandall, Richard S.; Tracy, C. Edwin

    1994-01-01

    A variable transmittance optical component includes an electrochromic material and a photovoltaic device-type thin film solar cell deposited in a tandem type, monolithic single coating over the component. A bleed resistor of a predetermined value is connected in series across the electrochromic material and photovoltaic device controlling the activation and deactivation of the electrochromic material. The electrical conductivity between the electrochromic material and the photovoltaic device is enhanced by interposing a transparent electrically conductive layer.

  1. Toward Plastic Smart Windows: Optimization of Indium Tin Oxide Electrodes for the Synthesis of Electrochromic Devices on Polycarbonate Substrates.

    PubMed

    Laurenti, Marco; Bianco, Stefano; Castellino, Micaela; Garino, Nadia; Virga, Alessandro; Pirri, Candido F; Mandracci, Pietro

    2016-03-01

    Plastic smart windows are becoming one of the key elements in view of the fabrication of inexpensive, lightweight electrochromic (EC) devices to be integrated in the new generation of high-energy-efficiency buildings and automotive applications. However, fabricating electrochromic devices on polymer substrates requires a reduction of process temperature, so in this work we focus on the development of a completely room-temperature deposition process aimed at the preparation of ITO-coated polycarbonate (PC) structures acting as transparent and conductive plastic supports. Without providing any substrate heating or surface activation pretreatments of the polymer, different deposition conditions are used for growing indium tin oxide (ITO) thin films by the radiofrequency magnetron sputtering technique. According to the characterization results, the set of optimal deposition parameters is selected to deposit ITO electrodes having high optical transmittance in the visible range (∼90%) together with low sheet resistance (∼8 ohm/sq). The as-prepared ITO/PC structures are then successfully tested as conductive supports for the fabrication of plastic smart windows. To this purpose, tungsten trioxide thin films are deposited by the reactive sputtering technique on the ITO/PC structures, and the resulting single electrode EC devices are characterized by chronoamperometric experiments and cyclic voltammetry. The fast switching response between colored and bleached states, together with the stability and reversibility of their electrochromic behavior after several cycling tests, are considered to be representative of the high quality of the EC film but especially of the ITO electrode. Indeed, even if no adhesion promoters, additional surface activation pretreatments, or substrate heating were used to promote the mechanical adhesion among the electrode and the PC surface, the observed EC response confirmed that the developed materials can be successfully employed for the

  2. Toward Plastic Smart Windows: Optimization of Indium Tin Oxide Electrodes for the Synthesis of Electrochromic Devices on Polycarbonate Substrates.

    PubMed

    Laurenti, Marco; Bianco, Stefano; Castellino, Micaela; Garino, Nadia; Virga, Alessandro; Pirri, Candido F; Mandracci, Pietro

    2016-03-01

    Plastic smart windows are becoming one of the key elements in view of the fabrication of inexpensive, lightweight electrochromic (EC) devices to be integrated in the new generation of high-energy-efficiency buildings and automotive applications. However, fabricating electrochromic devices on polymer substrates requires a reduction of process temperature, so in this work we focus on the development of a completely room-temperature deposition process aimed at the preparation of ITO-coated polycarbonate (PC) structures acting as transparent and conductive plastic supports. Without providing any substrate heating or surface activation pretreatments of the polymer, different deposition conditions are used for growing indium tin oxide (ITO) thin films by the radiofrequency magnetron sputtering technique. According to the characterization results, the set of optimal deposition parameters is selected to deposit ITO electrodes having high optical transmittance in the visible range (∼90%) together with low sheet resistance (∼8 ohm/sq). The as-prepared ITO/PC structures are then successfully tested as conductive supports for the fabrication of plastic smart windows. To this purpose, tungsten trioxide thin films are deposited by the reactive sputtering technique on the ITO/PC structures, and the resulting single electrode EC devices are characterized by chronoamperometric experiments and cyclic voltammetry. The fast switching response between colored and bleached states, together with the stability and reversibility of their electrochromic behavior after several cycling tests, are considered to be representative of the high quality of the EC film but especially of the ITO electrode. Indeed, even if no adhesion promoters, additional surface activation pretreatments, or substrate heating were used to promote the mechanical adhesion among the electrode and the PC surface, the observed EC response confirmed that the developed materials can be successfully employed for the

  3. Ultrafast switching of an electrochromic device based on layered double hydroxide/Prussian blue multilayered films

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoxi; Zhou, Awu; Dou, Yibo; Pan, Ting; Shao, Mingfei; Han, Jingbin; Wei, Min

    2015-10-01

    Electrochromic materials are the most important and essential components in an electrochromic device. Herein, we fabricated high-performance electrochromic films based on exfoliated layered double hydroxide (LDH) nanosheets and Prussian blue (PB) nanoparticles via the layer-by-layer assembly technique. X-ray diffraction and UV-vis absorption spectroscopy indicate a periodic layered structure with uniform and regular growth of (LDH/PB)n ultrathin films (UTFs). The resulting (LDH/PB)n UTF electrodes exhibit electrochromic behavior arising from the reversible K+ ion migration into/out of the PB lattice, which induces a change in the optical properties of the UTFs. Furthermore, an electrochromic device (ECD) based on the (LDH/PB)n-ITO/0.1 M KCl electrolyte/ITO sandwich structure displays superior response properties (0.91/1.21 s for coloration/bleaching), a comparable coloration efficiency (68 cm2 C-1) and satisfactory optical contrast (45% at 700 nm), in comparison with other inorganic material-based ECDs reported previously. Therefore, this work presents a facile and cost-effective strategy to immobilize electrochemically active nanoparticles in a 2D inorganic matrix for potential application in displays, smart windows and optoelectronic devices.Electrochromic materials are the most important and essential components in an electrochromic device. Herein, we fabricated high-performance electrochromic films based on exfoliated layered double hydroxide (LDH) nanosheets and Prussian blue (PB) nanoparticles via the layer-by-layer assembly technique. X-ray diffraction and UV-vis absorption spectroscopy indicate a periodic layered structure with uniform and regular growth of (LDH/PB)n ultrathin films (UTFs). The resulting (LDH/PB)n UTF electrodes exhibit electrochromic behavior arising from the reversible K+ ion migration into/out of the PB lattice, which induces a change in the optical properties of the UTFs. Furthermore, an electrochromic device (ECD) based on the (LDH

  4. BIPV-Powered Smart Windows Utilizing Photovoltaic and Electrochromic Devices

    PubMed Central

    Ma, Rong-Hua; Chen, Yu-Chia

    2012-01-01

    A BIPV-powered smart window comprising a building-integrated photovoltaic (BIPV) panel and an all-solid-state electrochromic (EC) stack is proposed. In the proposed device, the output voltage of the BIPV panel varies in accordance with the intensity of the incident light and is modulated in such a way as to generate the EC stack voltage required to maintain the indoor illuminance within a specified range. Two different EC stacks are fabricated and characterized, namely one stack comprising ITO/WO3/Ta2O5/ITO and one stack comprising ITO/WO3/lithium-polymer electrolyte/ITO. It is shown that of the two stacks, the ITO/WO3/lithium-polymer electrolyte/ITO stack has a larger absorptance (i.e., approximately 99% at a driving voltage of 3.5 V). The experimental results show that the smart window incorporating an ITO/WO3/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750–1,500 Lux under typical summertime conditions in Taiwan. PMID:22368474

  5. Effect of deposition charges on the wettability performance of electrochromic polymers

    NASA Astrophysics Data System (ADS)

    Çağlar, Aysel; Cengiz, Uğur; Yıldırım, Mehmet; Kaya, İsmet

    2015-03-01

    Electrochromic polymers have been designed as future candidates for electrochromic displays (ECDs) and smart windows. This class of conducting polymers has been studied with their several optical properties as well as spectroelectrochemical stabilities. In practical use their contamination and abrasion could be expected to be main problem as exposed to moisture and other possible pollutants. In this study, we present a perspective to well-known electrochromic polymers in the words of their durable use. For this aim, a series of electrochromic polymers are deposited on indium tin oxide (ITO) coated glass plates by bulk electrolysis. Polymeric films are deposited by varied deposition charges (Qs) ranging from 62 to 620 mC cm-2 for comparison. Equilibrium water contact angle (θwaterequ) measurements of the prepared surfaces are measured by Attention Theta Optical Tensiometer. Surface roughness parameters (RMS) are determined by atomic force microscopy (AFM) technique and used for interpretation of hydrophobic-hydrophilic characteristics. The results clearly indicate that; poly(ethylenedioxythiophene) (PEDOT) has a hydrophilic surface whose hydrophilicity is increased by applied deposition charge and becomes a superhydrophile at high deposition charges. Among the tested polymers polycarbazole (PCarb) is the most promising long lifetime candidate due to its relatively hydrophobic character. Also, the hydrophobicity of PCarb is linearly increased by increasing deposition charge and reaches an optimum point at a particular condition.

  6. Inkjet-printed all solid-state electrochromic devices based on NiO/WO3 nanoparticle complementary electrodes

    NASA Astrophysics Data System (ADS)

    Cai, Guofa; Darmawan, Peter; Cui, Mengqi; Chen, Jingwei; Wang, Xu; Eh, Alice Lee-Sie; Magdassi, Shlomo; Lee, Pooi See

    2015-12-01

    Nanostructured thin films are important in the fields of energy conversion and storage. In particular, multi-layered nanostructured films play an important role as a part of the energy system for energy saving applications in buildings. Inkjet printing is a low-cost and attractive technology for patterning and deposition of multi-layered nanostructured materials on various substrates. However, it requires the development of a suitable ink formulation with optimum viscosity, surface tension and evaporation rate for various materials. In this study, a versatile ink formulation was successfully developed to prepare NiO and WO3 nanostructured films with strong adhesion to ITO coated glass using inkjet printing for energy saving electrochromic applications. We achieved a high performance electrochromic electrode, producing porous and continuous electrochromic films without aggregation. The NiO film with 9 printed layers exhibits an optical modulation of 64.2% at 550 nm and a coloration efficiency (CE) of 136.7 cm2 C-1. An inkjet-printed complementary all solid-state device was assembled, delivering a larger optical modulation of 75.4% at 633 nm and a higher CE of 131.9 cm2 C-1 among all solid-state devices. The enhanced contrast is due to the printed NiO film that not only performs as an ion storage layer, but also as a complementary electrochromic layer.Nanostructured thin films are important in the fields of energy conversion and storage. In particular, multi-layered nanostructured films play an important role as a part of the energy system for energy saving applications in buildings. Inkjet printing is a low-cost and attractive technology for patterning and deposition of multi-layered nanostructured materials on various substrates. However, it requires the development of a suitable ink formulation with optimum viscosity, surface tension and evaporation rate for various materials. In this study, a versatile ink formulation was successfully developed to prepare NiO and

  7. Ultrafast switching of an electrochromic device based on layered double hydroxide/Prussian blue multilayered films.

    PubMed

    Liu, Xiaoxi; Zhou, Awu; Dou, Yibo; Pan, Ting; Shao, Mingfei; Han, Jingbin; Wei, Min

    2015-10-28

    Electrochromic materials are the most important and essential components in an electrochromic device. Herein, we fabricated high-performance electrochromic films based on exfoliated layered double hydroxide (LDH) nanosheets and Prussian blue (PB) nanoparticles via the layer-by-layer assembly technique. X-ray diffraction and UV-vis absorption spectroscopy indicate a periodic layered structure with uniform and regular growth of (LDH/PB)n ultrathin films (UTFs). The resulting (LDH/PB)n UTF electrodes exhibit electrochromic behavior arising from the reversible K(+) ion migration into/out of the PB lattice, which induces a change in the optical properties of the UTFs. Furthermore, an electrochromic device (ECD) based on the (LDH/PB)n-ITO/0.1 M KCl electrolyte/ITO sandwich structure displays superior response properties (0.91/1.21 s for coloration/bleaching), a comparable coloration efficiency (68 cm(2) C(-1)) and satisfactory optical contrast (45% at 700 nm), in comparison with other inorganic material-based ECDs reported previously. Therefore, this work presents a facile and cost-effective strategy to immobilize electrochemically active nanoparticles in a 2D inorganic matrix for potential application in displays, smart windows and optoelectronic devices. PMID:26420230

  8. Electrodeposited Films from Aqueous Tungstic Acid-Hydrogen Peroxide Solutions for Electrochromic Display Devices

    NASA Astrophysics Data System (ADS)

    Yamanaka, Kazusuke

    1987-11-01

    Electrodeposited tungsten oxide films from aqueous tungstic acid-hydrogen peroxide solutions were investigated for applications to electrochromic devices. These films exhibited electrochromism in aprotic electrolyte solutions containing Li-salts. When the films were heat-treated for an hour at temperatures between 100 and 200°C, the electrochromic reactions were rich in reversibility. The coloring efficiency and response rate for the films were favorable and comparable to those for tungsten trioxide evaporated films. A cell life-test was performed on several clock-size cells by applying a 1.2-V, 1-Hz, continuous square wave. The typical amount of charge required for coloration was about 50 C / m2 and remained unchanged even after 107 coloration-bleaching cycles.

  9. Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows

    SciTech Connect

    Anders, Andre; Slack, Jonathan L.; Richardson, Thomas J.

    2008-05-05

    Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer and the Pd catalyst. Addition of 9 percent silver to the palladium catalyst further improved system durability. About 100 full cycles have been demonstrated before devices slow considerably. Degradation of device performance appears to be related to Pd catalyst mobility, rather than delamination or metal layer oxidation issues originally presumed likely to present significant challenges.

  10. Electrochromic properties of molybdenum trioxide thin films prepared by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Maruyama, Toshiro; Kanagawa, Tetsuya

    1995-05-01

    Electrochromic molybdenum trioxide thin films were prepared by chemical vapor deposition. The source material was molybdenum carbonyl. Amorphous molybdenum trioxide thin films were produced at a substrate temperature 300 C. Reduction and oxidation of the films in a 0.3M LiClO4 propylene carbon ate solution caused desirable changes in optical absorption. Coulometry indicated that the coloration efficiency was 25.8 sq cm center-dot C(exp -1).

  11. Equipment-Free Deposition of Graphene-Based Molybdenum Oxide Nanohybrid Langmuir-Blodgett Films for Flexible Electrochromic Panel Application.

    PubMed

    Zhang, Haojie; Jeon, Ki-Wan; Seo, Dong-Kyun

    2016-08-24

    The potential electrochromic application of graphene-based nanohybrids is hampered by the challenges in interfacing the electrochromic nanoparticles with graphene at atomic scale and in fabricating their thin film on the substrate through a scalable method. In an effort to overcome these challenges, we demonstrate a highly dispersible graphene-based molybdenum oxide nanohybrid (mRGO-MoO3-x) for flexible electrochromic application. With only a squeeze pipet, mRGO-MoO3-x could be deposited with a high coverage on various substrates through a scalable equipment-free Langmuir-Blodgett film deposition method. By taking advantage of high transmittance benefited from its remarkable thinness, the mRGO-MoO3-x Langmuir-Blodgett film shows a superior reversible electrochromic property with high coloration efficiency on both hard and flexible substrates. PMID:27482604

  12. Equipment-Free Deposition of Graphene-Based Molybdenum Oxide Nanohybrid Langmuir-Blodgett Films for Flexible Electrochromic Panel Application.

    PubMed

    Zhang, Haojie; Jeon, Ki-Wan; Seo, Dong-Kyun

    2016-08-24

    The potential electrochromic application of graphene-based nanohybrids is hampered by the challenges in interfacing the electrochromic nanoparticles with graphene at atomic scale and in fabricating their thin film on the substrate through a scalable method. In an effort to overcome these challenges, we demonstrate a highly dispersible graphene-based molybdenum oxide nanohybrid (mRGO-MoO3-x) for flexible electrochromic application. With only a squeeze pipet, mRGO-MoO3-x could be deposited with a high coverage on various substrates through a scalable equipment-free Langmuir-Blodgett film deposition method. By taking advantage of high transmittance benefited from its remarkable thinness, the mRGO-MoO3-x Langmuir-Blodgett film shows a superior reversible electrochromic property with high coloration efficiency on both hard and flexible substrates.

  13. Characterization of indium oxide for the use as a counter-electrode in an electrochromic device

    SciTech Connect

    Yu, P.C.; Haas, T.E. . Dept. of Chemistry); Goldner, R.B. . Electro-Optics Technology Center); Cogan, S.F. )

    1991-01-01

    Thin films of indium oxide, In{sub 2}O{sub 3} (4000 {Angstrom}), deposited on commercially available In{sub 2}O{sub 3}: Sn (ITO)/glass by rf sputtering, have been examined for potential application as a counter-electrode material in an electrochromic device, based on their chemical, structural, and optical properties. Cyclic voltammetry experiments showed that mobile lithium ions can be inserted (chemical reduction) and removed (chemical oxidation) from the host structure of indium oxide. Coulometric titrations showed that the films exhibited a hysteresis behavior for the injection and removal of lithium ions in Li{sub x}In{sub 2}O{sub 3} (x=0-0.23). Structural investigations of the indium oxide films, utilizing electron diffraction techniques, indicated that they were crystalline with a crystallite size of 175 {Angstrom}, in agreement with x-ray diffraction results. Differences in optical transmission between the lithiated and delithiated thin films were no more than 5% in the visible/near-infrared regions of the spectrum. 6 refs., 5 figs., 1 tab.

  14. Electrochromic properties of spray deposited TiO 2-doped WO 3 thin films

    NASA Astrophysics Data System (ADS)

    Patil, P. S.; Mujawar, S. H.; Inamdar, A. I.; Sadale, S. B.

    2005-08-01

    TiO 2-doped WO 3 thin films were deposited onto fluorine-doped tin oxide coated conducting glass substrates using spray pyrolysis technique at 525 °C. The volume percentage of TiO 2 dopant was varied from 13% to 38%. The thin film samples were transparent, uniform and strongly adherent to the substrates. Electrochromical properties of TiO 2-doped WO 3 thin films were studied with the help of cyclic voltammetry (CV), chronoamperometry (CA) and chronocoulometry (CC) techniques. It has been found that TiO 2 doping in WO 3 enhances its electrochromic performance. Colouration efficiency becomes almost double and samples exhibit increasingly high reversibility with TiO 2 doping concentrations, in the studied range.

  15. Self-Stacked Reduced Graphene Oxide Nanosheets Coated with Cobalt-Nickel Hydroxide by One-Step Electrochemical Deposition toward Flexible Electrochromic Supercapacitors.

    PubMed

    Grote, Fabian; Yu, Zi-You; Wang, Jin-Long; Yu, Shu-Hong; Lei, Yong

    2015-09-01

    The implementation of an optical function into supercapacitors is an innovative approach to make energy storage devices smarter and to meet the requirements of smart electronics. Here, it is reported for the first time that nickel-cobalt hydroxide on reduced graphene oxide can be utilized for flexible electrochromic supercapacitors. A new and straightforward one-step electrochemical deposition process is introduced that is capable of simultaneously reducing GO and depositing amorphous Co(1-x)Ni(x)(OH)2 on the rGO. It is shown that the rGO nanosheets are homogeneously coated with metal hydroxide and are vertically stacked. No high temperature processes are used so that flexible polymer-based substrates can be coated. The synthesized self-stacked rGO-Co(1-x)Ni(x)(OH)2 nanosheet material exhibits pseudocapacitive charge storage behavior with excellent rate capability, high Columbic efficiency, and nondiffusion limited behavior. It is shown that the electrochemical behavior of the Ni(OH)2 can be modulated, by simultaneously depositing nickel and cobalt hydroxide, into broad oxidization and reduction bands. Further, the material exhibits electrochromic property and can switch between a bleached and transparent state. Literature comparison reveals that the performance characteristics of the rGO-Co(1-x)Ni(x)(OH)2 nanosheet material, in terms of gravimetric capacitance, areal capacitance, and long-term cycling stability, are among the highest reported values of supercapacitors with electrochromic property.

  16. Anodically Electrodeposited Iridium Oxide Films (AEIROF) from Alkaline Solutions for Electrochromic Display Devices

    NASA Astrophysics Data System (ADS)

    Yamanaka, Kazusuke

    1989-04-01

    Anodically electrodeposited iridium oxide films from alkaline solutions were investigated for application to electrochromic devices. Micro-crystalline (diameter: 15Å) films obtained by the electrolysis of aqueous alkaline solutions containing iridium chloride, oxalic acid and potassium carbonate showed good electrochromic reaction reversibility. The coloration efficiency of the films was about one third that of typical evaporated tungsten oxide films, and the response rate measured by the amount of injected charge was about double. The cycle lives of the cells, composed of electrodeposited films, 1M H3PO4-NaOH (pH{=}3˜ 5), and an activated carbon cloth, were more than 8× 106 with a 0.6 V, 1 Hz continuous square wave.

  17. A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications.

    PubMed

    Wang, Jinmin; Zhang, Lei; Yu, Le; Jiao, Zhihui; Xie, Huaqing; Lou, Xiong Wen David; Sun, Xiao Wei

    2014-09-23

    Electrochromic smart windows are regarded as a good choice for green buildings. However, conventional devices need external biases to operate, which causes additional energy consumption. Here we report a self-powered electrochromic window, which can be used as a self-rechargeable battery. We use aluminium to reduce Prussian blue (PB, blue in colour) to Prussian white (PW, colourless) in potassium chloride electrolyte, realizing a device capable of self-bleaching. Interestingly, the device can be self-recovered (gaining blue appearance again) by simply disconnecting the aluminium and PB electrodes, which is due to the spontaneous oxidation of PW to PB by the dissolved oxygen in aqueous solution. The self-operated bleaching and colouration suggest another important function of the device: a self-rechargeable transparent battery. Thus the PB/aluminium device we report here is bifunctional, that is, it is a self-powered electrochromic window as well as a self-rechargeable transparent battery.

  18. A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications.

    PubMed

    Wang, Jinmin; Zhang, Lei; Yu, Le; Jiao, Zhihui; Xie, Huaqing; Lou, Xiong Wen David; Sun, Xiao Wei

    2014-01-01

    Electrochromic smart windows are regarded as a good choice for green buildings. However, conventional devices need external biases to operate, which causes additional energy consumption. Here we report a self-powered electrochromic window, which can be used as a self-rechargeable battery. We use aluminium to reduce Prussian blue (PB, blue in colour) to Prussian white (PW, colourless) in potassium chloride electrolyte, realizing a device capable of self-bleaching. Interestingly, the device can be self-recovered (gaining blue appearance again) by simply disconnecting the aluminium and PB electrodes, which is due to the spontaneous oxidation of PW to PB by the dissolved oxygen in aqueous solution. The self-operated bleaching and colouration suggest another important function of the device: a self-rechargeable transparent battery. Thus the PB/aluminium device we report here is bifunctional, that is, it is a self-powered electrochromic window as well as a self-rechargeable transparent battery. PMID:25247385

  19. A transparent electrochromic metal-insulator switching device with three-terminal transistor geometry.

    PubMed

    Katase, Takayoshi; Onozato, Takaki; Hirono, Misako; Mizuno, Taku; Ohta, Hiromichi

    2016-01-01

    Proton and hydroxyl ion play an essential role for tuning functionality of oxides because their electronic state can be controlled by modifying oxygen off-stoichiometry and/or protonation. Tungsten trioxide (WO3), a well-known electrochromic (EC) material for smart window, is a wide bandgap insulator, whereas it becomes a metallic conductor HxWO3 by protonation. Although one can utilize electrochromism together with metal-insulator (MI) switching for one device, such EC-MI switching cannot be utilized in current EC devices because of their two-terminal structure with parallel-plate configuration. Here we demonstrate a transparent EC-MI switchable device with three-terminal TFT-type structure using amorphous (a-) WO3 channel layer, which was fabricated on glass substrate at room temperature. We used water-infiltrated nano-porous glass, CAN (calcium aluminate with nano-pores), as a liquid-leakage-free solid gate insulator. At virgin state, the device was fully transparent in the visible-light region. For positive gate voltage, the active channel became dark blue, and electrical resistivity of the a-WO3 layer drastically decreased with protonation. For negative gate voltage, deprotonation occurred and the active channel returned to transparent insulator. Good cycleability of the present transparent EC-MI switching device would have potential for the development of advanced smart windows.

  20. A transparent electrochromic metal-insulator switching device with three-terminal transistor geometry.

    PubMed

    Katase, Takayoshi; Onozato, Takaki; Hirono, Misako; Mizuno, Taku; Ohta, Hiromichi

    2016-01-01

    Proton and hydroxyl ion play an essential role for tuning functionality of oxides because their electronic state can be controlled by modifying oxygen off-stoichiometry and/or protonation. Tungsten trioxide (WO3), a well-known electrochromic (EC) material for smart window, is a wide bandgap insulator, whereas it becomes a metallic conductor HxWO3 by protonation. Although one can utilize electrochromism together with metal-insulator (MI) switching for one device, such EC-MI switching cannot be utilized in current EC devices because of their two-terminal structure with parallel-plate configuration. Here we demonstrate a transparent EC-MI switchable device with three-terminal TFT-type structure using amorphous (a-) WO3 channel layer, which was fabricated on glass substrate at room temperature. We used water-infiltrated nano-porous glass, CAN (calcium aluminate with nano-pores), as a liquid-leakage-free solid gate insulator. At virgin state, the device was fully transparent in the visible-light region. For positive gate voltage, the active channel became dark blue, and electrical resistivity of the a-WO3 layer drastically decreased with protonation. For negative gate voltage, deprotonation occurred and the active channel returned to transparent insulator. Good cycleability of the present transparent EC-MI switching device would have potential for the development of advanced smart windows. PMID:27174791

  1. A transparent electrochromic metal-insulator switching device with three-terminal transistor geometry

    PubMed Central

    Katase, Takayoshi; Onozato, Takaki; Hirono, Misako; Mizuno, Taku; Ohta, Hiromichi

    2016-01-01

    Proton and hydroxyl ion play an essential role for tuning functionality of oxides because their electronic state can be controlled by modifying oxygen off-stoichiometry and/or protonation. Tungsten trioxide (WO3), a well-known electrochromic (EC) material for smart window, is a wide bandgap insulator, whereas it becomes a metallic conductor HxWO3 by protonation. Although one can utilize electrochromism together with metal-insulator (MI) switching for one device, such EC-MI switching cannot be utilized in current EC devices because of their two-terminal structure with parallel-plate configuration. Here we demonstrate a transparent EC-MI switchable device with three-terminal TFT-type structure using amorphous (a-) WO3 channel layer, which was fabricated on glass substrate at room temperature. We used water-infiltrated nano-porous glass, CAN (calcium aluminate with nano-pores), as a liquid-leakage-free solid gate insulator. At virgin state, the device was fully transparent in the visible-light region. For positive gate voltage, the active channel became dark blue, and electrical resistivity of the a-WO3 layer drastically decreased with protonation. For negative gate voltage, deprotonation occurred and the active channel returned to transparent insulator. Good cycleability of the present transparent EC-MI switching device would have potential for the development of advanced smart windows. PMID:27174791

  2. A transparent electrochromic metal-insulator switching device with three-terminal transistor geometry

    NASA Astrophysics Data System (ADS)

    Katase, Takayoshi; Onozato, Takaki; Hirono, Misako; Mizuno, Taku; Ohta, Hiromichi

    2016-05-01

    Proton and hydroxyl ion play an essential role for tuning functionality of oxides because their electronic state can be controlled by modifying oxygen off-stoichiometry and/or protonation. Tungsten trioxide (WO3), a well-known electrochromic (EC) material for smart window, is a wide bandgap insulator, whereas it becomes a metallic conductor HxWO3 by protonation. Although one can utilize electrochromism together with metal-insulator (MI) switching for one device, such EC-MI switching cannot be utilized in current EC devices because of their two-terminal structure with parallel-plate configuration. Here we demonstrate a transparent EC-MI switchable device with three-terminal TFT-type structure using amorphous (a-) WO3 channel layer, which was fabricated on glass substrate at room temperature. We used water-infiltrated nano-porous glass, CAN (calcium aluminate with nano-pores), as a liquid-leakage-free solid gate insulator. At virgin state, the device was fully transparent in the visible-light region. For positive gate voltage, the active channel became dark blue, and electrical resistivity of the a-WO3 layer drastically decreased with protonation. For negative gate voltage, deprotonation occurred and the active channel returned to transparent insulator. Good cycleability of the present transparent EC-MI switching device would have potential for the development of advanced smart windows.

  3. Electrochromic characteristics of niobium-doped titanium oxide film on indium tin oxide/glass by liquid phase deposition

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Kwei; Lee, Chia-Jung

    2015-10-01

    Ammonium hexafluorotitanate and boric acid aqueous solutions were used as precursors for the growth of titanium oxide films on indium tin oxide (ITO)/glass substrate. For as-grown titanium oxide film used in an electrochromic device, Li+ ions from electrolyte will be trapped to hydroxyl groups and degrade the electrochromic durability during the cyclic voltammogram characterization. For niobium doped titanium oxide film, lower growth rate from more HF incorporation from the niobium doped solution and rougher surface morphology from the formation of nanocrystals were obtained. However, niobium doping reduces hydroxyl groups and the electrochromic durability is enhanced from 5 × 103 to 1 × 104 times. The transmittance is enhanced from 37 to 51% at the wavelength of 550 nm.

  4. Fast Electrochromic Device Based on Single-Walled Carbon Nanotube Thin Films.

    PubMed

    Moser, Matthew L; Li, Guanghui; Chen, Mingguang; Bekyarova, Elena; Itkis, Mikhail E; Haddon, Robert C

    2016-09-14

    Optical properties of electrochromic materials can be controlled by the application of an electric field allowing recent development of new applications such as smart windows technology for indoor climate control and energy conservation. We report the fabrication of a single-walled nanotube (SWNT) thin film based electro-optical modulator controlled by ionic liquid polarization in which the active electrochromic layer is made of a film of semiconducting (SC-) SWNTs and the counter-electrode is composed of a film of metallic (MT-) SWNTs. Optimization of this electro-optical cell allows the operations with an optical modulation depth of 3.7 dB and a response time in the millisecond range, which is thousands of times faster than typical electrolyte-controlled devices. In addition, a dual electro-optical device was built utilizing electro-optically active SC-SWNT films for each electrode that allowed increasing modulation depth of 6.7 dB while preserving the speed of the response.

  5. Fast Electrochromic Device Based on Single-Walled Carbon Nanotube Thin Films.

    PubMed

    Moser, Matthew L; Li, Guanghui; Chen, Mingguang; Bekyarova, Elena; Itkis, Mikhail E; Haddon, Robert C

    2016-09-14

    Optical properties of electrochromic materials can be controlled by the application of an electric field allowing recent development of new applications such as smart windows technology for indoor climate control and energy conservation. We report the fabrication of a single-walled nanotube (SWNT) thin film based electro-optical modulator controlled by ionic liquid polarization in which the active electrochromic layer is made of a film of semiconducting (SC-) SWNTs and the counter-electrode is composed of a film of metallic (MT-) SWNTs. Optimization of this electro-optical cell allows the operations with an optical modulation depth of 3.7 dB and a response time in the millisecond range, which is thousands of times faster than typical electrolyte-controlled devices. In addition, a dual electro-optical device was built utilizing electro-optically active SC-SWNT films for each electrode that allowed increasing modulation depth of 6.7 dB while preserving the speed of the response. PMID:27531707

  6. Electrochromic properties and performance of NiOx films and their corresponding all-thin-film flexible devices preparedby reactive DC magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Dong, Dongmei; Wang, Wenwen; Dong, Guobo; Zhang, Fan; He, Yingchun; Yu, Hang; Liu, Famin; Wang, Mei; Diao, Xungang

    2016-10-01

    Nickel oxide (NiOx) thin films were deposited by direct current magnetron sputtering technique onto flexible substrates with various oxygen (O2) partial pressures. The influence of O2 contents during deposition process on film structure, morphology, composition, optical and electrochromic (EC) characteristics of the films were investigated. The EC response for nonstoichiometric NiOx films shows a strong dependence on grain size variations and surface morphology. Finally, the multiple-layer stacks ITO/NiOx/Ta2O5:H/WO3/ITO were sequentially vacuum deposited over flexible polyethylene terephthalate plates based on the optimization of NiOx single layers. A large optical contrast up to 60% and a good durability are obtained for full device. To perform preliminary research on the mechanical properties within flexible devices, we introduced nontrivial changes to the interfacial properties by replacing the glass with flexible polymers. The effects were studied through static bending and the nano-scratch test.

  7. Thermally Cured Dual Functional Viologen-Based All-in-One Electrochromic Devices with Panchromatic Modulation.

    PubMed

    Kao, Sheng-Yuan; Lu, Hsin-Che; Kung, Chung-Wei; Chen, Hsin-Wei; Chang, Ting-Hsiang; Ho, Kuo-Chuan

    2016-02-17

    Vinyl benzyl viologen (VBV) was synthesized and utilized to obtain all-in-one thermally cured electrochromic devices (ECDs). The vinyl moiety of VBV monomer could react with methyl methacrylate (MMA) to yield bulky VBV/poly(methyl methacrylate) (PMMA) chains and even cross-linked network without the assistance of additional cross-linker. Both the bulky VBV/PMMA chains and the resulting polymer network can hinder the aggregation of the viologens and reduce the possibility of dimerization, rendering enhanced cycling stability. Large transmittance changes (ΔT) over 60% at both 570 and 615 nm were achieved when the VBV-based ECD was switched from 0 V to a low potential bias of 0.5 V. Ultimately, the dual functional of VBV molecules, serving simultaneously as a promising electrochromic material and a cross-linker, is fully utilized in the proposed electrochromic system, making its fabrication process much easier. Negligible decays in ΔT at both wavelengths were observed for the cured ECD after being subjected to 1000 repetitive cycles, while 17.1% and 22.0% decays were noticed at 570 and 615 nm, respectively, for the noncured ECD. In addition, the low voltage-driven feature of the VBV-based ECD enables it to be incorporated with phenyl viologen (PV), further expanding the absorption range of the ECD. Panchromatic characteristic of the proposed PV/VBV-based ECD was demonstrated while exhibiting ΔT over 60% at both wavelengths. Only 5.3% and 6.9% decays, corresponding at 570 and 615 nm, respectively, were observed in the PV/VBV-based ECD after 10 000 continuous cycles at bleaching/coloring voltages of 0/0.5 V with an interval of 10 s for both bleaching and coloring processes. PMID:26807824

  8. High-Performance Electrochromic Devices Based on Poly[Ni(salen)]-Type Polymer Films.

    PubMed

    Nunes, Marta; Araújo, Mariana; Fonseca, Joana; Moura, Cosme; Hillman, Robert; Freire, Cristina

    2016-06-01

    We report the application of two poly[Ni(salen)]-type electroactive polymer films as new electrochromic materials. The two films, poly[Ni(3-Mesalen)] (poly[1]) and poly[Ni(3-MesaltMe)] (poly[2]), were successfully electrodeposited onto ITO/PET flexible substrates, and their voltammetric characterization revealed that poly[1] showed similar redox profiles in LiClO4/CH3CN and LiClO4/propylene carbonate (PC), while poly[2] showed solvent-dependent electrochemical responses. Both films showed multielectrochromic behavior, exhibiting yellow, green, and russet colors according to their oxidation state, and promising electrochromic properties with high electrochemical stability in LiClO4/PC supporting electrolyte. In particular, poly[1] exhibited a very good electrochemical stability, changing color between yellow and green (λ = 750 nm) during 9000 redox cycles, with a charge loss of 34.3%, an optical contrast of ΔT = 26.2%, and an optical density of ΔOD = 0.49, with a coloration efficiency of η = 75.55 cm(2) C(-1). On the other hand, poly[2] showed good optical contrast for the color change from green to russet (ΔT = 58.5%), although with moderate electrochemical stability. Finally, poly[1] was used to fabricate a solid-state electrochromic device using lateral configuration with two figures of merit: a simple shape (typology 1) and a butterfly shape (typology 2); typology 1 showed the best performance with optical contrast ΔT = 88.7% (at λ = 750 nm), coloration efficiency η = 130.4 cm(2) C(-1), and charge loss of 37.0% upon 3000 redox cycles. PMID:27175794

  9. High-Performance Electrochromic Devices Based on Poly[Ni(salen)]-Type Polymer Films.

    PubMed

    Nunes, Marta; Araújo, Mariana; Fonseca, Joana; Moura, Cosme; Hillman, Robert; Freire, Cristina

    2016-06-01

    We report the application of two poly[Ni(salen)]-type electroactive polymer films as new electrochromic materials. The two films, poly[Ni(3-Mesalen)] (poly[1]) and poly[Ni(3-MesaltMe)] (poly[2]), were successfully electrodeposited onto ITO/PET flexible substrates, and their voltammetric characterization revealed that poly[1] showed similar redox profiles in LiClO4/CH3CN and LiClO4/propylene carbonate (PC), while poly[2] showed solvent-dependent electrochemical responses. Both films showed multielectrochromic behavior, exhibiting yellow, green, and russet colors according to their oxidation state, and promising electrochromic properties with high electrochemical stability in LiClO4/PC supporting electrolyte. In particular, poly[1] exhibited a very good electrochemical stability, changing color between yellow and green (λ = 750 nm) during 9000 redox cycles, with a charge loss of 34.3%, an optical contrast of ΔT = 26.2%, and an optical density of ΔOD = 0.49, with a coloration efficiency of η = 75.55 cm(2) C(-1). On the other hand, poly[2] showed good optical contrast for the color change from green to russet (ΔT = 58.5%), although with moderate electrochemical stability. Finally, poly[1] was used to fabricate a solid-state electrochromic device using lateral configuration with two figures of merit: a simple shape (typology 1) and a butterfly shape (typology 2); typology 1 showed the best performance with optical contrast ΔT = 88.7% (at λ = 750 nm), coloration efficiency η = 130.4 cm(2) C(-1), and charge loss of 37.0% upon 3000 redox cycles.

  10. Optical indices of lithiated electrochromic oxides

    SciTech Connect

    Rubin, M.; Rottkay, K. von; Wen, S.J.; Ozer, N.; Slack, J.

    1996-09-01

    Optical indices have been determined for thin films of several electrochromic oxide materials. One of the most important materials in electrochromic devices, WO{sub 3}, was thoroughly characterized for a range of electrochromic states by sequential injection of Li ions. Another promising material, Li{sub 0.5}Ni{sub 0.5}O, was also studied in detail. Less detailed results are presented for three other common lithium-intercalating electrochromic electrode materials: V{sub 2}O{sub 5}, LiCoO{sub 2}, and CeO{sub 2}-TiO{sub 2}. The films were grown by sputtering, pulsed laser deposition (PLD) and sol-gel techniques. Measurements were made using a combination of variable-angle spectroscopy ellipsometry and spectroradiometry. The optical constants were then extracted using physical and spectral models appropriate to each material. Optical indices of the underlying transparent conductors, determined in separate studies, were fixed in the models of this work. The optical models frequently agree well with independent physical measurements of film structure, particularly surface roughness by atomic force microscopy. Inhomogeneity due to surface roughness, gradient composition, and phase separation are common in both the transparent conductors and electrochromics, resulting sometimes in particularly complex models for these materials. Complete sets of data are presented over the entire solar spectrum for a range of colored states. This data is suitable for prediction of additional optical properties such as oblique transmittance and design of complete electrochromic devices.

  11. A new repeatable, optical writing and electrical erasing device based on photochromism and electrochromism of viologen

    NASA Astrophysics Data System (ADS)

    Gao, Li-ping; Wei, Jian; Wang, Yue-chuan; Ding, Guo-jing; Yang, Yu-lin

    2012-08-01

    New optical writing and electrical erasing devices have been successfully fabricated that exploit the photochromism and electrochromism of viologen. In a preliminary study, both the structures of viologen and device were investigated in detail by UV-vis spectra in order to confirm their effects on the optical writing and electrical erasing performances of corresponding devices. For sandwiched, single and complementary devices based on benzyl viologen (BV 2+), only optical writing can be performed, not electrical erasing operations, which indicated these devices cannot realize optical information rewriting. For single and complementary devices based on styrene-functional viologen (V BV 2+) and acrylic-functional viologen (ACV 2+), optical writing and electrical erasing operations can be reversibly performed and optical information rewriting realized. It is clear that single devices based on V BV2+ and ACV2+ possess better performance accompanied with contrast without significant degradation and bleaching times and without significant deterioration over 10 repeated writing/erasing cycles. Furthermore, we put forward possible mechanisms for sandwiched, single and complementary devices based on V BV2+ and ACV2+ for the optical writing and electrical erasing operations. This study provides a new strategy to design optical writing and electrical erasing devices to realize optical information rewriting.

  12. NIR-Selective electrochromic heteromaterial frameworks: a platform to understand mesoscale transport phenomena in solid-state electrochemical devices

    SciTech Connect

    Williams, TE; Chang, CM; Rosen, EL; Garcia, G; Runnerstrom, EL; Williams, BL; Koo, B; Buonsanti, R; Milliron, DJ; Helms, BA

    2014-01-01

    We report here the first solid-state, NIR-selective electrochromic devices. Critical to device performance is the arrangement of nanocrystal-derived electrodes into heteromaterial frameworks, where hierarchically porous ITO nanocrystal active layers are infiltrated by an ion-conducting polymer electrolyte with mesoscale periodicity. Enhanced coloration efficiency and transport are realized over unarchitectured electrodes in devices, paving the way towards new smart windows technologies.

  13. Electrochromism in sputter deposited W1-y MoyO3 thin films

    NASA Astrophysics Data System (ADS)

    Arvizu, M. A.; Granqvist, C. G.; Niklasson, G. A.

    2016-02-01

    Electrochromic (EC) properties of tungsten-molybdenum oxide (W1-y MoyO3) thin films were investigated. The films were deposited on indium tin oxide covered glass by reactive DC sputtering from tungsten and molybdenum targets. Elemental compositions of the W1-y MoyO3 films were determined by Rutherford back scattering. Voltammetric cycling was performed in an electrolyte of 1 M LiClO4 in propylene carbonate. An increase in molybdenum content in the EC films caused both a shift towards higher energies and a lowering of the maximum of the optical absorption band, as compared with WO3 EC films. Durability under electrochemical cycling was diminished for W1-y MoyO3 EC films.

  14. Far-infrared through visible optical characterization of polymer-based electrochromic devices on single-walled carbon nanotube electrodes

    NASA Astrophysics Data System (ADS)

    Nasrollahi, Zahra; Vasilyeva, Svetlana V.; Donoghue, Evan P.; Rinzler, Andrew G.; Tanner, D. B.

    2012-02-01

    Electrochromic polymers (ECPs) exhibit reversible optical modulation in a wide spectral range as a function of an externally applied voltage. In this work, ECPs have been used in absorptive/transmissive electrochromic devices as candidates for smart window applications. The electrochromic devices were fabricated on flexible polyethylene substrates and used ECPs sandwiched between thin films of single-walled carbon nanotubes serving as conductive and flexible electrodes. Unlike ITO, the nanotube films are highly transmissive in the visible and infrared region of the spectrum. The transmission and reflection of the individual device components as well as assembled devices were measured over a wide spectral range (FIR to UV). The devices were switched in situ in the spectrometers. The optical constants of the constituent layers were calculated using the Drude-Lorentz model. The devices demonstrated high transmission contrasts between their colored and bleached states in the VIS, NIR, and MIR spectra, enabling electrically tunable control over the transmission or reflection of both light and heat. This control could lead to reduced heating or cooling costs in real world applications and the flexible nature of the device components allows many applications.

  15. Electrochromic counter electrode

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland; Jorgensen, Gary J.

    2005-02-22

    The present invention discloses an amorphous material comprising nickel oxide doped with tantalum that is an anodically coloring electrochromic material. The material of the present invention is prepared in the form of an electrode (200) having a thin film (202) of an electrochromic material of the present invention residing on a transparent conductive film (203). The material of the present invention is also incorporated into an electrochromic device (100) as a thin film (102) in conjunction with a cathodically coloring prior art electrochromic material layer (104) such that the devices contain both anodically coloring (102) and cathodically coloring (104) layers. The materials of the electrochromic layers in these devices exhibit broadband optical complimentary behavior, ionic species complimentary behavior, and coloration efficiency complimentary behavior in their operation.

  16. Constructing three-dimensional quasi-vertical nanosheet architectures from self-assemble two-dimensional WO3·2H2O for efficient electrochromic devices

    NASA Astrophysics Data System (ADS)

    Li, Haizeng; Wang, Jinmin; Shi, Qiuwei; Zhang, Minwei; Hou, Chengyi; Shi, Guoying; Wang, Hongzhi; Zhang, Qinghong; Li, Yaogang; Chi, Qijin

    2016-09-01

    Three-dimensional (3D) quasi-vertical nanosheet (QVNS) architectures are of great importance in the application of electrochromic devices due to its 3D porous structures, large surface area and lamellar permeable space of nanosheets. In this study, we demonstrate successful preparing of WO3·2H2O nanosheets via a novel and facile solution route and repurposing the typical electrodeposition technique to obtain 3D QVNS electrodes. The electrode was successfully assembled into an electrochromic device which exhibits good electrochromic performance.

  17. Improving conducting polymer electrochromic speeds and depositing aligned polymeric nanofibers by electrospinning process

    NASA Astrophysics Data System (ADS)

    Asemota, Chris I.

    The effects of film thickness and porosity on electrochromic switching time of conducting polymers was pursued to determine the morphology influence on ions transport during oxidation step of the redox process, affording sub-second or seconds switching times. Electrospinning technique provided non-woven nanofiber mats, while spin coating and electropolymerization of monomer (N3T) provided films. Porosity decreased as depositing method changed from electrospinning to spin coating. In electrochemical oxidation, the electrons leave the polymer at the metal electrode-polymer film interface, and counter ions arrive at the polaron-bipolaron sites left in the polymer, through polymer-electrolyte interface. Counter ion diffusion in conducting polymers are film thickness limited at increasing thickness and inability of ions to reach holes sites on the oxidizing polymer accounts for long switching speeds, introducing extensive and micro pores and high surface areas should lead to decreasing electrochromic switching speed to single digit time in seconds (for display and vision applications), while increasing the maximum optical switching contrast due to increased fiber mat thicknesses. Photolithographic patterning of nanofiber mats of the conducting polymer precursor having photo cross-linking unit was also explored. The photo-crosslinkable polymer was prepared by including norborene methacrylate (NMA) units to the polymer backbone during precursor polymerization, yielding a terpolymer poly(N3T-NA-NMA). The influence of photo crosslinking on electrochemical switching in conducting polymer nanofibers, and effect of developing parameters (solvent and time) on pattern transfer to the nanofiber mat was investigated and showed no influence on the electrochemical redox of the polymer. Solvents suitable for dissolving the polymer were investigated as developers with results showing non-differentiable pattern transfer for all suitable solvents, and no net preference to solvent choice

  18. Electrochromic and colorimetric properties of nickel(II) oxide thin films prepared by aerosol-assisted chemical vapor deposition.

    PubMed

    Sialvi, Muhammad Z; Mortimer, Roger J; Wilcox, Geoffrey D; Teridi, Asri Mat; Varley, Thomas S; Wijayantha, K G Upul; Kirk, Caroline A

    2013-06-26

    Aerosol-assisted chemical vapor deposition (AACVD) was used for the first time in the preparation of thin-film electrochromic nickel(II) oxide (NiO). The as-deposited films were cubic NiO, with an octahedral-like grain structure, and an optical band gap that decreased from 3.61 to 3.48 eV on increase in film thickness (in the range 500-1000 nm). On oxidative voltammetric cycling in aqueous KOH (0.1 mol dm(-3)) electrolyte, the morphology gradually changed to an open porous NiO structure. The electrochromic properties of the films were investigated as a function of film thickness, following 50, 100, and 500 conditioning oxidative voltammetric cycles in aqueous KOH (0.1 mol dm(-3)). Light modulation of the films increased with the number of conditioning cycles. The maximum coloration efficiency (CE) for the NiO (transmissive light green, the "bleached" state) to NiOOH (deep brown, the colored state) electrochromic process was found to be 56.3 cm(2) C(-1) (at 450 nm) for films prepared by AACVD for 15 min followed by 100 "bleached"-to-colored conditioning oxidative voltammetric cycles. Electrochromic response times were <10 s and generally longer for the coloration than the bleaching process. The films showed good stability when tested for up to 10 000 color/bleach cycles. Using the CIE (Commission Internationale de l'Eclairage) system of colorimetry the color stimuli of the electrochromic NiO films and the changes that take place on reversibly oxidatively switching to the NiOOH form were calculated from in situ visible spectra recorded under electrochemical control. Reversible changes in the hue and saturation occur on oxidation of the NiO (transmissive light green) form to the NiOOH (deep brown) form, as shown by the track of the CIE 1931 xy chromaticity coordinates. As the NiO film is oxidized, a sharp decrease in luminance was observed. CIELAB L*a*b* coordinates were also used to quantify the electrochromic color states. A combination of a low L* and positive a

  19. Cyclic voltammetry on sputter-deposited films of electrochromic Ni oxide: Power-law decay of the charge density exchange

    SciTech Connect

    Wen, Rui-Tao Granqvist, Claes G.; Niklasson, Gunnar A.

    2014-10-20

    Ni-oxide-based thin films were produced by reactive direct-current magnetron sputtering and were characterized by X-ray diffraction and Rutherford backscattering spectroscopy. Intercalation of Li{sup +} ions was accomplished by cyclic voltammetry (CV) in an electrolyte of LiClO{sub 4} in propylene carbonate, and electrochromism was documented by spectrophotometry. The charge density exchange, and hence the optical modulation span, decayed gradually upon repeated cycling. This phenomenon was accurately described by an empirical power law, which was valid for at least 10{sup 4} cycles when the applied voltage was limited to 4.1 V vs Li/Li{sup +}. Our results allow lifetime assessments for one of the essential components in an electrochromic device such as a “smart window” for energy-efficient buildings.

  20. Cyclic voltammetry on sputter-deposited films of electrochromic Ni oxide: Power-law decay of the charge density exchange

    NASA Astrophysics Data System (ADS)

    Wen, Rui-Tao; Granqvist, Claes G.; Niklasson, Gunnar A.

    2014-10-01

    Ni-oxide-based thin films were produced by reactive direct-current magnetron sputtering and were characterized by X-ray diffraction and Rutherford backscattering spectroscopy. Intercalation of Li+ ions was accomplished by cyclic voltammetry (CV) in an electrolyte of LiClO4 in propylene carbonate, and electrochromism was documented by spectrophotometry. The charge density exchange, and hence the optical modulation span, decayed gradually upon repeated cycling. This phenomenon was accurately described by an empirical power law, which was valid for at least 104 cycles when the applied voltage was limited to 4.1 V vs Li/Li+. Our results allow lifetime assessments for one of the essential components in an electrochromic device such as a "smart window" for energy-efficient buildings.

  1. TiO2 nanowires for potential facile integration of solar cells and electrochromic devices.

    PubMed

    Qiang, Pengfei; Chen, Zhongwei; Yang, Peihua; Cai, Xiang; Tan, Shaozao; Liu, Pengyi; Mai, Wenjie

    2013-11-01

    Self-powered systems usually consist of energy-acquisition components, energy-storage components and functional components. The development of nanoscience and nanotechnology has greatly improved the performance of all the components of self-powered systems. However, huge differences in the materials and configurations in the components cause large difficulties for integration and miniaturization of self-powered systems. Design and fabrication of different components in a self-powered system with the same or similar materials/configurations should be able to make the above goal easier. In this work, a proof-of-concept experiment involving an integrated self-powered color-changing system consisting of TiO2 nanowire based sandwich dye-sensitized solar cells (DSSCs) and electrochromic devices (ECDs) is designed and demonstrated. When sunlight illuminates the entire system, the DSSCs generate electrical power and turn the ECD to a darker color, dimming the light; by switching the connection polarity of the DSSCs, the lighter color can be regained, implying the potential application of this self-powered color-changing system for next generation sun glasses and smart windows. PMID:24107414

  2. TiO2 nanowires for potential facile integration of solar cells and electrochromic devices.

    PubMed

    Qiang, Pengfei; Chen, Zhongwei; Yang, Peihua; Cai, Xiang; Tan, Shaozao; Liu, Pengyi; Mai, Wenjie

    2013-11-01

    Self-powered systems usually consist of energy-acquisition components, energy-storage components and functional components. The development of nanoscience and nanotechnology has greatly improved the performance of all the components of self-powered systems. However, huge differences in the materials and configurations in the components cause large difficulties for integration and miniaturization of self-powered systems. Design and fabrication of different components in a self-powered system with the same or similar materials/configurations should be able to make the above goal easier. In this work, a proof-of-concept experiment involving an integrated self-powered color-changing system consisting of TiO2 nanowire based sandwich dye-sensitized solar cells (DSSCs) and electrochromic devices (ECDs) is designed and demonstrated. When sunlight illuminates the entire system, the DSSCs generate electrical power and turn the ECD to a darker color, dimming the light; by switching the connection polarity of the DSSCs, the lighter color can be regained, implying the potential application of this self-powered color-changing system for next generation sun glasses and smart windows.

  3. TiO2 nanowires for potential facile integration of solar cells and electrochromic devices

    NASA Astrophysics Data System (ADS)

    Qiang, Pengfei; Chen, Zhongwei; Yang, Peihua; Cai, Xiang; Tan, Shaozao; Liu, Pengyi; Mai, Wenjie

    2013-11-01

    Self-powered systems usually consist of energy-acquisition components, energy-storage components and functional components. The development of nanoscience and nanotechnology has greatly improved the performance of all the components of self-powered systems. However, huge differences in the materials and configurations in the components cause large difficulties for integration and miniaturization of self-powered systems. Design and fabrication of different components in a self-powered system with the same or similar materials/configurations should be able to make the above goal easier. In this work, a proof-of-concept experiment involving an integrated self-powered color-changing system consisting of TiO2 nanowire based sandwich dye-sensitized solar cells (DSSCs) and electrochromic devices (ECDs) is designed and demonstrated. When sunlight illuminates the entire system, the DSSCs generate electrical power and turn the ECD to a darker color, dimming the light; by switching the connection polarity of the DSSCs, the lighter color can be regained, implying the potential application of this self-powered color-changing system for next generation sun glasses and smart windows.

  4. Vacuum arc deposition devices

    NASA Astrophysics Data System (ADS)

    Boxman, R. L.; Zhitomirsky, V. N.

    2006-02-01

    The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

  5. Vacuum arc deposition devices

    SciTech Connect

    Boxman, R.L.; Zhitomirsky, V.N.

    2006-02-15

    The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

  6. A comparative study of the electrochemical behavior of complementary polymer electrochromic devices based on different counter-electrodes

    NASA Astrophysics Data System (ADS)

    Du, Qing; Mi, Sai; Zheng, Jianming; Xu, Chunye

    2013-12-01

    8,11-di-(4-thiophen-2-yl)acenaphtho[1,2-b]quinoxaline (DTAQ) was successfully synthesized via a Stille coupling reaction and the corresponding polymer (PDTAQ) was prepared electrochemically. The spectroelectrochemical and electrochromic properties of the polymer film reveal that PDTAQ film shows distinct color states (purple in the neutral state and blue in the oxidized state), and optical contrast (ΔT%) of 45.16% at 772 nm and 49.39% at 1100 nm with switching times of 2.5 and 0.5 s. Complementary electrochromic devices, which are based on the PDTAQ film as the working electrode, Prussian blue (PB) and V2O5 as counter-electrodes, respectively, and LiClO4/PC solution as the electrolyte, were assembled and characterized. The results illustrate that the properties of the PDTAQ/PB and PDTAQ/V2O5 devices (including the absorption, color changes, ΔT% and response times) can be modified by the counter-electrodes. Furthermore, the PDTAQ/V2O5 device exhibits a significantly higher contrast ratio in the visible region (34.92% at 771 nm) and much faster response time (0.4 s) than the PDTAQ/PB device (21.32% at 552 nm).

  7. Development of High Rate Coating Technology for Low Cost Electrochromic Dynamic Windows

    SciTech Connect

    Kwak, B.; Joshi, Ajey

    2013-03-31

    Objectives of the Project: The objective of this project was to develop and demonstrate the feasibility of depositing critical electrochromic layers at high rate using new novel vacuum coating sources, to develop a full electrochromic process flow by combining conventional processes with new deposition sources, to characterize, test, evaluate, and optimize the resulting coatings and devices, and, to demonstrate an electrochromic device using the new process flow and sources. As addendum objectives, this project was to develop and demonstrate direct patterning methods with novel integration schemes. The long term objective, beyond this program, is to integrate these innovations to enable production of low-cost, high-performance electrochromic windows produced on highly reliable and high yielding manufacturing equipment and systems.

  8. Photovoltaic Powering And Control System For Electrochromic Windows

    DOEpatents

    Schulz, Stephen C.; Michalski, Lech A.; Volltrauer, Hermann N.; Van Dine, John E.

    2000-04-25

    A sealed insulated glass unit is provided with an electrochromic device for modulating light passing through the unit. The electrochromic device is controlled from outside the unit by a remote control electrically unconnected to the device. Circuitry within the unit may be magnetically controlled from outside. The electrochromic device is powered by a photovoltaic cells. The photovoltaic cells may be positioned so that at least a part of the light incident on the cell passes through the electrochromic device, providing a form of feedback control. A variable resistance placed in parallel with the electrochromic element is used to control the response of the electrochromic element to changes in output of the photovoltaic cell.

  9. In-situ characterization of electrochromism based on ITO/PEDOT:PSS towards preparation of high performance device

    NASA Astrophysics Data System (ADS)

    Xue-Jin, Wang; Zheng-Fei, Guo; Jing-Yu, Qu; Kun, Pan; Zheng, Qi; Li, Hong

    2016-02-01

    Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is usually sandwiched between indium tin oxide (ITO) and a functional polymer in order to improve the performance of the device. However, because of the strong acidic nature of PEDOT:PSS, the instability of ITO/PEDOT:PSS interface is also observed. The mechanism of degradation of the device remains is unclear and needs to be further studied. In this article, we investigate the in-situ electrochromism of PEDOT:PSS to disclose the cause of the degradation. X-ray photoelectron spectroscopy (XPS) was used to characterize the PEDOT:PSS films, as well as the PEDOT:PSS plus polyethylene glycol (PEG) films with and without indium ions. The electrochromic devices (ECD) based on PEDOT:PSS and PEG with and without indium ions are carried out by in-situ micro-Raman and laser reflective measurement (LRM). For comparison, ECD based on PEDOT:PSS and PEG films with LiCl, KCl, NaCl or InCl3 are also investigated by LRM. The results show that PEDOT:PSS is further reduced when negatively biased, and oxidized when positively biased. This could identify that PEDOT:PSS with indium ions from PEDOT:PSS etching ITO will lose dopants when negatively biased. The LRM shows that the device with indium ions has a stronger effect on the reduction property of PEDOT:PSS-PEG film than the device without indium ions. The contrast of the former device is 44%, that of the latter device is about 3%. The LRM also shows that the contrasts of the device based on PEDOT:PSS+PEG with LiCl, KCl, NaCl, InCl3 are 30%, 27%, 15%, and 18%, respectively. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA034201) and the Chinese Universities Scientific Fund (Grant No. 2015LX002).

  10. Li(+)- and Eu(³+)-doped poly(ε-caprolactone)/siloxane biohybrid electrolytes for electrochromic devices.

    PubMed

    Fernandes, M; Nobre, S S; Rodrigues, L C; Gonçalves, A; Rego, R; Oliveira, M C; Ferreira, R A S; Fortunato, E; Silva, M M; Carlos, L D; Bermudez, V de Zea

    2011-08-01

    The sol-gel process has been successfully combined with the "mixed cation" effect to produce novel luminescent and ion conducting biohybrids composed of a diurethane cross-linked poly(ε-caprolactone) (PCL530)/siloxane hybrid network (PCL stands for the poly(ε-caprolactone) biopolymer and 530 is the average molecular weight in gmol(-1)) doped with a wide range of concentrations of lithium and europium triflates (LiCF(3)SO(3) and Eu(CF(3)SO(3))(3), respectively) (molar ratio of ca. 50:50). The hybrid samples are all semicrystalline: whereas at n = 52.6 and 27.0 (n, composition, corresponds to the number of (C(═O)(CH(2))(5)O) repeat units of PCL(530) per mixture of Li(+) and Eu(3+) ions) a minor proportion of crystalline PCL(530) chains is present, at n = 6.1, a new crystalline phase emerges. The latter electrolyte is thermally stable up to 220 °C and exhibits the highest conductivity over the entire range of temperatures studied (3.7 × 10(-7) and 1.71 × 10(-4) S cm(-1) at 20 and 102 °C, respectively). According to infrared spectroscopic data, major modifications occur in terms of hydrogen bonding interactions at this composition. The electrochemical stability domain of the biohybrid sample with n = 27 spans more than 7 V versus Li/Li(+). This sample is a room temperature white light emitter. Its emission color can be easily tuned across the Commission Internationale d'Éclairage (CIE) chromaticity diagram upon simply changing the excitation wavelength. Preliminary tests performed with a prototype electrochromic device (ECD) comprising the sample with n = 6.1 as electrolyte and WO(3) as cathodically coloring layer are extremely encouraging. The device exhibits switching time around 50 s, an optical density change of 0.15, good open circuit memory under atmospheric conditions (ca. 1 month) and high coloration efficiency (577 cm(2) C(-1) in the second cycle). PMID:21774498

  11. A dual-polymer electrochromic device with high coloration efficiency and fast response time: poly(3,4-(1,4-butylene-(2-ene)dioxy)thiophene)-polyaniline ECD.

    PubMed

    Kang, Joo-Hee; Xu, Zhaochao; Paek, Seung-Min; Wang, Fang; Hwang, Seong-Ju; Yoon, Juyoung; Choy, Jin-Ho

    2011-08-01

    A new dual-polymer electrochromic device (ECD) composed of poly(3,4-(1,4-butylene-(2-ene)dioxy)thiophene) (PBueDOT) and polyaniline (PANI) with a hydrophobic molten salt electrolyte has been developed. To build this system, an alkylenedioxy ring in the BueDOT backbone was expanded to include a strongly electron-donating alkylenedioxy bridge, and the thickness and surface morphology of the corresponding PBueDOT film were controlled systematically. Not only the dual-electrochromic-polymer-electrode system, but also the expanded alkylenedioxy ring in the BueDOT backbone, synergistically improved the electrochromic performance. From the coloration efficiency (CE) value calculations, we found that the CE was enhanced up to 930 cm(2) C(-1). Furthermore, these ECDs showed an extremely fast response time of less than 80 ms.

  12. High performance hybrid rGO/Ag quasi-periodic mesh transparent electrodes for flexible electrochromic devices

    NASA Astrophysics Data System (ADS)

    Voronin, A. S.; Ivanchenko, F. S.; Simunin, M. M.; Shiverskiy, A. V.; Aleksandrovsky, A. S.; Nemtsev, I. V.; Fadeev, Y. V.; Karpova, D. V.; Khartov, S. V.

    2016-02-01

    A possibility of creating a stable hybrid coating based on the hybrid of a reduced graphene oxide (rGO)/Ag quasi-periodic mesh (q-mesh) coating has been demonstrated. The main advantages of the suggested method are the low cost of the processes and the technology scalability. The Ag q-mesh coating is formed by means of the magnetron sputtering of silver on the original template obtained as a result of quasi-periodic cracking of a silica film. The protective rGO film is formed by low temperature reduction of a graphene oxide (GO) film, applied by the spray-deposition in the solution of NaBH4. The coatings have low sheet resistance (12.3 Ω/sq) and high optical transparency (82.2%). The hybrid coatings are characterized by high chemical stability, as well as they show high stability to deformation impacts. High performance of the hybrid coatings as electrodes in the sandwich-system «electrode-electrochromic composition-electrode» has been demonstrated. The hybrid electrodes allow the electrochromic sandwich to function without any visible degradation for a long time, while an unprotected mesh electrode does not allow performing even a single switching cycle.

  13. High optical and switching performance electrochromic devices based on a zinc oxide nanowire with poly(methyl methacrylate) gel electrolytes

    SciTech Connect

    Chun, Young Tea; Chu, Daping; Neeves, Matthew; Placido, Frank; Smithwick, Quinn

    2014-11-10

    High performance electrochromic devices have been fabricated and demonstrated utilizing a solid polymer electrolyte and zinc oxide (ZnO) nanowire (NW) array counter electrode. The poly(methyl methacrylate) based polymer electrolyte was spin coated upon hydrothermally grown ZnO NW array counter electrodes, while electron beam evaporated NiO{sub x} thin films formed the working electrodes. Excellent optical contrast and switching speeds were observed in the fabricated devices with active areas of 2 cm{sup 2}, exhibiting an optical contrast of 73.11% at the wavelength of 470 nm, combined with a fast switching time of 0.2 s and 0.4 s for bleaching and coloration, respectively.

  14. Sputter deposited W1-x-yNixTiyO3 thin films: Electrochromic properties and durability

    NASA Astrophysics Data System (ADS)

    Morales-Luna, M.; Arvizu, M. A.; Granqvist, C. G.; Niklasson, G. A.

    2016-02-01

    Previous research demonstrated that a small amount of nickel enhances the coloration efficiency of tungsten-nickel oxide electrochromic (EC) thin films with respect to that of pure tungsten oxide (WO3) films. Furthermore the incorporation of titanium gives an improvement in the durability of tungsten-titanium oxide EC thin films. In this work we investigated the EC performance of tungsten-nickel-titanium oxide (W1-x-yNixTiyO3) EC thin films with emphasis on durability. The films were deposited on indium tin oxide covered glass by reactive dc sputtering from tungsten, tungsten-titanium alloy and nickel targets. Cyclic voltammetry was performed using 1 M LiClO4 in propylene carbonate as electrolyte. The voltage window was chosen to induce fast degradation of the samples within 80 cycles. Elemental compositions were obtained by Rutherford Backscattering Spectroscopy.

  15. Electrochromic Characterization of Electrodeposited WO3 Thin Films

    NASA Astrophysics Data System (ADS)

    Vijayalakshmi, R.; Jayachandran, M.; Sanjeeviraja, C.

    2002-12-01

    The electrochromic properties of certain transition metal oxides have been studied for several years resulting in commercial films are deposited as thin layers (0.1 to 0.4 microns) onto a transparent conductive automotive mirror and sun-glass products. The largest potential application of electrochromics is in window to regulate heat and light flow. Fabrication cost is one of the greatest barriers for large area development of the smart windows. Tungsten trioxide (WO3) can be colored deeply in with an optical irradiation of appropriate energy (photochromism) or with an applied electric field (electrochromism). These processes have received considerable attention because of their potential application in electrochromic windows, display devices, sensors, and so on. For these purposes, tungsten trioxide films prepared by various physical methods such as molecular beam epitaxy, CVD, etc have been reported. These methods are generally expensive and it is difficult to form large area films. However electrodeposition method is probably most economical method for making the films in addition to its relative ease in forming in large area films. In this paper, tungsten trioxide (WO3) films are prepared through the electrodeposition route and these films are used to study the electrochromic behavior in the various electrolytes by changing the concentrations. When coloration, the film attains deep blue color and in reduced state it becomes colorless. After the ion intercalation, the optical properties are also studied in the UV-Vis-NIR region.

  16. Solid state electrochromic light modulator

    SciTech Connect

    Cogan, S.F.; Rauh, R.D.

    1990-07-03

    An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counter electrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films. 4 figs.

  17. Solid state electrochromic light modulator

    DOEpatents

    Cogan, Stuart F.; Rauh, R. David

    1993-01-01

    An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

  18. Solid state electrochromic light modulator

    DOEpatents

    Cogan, Stuart F.; Rauh, R. David

    1990-01-01

    An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

  19. Solid state electrochromic light modulator

    DOEpatents

    Cogan, Stuart F.; Rauh, R. David

    1993-12-07

    An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

  20. Flexible electrochromic films based on CVD-graphene electrodes.

    PubMed

    Soo Choi, Dong; Ho Han, Seung; Kim, Hyeongkeun; Hee Kang, So; Kim, Yena; Yang, Cheol-Min; Kim, Tae Young; Ho Yoon, Dae; Seok Yang, Woo

    2014-10-01

    Graphene synthesized via chemical vapor deposition is a notable candidate for flexible large-area transparent electrodes due to its great physical properties and its 2D activated surface area. Electrochromic devices in optical displays, smart windows, etc are suitable applications for graphene when used as a transparent conductive electrode. In this study, various-layer graphene was synthesized via chemical vapor deposition, and inorganic WO(x) was deposited on the layers, which have advantageous columnar structures and W(6+) and W(4+) oxidation states. The characteristics of graphene and WO(x) were verified using optical transmittance, Raman spectroscopy, x-ray photoelectron spectroscopy and scanning electron microscopy. The optimum transparent conductive electrode condition for controlling graphene layers was investigated based on the optical density and cyclic voltammetry. Electrochromic devices were fabricated using a three-layer graphene electrode, which had the best optical density. The graphene in the flexible electrochromic device demonstrated a potential for replacing ITO in flexible electronics. PMID:25201016

  1. An Electrochromic Bipolar Membrane Diode.

    PubMed

    Malti, Abdellah; Gabrielsson, Erik O; Crispin, Xavier; Berggren, Magnus

    2015-07-01

    Conducting polymers with bipolar membranes (a complementary stack of selective membranes) may be used to rectify current. Integrating a bipolar membrane into a polymer electrochromic display obviates the need for an addressing backplane while increasing the device's bistability. Such devices can be made from solution-processable materials.

  2. Oxide coatings on flexible substrates for electrochromic applications

    NASA Astrophysics Data System (ADS)

    Aleksandrova, M.

    2014-11-01

    One of the most studied classes of materials in the modern microelectronic devices are the metal oxides. There are different metal oxide films, such as electrodes, charge injecting and electrochromic coatings for displays or "smart" windows applications. This paper aims to describe the recent achievements for oxide coating deposition for flexible electrochromic displays. Although many deposition methods for production of such films have been developed, some of the achievements in the field of RF sputtering of transparent electrodes from indium-tin oxide on low-cost polyethyleneterephthalate substrate are presented. Attention is paid on some critical issues, such as films electro-optical parameters (sheet resistance, transparency in the visible range), adhesion, degradation due to stress and patterning ability.

  3. Zirconium dioxide nanofilled poly(vinylidene fluoride-hexafluoropropylene) complexed with lithium trifluoromethanesulfonate as composite polymer electrolyte for electrochromic devices

    SciTech Connect

    Puguan, John Marc C.; Chinnappan, Amutha; Kostjuk, Sergei V.; Kim, Hern

    2015-09-15

    Highlights: • Successful synthesis of electrolyte by blending PVdF-HFP, ZrO{sub 2} and LiCF{sub 3}SO{sub 3}. • ZrO{sub 2} increased electrolyte conductivity by two orders of magnitude. • ZrO{sub 2} doubled bulk mechanical strength of electrolyte in terms of Young’s modulus. • Electrolytes gave a optimum optical transmittance of 52.6%. - Abstract: Poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) polymer electrolyte containing zirconium dioxide nanocrystals (ZrO{sub 2}-NC) and lithium trifluoromethanesulfonate (LiCF{sub 3}SO{sub 3}) has been synthesized using the conventional solution casting method. The addition of ZrO2-NC into the polymeric substrate gave remarkable properties in terms of the electrolyte’s ionic conductivity as well as its bulk mechanical strength. The enhanced amorphicity of the polymeric substrate due to ZrO{sub 2} and the nanofiller’s high dielectric constant make an excellent combination to increase the ionic conductivity (above 10{sup −4} S cm{sup −1}). Increasing the nanofiller content raises the ionic conductivity of the electrolyte by two orders of magnitude of which the optimum is 2.65 × 10{sup −4} S cm{sup −1} at 13.04 wt% ZrO{sub 2}-NC loading. Also, the Young’s modulus, an indicator of electrolyte’s mechanical stability, dramatically increased to 207 MPa upon loading 13.04 wt% ZrO{sub 2}-NC. Using UV–vis spectroscopy, the electrolytes with 13.04% ZrO{sub 2}-NC scanned from 200–800 nm wavelengths exhibited a maximum optical transmittance of 52.6% at 10 μm film thickness. The enhanced conductivity, high mechanical strength and reasonable optical transmittance shown by our composite polymer electrolyte make an excellent electrolyte for future energy saving smart windows such as electrochromic devices.

  4. Source replenishment device for vacuum deposition

    DOEpatents

    Hill, R.A.

    1986-05-15

    A material source replenishment device for use with a vacuum deposition apparatus is described. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  5. Source replenishment device for vacuum deposition

    DOEpatents

    Hill, Ronald A.

    1988-01-01

    A material source replenishment device for use with a vacuum deposition apparatus. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  6. A monolithic thin film electrochromic window

    SciTech Connect

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K.; Wei, G.; Yu, P.C.

    1991-12-31

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  7. A monolithic thin film electrochromic window

    SciTech Connect

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. . Electro-Optics Technology Center); Wei, G. ); Yu, P.C. )

    1991-01-01

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  8. Preparation and properties of all-solid-state inorganic thin film glass/ITO/WO3/LiNbO3/NiOx/ITO electrochromic device

    NASA Astrophysics Data System (ADS)

    Wu, Zhonghou; Diao, Xungang; Dong, Guobo

    2016-01-01

    The all-thin-film inorganic electrochromic device (ECD) with LiNbO3 as the ion conductor layer was prepared. The ECD was fabricated monolithically in a same vacuum chamber layer by layer using DC reactive sputtering for WO3, NiOx and ITO, and radio frequency (RF) sputtering for LiNbO3. The properties and performance of WO3 thin film and the ECD were studied through X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible spectrometry. WO3 thin film has more than 60% optical modulation with porous amorphous structure. The visible transmittance modulation of the ECD is more than 65%, and the response time of coloring and bleaching are 45 s and 25 s, respectively.

  9. Electrochromic Windows: Advanced Processing Technology

    SciTech Connect

    SAGE Electrochromics, Inc

    2006-12-13

    This project addresses the development of advanced fabrication capabilities for energy saving electrochromic (EC) windows. SAGE EC windows consist of an inorganic stack of thin films deposited onto a glass substrate. The window tint can be reversibly changed by the application of a low power dc voltage. This property can be used to modulate the amount of light and heat entering buildings (or vehicles) through the glazings. By judicious management of this so-called solar heat gain, it is possible to derive significant energy savings due to reductions in heating lighting, and air conditioning (HVAC). Several areas of SAGE’s production were targeted during this project to allow significant improvements to processing throughput, yield and overall quality of the processing, in an effort to reduce the cost and thereby improve the market penetration. First, the overall thin film process was optimized to allow a more robust set of operating points to be used, thereby maximizing the yield due to the thin film deposition themselves. Other significant efforts aimed at improving yield were relating to implementing new procedures and processes for the manufacturing process, to improve the quality of the substrate preparation, and the quality of the IGU fabrication. Furthermore, methods for reworking defective devices were developed, to enable devices which would otherwise be scrapped to be made into useful product. This involved the in-house development of some customized equipment. Finally, the improvements made during this project were validated to ensure that they did not impact the exceptional durability of the SageGlass® products. Given conservative estimates for cost and market penetration, energy savings due to EC windows in residences in the US are calculated to be of the order 0.026 quad (0.026×1015BTU/yr) by the year 2017.

  10. All-solid-state electrochromic device integrated with near-IR blocking layer for image sensor and energy-saving glass application

    NASA Astrophysics Data System (ADS)

    Wang, Min-Chuan; Hsieh, Ming-Hao; Chen, Yung-Chih; Wang, Jen-Yuan

    2016-09-01

    The all-solid-state electrochromic device (ECD) integrated with near-IR (NIR) blocking layer fabricated by reactive DC magnetron sputtering technique has been developed for image sensor and energy-saving glass applications. The all-solid-state ECD with the single-substrate structure of glass/NIR-blocking transparent conductive oxide (TCO)/NiO/Ta2O5/WO3/ITO could potentially modulate the optical transmittance between 81.9% and 17.5% at 550 nm in the visible region and between 38.0% and 9.5% at the NIR wavelength larger than 1100 nm. The better energy-saving and light blocking performance, including the larger optical density difference (ΔOD) and lower solar heat-gain coefficient (SHGC) could be achieved in the NIR-blocking ECD structure, even with the general criteria SHGC(bleach)/SHGC(colored) < 3. With the application of ECDs, it is possible to directly apply the device onto an image sensor and energy-saving glass with the NIR rejection function even in the bleached state. Furthermore, the NIR-blocking TCO with the low sheet resistance and high transparency characteristics also provides the lower power consumption in the switching cycle at voltages as low as 5 V, and makes ECDs the ideal components for applications of large area and battery powered devices.

  11. Deposition Diagnostics for Next-step Devices

    SciTech Connect

    C.H. Skinner; A.L. Roquemore; the NSTX team; A. Bader; W.R. Wampler

    2004-06-15

    The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX.

  12. Sulfonic Acid- and Lithium Sulfonate-Grafted Poly(Vinylidene Fluoride) Electrospun Mats As Ionic Liquid Host for Electrochromic Device and Lithium-Ion Battery.

    PubMed

    Zhou, Rui; Liu, Wanshuang; Leong, Yew Wei; Xu, Jianwei; Lu, Xuehong

    2015-08-01

    Electrospun polymer nanofibrous mats loaded with ionic liquids (ILs) are promising nonvolatile electrolytes with high ionic conductivity. The large cations of ILs are, however, difficult to diffuse into solid electrodes, making them unappealing for application in some electrochemical devices. To address this issue, a new strategy is used to introduce proton conduction into an IL-based electrolyte. Poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) copolymer is functionalized with sulfonic acid through covalent attachment of taurine. The sulfonic acid-grafted P(VDF-HFP) electrospun mats consist of interconnected nanofibers, leading to remarkable improvement in dimensional stability of the mats. IL-based polymer electrolytes are prepared by immersing the modified mats in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(+)BF4(-)). It is found that the SO3(-) groups can have Lewis acid-base interactions with the cations (BMIM(+)) of IL to promote the dissociation of ILs, and provide additional proton conduction, resulting in significantly improved ionic conductivity. Using this novel electrolyte, polyaniline-based electrochromic devices show higher transmittance contrast and faster switching behavior. Furthermore, the sulfonic acid-grafted P(VDF-HFP) electrospun mats can also be lithiated, giving additional lithium ion conduction for the IL-based electrolyte, with which Li/LiCoO2 batteries display enhanced C-rate performance.

  13. Electrochromic Windows: Process and Fabrication Improvements for Lower Total Costs

    SciTech Connect

    Mark Burdis; Neil Sbar

    2007-03-31

    The overall goal with respect to the U.S. Department of Energy (DOE) is to achieve significant national energy savings through maximized penetration of EC windows into existing markets so that the largest cumulative energy reduction can be realized. The speed with which EC windows can be introduced and replace current IGU's (and current glazings) is clearly a strong function of cost. Therefore, the aim of this project was to investigate possible improvements to the SageGlass{reg_sign} EC glazing products to facilitate both process and fabrication improvements resulting in lower overall costs. The project was split into four major areas dealing with improvements to the electrochromic layer, the capping layer, defect elimination and general product improvements. Significant advancements have been made in each of the four areas. These can be summarized as follows: (1) Plasma assisted deposition for the electrochromic layer was pursued, and several improvements made to the technology for producing a plasma beam were made. Functional EC devices were produced using the new technology, but there are still questions to be answered regarding the intrinsic properties of the electrochromic films produced by this method. (2) The capping layer work was successfully implemented into the existing SageGlass{reg_sign} product, thereby providing a higher level of transparency and somewhat lower reflectivity than the 'standard' product. (3) Defect elimination is an ongoing effort, but this project spurred some major defect reduction programs, which led to significant improvements in yield, with all the implicit benefits afforded. In particular, major advances were made in the development of a new bus bar application process aimed at reducing the numbers of 'shorts' developed in the finished product, as well as making dramatic improvements in the methods used for tempering the glass, which had previously been seen to produce a defect which appeared as a pinhole. (4) Improvements have

  14. Integrated electrochromic aperture diaphragm

    NASA Astrophysics Data System (ADS)

    Deutschmann, T.; Oesterschulze, E.

    2014-05-01

    In the last years, the triumphal march of handheld electronics with integrated cameras has opened amazing fields for small high performing optical systems. For this purpose miniaturized iris apertures are of practical importance because they are essential to control both the dynamic range of the imaging system and the depth of focus. Therefore, we invented a micro optical iris based on an electrochromic (EC) material. This material changes its absorption in response to an applied voltage. A coaxial arrangement of annular rings of the EC material is used to establish an iris aperture without need of any mechanical moving parts. The advantages of this device do not only arise from the space-saving design with a thickness of the device layer of 50μm. But it also benefits from low power consumption. In fact, its transmission state is stable in an open circuit, phrased memory effect. Only changes of the absorption require a voltage of up to 2 V. In contrast to mechanical iris apertures the absorption may be controlled on an analog scale offering the opportunity for apodization. These properties make our device the ideal candidate for battery powered and space-saving systems. We present optical measurements concerning control of the transmitted intensity and depth of focus, and studies dealing with switching times, light scattering, and stability. While the EC polymer used in this study still has limitations concerning color and contrast, the presented device features all functions of an iris aperture. In contrast to conventional devices it offers some special features. Owing to the variable chemistry of the EC material, its spectral response may be adjusted to certain applications like color filtering in different spectral regimes (UV, optical range, infrared). Furthermore, all segments may be switched individually to establish functions like spatial Fourier filtering or lateral tunable intensity filters.

  15. High-contrast and fast electrochromic switching enabled by plasmonics.

    PubMed

    Xu, Ting; Walter, Erich C; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri J; Talin, A Alec

    2016-01-01

    With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the complexity of having to combine several distinct polymers to achieve a full-colour gamut, have limited electrochromic materials to niche applications. Here we achieve fast, high-contrast electrochromic switching by significantly enhancing the interaction of light--propagating as deep-subwavelength-confined surface plasmon polaritons through arrays of metallic nanoslits, with an electrochromic polymer--present as an ultra-thin coating on the slit sidewalls. The switchable configuration retains the short temporal charge-diffusion characteristics of thin electrochromic films, while maintaining the high optical contrast associated with thicker electrochromic coatings. We further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-colour response with high contrast and fast switching speeds, while relying on just one electrochromic polymer. PMID:26814453

  16. High-contrast and fast electrochromic switching enabled by plasmonics

    PubMed Central

    Xu, Ting; Walter, Erich C.; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri J.; Talin, A. Alec

    2016-01-01

    With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the complexity of having to combine several distinct polymers to achieve a full-colour gamut, have limited electrochromic materials to niche applications. Here we achieve fast, high-contrast electrochromic switching by significantly enhancing the interaction of light—propagating as deep-subwavelength-confined surface plasmon polaritons through arrays of metallic nanoslits, with an electrochromic polymer—present as an ultra-thin coating on the slit sidewalls. The switchable configuration retains the short temporal charge-diffusion characteristics of thin electrochromic films, while maintaining the high optical contrast associated with thicker electrochromic coatings. We further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-colour response with high contrast and fast switching speeds, while relying on just one electrochromic polymer. PMID:26814453

  17. High-contrast and fast electrochromic switching enabled by plasmonics.

    PubMed

    Xu, Ting; Walter, Erich C; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri J; Talin, A Alec

    2016-01-27

    With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the complexity of having to combine several distinct polymers to achieve a full-colour gamut, have limited electrochromic materials to niche applications. Here we achieve fast, high-contrast electrochromic switching by significantly enhancing the interaction of light--propagating as deep-subwavelength-confined surface plasmon polaritons through arrays of metallic nanoslits, with an electrochromic polymer--present as an ultra-thin coating on the slit sidewalls. The switchable configuration retains the short temporal charge-diffusion characteristics of thin electrochromic films, while maintaining the high optical contrast associated with thicker electrochromic coatings. We further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-colour response with high contrast and fast switching speeds, while relying on just one electrochromic polymer.

  18. High-contrast and fast electrochromic switching enabled by plasmonics

    DOE PAGESBeta

    Xu, Ting; Walter, Erich C.; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri J.; Talin, A. Alec

    2016-01-27

    With vibrant colours and simple, room-temperature processing methods, electrochromic polymers have attracted attention as active materials for flexible, low-power-consuming devices. However, slow switching speeds in devices realized to date, as well as the complexity of having to combine several distinct polymers to achieve a full-colour gamut, have limited electrochromic materials to niche applications. Here we achieve fast, high-contrast electrochromic switching by significantly enhancing the interaction of light—propagating as deep-subwavelength-confined surface plasmon polaritons through arrays of metallic nanoslits, with an electrochromic polymer—present as an ultra-thin coating on the slit sidewalls. The switchable configuration retains the short temporal charge-diffusion characteristics of thinmore » electrochromic films, while maintaining the high optical contrast associated with thicker electrochromic coatings. In conclusion, we further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-colour response with high contrast and fast switching speeds, while relying on just one electrochromic polymer.« less

  19. Electrochromic nickel oxide simultaneously doped with lithium and a metal dopant

    SciTech Connect

    Gillaspie, Dane T; Weir, Douglas G

    2014-04-01

    An electrochromic device comprising a counter electrode layer comprised of lithium metal oxide which provides a high transmission in the fully intercalated state and which is capable of long-term stability, is disclosed. Methods of making an electrochromic device comprising such a counter electrode are also disclosed.

  20. High-contrast and fast electrochromic switching enabled by plasmonics

    NASA Astrophysics Data System (ADS)

    Talin, Albert; Xu, Ting; Walter, Erich; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri

    With vibrant colors and simple, room-temperature processing methods, electrochromic polymers have long attracted attention as active materials for flexible, low-power consuming devices such as smart windows and displays. However, despite their many advantages, slow switching speed and complexity of combining several separate polymers to achieve full-color gamut has limited electrochromic materials to niche applications. Here we exploit the enhanced light-matter interaction associated with the deep-subwavelength mode confinement of surface plasmon polaritons propagating in metallic nanoslit arrays coated with ultra-thin electrochromic polymers to build a novel configuration for achieving high-contrast and fast electrochromic switching. The switchable configuration retains the short temporal charge-diffusion characteristics of thin electrochromic films while maintaining the high optical-contrast associated with thicker electrochromic coatings. We further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-color response with high-contrast and fast switching-speeds while relying on just one electrochromic polymer.

  1. Application issues for large-area electrochromic windows incommercial buildings

    SciTech Connect

    Lee, Eleanor S.; DiBartolomeo, D.L.

    2000-05-01

    Projections of performance from small-area devices to large-area windows and enterprise marketing have created high expectations for electrochromic glazings. As a result, this paper seeks to precipitate an objective dialog between material scientists and building-application scientists to determine whether actual large-area electrochromic devices will result in significant performance benefits and what material improvements are needed, if any, to make electrochromics more practical for commercial building applications. Few in-situ tests have been conducted with large-area electrochromic windows applied in buildings. This study presents monitored results from a full-scale field test of large-area electrochromic windows to illustrate how this technology will perform in commercial buildings. The visible transmittance (Tv) of the installed electrochromic ranged from 0.11 to 0.38. The data are limited to the winter period for a south-east-facing window. The effect of actual device performance on lighting energy use, direct sun control, discomfort glare, and interior illumination is discussed. No mechanical system loads were monitored. These data demonstrate the use of electrochromics in a moderate climate and focus on the most restrictive visual task: computer use in offices. Through this small demonstration, we were able to determine that electrochromic windows can indeed provide unmitigated transparent views and a level of dynamic illumination control never before seen in architectural glazing materials. Daily lighting energy use was 6-24 percent less compared to the 11 percent-glazing, with improved interior brightness levels. Daily lighting energy use was 3 percent less to 13 percent more compared to the 38 percent-glazing, with improved window brightness control. The electrochromic window may not be able to fulfill both energy-efficiency and visual comfort objectives when low winter direct sun is present, particularly for computer tasks using cathode-ray tube (CRT

  2. Large-scale fabrication of pseudocapacitive glass windows that combine electrochromism and energy storage.

    PubMed

    Yang, Peihua; Sun, Peng; Chai, Zhisheng; Huang, Langhuan; Cai, Xiang; Tan, Shaozao; Song, Jinhui; Mai, Wenjie

    2014-10-27

    Multifunctional glass windows that combine energy storage and electrochromism have been obtained by facile thermal evaporation and electrodeposition methods. For example, WO3 films that had been deposited on fluorine-doped tin oxide (FTO) glass exhibited a high specific capacitance of 639.8 F g(-1). Their color changed from transparent to deep blue with an abrupt decrease in optical transmittance from 91.3% to 15.1% at a wavelength of 633 nm when a voltage of -0.6 V (vs. Ag/AgCl) was applied, demonstrating its excellent energy-storage and electrochromism properties. As a second example, a polyaniline-based pseudocapacitive glass was also developed, and its color can change from green to blue. A large-scale pseudocapacitive WO3-based glass window (15×15 cm(2)) was fabricated as a prototype. Such smart pseudocapacitive glass windows show great potential in functioning as electrochromic windows and concurrently powering electronic devices, such as mobile phones or laptops. PMID:25212514

  3. Solid state electrochromic smart windows

    NASA Astrophysics Data System (ADS)

    1991-03-01

    The structure under development at EIC Laboratories consists of a multilayer stack of thin films, incorporating the two principal electrochemically active elements, the electrochromic (EC) and counter electrode (CE) layers, respectively. The EC layer changes from colorless to a state of reduced transmission on reduction while the CE layer has the opposite (complementary) behavior (or is colorless in both oxidized and reduced states). These are separated by an ion conducting electrolyte. The stack is completed with top and bottom transparent electrodes. The major achievements are as follows: (1) Tunable thermal emittance for the EC layer over a range of 0.2 to 0.8 was demonstrated, indicating the feasibility of surfaces with adjustable heat transfer properties. (2) Thin film ion conductors based on the Li2O/B2O3 and LiNbO3 were developed using thermal and electron beam evaporation with ionic conductivities greater than 10(exp -8) S/cm, fulfilling a major requirement for this component. (3) A variety of improved vanadium oxide-based counter electrode materials were demonstrated and patented which undergo reversible electrochemical Li insertion reactions and which increase their solar transmission on reduction. (4) Devices incorporating a laminated Li+ conducting polymer electrolyte were demonstrated with bleached state visible transmittance of greater than 65 percent and colored state transmittance of less than 15 percent. These devices were tested for greater than 10(exp 4) complete cycles. (5) An all thin film solid state device was demonstrated with a visible transmission range of 65/13 percent, using the component materials developed on this program. The device was tested for greater than 3000 complete cycles without degradation. A fabrication sequence was specified which forms the basis of initial production cost estimates. (6) Window modeling studies have been used to compare the relative performance of amorphous and crystalline WO3-based electrochromic

  4. Electrochromic window with high reflectivity modulation

    SciTech Connect

    Goldner, R.B.; Gerouki, A.; Liu, T.Y.; Goldner, M.A.; Haas, T.E.

    2000-07-25

    A multi-layered, active, thin film, solid-state electrochromic device having a high reflectivity in the near infrared in a colored state, a high reflectivity and transmissivity modulation when switching between colored and bleached states, a low absorptivity in the near infrared, and fast switching times, and methods for its manufacture and switching are provided. In one embodiment, a multi-layered device comprising a first indium tin oxide transparent electronic conductor, a transparent ion blocking layer, a tungsten oxide electrochromic anode, a lithium ion conducting-electrically resistive electrolyte, a complimentary lithium mixed metal oxide electrochromic cathode, a transparent ohmic contact layer, a second indium oxide transparent electronic conductor, and a silicon nitride encapsulant is provided. Through elimination of optional intermediate layers, simplified device designs are provided as alternative embodiments. Typical colored-state reflectivity of the multi-layered device is greater than 50% in the near infrared, bleached-state reflectivity is less than 40% in the visible, bleached-state transmissivity is greater than 60% in the near infrared and greater than 40% in the visible, and spectral absorbance is less than 50% in the range from 0.65-2.5 mum.

  5. Electrochromic window with high reflectivity modulation

    DOEpatents

    Goldner, Ronald B.; Gerouki, Alexandra; Liu, Te-Yang; Goldner, Mark A.; Haas, Terry E.

    2000-01-01

    A multi-layered, active, thin film, solid-state electrochromic device having a high reflectivity in the near infrared in a colored state, a high reflectivity and transmissivity modulation when switching between colored and bleached states, a low absorptivity in the near infrared, and fast switching times, and methods for its manufacture and switching are provided. In one embodiment, a multi-layered device comprising a first indium tin oxide transparent electronic conductor, a transparent ion blocking layer, a tungsten oxide electrochromic anode, a lithium ion conducting-electrically resistive electrolyte, a complimentary lithium mixed metal oxide electrochromic cathode, a transparent ohmic contact layer, a second indium oxide transparent electronic conductor, and a silicon nitride encapsulant is provided. Through elimination of optional intermediate layers, simplified device designs are provided as alternative embodiments. Typical colored-state reflectivity of the multi-layered device is greater than 50% in the near infrared, bleached-state reflectivity is less than 40% in the visible, bleached-state transmissivity is greater than 60% in the near infrared and greater than 40% in the visible, and spectral absorbance is less than 50% in the range from 0.65-2.5 .mu.m.

  6. A wide-gap a-SiC:H PV-powered electrochromic window coating

    SciTech Connect

    Gao, W.; Lee, S.H.; Xu, Y.; Benson, D.K.; Deb, S.K.; Branz, H.M.

    1998-09-01

    The authors report on the first monolithic, amorphous-silicon-based, photovoltaic-powered electrochromic window coating. The coating employs a wide bandgap a-Si{sub 1{minus}x}C{sub x}:H n-i-p photovoltaic (PV) cell as a semitransparent power supply, and a Li{sub y}WO{sub 3}/LiAlF{sub 4}/V{sub 2}O{sub 5} electrochromic (EC) device as an optical-transmittance modulator. The EC device is deposited directly on top of a PV cell that coats a glass substrate. The a-Si{sub 1{minus}x}C{sub x}:H PV cell has a Tauc gap of 2.2 eV and a transmittance of 60--80% over a large portion of the visible light spectrum. The authors reduced the thickness of the device to about 600 {angstrom} while maintaining a 1-sun open-circuit voltage of 0.9 V and short-circuit current of 2 mA/cm{sup 2}. The prototype 16 cm{sup 2} PV/EC device modulates the transmittance by more than 60% over a large portion of the visible spectrum. The coloring and bleaching times of the EC device are approximately 1 minute under normal operating conditions ({+-} 1 volt). A brief description of photoelectrochromic windows study is also given.

  7. Electrochromic sun control coverings for windows

    SciTech Connect

    Benson, D K; Tracy, C E

    1990-04-01

    The 2 billion square meters (m{sup 2}) of building windows in the United States cause a national energy drain almost as large as the energy supply of the Alaskan oil pipeline. Unlike the pipeline, the drain of energy through windows will continue well into the 21st century. A part of this energy drain is due to unwanted sun gain through windows. This is a problem throughout the country in commercial buildings because they generally require air conditioning even in cold climates. New commercial windows create an additional 1600 MW demand for peak electric power in the United States each year. Sun control films, widely used in new windows and as retrofits to old windows, help to mitigate this problem. However, conventional, static solar control films also block sunlight when it is wanted for warmth and daylighting. New electrochromic, switchable, sun-gain-control films now under development will provide more nearly optimal and automatic sun control for added comfort, decreased building operating expense, and greater energy saving. Switchable, electrochromic films can be deposited on polymers at high speeds by plasma enhanced chemical vapor deposition (PECVD) in a process that may be suitable for roll coating. This paper describes the electrochromic coatings and the PECVD processes, and speculates about their adaptability to high-speed roll coating. 8 refs., 3 figs.

  8. Surface conditioning of fusion devices plasma assisted thin film deposition

    SciTech Connect

    Winter, J.; Waelbroeck, F.; Weinhold, P.; Esser, H.G.; von Seggern, J.; Philipps, V.; Vietzke, E. )

    1990-02-05

    Conditioning of the plasma facing surfaces of a fusion device is a necessary prerequisite for the generaton of pure, hot and stable fusion plasmas. Thin layers of carbon or of boron containing carbon deposited plasmachemically on the entire inner surfaces of a tokamak have proven to be a very effective technique for wall prehandling.

  9. Multiplexed electrospray deposition for protein microarray with micromachined silicon device

    NASA Astrophysics Data System (ADS)

    Bhatnagar, Parijat

    2007-07-01

    Multiplexed electrospray deposition device capable of delivering picoliter volumes made by silicon micromachining technology has been developed as a deposition tool for making protein microarrays in a noncontact mode. Upon application of potential difference in the range of 7-9kV, biomolecules dissolved in suitable buffer with nonionic surfactant and loaded on the electrospray tips were dispensed on the substrate with microfabricated hydrogel features (1-10μm) in cone-jet mode. Schiff base chemistry followed by reductive amination was utilized for covalent immobilization.

  10. Polyaniline as a reversibly switchable electrochromic material. (Reannouncement with new availability information). Technical report

    SciTech Connect

    Shieh, W.R.; Yang, S.C.; Marzzacco, C.; Hwang, J.H.

    1990-12-31

    Polyaniline is an interesting electrochromic material because its color can be changed from clear to green, to blue, and to purple by electrochemical oxidation. The structural transformations associated with these color changes are shown. One of the possible applications for polyaniline is to use it as the active material in electrochromic windows. An electrochromic window is a multi-layered device with the structure of a transparent rechargeable battery. A practical electrochromic window needs to have long color-cycling lifetime and good durability under solar radiation. This is a severe requirement because all layers of materials and interfaces between layers have to be durable under such electrochemical and photochemical stress. In this communication the authors report an initial study towards the construction of a polyaniline-based electrochromic window. They concerned themselves with only polyaniline coated on tin oxide glass. They tested such a half-cell in an aqueous electrolyte to see if this part of the electrochromic device can be made durable enough for electrochromic applications and to find useful designing principles for constructing good devices.

  11. Electrochromic & magnetic properties of electrode materials for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zheng-Fei, Guo; Kun, Pan; Xue-Jin, Wang

    2016-01-01

    Progress in electrochromic lithium ion batteries (LIBs) is reviewed, highlighting advances and possible research directions. Methods for using the LIB electrode materials’ magnetic properties are also described, using several examples. Li4Ti5O12 (LTO) film is discussed as an electrochromic material and insertion compound. The opto-electrical properties of the LTO film have been characterized by electrical measurements and UV-Vis spectra. A prototype bi-functional electrochromic LIB, incorporating LTO as both electrochromic layer and anode, has also been characterized by charge- discharge measurements and UV-Vis transmittance. The results show that the bi-functional electrochromic LIB prototype works well. Magnetic measurement has proven to be a powerful tool to evaluate the quality of electrode materials. We introduce briefly the magnetism of solids in general, and then discuss the magnetic characteristics of layered oxides, spinel oxides, olivine phosphate LiFePO4, and Nasicon-type Li3Fe2(PO4)3. We also discuss what kind of impurities can be detected, which will guide us to fabricate high quality films and high performance devices. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA034201) and the Chinese Universities Scientific Fund (Grant No. 2015LX002).

  12. Deposition of device quality low H content, amorphous silicon films

    DOEpatents

    Mahan, A.H.; Carapella, J.C.; Gallagher, A.C.

    1995-03-14

    A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH{sub 4}) over a high temperature, 2,000 C, tungsten (W) filament in the proximity of a high temperature, 400 C, substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20--30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content. 7 figs.

  13. Deposition of device quality low H content, amorphous silicon films

    DOEpatents

    Mahan, Archie H.; Carapella, Jeffrey C.; Gallagher, Alan C.

    1995-01-01

    A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH.sub.4) over a high temperature, 2000.degree. C., tungsten (W) filament in the proximity of a high temperature, 400.degree. C., substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20-30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content.

  14. Electrochromic properties of tungsten-titanium oxide films.

    PubMed

    Chen, Ya-Chi; Lin, Tai-Nan; Chen, Tien-Lai; Li, Yun-Da; Weng, Ko-Wei

    2012-02-01

    The last decade has seen great in electrochromic (EC) technology for smart windows and displays. In this study, WTiOx films formed from TiO2 and WO3 were deposited onto ITO glass with a sheet resistance of 10 Omega cm and on silicon substrates, by pulsed magnetron sputtering using a W and Ti alloy target. The films were deposited at plasma powers 100, 200, 300, 400 and 500 W using a gaseous Ar (150 sccm)/O2 (50 sccm) mixture; the working pressure was fixed at 5E-2 torr. The film thickness increased with the plasma power. However, increasing the plasma power yielded a more crystalline structure with poorer electrochromic properties. The influence of Ti doping and plasma power on the structural, optical and electrochromic properties of the WTiOx thin films was studied. WTiOx films grown at various plasma powers of under 400 W were amorphous. Deposition of films at 400 W yielded the optimal electrochromic properties, with high optical modulation, high coloration efficiency and the lowest color memory effect at wavelengths 400, 550 and 800 nm. An XPS study indicated that Ti can stabilize the valence state of W6+. The improvements caused by the doping with Ti were tested: an optical density (OD) of close to 0.85 and a maximum delta T (%) at 400 nm of 25.8%, at 550 nm of 52.5% and at 800 nm (in the near-IR region) of 62.4%. PMID:22629942

  15. From beads-to-wires-to-fibers of tungsten oxide: electrochromic response

    NASA Astrophysics Data System (ADS)

    Kadam, P. M.; Tarwal, N. L.; Shinde, P. S.; Patil, R. S.; Deshmukh, H. P.; Patil, P. S.

    2009-11-01

    Suitable host lattice and morphology for easy intercalation and deintercalation process are crucial requirements for electrochromic device. In this investigation, the evolution of structural and morphological changes and their effect on electrochromic (EC) properties of spray-deposited WO3 thin films are studied. Films of different morphologies were deposited from an ammonium tungstate precursor solution using a novel pulsed spray pyrolysis technique (PSPT) on tin-doped indium oxide (ITO) coated glass substrates by varying quantity of spraying solution. Interesting morphological transition from beads-to-wires-to-fibers as a function of quantity of sprayed solution has been demonstrated. The porosity, crystallinity and “open” structures in the films consisting of beads, wires, and fiber-like morphology enabled us to correlate these aspects to their EC performance. WO3 films comprising wire-like morphology (20 cc spraying quantity) exhibited better EC properties both in terms of coloration efficiency (42.7 cm2/C) and electrochemical stability (103 colored/bleached cycles) owing to their adequate open structure, porosity, and amorphicity, compared with the films having bead/fiber-like morphology.

  16. Subject Responses to Electrochromic Windows

    SciTech Connect

    Clear, Robert; Inkarojrit, Vorapat; Lee, Eleanor

    2006-03-03

    Forty-three subjects worked in a private office with switchable electrochromic windows, manually-operated Venetian blinds, and dimmable fluorescent lights. The electrochromic window had a visible transmittance range of approximately 3-60%. Analysis of subject responses and physical data collected during the work sessions showed that the electrochromic windows reduced the incidence of glare compared to working under a fixed transmittance (60%) condition. Subjects used the Venetian blinds less often and preferred the variable transmittance condition, but used slightly more electric lighting with it than they did when window transmittance was fixed.

  17. Electrochromic and spectroelectrochemical properties of novel 4,4‧-bipyridilium-TCNQ anion radical complexes

    NASA Astrophysics Data System (ADS)

    Wang, Guoming; Fu, Xiangkai; Deng, Jun; Huang, Xuemei; Miao, Qiang

    2013-07-01

    Three novel electrochromic materials 7,7,8,8-tetracyanoquinodimethane (TCNQ) anion radical salts with substituted 4,4'-bipyridilium derivatives (monosubstituent-4,4'-bipyridilium) were prepared. The structure of the complexes was characterized by Elemental analyses, Solid IR spectra and UV-vis spectroscopy. The electrochromic behaviors and electrooptical properties of the complexes were investigated by cyclic voltammetry and UV-vis absorption spectra. Electrochromic devices based on monosubstituent 4,4'-bipyridilium-TCNQ anion radical salts (abbreviated as MBTS) were fabricated which exhibited green-magenta color change. Their color reversibility was excellent with high color-change efficiency after 1000 cycles of the transmittance and transmittance change.

  18. Electrochromic Variable-Emissivity Surfaces

    NASA Technical Reports Server (NTRS)

    Rauh, R. David; Cogan, Stuart F.

    1988-01-01

    Temperature controlled by altering infrared radiative properties. Infrared emissivity of electrochromically active layer changed by applying voltage to insert or remove Li atoms electrochemically. Change reversible and continuously variable between specified limits of layered structure.

  19. Stand-alone photovoltaic (PV) powered electrochromic window

    DOEpatents

    Benson, David K.; Crandall, Richard S.; Deb, Satyendra K.; Stone, Jack L.

    1995-01-01

    A variable transmittance double pane window includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. A battery is placed in a parallel fashion to the array of photovoltaic cells to allow the user the ability to manually override the system when a desired transmittance is desired.

  20. Stand-alone photovoltaic (PV) powered electrochromic window

    DOEpatents

    Benson, D.K.; Crandall, R.S.; Deb, S.K.; Stone, J.L.

    1995-01-24

    A variable transmittance double pane window includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. A battery is placed in a parallel fashion to the array of photovoltaic cells to allow the user the ability to manually override the system when a desired transmittance is desired. 11 figures.

  1. Electrochromic properties of niobium oxide thin films prepared by radio-frequency magnetron sputtering method

    NASA Astrophysics Data System (ADS)

    Maruyama, Toshiro; Arai, Susumu

    1993-08-01

    Electrochromic niobium oxide thin films were prepared by a radio-frequency magnetron sputtering method. Amorphous Nb2O5 thin films deposited at radio-frequency power 100 W showed the electrochromic behavior: Reduction and oxidation of the films in 0.1 M Na2CO3+0.1 M NaHCO3 buffer solution resulted in coloration and bleaching, respectively. Coulometry indicated that the coloration efficiency was 10 cm2/C.

  2. Characterization of calcified deposits on contraceptive intrauterine devices.

    PubMed

    Patai, K; Berényi, M; Sipos, M; Noszál, B

    1998-11-01

    The formation of calcified deposits on > 200 contraceptive intrauterine devices (IUD) was quantitated as a function of time in healthy women, pregnant women, and women with a pathologic lesion. The incrustment formation was significantly enhanced when inflammation occurred, but change could not be observed in cases of pregnancy. The incrustments were analyzed by x-ray diffraction, infrared spectroscopy, x-ray microprobe, and ultramicrochemical stone analysis techniques. Major components and their average w/w percent quantities in the incrustments are as follows: calcium carbonate 75%, apatite 5%, and organic matrix 20%. Earlier hypotheses on the chemical processes of deposit formation are discussed, and a new, ionic mechanism of calcification on IUD surfaces is suggested.

  3. A Naphthalenediimide-Based Metal-Organic Framework and Thin Film Exhibiting Photochromic and Electrochromic Properties.

    PubMed

    Xie, Yi-Xin; Zhao, Wen-Na; Li, Guo-Chang; Liu, Peng-Fei; Han, Lei

    2016-01-19

    A multifunctional metal-organic framework, NBU-3, has been explored as a 2D three-connected network based on a naphthalenediimide-based ligand. The NBU-3 crystals display photochromic properties, and NBU-3 thin films on FTO substrates exhibit electrochromic properties. NBU-3 is the first example of MOF materials containing both photochromic and electrochromic properties, which can be desirable for thin film devices. PMID:26713454

  4. Large-Scale Graphene Film Deposition for Monolithic Device Fabrication

    NASA Astrophysics Data System (ADS)

    Al-shurman, Khaled

    Since 1958, the concept of integrated circuit (IC) has achieved great technological developments and helped in shrinking electronic devices. Nowadays, an IC consists of more than a million of compacted transistors. The majority of current ICs use silicon as a semiconductor material. According to Moore's law, the number of transistors built-in on a microchip can be double every two years. However, silicon device manufacturing reaches its physical limits. To explain, there is a new trend to shrinking circuitry to seven nanometers where a lot of unknown quantum effects such as tunneling effect can not be controlled. Hence, there is an urgent need for a new platform material to replace Si. Graphene is considered a promising material with enormous potential applications in many electronic and optoelectronics devices due to its superior properties. There are several techniques to produce graphene films. Among these techniques, chemical vapor deposition (CVD) offers a very convenient method to fabricate films for large-scale graphene films. Though CVD method is suitable for large area growth of graphene, the need for transferring a graphene film to silicon-based substrates is required. Furthermore, the graphene films thus achieved are, in fact, not single crystalline. Also, graphene fabrication utilizing Cu and Ni at high growth temperature contaminates the substrate that holds Si CMOS circuitry and CVD chamber as well. So, lowering the deposition temperature is another technological milestone for the successful adoption of graphene in integrated circuits fabrication. In this research, direct large-scale graphene film fabrication on silicon based platform (i.e. SiO2 and Si3N4) at low temperature was achieved. With a focus on low-temperature graphene growth, hot-filament chemical vapor deposition (HF-CVD) was utilized to synthesize graphene film using 200 nm thick nickel film. Raman spectroscopy was utilized to examine graphene formation on the bottom side of the Ni film

  5. Electrochemically Polymerized Heterocycles As Electrochromic Materials

    NASA Astrophysics Data System (ADS)

    Gazard, M.

    1983-09-01

    The electrochromic properties of thin films prepared by electropolymerization of pyrrole and 2,2' bithiophene are described. The films change color reversibly when they are electrochemically cycled. The response times are less than 150 ms and the stability under repetitive cycling is good (105 cycles). The electrochromic parameters are compared to those of other electrochromic polymers.

  6. Nanostructured electrochromic smart windows: traditional materials and NIR-selective plasmonic nanocrystals

    SciTech Connect

    Runnerstrom, EL; Llordes, A; Lounis, SD; Milliron, DJ

    2014-06-04

    Electrochromic devices, which dynamically change colour under applied potential, are widely studied for use in energy-efficient smart windows. To improve the viability of smart windows, many researchers are utilizing nanomaterials, which can provide electrochromic devices with improved colouration efficiencies, faster switching times, longer cycle lives, and potentially reduced costs. In an effort to demonstrate a new type of electrochromic device that goes beyond the capabilities of commonly used electrochromic materials, researchers have turned to plasmonic transparent conductive oxide (TCO) nanocrystals. Electrochemical injection of electrons into plasmonic TCO nanocrystal films induces a shift in the plasmon frequency and gives rise to the new functionality of selective optical modulation in the near-infrared region of the solar spectrum. These nanocrystals can be used as building blocks to enable creation of advanced electrochromic devices containing mesoporous electrodes or nanocrystal-in-glass composites. Such devices have been important in advancing the field towards achieving the ideal smart window with independent control over visible and NIR transmittance.

  7. Nanostructured electrochromic smart windows: traditional materials and NIR-selective plasmonic nanocrystals.

    PubMed

    Runnerstrom, Evan L; Llordés, Anna; Lounis, Sebastien D; Milliron, Delia J

    2014-09-21

    Electrochromic devices, which dynamically change colour under applied potential, are widely studied for use in energy-efficient smart windows. To improve the viability of smart windows, many researchers are utilizing nanomaterials, which can provide electrochromic devices with improved colouration efficiencies, faster switching times, longer cycle lives, and potentially reduced costs. In an effort to demonstrate a new type of electrochromic device that goes beyond the capabilities of commonly used electrochromic materials, researchers have turned to plasmonic transparent conductive oxide (TCO) nanocrystals. Electrochemical injection of electrons into plasmonic TCO nanocrystal films induces a shift in the plasmon frequency and gives rise to the new functionality of selective optical modulation in the near-infrared region of the solar spectrum. These nanocrystals can be used as building blocks to enable creation of advanced electrochromic devices containing mesoporous electrodes or nanocrystal-in-glass composites. Such devices have been important in advancing the field towards achieving the ideal smart window with independent control over visible and NIR transmittance. PMID:24935022

  8. Electrochromic Graphene Molecules

    DOE PAGESBeta

    Ji, Zhiqiang; Doorn, Stephen K.; Sykora, Milan

    2015-03-13

    Polyclic aromatic hydrocarbons, also called Graphene Molecules (GMs), with chemical composition C132H36(COOH)2 were synthesized in-situ on the surface of transparent nanocrystaline indium tin oxide (nc-ITO) electrodes. Their electronic structure was studied electrochemically and spectro-electrochemically. Variations in the potential applied onto the nc-ITO/GM electrodes induce only small changes in the observed current but they produce dramatic changes in the absorption of the GMs, which are associated with their oxidation and reduction. Analysis of the absorption changes using modified Nernst equation is used to determine standard potentials associated with the individual charge transfer processes. For the GMs prepared here these were foundmore » to be E1,ox 0 = 0.77± 0.01 V and E2,ox 0 = 1.24 ± 0.02 V vs. NHE for the first and second oxidation and E1,red 0 = -1.50 ± 0.04 V for the first reduction. The charge transfer processes are found to be non-ideal. The non-ideality factors associated with the oxidation and reduction processes suggest presence of strong interactions between the GM redox centers. Under the conditions of potential cycling GMs show rapid (seconds) color change with high contrast and stability. An electrochromic application is demonstrated wherein the GMs are used as the optically active component.« less

  9. Low-Cost Flexible Electrochromic Film for Energy Efficient Buildings

    SciTech Connect

    2010-01-01

    Broad Funding Opportunity Announcement Project: ITN is addressing the high cost of electrochromic windows with a new manufacturing process: roll-to-roll deposition of the film onto flexible plastic surfaces. Production of electrochromic films on plastic requires low processing temperatures and uniform film quality over large surface areas. ITN is overcoming these challenges using its previous experience in growing flexible thin-film solar cells and batteries. By developing sensor-based controls, ITN’s roll-to-roll manufacturing process yields more film over a larger area than traditional film deposition methods. Evaluating deposition processes from a control standpoint ultimately strengthens the ability for ITN to handle unanticipated deviations quickly and efficiently, enabling more consistent large-volume production. The team is currently moving from small-scale prototypes into pilot-scale production to validate roll-to-roll manufacturability and produce scaled prototypes that can be proven in simulated operating conditions. Electrochromic plastic films could also open new markets in building retrofit applications, vastly expanding the potential energy savings.

  10. Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption

    NASA Astrophysics Data System (ADS)

    Metts, Jonathan Glen

    Water consumption for space suit thermal control is a limiting factor on long-term space exploration missions. A concept is proposed for an integrated, flexible suit radiator using infrared electrochromic materials for modulated heat rejection from the suit. Properties of electrochromic materials, the structure of electrochromic devices, and relevant heat transfer processes are presented as background information. Analytical methods are employed to bound theoretical performance and determine required emissivity ranges for lunar surface operations. Case studies are presented incorporating Apollo program and Advanced Walkback Test metabolic and environmental data to estimate sublimator water consumption and hypothetical water savings with the electrochromic radiator. Concepts are presented and analyzed for integrating an electrochromic radiator with existing and future space suit designs. A preliminary systems-level trade analysis is performed with the Equivalent System Mass metric used to compare this technology with the legacy sublimator and other extravehicular activity cooling technologies in development. Experimental objectives, procedures, and results are presented for both bench-top and thermal vacuum testing of electrochromic radiator materials.

  11. Electrochromic Graphene Molecules

    SciTech Connect

    Ji, Zhiqiang; Doorn, Stephen K.; Sykora, Milan

    2015-03-13

    Polyclic aromatic hydrocarbons, also called Graphene Molecules (GMs), with chemical composition C132H36(COOH)2 were synthesized in-situ on the surface of transparent nanocrystaline indium tin oxide (nc-ITO) electrodes. Their electronic structure was studied electrochemically and spectro-electrochemically. Variations in the potential applied onto the nc-ITO/GM electrodes induce only small changes in the observed current but they produce dramatic changes in the absorption of the GMs, which are associated with their oxidation and reduction. Analysis of the absorption changes using modified Nernst equation is used to determine standard potentials associated with the individual charge transfer processes. For the GMs prepared here these were found to be E1,ox 0 = 0.77± 0.01 V and E2,ox 0 = 1.24 ± 0.02 V vs. NHE for the first and second oxidation and E1,red 0 = -1.50 ± 0.04 V for the first reduction. The charge transfer processes are found to be non-ideal. The non-ideality factors associated with the oxidation and reduction processes suggest presence of strong interactions between the GM redox centers. Under the conditions of potential cycling GMs show rapid (seconds) color change with high contrast and stability. An electrochromic application is demonstrated wherein the GMs are used as the optically active component.

  12. Surfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, toward electrochromic applications

    NASA Astrophysics Data System (ADS)

    Denayer, Jessica; Bister, Geoffroy; Simonis, Priscilla; Colson, Pierre; Maho, Anthony; Aubry, Philippe; Vertruyen, Bénédicte; Henrist, Catherine; Lardot, Véronique; Cambier, Francis; Cloots, Rudi

    2014-12-01

    Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics.

  13. Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films

    NASA Astrophysics Data System (ADS)

    Wen, Rui-Tao; Granqvist, Claes G.; Niklasson, Gunnar A.

    2015-10-01

    There is keen interest in the use of amorphous WO3 thin films as cathodic electrodes in transmittance-modulating electrochromic devices. However, these films suffer from ion-trapping-induced degradation of optical modulation and reversibility on extended Li+-ion exchange. Here, we demonstrate that ion-trapping-induced degradation, which is commonly believed to be irreversible, can be successfully eliminated by constant-current-driven de-trapping; that is, WO3 films can be rejuvenated and regain their initial highly reversible electrochromic performance. Pronounced ion trapping occurs when x exceeds ~0.65 in LixWO3 during ion insertion. We find two main kinds of Li+-ion-trapping site (intermediate and deep) in WO3, where the intermediate ones are most prevalent. Li+ ions can be completely removed from intermediate traps but are irreversibly bound in deep traps. Our results provide a general framework for developing and designing superior electrochromic materials and devices.

  14. High Frequency Dielectric Characteristics of Electrochromic, WO3 and NiO Films with LiNbO3 Electrolyte.

    PubMed

    Bulja, S; Kopf, R; Tate, A; Hu, T

    2016-01-01

    A great deal of attention has been recently focused on Electrochromic (EC) materials and EC based devices, promoting mainly applications related to display technology. In this case, EC based displays are usually actuated by the application of low dc bias voltages, changing their appearance from transparent to opaque. A variety of studies related to the optical characteristics of EC materials have been reported, however, no serious studies so far have been reported on the possible high frequency tunability of the dielectric characteristics of these materials, with the exception of the work by Rose, which presented the operation of a microwave shutter based on conductive polymers operating in the X-band. Here we report tuneable high frequency dielectric characteristics of an Electrochromic (EC) cell with a complimentary structure of Conductor/WO3/LiNbO3/NiO/Conductor in the frequency range from 1 GHz to 20 GHz. The EC cell was prepared using standard semiconductor processing technology, such as lithography, etch and deposition techniques. Our measured results indicate that tunability of high frequency dielectric characteristics as a function of dc bias voltage is achieved, and that a possibility exists for this tunability to be tailored. PMID:27357480

  15. High Frequency Dielectric Characteristics of Electrochromic, WO3 and NiO Films with LiNbO3 Electrolyte

    NASA Astrophysics Data System (ADS)

    Bulja, S.; Kopf, R.; Tate, A.; Hu, T.

    2016-06-01

    A great deal of attention has been recently focused on Electrochromic (EC) materials and EC based devices, promoting mainly applications related to display technology. In this case, EC based displays are usually actuated by the application of low dc bias voltages, changing their appearance from transparent to opaque. A variety of studies related to the optical characteristics of EC materials have been reported, however, no serious studies so far have been reported on the possible high frequency tunability of the dielectric characteristics of these materials, with the exception of the work by Rose, which presented the operation of a microwave shutter based on conductive polymers operating in the X-band. Here we report tuneable high frequency dielectric characteristics of an Electrochromic (EC) cell with a complimentary structure of Conductor/WO3/LiNbO3/NiO/Conductor in the frequency range from 1 GHz to 20 GHz. The EC cell was prepared using standard semiconductor processing technology, such as lithography, etch and deposition techniques. Our measured results indicate that tunability of high frequency dielectric characteristics as a function of dc bias voltage is achieved, and that a possibility exists for this tunability to be tailored.

  16. High Frequency Dielectric Characteristics of Electrochromic, WO3 and NiO Films with LiNbO3 Electrolyte

    PubMed Central

    Bulja, S.; Kopf, R.; Tate, A.; Hu, T.

    2016-01-01

    A great deal of attention has been recently focused on Electrochromic (EC) materials and EC based devices, promoting mainly applications related to display technology. In this case, EC based displays are usually actuated by the application of low dc bias voltages, changing their appearance from transparent to opaque. A variety of studies related to the optical characteristics of EC materials have been reported, however, no serious studies so far have been reported on the possible high frequency tunability of the dielectric characteristics of these materials, with the exception of the work by Rose, which presented the operation of a microwave shutter based on conductive polymers operating in the X-band. Here we report tuneable high frequency dielectric characteristics of an Electrochromic (EC) cell with a complimentary structure of Conductor/WO3/LiNbO3/NiO/Conductor in the frequency range from 1 GHz to 20 GHz. The EC cell was prepared using standard semiconductor processing technology, such as lithography, etch and deposition techniques. Our measured results indicate that tunability of high frequency dielectric characteristics as a function of dc bias voltage is achieved, and that a possibility exists for this tunability to be tailored. PMID:27357480

  17. Effect of focused ion beam deposition induced contamination on the transport properties of nano devices.

    PubMed

    Lan, Yann-Wen; Chang, Wen-Hao; Chang, Yuan-Chih; Chang, Chia-Seng; Chen, Chii-Dong

    2015-02-01

    Focused ion beam (FIB) deposition produces unwanted particle contamination beyond the deposition point. This is due to the FIB having a Gaussian distribution. This work investigates the spatial extent of this contamination and its influence on the electrical properties of nano-electronic devices. A correlation study is performed on carbon-nanotube (CNT) devices manufactured using FIB deposition. The devices are observed using transmission electron microscopy (TEM) and these images are correlated with device electrical characteristics. To discover how far Pt-nanoparticle contamination occurs along a CNT after FIB electrical contact deposition careful TEM inspections are performed. The results show FIB deposition efficiently improves electrical contact; however, the practice is accompanied by serious particle contamination near deposition points. These contaminants include metal particles and amorphous elements originating from precursor gases and residual water molecules in the vacuum chamber. Pt-contamination extends for approximately 2 μm from the point of FIB contact deposition. These contaminants cause current fluctuations and alter the transport characteristics of devices. It is recommended that nano-device fabrication occurs at a distance greater than 2 μm from the FIB deposition of an electrical contact.

  18. Electrochromic fiber-shaped supercapacitors.

    PubMed

    Chen, Xuli; Lin, Huijuan; Deng, Jue; Zhang, Ye; Sun, Xuemei; Chen, Peining; Fang, Xin; Zhang, Zhitao; Guan, Guozhen; Peng, Huisheng

    2014-12-23

    An electrochromic fiber-shaped super-capacitor is developed by winding aligned carbon nanotube/polyaniline composite sheets on an elastic fiber. The fiber-shaped supercapacitors demonstrate rapid and reversible chromatic transitions under different working states, which can be directly observed by the naked eye. They are also stretchable and flexible, and are woven into textiles to display designed signals in addition to storing energy.

  19. Pulmonary deposition of aerosols by different mechanical devices.

    PubMed

    Matthys, H; Köhler, D

    1985-01-01

    With a new method for easy labeling of beta 2-agonists we measured intra- and extrapulmonary aerosol deposition after the administration of a bolus from a metered-dose inhaler at residual volume (RV) inhaling after a pause of 2 s and after immediate administration into the inspiratory flow at functional residual capacity (FRC). Immediate administration during a slow inspiratory vital capacity maneuver gives the highest intrapulmonary deposition (30-40%). Compressed air and ultrasonic nebulizers with a particle distribution pattern of 2-5 micron aerodynamic mass median diameter (AMMD) allow in normal subjects to achieve an intrapulmonary deposition of 30-60% during standardized tidal breathing at rest, the magnitude of the deposition depending mainly on each subject's larynx geometry. The outlet system leads to different deposition patterns in aerosol generators with the same AMMD. Many commercially available aerosol generators do not fulfill the criteria for any intrapulmonary aerosol deposition. For drug administration into the lungs, condensation aerosol generators ('steam boiler nebulizers') are useless as well as compressed-air, ultrasonic and steam driven nebulizers with a particle size of more than 10 micron AMMD.

  20. Preparation, characterization and electrochromic properties of composite thin films incorporation of polyaniline

    NASA Astrophysics Data System (ADS)

    Farasat, Mahshid; Golzan, M. Maqsood; Farhadi, Khalil; Shojaei, S. H. Reza; Gheisvandi, Sorayya

    2016-05-01

    Two different electrochromic composite films consisting of aniline/sodium molybdate (S1) and aniline/ferric nitrate (S2) were obtained by electrochemical polymerization method on indium tin oxide (ITO) coated glass substrates in oxalic acid (H2C2O4ṡ2H2O) aqueous solution. The electrochromic properties of the resulting thin films were investigated by spectroelectrochemical measurement and cyclic voltammetry (CV). Under a square electrical potential, they show capacitive current characteristic and represent electrochromic performance, with maximum optical attenuations (ΔT%) of 30.8% at 355nm and 28.3% at 400nm for aniline/ferric nitrate and aniline/sodium molybdate thin films, respectively. Optical behavior of thin films was examined by UV-Vis spectrophotometry technique. The doped films indicated multiple color changes (yellow; green; and bluish green). The spectra also showed that produced layers have high absorption of UV radiation with respect to pure polyaniline (PANI) films. The optical band gap energy of PANI film decreased by dopant injection. Due to their decent transparency and electrochromic behavior, they are promising materials for electrochromic devices.

  1. Nanosoldering carbon nanotube junctions by local chemical vapor deposition for improved device performance.

    PubMed

    Do, Jae-Won; Estrada, David; Xie, Xu; Chang, Noel N; Mallek, Justin; Girolami, Gregory S; Rogers, John A; Pop, Eric; Lyding, Joseph W

    2013-01-01

    The performance of carbon nanotube network (CNN) devices is usually limited by the high resistance of individual nanotube junctions (NJs). We present a novel method to reduce this resistance through a nanoscale chemical vapor deposition (CVD) process. By passing current through the devices in the presence of a gaseous CVD precursor, localized nanoscale Joule heating induced at the NJs stimulates the selective and self-limiting deposition of metallic nanosolder. The effectiveness of this nanosoldering process depends on the work function of the deposited metal (here Pd or HfB2), and it can improve the on/off current ratio of a CNN device by nearly an order of magnitude. This nanosoldering technique could also be applied to other device types where nanoscale resistance components limit overall device performance. PMID:24215439

  2. Design and characterization of a durable and highly efficient energy-harvesting electrochromic window

    NASA Astrophysics Data System (ADS)

    Amasawa, Eri

    With the growing global energy demands, electrochromic window (ECW) technology has attracted great attention for its ability to reversibly change the transmittance of incoming light through applied moderate potential. While ECW has a great potential to conserve energy from lighting and air conditioning in buildings, ECW still consumes energy; ECW should be self-powered for further energy conservation. In this study, a new design of energy-harvesting electrochromic window (EH-ECW) based on fusion of two technologies, organic electrochromic window and dye-sensitized solar cell (DSSC) is presented. Unlike other self-powered smart windows such as photoelectrochromic device that only contains two states (i.e. closed circuit colored state and open circuit bleaching state), EH-ECW allows active tuning of transmittance through varying applied potential and function as a photovoltaic cell based on DSSC. The resulting device demonstrates fast switching rate of 1 second in both bleaching and coloring process through the use of electrochromic polymer as a counter electrode layer. In order to increase the transmittance of the device, cobalt redox couple and light colored yet efficient organic dye are employed. The organic dye utilized contains polymeric structure, which contributes to high cyclic stability. The device exhibits power conversion efficiency (PCE) of 4.5 % under AM 1.5 irradiation (100 mW/cm2), change in transmittance (Delta T = Tmax - Tmin) of 34 % upon applied potential, and shows only 3 % degradation in PCE after 5000 cycles.

  3. Eliminating Electrochromic Degradation in Amorphous TiO2 through Li-Ion Detrapping.

    PubMed

    Wen, Rui-Tao; Niklasson, Gunnar A; Granqvist, Claes G

    2016-03-01

    The quest for superior and low-cost electrochromic (EC) thin films, for applications in smart windows, remains strong because of their large importance for energy-efficient buildings. Although the development of new EC materials for improved devices is important, diminishing or reversing degradation is another key issue, and electrical rejuvenation of degraded EC materials can offer new opportunities. Here we demonstrate that cathodically coloring EC thin films of TiO2, which normally suffer from ion-trapping-induced degradation of charge capacity and optical modulation upon extensive electrochemical cycling, can recover their initial EC performance by a rejuvenation procedure involving Li(+) ion detrapping. Thus, the initial performance can be regained, and refreshed TiO2 films exhibit the same degradation features as as-deposited films upon prolonged electrochemical cycling. The rejuvenation was carried out by using either galvanostatic or potentiostatic treatments. Our study may open avenues to explore the recovery not only of EC materials and devices based on those but also for other ion-exchange-based devices. PMID:26910644

  4. Co-deposition methods for the fabrication of organic optoelectronic devices

    DOEpatents

    Thompson, Mark E.; Liu, Zhiwei; Wu, Chao

    2016-09-06

    A method for fabricating an OLED by preparing phosphorescent metal complexes in situ is provided. In particular, the method simultaneously synthesizes and deposits copper (I) complexes in an organic light emitting device. Devices comprising such complexes may provide improved photoluminescent and electroluminescent properties.

  5. Deposition of Thin Film Using a Surface Acoustic Wave Device

    NASA Astrophysics Data System (ADS)

    Murochi, Nobuaki; Sugimoto, Mitsunori; Matsui, Yoshikazu; Kondoh, Jun

    2007-07-01

    When a Rayleigh surface acoustic wave (SAW) propagates at a liquid/solid interface, it radiates its energy into the adjacent liquid. If a liquid droplet is loaded on the SAW propagation surface, droplet vibration, streaming, jetting, and atomization are observed. These phenomena are called SAW streaming. In this paper, a novel thin-film deposition method based on the atomization of SAW streaming phenomena is proposed. The liquid with film material is loaded on the SAW propagation surface and the liquid is atomized. The atomization direction depends on the Rayleigh angle, which is determined by the sound velocity in the liquid and the SAW velocity. For easy fabrication of a thin uniform film, the atomization direction is controlled in the perpendicular direction. Using the developed system, the deposition of pigments in ink is carried out. The results observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicate that a pigment layer is formed on a glass plate.

  6. Electrochromic materials, devices and process of making

    DOEpatents

    Richardson, Thomas J.

    2003-11-11

    Thin films of transition metal compositions formed with magnesium that are metals, alloys, hydrides or mixtures of alloys, metals and/or hydrides exhibit reversible color changes on application of electric current or hydrogen. Thin films of these materials are suitable for optical switching elements, thin film displays, sun roofs, rear-view mirrors and architectural glass.

  7. Rapid deposition process for zinc oxide film applications in pyroelectric devices

    NASA Astrophysics Data System (ADS)

    Hsiao, Chun-Ching; Yu, Shih-Yuan

    2012-10-01

    Aerosol deposition (AD) is a rapid process for the deposition of films. Zinc oxide is a low toxicity and environmentally friendly material, and it possesses properties such as semiconductivity, pyroelectricity and piezoelectricity without the poling process. Therefore, AD is used to accelerate the manufacturing process for applications of ZnO films in pyroelectric devices. Increasing the temperature variation rate in pyroelectric films is a useful method for enhancing the responsivity of pyroelectric devices. In the present study, a porous ZnO film possessing the properties of large heat absorption and high temperature variation rate is successfully produced by the AD rapid process and laser annealing for application in pyroelectric devices.

  8. Preventing Technique of Metal Deposition on Optical Devices in Space Diode Laser Welding for Space Applications

    NASA Astrophysics Data System (ADS)

    Suita, Yoshikazu; Tanaka, Kenji; Ohtani, Masato; Shobako, Shinichiro; Terajima, Noboru; Hiraoka, Nobuaki

    In future space developments, the welding in space may be required for the repairs of the ISS and the constructions of lunar base and space structures. The authors have studied the space Gas Hollow Tungsten Arc (GHTA) welding process since 1993. This paper describes the results for space applying the space Diode Laser (DL) welding process which the authors proposed in 2002. It is necessary to prevent the metal deposition on optical devices in order to utilize the space DL welding process in space. The authors studied the preventing technique of metal deposition which covered optical devices with the nozzle and blew the shielding gas out from nozzle outlet. The metal deposition can be reduced by supplying the nozzle with inert gas and blowing the gas out from nozzle outlet. The shielding gas argon perfectly prevents the metal deposition on optical devices when argon pressurizes the nozzle to over 19.9 Pa and spouts out from the nozzle outlet.

  9. Technology Advancements to Lower Costs of Electrochromic Window Glazing

    SciTech Connect

    Mark Burdis; Neil Sbar

    2008-07-13

    An Electrochromic (EC) Window is a solar control device that can electronically regulate the flow of sunlight and heat. In the case of the SageGlass{reg_sign} EC window, this property derives from a proprietary all-ceramic, intrinsically durable thin-film stack applied to an inner surface of a glass double-pane window. As solar irradiation and temperatures change, the window can be set to an appropriate level of tint to optimize the comfort and productivity of the occupants as well as to minimize building energy usage as a result of HVAC and lighting optimization. The primary goal of this project is to replace certain batch processes for EC thin film deposition resulting in a complete in-line vacuum process that will reduce future capital and labor coats, while increasing throughput and yields. This will require key technology developments to replace the offline processes. This project has enabled development of the next generation of electrochromic devices suitable for large-scale production. Specifically, the requirements to produce large area devices cost effectively require processes amenable to mass production, using a variety of different substrate materials, having minimal handling and capable of being run at high yield. The present SageGlass{reg_sign} production process consists of two vacuum steps separated by an atmospheric process. This means that the glass goes through several additional handling steps, including venting and pumping down to go from vacuum to atmosphere and back, which can only serve to introduce additional defects associated with such processes. The aim of this project therefore was to develop a process which would eliminate the need for the atmospheric process. The overall project was divided into several logical tasks which would result in a process ready to be implemented in the present SAGE facility. Tasks 2 and 3 were devoted to development and the optimization of a new thin film material process. These tasks are more complicated

  10. Characterization of bismuth nanospheres deposited by plasma focus device

    SciTech Connect

    Ahmad, M.; Al-Hawat, Sh.; Akel, M.; Mrad, O.

    2015-02-14

    A new method for producing thin layer of bismuth nanospheres based on the use of low energy plasma focus device is demonstrated. Various techniques such as scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been used to characterize the morphology and the composition of the nanospheres. Experimental parameters may be adjusted to favour the formation of bismuth nanospheres instead of microspheres. Therefore, the formation of large surface of homogeneous layer of bismuth nanospheres with sizes of below 100 nm can be obtained. The natural snowball phenomenon is observed to be reproduced in nanoscale where spheres roll over the small nanospheres and grow up to bigger sizes that can reach micro dimensions. The comet-like structure, a reverse phenomenon to snowball is also observed.

  11. Integrated smart electrochromic windows for energy saving and storage applications.

    PubMed

    Xie, Zhong; Jin, Xiujuan; Chen, Gui; Xu, Jing; Chen, Di; Shen, Guozhen

    2014-01-18

    A self-powered electrochromic smart window with tunable transmittance driven by dye-sensitized solar cells has been designed, which also acts as a photocharged electrochromic supercapacitor with high areal capacitance and reversible color changes. PMID:24281715

  12. Integrated smart electrochromic windows for energy saving and storage applications.

    PubMed

    Xie, Zhong; Jin, Xiujuan; Chen, Gui; Xu, Jing; Chen, Di; Shen, Guozhen

    2014-01-18

    A self-powered electrochromic smart window with tunable transmittance driven by dye-sensitized solar cells has been designed, which also acts as a photocharged electrochromic supercapacitor with high areal capacitance and reversible color changes.

  13. A fast electrochromic polymer based on TEMPO substituted polytriphenylamine

    NASA Astrophysics Data System (ADS)

    Ji, Lvlv; Dai, Yuyu; Yan, Shuanma; Lv, Xiaojing; Su, Chang; Xu, Lihuan; Lv, Yaokang; Ouyang, Mi; Chen, Zuofeng; Zhang, Cheng

    2016-07-01

    A novel strategy to obtain rapid electrochromic switching response by introducing 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) moiety into polytriphenylamine backbone has been developed. The electrochromic properties of the integrated polymer film are investigated and a possible mechanism is proposed with TEMPO as a counterion-reservoir group to rapidly balance the charges during electrochromic switching, which leads to significantly improved electrochromism performance.

  14. A fast electrochromic polymer based on TEMPO substituted polytriphenylamine.

    PubMed

    Ji, Lvlv; Dai, Yuyu; Yan, Shuanma; Lv, Xiaojing; Su, Chang; Xu, Lihuan; Lv, Yaokang; Ouyang, Mi; Chen, Zuofeng; Zhang, Cheng

    2016-07-22

    A novel strategy to obtain rapid electrochromic switching response by introducing 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) moiety into polytriphenylamine backbone has been developed. The electrochromic properties of the integrated polymer film are investigated and a possible mechanism is proposed with TEMPO as a counterion-reservoir group to rapidly balance the charges during electrochromic switching, which leads to significantly improved electrochromism performance.

  15. A fast electrochromic polymer based on TEMPO substituted polytriphenylamine.

    PubMed

    Ji, Lvlv; Dai, Yuyu; Yan, Shuanma; Lv, Xiaojing; Su, Chang; Xu, Lihuan; Lv, Yaokang; Ouyang, Mi; Chen, Zuofeng; Zhang, Cheng

    2016-01-01

    A novel strategy to obtain rapid electrochromic switching response by introducing 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) moiety into polytriphenylamine backbone has been developed. The electrochromic properties of the integrated polymer film are investigated and a possible mechanism is proposed with TEMPO as a counterion-reservoir group to rapidly balance the charges during electrochromic switching, which leads to significantly improved electrochromism performance. PMID:27444398

  16. A fast electrochromic polymer based on TEMPO substituted polytriphenylamine

    PubMed Central

    Ji, Lvlv; Dai, Yuyu; Yan, Shuanma; Lv, Xiaojing; Su, Chang; Xu, Lihuan; Lv, Yaokang; Ouyang, Mi; Chen, Zuofeng; Zhang, Cheng

    2016-01-01

    A novel strategy to obtain rapid electrochromic switching response by introducing 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) moiety into polytriphenylamine backbone has been developed. The electrochromic properties of the integrated polymer film are investigated and a possible mechanism is proposed with TEMPO as a counterion-reservoir group to rapidly balance the charges during electrochromic switching, which leads to significantly improved electrochromism performance. PMID:27444398

  17. A vertically integrated solar-powered electrochromic window for energy efficient buildings.

    PubMed

    Dyer, Aubrey L; Bulloch, Rayford H; Zhou, Yinhua; Kippelen, Bernard; Reynolds, John R; Zhang, Fengling

    2014-07-23

    A solution-processed self-powered polymer electrochromic/photovoltaic (EC/PV) device is realized by vertically integrating two transparent PV cells with an ECD. The EC/PV cell is a net energy positive dual functional device, which can be reversibly switched between transparent and colored states by PV cells for regulating incoming sunlight through windows. The two PV cells can individually, or in pairs, generate electricity. PMID:24863393

  18. Optimization of a plasma focus device as an electron beam source for thin film deposition

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Lin, J.; Patran, A.; Wong, D.; Hassan, S. M.; Mahmood, S.; White, T.; Tan, T. L.; Springham, S. V.; Lee, S.; Lee, P.; Rawat, R. S.

    2007-05-01

    Electron beam emission characteristics from neon, argon, hydrogen and helium in an NX2 dense plasma focus (DPF) device were investigated in order to optimize the plasma focus device for deposition of thin films using energetic electron beams. A Rogowski coil and CCD based magnetic spectrometer were used to obtain temporal characteristics, total electron charge and energy distributions of electron emission from the NX2 DPF device. It is found that hydrogen should be the first choice for thin film deposition as it produces the highest electron beam charge and higher energy (from 50 to 200 keV) electrons. Neon is the next best choice as it gives the next highest electron beam charge with mid-energy (from 30 to 70 keV) electrons. The operation of NX2 with helium at voltages above 12 kV produces a mid-energy (from 30 to 70 keV) electron beam with low-electron beam charge, however, argon is not a good electron beam source for our NX2 DPF device. Preliminary results of the first ever thin film deposition using plasma focus assisted pulsed electron deposition using a hydrogen operated NX2 plasma focus device are presented.

  19. RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

    SciTech Connect

    Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan; Lantz, Kevin R.

    2012-07-30

    Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host matrix. A unique emulsion-based RIR-MAPLE approach has been developed that reduces substrate exposure to solvents and provides controlled and repeatable organic thin film deposition. In order to establish emulsion-based RIR-MAPLE as a preferred deposition technique for conjugated polymer or hybrid nanocomposite optoelectronic devices, studies have been conducted to demonstrate the value added by the approach in comparison to traditional solution-based deposition techniques, and this work will be reviewed. The control of hybrid nanocomposite thin film deposition, and the photoconductivity in such materials deposited using emulsion-based RIR-MAPLE, will also be reviewed. The overall result of these studies is the demonstration of emulsion-based RIR-MAPLE as a viable option for the fabrication of conjugated polymer and hybrid nanocomposite optoelectronic devices that could yield improved device performance.

  20. Characterization of CZTSSe photovoltaic device with an atomic layer-deposited passivation layer

    SciTech Connect

    Wu, Wei Cao, Yanyan; Caspar, Jonathan V.; Guo, Qijie; Johnson, Lynda K.; Mclean, Robert S.; Malajovich, Irina; Choudhury, Kaushik Roy

    2014-07-28

    We describe a CZTSSe (Cu{sub 2}ZnSn(S{sub 1−x},Se{sub x}){sub 4}) photovoltaic (PV) device with an ALD (atomic layer deposition) coated buffer dielectric layer for CZTSSe surface passivation. An ALD buffer layer, such as TiO{sub 2}, can be applied in order to reduce the interface recombination and improve the device's open-circuit voltage. Detailed characterization data including current-voltage, admittance spectroscopy, and capacitance profiling are presented in order to compare the performance of PV devices with and without the ALD layer.

  1. Hydrothermally processed TiO2 nanowire electrodes with antireflective and electrochromic properties.

    PubMed

    Chen, Jing-Zhi; Ko, Wen-Yin; Yen, Yin-Cheng; Chen, Po-Hung; Lin, Kuan-Jiuh

    2012-08-28

    Dual functionalities of antireflective and electrochromic properties-based anatase TiO(2) nanowire devices with a high-porosity cross-linked geometry directly grown onto transparent conductive glass was achieved for the first time through a simple one-step hydrothermal process under mild alkali conditions. Devices fashioned from these TiO(2) nanowires were found to display enhanced optical transparency in the visible range, better color contrast, and faster color-switching time in comparison to devices made from nanoparticles. These improvements can be attributed to the low refractive index and high porosity of the TiO(2) nanowires and their larger accessible surface area for Li(+) intercalation and deintercalation, leading to enhanced capabilities for transparent electrochromic smart windows. PMID:22757633

  2. Stable and efficient electrophosphorescent organic light-emitting devices grown by organic vapor phase deposition

    NASA Astrophysics Data System (ADS)

    Zhou, Theodore X.; Ngo, Tan; Brown, Julie J.; Shtein, Max; Forrest, Stephen R.

    2005-01-01

    An electrophosphorescent organic light-emitting device (PHOLED™) employing fac-tris(2-phenylpyridine)iridium [Ir(ppy)3] as the green emitting phosphor has been fabricated using a pilot-production organic vapor phase deposition (OVPD™) system. Highly controlled mass transport of the organic vapor to the substrate results in deposition rates of over 10Å/s and spatial uniformity better than ±2% across a 150mm×150mm substrate with less than ±2% run-to-run variations. The device current-voltage, luminous efficiency, and operational lifetime performances are compared to those of a similar device grown by conventional vacuum thermal evaporation (VTE). The green OVPD-grown PHOLED exhibits a maximum external quantum efficiency of (7.0±0.1)% at a luminance of 1000cd/m2, comparable to the VTE device performance. The operational lifetime of the OVPD-grown devices was found to be comparable to or even somewhat longer than the lifetime achieved by VTE. Furthermore, PHOLEDs with emissive layers deposited at 4.8 and 10.8Å/s are compared, and demonstrate equivalent performance.

  3. Amorphous tungstate precursor route to nanostructured tungsten oxide film with electrochromic property.

    PubMed

    Jeon, Ie-Rang; Kang, Joo-Hee; Paek, Seung-Min; Hwang, Seong-Ju; Choy, Jin-Ho

    2011-07-01

    Electrochromic tungsten oxide (WO3) films on ITO glass were fabricated by spin-coating with a tungsten peroxy acid solution, which was prepared by adding an equivolume mixture of hydrogen peroxide and glacial acetic acid to tungsten metal powder. The structural evolution of the tungstate precursor upon heat treatment was studied by X-ray diffraction (XRD) and X-ray absorption near edge structure (XANES) analyses, which indicated that the as-synthesized tungstate transformed into nanocrystalline WO3 upon heating. It is, therefore, quite clear that as-synthesized tungstate can be a good precursor for electrochromic WO3 films. A series of WO3 thin films were prepared on ITO glass by spin-coating with different concentrations of tungsten peroxy acid solution and then post-annealing at various temperatures. Depending on the concentration of the tungstate coating solution (200-500 mg mL(-1)) and the annealing temperature (100-300 degrees C), the thickness and WO3 content as well as the electrochromic properties of WO3 films can be controlled. As a result, the optimum fabrication conditions were determined to be a tungstate solution concentration of 300-400 mg mL(-1) and a post-annealing temperature of 200 degrees C. Finally, an inorganic-inorganic hybrid electrochromic device (ECD) composed of optimized WO3 and Prussian Blue (PB) with desirable coloration efficiency was successfully developed. PMID:22121748

  4. The donor-acceptor approach allows a black-to-transmissive switching polymeric electrochrome

    NASA Astrophysics Data System (ADS)

    Beaujuge, P. M.; Ellinger, S.; Reynolds, J. R.

    2008-10-01

    In the context of the fast-growing demand for innovative high-performance display technologies, the perspective of manufacturing low-cost functional materials that can be easily processed over large areas or finely printed into individual pixels, while being mechanically deformable, has motivated the development of novel electronically active organic components fulfilling the requirements for flexible displays and portable applications. Among all technologies relying on a low-power stimulated optical change, non-emissive organic electrochromic devices (ECDs) offer the advantage of being operational under a wide range of viewing angles and lighting conditions spanning direct sunlight as desired for various applications including signage, information tags and electronic paper. Combining mechanical flexibility, high contrast ratios and fast response times, along with colour tunability through structural control, polymeric electrochromes constitute the most attractive organic electronics for tomorrow's reflective/transmissive ECDs and displays. Although red, blue and most recently green electrochromic polymers (ECPs) required for additive primary colour space were investigated, attempts to make saturated black ECPs have not been reported, probably owing to the complexity of designing materials absorbing effectively over the whole visible spectrum. Here, we report on the use of the donor-acceptor approach to make the first neutral-state black polymeric electrochrome. Processable black-to-transmissive ECPs promise to affect the development of both reflective and transmissive ECDs by providing lower fabrication and processing costs through printing, spraying and coating methods, along with good scalability when compared with their traditional inorganic counterparts.

  5. Heliocentric trajectory analysis of Sun-pointing smart dust with electrochromic control

    NASA Astrophysics Data System (ADS)

    Mengali, Giovanni; Quarta, Alessandro A.

    2016-02-01

    A smart dust is a micro spacecraft, with a characteristic side length on the order of a few millimeters, whose surface is coated with electrochromic material. Its orbital dynamics is controlled by exploiting the differential force due to the solar radiation pressure, which is obtained by modulating the reflectivity coefficient of the electrochromic material within a range of admissible values. A significant thrust level can be reached due to the high values of area-to-mass ratio of such a spacecraft configuration. Assuming that the smart dust is designed to achieve a passive Sun-pointing attitude, the propulsive acceleration due to the solar radiation pressure lies along the Sun-spacecraft direction. The aim of this paper is to study the smart dust heliocentric dynamics in order to find a closed form, analytical solution of its trajectory when the reflectivity coefficient of the electrochromic material can assume two values only. The problem is addressed by introducing a suitable transformation that regularizes the spacecraft motion and translates the smart-dust dynamics into that of a linear harmonic oscillator with unitary frequency, whose forcing input is a boxcar function. The solution is found using the Laplace transform method, and afterwards the problem is generalized by accounting for the degradation of the electrochromic material due to its exposition to the solar radiation. Three spacecraft configurations, corresponding to low, medium and high performance smart dusts, are finally used to quantify the potentialities of these advanced devices in an interplanetary mission scenario.

  6. Plasma damage monitoring for PECVD deposition: a contact potential difference study and device yield analysis

    NASA Astrophysics Data System (ADS)

    Xu, Zhiwei; Bencher, Christopher; Le, Maggie; Ngai, Chris

    1998-08-01

    A study was conducted to monitor plasma induced charging during a plasma enhanced chemical vapor deposition (PECVD) process. A contact potential difference (CPD) technique was used for the charge measurement on non-device blank wafers. In two TEOS based PECVD SiO2 deposition processes, one phosphorous doped and one undoped (USG), the plasma induced charging behavior was monitored while deposition conditions were varied. It was found that the process deposition pressure had a large effect on the plasma induced charging behavior. For both the PSG and the USG deposition processes, higher pressure process regimes offered significantly improved plasma charging performance than the conventional low pressure regimes. The CPD was reduced from -13.5V to 1.5V for the PSG process, and the CPD uniformity was reduced from 8.17V to 2.39V for the USG process. The improved deposition process conditions were tested on thin gate antenna test structures and correlated to significant improved device yield. Additionally, a plasma assisted de- chucking process was analyzed using the CPD technique and found to be an important source of plasma induced charging. When test were performed on thin gate antenna test structures the CPD again correlated well yield trends. In summary, the study demonstrated that CPD is a powerful, inexpensive, and rapid technique suitable for developing processes with improved gate oxide yield and for in-line monitoring of chamber performance.

  7. Deposition of device quality, low hydrogen content, hydrogenated amorphous silicon at high deposition rates

    DOEpatents

    Mahan, Archie Harvin; Molenbroek, Edith C.; Gallagher, Alan C.; Nelson, Brent P.; Iwaniczko, Eugene; Xu, Yueqin

    2002-01-01

    A method of fabricating device quality, thin-film a-Si:H for use as semiconductor material in photovoltaic and other devices, comprising in any order; positioning a substrate in a vacuum chamber adjacent a plurality of heatable filaments with a spacing distance L between the substrate and the filaments; heating the filaments to a temperature that is high enough to obtain complete decomposition of silicohydride molecules that impinge said filaments into Si and H atomic species; providing a flow of silicohydride gas, or a mixture of silicohydride gas containing Si and H, in said vacuum chamber while maintaining a pressure P of said gas in said chamber, which, in combination with said spacing distance L, provides a P.times.L product in a range of 10-300 mT-cm to ensure that most of the Si atomic species react with silicohydride molecules in the gas before reaching the substrate, to thereby grow a a-Si:H film at a rate of at least 50 .ANG./sec.; and maintaining the substrate at a temperature that balances out-diffusion of H from the growing a-Si:H film with time needed for radical species containing Si and H to migrate to preferred bonding sites.

  8. Variable Emittance Electrochromics Using Ionic Electrolytes and Low Solar Absorptance Coatings

    NASA Technical Reports Server (NTRS)

    Chandrasekhar, Prasanna

    2011-01-01

    One of the last remaining technical hurdles with variable emittance devices or skins based on conducting polymer electrochromics is the high solar absorptance of their top surfaces. This high solar absorptance causes overheating of the skin when facing the Sun in space. Existing technologies such as mechanical louvers or loop heat pipes are virtually inapplicable to micro (< 20 kg) and nano (< 5 kg) spacecraft. Novel coatings lower the solar absorption to Alpha(s) of between 0.30 and 0.46. Coupled with the emittance properties of the variable emittance skins, this lowers the surface temperature of the skins facing the Sun to between 30 and 60 C, which is much lower than previous results of 100 C, and is well within acceptable satellite operations ranges. The performance of this technology is better than that of current new technologies such as microelectromechanical systems (MEMS), electrostatics, and electrophoretics, especially in applications involving micro and nano spacecraft. The coatings are deposited inside a high vacuum, layering multiple coatings onto the top surfaces of variable emittance skins. They are completely transparent in the entire relevant infrared region (about 2 to 45 microns), but highly reflective in the visible-NIR (near infrared) region of relevance to solar absorptance.

  9. Theoretical investigation of acoustic wave devices based on different piezoelectric films deposited on silicon carbide

    NASA Astrophysics Data System (ADS)

    Fan, Li; Zhang, Shu-yi; Ge, Huan; Zhang, Hui

    2013-07-01

    Performances of acoustic wave (AW) devices based on silicon carbide (SiC) substrates are theoretically studied, in which two types of piezoelectric films of ZnO and AlN deposited on 4H-SiC and 3C-SiC substrates are adopted. The phase velocities (PV), electromechanical coupling coefficients (ECC), and temperature coefficients of frequency (TCF) for three AW modes (Rayleigh wave, A0 and S0 modes of Lamb wave) often used in AW devices are calculated based on four types of configurations of interdigital transducers (IDTs). It is found that that the ZnO piezoelectric film is proper for the AW device operating in the low-frequency range because a high ECC can be realized using a thin ZnO film. The AlN piezoelectric film is proper for the device operating in the high-frequency range in virtue of the high PV of AlN, which can increase the finger width of the IDT. Generally, in the low-frequency Lamb wave devices using ZnO piezoelectric films with small normalized thicknesses of films to wavelengths hf/λ, thin SiC substrates can increase ECCs but induce high TCFs simultaneously. In the high-frequency device with a large hf/λ, the S0 mode of Lamb wave based on the AlN piezoelectric film deposited on a thick SiC substrate exhibits high performances by simultaneously considering the PV, ECC, and TCF.

  10. Layer-by-layer Collagen Deposition in Microfluidic Devices for Microtissue Stabilization

    PubMed Central

    McCarty, William J.; Prodanov, Ljupcho; Bale, Shyam Sundhar; Bhushan, Abhinav; Jindal, Rohit; Yarmush, Martin L.; Usta, O. Berk

    2016-01-01

    Although microfluidics provides exquisite control of the cellular microenvironment, culturing cells within microfluidic devices can be challenging. 3D culture of cells in collagen type I gels helps to stabilize cell morphology and function, which is necessary for creating microfluidic tissue models in microdevices. Translating traditional 3D culture techniques for tissue culture plates to microfluidic devices is often difficult because of the limited channel dimensions. In this method, we describe a technique for modifying native type I collagen to generate polycationic and polyanionic collagen solutions that can be used with layer-by-layer deposition to create ultrathin collagen assemblies on top of cells cultured in microfluidic devices. These thin collagen layers stabilize cell morphology and function, as shown using primary hepatocytes as an example cell, allowing for the long term culture of microtissues in microfluidic devices. PMID:26485274

  11. Method of forming ultra thin film devices by vacuum arc vapor deposition

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F. (Inventor)

    2005-01-01

    A method for providing an ultra thin electrical circuit integral with a portion of a surface of an object, including using a focal Vacuum Arc Vapor Deposition device having a chamber, a nozzle and a nozzle seal, depressing the nozzle seal against the portion of the object surface to create an airtight compartment in the chamber and depositing one or more ultra thin film layer(s) only on the portion of the surface of the object, the layers being of distinct patterns such that they form the circuit.

  12. Computer Modeling of Flow, Thermal Condition and Ash Deposition in a Hot-Gas Filtration Device

    SciTech Connect

    Ahmadi, G.; Mazaheri, A.; Liu, C.; Gamwo, I.K.

    2002-09-19

    The objective of the present study is to develop a computational model for simulating the gas flow, thermal condition and ash transport and deposition pattern in the hot-gas filtration systems. The computational model is to provide a virtual tool for design and operation modifications. Particular attention is given to the Particle Control Device (PCD) at the Power Systems Development Facility (PSDF) in Wilsonville, Alabama. For evaluation of gas velocity and temperature field in the vessel, the FLUENT commercial CFD computer code is used. Ash particle transport and deposition pattern was analyzed with the Lagrangian particle tracking approach.

  13. Semiconductor/solid electrolyte junctions for optical information storage. Solid-state electrochromic cell using lutecium diphthalocyanine

    NASA Astrophysics Data System (ADS)

    Sammells, A. F.; Pujare, N. U.

    1986-01-01

    The overall program goal is to perform a basic investigation of photoelectrochemical and electrochemical effects by electrochromic materials in solid polymer electrolyte (SPE) containing solid-state cells. Initial investigations have been directed towards reversible electrochromic behavior at the interface between lutecium diphthalocyanine deposited onto electronically conducting glass, and the homopolymer poly-2-acrylamido -2-methylpropane sulfonic acid (poly(Amps)). We wish to report here some recent work on solid-state electrochromic cells in which ionic mediation to thin-film deposits of lutecium diphthalocyanine is via the homopolymer poly-2-acrylamido-2-methyl propane sulfonic acid (poly-Amps). Separation between the working (LuH(Pc)2 deposited onto SnO2 conducting glass) and counter (CeCl3 in poly (Amps)) electrodes in these solid-state cells was realized by the use of the insoluble copolymer perfluorosulfonic acid (Nafion). Solid-state electrochromic cells were prepared using the supporting electrolytes (SEs) 0.1M Na2SO4 and 0.1M KCl. Upon subjecting the cell to anodic and cathodic voltage scans, up to four distinct color changes were observed varying from red (at anodic potentials) to violet (at cathodic potentials). Formation of the violet lutecium diphthalocyanine reduction product was not found contingent upon the absence of alkali cations as reported by others.

  14. In vitro monodisperse aerosol deposition in a mouth and throat with six different inhalation devices.

    PubMed

    DeHaan, W H; Finlay, W H

    2001-01-01

    Experiments were performed to determine the effect of different pharmaceutical aerosol inhalation devices on the deposition of monodisperse aerosols in an idealized mouth and throat geometry. The devices included two dry powder inhalers (Diskus and Turbuhaler), two nebulizers (Pari LC STAR and Hudson T-Updraft), and a metered dose inhaler with attached holding chamber (Aerochamber), in addition to a straight tube (1.7 cm inner diameter). Aerosol particles (DL-alpha tocopheryl acetate) of diameters of 2.5, 5, and 7 microm generated by a vibrating orifice generator were inhaled at steady air flow rates of Q = 5-90 L/min through the devices and into the mouth-throat. Deposition in the mouth-throat and after-filter were determined by ultraviolet (UV) spectrophotometric assay. The amount of deposition in the mouth and throat region was found to depend on the type of device that the aerosol entered through. Deposition in the extrathoracic region with the two types of jet nebulizers did not differ significantly (p > 0.1) from that of a straight tube or each other over their entire tested range of 590 > or = pd2Q > or = 11,375, where p is particle density (in g/cm3), d is particle diameter (in microm), and Q is flow rate (in cm3/s). The metered dose inhaler with attached holding chamber was found to differ from the straight tube only at two intermediate values of pd2Q = 5,145 and 16,033. The deposition occurring for the dry powder inhalers was found to be significantly greater than for the straight tube for all values of pd2Q > or = 10,954 for the Diskus and pd2Q > or = 9,435 for the Turbuhaler. Deposition with the dry powder inhalers was found to be up to 14 times greater than that with the straight tube. Thus, the inhaler geometry that the aerosol passes through prior to entering the mouth and throat region can greatly affect the deposition in the mouth-throat.

  15. Electrophoretic Deposition as a Cost-effective Method for Fabrication of Efficient Thermoelectric Devices

    NASA Astrophysics Data System (ADS)

    Amrollahi, P.; Razavi, M.; Yazdimamaghani, M.; Vaidyanathan, R.; Tayebi, L.; Vashaee, D.; Nserg Team

    2014-03-01

    With the new advances in thermoelectric (TE) technology, there is an increasing need to develop thick film structures that would allow chip scale fabrication of TE devices. TE modules made from thin film materials often suffer from low efficiency due to the sensitivity to the ohmic contact resistance and low fabrication yield due to the sensitivity to the height variation of the TE leg. In order to maintain a high efficiency at the device level, the ohmic contact resistance must be very smaller than the resistance of the TE material, which necessitates a film thickness of at least several tens of microns. However, growth of such thick films with vacuum deposition systems is too expensive for commercial viability. In this investigation, a method based on electrophoretic deposition (EPD) is presented for the development of thick TE films. The method allows a wide range of thicknesses up to several hundred microns in a rather simple and inexpensive approach. TE films of doped silicon germanium were deposited via EPD and their TE properties were evaluated. The films showed promising properties comparable to single crystalline silicon germanium alloy. The results proved a new method for fabrication of chip scale TE devices.

  16. Visualization of energy: light dose indicator based on electrochromic gyroid nano-materials

    NASA Astrophysics Data System (ADS)

    Wei, Di; Scherer, Maik R. J.; Astley, Michael; Steiner, Ullrich

    2015-06-01

    The typical applications of electrochromic devices do not make use of the charge-dependent, gradual optical response due to their slow voltage-sensitive coloration. However, in this paper we present a design for a reusable, self-powered light dose indicator consisting of a solar cell and a gyroid-structured nickel oxide (NiO) electrochromic display that measures the cumulative charge per se, making use of the efficient voltage-sensitive coloration of gyroid materials. To circumvent the stability issues associated with the standard aqueous electrolyte that is typically accompanied by water splitting and gas evolution, we investigate a novel nano-gyroid NiO electrochromic device based on organic solvents of 1,1,1,3,3,3-hexafluoropropan-2-ol, and room temperature ionic liquid (RTIL) triethylsulfonium bis(trifluoromethylsulfonyl) imide ([SET3][TFSI]) containing lithium bis(trifluoromethylsulfonyl) imide. We show that an effective light dose indicator can be enabled by nano-gyroid NiO with RTIL; this proves to be a reliable device since it does not involve solvent degradation or gas generation.

  17. The inhalation device influences lung deposition and bronchodilating effect of terbutaline.

    PubMed

    Borgström, L; Derom, E; Ståhl, E; Wåhlin-Boll, E; Pauwels, R

    1996-05-01

    The development of new inhalation devices for asthma drugs raises the issue of the relationship between pulmonary deposition and therapeutic effect of inhaled drugs in patients with obstructive lung diseases. We thus conducted a randomized, double-blind and double-dummy, four-period crossover study in 13 patients with moderate asthma (mean age 36 yr; FEV1 59% of predicted), who inhaled 0.25 and 0.5 mg terbutaline sulphate on separate occasions either via a pressurized metered dose inhaler (pMDI) or Turbuhaler (TBH). Pulmonary deposition was 8.1 +/- 2.7% and 8.3 +/- 2.3%, respectively, of the nominal dose for pMDI and 19.0 +/- 7.3%, and 22.0 +/- 8.1% for TBH. The FEV1 increase after 0.25 mg terbutaline sulphate via TBH was significantly greater than after 0.25 mg via pMDI. No significant differences in FEV1 increase were observed between 0.25 mg via TBH, 0.5 mg via pMDI, or 0.5 mg via TBH. Other lung function variables showed similar dose- and device-related changes. We concluded that: (1) the dose of terbutaline sulphate deposited in the lungs is dependent on which inhalation system is used; (2) TBH delivers about twice the amount of drug to the lungs as the pMDI; and (3) the observed difference in deposition is reflected in the bronchodilating effect. PMID:8630614

  18. Single-electron devices fabricated using double-angle deposition and plasma oxidation

    NASA Astrophysics Data System (ADS)

    Hong, Y.; Barcikowski, Z. S.; Ramanayaka, A. N.; Stewart, M. D., Jr.; Zimmerman, N. M.; Pomeroy, J. M.; Quantum Processes; Metrology Group Team

    We report on development of plasma oxidized, single-electron transistors (SETs) where we seek low-capacitance and small-area Al/AlOx/Al tunnel junctions with small charge offset drift. Performance of metal-based SET quantum devices and superconducting devices has suffered from long-term charge offset drift, high defect densities and charge noise. We use plasma oxidation to lower defect densities of the oxide layer, and adjustable deposition angles to control the overlapping areas for Al/AlOx/Al tunnel junctions. Current-voltage and charge offset drift measurements are planned for cryogenic temperatures. Other electrical properties will be measured at room temperature. We hope to see Coulomb blockade oscillations on these devices and better charge offset stability than typical Al/AlOx/Al SETs.

  19. Deposition of device quality amorphous silicon and solar cell from argon dilution of silane

    NASA Astrophysics Data System (ADS)

    Layek, Animesh; Middya, Somnath; Ray, Partha Pratim

    2012-11-01

    In our present study hydrogenated amorphous silicon (a-Si:H) thin films and solar cells have been prepared in a conventional single chamber rf-PECVD unit from silane-argon mixture by varying radio frequency (rf) power densities from 6 mW/cm2 to 50 mW/cm2. By optimizing the properties of the intrinsic material we have chosen a material which is deposited at 6 mW/cm2 rf power density, 0.2 Torr pressure, 175 oC substrate temperature and by 97% argon dilution. For this material minority carriers (holes) diffusion length (Ld) measured in the as deposited state is 180 nm and it degrades by 15% after light soaking. This high Ld value indicates that the material is of device quality. We have fabricated a single junction solar cell having the structure p-a-SiC:H/i-a-Si:H/n-a-Si:H without optimizing the doped layers. This set exhibits a mean open circuit voltage of 0.8 V and conversion efficiency of 7.7%. After light soaking conversion efficiency decreases by 15% which demonstrates that it is possible to deposit device grade material and solar cells from silane-argon mixture.

  20. The solution growth route and characterization of electrochromic tungsten oxide thin films

    SciTech Connect

    Todorovski, Toni; Najdoski, Metodija

    2007-12-04

    Electrochromic tungsten oxide thin films were prepared by using an aqueous solution of Na{sub 2}WO{sub 4}.2H{sub 2}O and dimethyl sulfate. Various techniques were used for the characterization of the films such as X-ray diffraction, cyclic voltammetry, SEM analysis and VIS-spectroscopy. The thin film durability was tested in an aqueous solution of LiClO{sub 4} (0.1 mol/dm{sup 3}) for about 7000 cycles followed by cyclic voltammetry. No significant changes in the cyclic voltammograms were found, thus proving the high durability of the films. The optical transmittance spectra of coloured and bleached states showed significant change in the transmittance, which makes these films favorable for electrochromic devices.

  1. Damage to III-V Devices During Electron Cyclotron Resonance Chemical Vapor Deposition

    SciTech Connect

    Abernathy, C.R.; Hahn, Y.B.; Hays, D.C.; Johnson, D.; Lee, J.W.; MacKenzie, K.; Pearton, S.J.; Ren, F.; Shul, R.J.

    1998-10-14

    GaAs-based metal semiconductor field effect transistors (MESFETS), heterojunction bipolar transistors (HBTs) and high electron mobility transistors (HEMTs) have been exposed to ECR SiJ&/NH3 discharges for deposition of SiNX passivating layers. The effect of source power, rf chuck power, pressure and plasma composition have been investigated. Effects due to both ion damage and hydrogenation of dopants are observed. For both HEMTs and MESFETS there are no conditions where substantial increases in channel sheet resistivity are not observed, due primarily to (Si-H)O complex formation. In HBTs the carbon-doped base layer is the most susceptible layer to hydrogenation. Ion damage in all three devices is minimized at low rf chuck power, moderate ECR source power and high deposition rates.

  2. NREL Electrochromic Window Research Wins Award

    ScienceCinema

    None

    2016-07-12

    Winners of the CO-LABS Governor's Award for High-Impact Research in Energy Efficiency, Dr. Satyen Deb at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) discovered that a small electrical charge can change the opacity of tungsten oxide from clear to tinted. He, Dr. Dane Gillaspie, and their fellow scientists at NREL then applied this knowledge to develop and transfer the technologies required to construct an electrochromic window, which can switch between clear and heavily tinted states. Electrochromic windows allow natural light in while adding tint to reduce summer heat and glare, and going clear to allow sunlight through in the winter. Broad adaptation of these windows could reduce US total energy use by four percent and reduce building cooling loads by 20%, much of this during expensive peak hours. Windows based on these discoveries are now being installed worldwide.

  3. NREL Electrochromic Window Research Wins Award

    SciTech Connect

    2011-01-01

    Winners of the CO-LABS Governor's Award for High-Impact Research in Energy Efficiency, Dr. Satyen Deb at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) discovered that a small electrical charge can change the opacity of tungsten oxide from clear to tinted. He, Dr. Dane Gillaspie, and their fellow scientists at NREL then applied this knowledge to develop and transfer the technologies required to construct an electrochromic window, which can switch between clear and heavily tinted states. Electrochromic windows allow natural light in while adding tint to reduce summer heat and glare, and going clear to allow sunlight through in the winter. Broad adaptation of these windows could reduce US total energy use by four percent and reduce building cooling loads by 20%, much of this during expensive peak hours. Windows based on these discoveries are now being installed worldwide.

  4. Structural and mechanical properties of Al-C-N films deposited at room temperature by plasma focus device

    NASA Astrophysics Data System (ADS)

    Z, A. Umar; R, Ahmad; R, S. Rawat; M, A. Baig; J, Siddiqui; T, Hussain

    2016-07-01

    The Al-C-N films are deposited on Si substrates by using a dense plasma focus (DPF) device with aluminum fitted central electrode (anode) and by operating the device with CH4/N2 gas admixture ratio of 1:1. XRD results verify the crystalline AlN (111) and Al3CON (110) phase formation of the films deposited using multiple shots. The elemental compositions as well as chemical states of the deposited Al-C-N films are studied using XPS analysis, which affirm Al-N, C-C, and C-N bonding. The FESEM analysis reveals that the deposited films are composed of nanoparticles and nanoparticle agglomerates. The size of the agglomerates increases at a higher number of focus deposition shots for multiple shot depositions. Nanoindentation results reveal the variation in mechanical properties (nanohardness and elastic modulus) of Al-C-N films deposited with multiple shots. The highest values of nanohardness and elastic modulus are found to be about 11 and 185 GPa, respectively, for the film deposited with 30 focus deposition shots. The mechanical properties of the films deposited using multiple shots are related to the Al content and C-N bonding.

  5. Nanomaterials for LightManagement in Electro-Optical Devices

    SciTech Connect

    Truong, Vo-Van; Singh, Jai; Tanemura, Sakae; Hu, Michael Z.

    2012-01-01

    sensing applications. In parallel to the experimental development of nanomaterials for light management in devices, theoretical modeling and analysis have also accomplished much progress, and different methods for simulating the optical properties of nanoparticles and structures have been proposed. This special issue of the Journal of Nanomaterials is thus dedicated to articles dealing with nanostructured materials that can be used for light management purpose in different applications. Silicon-rich oxide (SRO) is a dielectric material that contains Si nanoparticles and exhibits interesting physical characteristics for applications in optoelectronic devices. The work by Aceves-Mijares et al. examine, in detail the electro-, cathode- and photoluminescence properties of SRO and discuss the origin of light emission in this type of materials. SRO films, of high and medium silicon excess density, obtained by low-pressure chemical vapor deposition and annealed at 1,100 C have been studied. Results obtained by the authors have led to conclude that SRO emission properties are due to oxidation state nanoagglomerates rather than to nanocrystals, and the emission mechanism is similar to that in the donor-acceptor decay in semiconductors with a specific wide emission spectrum. Two papers are devoted to nanostructured electrochromic thin films, a category of materials most suitable for controlling light transmission or absorption in electrooptical devices, including smart window coatings. Dinh et al. have shown that by mixing nanostructured Ti and W oxides films, one can obtain devices with considerable enhancement of electrochromic efficiency and electrochemical stability as compared to the conventional nonnanostructured films. As large-area mixed Ti and W oxides can be prepared by the simple doctor blade technique followed by an electrochemical process, this type of nanostructured electrochromic films can be considered a good candidate for smart window applications. Djaoued et al

  6. Electrochemical Deposition of Nanostructured Conducting Polymer Coatings on Neural Prosthetic Devices

    NASA Astrophysics Data System (ADS)

    Yang, Junyan; Martin, David

    2003-03-01

    Micromachined neural prosthetic devices facilitate the functional stimulation of and recording from the central nervous system (CNS). These devices have been fabricated to consist of silicon shanks that have gold or iridium sites along their surface. Our goal is to improve the biocompatibility and long-term performance of the neural prosthetic probes when they are implanted chronically in the brain. In our most recent efforts we have established that electrochemical polymerization can be used to deposit fuzzy coatings of conducting polymers specifically on the electrode sites. For neural prosthetic devices that are intended for long term implantation, we need to develop surfaces that provide intimate contact and promote efficient signal transport at the interface of the microelectrode array and brain tissue. We have developed methods to rapidly and reliably fabricate nanostructured conducting polymer coatings on the electrode probes using templated and surfactant-mediated techniques. Conducting polymer nanomushrooms and nanohairs of polypyrrole (PPy) were electrochemically polymerized onto the functional sites of neural probes by using either nanoporous block copolymers thin films, "track-etched" polycarbonate films or anodic aluminium oxide membranes as templates. Nanofibers of conducting polymers have also been successfully obtained by polymerizations in the presence of surfactants. The influence of current density, monomer concentration, surfactant concentration, and deposition charge on the thickness and morphology of the nanostructured conducting polymer coatings has been studied by optical, scanned probe, scanning electron and transmission electron microscopy. As compared with the normal nodular morphology of polypyrrole, the nanostructured morphologies grown from the neural electrode result in fuzzy coatings with extremely high surface area. The electrical properties of the polymer coatings were studied by Impedance Spectroscopy (IS) and Cyclic Voltammetry

  7. WO3 nanopaticles and PEDOT:PSS/WO3 composite thin films studied for photocatalytic and electrochromic applications

    NASA Astrophysics Data System (ADS)

    Ivanov Boyadjiev, Stefan; Manduca, Bruno; Szűcs, Júlia; Miklós Szilágyi, Imre

    2016-03-01

    WO3 is a widely studied material for electrochromic and photocatalytic applications. In the present study, WO3 nanoparticles with a controlled structure (monoclinic or hexagonal) were obtained by controlled thermal decomposition of hexagonal ammonium tungsten bronze in air at 500 °C and 600 °C, respectively. The formation, morphology, structure and composition of the as-prepared nanoparticles were studied by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX). The photocatalytic activity of the monoclinic and hexagonal WO3 nanoparticles was studied by decomposing methyl orange in aqueous solution under UV light irradiation. In order to study the electrochromic properties of the WO3 nanoparticles, as well to introduce them for self-cleaning photocatalytic surface applications, thin films were prepared from the WO3 particles together with a conductive polymer. For this, PEDOT:PSS was used, which gives excellent opportunities for obtaining transparent and conductive thin films, suitable for both electrochromic and photocatalytic applications. By spin-coating, transparent PEDOT:PSS/WO3 composite thin films were prepared, on which cyclic voltammetry measurements were performed, and the coloring and bleaching states were studied. Our initial results for the PEDOT:PSS/WO3 composite thin films are promising, suggesting that such composites, after further development, might be successfully used in electrochromic devices and photocatalysis.

  8. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices.

    PubMed

    Batra, Nitin M; Patole, Shashikant P; Abdelkader, Ahmed; Anjum, Dalaver H; Deepak, Francis L; Costa, Pedro M F J

    2015-11-01

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  9. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

    NASA Astrophysics Data System (ADS)

    Batra, Nitin M.; Patole, Shashikant P.; Abdelkader, Ahmed; Anjum, Dalaver H.; Deepak, Francis L.; Costa, Pedro M. F. J.

    2015-11-01

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  10. Titanium dioxide thin films deposited by pulsed laser deposition and integration in radio frequency devices: Study of structure, optical and dielectric properties

    NASA Astrophysics Data System (ADS)

    Orlianges, Jean-Christophe; Crunteanu, Aurelian; Pothier, Arnaud; Merle-Mejean, Therese; Blondy, Pierre; Champeaux, Corinne

    2012-12-01

    Titanium dioxide presents a wide range of technological application possibilities due to its dielectric, electrochemical, photocatalytic and optical properties. The three TiO2 allotropic forms: anatase, rutile and brookite are also interesting, since they exhibit different properties, stabilities and growth modes. For instance, rutile has a high dielectric permittivity, of particular interest for the integration as dielectric in components such as microelectromechanical systems (MEMS) for radio frequency (RF) devices. In this study, titanium dioxide thin films are deposited by pulsed laser deposition. Characterizations by Raman spectroscopy and X-ray diffraction show the evolution of the structural properties. Thin films optical properties are investigated using spectroscopic ellipsometry and transmission measurements from UV to IR range. Co-planar waveguide (CPW) devices are fabricated based on these films. Their performances are measured in the RF domain and compared to simulation, leading to relative permittivity values in the range 30-120, showing the potentialities of the deposited material for capacitive switches applications.

  11. Trace H2 O2 -Assisted High-Capacity Tungsten Oxide Electrochromic Batteries with Ultrafast Charging in Seconds.

    PubMed

    Zhao, Jinxiong; Tian, Yuyu; Wang, Zhen; Cong, Shan; Zhou, Di; Zhang, Qingzhu; Yang, Mei; Zhang, Weikun; Geng, Fengxia; Zhao, Zhigang

    2016-06-13

    A recent technological trend in the field of electrochemical energy storage is to integrate energy storage and electrochromism functions in one smart device, which can establish efficient user-device interactions based on a friendly human-readable output. This type of newly born energy storage technology has drawn tremendous attention. However, there is still plenty of room for technological and material innovation, which would allow advancement of the research field. A prototype Al-tungsten oxide electrochromic battery with interactive color-changing behavior is reported. With the assistance of trace amount of H2 O2 , the battery exhibits a specific capacity almost seven times that for the reported electrochromic batteries, up to 429 mAh g(-1) . Fast decoloration of the reduced tungsten oxide affords a very quick charging time of only eight seconds, which possibly comes from an intricate combination of structure and valence state changes of tungsten oxide. This unique combination of features may further advance the development of smart energy storage devices with suitability for user-device interactions.

  12. Trace H2 O2 -Assisted High-Capacity Tungsten Oxide Electrochromic Batteries with Ultrafast Charging in Seconds.

    PubMed

    Zhao, Jinxiong; Tian, Yuyu; Wang, Zhen; Cong, Shan; Zhou, Di; Zhang, Qingzhu; Yang, Mei; Zhang, Weikun; Geng, Fengxia; Zhao, Zhigang

    2016-06-13

    A recent technological trend in the field of electrochemical energy storage is to integrate energy storage and electrochromism functions in one smart device, which can establish efficient user-device interactions based on a friendly human-readable output. This type of newly born energy storage technology has drawn tremendous attention. However, there is still plenty of room for technological and material innovation, which would allow advancement of the research field. A prototype Al-tungsten oxide electrochromic battery with interactive color-changing behavior is reported. With the assistance of trace amount of H2 O2 , the battery exhibits a specific capacity almost seven times that for the reported electrochromic batteries, up to 429 mAh g(-1) . Fast decoloration of the reduced tungsten oxide affords a very quick charging time of only eight seconds, which possibly comes from an intricate combination of structure and valence state changes of tungsten oxide. This unique combination of features may further advance the development of smart energy storage devices with suitability for user-device interactions. PMID:27159245

  13. Ultrahigh-mobility graphene devices from chemical vapor deposition on reusable copper

    PubMed Central

    Banszerus, Luca; Schmitz, Michael; Engels, Stephan; Dauber, Jan; Oellers, Martin; Haupt, Federica; Watanabe, Kenji; Taniguchi, Takashi; Beschoten, Bernd; Stampfer, Christoph

    2015-01-01

    Graphene research has prospered impressively in the past few years, and promising applications such as high-frequency transistors, magnetic field sensors, and flexible optoelectronics are just waiting for a scalable and cost-efficient fabrication technology to produce high-mobility graphene. Although significant progress has been made in chemical vapor deposition (CVD) and epitaxial growth of graphene, the carrier mobility obtained with these techniques is still significantly lower than what is achieved using exfoliated graphene. We show that the quality of CVD-grown graphene depends critically on the used transfer process, and we report on an advanced transfer technique that allows both reusing the copper substrate of the CVD growth and making devices with mobilities as high as 350,000 cm2 V–1 s–1, thus rivaling exfoliated graphene. PMID:26601221

  14. Deposition and resuspension of selected aerosols particles on electrically charged filter materials for respiratory protective devices.

    PubMed

    Makowski, Krzysztof

    2005-01-01

    The primary aim of the study was to analyse the non-steady state of filtration for selected electrostatic filter materials designed for use in respiratory protective devices. The obtained results showed that the filtration process in electrostatic filters was dependent in the main on the following factors: type of the filter material, electrostatic field strength of the material, and the charge of the aerosol. To a lesser degree the filtration process depended on the sign of the charge and the relative humidity of the air. A significant correlation was found between the increase in the penetration and the decrease in breathing resistance while the filter was being loaded. The effect of resuspension (tearing off and re-deposition of dust agglomerates inside the filter) on the filtration process very significant. It was also observed that under certain conditions electrostatic filter materials lost their protection properties.

  15. In situ process diagnostics of silane plasma for device-quality a-Si:H deposition

    NASA Astrophysics Data System (ADS)

    Shing, Y. H.; Perry, J. W.; Hermann, A. M.

    Coherent anti-Stokes Raman spectroscopy (CARS) and mass spectrometry (MS) have been applied to in situ process diagnostics of a silane plasma for device-quality a-Si:H film deposition. Silane depletion was directly measured by CARS and is linearly dependent on RF power in the region of 4-12 W with a slope of 0.5 percent/mW-sq cm. The depletion is also dependent on SiH4 flow rate starting with a 50 percent depletion at a low flow rate of 5.6 sccm and asymptotically approaching an 8 percent depletion at a flow rate of 80 sccm. The mass spectral line signal intensity of disilane increases with RF power and shows an apparent transition at 6 W. Disilane formation in silane plasma, film deposition rate, and silane depletion ratio as a function of the RF power indicate that the film growth mechanism in the low-power region of 3.5-6.5 W is substantially different from that in the high-power region of 6.5-12 W.

  16. In situ process diagnostics of silane plasma for device-quality a-Si:H deposition

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.; Perry, J. W.; Hermann, A. M.

    1987-01-01

    Coherent anti-Stokes Raman spectroscopy (CARS) and mass spectrometry (MS) have been applied to in situ process diagnostics of a silane plasma for device-quality a-Si:H film deposition. Silane depletion was directly measured by CARS and is linearly dependent on RF power in the region of 4-12 W with a slope of 0.5 percent/mW-sq cm. The depletion is also dependent on SiH4 flow rate starting with a 50 percent depletion at a low flow rate of 5.6 sccm and asymptotically approaching an 8 percent depletion at a flow rate of 80 sccm. The mass spectral line signal intensity of disilane increases with RF power and shows an apparent transition at 6 W. Disilane formation in silane plasma, film deposition rate, and silane depletion ratio as a function of the RF power indicate that the film growth mechanism in the low-power region of 3.5-6.5 W is substantially different from that in the high-power region of 6.5-12 W.

  17. Electrospray-assisted characterization and deposition of chlorosomes to fabricate a biomimetic light-harvesting device

    SciTech Connect

    Modesto-Lopez, Luis B.; Thimsen, Elijah J.; Collins, Aaron M.; Blankenship, R. E.; Biswas, Pratim

    2010-01-01

    Photosynthesis is an efficient process by which solar energy is converted into chemical energy. Green photosynthetic bacteria such as Chloroflexus aurantiacus have supramolecular antenna complexes called chlorosomes attached to their cytoplasmic membrane that increase the cross section for light absorption even in low-light conditions. Self-assembled bacteriochlorophyll pigments in the chlorosome interior play a key role in the efficient transfer and funneling of the harvested energy. In this work it was demonstrated that chlorosomes can be rapidly and precisely size-characterized online in real time using an electrospray-assisted mobility-based technique. Chlorosomes were electrospray-deposited onto TiO{sub 2} nanostructured films with columnar morphology to fabricate a novel biomimetic device to overcome the solvent compatibility issues associated with biological particles and synthetic dyes. The assembled unit retained the viability of the chlorosomes, and the harvesting of sunlight over a broader range of wavelengths was demonstrated. It was shown that the presence of chlorosomes in the biomimetic device had a 30-fold increase in photocurrent.

  18. Heteroepitaxial growth of 3-5 semiconductor compounds by metal-organic chemical vapor deposition for device applications

    NASA Technical Reports Server (NTRS)

    Collis, Ward J.; Abul-Fadl, Ali

    1988-01-01

    The purpose of this research is to design, install and operate a metal-organic chemical vapor deposition system which is to be used for the epitaxial growth of 3-5 semiconductor binary compounds, and ternary and quaternary alloys. The long-term goal is to utilize this vapor phase deposition in conjunction with existing current controlled liquid phase epitaxy facilities to perform hybrid growth sequences for fabricating integrated optoelectronic devices.

  19. Increased Stabilized Performance Of Amorphous Silicon Based Devices Produced By Highly Hydrogen Diluted Lower Temperature Plasma Deposition.

    DOEpatents

    Li, Yaun-Min; Bennett, Murray S.; Yang, Liyou

    1997-07-08

    High quality, stable photovoltaic and electronic amorphous silicon devices which effectively resist light-induced degradation and current-induced degradation, are produced by a special plasma deposition process. Powerful, efficient single and multi-junction solar cells with high open circuit voltages and fill factors and with wider bandgaps, can be economically fabricated by the special plasma deposition process. The preferred process includes relatively low temperature, high pressure, glow discharge of silane in the presence of a high concentration of hydrogen gas.

  20. Increasing Stabilized Performance Of Amorphous Silicon Based Devices Produced By Highly Hydrogen Diluted Lower Temperature Plasma Deposition.

    DOEpatents

    Li, Yaun-Min; Bennett, Murray S.; Yang, Liyou

    1999-08-24

    High quality, stable photovoltaic and electronic amorphous silicon devices which effectively resist light-induced degradation and current-induced degradation, are produced by a special plasma deposition process. Powerful, efficient single and multi-junction solar cells with high open circuit voltages and fill factors and with wider bandgaps, can be economically fabricated by the special plasma deposition process. The preferred process includes relatively low temperature, high pressure, glow discharge of silane in the presence of a high concentration of hydrogen gas.

  1. Preparation of UV curing crosslinked polyviologen film and its photochromic and electrochromic performances

    NASA Astrophysics Data System (ADS)

    Gao, Li-ping; Ding, Guo-jing; Wang, Yue-chuan; Yang, Yu-lin

    2011-11-01

    Polyether urethane diacrylate matrix (PEUDA) and acrylate-functional viologen (ACV2+) were successfully synthesized and characterized in detail by FTIR and 1H NMR spectra, respectively. Subsequently, they were used to prepare UV curing crosslinked polyviologen film in combination with 2-hydroxyethyl methacrylate (HEMA), trimethylolpropane ethoxylate triacrylate (TMPTA) and diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO). UV curing approach confined the polyviologen film on ITO electrode, which imparted the film excellent adhesion ability to ITO glass, good solvent resistance, excellent chemical stability, excellent optical and electrochemical properties. The crosslinked PACV2+ film exhibited excellent photochromic and electrochromic performances. After UV illumination for 60 s, the crosslinked PACV2+ film can swiftly change its color from pale yellow to deep blue, while the optical transmission of crosslinked PACV2+ film at 610 nm did not change significantly and still retained about 63.6% after 30 cycles. Simultaneously, the cyclic voltammetry experiment showed the PACV2+ film can undergo repeatable electrochemical redox reactions with good reversibility beyond the 10th scan. Furthermore, the electrochromic device composed of the PACV2+ film and gel electrolyte film can undergo reversible color change in response to the external voltages of -2.0 V and 2.0 V, respectively, while the contrast of EC device at 610 nm did not change significantly and still retained about 39.5% after 10 cycles. This UV curing approach to preparing viologen-functional film offers a method to preparing large-scale photo- and electrochromic device, which is relatively simple, high productivity, energy saving, and environmental protection.

  2. Preparation and characterization of nanothermite inks for direct deposition on initiation devices

    NASA Astrophysics Data System (ADS)

    Nellums, Robert R.

    Nanothermites show promise as a replacement for energetic materials in many devices but their use has been limited by high sensitivity during processing, hazardous processing solvents, and time consuming deposition. Incorporating processing and deposition into a single step, especially if no organic solvents were used, could allow nanothermites to be applied in a wider range of applications. First, this work reports on the performance and mixing quality of nanothermites prepared in a LabRAM resonant mixer at high solids loadings as compared to traditional ultrasonic mixing. Specifically, the aluminum-bismuth (III) oxide (Al/Bi2O3) system processed in N,N-dimethylformamide (DMF) was investigated. It was found that the performance and quality of mixing were correlated to the volumetric solids loading during processing; increasing volumetric solids loading decreases separation of particles, leading to more intimate mixing. The measured performance of this system processed in DMF at 30 vol.% was similar to traditionally sonicated mixtures in hexanes, uses significantly less solvent, results in a higher density final material, and can be scaled. Second, this work investigates the replacement of the processing solvent DMF with water. Processing safety was characterized by measurement of thermal rise during mixing, stability at elevated temperature, and electrostatic discharge (ESD) sensitivity. Mixture performance was characterized via semi-conductor bridge (SCB) ignition threshold, Parr cell ignition delay and Parr cell pressurization rate. It was found that nanothermites processed in water performed similarly to nanothermites processed in DMF, although secondary interactions between aluminum and water caused heating that could be dangerous in scaled nanothermite batches. This secondary interaction was eliminated by coating both metal and metal oxide with an organic acid. In addition, processing in water at a solids loading of 30 vol.% resulted in a high performance ink

  3. Electrochromic thin films from a redox active diarylethene by electrochemical polymerization.

    PubMed

    Yun, Chijung; Seo, Seogjae; Kim, Eunkyoung

    2010-10-01

    A diarylethene substituted with 3,4-(propane-1,3-diyldioxy)thiophene (ProDOT) was synthesized to induce electrochemical deposition of diarylethenes. The ProDOT substituted diarylethene (BTFPP) showed reversible photochromism from colorless to purple upon exposure to a UV light and bleached to colorless by a visibly light. The oxidation potential of the new ProDOT substituted diarylethene was lower than that of the unsubstituted diarylethenes due to the electroactive ProDOT unit. Under an electrochemical condition, the solution of BTFPP gave soluble polymers but deposited insoluble film on a working electrode coated with a PEDOT layer. This result indicates that the PEDOT nano layer (68 nm thick) function as a seeding layer to induce polymerization and electrodeposition of BTFPP. Furthermore electro-copolymerization using a mixture of BTFPP and EDOT afforded electrodeposition of the copolymers on the PEDOT seeding layer. An electrochromic electrode was successfully fabricated by depositing the photochromic BTFPP on an ITO glass, which shows a reversible electrochromic change from violet to sky blue. PMID:21137810

  4. Electrochromic thin films from a redox active diarylethene by electrochemical polymerization.

    PubMed

    Yun, Chijung; Seo, Seogjae; Kim, Eunkyoung

    2010-10-01

    A diarylethene substituted with 3,4-(propane-1,3-diyldioxy)thiophene (ProDOT) was synthesized to induce electrochemical deposition of diarylethenes. The ProDOT substituted diarylethene (BTFPP) showed reversible photochromism from colorless to purple upon exposure to a UV light and bleached to colorless by a visibly light. The oxidation potential of the new ProDOT substituted diarylethene was lower than that of the unsubstituted diarylethenes due to the electroactive ProDOT unit. Under an electrochemical condition, the solution of BTFPP gave soluble polymers but deposited insoluble film on a working electrode coated with a PEDOT layer. This result indicates that the PEDOT nano layer (68 nm thick) function as a seeding layer to induce polymerization and electrodeposition of BTFPP. Furthermore electro-copolymerization using a mixture of BTFPP and EDOT afforded electrodeposition of the copolymers on the PEDOT seeding layer. An electrochromic electrode was successfully fabricated by depositing the photochromic BTFPP on an ITO glass, which shows a reversible electrochromic change from violet to sky blue.

  5. Evaluation criteria and test methods for electrochromic windows

    SciTech Connect

    Czanderna, A.W. ); Lampert, C.M. )

    1990-07-01

    Report summarizes the test methods used for evaluating electrochromic (EC) windows, and summarizes what is known about degradation of their performance, and recommends methods and procedures for advancing EC windows for buildings applications. 77 refs., 13 figs., 6 tabs.

  6. Effects of Plasma Polymer Films and Their Deposition Powers on the Barrier Characteristics of the Multilayer Encapsulation for Organic Devices.

    PubMed

    Kim, Hoonbae; Ban, Wonjin; Kwon, Sungruel; Yong, Sanghyun; Chae, Heeyeop; Jung, Donggeun

    2016-05-01

    Organic electronic devices (OEDs) are quite suitable for use in flexible devices due to their ruggedness and flexibility. A number of researchers have studied the use of OEDs on flexible substrates in transparent, flexible devices in the near future. However, water and oxygen can permeate through the flexible substrates and can reduce the longevity of OEDs made from organic materials, which are weak to moisture and oxygen. In order to prevent the degradation of the OEDs, researchers have applied an encapsulation layer to the flexible substrates. In this study, Al2O3/plasma polymer film/Al2O3 multi-layers were deposited on polyethylene-naphthalate substrates through a combination of atomic layer deposition and plasma-enhanced chemical vapor deposition (PECVD). The plasma polymer film, which is located between the Al2O3 films, is deposited via PECVD with the use of a tetrakis(trimethylsilyloxy)silane precursor. The power of the plasma deposition varied from 10 to 50 W. The hydrophobicity of the plasma polymer film surfaces was investigated by measuring the water contact angle. The chemical structures of the plasma polymer films were measured via ex-situ Fourier transform infrared analysis. The permeation curves of the various films were analyzed by performing a calcium (Ca)-test. PMID:27483936

  7. Electronic and optical properties of tungsten oxide related materials and first-principles theory of electrochromism

    NASA Astrophysics Data System (ADS)

    Xue, Yu

    Tungsten trioxide WO3 is an interesting semiconductor with a wide-range of potential applications. One important property of WO 3 is its electrochromic behavior, which has generated significant research interest. Electrochromic materials exhibit reversible and persistent changes of the optical properties, hence their color, upon applying an electrical pulse. The applications of the electrochromic WO3 range from information display, light shutters, to energy efficient smart windows. Although there are many materials that exhibit electrochromic behavior, tungsten trioxide is one of the most extensively studied ones due to its superior coloration efficiency, short response time and reversibility. Enhanced electrochromic properties in WO3 nanowires have been reported recently. Despite much research effort, a first-principles theory for the coloration mechanism in this material has not emerged. In this work, we establish a first-principles theory for the coloration mechanism in NaxWOx, which is also able to explain the electrochromism in WO3. Chapter 1 gives a brief introduction to electrochromism in WO3 and related materials. In Chapter 2, we summarize the theories and computational methods used in this work including the local density approximation (LDA) within density functional theory (DFT), pseudopotential planewave formalism and the GW approximation. We study the crystal and electronic structures of WO3 in Chapter 3. WO3 has a basic octahedron structure. From -140 ˜ 830°C, the crystal structure changes from monoclinic to triclinic, again monoclicnic, then successively orthorhombic, tetragonal, and again tetragonal. Several groups have investigated the electronic structure of WO3 within DFT, but the band gap is severely underestimated compared with experiment. We have carried out quasiparticle calculations within the GW approximation. The calculated band gap is much closer to experimental results. Chapter 4 and Chapter 5 discuss the optical properties and

  8. Evaluation of integrated wall systems incorporating electrochromic windows [Final report

    SciTech Connect

    Sbar, Neil L.

    2001-03-30

    Billions of dollars are spent annually in the U.S. on energy lost through the use of inefficient windows. Even wall systems with advanced static glazings and moveable shading devices are not optimal because they can't effectively respond to changing solar conditions. Electrochromic (EC) smart windows can dynamically control the amount of solar light and heat entering a building. The energy saving performance of fully dynamic wall systems containing EC windows was compared with that of static systems using the DOE 2.1E building simulation program. Total costs for different scenarios were computed. SAGE demonstrated the capability to produce double pane EC windows in which the transmittance repeatedly varied between 2-58%. Relative impact of EC glazings in buildings compared to static is 10-20% energy savings across all climatic regions investigated. Significant life cycle cost savings are predicted for SAGE's EC windows when compared to conventional solar control windows over an estimated product lifetime of 20 years.

  9. Opportunities and challenges in GaN metal organic chemical vapor deposition for electron devices

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koh; Yamaoka, Yuya; Ubukata, Akinori; Arimura, Tadanobu; Piao, Guanxi; Yano, Yoshiki; Tokunaga, Hiroki; Tabuchi, Toshiya

    2016-05-01

    The current situation and next challenge in GaN metal organic chemical vapor deposition (MOCVD) for electron devices of both GaN on Si and GaN on GaN are presented. We have examined the possibility of increasing the growth rate of GaN on 200-mm-diameter Si by using a multiwafer production MOCVD machine, in which the vapor phase parasitic reaction is well controlled. The impact of a high-growth-rate strained-layer-superlattice (SLS) buffer layer is presented in terms of material properties. An SLS growth rate of as high as 3.46 µm/h, which was 73% higher than the current optimum, was demonstrated. As a result, comparable material properties were obtained. Next, a typical result of GaN doped with Si of 1 × 1016 cm-3 grown at the growth rate of 3.7 µm/h is shown. For high-voltage application, we need a thick high-purity GaN drift layer with a low carbon concentration, of less than 1016 cm-3. It is shown that achieving a high growth rate by precise control of the vapor phase reaction is still challenge in GaN MOCVD.

  10. Atomic layer deposited aluminum oxide and Parylene C bi-layer encapsulation for biomedical implantable devices

    NASA Astrophysics Data System (ADS)

    Xie, Xianzong

    Biomedical implantable devices have been developed for both research and clinical applications, to stimulate and record physiological signals in vivo. Chronic use of biomedical devices with thin-film-based encapsulation in large scale is impeded by their lack of long-term functionality and stability. Biostable, biocompatible, conformal, and electrically insulating coatings that sustain chronic implantation are essential for chip-scale implantable electronic systems. Even though many materials have been studied to for this purpose, to date, no encapsulation method has been thoroughly characterized or qualified as a broadly applicable long-term hermetic encapsulation for biomedical implantable devices. In this work, atomic layer deposited Al2O3 and Parylene C bi-layer was investigated as encapsulation for biomedical devices. The combination of ALD Al2O3 and CVD Parylene C encapsulation extended the lifetime of coated interdigitated electrodes (IDEs) to up to 72 months (to date) with low leakage current of ~ 15 pA. The long lifetime was achieved by significantly reducing moisture permeation due to the ALD Al2O3 layer. Moreover, the bi-layer encapsulation separates the permeated moisture (mostly at the Al2O3 and Parylene interface) from the surface contaminants (mostly at the device and Al 2O3 interface), preventing the formation of localized electrolyte through condensation. Al2O3 works as an inner moisture barrier and Parylene works as an external ion barrier, preventing contact of Al2O3 with liquid water, and slowing the kinetics of alumina corrosion. Selective removal of encapsulation materials is required to expose the active sites for interacting with physiological environment. A self-aligned mask process with three steps was developed to expose active sites, composed of laser ablation, oxygen plasma etching, and BOE etching. Al2O 3 layer was found to prevent the formation of microcracks in the iridium oxide film during laser ablation. Bi-layer encapsulated

  11. Germanium-on-Silicon Strain Engineered Materials for Improved Device Performance Grown by Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Bharathan, Jayesh Moorkoth

    The primary goal of this research is to develop a chemical vapor deposition process for growing epitaxial films of germanium on silicon (001) substrates with two-dimensional (2-D) morphology, and a low density of threading dislocations. Growth was carried out in a reduced-pressure chemical vapor deposition (RPCVD) system by a two-step growth technique. An accurate knowledge of elastic constants of thin films is important in understanding the effect of strain on material properties. Residual thermal strain was used to measure the Poisson ratio of Ge films grown on Si(001) substrates, by the sin2Psi method and highresolution x-ray diffraction. The Poisson ratio of the Ge films was measured to be 0.25, compared to the bulk value of 0.27. The result was found to be independent of film thickness and defect density, which confirmed that the strain is associated with the elastic response of the film. The study showed that the use of Poisson ratio instead of bulk compliance values yields a more accurate description of the state of in-plane strain present in the film. The experimentally measured in-plane strain in Ge films was found to be lower than the theoretical calculations based on the differential thermal expansion coefficients of Si and Ge. The mechanism of thermal misfit strain relaxation in epitaxial Ge films grown on Si(001) substrates was investigated by x-ray diffraction, and transmission electron microscopy. Lattice misfit strain associated with Ge/(001)Si mismatched epitaxy is relieved by a network of Lomer edge misfit dislocations during the first step of the growth technique. However, thermal misfit strain energy during growth is relieved by interdiffusion mechanism at the heterointerface. Two SiGe compositions containing 0.5 and 6.0 atomic percent Si were detected that relieve the thermal mismatch strain associated with the two steps of the growth process. This study discusses the importance of interdiffusion mechanism in relieving small misfit strains

  12. Electrochromism and photocatalysis in dendrite structured Ti:WO3 thin films grown by sputtering

    NASA Astrophysics Data System (ADS)

    Karuppasamy, A.

    2015-12-01

    Titanium doped tungsten oxide (Ti:WO3) thin films with dendrite surface structures were grown by co-sputtering titanium and tungsten in Ar + O2 atmosphere. Ti:WO3 thin films were deposited at oxygen flow rates corresponding to pressures in the range 1.0 × 10-3-5.0 × 10-3 mbar. Argon flow rate and sputtering power densities for titanium (2 W/cm2) and tungsten (3 W/cm2) were kept constant. Ti:WO3 films deposited at an oxygen pressure of 5 × 10-3 mbar are found to be better electrochromic and photocatalytic. They have high optical modulation (80% at λ = 550 nm), coloration efficiency (60 cm2/C at λ = 550 nm), electron/ion storage and removal capacity (Qc: -22.01 mC/cm2, Qa: 17.72 mC/cm2), reversibility (80%) and methylene blue decomposition rate (-1.38 μmol/l d). The combined effects of titanium doping, dendrite surface structures and porosity leads to significant enhancement in the electrochromic and photocatalytic properties of Ti:WO3 films.

  13. RF Magnetron Sputtering Deposited W/Ti Thin Film For Smart Window Applications

    NASA Astrophysics Data System (ADS)

    Oksuz, Lutfi; Kiristi, Melek; Bozduman, Ferhat; Uygun Oksuz, Aysegul

    2014-10-01

    Electrochromic (EC) devices can change reversible and persistent their optical properties in the visible region (400-800 nm) upon charge insertion/extraction according to the applied voltage. A complementary type EC is a device containing two electrochromic layers, one of which is anodically colored such as vanadium oxide (V2 O5) while the other cathodically colored such as tungsten oxide (WO3) which is separated by an ionic conduction layer (electrolyte). The use of a solid electrolyte such as Nafion eliminates the need for containment of the liquid electrolyte, which simplifies the cell design, as well as improves safety and durability. In this work, the EC device was fabricated on a ITO/glass slide. The WO3-TiO2 thin film was deposited by reactive RF magnetron sputtering using a 2-in W/Ti (9:1%wt) target with purity of 99.9% in a mixture gas of argon and oxygen. As a counter electrode layer, V2O5 film was deposited on an ITO/glass substrate using V2O3 target with the same conditions of reactive RF magnetron sputtering. Modified Nafion was used as an electrolyte to complete EC device. The transmittance spectra of the complementary EC device was measured by optical spectrophotometry when a voltage of +/-3 V was applied to the EC device by computer controlled system. The surface morphology of the films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig. 2). The cyclic voltammetry (CV) for EC device was performed by sweeping the potential between +/-3 V at a scan rate of 50 mV/s.

  14. Electrical transport and low-frequency noise in chemical vapor deposited single-layer MoS2 devices

    NASA Astrophysics Data System (ADS)

    Sharma, Deepak; Amani, Matin; Motayed, Abhishek; Shah, Pankaj B.; Birdwell, A. Glen; Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun; Dubey, Madan; Li, Qiliang; Davydov, Albert V.

    2014-04-01

    We have studied temperature-dependent (77-300 K) electrical characteristics and low-frequency noise (LFN) in chemical vapor deposited (CVD) single-layer molybdenum disulfide (MoS2) based back-gated field-effect transistors (FETs). Electrical characterization and LFN measurements were conducted on MoS2 FETs with Al2O3 top-surface passivation. We also studied the effect of top-surface passivation etching on the electrical characteristics of the device. Significant decrease in channel current and transconductance was observed in these devices after the Al2O3 passivation etching. For passivated devices, the two-terminal resistance variation with temperature showed a good fit to the activation energy model, whereas for the etched devices the trend indicated a hopping transport mechanism. A significant increase in the normalized drain current noise power spectral density (PSD) was observed after the etching of the top passivation layer. The observed channel current noise was explained using a standard unified model incorporating carrier number fluctuation and correlated surface mobility fluctuation mechanisms. Detailed analysis of the gate-referred noise voltage PSD indicated the presence of different trapping states in passivated devices when compared to the etched devices. Etched devices showed weak temperature dependence of the channel current noise, whereas passivated devices exhibited near-linear temperature dependence.

  15. Electrical transport and low-frequency noise in chemical vapor deposited single-layer MoS2 devices.

    PubMed

    Sharma, Deepak; Amani, Matin; Motayed, Abhishek; Shah, Pankaj B; Birdwell, A Glen; Najmaei, Sina; Ajayan, Pulickel M; Lou, Jun; Dubey, Madan; Li, Qiliang; Davydov, Albert V

    2014-04-18

    We have studied temperature-dependent (77-300 K) electrical characteristics and low-frequency noise (LFN) in chemical vapor deposited (CVD) single-layer molybdenum disulfide (MoS2) based back-gated field-effect transistors (FETs). Electrical characterization and LFN measurements were conducted on MoS2 FETs with Al2O3 top-surface passivation. We also studied the effect of top-surface passivation etching on the electrical characteristics of the device. Significant decrease in channel current and transconductance was observed in these devices after the Al2O3 passivation etching. For passivated devices, the two-terminal resistance variation with temperature showed a good fit to the activation energy model, whereas for the etched devices the trend indicated a hopping transport mechanism. A significant increase in the normalized drain current noise power spectral density (PSD) was observed after the etching of the top passivation layer. The observed channel current noise was explained using a standard unified model incorporating carrier number fluctuation and correlated surface mobility fluctuation mechanisms. Detailed analysis of the gate-referred noise voltage PSD indicated the presence of different trapping states in passivated devices when compared to the etched devices. Etched devices showed weak temperature dependence of the channel current noise, whereas passivated devices exhibited near-linear temperature dependence. PMID:24642948

  16. Deposition of Chromium Thin Films on Stainless Steel-304 Substrates Using a Low Energy Plasma Focus Device

    NASA Astrophysics Data System (ADS)

    Javadi, S.; Ghoranneviss, M.; Hojabri, A.; Habibi, M.; Hosseinnejad, M. T.

    2012-06-01

    In this paper, we study thin films of chromium deposited on stainless steel-304 substrates using a low energy (1.6 kJ) plasma focus device. The films of chromium are likewise deposited with 25 focus shots each at various axial distances from the top of the anode (3, 5, 7, 9 and 11 cm). We also consider different angular positions with respect to the anode axis (0°, 15° and 30°) at a distance of 5 cm from the anode tip to deposit the chromium films on the stainless steel substrates. To characterize the structural properties of the films, we benefit from X-ray diffraction (XRD) analysis. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are applied as well to study the surface morphology of these deposited films. Furthermore, we make use of Vicker's micro-hardness measurements to investigate the mechanical properties of chromium thin films. The XRD results show that the degree of crystallinity of chromium thin films depends on the substrate axial and angular positions. The AFM images illustrate that the film deposited at the distance of 5 cm and the angular position of 0° has quite a uniform surface with homogeneous distribution of grains on the film surface. From the hardness results, we observe that the sample deposited at the axial distance of 5 cm from the anode tip and at the angle of 0° with respect to the anode axis, is harder than the other deposited films.

  17. Guiding neuron development with planar surface gradients of substrate cues deposited using microfluidic devices

    PubMed Central

    Millet, Larry J.; Stewart, Matthew E.; Nuzzo, Ralph G.

    2010-01-01

    Wiring the nervous system relies on the interplay of intrinsic and extrinsic signaling molecules that control neurite extension, neuronal polarity, process maturation and experience-dependent refinement. Extrinsic signals establish and enrich neuron-neuron interactions during development. Understanding how such extrinsic cues direct neurons to establish neural connections in vitro will facilitate the development of organised neural networks for investigating the development and function of nervous system networks. Producing ordered networks of neurons with defined connectivity in vitro presents special technical challenges because the results must be compliant with the biological requirements of rewiring neural networks. Here we demonstrate the ability to form stable, instructive surface-bound gradients of laminin that guide postnatal hippocampal neuron development in vitro. Our work uses a three-channel, interconnected microfluidic device that permits the production of adlayers of planar substrates through the combination of laminar flow, diffusion and physisorption. Through simple flow modifications, a variety of patterns and gradients of laminin (LN) and flourescein-conjugated poly-lysine (FITC-PLL) were deposited to present neurons with an instructive substratum to guide neuronal development. We present three variations in substrate design that produce distinct growth regimens for postnatal neurons in dispersed cell cultures. In the first approach, diffusion-mediated gradients of LN were formed on coverslips to guide neurons toward increasing LN concentrations. In the second approach, a combined gradient of LN and FITC-PLL was produced using aspiration-driven laminar flow to restrict neuronal growth to a 15 μm-wide growth zone at the center of the two superimposed gradients. The last approach demonstrates the capacity to combine binary lines of FITC-PLL in conjunction with surface gradients of LN and bovine serum albumin (BSA) to produce substrate adlayers

  18. A redox-flow electrochromic window.

    PubMed

    Jennings, James R; Lim, Wei Yang; Zakeeruddin, Shaik M; Grätzel, Michael; Wang, Qing

    2015-02-01

    A low-cost electrochromic (EC) window based on a redox-flow system that does not require expensive transparent conductive oxide (TCO) substrates is introduced and demonstrated for the first time. An aqueous I3–/I– redox electrolyte is used in place of a TCO to oxidize/reduce a molecular layer of an EC triphenylamine derivative that is anchored to a mesoporous TiO2 scaffold on the inner faces of a double-paned window. The redox electrolyte is electrochemically oxidized/reduced in an external two-compartment cell and circulated through the window cavity using an inexpensive peristaltic pump, resulting in coloration or decoloration of the window due to reaction of the redox solution with the triphenylamine derivative. The absorption characteristics, coloration/decoloration times, and cycling stability of the prototype EC window are evaluated, and prospects for further development are discussed. PMID:25584903

  19. PECVD/ECR/HWCVD Multichamber System with Robotic Substrate Handling System for deposition of Thin Film Electronic Devices

    NASA Astrophysics Data System (ADS)

    Rava, P.

    2012-11-01

    The present work reports on progress in the design of modular UHV cluster tool multichamber systems. A wide range of processes has been implemented in the Deposition Process Chambers (DPC's), including rf-PECVD, vhf-PECVD, ECR-PECVD and HWCVD. A wide range of intrinsic and doped amorphous and microcrystalline silicon and silicon alloy materials have been produced and have been used in the fabrication of several types of electronic devices such as solar cells, Light Emitting Devices (LED's), Thin Film Transistors (TFT's), etc. using multichamber systems at several laboratories worldwide.

  20. Vapor deposition of cross-linked fluoropolymer barrier coatings onto pre-assembled microfluidic devices.

    PubMed

    Riche, Carson T; Marin, Brandon C; Malmstadt, Noah; Gupta, Malancha

    2011-09-21

    The interior surfaces of pre-assembled poly(dimethylsiloxane) (PDMS) microfluidic devices were modified with a cross-linked fluoropolymer barrier coating that significantly increased the chemical compatibility of the devices. PMID:21850298

  1. Electrochromic enhancement of latent fingerprints by poly(3,4-ethylenedioxythiophene).

    PubMed

    Brown, Rachel M; Hillman, A Robert

    2012-06-28

    Spatially selective electrodeposition of poly-3,4-ethylenedioxythiophene (PEDOT) thin films on metallic surfaces is shown to be an effective means of visualizing latent fingerprints. The technique exploits the fingerprint deposit as an insulating mask, such that electrochemical processes (here, polymer deposition) may only take place on deposit-free areas of the surface between the ridges of the fingerprint deposit; the end result is a negative image of the fingermark. Use of a surfactant (sodium dodecylsulphate, SDS) to solubilise the EDOT monomer allows the use of an aqueous electrolyte. Electrochemical (coulometric) data provide a total assay of deposited material, yielding spatially averaged film thicknesses, which are commensurate with substantive filling of the trenches between fingerprint deposit ridges, but not overfilling to the extent that the ridge detail is covered. This is confirmed by optical microscopy and AFM images, which show continuous polymer deposition within the trenches and good definition at the ridge edges. Stainless steel substrates treated in this manner and transferred to background electrolyte (aqueous sulphuric acid) showed enhanced fingerprints when the contrast between the polymer background and fingerprint deposit was optimised using the electrochromic properties of the PEDOT films. The facility of the method to reveal fingerprints of various ages and subjected to plausible environmental histories was demonstrated. Comparison of this enhancement methodology with commonly used fingerprint enhancement methods (dusting with powder, application of wet powder suspensions and cyanoacrylate fuming) showed promising performance in selected scenarios of practical interest.

  2. Development of a microbalance suitable for space application. [mass measurement device for particulate and vapor deposition measurements

    NASA Technical Reports Server (NTRS)

    Patashnick, H.; Rupprecht, G.

    1977-01-01

    The tapered element oscillating microbalance (TEOM), an ultrasensitive mass measurement device which is suitable for both particulate and vapor deposition measurements is described. The device can be used in contamination measurements, surface reaction studies, particulate monitoring systems or any microweighing activity where either laboratory or field monitoring capability is desired. The active element of the TEOM consists of a tube or reed constructed of a material with high mechanical quality factor and having a special taper. The element is firmly mounted at the wide end while the other end supports a substrate surface which can be composed of virtually any material. The tapered element with the substrate at the free (narrow) end is set into oscillation in a clamped free mode. A feedback system maintains the oscillation whose natural frequency will change in relation to the mass deposited on the substrate.

  3. Large-area electrochromic coatings: Composites of polyaniline and polyacrylate-silica hybrid sol-gel materials

    SciTech Connect

    Jang, G.W.; Chen, C.; Gumbs, R.W.; Wei, Y.; Yeh, J.M.

    1996-08-01

    A low-cost technique for fabricating large-area electrochromic coatings is described. Polyaniline was incorporated into polyacrylate-silica hybrid sol-gel networks using suspended particles or solutions. A solution of polyaniline and poly[methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate] can be spray- or brush-coated on transparent indium-tin oxide substrates to form robust electrochromic coatings. Silane functional groups on the polyacrylate chain act as coupling and cross-linking agents to improve surface adhesion and mechanical properties of the resulting composite coatings. These coatings showed reversible transparent to green color change when polarized at potentials between {minus}0.4 and +0.4 V vs. Ag/AgCl in a 0.2 M LiClO{sub 4}/acetonitrile electrolyte solution. The cycle lifetimes of polyaniline films were improved by incorporating the polymer in the polyacrylate-silica matrix. Electrochromic switching was demonstrated for the composite coatings in large-area all-solid-state devices.

  4. Spray Chemical Vapor Deposition of CulnS2 Thin Films for Application in Solar Cell Devices

    NASA Technical Reports Server (NTRS)

    Hollingsworth, Jennifer A.; Buhro, William E.; Hepp, Aloysius F.; Jenkins. Philip P.; Stan, Mark A.

    1998-01-01

    Chalcopyrite CuInS2 is a direct band gap semiconductor (1.5 eV) that has potential applications in photovoltaic thin film and photoelectrochemical devices. We have successfully employed spray chemical vapor deposition using the previously known, single-source, metalorganic precursor, (Ph3P)2CuIn(SEt)4, to deposit CuInS2 thin films. Stoichiometric, polycrystalline films were deposited onto fused silica over a range of temperatures (300-400 C). Morphology was observed to vary with temperature: spheroidal features were obtained at lower temperatures and angular features at 400 C. At even higher temperatures (500 C), a Cu-deficient phase, CuIn5S8, was obtained as a single phase. The CuInS2 films were determined to have a direct band gap of ca. 1.4 eV.

  5. Durable electrooptic devices comprising ionic liquids

    SciTech Connect

    Agrawal, Anoop; Cronin, John P.; Tonazzi, Juan C. L.; Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.

    2005-11-01

    Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF3SO3-), bis(trifluoromethylsulfonyl)imide ((CF3SO2)2N-), bis(perfluoroethylsulfonyl)imide ((CF3CF2SO2)2N-) and tris(trifluoromethylsulfonyl)methide ((CF3SO2)3C-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes.

  6. Electrochromic materials for controlled radiant energy transfer in buildings: Final technical summary of research, 2 August 1982--31 October 1985

    SciTech Connect

    Goldner, R.B.

    1986-01-01

    Electrically controlled variable reflectivity electrochromic windows have the potential to significantly reduce heating, cooling, and lighting loads in buildings. The theoretical and experimental research at Tufs during this contract has led to improved modeling and understanding of the properties of thin polycrystalline films of WO/sub 3/ the presently leading candidate for the electrochromic layer of solid-state smart window structure. The research has shown that LiAlF/sub 4/ is a good ion-conducting and electron-insulating material which may be suitable for use as the ion conductor layer in a lithium based electrochromic structure. The research has identified the materials indium oxide (In/sub 2/O/sub 3/) and tin-doped indium oxide as potential ion-insertion material and thus candidates for the counterelectrode (EC) layer as well as the transparent conductor layer of these devices. The research to date demonstrated that it is highly likely that an all-soild-state-thin-film electrochromic smart window can be developed, in the near future. Further important fundamental research needs to be done before a full-fledged development effort is initiated. 17 refs.

  7. The effect of substrate temperature on material properties and the device performance of close-spaced sublimation deposited CdTe/CdS devices

    NASA Astrophysics Data System (ADS)

    Li, X.; Albin, D.; Asher, S.; Moutinho, H.; Keyes, B.; Matson, R.; Hasoon, F.; Sheldon, P.

    1996-01-01

    High-efficiency polycrystalline CdS/CdTe solar cells have been fabricated using CdTe absorber layers deposited by close-spaced sublimation (CSS). CSS employs high substrate temperatures (Tsub) during film growth, which can promote the formation of larger grains and higher Voc's yielding better device performance. However, as Tsub increases beyond 610 °C, voids or pinholes begin to form in the CdTe layer. When the back contact is applied, these voids serve as shunt paths that effectively lower Voc. In this fashion, benefits associated with higher substrate temperatures are seriously compromised. Concurrent with voiding is the observation that higher temperatures promote interdiffusion at the CdS/CdTe interface such that the effective thickness of the CdS layer is reduced. Variations in processing that correct for these detrimental effects have led to a total-area device efficiency of 12%.

  8. Electrochromic properties of nano-structured nickel oxide thin film prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Lin, Sheng-Hui; Chen, Fu-Rong; Kai, Ji-Jung

    2008-01-01

    In this study, we present a simple method to improve the electrochromic properties of a nickel oxide thin film. The method involves a three-step process—(a) conducting indium tin oxide (ITO) nano-particles were first sprayed onto a conducting substrate to form a porous nano-structured ITO layer, (b) nickel oxide film was then deposited onto the nano-structured ITO layer by a spray pyrolysis technique, and (c) the substrate, ITO nano-particles layer and nickel oxide film were annealed at high temperature of 300 °C to improve adhesion of these three layers. The microstructure of the resulting electrochromic cell was investigated using scanning electron microscopy. It is evident that the nickel oxide film covers the surface of the ITO nano-particle layer and forms a nano-structured nickel oxide (NSNO) film. The switching time and contrast were characterized by Autolab PGSTAT12 potentiostat and Jasco V-570 spectrophotometer. The results suggest that the transmittance contrast and switching time of NSNO are slightly superior to those of a conventional nickel oxide (CNO) film. However, the cycling durability of NSNO can be much better than that of CNO.

  9. Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

    SciTech Connect

    Mikhelashvili, V.; Padmanabhan, R.; Eisenstein, G.; Meyler, B.; Yofis, S.; Weindling, S.; Salzman, J.; Atiya, G.; Cohen-Hyams, Z.; Kaplan, W. D.; Ankonina, G.

    2015-10-07

    We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology.

  10. Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

    NASA Astrophysics Data System (ADS)

    Mikhelashvili, V.; Padmanabhan, R.; Meyler, B.; Yofis, S.; Atiya, G.; Cohen-Hyams, Z.; Weindling, S.; Ankonina, G.; Salzman, J.; Kaplan, W. D.; Eisenstein, G.

    2015-10-01

    We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology.

  11. Energy Efficient Electrochromic Windows Incorporating Ionic Liquids

    SciTech Connect

    Cheri Boykin; James Finley; Donald Anthony; Julianna Knowles; Richard Markovic; Michael Buchanan; Mary Ann Fuhry; Lisa Perrine

    2008-11-30

    One approach to increasing the energy efficiency of windows is to control the amount of solar radiation transmitted through a window by using electrochromic technology. What is unique about this project is that the electrochromic is based on the reduction/oxidation reactions of cathodic and anodic organic semi-conducting polymers using room temperature ionic liquids as ion transport electrolytes. It is believed that these types of coatings would be a lower cost alternative to traditional all inorganic thin film based electrochromic technologies. Although there are patents1 based on the proposed technology, it has never been reduced to practice and thoroughly evaluated (i.e. durability and performance) in a window application. We demonstrate that by using organic semi-conductive polymers, specific bands of the solar spectrum (specifically visible and near infrared) can be targeted for electrochemical variable transmittance responsiveness. In addition, when the technology is incorporated into an insulating glass unit, the energy parameters such as the solar heat gain coefficient and the light to solar gain ratio are improved over that of a typical insulating glass unit comprised of glass with a low emissivity coating. A minimum of {approx}0.02 quads of energy savings per year with a reduction of carbon emissions for electricity of {approx}320 MKg/yr benefit is achieved over that of a typical insulating glass unit including a double silver low-E coating. Note that these values include a penalty in the heating season. If this penalty is removed (i.e. in southern climates or commercial structures where cooling is predominate year-round) a maximum energy savings of {approx}0.05 quad per year and {approx}801 MKg/yr can be achieved over that of a typical insulating glass unit including a double silver low-E coating. In its current state, the technology is not durable enough for an exterior window application. The primary downfall is that the redox chemistry fails to

  12. Strongly improved electrochemical cycling durability by adding iridium to electrochromic nickel oxide films.

    PubMed

    Wen, Rui-Tao; Niklasson, Gunnar A; Granqvist, Claes G

    2015-05-13

    Anodically colored nickel oxide (NiO) thin films are of much interest as counter electrodes in tungsten oxide based electrochromic devices such as "smart windows" for energy-efficient buildings. However, NiO films are prone to suffering severe charge density degradation upon prolonged electrochemical cycling, which can lead to insufficient device lifetime. Therefore, a means to improve the durability of NiO-based films is an important challenge at present. Here we report that the incorporation of a modest amount of iridium into NiO films [Ir/(Ir + Ni) = 7.6 atom %] leads to remarkable durability, exceeding 10000 cycles in a lithium-conducting electrolyte, along with significantly improved optical modulation during extended cycling. Structure characterization showed that the face-centered-cubic-type NiO structure remained after iridium addition. Moreover, the crystallinity of these films was enhanced upon electrochemical cycling. PMID:25919917

  13. Polyaniline-based organic memristive device fabricated by layer-by-layer deposition technique

    NASA Astrophysics Data System (ADS)

    Erokhina, Svetlana; Sorokin, Vladimir; Erokhin, Victor

    2015-09-01

    Memristors and memristive devices represent a splendid area of research due to the unique possibilities for the realization of new types of computer hardware elements and mimicking several essential properties of the nervous system of living beings. The organic memristive device was developed as an electronic single-device analogue of the synapse, suitable for the realization of circuits allowing Hebbian type of learning. This work is dedicated to the realization of the active channel of organic memristive devices by polyelectrolyte self-assembling (layer-by-layer technique). Stable and reproducible electrical characteristics of the device were obtained when the thickness of the active channel was more than seven bilayers. The device revealed rectifying behaviour and the presence of hysteresis—important properties for the realization of neuromorphic systems with synapse-like properties of the individual elements. Compared to previously reported results on organic memristive devices fabricated using other methods, the present device does not require any additional doping that is usually performed through acid treatment. Such a behaviour is extremely important for the cases in which biological systems (nervous cells, slime mould, etc.) must be interfaced with the system of organic memristive devices, since acid treatment can kill living beings. [Figure not available: see fulltext.

  14. A Design Guide for Early-Market Electrochromic Windows

    SciTech Connect

    Lee, Eleanor S.; Selkowitz, Stephen E.; Clear, Robert D.; DiBartolomeo, Dennis L.; Klems, Joseph H.; Fernandes, Luis L.; Ward, GregJ.; Inkarojrit, Vorapat; Yazdanian, Mehry

    2006-05-01

    Switchable variable-tint electrochromic (EC) windows preserve view out while modulating transmitted light, glare, and solar heat gains. Consumers will require objective information on the risks and benefits of this emerging technology as it enters the market in 2006. This guide provides such information and data derived from a wide variety of simulations, laboratory tests, and a 2.5-year field test of prototype large-area EC windows evaluated under outdoor sun and sky conditions. This design guide is provided to architects, engineers, building owners, and others interested in electrochromic windows. The design guide provides basic information about what is an electrochromic window, what it looks like, how fast does it switch, and what current product offerings are. The guide also provides information on performance benefits if more mature product offerings were available.

  15. Inkjet catalyst printing and electroless copper deposition for low-cost patterned microwave passive devices on paper

    NASA Astrophysics Data System (ADS)

    Cook, Benjamin S.; Fang, Yunnan; Kim, Sangkil; Le, Taoran; Goodwin, W. Brandon; Sandhage, Kenneth H.; Tentzeris, Manos M.

    2013-09-01

    A scalable, low-cost process for fabricating copper-based microwave components on flexible, paper-based substrates is demonstrated. An inkjet printer is used to deposit a catalyst-bearing solution (tailored for such printing) in a desired pattern on commercially-available, recyclable, non-toxic (Teslin®) paper. The catalystbearing paper is then immersed in an aqueous copper-bearing solution to allow for electroless deposition of a compact and conformal layer of copper in the inkjet-derived pattern. Meander monopole antennas comprised of such electroless-deposited copper patterns on paper exhibited comparable performance as for antennas synthesized via inkjet printing of a commercially-available silver nanoparticle ink. However, the solution-based patterning and electroless copper deposition process avoids nozzle-clogging problems and costs associated with noble metal particle-based inks. This process yields compact conductive copper layers without appreciable oxidation and without the need for an elevated temperature, post-deposition thermal treatment commonly required for noble metal particle-based ink processes. This low-cost copper patterning process is readily scalable on virtually any substrate and may be used to generate a variety of copper-based microwave devices on flexible, paper-based substrates.

  16. Physical electrochemistry of nanostructured devices.

    PubMed

    Bisquert, Juan

    2008-01-01

    This Perspective reviews recent developments in experimental techniques and conceptual methods applied to the electrochemical properties of metal-oxide semiconductor nanostructures and organic conductors, such as those used in dye-sensitized solar cells, high-energy batteries, sensors, and electrochromic devices. The aim is to provide a broad view of the interpretation of electrochemical and optoelectrical measurements for semiconductor nanostructures (sintered colloidal particles, nanorods, arrays of quantum dots, etc.) deposited or grown on a conducting substrate. The Fermi level displacement by potentiostatic control causes a broad change of physical properties such as the hopping conductivity, that can be investigated over a very large variation of electron density. In contrast to traditional electrochemistry, we emphasize that in nanostructured devices we must deal with systems that depart heavily from the ideal, Maxwell-Boltzmann statistics, due to broad distributions of states (energy disorder) and interactions of charge carriers, therefore the electrochemical analysis must be aided by thermodynamics and statistical mechanics. We discuss in detail the most characteristic densities of states, the chemical capacitance, and the transport properties, specially the chemical diffusion coefficient, mobility, and generalized Einstein relation.

  17. Deposition of a-Si:H devices in a RTR system for photovoltaic and macroelectronic applications

    SciTech Connect

    Scholz, M.; Peros, D.; Boehm, M.

    1999-07-01

    This work presents first results of potential manufacturing processes for integrated series connected hydrogenated amorphous silicon (a-Si:H) thin film solar modules and/or pin-diode/TFT based macroelectronic circuits on flexible tapes. A RTR (Reel-To-Reel) deposition system on laboratory scale has been built. The system consists of seven metal sealed UHV stainless steel chambers to obtain ultra high vacuum as a basis for high quality a-Si:H layers. In order to support continuous movement of the tape in the RTR process the chambers cannot be isolated from each other. The necessary pressure difference between the sputtering chambers and the PECVD (Plasma Enhanced Chemical Vapor Deposition) chambers is provided by pressure stages. They are optimized for high molecular flow resistance without any influence on the moving substrate tape. The back metal contacts and the semitransparent TCO (Transparent Conductive Oxide) contacts are deposited by rf magnetron sputtering, the a-Si:H film system is deposited by PECVD. Parallel to the film deposition a Nd:YAG laser patterning system is coupled into one chamber. This allows for instance a total manufacturing of integrated series connected solar modules in one system without breaking the vacuum. The present investigations focus on the deposition of doped and intrinsic high quality a-Si:H based layers in neighboring chambers. The quality of semiconducting films deposited in adjacent chambers is studied with regard to potential contamination effects.

  18. Low-Temperature Ozone Exposure Technique to Modulate the Stoichiometry of WO(x) Nanorods and Optimize the Electrochromic Performance

    SciTech Connect

    Lin, F.; Li, C. P.; Chen, G.; Tenent, R. C.; Wolden, C. A.; Gillaspie, D. T.; Dillon, A. C.; Richards, R. M.; Engtrakul, C.

    2012-06-29

    A low-temperature ozone exposure technique was employed for the post-treatment of WO{sub x} nanorod thin films fabricated from hot-wire chemical vapor deposition (HWCVD) and ultrasonic spray deposition (USD) techniques. The resulting films were characterized with x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, UV-vis-NIR spectroscopy and x-ray photoelectron spectroscopy (XPS). The stoichiometry and surface crystallinity of the WO{sub x} thin films were subsequently modulated upon ozone exposure and thermal annealing without particle growth. The electrochromic performance was studied in a LiClO{sub 4}-propylene carbonate electrolyte, and the results suggest that the low-temperature ozone exposure technique is superior to the traditional high-temperature thermal annealing (employed to more fully oxidize the WO{sub x}). The optical modulation at 670 nm was improved from 35% for the as-deposited film to 57% for the film after ozone exposure at 150 C. The coloration efficiency was improved and the switching speed to the darkened state was significantly accelerated from 18.0 s for the as-deposited film to 11.8 s for the film after the ozone exposure. The process opens an avenue for low-temperature and cost-effective manufacturing of electrochromic films, especially on flexible polymer substrates.

  19. Optical properties of electrochromic vanadium pentoxide

    SciTech Connect

    Cogan, S. F.; Nguyen, N. M.; Perrotti, S. J.; Rauh, R. D.

    1989-08-01

    Electrochemical and spectroscopic measurements were used to characterize the electrochromic behavior of sputtered V/sub 2/O/sub 5/ films. In response to lithium intercalation, the fundamental optical absorption edge of V/sub 2/O/sub 5/ shifts to high energies by 0.20--0.31 eV as the lithium concentration increases from Li/sub 0.0/V/sub 2/O/sub 5/ to Li/sub 0.86/V/sub 2/O/sub 5/. There is a corresponding increase in the near-infrared absorption that exhibits Beer's law behavior at low lithium concentrations. The shift in absorption edge results in a large decrease in absorbance in the 350--450 nm wavelength range. This effect is most prevalent in thin films which exhibit a yellow to colorless optical modulation on lithium intercalation. The cathodic coloration in the near infrared is relatively weak with a maximum coloration efficiency of 35 cm/sup 2//C.

  20. An electrical conductivity based method of determining the particle deposition rate in air-liquid interface devices.

    PubMed

    Wiegand, Harald; Meyer, Jörg; Kasper, Gerhard

    2015-08-01

    A new in-situ method of determining the particle deposition rate onto cell cultures inside air-liquid interface devices is described. It is based on depositing a surrogate aerosol of salt particles onto the water filled wells of a culture plate while measuring the resulting change in electrical conductivity of the solution in situ, in order to derive the accumulated particle mass. For evaluation purposes, the wells of a six-well cell culture plate were equipped with custom designed electrodes and calibrated with a series of commercially available standard solutions. After the necessary corrections prescribed by theory, the calibration resulted in an accuracy and comparability between cells of ±3% in terms of measured conductivity. The method was then applied to a specific ALI device consisting essentially of the calibrated six-well culture plate inside an electrostatic cross-flow precipitator, and tested with submicron NaCl aerosol of defined size distribution produced by nebulization of a salt solution. 2h of particle accumulation were sufficient to accumulate between 30 and 10 μg of salt per well, depending on the location in the precipitator. Resulting deposition rates varied narrowly between the wells by about 2 ng min(-1) cm(-2). Factors affecting the overall accuracy and reproducibility are discussed.

  1. Fabrication of single TiO2 nanotube devices with Pt interconnections using electron- and ion-beam-assisted deposition

    NASA Astrophysics Data System (ADS)

    Lee, Mingun; Cha, Dongkyu; Huang, Jie; Ha, Min-Woo; Kim, Jiyoung

    2016-06-01

    Device fabrication using nanostructured materials, such as nanotubes, requires appropriate metal interconnections between nanotubes and electrical probing pads. Here, electron-beam-assisted deposition (EBAD) and ion-beam-assisted deposition (IBAD) techniques for fabrication of Pt interconnections for single TiO2 nanotube devices are investigated. IBAD conditions were optimized to reduce the leakage current as a result of Pt spreading. The resistivity of the IBAD-Pt was about three orders of magnitude less than that of the EBAD-Pt, due to low carbon concentration and Ga doping, as indicated by X-ray photoelectron spectroscopy analysis. The total resistances of single TiO2 nanotube devices with EBAD- or IBAD-Pt interconnections were 3.82 × 1010 and 4.76 × 108 Ω, respectively. When the resistivity of a single nanotube is low, the high series resistance of EBAD-Pt cannot be ignored. IBAD is a suitable method for nanotechnology applications, such as photocatalysis and biosensors.

  2. Effects of nasal drug delivery device and its orientation on sprayed particle deposition in a realistic human nasal cavity.

    PubMed

    Tong, Xuwen; Dong, Jingliang; Shang, Yidan; Inthavong, Kiao; Tu, Jiyuan

    2016-10-01

    In this study, the effects of nasal drug delivery device and the spray nozzle orientation on sprayed droplets deposition in a realistic human nasal cavity were numerically studied. Prior to performing the numerical investigation, an in-house designed automated actuation system representing mean adults actuation force was developed to produce realistic spray plume. Then, the spray plume development was filmed by high speed photography system, and spray characteristics such as spray cone angle, break-up length, and average droplet velocity were obtained through off-line image analysis. Continuing studies utilizing those experimental data as boundary conditions were applied in the following numerical spray simulations using a commercially available nasal spray device, which was inserted into a realistic adult nasal passage with external facial features. Through varying the particle releasing direction, the deposition fractions of selected particle sizes on the main nasal passage for targeted drug delivery were compared. The results demonstrated that the middle spray direction showed superior spray efficiency compared with upper or lower directions, and the 10µm agents were the most suitable particle size as the majority of sprayed agents can be delivered to the targeted area, the main passage. This study elaborates a comprehensive approach to better understand nasal spray mechanism and evaluate its performance for existing nasal delivery practices. Results of this study can assist the pharmaceutical industry to improve the current design of nasal drug delivery device and ultimately benefit more patients through optimized medications delivery. PMID:27509293

  3. Extraction of plasma from whole blood using a deposited microbead plug (DMBP) in a capillary-driven microfluidic device.

    PubMed

    Li, Chunyu; Liu, Chong; Xu, Zheng; Li, Jingmin

    2012-06-01

    We presented a deposited microbead plug (DMBP)-based microfluidic device capable of extracting plasma from whole blood by capillary forces. This device was fabricated by reversibly bonding a PDMS slab with a straight channel to a hydrophilic glass substrate. The DMBP was easily constructed at the inlet of the channel within 2 min by a method of natural deposition of microbeads without the need of weirs or photopolymerization. Capillary forces generated mainly on the hydrophilic glass substrate provided a driving force during the fabrication of the DMBP and plasma extraction, resulting in simplicity of operations. The DMBP only allows blood plasma to pass through but blocks blood cells, which was demonstrated experimentally using sheep blood. The DMBP enabled to remain in its initial configuration during plasma extraction. The high quality plasma was obtained without contamination of microbeads and blood cells. This easy-to-use, easy-to-integrate, disposable the DMBP-based microfluidic device has the potential to be integrated with on-chip bioanalytical units for the applications of point-of-care diagnostics.

  4. Effects of nasal drug delivery device and its orientation on sprayed particle deposition in a realistic human nasal cavity.

    PubMed

    Tong, Xuwen; Dong, Jingliang; Shang, Yidan; Inthavong, Kiao; Tu, Jiyuan

    2016-10-01

    In this study, the effects of nasal drug delivery device and the spray nozzle orientation on sprayed droplets deposition in a realistic human nasal cavity were numerically studied. Prior to performing the numerical investigation, an in-house designed automated actuation system representing mean adults actuation force was developed to produce realistic spray plume. Then, the spray plume development was filmed by high speed photography system, and spray characteristics such as spray cone angle, break-up length, and average droplet velocity were obtained through off-line image analysis. Continuing studies utilizing those experimental data as boundary conditions were applied in the following numerical spray simulations using a commercially available nasal spray device, which was inserted into a realistic adult nasal passage with external facial features. Through varying the particle releasing direction, the deposition fractions of selected particle sizes on the main nasal passage for targeted drug delivery were compared. The results demonstrated that the middle spray direction showed superior spray efficiency compared with upper or lower directions, and the 10µm agents were the most suitable particle size as the majority of sprayed agents can be delivered to the targeted area, the main passage. This study elaborates a comprehensive approach to better understand nasal spray mechanism and evaluate its performance for existing nasal delivery practices. Results of this study can assist the pharmaceutical industry to improve the current design of nasal drug delivery device and ultimately benefit more patients through optimized medications delivery.

  5. Electron cyclotron resonance deposition of amorphous silicon alloy films and devices

    SciTech Connect

    Shing, Y.H. )

    1992-10-01

    This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of solar cell performance. ECR growth parameters were systematically and extensively investigated; materials characterization included constant photocurrent measurement (CPM), junction capacitance, drive-level capacitance profiling (DLCP), optical transmission, light and dark photoconductivity, and small-angle X-ray scattering (SAXS). Conventional ECR-deposited a-Si:H was compared to a new form, a-Si:(Xe, H), in which xenon gas was added to the ECR plasma. a-Si:(Xe,H) possessed low, stable dark conductivities and high photosensitivites. Light-soaking revealed photodegradation rates about 35% lower than those of comparable radio frequency (rf)-deposited material. ECR-deposited p-type a SiC:H and intrinsic a-Si:H films underwent evaluation as components of p-i-n solar cells with standard rf films for the remaining layers.

  6. Influence of indium tin oxide electrodes deposited at room temperature on the properties of organic light-emitting devices

    SciTech Connect

    Satoh, Toshikazu; Fujikawa, Hisayoshi; Taga, Yasunori

    2005-10-03

    The influence of indium tin oxide (ITO) electrodes deposited at room temperature (ITO-RT) on the properties of organic light-emitting devices (OLEDs) has been studied. The OLED on the ITO-RT showed an obvious shorter lifetime and higher operating voltage than that on the conventional ITO electrode deposited at 573 K. The result of an in situ x-ray photoelectron spectroscopy analysis of the ITO electrode and the organic layer suggested that many of the hydroxyl groups that originate in the amorphous structure of the ITO-RT electrode oxidize the organic layer. The performance of the OLED on the ITO-RT is able to be explained by the oxidation of the organic layer.

  7. Electrochromic artificial muscles based on nanoporous metal-polymer composites

    NASA Astrophysics Data System (ADS)

    Detsi, E.; Onck, P. R.; De Hosson, J. T. M.

    2013-11-01

    This work shows that a nano-coating of electrochromic polymer grown onto the ligaments of nanoporous gold causes reversible dimensional and color changes during electrochemical actuation. This combination of electromechanical and optical properties opens additional avenues for the applications of artificial muscles, i.e., a metallic muscle exhibits its progress during work by changing color that can be detected by optical means.

  8. Electrophoretic Deposition for Cholesteric Liquid-Crystalline Devices with Memory and Modulation of Reflection Colors.

    PubMed

    Tokunaga, Shoichi; Itoh, Yoshimitsu; Yaguchi, Yuya; Tanaka, Hiroyuki; Araoka, Fumito; Takezoe, Hideo; Aida, Takuzo

    2016-06-01

    The first design strategy that allows both memorization and modulation of the liquid-crystalline reflection color is reported. Electrophoretic deposition of a tailored ionic chiral dopant is key to realizing this unprecedented function, which may pave the way for the development of full-color e-paper that can operate without the need of color filters. PMID:27027423

  9. Physical properties of ultrafast deposited micro- and nanothickness amorphous hydrogenated carbon films for medical devices and prostheses.

    PubMed

    Zaharia, T; Sullivan, I L; Saied, S O; Bosch, R C; Bijker, M D

    2007-02-01

    Hydrogenated amorphous carbon films with diamond-like structures have been formed on different substrates at very low energies and temperatures by a plasma-enhanced chemical vapour deposition (PECVD) process employing acetylene as the precursor gas. The plasma source was of a cascaded arc type with argon as the carrier gas. The films grown at very high deposition rates were found to have a practical thickness limit of approximately 1.5 microm, above which delamination from the substrate occurred. Deposition on silicon (100), glass, and plastic substrates has been studied and the films characterized in terms of sp3 content, roughness, hardness, adhesion, and optical properties. Deposition rates of up to 20 nm/s have been achieved at substrate temperatures below 100 degrees C. A typical sp3 content of 60-75 per cent in the films was determined by X-ray-generated Auger electron spectroscopy (XAES). The hardness, reduced modulus, and adhesion of the films were measured using a MicroMaterials NanoTest indenter/scratch tester. Hardness was found to vary from 4 to 13 GPa depending on the admixed acetylene flow and substrate temperature. The adhesion of the film to the substrate was significantly influenced by the substrate temperature and whether an in situ d.c. cleaning was employed prior to the deposition process. The hydrogen content in the film was measured by a combination of the Fourier transformation infrared (FTIR) spectroscopy and Rutherford backscattering (RBS) techniques. From the results it is concluded that the films formed by the process described here are ideal for the coating of long-term implantable medical devices, such as prostheses, stents, invasive probes, catheters, biosensors, etc. The properties reported in this publication are comparable with good-quality films deposited by other PECVD methods. The advantages of these films are the low ion energy and temperature of deposition, ensuring that no damage is done to sensitive substrates, very high

  10. Recovery Act: Electrochromic Glazing Technology: Improved Performance, Lower Price

    SciTech Connect

    Burdis, Mark; Sbar, Neil

    2012-06-30

    The growing dependency of the US on energy imports and anticipated further increases in energy prices reinforce the concerns about meeting the energy demand in the future and one element of a secure energy future is conservation. It is estimated that the buildings sector represents 40% of the US's total energy consumption. And buildings produce as much as one third of the greenhouse gas emissions primarily through fossil fuel usage during their operational phase. A significant fraction of this energy usage is simply due to inefficient window technology. Electrochromic (EC) windows allow electronic control of their optical properties so that the transparency to light can be adjusted from clear to dark. This ability to control the amount of solar energy allowed into the building can be advantageously used to minimize lighting, heating and air conditioning costs. Currently, the penetration of EC windows into the marketplace is extremely small, and consequently there is a huge opportunity for energy savings if this market can be expanded. In order to increase the potential energy savings it is necessary to increase the quantity of EC windows in operation. Additionally, any incremental improvement in the energy performance of each window will add to the potential energy savings. The overall goals of this project were therefore to improve the energy performance and lower the cost of dynamic (EC) smart windows for residential and commercial building applications. This project is obviously of benefit to the public by addressing two major areas: lowering the cost and improving the energy performance of EC glazings. The high level goals for these activities were: (i) to improve the range between the clear and the tinted state, (ii) reduce the price of EC windows by utilizing lower cost materials, (iii) lowering the U-Value1 SAGE Electrochromics Inc. is the only company in the US which has a track record of producing EC windows, and presently has a small operational factory

  11. Use of electrochromic materials in adaptive optics

    NASA Astrophysics Data System (ADS)

    Kammler, Daniel R.; Yelton, William G.; Sweatt, William C.; Verley, Jason C.

    2005-08-01

    Electrochromic (EC) materials are used in "smart" windows that can be darkened by applying a voltage across an EC stack on the window. The associated change in refractive index (n) in the EC materials might allow their use in tunable or temperature-insensitive Fabry-Perot filters and transmissive-spatial-light-modulators (SLMs). The authors are conducting a preliminary evaluation of these materials in many applications, including target-in-the-loop systems. Data on tungsten oxide, WO3, the workhorse EC material, indicate that it's possible to achieve modest changes in n with only slight increases in absorption between the visible and ~10 μm. This might enable construction of a tunable Fabry-Perot filter consisting of an active EC layer (e.g. WO3) and a proton conductor (e.g.Ta2O5) sandwiched between two gold electrodes. A SLM might be produced by replacing the gold with a transparent conductor (e.g. ITO). This SLM would allow broad-band operation like a micromirror array. Since it's a transmission element, simple optical designs like those in liquid-crystal systems would be possible. Our team has fabricated EC stacks and characterized their switching speed and optical properties (n, k). We plan to study the interplay between process parameters, film properties, and performance characteristics associated with the FP-filter and then extend what we learn to SLMs. Our goals are to understand whether the changes in absorption associated with changes in n are acceptable, and whether it's possible to design an EC-stack that's fast enough to be interesting. We'll present our preliminary findings regarding the potential viability of EC materials for target-in-the-loop applications.

  12. Use of electrochromic materials in adaptive optics.

    SciTech Connect

    Kammler, Daniel R.; Sweatt, William C.; Verley, Jason C.; Yelton, William Graham

    2005-07-01

    Electrochromic (EC) materials are used in 'smart' windows that can be darkened by applying a voltage across an EC stack on the window. The associated change in refractive index (n) in the EC materials might allow their use in tunable or temperature-insensitive Fabry-Perot filters and transmissive-spatial-light-modulators (SLMs). The authors are conducting a preliminary evaluation of these materials in many applications, including target-in-the-loop systems. Data on tungsten oxide, WO{sub 3}, the workhorse EC material, indicate that it's possible to achieve modest changes in n with only slight increases in absorption between the visible and {approx}10 {micro}m. This might enable construction of a tunable Fabry-Perot filter consisting of an active EC layer (e.g. WO{sub 3}) and a proton conductor (e.g.Ta{sub 2}O{sub 5}) sandwiched between two gold electrodes. A SLM might be produced by replacing the gold with a transparent conductor (e.g. ITO). This SLM would allow broad-band operation like a micromirror array. Since it's a transmission element, simple optical designs like those in liquid-crystal systems would be possible. Our team has fabricated EC stacks and characterized their switching speed and optical properties (n, k). We plan to study the interplay between process parameters, film properties, and performance characteristics associated with the FP-filter and then extend what we learn to SLMs. Our goals are to understand whether the changes in absorption associated with changes in n are acceptable, and whether it's possible to design an EC-stack that's fast enough to be interesting. We'll present our preliminary findings regarding the potential viability of EC materials for target-in-the-loop applications.

  13. Motion-driven electrochromic reactions for self-powered smart window system.

    PubMed

    Yeh, Min-Hsin; Lin, Long; Yang, Po-Kang; Wang, Zhong Lin

    2015-05-26

    The self-powered system is a promising concept for wireless networks due to its independent and sustainable operations without an external power source. To realize this idea, the triboelectric nanogenerator (TENG) was recently invented, which can effectively convert ambient mechanical energy into electricity to power up portable electronics. In this work, a self-powered smart window system was realized through integrating an electrochromic device (ECD) with a transparent TENG driven by blowing wind and raindrops. Driven by the sustainable output of the TENG, the optical properties, especially the transmittance of the ECD, display reversible variations due to electrochemical redox reactions. The maximum transmittance change at 695 nm can be reached up to 32.4%, which is comparable to that operated by a conventional electrochemical potentiostat (32.6%). This research is a substantial advancement toward the practical application of nanogenerators and self-powered systems.

  14. Motion-driven electrochromic reactions for self-powered smart window system.

    PubMed

    Yeh, Min-Hsin; Lin, Long; Yang, Po-Kang; Wang, Zhong Lin

    2015-05-26

    The self-powered system is a promising concept for wireless networks due to its independent and sustainable operations without an external power source. To realize this idea, the triboelectric nanogenerator (TENG) was recently invented, which can effectively convert ambient mechanical energy into electricity to power up portable electronics. In this work, a self-powered smart window system was realized through integrating an electrochromic device (ECD) with a transparent TENG driven by blowing wind and raindrops. Driven by the sustainable output of the TENG, the optical properties, especially the transmittance of the ECD, display reversible variations due to electrochemical redox reactions. The maximum transmittance change at 695 nm can be reached up to 32.4%, which is comparable to that operated by a conventional electrochemical potentiostat (32.6%). This research is a substantial advancement toward the practical application of nanogenerators and self-powered systems. PMID:25808880

  15. Flexible electrochromic supercapacitor hybrid electrodes based on tungsten oxide films and silver nanowires.

    PubMed

    Shen, Liuxue; Du, Lianhuan; Tan, Shaozao; Zang, Zhigang; Zhao, Chuanxi; Mai, Wenjie

    2016-05-01

    We successfully fabricate flexible electrochromic supercapacitor (SC) electrodes employing novel flexible transparent conducting substrates. The as-synthesized flexible electrochromic SC electrodes exhibit great electrochemical performances (13.6 mF cm(-2), 138.2 F g(-1)) and high coloration efficiency (80.2 cm(2) C(-1)), which demonstrate their potential applications in flexible smart windows combining energy storage and electrochromism. PMID:27087032

  16. Deposition of magnesium nitride thin films on stainless steel-304 substrates by using a plasma focus device

    NASA Astrophysics Data System (ADS)

    Ramezani, Amir Hoshang; Habibi, Maryam; Ghoranneviss, Mahmood

    2014-08-01

    In this research, for the first time, we synthesize magnesium nitride thin films on 304-type stainless steel substrates using a Mather-type (2 kJ) plasma focus (PF) device. The films of magnesium nitride are coated with different number of focus shots (like 15, 25 and 35) at a distance of 8 cm from the anode tip and at 0° angular position with respect to the anode axis. For investigation of the structural properties and surface morphology of magnesium nitride films, we utilized the X-ray diffractometer (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis, respectively. Also, the elemental composition is characterized by energy-dispersive X-ray (EDX) analysis. Furthermore, Vicker's microhardness is used to study the mechanical properties of the deposited films. The results show that the degree of crystallinity of deposited thin films (from XRD), the average size of particles and surface roughness (from AFM), crystalline growth of structures (from SEM) and the hardness values of the films depend on the number of focus shots. The EDX analysis demonstrates the existence of the elemental composition of magnesium in the deposited samples.

  17. Chemical vapor deposition and characterization of polysilanes polymer based thin films and their applications in compound semiconductors and silicon devices

    NASA Astrophysics Data System (ADS)

    Oulachgar, El Hassane

    As the semiconductors industry is moving toward nanodevices, there is growing need to develop new materials and thin films deposition processes which could enable strict control of the atomic composition and structure of thin film materials in order to achieve precise control on their electrical and optical properties. The accurate control of thin film characteristics will become increasingly important as the miniaturization of semiconductor devices continue. There is no doubt that chemical synthesis of new materials and their self assembly will play a major role in the design and fabrication of next generation semiconductor devices. The objective of this work is to investigate the chemical vapor deposition (CVD) process of thin film using a polymeric precursor as a source material. This process offers many advantages including low deposition cost, hazard free working environment, and most importantly the ability to customize the polymer source material through polymer synthesis and polymer functionalization. The combination between polymer synthesis and CVD process will enable the design of new generation of complex thin film materials with a wide range of improved chemical, mechanical, electrical and optical properties which cannot be easily achieved through conventional CVD processes based on gases and small molecule precursors. In this thesis we mainly focused on polysilanes polymers and more specifically poly(dimethylsilanes). The interest in these polymers is motivated by their distinctive electronic and photonic properties which are attributed to the delocalization of the sigma-electron along the Si-Si backbone chain. These characteristics make polysilane polymers very promising in a broad range of applications as a dielectric, a semiconductor and a conductor. The polymer-based CVD process could be eventually extended to other polymer source materials such as polygermanes, as well as and a variety of other inorganic and hybrid organic-inorganic polymers

  18. Vacuum deposited polymer films: Past, present, and future applications

    SciTech Connect

    Affinito, J.; Martin, P.; Gross, M.; Bennett, W.

    1994-11-01

    Two extremely high rate processes have been developed for the vacuum deposition of polymer thin films. Dubbed the PML (for Polymer Multi-Layer) and LML (for Liquid Multi-Layer) processes, the PML technique was originally developed for the manufacture of polymer/aluminum surface mount capacitors while the LML method arose from a need to fabricate lithium polymer batteries. These processes have since been found to be compatible with most other vacuum deposition techniques in, integrated, in-line coating processes. Battelle has developed an extensive program, and a great deal of hardware, to pursue a wide variety of PML and LML applications which integrate these two process technologies with other, conventional, vacuum deposition methods. The historical development of the technologies is reviewed and the Battelle PML/LML facilities are described. Current Battelle work involving solar thermal control films, PML QWOTs, and polymer/metal high reflectors are also discussed. Battelle PML work that is just starting, involving non-linear optical materials/devices, lithium polymer battery fabrication, electrochromic devices, and polymer/oxide multilayers, is discussed as well.

  19. Wafer scale interdigitated nanoelectrode devices functionalized using a MEMS-based deposition system

    NASA Astrophysics Data System (ADS)

    Martinez-Rivas, A.; Carcenac, F.; Saya, D.; Séverac, C.; Nicu, L.; Vieu, C.

    2012-03-01

    This paper reports on a methodology to elaborate interdigitated nanoelectrode devices (INDs) at the wafer scale, relying on a mix-and-match process which combines proximity optical lithography and electron beam lithography. An optimum exposure dose allowed fabricating nanodevices, at the wafer level, with a successful yield of 97%. The final devices are bonded onto conventional TO-8 packages. Electrical characterization in a short-circuited nanoelectrode is performed, revealing a 230 µΩ cm resistivity value at 23 °C. A MEMS-based spotter made of cantilevers (called Bioplume) has been used to obtain precise functionalization of the INDs with sub-picoliter volume solutions. These INDs are the basis of multiple tunnel junction nanodevices, intended to serve as novel highly sensitive nanobiosensors.

  20. Atmospheric pressure chemical vapor deposition of CdTe for high efficiency thin film PV devices: Annual subcontract report, 26 January 1999--25 January 2000

    SciTech Connect

    Meyers, P. V.; Kee, R.; Wolden, C.; Kestner, J.; Raja, L.; Kaydanov, V.; Ohno, T.; Collins, R.; Fahrenbruch, A.

    2000-05-30

    ITN's three year project Atmospheric Pressure Chemical Vapor Deposition (APCVD) of CdTe for High Efficiency Thin Film PV Devices has the overall objectives of improving thin film CdTe PV manufacturing technology and increasing CdTe PV device power conversion efficiency. CdTe deposition by APCVD employs the same reaction chemistry as has been used to deposit 16% efficient CdTe PV films, i.e., close spaced sublimation, but employs forced convection rather than diffusion as a mechanism of mass transport. Tasks of the APCVD program center on demonstration of APCVD of CdTe films, discovery of fundamental mass transport parameters, application of established engineering principles to the deposition of CdTe films, and verification of reactor design principles which could be used to design high throughput, high yield manufacturing equipment. Additional tasks relate to improved device measurement and characterization procedures that can lead to a more fundamental understanding of CdTe PV device operation and ultimately to higher device conversion efficiency and greater stability. Under the APCVD program, device analysis goes beyond conventional one-dimensional device characterization and analysis toward two dimension measurements and modeling. Accomplishments of the second year of the APCVD subcontract include: deposition of the first APCVD CdTe; identification of deficiencies in the first generation APCVD reactor; design, fabrication and testing of a ``simplified'' APCVD reactor; deposition of the first dense, adherent APCVD CdTe films; fabrication of the first APCVD CdTe PV device; modeling effects of CdSTe and SnOx layers; and electrical modeling of grain boundaries.

  1. Parametric optimization in virtual prototyping environment of the control device for a robotic system used in thin layers deposition

    NASA Astrophysics Data System (ADS)

    Enescu (Balaş, M. L.; Alexandru, C.

    2016-08-01

    The paper deals with the optimal design of the control system for a 6-DOF robot used in thin layers deposition. The optimization is based on parametric technique, by modelling the design objective as a numerical function, and then establishing the optimal values of the design variables so that to minimize the objective function. The robotic system is a mechatronic product, which integrates the mechanical device and the controlled operating device.The mechanical device of the robot was designed in the CAD (Computer Aided Design) software CATIA, the 3D-model being then transferred to the MBS (Multi-Body Systems) environment ADAMS/View. The control system was developed in the concurrent engineering concept, through the integration with the MBS mechanical model, by using the DFC (Design for Control) software solution EASY5. The necessary angular motions in the six joints of the robot, in order to obtain the imposed trajectory of the end-effector, have been established by performing the inverse kinematic analysis. The positioning error in each joint of the robot is used as design objective, the optimization goal being to minimize the root mean square during simulation, which is a measure of the magnitude of the positioning error varying quantity.

  2. Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display

    PubMed Central

    Tuukkanen, Sampo; Välimäki, Marja; Lehtimäki, Suvi; Vuorinen, Tiina; Lupo, Donald

    2016-01-01

    A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times. PMID:26957019

  3. Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display

    NASA Astrophysics Data System (ADS)

    Tuukkanen, Sampo; Välimäki, Marja; Lehtimäki, Suvi; Vuorinen, Tiina; Lupo, Donald

    2016-03-01

    A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times.

  4. Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display.

    PubMed

    Tuukkanen, Sampo; Välimäki, Marja; Lehtimäki, Suvi; Vuorinen, Tiina; Lupo, Donald

    2016-01-01

    A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times. PMID:26957019

  5. Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display.

    PubMed

    Tuukkanen, Sampo; Välimäki, Marja; Lehtimäki, Suvi; Vuorinen, Tiina; Lupo, Donald

    2016-03-09

    A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times.

  6. Sol-Gel Deposition of Iridium Oxide for Biomedical Micro-Devices

    PubMed Central

    Nguyen, Cuong M.; Rao, Smitha; Yang, Xuesong; Dubey, Souvik; Mays, Jeffrey; Cao, Hung; Chiao, Jung-Chih

    2015-01-01

    Flexible iridium oxide (IrOx)-based micro-electrodes were fabricated on flexible polyimide substrates using a sol-gel deposition process for utilization as integrated pseudo-reference electrodes for bio-electrochemical sensing applications. The fabrication method yields reliable miniature on-probe IrOx electrodes with long lifetime, high stability and repeatability. Such sensors can be used for long-term measurements. Various dimensions of sol-gel iridium oxide electrodes including 1 mm × 1 mm, 500 μm × 500 μm, and 100 μm × 100 μm were fabricated. Sensor longevity and pH dependence were investigated by immersing the electrodes in hydrochloric acid, fetal bovine serum (FBS), and sodium hydroxide solutions for 30 days. Less pH dependent responses, compared to IrOx electrodes fabricated by electrochemical deposition processes, were measured at 58.8 ± 0.4 mV/pH, 53.8 ± 1.3 mV/pH and 48 ± 0.6 mV/pH, respectively. The on-probe IrOx pseudo-reference electrodes were utilized for dopamine sensing. The baseline responses of the sensors were higher than the one using an external Ag/AgCl reference electrode. Using IrOx reference electrodes integrated on the same probe with working electrodes eliminated the use of cytotoxic Ag/AgCl reference electrode without loss in sensitivity. This enables employing such sensors in long-term recording of concentrations of neurotransmitters in central nervous systems of animals and humans. PMID:25686309

  7. Graphene-deposited microfiber photonic device for ultrahigh-repetition rate pulse generation in a fiber laser.

    PubMed

    Qi, You-Li; Liu, Hao; Cui, Hu; Huang, Yu-Qi; Ning, Qiu-Yi; Liu, Meng; Luo, Zhi-Chao; Luo, Ai-Ping; Xu, Wen-Cheng

    2015-07-13

    We report on the generation of a high-repetition-rate pulse in a fiber laser using a graphene-deposited microfiber photonic device (GMPD) and a Fabry-Perot filter. Taking advantage of the unique nonlinear optical properties of the GMPD, dissipative four-wave mixing effect (DFWM) could be induced at low pump power. Based on DFWM mode-locking mechanism, the fiber laser delivers a 100 GHz repetition rate pulse train. The results indicate that the small sized GMPD offers an alternative candidate of highly nonlinear optical component to achieve high-repetition rate pulses, and also opens up possibilities for the investigation of other abundant nonlinear effects or related fields of photonics. PMID:26191834

  8. Assembly of tungsten oxide nanobundles and their electrochromic properties

    NASA Astrophysics Data System (ADS)

    Chang, Xueting; Sun, Shibin; Li, Zhenjiang; Xu, Xiao; Qiu, Yanyan

    2011-04-01

    Lenticular W18O49 nanobundles composed of ultra-thin nanowires with diameters of 5-10 nm have been synthesized through a simple solvothermal method with hexachloride as precursor and mixed cyclohexanol and ethanol as solvent. Electrochromic films were prepared by assembling the W18O49 nanobundle suspension onto tin-doped indium oxide (ITO) coated glass. Results showed that self-assembly of the W18O49 nanobundles was strongly influenced by the solvents employed to disperse the nanobundles. The W18O49 nanobundles coated films exhibited excellent electrochromic stability and reversibility. The W18O49 nanobundle films also showed much higher charge-insertion density compared with the WO3 nanorod film, which may be due to the ultrathin feature of single nanowires constituting the nanobundles, unique oxygen vacancies of monoclinic W18O49, and the highly ordered assembly of the nanobundles.

  9. Highly effective antibiofilm coating of silver-polymer nanocomposite on polymeric medical devices deposited by one step plasma process.

    PubMed

    Agarwala, Munin; Barman, Tapan; Gogoi, Dolly; Choudhury, Bula; Pal, Arup R; Yadav, R N S

    2014-08-01

    Foley's catheters were coated with Silver (Ag), plasma polymerized aniline (PPAni) and Ag-PPAni composite by plasma based deposition processes which were characterized by XRD, EDX, SEM, and FT-IR spectroscopy and bioassays were performed to validate their efficacies to kill planktonic cells as well as to remove biofilm. The analyses confirmed the formation of Ag nanoparticles (AgNPs), PPAni and Ag-PPAni composite and also corroborated their successful deposition over the catheters. Antibacterial assays showed that coated catheters were capable of killing planktonic cells of most commonly encountered uropathogens and equally capable of eradicating biofilm formation by the uropathogens as evident from the reduced cfu/ml. UV-vis spectroscopy results showed that the nanoparticle coated catheters were capable of gradual release of AgNPs, killing all planktonic cells in solution over the time. Foley's catheters coated with AgNPs and their composites by one step plasma process were non-toxic devices capable of killing planktonic cells and proficient in eradicating biofilm formation which could be used to cutback the likelihood of the catheter related complications.

  10. Advances in silicon carbide Chemical Vapor Deposition (CVD) for semiconductor device fabrication

    NASA Technical Reports Server (NTRS)

    Powell, J. Anthony; Petit, Jeremy B.; Matus, Lawrence G.

    1991-01-01

    Improved SiC chemical vapor deposition films of both 3C and 6H polytypes were grown on vicinal (0001) 6H-SiC wafers cut from single-crystal boules. These films were produced from silane and propane in hydrogen at one atmosphere at a temperature of 1725 K. Among the more important factors which affected the structure and morphology of the grown films were the tilt angle of the substrate, the polarity of the growth surface, and the pregrowth surface treatment of the substrate. With proper pregrowth surface treatment, 6H films were grown on 6H substrates with tilt angles as small as 0.1 degrees. In addition, 3C could be induced to grow within selected regions on a 6H substrate. The polarity of the substrate was a large factor in the incorporation of dopants during epitaxial growth. A new growth model is discussed which explains the control of SiC polytype in epitaxial growth on vicinal (0001) SiC substrates.

  11. Focused R&D For Electrochromic Smart Windowsa: Significant Performance and Yield Enhancements

    SciTech Connect

    Mark Burdis; Neil Sbar

    2003-01-31

    There is a need to improve the energy efficiency of building envelopes as they are the primary factor governing the heating, cooling, lighting and ventilation requirements of buildings--influencing 53% of building energy use. In particular, windows contribute significantly to the overall energy performance of building envelopes, thus there is a need to develop advanced energy efficient window and glazing systems. Electrochromic (EC) windows represent the next generation of advanced glazing technology that will (1) reduce the energy consumed in buildings, (2) improve the overall comfort of the building occupants, and (3) improve the thermal performance of the building envelope. ''Switchable'' EC windows provide, on demand, dynamic control of visible light, solar heat gain, and glare without blocking the view. As exterior light levels change, the window's performance can be electronically adjusted to suit conditions. A schematic illustrating how SageGlass{reg_sign} electrochromic windows work is shown in Figure I.1. SageGlass{reg_sign} EC glazings offer the potential to save cooling and lighting costs, with the added benefit of improving thermal and visual comfort. Control over solar heat gain will also result in the use of smaller HVAC equipment. If a step change in the energy efficiency and performance of buildings is to be achieved, there is a clear need to bring EC technology to the marketplace. This project addresses accelerating the widespread introduction of EC windows in buildings and thus maximizing total energy savings in the U.S. and worldwide. We report on R&D activities to improve the optical performance needed to broadly penetrate the full range of architectural markets. Also, processing enhancements have been implemented to reduce manufacturing costs. Finally, tests are being conducted to demonstrate the durability of the EC device and the dual pane insulating glass unit (IGU) to be at least equal to that of conventional windows.

  12. ZnO/Al:ZnO Transparent Resistive Switching Devices Grown by Atomic Layer Deposition for Memristor Applications.

    PubMed

    Mundle, Rajeh; Carvajal, Christian; Pradhan, Aswini K

    2016-05-17

    ZnO has intrinsic semiconductor conductivity because of an unintentional doping mechanism resulting from the growth process that is mainly attributable to oxygen vacancies (VO) positioned in the bandgap. ZnO has multiple electronic states that depend on the number of vacancies and the charge state of each vacancy. In addition to the individual electron states, the vacancies have different vibrational states. We developed a high-temperature precursor vapor mask technique using Al2O3 to pattern the atomic layer deposition of ZnO and Al:ZnO layers on ZnO-based substrates. This technique was used to create a memristor device based on Al:ZnO thin films having metallic and semiconducting and insulating transport properties ZnO. We demonstrated that adding combination of Al2O3 and TiO2 barrier layers improved the resistive switching behavior. The change in the resistance between the high- and low-resistivity states of the memristor with a combination of Al2O3 and TiO2 was approximately 157%. The devices were exposed to laser light from three different laser diodes. The 450 nm laser diode noticeably affected the combined Al2O3 and TiO2 barrier, creating a high-resistivity state with a 2.9% shift under illumination. The high-resistivity state shift under laser illumination indicates defect shifts and the thermodynamic transition of ZnO defects. PMID:27124366

  13. Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

    SciTech Connect

    Bolat, Sami Tekcan, Burak; Ozgit-Akgun, Cagla; Biyikli, Necmi; Okyay, Ali Kemal

    2015-01-15

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N{sub 2}/H{sub 2} PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH{sub 3} PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N{sub 2}:H{sub 2} ambient.

  14. ZnO/Al:ZnO Transparent Resistive Switching Devices Grown by Atomic Layer Deposition for Memristor Applications.

    PubMed

    Mundle, Rajeh; Carvajal, Christian; Pradhan, Aswini K

    2016-05-17

    ZnO has intrinsic semiconductor conductivity because of an unintentional doping mechanism resulting from the growth process that is mainly attributable to oxygen vacancies (VO) positioned in the bandgap. ZnO has multiple electronic states that depend on the number of vacancies and the charge state of each vacancy. In addition to the individual electron states, the vacancies have different vibrational states. We developed a high-temperature precursor vapor mask technique using Al2O3 to pattern the atomic layer deposition of ZnO and Al:ZnO layers on ZnO-based substrates. This technique was used to create a memristor device based on Al:ZnO thin films having metallic and semiconducting and insulating transport properties ZnO. We demonstrated that adding combination of Al2O3 and TiO2 barrier layers improved the resistive switching behavior. The change in the resistance between the high- and low-resistivity states of the memristor with a combination of Al2O3 and TiO2 was approximately 157%. The devices were exposed to laser light from three different laser diodes. The 450 nm laser diode noticeably affected the combined Al2O3 and TiO2 barrier, creating a high-resistivity state with a 2.9% shift under illumination. The high-resistivity state shift under laser illumination indicates defect shifts and the thermodynamic transition of ZnO defects.

  15. High-Purity Isolation and Recovery of Circulating Tumor Cells using Conducting Polymer-deposited Microfluidic Device

    PubMed Central

    Jeon, SeungHyun; Hong, WooYoung; Lee, Eun Sook; Cho, Youngnam

    2014-01-01

    We have developed a conductive nano-roughened microfluidic device and demonstrated its use as an electrically modulated capture and release system for studying rare circulating tumor cells (CTCs). The microchannel surfaces were covalently decorated with epithelial cancer-specific anti-EpCAM antibody by electrochemical deposition of biotin-doped polypyrrole (Ppy), followed by the assembly of streptavidin and biotinylated antibody. Our method utilizes the unique topographical features and excellent electrical activity of Ppy for i) surface-induced preferential recognition and release of CTCs, and ii) selective elimination of non-specifically immobilized white blood cells (WBCs), which are capable of high-purity isolation of CTCs. In addition, the direct incorporation of biotin molecules offers good flexibility, because it allows the modification of channel surfaces with diverse antibodies, in addition to anti-EpCAM, for enhanced detection of multiple types of CTCs. By engineering a series of electrical, chemical, and topographical cues, this simple yet efficient device provides a significant advantage to CTC detection technology as compared with other conventional methods. PMID:25250093

  16. The growth and characterization of group III-nitride transistor devices grown by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Wong, Michael Ming

    The InAlGaN, or III-nitride, material system has received much interest from the research community. A direct wide bandgap semiconductor, GaN offers a high breakdown field (>3 x 106 V/cm) due to its large bandgap energy of 3.4 eV, high electron saturation velocity (1.5 x 10 7 cm/s, predicted peak up to 2.7 x 107 cm/s), good thermal conductivity (≥1.7 W/cm K), and reasonable mobility (800 cm 2/V s). In an AlGaN/GaN heterostructure, the formation of a two-dimensional electron gas (2DEG) leads to a higher electron mobility (2000 cm2/V s) and a high sheet density (1--5 x 1013 cm -2). This makes transistors based on the III-nitride material system ideal for high-temperature, high-power, and high-frequency applications. Two such transistors include the heterojunction field-effect transistor (HFET) and bipolar junction transistor (BJT), which includes the heterojunction bipolar transistor (HBT). Both HFETs and HBTs were studied, and the epitaxial heterostructures were grown by the metalorganic chemical vapor deposition (MOCVD) technique. The MOCVD process and system are described, along with the growth details. As material characterization is important for the optimization of growth, several of the techniques used are discussed. An extensive study to improve the performance of AlGaN/GaN HFETs is detailed. Through the use of a delta-doped, binary barrier novel device structure, the highest reported maximum drain current and transconductance is reported: IDSmax = 1.82 A/mm and gm = 331 mS/mm. The device also exhibits excellent RF characteristics. HBTs based on the III-nitride material system face a more difficult challenge associated with p-type material. Development of HBTs is still in the early stages, although there are reports of working devices. The gain is still below its potential, but many of the issues have been identified. Two novel structures are reported for the first time, a GaN/InGaN/GaN pnp HBT and a AlGaN/GaN npn graded-base and collector-up HBT. The

  17. Degradation of electrochromic film of amorphous tungsten oxide after coloration

    NASA Astrophysics Data System (ADS)

    Luo, Zhongkuan

    1992-11-01

    The degradation of the electrochromic film of a-WO3 was investigated from the equilibrium state of different driving voltage and the time dependent emf was also obtained in an open or short circuit of zero volts. Based on the mechanism of activation and the principal of chemical reaction kinetics, the correct definition of electrochromic memory was made and a relation of memory was obtained. It was also found that at the initial time of natural bleaching, the change rate of proton concentration in the film was also obtained. According to the mechanism of electrochromic memory, it was indicated that in the open circuit case, the theoretical reaction of the change rate of electric potential was in good agrement with the experimental results, and furthermore, the reaction constant was determined with the experimental data. In the short circuit case, there exist two effects on degradation, the short circuit current caused by the backward emf, and the oxidation of the colored film. The experimental data shows that, in the short circuit case, the degradation strongly depends on the short circuit current and the effect of chemical reaction can be neglected.

  18. High Growth Rate Deposition of Hydrogenated Amorphous Silicon-Germanium Films and Devices Using ECR-PECVD

    SciTech Connect

    Yong Liu

    2002-05-31

    Hydrogenated amorphous silicon germanium films (a-SiGe:H) and devices have been extensively studied because of the tunable band gap for matching the solar spectrum and mature the fabrication techniques. a-SiGe:H thin film solar cells have great potential for commercial manufacture because of very low cost and adaptability to large-scale manufacturing. Although it has been demonstrated that a-SiGe:H thin films and devices with good quality can be produced successfully, some issues regarding growth chemistry have remained yet unexplored, such as the hydrogen and inert-gas dilution, bombardment effect, and chemical annealing, to name a few. The alloying of the SiGe introduces above an order-of-magnitude higher defect density, which degrades the performance of the a-SiGe:H thin film solar cells. This degradation becomes worse when high growth-rate deposition is required. Preferential attachment of hydrogen to silicon, clustering of Ge and Si, and columnar structure and buried dihydride radicals make the film intolerably bad. The work presented here uses the Electron-Cyclotron-Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR-PECVD) technique to fabricate a-SiGe:H films and devices with high growth rates. Helium gas, together with a small amount of H{sub 2}, was used as the plasma species. Thickness, optical band gap, conductivity, Urbach energy, mobility-lifetime product, I-V curve, and quantum efficiency were characterized during the process of pursuing good materials. The microstructure of the a-(Si,Ge):H material was probed by Fourier-Transform Infrared spectroscopy. They found that the advantages of using helium as the main plasma species are: (1) high growth rate--the energetic helium ions break the reactive gas more efficiently than hydrogen ions; (2) homogeneous growth--heavy helium ions impinging on the surface promote the surface mobility of the reactive radicals, so that heteroepitaxy growth as clustering of Ge and Si, columnar structure are reduced

  19. Design and construction of experimental device to study cryogen droplet deposition and heat transfer

    NASA Astrophysics Data System (ADS)

    Keller, Matthew; Aguilar, Guillermo; Nelson, J. Stuart

    2003-06-01

    Cryogen spray cooling (CSC) is used to pre-cool the epidermis during laser dermatological procedures such as treatment of port wine stain (PWS) birthmarks. It is known that PWS patients with medium to high epidermal melanin concentrations are at a high risk of epidermal thermal damage after laser irradiation. To avoid this complication, it is necessary to maximize CSC efficiency and, thus, essential to understand the mechanical and thermal interactions of cryogen droplets with the sprayed surface. It has been observed that cryogen sprays exhibit droplet rebound as droplets impinge on the skin surface. Studies of water droplet impact on hard surfaces have shown that droplet rebound may be suppressed by dissolving small amounts (a few percent) of diverse polymer or surfactant solutions prior to atomization. To investigate the possibility of suppressing the rebound of cryogen droplets in a similar way, we have constructed a device that allows observation of the impact, spreading, and rebound of individual water and cryogen droplets with and without these solutions, and their influence on cryogen/surface dynamics and heat transfer. Our preliminary studies show that dissolving a 4% non-ionic surfactant in water reduces droplet rebound and thickness of the residual liquid layer. The maximum spread of water droplets after impact can be described within 20% accuracy by a previously developed theoretical model. The same model provides an even more accurate prediction of the maximum spread of cryogen droplets. This study will aid the analysis of future results and design conditions of new studies, which will recreate conditions to determine if added surfactant solutions suppress droplet rebound and lead to improved CSC efficiency.

  20. Resistive switching in the Au/Zr/ZrO2-Y2O3/TiN/Ti memristive devices deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Gorshkov, O. N.; Mikhaylov, A. N.; Kasatkin, A. P.; Tikhov, S. V.; Filatov, D. O.; Pavlov, D. A.; Belov, A. I.; Koryazhkina, M. N.; Bobrov, A. I.; Malekhonova, N. V.; Gryaznov, E. G.; Antonov, I. N.; Shenina, M. E.

    2016-08-01

    Bipolar resistive switching phenomenon in the Au/Zr/ZrO2-Y2O3/TiN/Ti memristive devices deposited by magnetron sputtering has been studied. The structure of devices and electrical measurements data for the temperature range from 77 to 490 K are analyzed. The stable switching is demonstrated at room temperature, but the decrease in the resistive switching performance at elevated temperatures is observed.

  1. Durable Electrooptic Devices Comprising Ionic Liquids

    SciTech Connect

    Burrell, Anthony K.; Agrawal, Anoop; Cronin, John P.; Tonazzi, Juan C. L.; Warner, Benjamin P.; McCleskey, T. Mark

    2008-11-11

    Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes. Some of the electrolyte solutions color to red when devices employing the solutions are powered, leading to red or neutral electrooptic devices.

  2. Durable electrooptic devices comprising ionic liquids

    DOEpatents

    Burrell, Anthony K.; Agrawal, Anoop; Cronin; John P.; Tonazzi, Juan C. L.; Warner, Benjamin P.; McCleskey, T. Mark

    2009-12-15

    Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes. Some of the electrolyte solutions color to red when devices employing the solutions are powered, leading to red or neutral electrooptic devices.

  3. Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition

    PubMed Central

    Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

    2016-01-01

    With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption. PMID:27312225

  4. Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition.

    PubMed

    Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

    2016-01-01

    With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption. PMID:27312225

  5. Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

    2016-06-01

    With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption.

  6. Comparative study of electrochromic enhancement of latent fingerprints with existing development techniques.

    PubMed

    Beresford, Ann L; Brown, Rachel M; Hillman, A Robert; Bond, John W

    2012-01-01

    To address the challenge of capturing latent fingerprint evidence from metal surfaces, a new method of latent fingerprint enhancement based on electrochromic polymer films has recently been developed. Here, we present a study comparing the development and visualization of nonvisible fingerprints on stainless steel substrates using this electrochromic enhancement approach with three classical methods (dusting, wet powder, and cyanoacrylate fuming). Two variants of the electrochromic enhancement method were utilized with polyaniline and poly(3,4-ethylenedioxythiophene) as the electrochromic materials. Fingerprint samples were taken from different donors (varying in age and gender) and were exposed to different environments for systematically varied periods of time (up to 28 days). The environments represent plausible evidential scenarios: left under ambient conditions, washed with aqueous soap solution, washed with acetone, submerged in water, and maintained at elevated temperature. The electrochromic enhancement procedure frequently outperformed the traditional methods, particularly for samples exposed to more challenging histories.

  7. Laser-induced evaporation, reactivity and deposition of ZrO 2, CeO 2, V 2O 5 and mixed Ce-V oxides

    NASA Astrophysics Data System (ADS)

    Flamini, C.; Ciccioli, A.; Traverso, P.; Gnecco, F.; Giardini Guidoni, A.; Mele, A.

    2000-12-01

    It has been found that pulsed laser ablation has good potentiality for the deposition of ZrO2, CeO2, V2O5 and mixed Ce-V oxides which are very important materials for their application in optics and electrochromic devices. Laser induced compositional changes of thin films in the ablation and deposition processes of these materials have been explored. The effect of the oxygen gas pressure on the thin film composition has been examined. The congruency of the process has been treated on the basis of a thermal mechanism of evaporation-decomposition of the compounds. An attempt to model the processes by means of a thermodynamic approach is reported.

  8. One material, multiple functions: graphene/Ni(OH)2 thin films applied in batteries, electrochromism and sensors

    PubMed Central

    Neiva, Eduardo G. C.; Oliveira, Marcela M.; Bergamini, Márcio F.; Marcolino, Luiz H.; Zarbin, Aldo J. G.

    2016-01-01

    Different nanocomposites between reduced graphene oxide (rGO) and Ni(OH)2 nanoparticles were synthesized through modifications in the polyol method (starting from graphene oxide (GO) dispersion in ethylene glycol and nickel acetate), processed as thin films through the liquid-liquid interfacial route, homogeneously deposited over transparent electrodes and spectroscopically, microscopically and electrochemically characterized. The thin and transparent nanocomposite films (112 to 513 nm thickness, 62.6 to 19.9% transmittance at 550 nm) consist of α-Ni(OH)2 nanoparticles (mean diameter of 4.9 nm) homogeneously decorating the rGO sheets. As a control sample, neat Ni(OH)2 was prepared in the same way, consisting of porous nanoparticles with diameter ranging from 30 to 80 nm. The nanocomposite thin films present multifunctionality and they were applied as electrodes to alkaline batteries, as electrochromic material and as active component to electrochemical sensor to glycerol. In all the cases the nanocomposite films presented better performances when compared to the neat Ni(OH)2 nanoparticles, showing energy and power of 43.7 W h kg−1 and 4.8 kW kg−1 (8.24 A g−1) respectively, electrochromic efficiency reaching 70 cm2 C−1 and limit of detection as low as 15.4 ± 1.2 μmol L−1. PMID:27654065

  9. One material, multiple functions: graphene/Ni(OH)2 thin films applied in batteries, electrochromism and sensors

    NASA Astrophysics Data System (ADS)

    Neiva, Eduardo G. C.; Oliveira, Marcela M.; Bergamini, Márcio F.; Marcolino, Luiz H.; Zarbin, Aldo J. G.

    2016-09-01

    Different nanocomposites between reduced graphene oxide (rGO) and Ni(OH)2 nanoparticles were synthesized through modifications in the polyol method (starting from graphene oxide (GO) dispersion in ethylene glycol and nickel acetate), processed as thin films through the liquid-liquid interfacial route, homogeneously deposited over transparent electrodes and spectroscopically, microscopically and electrochemically characterized. The thin and transparent nanocomposite films (112 to 513 nm thickness, 62.6 to 19.9% transmittance at 550 nm) consist of α-Ni(OH)2 nanoparticles (mean diameter of 4.9 nm) homogeneously decorating the rGO sheets. As a control sample, neat Ni(OH)2 was prepared in the same way, consisting of porous nanoparticles with diameter ranging from 30 to 80 nm. The nanocomposite thin films present multifunctionality and they were applied as electrodes to alkaline batteries, as electrochromic material and as active component to electrochemical sensor to glycerol. In all the cases the nanocomposite films presented better performances when compared to the neat Ni(OH)2 nanoparticles, showing energy and power of 43.7 W h kg‑1 and 4.8 kW kg‑1 (8.24 A g‑1) respectively, electrochromic efficiency reaching 70 cm2 C‑1 and limit of detection as low as 15.4 ± 1.2 μmol L‑1.

  10. In situ deposition of a personalized nanofibrous dressing via a handy electrospinning device for skin wound care

    NASA Astrophysics Data System (ADS)

    Dong, Rui-Hua; Jia, Yue-Xiao; Qin, Chong-Chong; Zhan, Lu; Yan, Xu; Cui, Lin; Zhou, Yu; Jiang, Xingyu; Long, Yun-Ze

    2016-02-01

    Current strategies for wound care provide limited relief to millions of patients who suffer from burns, chronic skin ulcers or surgical-related wounds. The goal of this work is to develop an in situ deposition of a personalized nanofibrous dressing via a handy electrospinning (e-spinning) device and evaluate its properties related to skin wound care. MCM-41 type mesoporous silica nanoparticles decorated with silver nanoparticles (Ag-MSNs) were prepared by a facile and environmentally friendly approach, which possessed long-term antibacterial activity and low cytotoxicity. Poly-ε-caprolactone (PCL) incorporated with Ag-MSNs was successfully electrospun (e-spun) into nanofibrous membranes. These in situ e-spun nanofibrous membranes allowed the continuous release of Ag ions and showed broad-spectrum antimicrobial activity against two common types of pathogens, Staphylococcus aureus and Escherichia coli. In addition, the in vivo studies revealed that these antibacterial nanofibrous membranes could reduce the inflammatory response and accelerate wound healing in Wistar rats. The above results strongly demonstrate that such patient-specific dressings could be broadly applied in emergency medical transport, hospitals, clinics and at the patients' home in the near future.Current strategies for wound care provide limited relief to millions of patients who suffer from burns, chronic skin ulcers or surgical-related wounds. The goal of this work is to develop an in situ deposition of a personalized nanofibrous dressing via a handy electrospinning (e-spinning) device and evaluate its properties related to skin wound care. MCM-41 type mesoporous silica nanoparticles decorated with silver nanoparticles (Ag-MSNs) were prepared by a facile and environmentally friendly approach, which possessed long-term antibacterial activity and low cytotoxicity. Poly-ε-caprolactone (PCL) incorporated with Ag-MSNs was successfully electrospun (e-spun) into nanofibrous membranes. These in situ e

  11. In-situ deposition and processing of YBa2Cu3O(7-x) films and multilayers for optoelectronic devices

    NASA Astrophysics Data System (ADS)

    Villegier, J. C.; Moriceau, H.; Boucher, H.; di Cioccio, L.; Chicault, R.

    1991-03-01

    In situ direct deposition at about 700 C of thin YBa2Cu3O(7-x) superconductive films and multilayers has been done by three techniques using stoichiometric YBa2Cu3O(7-x) sintered targets. Excimer laser ablation in a dc magnetron system with hollow and planar targets leads to 0.5-, 1.2-, and 2.5-in diameter uniformly superconductive layers under static conditions. High critical current densities associated with low resistivity and good epitaxial behavior are achieved on top of MgO, SrTiO3, LaAlO3, and YSZ single-crystal wafers. High-quality c-oriented films are routinely obtained by means of a dc magnetron on large sapphire substrates covered by a YSZ RF sputtered buffer layer. The infrared properties of such films have been checked at 1.15-micron wavelength. In order to achieve active devices, small YBa2Cu3O7-YSZ-Ag tunnel junctions and arrays have been successfully patterned in the superconductor/insulator/normal-metal trilayers using SNOP (selective niobium overlap process).

  12. Electrochromic windows for commercial buildings: Monitored results from a full-scale testbed

    SciTech Connect

    Lee, Eleanor S.; DiBartolomeo, Dennis L.; Selkowitz, Stephen E.

    2000-04-01

    Electrochromic glazings promise to be the next major advance in energy-efficient window technology, helping to transform windows and skylights from an energy liability to an energy source for the nation's building stock. Monitored results from a full-scale demonstration of large-area electrochromic windows are given. The test consisted of two side-by-side, 3.7x4.6-m, office-like rooms. In each room, five 62x173-cm lower electrochromic windows and five 62x43-cm upper electrochromic windows formed a large window wall. The window-to-exterior-wall ratio (WWR) was 0.40. The southeast-facing electrochromic windows had an overall visible transmittance (Tv) range of Tv=0.11-0.38 and were integrated with a dimmable electric lighting system to provide constant work plane illuminance and to control direct sun. Daily lighting use from the automated electrochromic window system decreased by 6 to 24% compared to energy use with static, low-transmission (Tv =0.11), unshaded windows in overcast to cle ar sky winter conditions in Oakland, California. Daily lighting energy use increased as much as 13% compared to lighting energy use with static windows that had Tv=0.38. Even when lighting energy savings were not obtainable, the visual environment produced by the electrochromic windows, indicated by well-controlled window and room luminance levels, was significantly improved for computer-type tasks throughout the day compared to the visual environment with unshaded 38%-glazing. Cooling loads were not measured, but previous building energy simulations indicate that additional savings could be achieved. To ensure visual and thermal comfort, electrochromics require occasional use of interior or exterior shading systems when direct sun is present. Other recommendations to improve electrochromic materials and controls are noted along with some architectural constraints.

  13. Large elasto-optic effect and reversible electrochromism in multiferroic BiFeO3

    PubMed Central

    Sando, D.; Yang, Yurong; Bousquet, E.; Carrétéro, C.; Garcia, V.; Fusil, S.; Dolfi, D.; Barthélémy, A.; Ghosez, Ph.; Bellaiche, L.; Bibes, M.

    2016-01-01

    The control of optical fields is usually achieved through the electro-optic or acousto-optic effect in single-crystal ferroelectric or polar compounds such as LiNbO3 or quartz. In recent years, tremendous progress has been made in ferroelectric oxide thin film technology—a field which is now a strong driving force in areas such as electronics, spintronics and photovoltaics. Here, we apply epitaxial strain engineering to tune the optical response of BiFeO3 thin films, and find a very large variation of the optical index with strain, corresponding to an effective elasto-optic coefficient larger than that of quartz. We observe a concomitant strain-driven variation in light absorption—reminiscent of piezochromism—which we show can be manipulated by an electric field. This constitutes an electrochromic effect that is reversible, remanent and not driven by defects. These findings broaden the potential of multiferroics towards photonics and thin film acousto-optic devices, and suggest exciting device opportunities arising from the coupling of ferroic, piezoelectric and optical responses. PMID:26923332

  14. Large elasto-optic effect and reversible electrochromism in multiferroic BiFeO3

    NASA Astrophysics Data System (ADS)

    Sando, D.; Yang, Yurong; Bousquet, E.; Carrétéro, C.; Garcia, V.; Fusil, S.; Dolfi, D.; Barthélémy, A.; Ghosez, Ph.; Bellaiche, L.; Bibes, M.

    2016-02-01

    The control of optical fields is usually achieved through the electro-optic or acousto-optic effect in single-crystal ferroelectric or polar compounds such as LiNbO3 or quartz. In recent years, tremendous progress has been made in ferroelectric oxide thin film technology--a field which is now a strong driving force in areas such as electronics, spintronics and photovoltaics. Here, we apply epitaxial strain engineering to tune the optical response of BiFeO3 thin films, and find a very large variation of the optical index with strain, corresponding to an effective elasto-optic coefficient larger than that of quartz. We observe a concomitant strain-driven variation in light absorption--reminiscent of piezochromism--which we show can be manipulated by an electric field. This constitutes an electrochromic effect that is reversible, remanent and not driven by defects. These findings broaden the potential of multiferroics towards photonics and thin film acousto-optic devices, and suggest exciting device opportunities arising from the coupling of ferroic, piezoelectric and optical responses.

  15. Large elasto-optic effect and reversible electrochromism in multiferroic BiFeO3.

    PubMed

    Sando, D; Yang, Yurong; Bousquet, E; Carrétéro, C; Garcia, V; Fusil, S; Dolfi, D; Barthélémy, A; Ghosez, Ph; Bellaiche, L; Bibes, M

    2016-01-01

    The control of optical fields is usually achieved through the electro-optic or acousto-optic effect in single-crystal ferroelectric or polar compounds such as LiNbO3 or quartz. In recent years, tremendous progress has been made in ferroelectric oxide thin film technology-a field which is now a strong driving force in areas such as electronics, spintronics and photovoltaics. Here, we apply epitaxial strain engineering to tune the optical response of BiFeO3 thin films, and find a very large variation of the optical index with strain, corresponding to an effective elasto-optic coefficient larger than that of quartz. We observe a concomitant strain-driven variation in light absorption--reminiscent of piezochromism--which we show can be manipulated by an electric field. This constitutes an electrochromic effect that is reversible, remanent and not driven by defects. These findings broaden the potential of multiferroics towards photonics and thin film acousto-optic devices, and suggest exciting device opportunities arising from the coupling of ferroic, piezoelectric and optical responses. PMID:26923332

  16. Deposition of device quality, low hydrogen content, hydrogenated amorphous silicon at high deposition rates with increased stability using the hot wire filament technique

    DOEpatents

    Molenbroek, Edith C.; Mahan, Archie Harvin; Gallagher, Alan C.

    2000-09-26

    A method or producing hydrogenated amorphous silicon on a substrate, comprising the steps of: positioning the substrate in a deposition chamber at a distance of about 0.5 to 3.0 cm from a heatable filament in the deposition chamber; maintaining a pressure in said deposition chamber in the range of about 10 to 100 millitorr and pressure times substrate-filament spacing in the range of about 10 to 100 millitorr-cm, heating the filament to a temperature in the range of about 1,500 to 2,000.degree. C., and heating the substrate to a surface temperature in the range of about 280 to 475.degree. C.; and flowing silicohydride gas into the deposition chamber with said heated filament, decomposing said silicohydride gas into silicon and hydrogen atomic species and allowing products of gas reactions between said atomic species and the silicohydride gas to migrate to and deposit on said substrate while adjusting and maintaining said pressure times substrate-filament spacing in said deposition chamber at a value in said 10 to 100 millitorr range to produce statistically about 3 to 50 atomic collisions between the silicon and hydrogen atomic species migrating to said substrate and undecomposed molecules of the silane or other silicohydride gas in the deposition chamber.

  17. Formation of metal oxides by cathodic arc deposition

    SciTech Connect

    Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.

    1995-03-01

    Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.

  18. Studies of the synthesis and deposition of Cu3BiS 3 for use in photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Epstein, Joshua A.

    As the world's climate continues to change, alternative energy is being adopted more and more. Solar energy is one extremely promising candidate to supplement our ever increasing energy needs. In order for it to be a viable solution, more efficient and less expensive solar panels must be made. While silicon solar panels are the current market leader their high manufacturing energy input and cost warrant looking into alternatives. Many thin film solar materials are being investigated such as CdTe, CIGS and CZTS, but all come with their own drawbacks. With a near ideal band gap, low toxicity and earth abundant elemental make up copper bismuth sulfide, Cu3BiS3, is a promising candidate for use in future photovoltaic devices. The research presented here details multiple methods to synthesize and deposit this material with an effort to keep the methods low cost, energy efficient and environmentally friendly. Multiple low temperature solvothermal routes to synthesizing copper bismuth sulfide, CBS, have been developed. The resulting powders have been verified as pure Cu3BiS3 via XRD peak matching. The precursor reactants tested for use were copper and bismuth nitrates, acetates, chlorides and hydroxides. L-cystine, L-cysteine, thiourea and CS2 have all been tested for use as sulfur sources. Seven of these combinations produced pure CBS powders. Two custom built benchtop reactors have been designed and fabricated with the aim of studying the possibility of a continuous flow reactor as a way to utilize these precipitation chemistries for making thin films of CBS. Heat and liquid flow simulations were performed in COMSOL multiphysics to assist in the reactor design process. The second reactor was designed to promote uniform liquid flow across the fluorine doped, tin oxide coated, FTO, glass. This reactor was also built with a temperature gradient transverse to the liquid flow so that the optimal temperature for the deposition of CBS could be evaluated. This reactor was also

  19. Novel microwave assisted sol–gel synthesis (MW-SGS) and electrochromic performance of petal like h-WO{sub 3} thin films

    SciTech Connect

    Kharade, Rohini R.; Patil, K.R.; Patil, P.S.; Bhosale, P.N.

    2012-07-15

    Graphical abstract: Electrochromic intercalation and deintercalation of Li{sup +} ions and electrons is facilitated by providing hexagonal tunnel, trigonal cavity and square window which allows easy and fast insertion and extraction of ions. Highlights: ► Novel two step MW-SGS is first time employed to prepare WO{sub 3} thin films. ► MW-SGS is simple and cost effective technique for preparation of nanostructures. ► Petal-like hexagonal WO{sub 3} nanodisks were successfully deposited. ► O/W ratio calculated by XPS studies is 2.89. ► Good electrochromic performance suggests practical usability of proposed technique. -- Abstract: Use of domestic microwave oven is first time employed for chemical deposition of nanocrystalline hexagonal WO{sub 3} (h-WO{sub 3}) thin films. Low cost precursors like sodium tungstate, hydrochloric acid, oxalic acid and potassium sulfate signifies cost effectiveness of this thin film fabrication route. Scanning electron microscopy images reveal formation of petal like nanodisks. A number of analytical techniques were used to characterize the WO{sub 3} petal like nanodisks, including X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy, FT-IR spectroscopy, Raman scattering spectroscopy, UV–visible spectrophotometry and cyclic voltammetry (CV). The X-ray photoelectron spectroscopic studies revealed 2.89 O/W atomic ratio. The electrical transport studies on WO{sub 3} thin films show semiconducting behavior with n-type semiconductivity. The value of determined coloration efficiency is 57.90 cm{sup 2}/C. The mechanism of Li{sup +} intercalation and deinercalation in h-WO{sub 3} matrix is proposed for enhanced electrochromism.

  20. Visual quality assessment of electrochromic and conventional glazings

    SciTech Connect

    Moeck, M.; Lee, E.S.; Rubin, M.D.; Sullivan, R.; Selkowitz, S.E.

    1996-09-01

    Variable transmission, ``switchable`` electrochromic glazings are compared to conventional static glazings using computer simulations to assess the daylighting quality of a commercial office environment where paper and computer tasks are performed. RADIANCE simulations were made for a west-facing commercial office space under clear and overcast sky conditions. This visualization tool was used to model different glazing types, to compute luminance and illuminance levels, and to generate a parametric set of photorealistic images of typical interior views at various times of the day and year. Privacy and visual display terminal (VDT) visibility is explored. Electrochromic glazings result in a more consistent glare-free daylit environment compared to their static counterparts. However, if the glazing is controlled to minimize glare or to maintain low interior daylight levels for critical visual tasks (e.g, VDT), occupants may object to the diminished quality of the outdoor view due to its low transmission (Tv = 0.08) during those hours. RADIANCE proved to be a very powerful tool to better understand some of the design tradeoffs of this emerging glazing technology. The ability to draw specific conclusions about the relative value of different technologies or control strategies is limited by the lack of agreed upon criteria or standards for lighting quality and visibility.

  1. Atomic layer deposition of Hf{sub x}Al{sub y}C{sub z} as a work function material in metal gate MOS devices

    SciTech Connect

    Lee, Albert Fuchigami, Nobi; Pisharoty, Divya; Hong, Zhendong; Haywood, Ed; Joshi, Amol; Mujumdar, Salil; Bodke, Ashish; Karlsson, Olov; Kim, Hoon; Choi, Kisik; Besser, Paul

    2014-01-15

    As advanced silicon semiconductor devices are transitioning from planar to 3D structures, new materials and processes are needed to control the device characteristics. Atomic layer deposition (ALD) of Hf{sub x}Al{sub y}C{sub z} films using hafnium chloride and trimethylaluminum precursors was combined with postdeposition anneals and ALD liners to control the device characteristics in high-k metal-gate devices. Combinatorial process methods and technologies were employed for rapid electrical and materials characterization of various materials stacks. The effective work function in metal–oxide–semiconductor capacitor devices with the Hf{sub x}Al{sub y}C{sub z} layer coupled with an ALD HfO{sub 2} dielectric was quantified to be mid-gap at ∼4.6 eV. Thus, Hf{sub x}Al{sub y}C{sub z} is a promising metal gate work function material that allows for the tuning of device threshold voltages (V{sub th}) for anticipated multi-V{sub th} integrated circuit devices.

  2. Enhanced performance of CdS/CdTe thin-film devices through temperature profiling techniques applied to close-spaced sublimation deposition

    SciTech Connect

    Xiaonan Li; Sheldon, P.; Moutinho, H.; Matson, R.

    1996-05-01

    The authors describe a methodology developed and applied to the close-spaced sublimation technique for thin-film CdTe deposition. The developed temperature profiles consisted of three discrete temperature segments, which the authors called the nucleation, plugging, and annealing temperatures. They have demonstrated that these temperature profiles can be used to grow large-grain material, plug pinholes, and improve CdS/CdTe photovoltaic device performance by about 15%. The improved material and device properties have been obtained while maintaining deposition temperatures compatible with commercially available substrates. This temperature profiling technique can be easily applied to a manufacturing environment by adjusting the temperature as a function of substrate position instead of time.

  3. Preliminary Assessment of the Energy-Saving Potential of Electrochromic Windows in Residential Buildings

    SciTech Connect

    Roberts, D. R.

    2009-12-01

    Electrochromic windows provide variable tinting that can help control glare and solar heat gain. We used BEopt software to evaluate their performance in prototypical energy models of a single-family home.

  4. Durable electrooptic devices comprising ionic liquids

    DOEpatents

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.

    2006-10-10

    Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes.

  5. Lithium-titanate-nanotube-supported WO3 for enhancing transmittance contrast in electrochromics.

    PubMed

    Dong, Yunbing; Xiong, Chunrong; Zhang, Yilu; Xing, Shuai; Jiang, Hong

    2016-03-11

    Lithium titanate nanotubes (Li-TNTs) have been successfully synthesized. The inner and outer diameters of the nanotubes are 5 nm and 8 nm with an interlayer spacing of 0.83 nm. The nanotubes were in accordance with the Li1.81H0.19Ti2O5 · xH2O phase. The chemical component was Li0.9H1.1Ti2O5 · H2O as determined by ICP-AES. The Li-TNT-supported WO3 nanoparticle (WO3/Li-TNTs) thin film was prepared onto ITO glass via spin-coating and then fabricated with an electrochromic device. The Li ion diffusion coefficient in the WO3/Li-TNT film was 6.1 × 10(-10) cm(2) s(-1), which is eight times higher than that for the pure WO3 film. The transmittance contrast of the pure WO3-based ECD was 53.3% at 600 nm. However, this increased to 74.1% for the WO3/Li-TNT-based ECD. Meanwhile, the color-switching times of the WO3/Li-TNT-based ECD were apparently shorter than the ones for the WO3-based ECD. PMID:26866352

  6. Lithium-titanate-nanotube-supported WO3 for enhancing transmittance contrast in electrochromics

    NASA Astrophysics Data System (ADS)

    Dong, Yunbing; Xiong, Chunrong; Zhang, Yilu; Xing, Shuai; Jiang, Hong

    2016-03-01

    Lithium titanate nanotubes (Li-TNTs) have been successfully synthesized. The inner and outer diameters of the nanotubes are 5 nm and 8 nm with an interlayer spacing of 0.83 nm. The nanotubes were in accordance with the Li1.81H0.19Ti2O5 · xH2O phase. The chemical component was Li0.9H1.1Ti2O5 · H2O as determined by ICP-AES. The Li-TNT-supported WO3 nanoparticle (WO3/Li-TNTs) thin film was prepared onto ITO glass via spin-coating and then fabricated with an electrochromic device. The Li ion diffusion coefficient in the WO3/Li-TNT film was 6.1 × 10-10 cm2 s-1, which is eight times higher than that for the pure WO3 film. The transmittance contrast of the pure WO3-based ECD was 53.3% at 600 nm. However, this increased to 74.1% for the WO3/Li-TNT-based ECD. Meanwhile, the color-switching times of the WO3/Li-TNT-based ECD were apparently shorter than the ones for the WO3-based ECD.

  7. Deposition of (90)YPO(4) and (144)CePO(4) radioisotopes on polymer surfaces for radiation delivery devices.

    PubMed

    Qu, Xin; Weinberger, Judah

    2002-01-01

    Intravascular irradiation with beta emitters inhibits restenosis in arteries after balloon angioplasty or stent implantation. Yttrium-90 ((90)Y, T(1/2)=64 h) and cerium-144 ((144)Ce, T(1/2)=286 d) emit beta particles (E(max)=2.28--3.50 MeV) having an ideal energy range for brachytherapy delivery system. In this article, a previously reported method for depositing (32)P on poly(ethylene terephtalate) (PET) surfaces is generalized and modifications that allow deposition of other beta-emitting radioisotopes, such as (90)Y and (144)Ce, are demonstrated. PET films were first coated with chitosan hydrogel and then adsorbed different amounts of phosphoric acid (PA) in aqueous solutions. Yttrium was deposited onto the surface as YPO(4) after the films were immersed in YCl(3) solutions. 1 muCi (90)YCl(3) (2 x 10(-9) g) was used in each sample as a tracer for measuring the deposition efficiency, which is defined as the percentage of YCl(3) deposited on the surface compared to the amount of YCl(3) in solutions before the deposition. In order to improve the safety of brachytherapy treatments, polyurethanes were used to seal the deposited radioisotopes on the surface to minimize the leakage of the isotopes into the patients. The generality of this method presented here for a wide variety of particular radioisotopic components allows design of a broad range of versatile radioisotope sources. PMID:11870641

  8. Organic Vapor Phase Deposition (OVPD) for efficient OLED manufacturing: the specific advantages and possibilities of carrier-gas enhanced vapor phase deposition for the manufacturing of organic thin film devices

    NASA Astrophysics Data System (ADS)

    Kreis, Juergen; Schwambera, Markus; Keiper, Dietmar; Gersdorff, Markus; Long, Michael; Heuken, Michael

    2012-09-01

    Being introduced more than 20 years ago, OLEDs have seen a strong push in particular in the last two years, mostly driven by key players in the flat panel display industry. The majority of OLEDs manufactured today are deposited by vacuum thermal evaporation (VTE). Whilst this approach enables the making of high-performance devices scaling up of this approach has met new challenges when substrate dimensions are exceeding the "proof-of-principle" dimensions of pilot lines. Total production costs are increasingly moving into the focus of consideration. With Organic Vapor Phase Deposition (OVPD), AIXTRON has commercialized the principle of utilizing inert carriergas for the transport and controlled condensation of small molecules. While the original concept had been proposed by Prof. Steven Forrest at Princeton University, AIXTRON added its expertise in scaling gas phase processes to make this technology applicable for high-throughput production. Combining the basic concept of OVPD with AIXTRON's comprehensive expertise in utilizing close coupled showerheads and the underlying scaling rules, the disruptive approach offers a number of significant advantages: 1) decoupling of evaporation source and deposition system: additional freedom and independent optimization of source design and deposition area; 2) Utilization of carrier-gas for a more efficient evaporation, potentially increasing process windows; 3) Close-coupled showerhead approach realizes high material utilization with homogeneity; 4) Control of deposition rates by carrier-gas flow instead of the evaporation temperature enables precise rates control, co-deposition of various materials at changing rates. This paper will discuss the most significant differences compared to VTE and explain how the approach addresses requirements for efficient scaling as well as enabling advanced structure designs.

  9. Advances in pulsed-laser-deposited AIN thin films for high-temperature capping, device passivation, and piezoelectric-based RF MEMS/NEMS resonator applications

    NASA Astrophysics Data System (ADS)

    Hullavarad, S. S.; Vispute, R. D.; Nagaraj, B.; Kulkarni, V. N.; Dhar, S.; Venkatesan, T.; Jones, K. A.; Derenge, M.; Zheleva, T.; Ervin, M. H.; Lelis, A.; Scozzie, C. J.; Habersat, D.; Wickenden, A. E.; Currano, L. J.; Dubey, M.

    2006-04-01

    In this paper we report recent advances in pulsed-laser-deposited AIN thin films for high-temperature capping of SiC, passivation of SiC-based devices, and fabrication of a piezoelectric MEMS/NEMS resonator on Pt-metallized SiO2/Si. The AlN films grown using the reactive laser ablation technique were found to be highly stoichiometric, dense with an optical band gap of 6.2 eV, and with a surface smoothness of less than 1 nm. A low-temperature buffer-layer approach was used to reduce the lattice and thermal mismatch strains. The dependence of the quality of AlN thin films and its characteristics as a function of processing parameters are discussed. Due to high crystallinity, near-perfect stoichiometry, and high packing density, pulsed-laser-deposited AlN thin films show a tendency to withstand high temperatures up to 1600°C, and which enables it to be used as an anneal capping layer for SiC wafers for removing ion-implantation damage and dopant activation. The laser-deposited AlN thin films show conformal coverage on SiC-based devices and exhibit an electrical break-down strength of 1.66 MV/cm up to 350°C when used as an insulator in Ni/AlN/SiC metal-insulator-semiconductor (MIS) devices. Pulsed laser deposition (PLD) AlN films grown on Pt/SiO2/Si (100) substrates for radio-frequency microelectrical and mechanical systems and nanoelectrical and mechanical systems (MEMS and NEMS) demonstrated resonators having high Q values ranging from 8,000 to 17,000 in the frequency range of 2.5-0.45 MHz. AlN thin films were characterized by x-ray diffraction, Rutherford backscattering spectrometry (in normal and oxygen resonance mode), atomic force microscopy, ultraviolet (UV)-visible spectroscopy, and scanning electron microscopy. Applications exploiting characteristics of high bandgap, high bond strength, excellent piezoelectric characteristics, extremely high chemical inertness, high electrical resistivity, high breakdown strength, and high thermal stability of the pulsed-laser-deposited

  10. Technologies for deposition of transition metal oxide thin films: application as functional layers in “Smart windows” and photocatalytic systems

    NASA Astrophysics Data System (ADS)

    Gesheva, K.; Ivanova, T.; Bodurov, G.; Szilágyi, I. M.; Justh, N.; Kéri, O.; Boyadjiev, S.; Nagy, D.; Aleksandrova, M.

    2016-02-01

    “Smart windows” are envisaged for future low-energy, high-efficient architectural buildings, as well as for the car industry. By switching from coloured to fully bleached state, these windows regulate the energy of solar flux entering the interior. Functional layers in these devices are the transition metals oxides. The materials (transitional metal oxides) used in smart windows can be also applied as photoelectrodes in water splitting photocells for hydrogen production or as photocatalytic materials for self-cleaning surfaces, waste water treatment and pollution removal. Solar energy utilization is recently in the main scope of numerous world research laboratories and energy organizations, working on protection against conventional fuel exhaustion. The paper presents results from research on transition metal oxide thin films, fabricated by different methods - atomic layer deposition, atmospheric pressure chemical vapour deposition, physical vapour deposition, and wet chemical methods, suitable for flowthrough production process. The lower price of the chemical deposition processes is especially important when the method is related to large-scale glazing applications. Conclusions are derived about which processes are recently considered as most prospective, related to electrochromic materials and devices manufacturing.

  11. Light modulating device

    SciTech Connect

    Rauh, R.D.; Goldner, R.B.

    1989-12-26

    In a device for transmitting light, means for controlling the transmissivity of the device, including a ceramic, reversibly electrochromic, crystalline element having a highly reflective state when injected with electrons and charge compensating ions and a highly transmissive state when the electrons and ions are removed, the crystalline element being characterized as having a reflectivity of at least 50% in the reflective state and not greater than 10% in the transmissive state, and means for modulating the crystalline element between the reflective and transmissive states by injecting ions into the crystalline element in response to an applied electrical current of a first polarity and removing the ions in response to an applied electrical current of a second polarity are disclosed. 1 fig.

  12. Light modulating device

    DOEpatents

    Rauh, R. David; Goldner, Ronald B.

    1989-01-01

    In a device for transmitting light, means for controlling the transmissivity of the device, including a ceramic, reversibly electrochromic, crystalline element having a highly reflective state when injected with electrons and charge compensating ions and a highly transmissive state when the electrons and ions are removed, the crystalline element being characterized as having a reflectivity of at least 50% in the reflective state and not greater than 10% in the transmissive state, and means for modulating the crystalline element between the reflective and transmissive states by injecting ions into the crystalline element in response to an applied electrical current of a first polarity and removing the ions in response to an applied electrical current of a second polarity.

  13. Work function tuning of plasma-enhanced atomic layer deposited WC{sub x}N{sub y} electrodes for metal/oxide/semiconductor devices

    SciTech Connect

    Zonensain, Oren; Fadida, Sivan; Eizenberg, Moshe; Fisher, Ilanit; Gao, Juwen; Chattopadhyay, Kaushik; Harm, Greg; Mountsier, Tom; Danek, Michal

    2015-02-23

    One of the main challenges facing the integration of metals as gate electrodes in advanced MOS devices is control over the Fermi level position at the metal/dielectric interface. In this study, we demonstrate the ability to tune the effective work function (EWF) of W-based electrodes by process modifications of the atomic layer deposited (ALD) films. Tungsten carbo-nitrides (WC{sub x}N{sub y}) films were deposited via plasma-enhanced and/or thermal ALD processes using organometallic precursors. The process modifications enabled us to control the stoichiometry of the WC{sub x}N{sub y} films. Deposition in hydrogen plasma (without nitrogen based reactant) resulted in a stoichiometry of WC{sub 0.4} with primarily W-C chemical bonding, as determined by x-ray photoelectron spectroscopy. These films yielded a relatively low EWF of 4.2 ± 0.1 eV. The introduction of nitrogen based reactant to the plasma or the thermal ALD deposition resulted in a stoichiometry of WC{sub 0.1}N{sub 0.6–0.8} with predominantly W-N chemical bonding. These films produced a high EWF of 4.7 ± 0.1 eV.

  14. Improving the dielectric properties of an electrowetting-on-dielectric microfluidic device with a low-pressure chemical vapor deposited Si3N4 dielectric layer.

    PubMed

    Shen, Hsien-Hua; Chung, Lung-Yuan; Yao, Da-Jeng

    2015-03-01

    Dielectric breakdown is a common problem in a digital microfluidic system, which limits its application in chemical or biomedical applications. We propose a new fabrication of an electrowetting-on-dielectric (EWOD) device using Si3N4 deposited by low-pressure chemical vapor deposition (LPCVD) as a dielectric layer. This material exhibits a greater relative permittivity, purity, uniformity, and biocompatibility than polymeric films. These properties also increase the breakdown voltage of a dielectric layer and increase the stability of an EWOD system when applied in biomedical research. Medium droplets with mouse embryos were manipulated in this manner. The electrical properties of the Si3N4 dielectric layer-breakdown voltage, refractive index, relative permittivity, and variation of contact angle with input voltage-were investigated and compared with a traditional Si3N4 dielectric layer deposited as a plasma-enhanced chemical vapor deposition to confirm the potential of LPCVD Si3N4 applied as the dielectric layer of an EWOD digital microfluidic system.

  15. Improving the dielectric properties of an electrowetting-on-dielectric microfluidic device with a low-pressure chemical vapor deposited Si3N4 dielectric layer

    PubMed Central

    Shen, Hsien-Hua; Chung, Lung-Yuan

    2015-01-01

    Dielectric breakdown is a common problem in a digital microfluidic system, which limits its application in chemical or biomedical applications. We propose a new fabrication of an electrowetting-on-dielectric (EWOD) device using Si3N4 deposited by low-pressure chemical vapor deposition (LPCVD) as a dielectric layer. This material exhibits a greater relative permittivity, purity, uniformity, and biocompatibility than polymeric films. These properties also increase the breakdown voltage of a dielectric layer and increase the stability of an EWOD system when applied in biomedical research. Medium droplets with mouse embryos were manipulated in this manner. The electrical properties of the Si3N4 dielectric layer—breakdown voltage, refractive index, relative permittivity, and variation of contact angle with input voltage—were investigated and compared with a traditional Si3N4 dielectric layer deposited as a plasma-enhanced chemical vapor deposition to confirm the potential of LPCVD Si3N4 applied as the dielectric layer of an EWOD digital microfluidic system. PMID:25825614

  16. Flame Aerosol Deposition of TiO2 Nanoparticle Films on Polymers and Polymeric Microfluidic Devices for On-Chip Phosphopeptide Enrichment.

    PubMed

    Rudin, Thomas; Tsougeni, Katerina; Gogolides, Evangelos; Pratsinis, Sotiris E

    2012-09-01

    Direct and fast (10s of seconds) deposition of flame-made, high surface-area aerosol films on polymers and polymeric microfluidic devices is demonstrated. Uniform TiO2 nanoparticle films were deposited on cooled Poly(methyl methacrylate) (PMMA) substrates by combustion of titanium(IV) isopropoxide (TTIP) - xylene solution sprays. Films were mechanically stabilized by in-situ annealing with a xylene spray flame. Plasma-etched microfluidic chromatography columns, comprising parallel microchannels were also coated with such nanoparticle films without any microchannel deformation. These microcolumns were successfully used in metal-oxide affinity chromatography (MOAC) to selectively trap phosphopeptides on these high surface-area nanostructured films. The chips had a high capacity retaining 1.2 μg of standard phosphopeptide. A new extremely fast method is developed for MOAC microchip stationary phase fabrication with applications in proteomics. PMID:23729946

  17. Flame Aerosol Deposition of TiO2 Nanoparticle Films on Polymers and Polymeric Microfluidic Devices for On-Chip Phosphopeptide Enrichment

    PubMed Central

    Rudin, Thomas; Tsougeni, Katerina; Gogolides, Evangelos; Pratsinis, Sotiris E.

    2013-01-01

    Direct and fast (10s of seconds) deposition of flame-made, high surface-area aerosol films on polymers and polymeric microfluidic devices is demonstrated. Uniform TiO2 nanoparticle films were deposited on cooled Poly(methyl methacrylate) (PMMA) substrates by combustion of titanium(IV) isopropoxide (TTIP) – xylene solution sprays. Films were mechanically stabilized by in-situ annealing with a xylene spray flame. Plasma-etched microfluidic chromatography columns, comprising parallel microchannels were also coated with such nanoparticle films without any microchannel deformation. These microcolumns were successfully used in metal-oxide affinity chromatography (MOAC) to selectively trap phosphopeptides on these high surface-area nanostructured films. The chips had a high capacity retaining 1.2 μg of standard phosphopeptide. A new extremely fast method is developed for MOAC microchip stationary phase fabrication with applications in proteomics. PMID:23729946

  18. Spectral selectivity of electrochromic windows with color state for all-sky conditions

    SciTech Connect

    Soule, D E; Zhang, J G; Benson, D K

    1995-07-01

    The optical performance of an electrochromic window is studied for the visible, ultraviolet, and near infrared spectral regions. The performance is found to deviate strongly with window color state and for clear or cloudy skies. A new spectral cloud model is applied to an electrochromic window recently developed at NREL. A spectral comparison is made between the electrochromic window and spectrally selective standard windows. Two series of double-glazed window sections, including the electrochromic window with color state and a series of low-E windows, were measured for transmittance and reflectance (300-2500nm), With these spectral data, a new near-infrared blocking (reflection + absorption) factor is developed for window application in warm climates for cooling load reduction. A chromaticity analysis is presented for both the daylight spectra and the transmitted electrochromic window spectra with color state, Computed daylight correlated color temperatures show a wide range, with values of 5660K for clear global irradiation, 6210K for clouds, and 13,250K for a zenith blue sky. Chromatic trajectories with color state for transmitted radiation extend further toward the blue to 8180K for the global and 28,990K for zenith sky irradiation.

  19. Lighting energy savings potential of split-pane electrochromic windows controlled for daylighting with visual comfort

    SciTech Connect

    Software, Anyhere; Fernandes, Luis; Lee, Eleanor; Ward, Greg

    2013-03-15

    A simulation study was conducted to evaluate lighting energy savings of split-pane electrochromic (EC) windows controlled to satisfy key visual comfort parameters. Using the Radiance lighting simulation software, interior illuminance and luminance levels were computed for a south-facing private office illuminated by a window split into two independently-controlled EC panes. The transmittance of these was optimized hourly for a workplane illuminance target while meeting visual comfort constraints, using a least-squares algorithm with linear inequality constraints. Blinds were successively deployed until visual comfort criteria were satisfied. The energy performance of electrochromics proved to be highly dependent on how blinds were controlled. With hourly blind position adjustments, electrochromics showed significantly higher (62percent and 53percent, respectively without and with overhang) lighting energy consumption than clear glass. With a control algorithm designed to better approximate realistic manual control by an occupant, electrochromics achieved significant savings (48percent and 37percent, respectively without and with overhang). In all cases, energy consumption decreased when the workplace illuminance target was increased. In addition, the fraction of time during which the occupant had an unobstructed view of the outside was significantly greater with electrochromics: 10 months out of the year versus a handful of days for the reference case.

  20. Hole doping in Al-containing nickel oxide materials to improve electrochromic performance.

    PubMed

    Lin, Feng; Nordlund, Dennis; Weng, Tsu-Chien; Moore, Rob G; Gillaspie, Dane T; Dillon, Anne C; Richards, Ryan M; Engtrakul, Chaiwat

    2013-01-23

    Electrochromic materials exhibit switchable optical properties that can find applications in various fields, including smart windows, nonemissive displays, and semiconductors. High-performing nickel oxide electrochromic materials have been realized by controlling the material composition and tuning the nanostructural morphology. Post-treatment techniques could represent efficient and cost-effective approaches for performance enhancement. Herein, we report on a post-processing ozone technique that improves the electrochromic performance of an aluminum-containing nickel oxide material in lithium-ion electrolytes. The resulting materials were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy, and X-ray absorption spectroscopy (XAS). It was observed that ozone exposure increased the Ni oxidation state by introducing hole states in the NiO(6) octahedral unit. In addition, ozone exposure gives rise to higher-performing aluminum-containing nickel oxide films, relative to nickel oxide containing both Al and Li, in terms of switching kinetics, bleached-state transparency, and optical modulation. The improved performance is attributed to the decreased crystallinity and increased nickel oxidation state in aluminum-containing nickel oxide electrochromic films. The present study provides an alternative route to improve electrochromic performance for nickel oxide materials. PMID:23249159

  1. Effect of multilayered SrSSrS: CeSrS phosphor prepared by multi-source deposition method on the thin film electroluminescent devices

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Kim, D. H.; Ju, B. K.; Yeom, T. H.; S Hahn, T.; Oh, M. H.; Choh, S. H.

    1995-02-01

    Single-layer SrS: Ce and multilayer SrSSrS: CeSrS thin films have been grown by multi-source deposition method. The X-ray diffraction patterns of the films showed the typical diffraction patterns of the cubic SrS powder. Single-layer SrS: Ce thin films exhibited sulfur deficiency and their fluorescence spectra showed a broad red emission peak. The multilayer SrSSrS: CeSrS electroluminescent device showed nearly stoichiometric composition and an electroluminescent device made of these layers displayed a green-emission intensified spectrum with peaks located at 493 and 523 nm. A distinct S-shaped pinching effect in the transferred charge versus applied voltage characteristics, similar to a hysteretic electroluminescent device, was observed in multilayer device. We interpret that the separation of the light-emitting SrS: Ce layer from the two interfacial SrS layers and the resulting nonuniform space charge in the middle SrS: Ce layer are responsible for the observed enhancement of luminance through the intensified hysteretic effect in the multilayer structure.

  2. Low-cost, highly transparent flexible low-e coating film to enable electrochromic windows with increased energy savings

    SciTech Connect

    Berland, Brian; Hollingsworth, Russell

    2015-03-31

    Five Quads of energy are lost through windows annually in the U.S. Low-e coatings are increasingly employed to reduce the wasted energy. Most commonly, the low-e coating is an oxide material applied directly to the glass at high temperature. With over 100,000,000 existing homes, a retrofit product is crucial to achieve widespread energy savings. Low-e films, i.e. coatings on polymeric substrates, are now also available to meet this need. However, the traditional oxide materials and process is incompatible with low temperature plastics. Alternate high performing low-e films typically incorporate materials that limit visible transmission to 35% or less. Further, the cost is high. The objective of this award was to develop a retrofit, integrated low-e/electrochromic window film to dramatically reduce energy lost through windows. While field testing of state-of-the-art electrochromic (EC) windows show the energy savings are maximized if a low-e coating is used in conjunction with the EC, available low-e films have a low visible transmission (~70% or less) that limits the achievable clear state and therefore, appearance and energy savings potential. Comprehensive energy savings models were completed at Lawrence Berkeley National Lab (LBNL). A parametric approach was used to project energy usage for windows with a large range of low-e properties across all U.S. climate zones, without limiting the study to materials that had already been produced commercially or made in a lab. The model enables projection of energy savings for low-e films as well as integrated low-e/EC products. This project developed a novel low-e film, optimized for compatibility with EC windows, using low temperature, high deposition rate processes for the growth of low-e coatings on plastic films by microwave plasma enhanced chemical vapor deposition. Silica films with good density and optical properties were demonstrated at deposition rates as high as 130Å/sec. A simple bi-layer low-e stack of

  3. Epitaxial growth of group III-nitride films by pulsed laser deposition and their use in the development of LED devices

    NASA Astrophysics Data System (ADS)

    Li, Guoqiang; Wang, Wenliang; Yang, Weijia; Wang, Haiyan

    2015-11-01

    Recently, pulsed laser deposition (PLD) technology makes viable the epitaxial growth of group III-nitrides on thermally active substrates at low temperature. The precursors generated from the pulsed laser ablating the target has enough kinetic energy when arriving at substrates, thereby effectively suppressing the interfacial reactions between the epitaxial films and the substrates, and eventually makes the film growth at low temperature possible. So far, high-quality group III-nitride epitaxial films have been successfully grown on a variety of thermally active substrates by PLD. By combining PLD with other technologies such as laser rastering technique, molecular beam epitaxy (MBE), and metal-organic chemical vapor deposition (MOCVD), III-nitride-based light-emitting diode (LED) structures have been realized on different thermally active substrates, with high-performance LED devices being demonstrated. This review focuses on the epitaxial growth of group III-nitrides on thermally active substrates by PLD and their use in the development of LED devices. The surface morphology, interfacial property between film and substrate, and crystalline quality of as-grown group III-nitride films by PLD, are systematically reviewed. The corresponding solutions for film homogeneity on large size substrates, defect control, and InGaN films growth by PLD are also discussed in depth, together with introductions to some newly developed technologies for PLD in order to realize LED structures, which provides great opportunities for commercialization of LEDs on thermally active substrates.

  4. Research Update: Atmospheric pressure spatial atomic layer deposition of ZnO thin films: Reactors, doping, and devices

    SciTech Connect

    Hoye, Robert L. Z. E-mail: jld35@cam.ac.uk; MacManus-Driscoll, Judith L. E-mail: jld35@cam.ac.uk; Muñoz-Rojas, David; Nelson, Shelby F.; Illiberi, Andrea; Poodt, Paul

    2015-04-01

    Atmospheric pressure spatial atomic layer deposition (AP-SALD) has recently emerged as an appealing technique for rapidly producing high quality oxides. Here, we focus on the use of AP-SALD to deposit functional ZnO thin films, particularly on the reactors used, the film properties, and the dopants that have been studied. We highlight how these films are advantageous for the performance of solar cells, organometal halide perovskite light emitting diodes, and thin-film transistors. Future AP-SALD technology will enable the commercial processing of thin films over large areas on a sheet-to-sheet and roll-to-roll basis, with new reactor designs emerging for flexible plastic and paper electronics.

  5. Photoelectric conversion and electrochromic properties of lutetium tetrakis(tert-butyl)bisphthalocyaninate

    SciTech Connect

    Hu, Andrew Teh; Hu Tenyi; Liu Lungchang

    2003-12-10

    Both photoelectric and electrochromic effects on lutetium tetrakis(tert-butyl)bisphthalocyaninate (Lu(TBPc){sub 2}) have been carried out in this study. Lu(TBPc){sub 2} is known for its electrochromic performance, but its photoelectric effect has not mentioned in the literature. The electrochromic properties of Lu(TBPc){sub 2} have been measured by cyclic voltammetry (CV) and UV-Vis spectrometer at the same time. It takes less than 1.5 s for the color to change from red to green under 0.9 V. Its cycle life is at least over 500 times. Furthermore, we also investigate its photoelectric conversion properties. Its photoelectric cell exhibits a positive photo-electricity conversion effect with a short-circuit photocurrent (46.4 {mu}A/cm{sup 2}) under illumination of white light (1.201 mW/cm{sup 2})

  6. Multichromophoric electrochromic polymers: colour tuning of conjugated polymers through the side chain functionalization approach.

    PubMed

    Beverina, L; Pagani, G A; Sassi, M

    2014-05-28

    Organic electrochromic materials have gained constantly increasing interest over the years with respect to their inorganic counterpart due to essentially two distinctive characteristics: their processability through solution based low cost processes and their wide colour palette. Such characteristic features enabled their application in displays, smart windows, electronic paper and ophthalmic lenses. Alongside the established concept of donor-acceptor polymers, side chain functionalized multichromophoric polymers are gaining attention as a highly performing and synthetically feasible alternative, particularly relevant to applications requiring a complete colourlessness in one of the accessible redox states of the material. The primary aim of the present article is to review all the results involving the tuning of the native electrochromic properties of simple conjugated polymers through the introduction of a discrete electrochromic molecule as a side chain substituent. PMID:24647618

  7. Effect of deposition parameters on structural and mechanical properties of niobium nitride synthesized by plasma focus device

    NASA Astrophysics Data System (ADS)

    Siddiqui, Jamil; Hussain, Tousif; Ahmad, Riaz; Khalid, Nida

    2015-06-01

    Effects of deposition angle and axial distance on the structural and mechanical properties of niobium nitride synthesized by a dense plasma focus (DPF) system are studied. The x-ray diffraction (XRD) confirms that the deposition parameters affect the growth of multi-phase niobium nitride. Scanning electron microscopy (SEM) shows the granular surface morphology with strong thermally assisted coagulation effects observed at the 5-cm axial distance. The non-porous granular morphology observed at the 9-cm distance along the anode axis is different from those observed at deposition angles of 10° and 20°. Energy dispersive x-ray (EDX) spectroscopy reveals the maximum nitrogen content at the shortest (5 cm) axial position. Atomic force microscopy (AFM) exhibits that the roughness of coated films varies for coatings synthesized at different axial and angular positions, and the Vickers micro-hardness test shows that a maximum hardness value is (08.44 ± 0.01) GPa for niobium nitride synthesized at 5-cm axial distance, which is about 500% more than that of a virgin sample. Project supported by the HEC, Pakistan.

  8. A calculation of steady-state electrocoloration parameters of electrochromic systems

    SciTech Connect

    Ushakov, O.A.; Shelepin, I.V.

    1986-01-01

    Electrochromic systems based on solutions of compounds whichchange their color reversibly when electrochemical reactions take place may find wide applications in the design of laser-light modulators, light filters with variable optical density, and means for visual information display. It is the aim of this work to find the limiting steady-state values of current density and electrically induced optical density for electrochromic systems and to discuss possibilities of eliminating solution convection during current flow in them. During prolonged electrocoloration, the convection of anolyte and catholyte in opposite directions can lead to ''glistering'' or separation of the solution layer.

  9. Gene Silencing in Skin After Deposition of Self-Delivery siRNA With a Motorized Microneedle Array Device

    PubMed Central

    Hickerson, Robyn P; Wey, Winston C; Rimm, David L; Speaker, Tycho; Suh, Susie; Flores, Manuel A; Gonzalez-Gonzalez, Emilio; Leake, Devin; Contag, Christopher H; Kaspar, Roger L

    2013-01-01

    Despite the development of potent siRNAs that effectively target genes responsible for skin disorders, translation to the clinic has been hampered by inefficient delivery through the stratum corneum barrier and into the live cells of the epidermis. Although hypodermic needles can be used to transport siRNA through the stratum corneum, this approach is limited by pain caused by the injection and the small volume of tissue that can be accessed by each injection. The use of microneedle arrays is a less painful method for siRNA delivery, but restricted payload capacity limits this approach to highly potent molecules. To address these challenges, a commercially available motorized microneedle array skin delivery device was evaluated. This device combines the positive elements of both hypodermic needles and microneedle array technologies with little or no pain to the patient. Application of fluorescently tagged self-delivery (sd)-siRNA to both human and murine skin resulted in distribution throughout the treated skin. In addition, efficient silencing (78% average reduction) of reporter gene expression was achieved in a transgenic fluorescent reporter mouse skin model. These results indicate that this device effectively delivers functional sd-siRNA with an efficiency that predicts successful clinical translation. PMID:24150576

  10. Gene Silencing in Skin After Deposition of Self-Delivery siRNA With a Motorized Microneedle Array Device.

    PubMed

    Hickerson, Robyn P; Wey, Winston C; Rimm, David L; Speaker, Tycho; Suh, Susie; Flores, Manuel A; Gonzalez-Gonzalez, Emilio; Leake, Devin; Contag, Christopher H; Kaspar, Roger L

    2013-01-01

    Despite the development of potent siRNAs that effectively target genes responsible for skin disorders, translation to the clinic has been hampered by inefficient delivery through the stratum corneum barrier and into the live cells of the epidermis. Although hypodermic needles can be used to transport siRNA through the stratum corneum, this approach is limited by pain caused by the injection and the small volume of tissue that can be accessed by each injection. The use of microneedle arrays is a less painful method for siRNA delivery, but restricted payload capacity limits this approach to highly potent molecules. To address these challenges, a commercially available motorized microneedle array skin delivery device was evaluated. This device combines the positive elements of both hypodermic needles and microneedle array technologies with little or no pain to the patient. Application of fluorescently tagged self-delivery (sd)-siRNA to both human and murine skin resulted in distribution throughout the treated skin. In addition, efficient silencing (78% average reduction) of reporter gene expression was achieved in a transgenic fluorescent reporter mouse skin model. These results indicate that this device effectively delivers functional sd-siRNA with an efficiency that predicts successful clinical translation.Molecular Therapy-Nucleic Acids (2013) 2, e129; doi:10.1038/mtna.2013.56; published online 22 October 2013. PMID:24150576

  11. Impact of composition and crystallization behavior of atomic layer deposited strontium titanate films on the resistive switching of Pt/STO/TiN devices

    SciTech Connect

    Aslam, N.; Rodenbücher, C.; Szot, K.; Waser, R.; Hoffmann-Eifert, S.; Longo, V.; Roozeboom, F.; Kessels, W. M. M.

    2014-08-14

    The resistive switching (RS) properties of strontium titanate (Sr{sub 1+x}Ti{sub 1+y}O{sub 3+(x+2y)}, STO) based metal-oxide-metal structures prepared from industrial compatible processes have been investigated focusing on the effects of composition, microstructure, and device size. Metastable perovskite STO films were prepared on Pt-coated Si substrates utilizing plasma-assisted atomic layer deposition (ALD) from cyclopentadienyl-based metal precursors and oxygen plasma at 350 °C, and a subsequent annealing at 600 °C in nitrogen. Films of 15 nm and 12 nm thickness with three different compositions [Sr]/([Sr] + [Ti]) of 0.57 (Sr-rich STO), 0.50 (stoichiometric STO), and 0.46 (Ti-rich STO) were integrated into Pt/STO/TiN crossbar structures with sizes ranging from 100 μm{sup 2} to 0.01 μm{sup 2}. Nano-structural characterizations revealed a clear effect of the composition of the as-deposited STO films on their crystallization behavior and thus on the final microstructures. Local current maps obtained by local-conductivity atomic force microscopy were in good agreement with local changes of the films' microstructures. Correspondingly, also the initial leakage currents of the Pt/STO/TiN devices were affected by the STO compositions and by the films' microstructures. An electroforming process set the Pt/STO/TiN devices into the ON-state, while the forming voltage decreased with increasing initial leakage current. After a RESET process under opposite voltage has been performed, the Pt/STO/TiN devices showed a stable bipolar RS behavior with non-linear current-voltage characteristics for the high (HRS) and the low (LRS) resistance states. The obtained switching polarity and nearly area independent LRS values agree with a filamentary character of the RS behavior according to the valence change mechanism. The devices of 0.01 μm{sup 2} size with a 12 nm polycrystalline stoichiometric STO film were switched at a current compliance of 50 μA with

  12. Impact of surface morphology of Si substrate on performance of Si/ZnO heterojunction devices grown by atomic layer deposition technique

    SciTech Connect

    Hazra, Purnima; Singh, Satyendra Kumar; Jit, Satyabrata

    2015-01-01

    In this paper, the authors have investigated the structural, optical, and electrical characteristics of silicon nanowire (SiNW)/zinc oxide (ZnO) core–shell nanostructure heterojunctions and compared their characteristics with Si/ZnO planar heterojunctions to investigate the effect of surface morphology of Si substrate in the characteristics of Si/ZnO heterojunction devices. In this work, ZnO thin film was conformally deposited on both p-type 〈100〉 planar Si substrate and substrate with vertically aligned SiNW arrays by atomic layer deposition (ALD) method. The x-ray diffraction spectra show that the crystalline structures of Si/ZnO heterojunctions are having (101) preferred orientation, whereas vertically oriented SiNW/ZnO core–shell heterojunctions are having (002)-oriented wurtzite crystalline structures. The photoluminescence (PL) spectra of Si/ZnO heterojunctions show a very sharp single peak at 377 nm, corresponding to the bandgap of ZnO material with no other defect peaks in visible region; hence, these devices can have applications only in UV region. On the other hand, SiNW/ZnO heterojunctions are having band-edge peak at 378 nm along with a broad emission band, spreading almost throughout the entire visible region with a peak around 550 nm. Therefore, ALD-grown SiNW/ZnO heterojunctions can emit green and red light simultaneously. Reflectivity measurement of the heterojunctions further confirms the enhancement of visible region peak in the PL spectra of SiNW/ZnO heterojunctions, as the surface of the SiNW/ZnO heterojunctions exhibits extremely low reflectance (<3%) in the visible wavelength region compared to Si/ZnO heterojunctions (>20%). The current–voltage characteristics of both Si/ZnO and SiNW/ZnO heterojunctions are measured with large area ohmic contacts on top and bottom of the structure to compare the electrical characteristics of the devices. Due to large surface to-volume ratio of SiNW/ZnO core–shell heterojunction devices, the

  13. Electrochromism: a useful probe to study algal photosynthesis.

    PubMed

    Bailleul, Benjamin; Cardol, Pierre; Breyton, Cécile; Finazzi, Giovanni

    2010-11-01

    In photosynthesis, electron transfer along the photosynthetic chain results in a vectorial transfer of protons from the stroma to the lumenal space of the thylakoids. This promotes the generation of an electrochemical proton gradient (Δμ(H)(+)), which comprises a gradient of electric potential (ΔΨ) and of proton concentration (ΔpH). The Δμ(H)(+) has a central role in the photosynthetic process, providing the energy source for ATP synthesis. It is also involved in many regulatory mechanisms. The ΔpH modulates the rate of electron transfer and triggers deexcitation of excess energy within the light harvesting complexes. The ΔΨ is required for metabolite and protein transport across the membranes. Its presence also induces a shift in the absorption spectra of some photosynthetic pigments, resulting in the so-called ElectroChromic Shift (ECS). In this review, we discuss the characteristic features of the ECS, and illustrate possible applications for the study of photosynthetic processes in vivo. PMID:20632109

  14. Metalorganic chemical vapor deposition of CuInSe{sub 2} from copper and indium diselenocarbamates for solar cell devices

    SciTech Connect

    McAleese, J.; O`Brien, P.; Otway, D.J.

    1998-12-31

    Thin film(s) of chalcopyrite CuInSe{sub 2} have been grown by low-pressure metal-organic chemical vapor deposition (LP-MOCVD) using the precursors In(Se{sub 2}CNMe{sup n}Hexyl){sub 3} and precursors Cu(Se{sub 2}CNMe{sup n}Hexyl){sub 2}. The precursors were prepared from carbon diselenide. Films were grown on glass between 400--450 C, and characterized by X-ray diffraction, optical spectroscopy (UV/Vis), EDAX and scanning electron microscopy.

  15. Growth and characterization of III-nitrides materials system for photonic and electronic devices by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Yoo, Dongwon

    A wide variety of group III-Nitride-based photonic and electronic devices have opened a new era in the field of semiconductor research in the past ten years. The direct and large bandgap nature, intrinsic high carrier mobility, and the capability of forming heterostructures allow them to dominate photonic and electronic device market such as light emitters, photodiodes, or high-speed/high-power electronic devices. Avalanche photodiodes (APDs) based on group III-Nitrides materials are of interest due to potential capabilities for low dark current densities, high sensitivities and high optical gains in the ultraviolet (UV) spectral region. Wide-bandgap GaN-based APDs are excellent candidates for short-wavelength photodetectors because they have the capability for cut-off wavelengths in the UV spectral region (lambda < 290 nm). These intrinsically solar-blind UV APDs will not require filters to operate in the solar-blind spectral regime of lambda < 290 nm. For the growth of GaN-based heteroepitaxial layers on lattice-mismatched substrates, a high density of defects is usually introduced during the growth; thereby, causing a device failure by premature microplasma, which has been a major issue for GaN-based APDs. The extensive research on epitaxial growth and optimization of AlxGa 1-xN (0 ≤ x ≤ 1) grown on low dislocation density native bulk III-N substrates have brought UV APDs into realization. GaN and AlGaN UV p-i-n APDs demonstrated first and record-high true avalanche gain of > 10,000 and 50, respectively. The large stable optical gains are attributed to the improved crystalline quality of epitaxial layers grown on low dislocation density bulk substrates. GaN p-i-n rectifiers have brought much research interest due to its superior physical properties. The AIN-free full-vertical GaN p-i-n rectifiers on n-type 6H-SiC substrates by employing a conducting AIGaN:Si buffer layer provides the advantages of the reduction of sidewall damage from plasma etching and

  16. Evaluation of the Survivability of Microorganisms Deposited on Filtering Respiratory Protective Devices under Varying Conditions of Humidity

    PubMed Central

    Majchrzycka, Katarzyna; Okrasa, Małgorzata; Skóra, Justyna; Gutarowska, Beata

    2016-01-01

    Bioaerosols are common biological factors in work environments, which require routine use of filtering respiratory protective devices (FRPDs). Currently, no studies link humidity changes in the filter materials of such devices, during use, with microorganism survivability. Our aim was to determine the microclimate inside FRPDs, by simulating breathing, and to evaluate microorganism survivability under varying humidity conditions. Breathing was simulated using commercial filtering facepiece respirators in a model system. Polypropylene melt-blown nonwoven fabrics with moisture contents of 40%, 80%, and 200%, were used for assessment of microorganisms survivability. A modified AATCC 100-2004 method was used to measure the survivability of ATCC and NCAIM microorganisms: Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans and Aspergillus niger. During simulation relative humidity under the facepiece increased after 7 min of usage to 84%–92% and temperature increased to 29–30 °C. S. aureus survived the best on filter materials with 40%–200% moisture content. A decrease in survivability was observed for E. coli and C. albicans when mass humidity decreased. We found that B. subtilis and A. niger proliferated for 48–72 h of incubation and then died regardless of the moisture content. In conclusion, our tests showed that the survivability of microorganisms on filter materials depends on the amount of accumulated moisture and microorganism type. PMID:26742049

  17. Evaluation of the Survivability of Microorganisms Deposited on Filtering Respiratory Protective Devices under Varying Conditions of Humidity.

    PubMed

    Majchrzycka, Katarzyna; Okrasa, Małgorzata; Skóra, Justyna; Gutarowska, Beata

    2016-01-04

    Bioaerosols are common biological factors in work environments, which require routine use of filtering respiratory protective devices (FRPDs). Currently, no studies link humidity changes in the filter materials of such devices, during use, with microorganism survivability. Our aim was to determine the microclimate inside FRPDs, by simulating breathing, and to evaluate microorganism survivability under varying humidity conditions. Breathing was simulated using commercial filtering facepiece respirators in a model system. Polypropylene melt-blown nonwoven fabrics with moisture contents of 40%, 80%, and 200%, were used for assessment of microorganisms survivability. A modified AATCC 100-2004 method was used to measure the survivability of ATCC and NCAIM microorganisms: Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans and Aspergillus niger. During simulation relative humidity under the facepiece increased after 7 min of usage to 84%-92% and temperature increased to 29-30 °C. S. aureus survived the best on filter materials with 40%-200% moisture content. A decrease in survivability was observed for E. coli and C. albicans when mass humidity decreased. We found that B. subtilis and A. niger proliferated for 48-72 h of incubation and then died regardless of the moisture content. In conclusion, our tests showed that the survivability of microorganisms on filter materials depends on the amount of accumulated moisture and microorganism type.

  18. Metalorganic chemical vapor deposition and characterization of (Al,Si)O dielectrics for GaN–based devices

    DOE PAGESBeta

    Chan, Silvia; Mishra, Umesh K.; Tahhan, Maher; Liu, Xiang; Bisi, David; Gupta, Chirag; Koksaldi, Onur; Li, Haoran; Mates, Tom; DenBaars, Steven P.; et al

    2016-01-20

    In this study, we report on the growth and electrical characterization of (Al,Si)O dielectrics grown by metalorganic chemical vapor deposition (MOCVD) using trimethylaluminum, oxygen, and silane as precursors. The growth rates, refractive indices, and composition of (Al,Si)O films grown on Si(001) were determined from ellipsometry and XPS measurements. Crystallinity and electrical properties of (Al,Si)O films grown in situ on c-plane GaN were characterized using grazing incidence X-ray diffraction and capacitance–voltage with current–voltage measurements, respectively. Si concentration in the films was found to be tunable by varying the trimethylaluminum and/or oxygen precursor flows. The Si incorporation suppressed the formation of crystallinemore » domains, leading to amorphous films that resulted in reduced interfacial trap density, low gate leakage and ultra-low hysteresis in (Al,Si)O/n-GaN MOS-capacitors.« less

  19. Metalorganic chemical vapor deposition and characterization of (Al,Si)O dielectrics for GaN-based devices

    NASA Astrophysics Data System (ADS)

    Chan, Silvia H.; Tahhan, Maher; Liu, Xiang; Bisi, Davide; Gupta, Chirag; Koksaldi, Onur; Li, Haoran; Mates, Tom; DenBaars, Steven P.; Keller, Stacia; Mishra, Umesh K.

    2016-02-01

    In this paper, we report on the growth and electrical characterization of (Al,Si)O dielectrics grown by metalorganic chemical vapor deposition (MOCVD) using trimethylaluminum, oxygen, and silane as precursors. The growth rates, refractive indices, and composition of (Al,Si)O films grown on Si(001) were determined from ellipsometry and XPS measurements. Crystallinity and electrical properties of (Al,Si)O films grown in situ on c-plane GaN were characterized using grazing incidence X-ray diffraction and capacitance-voltage with current-voltage measurements, respectively. Si concentration in the films was found to be tunable by varying the trimethylaluminum and/or oxygen precursor flows. The Si incorporation suppressed the formation of crystalline domains, leading to amorphous films that resulted in reduced interfacial trap density, low gate leakage and ultra-low hysteresis in (Al,Si)O/n-GaN MOS-capacitors.

  20. A tunable electrochromic fabry-perot filter for adaptive optics applications.

    SciTech Connect

    Blaich, Jonathan David; Kammler, Daniel R.; Ambrosini, Andrea; Sweatt, William C.; Verley, Jason C.; Heller, Edwin J.; Yelton, William Graham

    2006-10-01

    The potential for electrochromic (EC) materials to be incorporated into a Fabry-Perot (FP) filter to allow modest amounts of tuning was evaluated by both experimental methods and modeling. A combination of chemical vapor deposition (CVD), physical vapor deposition (PVD), and electrochemical methods was used to produce an ECFP film stack consisting of an EC WO{sub 3}/Ta{sub 2}O{sub 5}/NiO{sub x}H{sub y} film stack (with indium-tin-oxide electrodes) sandwiched between two Si{sub 3}N{sub 4}/SiO{sub 2} dielectric reflector stacks. A process to produce a NiO{sub x}H{sub y} charge storage layer that freed the EC stack from dependence on atmospheric humidity and allowed construction of this complex EC-FP stack was developed. The refractive index (n) and extinction coefficient (k) for each layer in the EC-FP film stack was measured between 300 and 1700 nm. A prototype EC-FP filter was produced that had a transmission at 500 nm of 36%, and a FWHM of 10 nm. A general modeling approach that takes into account the desired pass band location, pass band width, required transmission and EC optical constants in order to estimate the maximum tuning from an EC-FP filter was developed. Modeling shows that minor thickness changes in the prototype stack developed in this project should yield a filter with a transmission at 600 nm of 33% and a FWHM of 9.6 nm, which could be tuned to 598 nm with a FWHM of 12.1 nm and a transmission of 16%. Additional modeling shows that if the EC WO{sub 3} absorption centers were optimized, then a shift from 600 nm to 598 nm could be made with a FWHM of 11.3 nm and a transmission of 20%. If (at 600 nm) the FWHM is decreased to 1 nm and transmission maintained at a reasonable level (e.g. 30%), only fractions of a nm of tuning would be possible with the film stack considered in this study. These tradeoffs may improve at other wavelengths or with EC materials different than those considered here. Finally, based on our limited investigation and material set

  1. Recycling of metal-organic chemical vapor deposition waste of GaN based power device and LED industry by acidic leaching: Process optimization and kinetics study

    NASA Astrophysics Data System (ADS)

    Swain, Basudev; Mishra, Chinmayee; Kang, Leeseung; Park, Kyung-Soo; Lee, Chan Gi; Hong, Hyun Seon; Park, Jeung-Jin

    2015-05-01

    Recovery of metal values from GaN, a metal-organic chemical vapor deposition (MOCVD) waste of GaN based power device and LED industry is investigated by acidic leaching. Leaching kinetics of gallium rich MOCVD waste is studied and the process is optimized. The gallium rich waste MOCVD dust is characterized by XRD and ICP-AES analysis followed by aqua regia digestion. Different mineral acids are used to find out the best lixiviant for selective leaching of the gallium and indium. Concentrated HCl is relatively better lixiviant having reasonably faster kinetic and better leaching efficiency. Various leaching process parameters like effect of acidity, pulp density, temperature and concentration of catalyst on the leaching efficiency of gallium and indium are investigated. Reasonably, 4 M HCl, a pulp density of 50 g/L, 100 °C and stirring rate of 400 rpm are the effective optimum condition for quantitative leaching of gallium and indium.

  2. Oxide Charge Engineering of Atomic Layer Deposited AlOxNy/Al2O3 Gate Dielectrics: A Path to Enhancement Mode GaN Devices.

    PubMed

    Negara, M A; Kitano, M; Long, R D; McIntyre, P C

    2016-08-17

    Nitrogen incorporation to produce negative fixed charge in Al2O3 gate insulator layers is investigated as a path to achieve enhancement mode GaN device operation. A uniform distribution of nitrogen across the resulting AlOxNy films is obtained using N2 plasma enhanced atomic layer deposition (ALD). The flat band voltage (Vfb) increases to a significantly more positive value with increasing nitrogen concentration. Insertion of a 2 nm thick Al2O3 interlayer greatly decreases the trap density of the insulator/GaN interface, and reduces the voltage hysteresis and frequency dispersion of gate capacitance compared to single-layer AlOxNy gate insulators in GaN MOSCAPs.

  3. Oxide Charge Engineering of Atomic Layer Deposited AlOxNy/Al2O3 Gate Dielectrics: A Path to Enhancement Mode GaN Devices.

    PubMed

    Negara, M A; Kitano, M; Long, R D; McIntyre, P C

    2016-08-17

    Nitrogen incorporation to produce negative fixed charge in Al2O3 gate insulator layers is investigated as a path to achieve enhancement mode GaN device operation. A uniform distribution of nitrogen across the resulting AlOxNy films is obtained using N2 plasma enhanced atomic layer deposition (ALD). The flat band voltage (Vfb) increases to a significantly more positive value with increasing nitrogen concentration. Insertion of a 2 nm thick Al2O3 interlayer greatly decreases the trap density of the insulator/GaN interface, and reduces the voltage hysteresis and frequency dispersion of gate capacitance compared to single-layer AlOxNy gate insulators in GaN MOSCAPs. PMID:27459343

  4. Thin film silicon by a microwave plasma deposition technique: Growth and devices, and, interface effects in amorphous silicon/crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Jagannathan, Basanth

    Thin film silicon (Si) was deposited by a microwave plasma CVD technique, employing double dilution of silane, for the growth of low hydrogen content Si films with a controllable microstructure on amorphous substrates at low temperatures (<400sp°C). The double dilution was achieved by using a Ar (He) carrier for silane and its subsequent dilution by Hsb2. Structural and electrical properties of the films have been investigated over a wide growth space (temperature, power, pressure and dilution). Amorphous Si films deposited by silane diluted in He showed a compact nature and a hydrogen content of ˜8 at.% with a photo/dark conductivity ratio of 10sp4. Thin film transistors (W/L = 500/25) fabricated on these films, showed an on/off ratio of ˜10sp6 and a low threshold voltage of 2.92 volts. Microcrystalline Si films with a high crystalline content (˜80%) were also prepared by this technique. Such films showed a dark conductivity ˜10sp{-6} S/cm, with a conduction activation energy of 0.49 eV. Film growth and properties have been compared for deposition in Ar and He carrier systems and growth models have been proposed. Low temperature junction formation by undoped thin film silicon was examined through a thin film silicon/p-type crystalline silicon heterojunctions. The thin film silicon layers were deposited by rf glow discharge, dc magnetron sputtering and microwave plasma CVD. The hetero-interface was identified by current transport analysis and high frequency capacitance methods as the key parameter controlling the photovoltaic (PV) response. The effect of the interface on the device properties (PV, junction, and carrier transport) was examined with respect to modifications created by chemical treatment, type of plasma species, their energy and film microstructure interacting with the substrate. Thermally stimulated capacitance was used to determine the interfacial trap parameters. Plasma deposition of thin film silicon on chemically clean c-Si created electron

  5. Microstructure and electroluminescent performance of chemical vapor deposited zinc sulfide doped with manganese films for integration in thin film electroluminescent devices

    NASA Astrophysics Data System (ADS)

    Topol, Anna Wanda

    Zinc sulfide (ZnS) doped with manganese (Mn), ZnS:Mn, is widely recognized as the brightest and most effective electroluminescent (EL) phosphor used in current thin film electroluminescent (TFEL) devices. ZnS acts as a host lattice for the luminescent activator, Mn, leading to a highly efficient yellow-orange EL emission, and resulting in a wide array of applications in monochrome, multi-color and full color displays. Although this wide band dap (3.7 eV) material can be prepared by several deposition techniques, the chemical vapor deposition (CVD) is the most promising for TFEL applications in terms of viable deposition rates, high thickness and composition uniformity, and excellent yield over large area panels. This study describes the development and optimization of a CVD ZnS:Mn process using diethylzinc [(C2H5)2Zn, DEZ], di-pi-cyclopentadienylmanganese [(C5H5)2Mn, CPMn], and hydrogen sulfide [H2S] as the chemical sources for, respectively, Zn, Mn, and S. The effects of key deposition parameters on resulting Film microstructure and performance are discussed, primarily in the context of identifying an optimized process window for best electroluminescence behavior. In particular, substrate temperature was observed to play a key role in the formation of high quality crystalline ZnS:Mn films leading to improved brightness and EL efficiency. Further investigations of the influence of temperature treatment on the structural characteristics and EL performance of the CVD ZnS:Mn film were carried out. In this study, the influence of post-deposition annealing both in-situ and ex-situ annealing processes, on chemical, structural, and electroluminescent characteristics of the phosphor layer are described. The material properties of the employed dielectric are among the key factors determining the performance, stability and reliability of the TFEL display and therefore, the choice of dielectric material for use in ACTFEL displays is crucial. In addition, the luminous

  6. Four shades of brown: tuning of electrochromic polymer blends toward high-contrast eyewear.

    PubMed

    Österholm, Anna M; Shen, D Eric; Kerszulis, Justin A; Bulloch, Rayford H; Kuepfert, Michael; Dyer, Aubrey L; Reynolds, John R

    2015-01-28

    We report a straightforward strategy of accessing a wide variety of colors through simple predictive color mixing of electrochromic polymers (ECPs). We have created a set of brown ECP blends that can be incorporated as the active material in user-controlled electrochromic eyewear. Color mixing of ECPs proceeds in a subtractive fashion, and we acquire various hues of brown through the mixing of cyan and yellow primaries in combination with orange and periwinkle-blue secondary colors. Upon oxidation, all of the created blends exhibit a change in transmittance from ca. 10 to 70% in a few seconds. We demonstrate the attractiveness of these ECP blends as active materials in electrochromic eyewear by assembling user-controlled, high-contrast, fast-switching, and fully solution-processable electrochromic lenses with colorless transmissive states and colored states that correspond to commercially available sunglasses. The lenses were fabricated using a combination of inkjet printing and blade-coating to illustrate the feasibility of using soluble ECPs for high-throughput and large-scale processing. PMID:25575379

  7. Four shades of brown: tuning of electrochromic polymer blends toward high-contrast eyewear.

    PubMed

    Österholm, Anna M; Shen, D Eric; Kerszulis, Justin A; Bulloch, Rayford H; Kuepfert, Michael; Dyer, Aubrey L; Reynolds, John R

    2015-01-28

    We report a straightforward strategy of accessing a wide variety of colors through simple predictive color mixing of electrochromic polymers (ECPs). We have created a set of brown ECP blends that can be incorporated as the active material in user-controlled electrochromic eyewear. Color mixing of ECPs proceeds in a subtractive fashion, and we acquire various hues of brown through the mixing of cyan and yellow primaries in combination with orange and periwinkle-blue secondary colors. Upon oxidation, all of the created blends exhibit a change in transmittance from ca. 10 to 70% in a few seconds. We demonstrate the attractiveness of these ECP blends as active materials in electrochromic eyewear by assembling user-controlled, high-contrast, fast-switching, and fully solution-processable electrochromic lenses with colorless transmissive states and colored states that correspond to commercially available sunglasses. The lenses were fabricated using a combination of inkjet printing and blade-coating to illustrate the feasibility of using soluble ECPs for high-throughput and large-scale processing.

  8. Validation of the DIFFAL, HPAC and HotSpot Dispersion Models Using the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials Witness Plate Deposition Dataset.

    PubMed

    Purves, Murray; Parkes, David

    2016-05-01

    Three atmospheric dispersion models--DIFFAL, HPAC, and HotSpot--of differing complexities have been validated against the witness plate deposition dataset taken during the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials. The small-scale nature of these trials in comparison to many other historical radiological dispersion trials provides a unique opportunity to evaluate the near-field performance of the models considered. This paper performs validation of these models using two graphical methods of comparison: deposition contour plots and hotline profile graphs. All of the models tested are assessed to perform well, especially considering that previous model developments and validations have been focused on larger-scale scenarios. Of the models, HPAC generally produced the most accurate results, especially at locations within ∼100 m of GZ. Features present within the observed data, such as hot spots, were not well modeled by any of the codes considered. Additionally, it was found that an increase in the complexity of the meteorological data input to the models did not necessarily lead to an improvement in model accuracy; this is potentially due to the small-scale nature of the trials.

  9. Dynamic expression profiles of MMPs/TIMPs and collagen deposition in mechanically unloaded rat heart: implications for left ventricular assist device support-induced cardiac alterations.

    PubMed

    Wang, Lu; Xu, Yu-Xian; Du, Xiao-Jie; Sun, Quan-Ge; Tian, Ying-Jun

    2013-09-01

    Left ventricular assist devices (LVADs) ameliorate heart failure by reducing preload and afterload. However, extracellular matrix (ECM) deposition after application of LVADs is not clearly defined. The purpose of the present study was to investigate ECM remodeling after mechanical unloading in a rat heart transplant model. Sixty male Lewis rats were subjected to abdominal heterotopic heart transplantation, and the transplanted hearts were pressure- and volume-unloaded. The age- and weight- matched male Lewis rats who had undergone open thoracic surgeries were used as the control. Left ventricle ECM accumulation and the expression/activity of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs) were measured on the third, seventh, and fourteenth days after transplantation/sham surgery. Compared with the control group, myocardial ECM deposition significantly increased on the seventh and fourteenth days after heart transplantation (P < 0.05) and peaked on the 14th day. The gelatinase activity as well as mRNA expression of MMP-2 and MMP-9 significantly increased after transplantation (P < 0.05). Both mRNA and protein levels of TIMP-1 and TIMP-2 significantly increased compared with those of the control group. Mechanical unloading may lead to adverse remodeling of the ECM of the left ventricle. The underlying mechanism may due to the imbalance of the MMP/TIMP system, especially the remarkable upregulation of TIMPs in the pressure and volume unloaded heart.

  10. Study of the feasibility of applying laser-induced breakdown spectroscopy for in-situ characterization of deposited layers in fusion devices

    NASA Astrophysics Data System (ADS)

    Huber, A.; Schweer, B.; Philipps, V.; Leyte-Gonzales, R.; Gierse, N.; Zlobinski, M.; Brezinsek, S.; Kotov, V.; Mertens, P.; Samm, U.; Sergienko, G.

    2011-12-01

    This paper presents a feasibility study of laser-induced breakdown spectroscopy (LIBS) for the development of an in-situ diagnostic for the characterization of deposition layers on plasma-facing components in fusion devices. Preferentially, LIBS would be applied in the presence of a toroidal magnetic field and under high vacuum conditions. The impact of the laser-energy densities on the laser-induced plasma parameters and correspondingly on the number of emitted photons and on the reproducibility of the LIBS method has been studied in laboratory experiments and in TEXTOR on fine-grain graphite (EK98) as well as on bulk W samples coated with carbon and metallic-containing deposits. The effect of magnetic fields and of ambient pressures in the range from 2×10-4 Pa to 10 Pa on the carbon plasma plume produced by the LIBS technique has been studied on TEXTOR between plasma pulses. The possibility of applying this method to ITER is discussed.

  11. Giant dendritic molecular electrochrome batteries with ferrocenyl and pentamethylferrocenyl termini.

    PubMed

    Ornelas, Catia; Ruiz, Jaime; Belin, Colette; Astruc, Didier

    2009-01-21

    Giant redox dendrimers were synthesized with ferrocenyl and pentamethylferrocenyl termini up to a theoretical number of 3(9) tethers (seventh generation). Lengthening of the tethers proved to be a reliable strategy to overcome the bulk constraint at the dendrimers periphery. These redox metallodendrimers were characterized by (1)H, (13)C, and (29)Si NMR; MALDI-TOF mass spectrometry (for the low generations); elemental analysis; UV-vis spectroscopy; dynamic light scattering (DLS); atomic force microscopy (AFM); electron-force microscopy (EFM) for half- or fully oxidized dendrimers; cyclic voltammetry; and coulometry. UV-vis spectroscopy, coulometry, and analytical data are consistent with an increasing amount of defects as the generation number increases, with this amount remaining relatively weak up to G(5). AFM shows that the dendrimers form aggregates of discrete size on the mica surface, recalling the agglomeration of metal atoms in monodisperse nanoparticles. Cyclic voltammetry reveals full chemical and electrochemical reversibility up to G(7), showing that electron transfer is fast among the flexible peripheral redox sites. Indeed, the redox stability of these new electrochromic dendrimers, i.e., a battery behavior, was established by complete chemical oxido-reduction cycles, and the blue 17-electron ferrocenium and deep-green mixed-valence Fe(III)/Fe(II) dendritic complexes were isolated and characterized. AFM studies also show the reversible dendrimer size changes from upon redox switching between Fe(II) and Fe(III), suggesting a breathing mechanism controlled by the redox potential. Considerable adsorption of high-generation dendrimers on Pt electrodes such as G(7)-Fc allows the easy formation of modified electrodes that sense the ATP anion only involving the electrostatic factor even in the absence of any other type of interaction with the redox tethers.

  12. Conformal Coating of Three-Dimensional Nanostructures via Atomic Layer Deposition for Development of Advanced Energy Storage Devices and Plasmonic Transparent Conductors

    NASA Astrophysics Data System (ADS)

    Malek, Gary A.

    Due to the prodigious amount of electrical energy consumed throughout the world, there exists a great demand for new and improved methods of generating electrical energy in a clean and renewable manner as well as finding more effective ways to store it. This enormous task is of great interest to scientists and engineers, and much headway is being made by utilizing three-dimensional (3D) nanostructured materials. This work explores the application of two types of 3D nanostructured materials toward fabrication of advanced electrical energy storage and conversion devices. The first nanostructured material consists of vertically aligned carbon nanofibers. This three-dimensional structure is opaque, electrically conducting, and contains active sites along the outside of each fiber that are conducive to chemical reactions. Therefore, they make the perfect 3D conducting nanostructured substrate for advanced energy storage devices. In this work, the details for transforming vertically aligned carbon nanofiber arrays into core-shell structures via atomic layer deposition as well as into a mesoporous manganese oxide coated supercapacitor electrode are given. Another unique type of three-dimensional nanostructured substrate is nanotextured glass, which is transparent but non-conducting. Therefore, it can be converted to a 3D transparent conductor for possible application in photovoltaics if it can be conformally coated with a conducting material. This work details that transformation as well as the addition of plasmonic gold nanoparticles to complete the transition to a 3D plasmonic transparent conductor.

  13. Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process.

    PubMed

    Swain, Basudev; Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo; Lee, Kun-Jae

    2015-07-01

    Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga0.97N0.9O0.09 is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga0.97N0.9O0.09 of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4M HCl, 100°C and pulp density of 100 kg/m(3,) respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition.

  14. Opto-structural, electrical and electrochromic properties of crystalline nickel oxide thin films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Mahmoud, S. A.; Akl, A. A.; Kamal, H.; Abdel-Hady, K.

    2002-02-01

    Polycrystalline nickel oxide films with preferential growth along (1 1 1) plane were deposited onto glass substrates, maintained at 350°C, by the spray pyrolysis technique using nickel chloride as starting solution. The effect of solution concentration on their structural, electrical, and optical properties was studied. Using X-ray diffraction, the structural characteristics have been studied and due to the high degree of preferred orientation, Voigt analysis of single reflection was used to determine the microstructural properties (crystallite size and microstrain). The refractive index n and the extinction coefficient k have been computed from the corrected transmittance and reflectance measurements over the spectral range 300-2400 nm. Analysis of the absorption versus photon energy curves revealed a direct transition with optical band gap, Eg, of 3.6 eV and indirect transition within the range 3.97-3.75 eV as solution molarity increases from 0.05 to 0.3 M. The electrochromic behaviour of polycrystalline nickel oxide film were investigated by means of cyclic voltametry in 1 M KOH aqueous solution. Cycling showed significant increase in solar optical modulation reaching a value of 0.23 after 150 cycles.

  15. Effect of tungsten on the electrochromic behaviour of sol-gel dip coated molybdenum oxide thin films

    SciTech Connect

    Dhanasankar, M.; Purushothaman, K.K.; Muralidharan, G.

    2010-05-15

    The paper describes the results obtained on the performance of Mo oxide and mixed W/Mo oxide thin films for possible electrochromic applications. Mo and W/Mo oxide films were deposited on conductive (FTO) glass substrates using sol-gel dip coating method. The films were annealed at 250 {sup o}C for 30 min. The structure and morphology of Mo and W/Mo oxide films were examined using XRD, SEM and EDS. XRD results indicate the amorphous nature of the Mo and W/Mo oxide films annealed for 30 min. The CV measurements revealed that the films prepared with 10 wt.% of tungsten exhibit maximum anodic/cathodic diffusion coefficient of 24.99/12.71 x 10{sup -11} cm{sup 2}/s. The same film exhibits a maximum transmittance variation ({Delta}T%) of 83.4% at 630 nm and 81.06% at 550 nm with the optical density of 1.00 and 1.13 respectively.

  16. Roll-to-Roll sputtered ITO/Cu/ITO multilayer electrode for flexible, transparent thin film heaters and electrochromic applications

    PubMed Central

    Park, Sung-Hyun; Lee, Sang-Mok; Ko, Eun-Hye; Kim, Tae-Ho; Nah, Yoon-Chae; Lee, Sang-Jin; Lee, Jae Heung; Kim, Han-Ki

    2016-01-01

    We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows. PMID:27653830

  17. Thermal MEMS actuator operation in aqueous media/seawater: Performance enhancement through atomic layer deposition post processing of PolyMUMPs devices

    SciTech Connect

    Warnat, Stephan Forbrigger, Cameron; Hubbard, Ted; Bertuch, Adam; Sundaram, Ganesh

    2015-01-15

    A method to enhance thermal microelectromechanical systems (MEMS) actuators in aqueous media by using dielectric encapsulation layers is presented. Aqueous media reduces the available mechanical energy of the thermal actuator through an electrical short between actuator structures. Al{sub 2}O{sub 3} and TiO{sub 2} laminates with various thicknesses were deposited on packaged PolyMUMPs devices to electrically separate the actuator from the aqueous media. Atomic layer deposition was used to form an encapsulation layer around released MEMS structures and the package. The enhancement was assessed by the increase of the elastic energy, which is proportional to the mechanical stiffness of the actuator and the displacement squared. The mechanical stiffness of the encapsulated actuators compared with the noncoated actuators was increased by factors ranging from 1.45 (for 45 nm Al{sub 2}O{sub 3} + 20 nm TiO{sub 2}) to 1.87 (for 90 nm Al{sub 2}O{sub 3} + 40 nm TiO{sub 2}). Displacement measurements were made for all laminate combinations in filtered tap water and seawater by using FFT based displacement measurement technique with a repeatability of ∼10 nm. For all laminate structures, the elastic energy increased and enhanced the actuator performance: In seawater, the mechanical output energy increased by factors ranging from 5 (for 90 nm Al{sub 2}O{sub 3}) to 11 (for 90 nm Al{sub 2}O{sub 3} + 40 nm TiO{sub 2}). The authors also measured the long-term actuator stability/reliability in seawater. Samples were stored for 29 days in seawater and tested for 17 days in seawater. Laminates with TiO{sub 2} layers allowed constant operation over the entire measurement period.

  18. Absorption and electrochromic modulation of near-infrared light: realized by tungsten suboxide

    NASA Astrophysics Data System (ADS)

    Li, Guilian; Zhang, Shouhao; Guo, Chongshen; Liu, Shaoqin

    2016-05-01

    In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured architectures of the W18O49 nanocrystal electrochromic films exhibit high contrast, faster switching response, higher coloration efficiencies (150 cm2 C-1 at 650 nm and 255 cm2 C-1 at 1300 nm), better long-term redox switching stability (reversibility of 98% after 500 cycles) and wide electrochromic spectrum coverage of both the visible and infrared regions.In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured

  19. Control of metamorphic buffer structure and device performance of In(x)Ga(1-x)As epitaxial layers fabricated by metal organic chemical vapor deposition.

    PubMed

    Nguyen, H Q; Yu, H W; Luc, Q H; Tang, Y Z; Phan, V T H; Hsu, C H; Chang, E Y; Tseng, Y C

    2014-12-01

    Using a step-graded (SG) buffer structure via metal-organic chemical vapor deposition, we demonstrate a high suitability of In0.5Ga0.5As epitaxial layers on a GaAs substrate for electronic device application. Taking advantage of the technique's precise control, we were able to increase the number of SG layers to achieve a fairly low dislocation density (∼10(6) cm(-2)), while keeping each individual SG layer slightly exceeding the critical thickness (∼80 nm) for strain relaxation. This met the demanded but contradictory requirements, and even offered excellent scalability by lowering the whole buffer structure down to 2.3 μm. This scalability overwhelmingly excels the forefront studies. The effects of the SG misfit strain on the crystal quality and surface morphology of In0.5Ga0.5As epitaxial layers were carefully investigated, and were correlated to threading dislocation (TD) blocking mechanisms. From microstructural analyses, TDs can be blocked effectively through self-annihilation reactions, or hindered randomly by misfit dislocation mechanisms. Growth conditions for avoiding phase separation were also explored and identified. The buffer-improved, high-quality In0.5Ga0.5As epitaxial layers enabled a high-performance, metal-oxide-semiconductor capacitor on a GaAs substrate. The devices displayed remarkable capacitance-voltage responses with small frequency dispersion. A promising interface trap density of 3 × 10(12) eV(-1) cm(-2) in a conductance test was also obtained. These electrical performances are competitive to those using lattice-coherent but pricey InGaAs/InP systems.

  20. Corrosion and ion release behavior of Cu/Ti film prepared via physical vapor deposition in vitro as potential biomaterials for cardiovascular devices

    NASA Astrophysics Data System (ADS)

    Liu, Hengquan; Zhang, Deyuan; Shen, Feng; Zhang, Gui; Song, Shenhua

    2012-07-01

    Cu/Ti films of various Cu/Ti ratios were prepared on a TiNi alloy via vacuum arc plasma deposition. The phase composition, structure, and concentration of elements were investigated via X-ray diffraction and X-photoelectron energy spectrum. The hemolysis ratio and platelet adhesion of the different films were characterized to evaluate blood compatibility. The corrosion and ion release behavior were investigated via a typical immersion test and electrochemical method. The growth of endothelial cells (ECs) was investigated, and methylthiazolyte-trazolium method was employed to evaluate the effect of Cu2+. The sophisticated films showed good compatibility. However, with increasing quality ratio of Cu/Ti, the hemolysis ratio increased, and some platelets started to break slightly. The Cu2+ release was gradually stabilized. The open circuit potential of the Cu/Ti film-modified samples was lower than that of the TiNi substrate. The polarization test result indicates that the passivation stability performance of Cu/Ti film samples is less than the TiNi substrate, and is favorable to Cu2+ release. The adhesion and proliferation of ECs would be inhibited with 10 wt.% Cu concentration of the film, and ECs would undergo apoptosis at >50 wt.% concentration. A Cu/Ti film with good compatibility and anti-endothelialization has potential applications for special cardiovascular devices.

  1. Ultraviolet photoconductive devices with an n-GaN nanorod-graphene hybrid structure synthesized by metal-organic chemical vapor deposition

    PubMed Central

    Kang, San; Mandal, Arjun; Chu, Jae Hwan; Park, Ji-Hyeon; Kwon, Soon-Yong; Lee, Cheul-Ro

    2015-01-01

    The superior photoconductive behavior of a simple, cost-effective n-GaN nanorod (NR)-graphene hybrid device structure is demonstrated for the first time. The proposed hybrid structure was synthesized on a Si (111) substrate using the high-quality graphene transfer method and the relatively low-temperature metal-organic chemical vapor deposition (MOCVD) process with a high V/III ratio to protect the graphene layer from thermal damage during the growth of n-GaN nanorods. Defect-free n-GaN NRs were grown on a highly ordered graphene monolayer on Si without forming any metal-catalyst or droplet seeds. The prominent existence of the undamaged monolayer graphene even after the growth of highly dense n-GaN NRs, as determined using Raman spectroscopy and high-resolution transmission electron microscopy (HR-TEM), facilitated the excellent transport of the generated charge carriers through the photoconductive channel. The highly matched n-GaN NR-graphene hybrid structure exhibited enhancement in the photocurrent along with increased sensitivity and photoresponsivity, which were attributed to the extremely low carrier trap density in the photoconductive channel. PMID:26028318

  2. Device performances of organic light-emitting diodes with indium tin oxide, gallium zinc oxide, and indium zinc tin oxide anodes deposited at room temperature.

    PubMed

    Lee, Changhun; Ko, Yoonduk; Kim, Youngsung

    2013-12-01

    Thin films of Indium tin oxide (ITO), Gallium zinc oxide (GZO), and Indium zinc tin oxide (IZTO) were deposited on glass substrates by pulsed direct current magnetron sputtering at room temperature. The structural, optical, and electrical properties of the films were investigated towards evaluating their applications as flexible anodes. IZTO films exhibited the lowest resistivity (6.3 x 10(-4) Omega cm). Organic light-emitting diodes (OLEDs) were fabricated using the ITO, GZO, and IZTO films as anode layers. The turn-on voltages at a current density of 4.5 mA/cm2, 5.5 mA/cm2, 6.5 mA/cm2 were 5.5 V, 13.7 V, and 4.7 V for the devices with ITO, GZO, and IZTO anodes, respectively. The best performance was observed with the IZTO film, indicating its suitability as an alternative material for conventional ITO anodes used in OLEDs and flexible displays. PMID:24266182

  3. Field Evaluation of the Explosive Deposition of Cesium on Concrete Surfaces Following the Detonation of a Mock Radiological Dispersal Device (RDD)

    SciTech Connect

    Gates-Anderson, D D; Fisher, R; Sutton, M; Rasmussen, C; Viani, B; McNab, W; Gray, J; Hu, Q

    2006-11-10

    Researchers at Lawrence Livermore National Laboratory conducted a field study to evaluate the deposition of an explosively dispersed radionuclide surrogate (CsCl) on grime and non-grime containing urban surfaces. An additional objective of this study was to evaluate several laboratory surface contamination techniques for the preparation of mock urban surfaces in order to determine the method that most closely mimics surface contamination following an RDD event. The field study was conducted at the LLNL Site 300 Contained Firing Facility (CFF). For our study, we detonated a mock RDD made using C4 and non-radioactive CsCl. Lab prepared concrete samples (3.8 cm x 7.6 cm cylinders) were made using 4 different conditioning regimes to mimic a range of conditions that may be encountered during an RDD event. This sample set included dry, wet, carbonated and non-carbonated cores with and without the application of urban grime. In addition, concreted samples (13 cm x 13 cm x 5 cm) removed from an urban surface were placed inside the CFF chamber. The samples were placed inside the firing chamber at 3 different distances from the mock RDD device. Following the detonation of the mock RDD, the samples were removed from the firing chamber and selected cores were characterized by laser ablation and scanning electron microscopy. Preliminary results suggest that Cs migrates into the concrete samples and the presence of a grime layer does not appear to impede this migration.

  4. Resistive switching and synaptic properties of fully atomic layer deposition grown TiN/HfO2/TiN devices

    NASA Astrophysics Data System (ADS)

    Matveyev, Yu.; Egorov, K.; Markeev, A.; Zenkevich, A.

    2015-01-01

    Recently proposed novel neural network hardware designs imply the use of memristors as electronic synapses in 3D cross-bar architecture. Atomic layer deposition (ALD) is the most feasible technique to fabricate such arrays. In this work, we present the results of the detailed investigation of the gradual resistive switching (memristive) effect in nanometer thick fully ALD grown TiN/HfO2/TiN stacks. The modelling of the I-V curves confirms interface limited trap-assisted-tunneling mechanism along the oxygen vacancies in HfO2 in all conduction states. The resistivity of the stack is found to critically depend upon the distance from the interface to the first trap in HfO2. The memristive properties of ALD grown TiN/HfO2/TiN devices are correlated with the demonstrated neuromorphic functionalities, such as long-term potentiation/depression and spike-timing dependent plasticity, thus indicating their potential as electronic synapses in neuromorphic hardware.

  5. Resistive switching and synaptic properties of fully atomic layer deposition grown TiN/HfO{sub 2}/TiN devices

    SciTech Connect

    Matveyev, Yu.; Zenkevich, A.; Egorov, K.; Markeev, A.

    2015-01-28

    Recently proposed novel neural network hardware designs imply the use of memristors as electronic synapses in 3D cross-bar architecture. Atomic layer deposition (ALD) is the most feasible technique to fabricate such arrays. In this work, we present the results of the detailed investigation of the gradual resistive switching (memristive) effect in nanometer thick fully ALD grown TiN/HfO{sub 2}/TiN stacks. The modelling of the I-V curves confirms interface limited trap-assisted-tunneling mechanism along the oxygen vacancies in HfO{sub 2} in all conduction states. The resistivity of the stack is found to critically depend upon the distance from the interface to the first trap in HfO{sub 2}. The memristive properties of ALD grown TiN/HfO{sub 2}/TiN devices are correlated with the demonstrated neuromorphic functionalities, such as long-term potentiation/depression and spike-timing dependent plasticity, thus indicating their potential as electronic synapses in neuromorphic hardware.

  6. Ultraviolet photoconductive devices with an n-GaN nanorod-graphene hybrid structure synthesized by metal-organic chemical vapor deposition.

    PubMed

    Kang, San; Mandal, Arjun; Chu, Jae Hwan; Park, Ji-Hyeon; Kwon, Soon-Yong; Lee, Cheul-Ro

    2015-06-01

    The superior photoconductive behavior of a simple, cost-effective n-GaN nanorod (NR)-graphene hybrid device structure is demonstrated for the first time. The proposed hybrid structure was synthesized on a Si (111) substrate using the high-quality graphene transfer method and the relatively low-temperature metal-organic chemical vapor deposition (MOCVD) process with a high V/III ratio to protect the graphene layer from thermal damage during the growth of n-GaN nanorods. Defect-free n-GaN NRs were grown on a highly ordered graphene monolayer on Si without forming any metal-catalyst or droplet seeds. The prominent existence of the undamaged monolayer graphene even after the growth of highly dense n-GaN NRs, as determined using Raman spectroscopy and high-resolution transmission electron microscopy (HR-TEM), facilitated the excellent transport of the generated charge carriers through the photoconductive channel. The highly matched n-GaN NR-graphene hybrid structure exhibited enhancement in the photocurrent along with increased sensitivity and photoresponsivity, which were attributed to the extremely low carrier trap density in the photoconductive channel.

  7. Investigation of x-ray photoelectron spectroscopic (XPS), cyclic voltammetric analyses of WO3 films and their electrochromic response in FTO/WO3/electrolyte/FTO cells

    NASA Astrophysics Data System (ADS)

    Sivakumar, R.; Gopalakrishnan, R.; Jayachandran, M.; Sanjeeviraja, C.

    2006-06-01

    Electrochromic thin films of tungsten oxide (WO3) were prepared on transparent conducting oxide substrates, i.e., fluorine doped tin oxide coated (FTO or SnO2:F) glass and microscopic glass substrates by the electron beam evaporation technique using pure WO3 (99.99%) pellets at various substrate temperatures (i.e., Tsub = room temperature (RT, 30 °C), 100 °C and 200 °C). The films were prepared under vacuum of the order of 1 × 10-5 mbar. The room temperature prepared films were further post-heat-treated (Tanne) at 200 and 300 °C for about 1 h in the vacuum environment. The prepared films are in monoclinic phase. The chemical composition has been characterized by using the XPS technique. The W 4f and O 1s core levels of WO3 films have been studied on the samples. The obtained core level binding energies revealed the WO3 films contained six-valent tungsten (W6+). The electrochemical nature of the films was studied by a three-electrode electrochemical cell in the configuration of FTO/WO3/H2SO4/Pt, SCE, using the cyclic voltammetry (CV) technique. Electrochromic devices (ECDs) of the general type FTO/WO3/electrolyte/FTO were studied. The films produced at higher substrate temperature show smaller modulation of the visible spectrum, compared with the films produced at lower temperatures. The significant chemical bonding nature associated with the coloring/bleaching process which follows the H+ ion incorporation in the film is studied by FTIR analysis. The W-O-W framework peak was observed at 563 cm-1 and confirms the stability of the films in the electrochemical analysis. The results obtained from cyclic voltammetry technique and ECD cell characterization are used to emphasize the suitability for some applications of the solar control systems.

  8. The Impact of Overhang Design on the Performance of ElectrochromicWindows

    SciTech Connect

    Tavil, Aslihan; Lee, Eleanor S.

    2005-08-01

    In this study, various facade designs with overhangs combined with electrochromic window control strategies were modeled with a prototypical commercial office building in a hot and cold climate using the DOE 2.1E building energy simulation program. Annual total energy use (ATE), peak electric demand (PED), average daylight illuminance (DI), and daylight glare index (DGI) were computed and compared to determine which combinations of fagade design and control strategies yielded the greatest energy efficiency, daylight amenity, and visual comfort.

  9. The energy-savings potential of electrochromic windows in the UScommercial buildings sector

    SciTech Connect

    Lee, Eleanor; Yazdanian, Mehry; Selkowitz, Stephen

    2004-04-30

    Switchable electrochromic (EC) windows have been projected to significantly reduce the energy use of buildings nationwide. This study quantifies the potential impact of electrochromic windows on US primary energy use in the commercial building sector and also provides a broader database of energy use and peak demand savings for perimeter zones than that given in previous LBNL simulation studies. The DOE-2.1E building simulation program was used to predict the annual energy use of a three-story prototypical commercial office building located in five US climates and 16 California climate zones. The energy performance of an electrochromic window controlled to maintain daylight illuminance at a prescribed setpoint level is compared to conventional and the best available commercial windows as well as windows defined by the ASHRAE 90.1-1999 and California Title 24-2005 Prescriptive Standards. Perimeter zone energy use and peak demand savings data by orientation, window size, and climate are given for windows with interior shading, attached shading, and horizon obstructions (to simulate an urban environment). Perimeter zone primary energy use is reduced by 10-20% in east, south, and west zones in most climates if the commercial building has a large window-to-wall area ratio of 0.60 compared to a spectrally selective low-e window with daylighting controls and no interior or exterior shading. Peak demand for the same condition is reduced by 20-30%. The emerging electrochromic window with daylighting controls is projected to save approximately 91.5-97.3 10{sup 12} Btu in the year 2030 compared to a spectrally selective low-E window with manually-controlled interior shades and no daylighting controls if it reaches a 40% market penetration level in that year.

  10. Absorption and electrochromic modulation of near-infrared light: realized by tungsten suboxide.

    PubMed

    Li, Guilian; Zhang, Shouhao; Guo, Chongshen; Liu, Shaoqin

    2016-05-01

    In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured architectures of the W18O49 nanocrystal electrochromic films exhibit high contrast, faster switching response, higher coloration efficiencies (150 cm(2) C(-1) at 650 nm and 255 cm(2) C(-1) at 1300 nm), better long-term redox switching stability (reversibility of 98% after 500 cycles) and wide electrochromic spectrum coverage of both the visible and infrared regions. PMID:27119556

  11. Absorption and electrochromic modulation of near-infrared light: realized by tungsten suboxide.

    PubMed

    Li, Guilian; Zhang, Shouhao; Guo, Chongshen; Liu, Shaoqin

    2016-05-01

    In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured architectures of the W18O49 nanocrystal electrochromic films exhibit high contrast, faster switching response, higher coloration efficiencies (150 cm(2) C(-1) at 650 nm and 255 cm(2) C(-1) at 1300 nm), better long-term redox switching stability (reversibility of 98% after 500 cycles) and wide electrochromic spectrum coverage of both the visible and infrared regions.

  12. Self-powered biosensor for ascorbic acid with a Prussian blue electrochromic display.

    PubMed

    Zloczewska, Adrianna; Celebanska, Anna; Szot, Katarzyna; Tomaszewska, Dorota; Opallo, Marcin; Jönsson-Niedziolka, Martin

    2014-04-15

    We report on the development of a nanocarbon based anode for sensing of ascorbic acid (AA). The oxidation of AA on this anode occurs at a quite low overpotential which enables the anode to be connected to a biocathode to form an ascorbic acid/O2 biofuel cell that functions as a self-powered biosensor. In conjunction with a Prussian blue electrochromic display the anode can also work as a truly self-powered sensor. The oxidation of ascorbic acid at the anode leads to a reduction of the Prussian blue in the display. The reduced form of Prussian blue, called Prussian white, is transparent. The rate of change from blue to colourless is dependent on the concentration of ascorbic acid. The display can easily be regenerated by connecting it to the biocathode which returns the Prussian blue to its oxidized form. In this way we have created the first self-powered electrochromic sensor that gives quantitative information about the analyte concentration. This is demonstrated by measuring the concentration of ascorbic acid in orange juice. The reported quantitative read-out electrochromic display can serve as a template for the creation of cheap, miniturizable sensors for other relevant analytes.

  13. Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process

    SciTech Connect

    Swain, Basudev; Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo; Lee, Kun-Jae

    2015-07-15

    Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga{sub 0.97}N{sub 0.9}O{sub 0.09} is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga{sub 0.97}N{sub 0.9}O{sub 0.09} of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4 M HCl, 100 °C and pulp density of 100 kg/m{sup 3,} respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition. - Highlights: • Waste MOCVD dust is treated through mechanochemical leaching. • GaN is hardly leached, and converted to NaGaO{sub 2} through ball milling and annealing. • Process for gallium recovery from waste MOCVD dust has been developed. • Thermal analysis and phase properties of GaN to Ga{sub 2}O{sub 3} and GaN to NaGaO{sub 2} is revealed. • Solid-state chemistry involved in this process is reported.

  14. Chemical vapor deposition and atomic layer deposition of metal oxide and nitride thin films

    NASA Astrophysics Data System (ADS)

    Barton, Jeffrey Thomas

    copper layers to wet these surfaces was also investigated. Electrochromic materials are being developed for use in energy-conserving "smart windows" that can control light transmission by varying the voltage across the layer Electrochromic tungsten oxide was deposited from the reaction of tungsten pentacarbonyl alkylisonitriles with oxygen gas. Fluorine-doped tin oxide is a well known transparent conducting oxide (TCO), and zinc stannate has shown promise as a useful TCO with potentially high carrier mobility. A method for depositing fluorine-doped tin oxide from a single-source precursor, dimethyltin-bis-(1,1,1-trifluoro-2,4-hexanedionate), and oxygen gas is presented. Zinc stannate was also deposited by CVD, using zinc acetylacetonate and dibutyltin-bis-(acetylacetonate) and oxygen gas.

  15. Silicon source for vacuum deposition

    NASA Technical Reports Server (NTRS)

    Racette, G. W.; Rutecki, D. J.

    1979-01-01

    Device using two independent silicon sources for ultra-high-vacuum deposition on large substrates can deposit P and N types of silicon simultaneously. Efficient water cooled copper shield supports and cools structure and isolates two filaments.

  16. Structural and optical properties of sol-gel deposited proton conducting Ta{sub 2}O{sub 5} films

    SciTech Connect

    Ozer, N.; Lampert, C.M.

    1995-08-01

    Proton conducting tantalum oxide films were deposited by spin coating using a sol-gel process. The coating solutions were prepared using Ta(OC{sub 2}H{sub 5}){sub 5} as a precursor. X-ray diffraction studies determined that the sol-gel films, heat treated at temperatures below 400 C, were amorphous. Films heat treated at higher temperatures were crystalline Ta{sub 2}O{sub 5}. The solar transmission values (T{sub s}) of tantala films on glass generally range from 0.8--0.9 depending on thickness. The refractive index and the extinction coefficient were evaluated from transmittance characteristics in the UV-VIS-NIR regions. The refractive index values calculated at 550 nm increased from 1.78 to 1.97 with increasing heat treatment from 150 to 450 C. The films heat treated at different temperatures showed low absorption with extinction coefficients of less than k=1x10{sup -3} in the visible range. Spectrophotometric and impedance spectroscopic investigations performed on Ta{sub 2}O{sub 5} films revealed that these films have protonic conductivity of 3.2x10{sup -6} S/cm. The films are suitable for proton conducting layers in electrochromic (EC) devices.

  17. [Devic disease].

    PubMed

    Papeix, Caroline

    2006-11-01

    Devic disease, also known as neuromyelitis optica, is a severe rare condition characterized clinically by one or more episodes of optical neuritis and myelitis. Pathologically, it is characterized by extensive demyelination associated with axon loss and deposits of complement and immunoglobulins (IgM) within the lesions. Specific antibodies for this disease (IgG NMO) were recently identified. Immunosuppressive treatment is currently the best option for preventing relapse. PMID:17086129

  18. Nanocomposite Architecture for Rapid, Spectrally-Selective Electrochromic Modulation of Solar Transmittance.

    PubMed

    Kim, Jongwook; Ong, Gary K; Wang, Yang; LeBlanc, Gabriel; Williams, Teresa E; Mattox, Tracy M; Helms, Brett A; Milliron, Delia J

    2015-08-12

    Two active electrochromic materials, vacancy-doped tungsten oxide (WO(3-x)) nanocrystals and amorphous niobium oxide (NbOx) glass are arranged into a mesostructured architecture. In a strategy applicable across electrochemical applications, the critical dimensions and interfacial connections in the nanocomposite are designed to optimize pathways for electrochemical charging and discharging. The result is an unprecedented optical range for modulation of visible and near-infrared solar radiation with rapid switching kinetics that indicate the WO(3-x) nanocrystal framework effectively pumps charge out of the normally sluggish NbOx glass. The material is durable for at least 2000 electrochemical cycles. PMID:26189324

  19. Electrode with transparent series resistance for uniform switching of optical modulation devices

    DOEpatents

    Tench, D. Morgan; Cunningham, Michael A.; Kobrin, Paul H.

    2008-01-08

    Switching uniformity of an optical modulation device for controlling the propagation of electromagnetic radiation is improved by use of an electrode comprising an electrically resistive layer that is transparent to the radiation. The resistive layer is preferably an innerlayer of a wide-bandgap oxide sandwiched between layers of indium tin oxide or another transparent conductor, and may be of uniform thickness, or may be graded so as to provide further improvement in the switching uniformity. The electrode may be used with electrochromic and reversible electrochemical mirror (REM) smart window devices, as well as display devices based on various technologies.

  20. Buried Anode Device Development: Cooperative Research and Development Final Report, CRADA Number CRD-11-451

    SciTech Connect

    Tenent, R.

    2015-03-01

    The possibility of a reflecting electrochromic device is very attractive, and the 'Buried Anode' architecture developed at NREL could yield such a device. The subject of this cooperative agreement will be the development and refinement of a Buried Anode device process. This development will require the active involvement of NREL and US e-Chromic personnel, and will require the use of NREL equipment as much as possible. When this effort is concluded, US e-Chromic will have enough information to construct a pilot production line, where further development can continue.

  1. Electrochromic Window Demonstration at the Donna Land Port of Entry

    SciTech Connect

    Fernandes, Luis L.; Lee, Eleanor S.; Thanachareonkit, Anothai

    2015-05-01

    The U.S. General Services Administration (GSA) Public Buildings Service (PBS) has jurisdiction, custody or control over 105 land ports of entry throughout the United States, 35 of which are located along the southern border. At these facilities, one of the critical functions of windows is to provide border control personnel with direct visual contact with the surrounding environment. This also can be done through surveillance cameras, but the high value that U.S. Customs and Border Protection (CPB) officers place on direct visual contact can be encapsulated in the following statement by a senior officer regarding this project: “nothing replaces line of sight.” In sunny conditions, however, outdoor visibility can be severely compromised by glare, especially when the orb of the sun is in the field of view. This often leads to the deployment of operable shading devices, such as Venetian blinds. While these devices address the glare, they obstruct the view of the surroundings, negating the visual security benefits of the windows.

  2. Correlation of electrochromic properties and oxidation states in nanocrystalline tungsten trioxide.

    PubMed

    Darmawi, S; Burkhardt, S; Leichtweiss, T; Weber, D A; Wenzel, S; Janek, J; Elm, M T; Klar, P J

    2015-06-28

    Although tungsten trioxide (WO3) has been extensively studied since its electrochromic properties were first discovered, the mechanism responsible for the coloration or bleaching effect is still disputed. New insights into the coloration mechanism of electrochromic, nanocrystalline WO3 are provided in this paper by studying thin WO3 films combining the electrochemical and spectroscopic techniques. By employing in situ UV-Vis transmission spectroscopy at a fixed spectral band pass during electrochemical experiments, such as cyclic voltammetry, a two-step insertion process for both protons and lithium ions is identified, of which one step exhibits a significantly higher coloration efficiency than the other. To obtain a better understanding of the insertion process AxWO3 (A = H, Li,…) thin films were studied at different stages of intercalation using UV-Vis and X-ray photoelectron spectroscopy. The results show that the first step of the intercalation process represents the reduction from initial W(6+) to W(5+) and the second step the reduction of W(5+) to W(4+). We found that the blue coloration of this nanocrystalline tungsten trioxide is mainly due to the presence of W(4+) rather than that of W(5+). PMID:26018838

  3. An electrochromic painter's palette: color mixing via solution co-processing.

    PubMed

    Bulloch, Rayford H; Kerszulis, Justin A; Dyer, Aubrey L; Reynolds, John R

    2015-01-28

    Electrochromic polymers (ECPs) have been shown to be synthetically tunable, producing a full palette of vibrantly colored to highly transmissive polymers. The development of these colored-to-transmissive ECPs employed synthetic design strategies for broad color targeting; however, due to the subtleties of color perception and the intricacies of polymer structure and color relationships, fine color control is difficult. In contrast, color mixing is a well-established practice in the printing industry. We have identified three colored-to-transmissive switching electrochromic polymers, referred to as ECP-Cyan (ECP-C), ECP-Magenta (ECP-M), and ECP-Yellow (ECP-Y), which, via the co-processing of multicomponent ECP mixtures, follow the CMY color mixing model. The presented work qualitatively assesses the thin film characteristics of solution co-processed ECP mixtures. To quantitatively determine the predictability of the color properties of ECP mixtures, we estimated mass extinction coefficients (εmass) from solution spectra of the CMY ECPs and compared the estimated and experimentally observed color values of blends via a calculated color difference (ΔEab). The values of ΔEab range from 8 to 26 across all mixture compositions, with an average value of 15, representing a reasonable degree of agreement between predicted and observed color values. We demonstrate here the ability to co-process ECP mixtures into vibrantly colored, visually continuous films and the ability to estimate the color properties produced in these mixed ECP films.

  4. Nanobrick-like WO3 thin films: Hydrothermal synthesis and electrochromic application

    NASA Astrophysics Data System (ADS)

    Kondalkar, V. V.; Kharade, R. R.; Mali, S. S.; Mane, R. M.; Patil, P. B.; Patil, P. S.; Choudhury, S.; Bhosale, P. N.

    2014-09-01

    Nanobrick-like WO3 thin films have been synthesized via facile hydrothermal route. Nanostructured WO3 thin films were characterized using X-ray diffraction (XRD), UV-Vis-NIR spectrophotometer, scanning electron microscopy (SEM), atomic force microscopy (AFM) to investigate the intentional properties such as phase structure, optical properties and surface morphology. Moreover electrochromic (EC) performance of WO3 thin film was investigated in 0.5 M LiClO4/PC by means of cyclic voltammetry (CV), chronocoulometry (CC) and chronoamperometry (CA). The value of diffusion coefficient (D) was determined from anodic peak current and was found to be 1.51 × 10-9 cm2/s. The response time of 6.9 s for bleaching (tb) and 9.7 s for coloration (tc) was observed with excellent reversibility 76%. The coloration efficiency for nanobricks WO3 is 39.24 cm2/C. CIE 1931 L∗ab values for colored and bleached films were estimated at 2° observer using D-65 illumination. The electrochromic studies show highly reversible and the stable nature of WO3 thin film which provides a versatile and promising application towards the fabrication of smart windows.

  5. Electron cyclotron resonance deposition of amorphous silicon alloy films and devices. Final subcontract report, 1 April 1991--31 March 1992

    SciTech Connect

    Shing, Y.H.

    1992-10-01

    This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of solar cell performance. ECR growth parameters were systematically and extensively investigated; materials characterization included constant photocurrent measurement (CPM), junction capacitance, drive-level capacitance profiling (DLCP), optical transmission, light and dark photoconductivity, and small-angle X-ray scattering (SAXS). Conventional ECR-deposited a-Si:H was compared to a new form, a-Si:(Xe, H), in which xenon gas was added to the ECR plasma. a-Si:(Xe,H) possessed low, stable dark conductivities and high photosensitivites. Light-soaking revealed photodegradation rates about 35% lower than those of comparable radio frequency (rf)-deposited material. ECR-deposited p-type a SiC:H and intrinsic a-Si:H films underwent evaluation as components of p-i-n solar cells with standard rf films for the remaining layers.

  6. Electrochromic behavior of W(x)Si(y)O(z) thin films prepared by reactive magnetron sputtering at normal and glancing angles.

    PubMed

    Gil-Rostra, Jorge; Cano, Manuel; Pedrosa, José M; Ferrer, Francisco Javier; García-García, Francisco; Yubero, Francisco; González-Elipe, Agustín R

    2012-02-01

    This work reports the synthesis at room temperature of transparent and colored W(x)Si(y)O(z) thin films by magnetron sputtering (MS) from a single cathode. The films were characterized by a large set of techniques including X-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectrometry (RBS), Fourier transform infrared (FT-IR), and Raman spectroscopies. Their optical properties were determined by the analysis of the transmission and reflection spectra. It was found that both the relative amount of tungsten in the W-Si MS target and the ratio O(2)/Ar in the plasma gas were critical parameters to control the blue coloration of the films. The long-term stability of the color, attributed to the formation of a high concentration of W(5+) and W(4+) species, has been related with the formation of W-O-Si bond linkages in an amorphous network. At normal geometry (i.e., substrate surface parallel to the target) the films were rather compact, whereas they were very porous and had less tungsten content when deposited in a glancing angle configuration. In this case, they presented outstanding electrochromic properties characterized by a fast response, a high coloration, a complete reversibility after more than one thousand cycles and a relatively very low refractive index in the bleached state. PMID:22208156

  7. Quantitative electrochemical and electrochromic behavior of terthiophene and carbazole containing conjugated polymer network film precursors: EC-QCM and EC-SPR.

    PubMed

    Taranekar, Prasad; Fulghum, Timothy; Baba, Akira; Patton, Derek; Advincula, Rigoberto

    2007-01-16

    A comparative analysis of the copolymerization behavior between an electro-active terthiophene and a carbazole moiety of a conjugated polymer precursor was investigated using electrochemical and hyphenated electrochemical methods. Five different precursor polymers were first synthesized and characterized using NMR, IR, and GPC. The polymers include homopolymers of individual electro-active groups (P3T, P-CBZ) and different compositions of 25, 50, and 75% (P3TC-25, P3TC50, and P3TC-75) with respect to the two electro-active groups. Since the oxidation potentials of terthiophene and carbazole lie very close to each other, highly cross-linked copolymer films of varying extent were produced depending on the composition. The copolymerization extent was found to be dependent primarily on the amount of the terthiophene, which in this case provided for a more efficient carbazole polymerization and copolymerization than with just carbazole alone (homopolymer). The extent of copolymerization, electrochromic properties, and viscoelastic changes was quantitatively investigated using a number of hyphenated electrochemistry techniques: spectro-electrochemistry, electrochemical quartz crystal microbalance studies (EC-QCM), and electrochemical surface plasmon resonance spectroscopy (EC-SPR). Each technique revealed a unique aspect of the electrocopolymerization behavior that was used to define structure-property relationships and the deposition/copolymerization mechanism.

  8. Characterization of dynamic thermal control schemes and heat transfer pathways for incorporating variable emissivity electrochromic materials into a space suit heat rejection system

    NASA Astrophysics Data System (ADS)

    Massina, Christopher James

    The feasibility of conducting long duration human spaceflight missions is largely dependent on the provision of consumables such as oxygen, water, and food. In addition to meeting crew metabolic needs, water sublimation has long served as the primary heat rejection mechanism in space suits during extravehicular activity (EVA). During a single eight hour EVA, approximately 3.6 kg (8 lbm) of water is lost from the current suit. Reducing the amount of expended water during EVA is a long standing goal of space suit life support systems designers; but to date, no alternate thermal control mechanism has demonstrated the ability to completely eliminate the loss. One proposed concept is to convert the majority of a space suit's surface area into a radiator such that the local environment can be used as a radiative thermal sink for rejecting heat without mass loss. Due to natural variations in both internal (metabolic) loads and external (environmental) sink temperatures, radiative transport must be actively modulated in order to maintain an acceptable thermal balance. Here, variable emissivity electrochromic devices are examined as the primary mechanism for enabling variable heat rejection. This dissertation focuses on theoretical and empirical evaluations performed to determine the feasibility of using a full suit, variable emissivity radiator architecture for space suit thermal control. Operational envelopes are described that show where a given environment and/or metabolic load combination may or may not be supported by the evaluated thermal architecture. Key integration considerations and guidelines include determining allowable thermal environments, defining skin-to-radiator heat transfer properties, and evaluating required electrochromic performance properties. Analysis also considered the impacts of dynamic environmental changes and the architecture's extensibility to EVA on the Martian surface. At the conclusion of this work, the full suit, variable emissivity

  9. Sputter deposition of MgxAlyOz thin films in a dual-magnetron device: a multi-species Monte Carlo model

    NASA Astrophysics Data System (ADS)

    Yusupov, M.; Saraiva, M.; Depla, D.; Bogaerts, A.

    2012-07-01

    A multi-species Monte Carlo (MC) model, combined with an analytical surface model, has been developed in order to investigate the general plasma processes occurring during the sputter deposition of complex oxide films in a dual-magnetron sputter deposition system. The important plasma species, such as electrons, Ar+ ions, fast Ar atoms and sputtered metal atoms (i.e. Mg and Al atoms) are described with the so-called multi-species MC model, whereas the deposition of MgxAlyOz films is treated by an analytical surface model. Target-substrate distances for both magnetrons in the dual-magnetron setup are varied for the purpose of growing stoichiometric complex oxide thin films. The metal atoms are sputtered from pure metallic targets, whereas the oxygen flux is only directed toward the substrate and is high enough to obtain fully oxidized thin films but low enough to avoid target poisoning. The calculations correspond to typical experimental conditions applied to grow these complex oxide films. In this paper, some calculation results are shown, such as the densities of various plasma species, their fluxes toward the targets and substrate, the deposition rates, as well as the film stoichiometry. Moreover, some results of the combined model are compared with experimental observations. Note that this is the first complete model, which can be applied for large and complicated magnetron reactor geometries, such as dual-magnetron configurations. With this model, we are able to describe all important plasma species as well as the deposition process. It can also be used to predict film stoichiometries of complex oxide films on the substrate.

  10. Transcatheter closure of atrial septal defect and patent foramen ovale in adult patients using the Amplatzer occlusion device: no evidence for thrombus deposition with antiplatelet agents.

    PubMed

    Brandt, Roland R; Neumann, Thomas; Neuzner, Jörg; Rau, Matthias; Faude, Ingrid; Hamm, Christian W

    2002-10-01

    Transcatheter closure of atrial septal defect (ASD) and patent foramen ovale (PFO) using the Amplatzer septal occluder (AGA Medical, Minneapolis, Minn) is an alternative to surgical closure. There are only limited data on the thrombogenic potential of the device. Thirty-seven patients (14 men, 23 women) underwent device closure of their ASD (n = 21) or PFO (n = 16) at a mean age of 47 +/- 14 years (range, 18-72). The device was successfully deployed in all patients. Thirty-three of 37 patients received antiplatelet therapy with clopidogrel bisulfate and aspirin for a total of 6 months. Four patients in atrial fibrillation were also anticoagulated (international normalized ratio 2.0 to 3.0). No thrombus was detected in any patient on either side of the device by transthoracic and transesophageal echocardiography and there were no cases of symptomatic thromboembolism. Right-to-left interatrial shunting was diagnosed by contrast transesophageal echocardiography with the Valsalva's maneuver. At 1-month follow-up, minimal right-to-left shunting was detected in 6 patients (2 PFO, 4 ASD). Two patients (PFO) had minimal shunting at 1 month but not at 6 months. In 3 patients (ASD), inducible right-to-left shunting persisted at 6 months. In conclusion, our results obtained from a modest number of patients indicate that antiplatelet therapy is safe and effective in preventing thrombus formation on the septal occluder surface. PMID:12373252

  11. Synthesis of 2-(selenophen-2-yl)pyrroles and their electropolymerization to electrochromic nanofilms.

    PubMed

    Trofimov, Boris A; Schmidt, Elena Yu; Mikhaleva, Albina I; Pozo-Gonzalo, Cristina; Pomposo, Jose A; Salsamendi, Maitane; Protzuk, Nadezhda I; Zorina, Nadezhda V; Afonin, Andrey V; Vashchenko, Alexander V; Levanova, Ekaterina P; Levkovskaya, Galina G

    2009-06-22

    Bridging pyrrole and selenophene chemistries: Molecular assemblies have been developed that allow scrutiny of the electronic communication between pyrrole and selenophene nuclei. Divergent syntheses of 2-(selenophen-2-yl)pyrroles and their N-vinyl derivatives from available 2-acylselenophenes and acetylenes in a one-pot procedure have been devised (see scheme), which provide access to these exotic heterocyclic ensembles.The divergent syntheses of 2-(selenophen-2-yl)pyrroles and their N-vinyl derivatives from available 2-acylselenophenes and acetylenes in a one-pot procedure make these exotic heterocyclic ensembles accessible. Now we face a potentially vast area for exploration with a great diversity of far-reaching consequences including conducting electrochromic polymers with repeating of pyrrole and selenophene units (emerging rivalry for polypyrroles and polyselenophenes), the synthesis of functionalized pyrrole-selenophene assembles for advanced materials, biochemistry and medicine, exciting models for theory of polymer conductivity.

  12. Multicolor and fast electrochromic P(DTB-EDOT)/ZnO nanocomposite film.

    PubMed

    Mi, Ouyang; Lv, Xiaojing; Hu, Bin; Wang, Genghao; Zhang, Cheng

    2013-02-01

    In this work, uniform and controllable size of ZnO nanoparticles were fabricated via solution-phase approach, and the copolymer based on the monomers of 1,4-di(thiophen-3-yl)benzene (DTB) and 3,4-ethylenedioxythiophene (EDOT) was successfully synthesized with electrochemical polymerization. A new P(DTB-EDOT)/ZnO nanocomposite film was obtained via situ preparation. Cyclic voltammogram and spectroelectrochemical characterization showed that the composite film had a stable and well-defined reversible redox process as well as electrochromic behavior. Besides, the composite film exhibited fast switching time (1 s at 746 nm), significant optical contrast and a variety of colors (red, ochre, green and blue) under different potentials. PMID:23646634

  13. Design goals and challenges for a photovoltaic-powered electrochromic window covering

    SciTech Connect

    Benson, D K; Branz, H M

    1994-12-01

    An estimated 1.0%-1.5% of the total cooling energy need in U.S. buildings, and 10%-30% of the peak electric utility power demand, is caused by unwanted solar heat-gain through windows. A large fraction of the approximately two billion square meters of building windows in the United States could benefit from the use of some solar gain control strategy. If a cost-effective, retrofit, electrochromic (EC) window covering were available, this energy savings potential could be realized in a relatively short time. A {open_quotes}glue on{close_quotes}, retrofit EC window treatment, similar to conventional static solar-gain control .films, could accelerate the application of this new technology in buildings. However, the costs of electrical wiring for each retrofitted window could dominate the economics of the retrofit decision and slow market acceptance of EC-windows. By incorporating a photovoltaic (PV) power source into the EC window retrofit, this wiring cost could be reduced or eliminated, and the installation of the EC window treatment could be greatly simplified. In this paper, we suggest the use of an integrated, photovoltaic-powered electrochromic (PV-EC) window treatment that can be applied to an existing window in much the same way that conventional, static, solar-gain control films are now applied. This concept is the subject of a new three-year research and development (R&D) project at our laboratory. We present our design concepts and rationale and identify some of the technical challenges involved.

  14. Construction of a 3D porous network of copper film via a template-free deposition method with superior mechanical and electrical properties for micro-energy devices

    NASA Astrophysics Data System (ADS)

    Peng, Yuncheng; Wang, Yao; Deng, Yuan

    2016-08-01

    With the ever increasing level of performance of energy conversion micro-devices, such as thin-film solar cells and thermoelectric micro-generators or coolers, their reliability and stability still remain a challenge. The high electrical and mechanical stability of an electrode is two of the critical factors that affect the long-term life of devices. Here we show that these factors can be achieved by constructing a 3D porous network of nanostructures in copper film using facile magnetron sputtering technology without any templates. The constructed 3D porous network of nanostructures in Cu film provides not only the advantages of light weight, prominently high conductivity, and large elastic deformation, but also the ability to absorb stress, preventing crack propagation, which is crucial for electrodes to maintain stable electrical and mechanical properties under working conditions. The nanopores inside the 3D network are capable of unrestrained deformation under applied stress resulting in strong elastic recovery. This work puts forward a feasible solution for manufacturing electrodes with excellent electrical and mechanical properties for micro-energy devices.

  15. Electrochemical co-deposition of conductive polymer-silica hybrid thin films.

    PubMed

    Raveh, Moran; Liu, Liang; Mandler, Daniel

    2013-07-14

    Conductive polymers, such as polypyrrole (ppy), have been the subject of numerous studies due to their promising applications in organic solar cells, flexible electronics, electrochromic devices, super capacitors, etc. Yet, their application is still limited as a result of poor processability. Silica has been reported to improve the mechanical strength and adhesion of conductive polymer films. In this work, we propose a controllable electrochemical approach for preparing ppy-silica hybrid thin films from a solution containing both pyrrole and silane monomers. It is known that pyrrole can be electropolymerised using anodic potentials, while silica can be electrodeposited under cathodic potentials. Thus, we studied the formation of ppy-silica hybrid thin films on a stainless steel surface by applying alternating potentials, i.e. cathodic followed by anodic pulses (denoted C + A) or anodic followed by cathodic pulses (denoted A + C). We show that by controlling the deposition potential and time for the cathodic and anodic pulses, the film thickness and composition can be manipulated well as analysed using profilometry and EDX. The element depth profile of the films was characterized using secondary ion mass spectroscopy (SIMS). In essence, for the C + A process, pyrrole diffuses through the cathodically electrodeposited wet silica gel layer and undergoes anodic polymerisation on the substrate, while for the A + C process, silane can be electrodeposited both on top of the anodically electrodeposited conductive ppy films as well as on the stainless steel through the pinholes in the ppy film. This offers a simple approach for tuning the structure of conductive polymer-sol-gel composite films.

  16. Aluminum doped nickel oxide thin film with improved electrochromic performance from layered double hydroxides precursor in situ pyrolytic route

    NASA Astrophysics Data System (ADS)

    Shi, Jingjing; Lai, Lincong; Zhang, Ping; Li, Hailong; Qin, Yumei; Gao, Yuanchunxue; Luo, Lei; Lu, Jun

    2016-09-01

    Electrochromic materials with unique performance arouse great interest on account of potential application values in smart window, low-power display, automobile anti-glare rearview mirror, and e-papers. In this paper, high-performing Al-doped NiO porous electrochromic film grown on ITO substrate has been prepared via a layered double hydroxides(LDHs) precursor in situ pyrolytic route. The Al3+ ions distributed homogenously within the NiO matrix can significantly influence the crystallinity of Ni-Al LDH and NiO:Al3+ films. The electrochromic performance of the films were evaluated by means of UV-vis absorption spectroscopy, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry(CA) measurements. In addition, the ratio of Ni3+/Ni2+ also varies with Al content which can lead to different electrochemical performances. Among the as-prepared films, NiO film prepared from Ni-Al (19:1) LDH show the best electrochromic performance with a high transparency of 96%, large optical modulation range (58.4%), fast switching speed (bleaching/coloration times are 1.8/4.2 s, respectively) and excellent durability (30% decrease after 2000 cycles). The improved performance was owed to the synergy of large NiO film specific surface area and porous morphology, as well as Al doping stifled the formation of Ni3+ making bleached state more pure. This LDHs precursor pyrolytic method is simple, low-cost and environmental benign and is feasible for the preparation of NiO:Al and other Al-doped oxide thin film.

  17. Bio-inspired materials for electrochemical devices

    NASA Astrophysics Data System (ADS)

    Pawlicka, A.; Firmino, A.; Sentanin, F.; Sabadini, R. C.; Jimenez, D. E. Q.; Jayme, C. C.; Mindroiu, M.; Zgarian, R. G.; Tihan, G. T.; Rau, I.; Silva, M. M.; Nogueira, A. F.; Kanicki, J.; Kajzar, F.

    2015-10-01

    Natural macromolecules are very promising row materials to be used in modern technology including security and defense. They are abundant in nature, easy to extract and possess biocompatibility and biodegradability properties. These materials can be modified throughout chemical or physical processes, and can be doped with lithium and rare earth salts, ionic liquids, organic and inorganic acids. In this communication samples of DNA and modified DNA were doped with Prussian Blue (PB), poly(ethylene dioxythiophene) (PEDOT), europium and erbium triflate and organic dyes such as Nile Blue (NB), Disperse Red 1 (DR1) and Disperse Orange 3 (DO3). The colored or colorless membranes were characterized by electrochemical and spectroscopic measurements, and they were applied in electrochromic devices (ECDs) and dye sensitized solar cells (DSSC). ECDs change the color under applied potential, so they can modulate the intensity of transmitted light of 15 to 35%. As the electrochromic materials, WO3 or Prussian blue (PB), are usually blue colored, the color change is from transparent to blue. DNA, and the complexes: DNA-CTMA, DNA-DODA and DNAPEDOT: PSS were also investigated as either hole carrier material (HTM) or polymer electrolyte in dye-sensitized solar cells (DSSC). The DNA-based samples as HTM in small DSSCs revealed a solar energy conversion efficiency of 0.56%. Polymer electrolytes of DNA-CTMA and DNA-DODA, both with 10 wt% of LiI/I2, applied in small DSSC, exhibited the efficiencies of 0.18 and 0.66%, respectively. The obtained results show that natural macromolecules-based membranes are not only environmentally friendly but are also promising materials to be investigated for several electrochemical devices. However, to obtain better performances more research is still needed.

  18. Optical, structural and electrochromic behavior studies on nanocomposite thin film of aniline, o-toluidine and WO3

    NASA Astrophysics Data System (ADS)

    Najafi-Ashtiani, Hamed; Bahari, Ali

    2016-08-01

    In the field of materials for electrochromic (EC) applications much attention was paid to the derivatives of aniline. We report on the optical, structural and electrochromic properties of electrochromic thin film based on composite of WO3 nanoparticles and copolymer of aniline and o-toluidine prepared by electrochemical polymerization method on fluorine doped tin oxide (FTO) coated glass. The thin film was studied by X-ray diffraction (XRD) and Fourier transforms infrared (FTIR) spectroscopy. The morphology of prepared thin film was characterized by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and the thermal gravimetric analysis (TGA) as well. The optical spectra of nanocomposite thin film were characterized in the 200-900 nm wavelength range and EC properties of nanocomposite thin film were studied by cyclic voltammetry (CV). The calculation of optical band gaps of thin film exhibited that the thin film has directly allowed transition with the values of 2.63 eV on first region and 3.80 eV on second region. Dispersion parameters were calculated based on the single oscillator model. Finally, important parameters such as dispersion energy, oscillator energy and lattice dielectric constant were determined and compared with the data from other researchers. The nonlinear optical properties such as nonlinear optical susceptibility, nonlinear absorption coefficient and nonlinear refractive index were extracted. The obtained results of nanocomposite thin film can be useful for the optoelectronic applications.

  19. Flexible electrochromics: magnetron sputtered tungsten oxide (WO3-x) thin films on Lexan (optically transparent polycarbonate) substrates

    NASA Astrophysics Data System (ADS)

    Uday Kumar, K.; Murali, Dhanya S.; Subrahmanyam, A.

    2015-06-01

    Tungsten oxide (WO3-x) based electrochromics on flexible substrates is a topic of recent interest. The present communication reports the electrochromic properties of WO3-x thin films grown on lexan, an optically transparent polycarbonate thermoplastic substrate. The WO3-x films are prepared at room temperature (300 K) by the reactive DC magnetron sputtering technique. The physical properties of metal oxide thin films are known to be controlled by the oxygen stoichiometry of the film. In the present work, the WO3-x thin films are prepared by varying the oxygen flow rates. All the WO3-x thin films are amorphous in nature. The electrochromic performance of the WO3-x thin films is evaluated by cyclic voltammetry measurements on tin doped indium oxide (ITO) coated lexan and glass substrates. The optical band gap of WO3-x thin films grown on lexan substrates (at any given oxygen flow rate) is significantly higher than those grown on glass substrates. The coloration efficiency of WO3-x thin films (at an oxygen flow rate of 10 sccm) on lexan substrates is: 143.9 cm2 C-1 which is higher compared to that grown on glass: 90.4 cm2 C-1.

  20. Electrochromic Radiator Coupon Level Testing and Full Scale Thermal Math Modeling for Use on Altair Lunar Lander

    NASA Technical Reports Server (NTRS)

    Bannon, Erika T.; Bower, Chad E.; Sheth, Rubik; Stephan, Ryan

    2010-01-01

    In order to control system and component temperatures, many spacecraft thermal control systems use a radiator coupled with a pumped fluid loop to reject waste heat from the vehicle. Since heat loads and radiation environments can vary considerably according to mission phase, the thermal control system must be able to vary the heat rejection. The ability to "turn down" the heat rejected from the thermal control system is critically important when designing the system. Electrochromic technology as a radiator coating is being investigated to vary the amount of heat rejected by a radiator. Coupon level tests were performed to test the feasibility of this technology. Furthermore, thermal math models were developed to better understand the turndown ratios required by full scale radiator architectures to handle the various operation scenarios encountered during a mission profile for the Altair Lunar Lander. This paper summarizes results from coupon level tests as well as the thermal math models developed to investigate how electrochromics can be used to increase turn down ratios for a radiator. Data from the various design concepts of radiators and their architectures are outlined. Recommendations are made on which electrochromic radiator concept should be carried further for future thermal vacuum testing.

  1. Electrochromic Radiator Coupon Level Testing and Full Scale Thermal Math Modeling for Use on Altair Lunar Lander

    NASA Technical Reports Server (NTRS)

    Sheth, Rubik; Bannon, Erika; Bower, Chad

    2009-01-01

    In order to control system and component temperatures, many spacecraft thermal control systems use a radiator coupled with a pumped fluid loop to reject waste heat from the vehicle. Since heat loads and radiation environments can vary considerably according to mission phase, the thermal control system must be able to vary the heat rejection. The ability to "turn down" the heat rejected from the thermal control system is critically important when designing the system.. Electrochromic technology as a radiator coating is being investigated to vary the amount of heat being rejected by a radiator. Coupon level tests were performed to test the feasibility of the technology. Furthermore, thermal math models were developed to better understand the turndown ratios required by full scale radiator architectures to handle the various operation scenarios during a mission profile for Altair Lunar Lander. This paper summarizes results from coupon level tests as well as thermal math models developed to investigate how electrochromics can be used to provide the largest turn down ratio for a radiator. Data from the various design concepts of radiators and their architectures are outlined. Recommendations are made on which electrochromic radiator concept should be carried further for future thermal vacuum testing.

  2. Solution deposition assembly

    SciTech Connect

    Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

    2014-01-21

    Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

  3. Structure, stability and electrochromic properties of polyaniline film covalently bonded to indium tin oxide substrate

    NASA Astrophysics Data System (ADS)

    Zhang, Wenzhi; Ju, Wenxing; Wu, Xinming; Wang, Yan; Wang, Qiguan; Zhou, Hongwei; Wang, Sumin; Hu, Chenglong

    2016-03-01

    Indium tin oxide (ITO) substrate was modified with 4-aminobenzylphosphonic acid (ABPA), and then the polyaniline (PANI) film covalently bonded to ITO substrate was prepared by the chemical oxidation polymerization. X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared (ATR-IR) spectroscopy, and atomic force microscopy (AFM) measurements demonstrated that chemical binding was formed between PANI and ABPA-modified ITO surface, and the maximum thickness of PANI layer is about 30 nm. The adhesive strength of PANI film on ITO substrate was tested by sonication. It was found that the film formed on the modified ITO exhibited a much better stability than that on bare one. Cyclic voltammetry (CV) and UV-vis spectroscopy measurements indicated that the oxidative potentials of PANI film on ABPA-modified ITO substrate were decreased and the film exhibited high electrochemical activities. Moreover, the optical contrast increased from 0.58 for PANI film (without ultrasound) to 1.06 for PANI film (after ultrasound for 60 min), which had an over 83% enhancement. The coloration time was 20.8 s, while the bleaching time was 19.5 s. The increase of electrochromic switching time was due to the lower ion diffusion coefficient of the large cation of (C4H9)4N+ under the positive and negative potentials as comparison with the small Li+ ion.

  4. Composite WO3/TiO2 nanostructures for high electrochromic activity

    DOE PAGESBeta

    Reyes-Gil, Karla R.; Stephens, Zachary D.; Stavila, Vitalie; Robinson, David B.

    2015-01-06

    A composite material consisting of TiO2 nanotubes (NT) with WO3 electrodeposited on its surface has been fabricated, detached from its Ti substrate, and attached to a fluorine-doped tin oxide (FTO) film on glass for application to electrochromic (EC) reactions. Several adhesion layers were tested, finding that a paste of TiO2 made from commercially available TiO2 nanoparticles creates an interface for the TiO2 NT film to attach to the FTO glass, which is conductive and does not cause solution-phase ions in an electrolyte to bind irreversibly with the material. The effect of NT length and WO3 concentration on the EC performancemore » were studied. As a result, the composite WO3/TiO2 nanostructures showed higher ion storage capacity, better stability, enhanced EC contrast, and longer memory time compared with the pure WO3 and TiO2 materials« less

  5. Composite WO3/TiO2 nanostructures for high electrochromic activity.

    SciTech Connect

    Reyes, Karla Rosa; Stephens, Zachary Dan.; Robinson, David B.

    2013-05-01

    A composite material consisting of TiO2 nanotubes (NTs) with WO3 electrodeposited homogeneously on its surface has been fabricated, detached from its substrate, and attached to a fluorine-doped tin oxide film on glass for application to electrochromic (EC) reactions. A paste of TiO2 made from commercially available TiO2 nanoparticles creates an interface for the TiO2 NT film to attach to the FTO glass, which is conductive and does not cause solution-phase ions in an electrolyte to bind irreversibly with the material. The effect of NT length on the current density and the EC contrast of the material were studied. The EC redox reaction seen in this material is diffusion- limited, having relatively fast reaction rates at the electrode surface. The composite WO3/TiO2 nanostructures showed higher ion storage capacity, better stability, enhanced EC contrast and longer memory time compared with the pure WO3 and TiO2.

  6. Monitored Energy Performance of Electrochromic Windows Controlledfor Daylight and Visual Comfort

    SciTech Connect

    Lee, Eleanor S.; DiBartolomeo, Dennis L.; Klems, Joseph; Yazdanian, Mehry; Selkowitz, Stephen E.

    2005-09-23

    A 20-month field study was conducted to measure the energy performance of south-facing large-area tungsten-oxide absorptive electrochromic (EC) windows with a broad switching range in a private office setting. The EC windows were controlled by a variety of means to bring in daylight while minimizing window glare. For some cases, a Venetian blind was coupled with the EC window to block direct sun. Some tests also involved dividing the EC window wall into zones where the upper EC zone was controlled to admit daylight while the lower zone was controlled to prevent glare yet permit view. If visual comfort requirements are addressed by EC control and Venetian blinds, a 2-zone EC window configuration provided average daily lighting energy savings of 10 {+-} 15% compared to the reference case with fully lowered Venetian blinds. Cooling load reductions were 0 {+-} 3%. If the reference case assumes no daylighting controls, lighting energy savings would be 44 {+-} 11%. Peak demand reductions due to window cooling load, given a critical demand-response mode, were 19-26% maximum on clear sunny days. Peak demand reductions in lighting energy use were 0% or 72-100% compared to a reference case with and without daylighting controls, respectively. Lighting energy use was found to be very sensitive to how glare and sun is controlled. Additional research should be conducted to fine-tune EC control for visual comfort based on solar conditions so as to increase lighting energy savings.

  7. Electrooptical devices

    NASA Astrophysics Data System (ADS)

    Hurwitz, C. E.

    1980-03-01

    This report covers work carried out with support of the Department of the Air Force during the period 1 October 1979 through 31 March 1980. A part of this support was provided by the Rome Air Development Center. CW operation at temperatures up to 55 C has been achieved for GaInAsP/InP double-heterostructure (DH) lasers emitting at 1.5 micrometers, which were grown without a GaInAsP buffer layer. These devices are of interest for use as sources in fiber-optics communications systems, since the lowest transmission loss reported for fused-silica optical fibers occurs at 1.55 micrometers. Surface passivation techniques developed for InP and GaInAsP avalanche photodiodes have resulted in reductions of dark current as large as four orders of magnitude, to values as low as .0000016 A/sq cm at 0.9 V(b) where V(b) is the breakdown voltage. Devices consisting entirely of InP have been passivated with plasma-deposited Si3N4, and those with a GaInAsP layer but with the p-n junction in InP have been passivated with polyimide. Neither of these techniques successfully reduces dark currents in devices with the p-n junction in the GaInAsP, but a film of photoresist sprayed with SF6 as the propellant has given excellent results. The electrical characteristics in InP ion implanted with Sn, Ge, Si, and C have been investigated. All of these column IV elements yielded n-type conductivity and Sn, Ge, and Si showed high electrical activation; however, implanted C was found to have a net electrical activation of only about 5 percent.

  8. Time-resolved electrochromism associated with the formation of quinone anions in the rhodobacter sphaeroides R26 reaction center

    SciTech Connect

    Tiede, D.M.; Vazquez, J.; Cordova, J.; Marone, P.A.

    1996-08-20

    The bacterial photosynthetic reaction center contains bacteriochlorophyll (Bchl) and bacteriochlorophyll (Bchl) and bacteriopheophytin (Bph) cofactors that provide natural probes of electrostatic fields within this protein. We have examined the electrochromic responses of these cofactors, resolved during the lifetimes of the quinone anion states, P{sup +}Q{sub A}{sup -Q}{sub B} and P{sup +}Q{sub A}Q{sub B}{sup -}, and measured as a function of temperature. These measurements provide information on the time-dependent variation in electrostatic field strength on the Bchl and Bph cofactors. Measurements in the near-infrared absorbance bands are described. 60 refs., 11 figs., 1 tab.

  9. Magnetron sputter-deposited multilayer (Ba{sub x}Sr{sub 1x})Ti{sub 1+y}O{sub 3+z} thin films for passive and active devices.

    SciTech Connect

    Im, J.; Auciello, O.; Baumann, P. K.; Streiffer, S. K.; Kaufman, D. Y.; Krauss, A. R.

    2001-01-01

    High permittivity (Ba{sub x}Sr{sub 1-x})Ti{sub 1+y}O{sub 3+z}(BST) thin films are being investigated for integration into charge storage dielectrics and electric-field tunable elements for high frequency devices. For the latter application, it is desirable to have BST capacitors with high tunability and low losses. Therefore, we investigated the use of multilayer BST thin films consisting of very low dielectric loss BST/electrode interfacial layers ((Ba+Sr)/Ti = 0.73) sandwiching a high tunability, high permittivity primary BST layer ((Ba+Sr)/Ti = 0.9). BST capacitors with multiple layers of controlled composition can be effectively produced insitu by magnetron sputter deposition, using a single stoichiometric target and controlling the layer composition by changing the total process gas (Ar+O<{sub 2}) pressure. The layered BST film capacitors exhibit simultaneous low loss (tan {Delta} = 0.005), high tunability (76%), high charge storage energy density (34 J/cm{sup 3}), low leakage, and high dielectric breakdown (>2.8 MV/cm).

  10. Catalyst patterning for nanowire devices

    NASA Technical Reports Server (NTRS)

    Li, Jun (Inventor); Cassell, Alan M. (Inventor); Han, Jie (Inventor)

    2004-01-01

    Nanowire devices may be provided that are based on carbon nanotubes or single-crystal semiconductor nanowires. The nanowire devices may be formed on a substrate. Catalyst sites may be formed on the substrate. The catalyst sites may be formed using lithography, thin metal layers that form individual catalyst sites when heated, collapsible porous catalyst-filled microscopic spheres, microscopic spheres that serve as masks for catalyst deposition, electrochemical deposition techniques, and catalyst inks. Nanowires may be grown from the catalyst sites.

  11. Bis(tetrabenzotriazaporphyrinato) and (tetrabenzotriazaporphyrinato)(phthalocyaninato) lutetium(III) complexes--novel sandwich-type tetrapyrrolic ligand based NIR absorbing electrochromes.

    PubMed

    Pushkarev, Victor E; Kalashnikov, Valery V; Trashin, Stanislav A; Borisova, Nataliya E; Tomilova, Larisa G; Zefirov, Nikolay S

    2013-09-14

    The first sandwich-type complexes have been prepared for tetrabenzotriazaporphyrin ligands. The compounds reveal intrinsic UV-Vis/NIR absorption as well as peculiar electrochromic behavior. The heteroleptic (tetrabenzotriazaporphyrinato)(phthalocyaninato) lutetium derivative shows intermediate spectral and electrochemical properties with respect to homoleptic relatives.

  12. Optical and electrochemical properties of Cu-doped NiO films prepared by electrochemical deposition

    NASA Astrophysics Data System (ADS)

    Zhao, Lili; Su, Ge; Liu, Wei; Cao, Lixin; Wang, Jing; Dong, Zheng; Song, Meiqin

    2011-02-01

    Cu-doped nickel oxide (NiO) thin films were prepared by electrochemial deposition (cathodic deposition) technique onto the fluorine doped tin oxide (F: SnO2; FTO) coated glass substrates from organic solutions. Effects of Cu content on the morphology, structure, optical and electrochromic properties of NiO films were investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet-visible spectrophotometer (UV-vis) and cyclic voltammetry (CV), respectively. SEM images indicated the formation of nanorods after Cu was added. The films were formed with amorphous or short-range ordered NiO grains and a trace of face-centered cubic NixCu1-xO confirmed by XRD. The transmittances of both bleached state and colored state were significantly lowered when Cu was added. The NiO films doped with Cu (the molar ratio was 1/8) exhibited the optimum electrochromic behavior with a variation of transmittance (ΔT) up to ∼80% at the wavelength range of 350-600 nm. Cu doping reduces the response time for both the coloring and bleaching states, and the reversibility of the redox reaction was increased as well.

  13. Virus-templated iridium oxide-gold hybrid nanowires for electrochromic application

    NASA Astrophysics Data System (ADS)

    Nam, Yoon Sung; Park, Heechul; Magyar, Andrew P.; Yun, Dong Soo; Pollom, Thomas S.; Belcher, Angela M.

    2012-05-01

    A highly porous electrode comprised of biologically templated iridium oxide-gold (IrO2-Au) hybrid nanowires is introduced for electrochromic applications. A filamentous M13 virus is genetically engineered to display IrO2-binding peptides on the viral surface and used as a template for the self-assembly of IrO2 nanoclusters into a nanowire. The open porous morphology of the prepared nanowire film facilitates ion transport. Subsequently, the redox kinetics of the IrO2 nanowires seems to be limited by the electric resistance of the nanowire film. To increase the electron mobility in the nanowires, gold nanoparticles are chemically linked to the virus prior to the IrO2 mineralization, forming a gold nanostring structure along the long axis of the virus. The resulting IrO2-Au hybrid nanowires exhibit a switching time of 35 ms for coloration and 25 ms for bleaching with a transmission change of about 30.5% at 425 nm. These values represent almost an order of magnitude faster switching responses than those of an IrO2 nanowire film having the similar optical contrast. This work shows that genetically engineered viruses can serve as versatile templates to co-assemble multiple functional molecules, enabling control of the electrochemical properties of nanomaterials.A highly porous electrode comprised of biologically templated iridium oxide-gold (IrO2-Au) hybrid nanowires is introduced for electrochromic applications. A filamentous M13 virus is genetically engineered to display IrO2-binding peptides on the viral surface and used as a template for the self-assembly of IrO2 nanoclusters into a nanowire. The open porous morphology of the prepared nanowire film facilitates ion transport. Subsequently, the redox kinetics of the IrO2 nanowires seems to be limited by the electric resistance of the nanowire film. To increase the electron mobility in the nanowires, gold nanoparticles are chemically linked to the virus prior to the IrO2 mineralization, forming a gold nanostring

  14. Daylighting control performance of a thin-film ceramic electrochromic window: Field study results

    SciTech Connect

    Lee, E.S.; DiBartolomeo, D.L.; Selkowitz, S.E.

    2005-01-26

    Control system development and lighting energy monitoring of ceramic thin-film electrochromic (EC) windows were initiated at the new full-scale window systems test-bed facility at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA. The new facility consists of three identically configured side-by-side private offices with large-area windows that face due south. In one room, an array of EC windows with a center-of-glass visible transmittance T_v range of 0.05-0.60 was installed. In the two other rooms, unshaded windows with a T_v = 0.50 or 0.15 were used as reference. The same dimmable fluorescent lighting system was used in all three rooms. This study explains the design and commissioning of an integrated EC window-lighting control system, and then illustrates its performance in the test-bed under clear, partly cloudy, and overcast sky conditions during the equinox period. The performance of an early prototype EC window controller is also analyzed. Lighting energy savings data are presented. Daily lighting energy savings were 44-59% compared to the reference window of T_v = 0.15 and 8-23% compared to the reference window of T_v = 0.50. The integrated window-lighting control system maintained interior illuminance levels to within +/- 10% of the setpoint range of 510-700 lx for 89-99% of the day. Further work is planned to refine the control algorithms and monitor cooling load, visual comfort, and human factor impacts of this emerging technology. (author)

  15. Revealing the Functional States in the Active Site of BLUF Photoreceptors from Electrochromic Shift Calculations

    PubMed Central

    2014-01-01

    Photoexcitation with blue light of the flavin chromophore in BLUF photoreceptors induces a switch into a metastable signaling state that is characterized by a red-shifted absorption maximum. The red shift is due to a rearrangement in the hydrogen bond pattern around Gln63 located in the immediate proximity of the isoalloxazine ring system of the chromophore. There is a long-lasting controversy between two structural models, named Q63A and Q63J in the literature, on the local conformation of the residues Gln63 and Tyr21 in the dark state of the photoreceptor. As regards the mechanistic details of the light-activation mechanism, rotation of Gln63 is opposed by tautomerism in the Q63A and Q63J models, respectively. We provide a structure-based simulation of electrochromic shifts of the flavin chromophore in the wild type and in various site-directed mutants. The excellent overall agreement between experimental and computed data allows us to evaluate the two structural models. Compelling evidence is obtained that the Q63A model is incorrect, whereas the Q63J is fully consistent with the present computations. Finally, we confirm independently that a keto–enol tautomerization of the glutamine at position 63, which was proposed as molecular mechanism for the transition between the dark and the light-adapted state, explains the measured 10 to 15 nm red shift in flavin absorption between these two states of the protein. We believe that the accurateness of our results provides evidence that the BLUF photoreceptors absorption is fine-tuned through electrostatic interactions between the chromophore and the protein matrix, and finally that the simplicity of our theoretical model is advantageous as regards easy reproducibility and further extensions. PMID:25153778

  16. Planar electrochemical device assembly

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2007-06-19

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  17. Planar electrochemical device assembly

    DOEpatents

    Jacobson; Craig P. , Visco; Steven J. , De Jonghe; Lutgard C.

    2010-11-09

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  18. The electrochemistry of transparent quantum size rutile nanowire thin films prepared by one-step low temperature chemical bath deposition

    NASA Astrophysics Data System (ADS)

    Berger, Thomas; Lana-Villarreal, Teresa; Monllor-Satoca, Damián; Gómez, Roberto

    2007-10-01

    We performed a spectro- and photoelectrochemical study of electrodes consisting of oriented rutile TiO 2 nanowires with a diameter of ˜2 nm prepared directly by chemical bath deposition on conducting glass. A significant increase (around 0.25 eV with respect to bulk rutile) of the band gap energy for the nanowire film is observed and attributed to quantum size effects, pointing to the presence of individual monocrystalline nanowires with no significant electronic communication among them. This allows for the investigation of morphologically well defined electrodes in the two dimensional quantum confinement regime, which are characterized by particularly good photoelectrocatalytic and electrochromic properties.

  19. A Pilot Demonstration of Electrochromic and Thermochromic Windows in the Denver Federal Center, Building 41, Denver, Colorado

    SciTech Connect

    Lee, Eleanor S.; Fernandes, Luis L.; Goudey, Chad Howdy; Jonsson, Carl Jacob; Curcija, D. Charlie; Pang, Xiufeng; DiBartolomeo, Dennis; Hoffmann, Sabine

    2013-07-01

    Chromogenic glazing materials are emerging technologies that tint reversibly from a clear to dark tinted state either passively in response to environmental conditions or actively in response to a command from a switch or building automation system. Switchable coatings on glass manage solar radiation and visible light while enabling unobstructed views to the outdoors. Building energy simulations estimate that actively controlled, near-term chromogenic glazings can reduce perimeter zone heating, ventilation, and airconditioning (HVAC) and lighting energy use by 10-20% and reduce peak electricity demand by 20-30%, achieving energy use levels that are lower than an opaque, insulated wall. This project demonstrates the use of two types of chromogenic windows: thermochromic and electrochromic windows. By 2013, these windows will begin production in the U.S. by multiple vendors at high-volume manufacturing plants, enabling lower cost and larger area window products to be specified. Both technologies are in the late R&D stage of development, where cost reductions and performance improvements are underway. Electrochromic windows have been installed in numerous buildings over the past four years, but monitored energy-efficiency performance has been independently evaluated in very limited applications. Thermochromic windows have been installed in one other building with an independent evaluation, but results have not yet been made public.

  20. Liquid phase deposition synthesis of hexagonal molybdenum trioxide thin films

    SciTech Connect

    Deki, Shigehito; Beleke, Alexis Bienvenu; Kotani, Yuki; Mizuhata, Minoru

    2009-09-15

    Hexagonal molybdenum trioxide thin films with good crystallinity and high purity have been fabricated by the liquid phase deposition (LPD) technique using molybdic acid (H{sub 2}MoO{sub 4}) dissolved in 2.82% hydrofluoric acid (HF) and H{sub 3}BO{sub 3} as precursors. The crystal was found to belong to a hexagonal hydrate system MoO{sub 3}.nH{sub 2}O (napprox0.56). The unit cell lattice parameters are a=10.651 A, c=3.725 A and V=365.997 A{sup 3}. Scanning electron microscope (SEM) images of the as-deposited samples showed well-shaped hexagonal rods nuclei that grew and where the amount increased with increase in reaction time. X-ray photon electron spectroscopy (XPS) spectra showed a Gaussian shape of the doublet of Mo 3d core level, indicating the presence of Mo{sup 6+} oxidation state in the deposited films. The deposited films exhibited an electrochromic behavior by lithium intercalation and deintercalation, which resulted in coloration and bleaching of the film. Upon dehydration at about 450 deg. C, the hexagonal MoO{sub 3}.nH{sub 2}O was transformed into the thermodynamically stable orthorhombic phase. - Abstract: SEM photograph of typical h-MoO{sub 3}.nH{sub 2}O thin film nuclei obtained after 36 h at 40 deg. C by the LPD method. Display Omitted

  1. Electrodeposition of nickel oxyhydroxide films through polymer masks

    SciTech Connect

    Yang, M.C.; Lin, C.K.; Su, C.L.

    1995-04-01

    Electrochromic materials have attracted much attention for devices including ``smart windows`` and displays. Nickel oxyhydroxide films were electrodeposited through gelatin masks, whose thicknesses may control the optical transmittances of the deposited electrochromic films. The difference of transmittance, {Delta}T{sub 540}, between bleaching and coloration states at wavelength of 540 nm has a linear relationship with the gelatin mask thickness. {Delta}T{sub 540} increased if nickel oxyhydroxide was prepared in agitated electrolyte. The electrodeposited films, prepared with gelatin masks, may have higher stability. These results showed the feasibility of fabricating an electrochromic device with a controlled image whose contrast and brightness are adjustable with potential or current.

  2. An Exploratory Energy Analysis of Electrochromic Windows in Small and Medium Office Buildings - Simulated Results Using EnergyPlus

    SciTech Connect

    Belzer, David B.

    2010-08-01

    The Department of Energy’s (DOE) Building Technologies Program (BTP) has had an active research program in supporting the development of electrochromic (EC) windows. Electrochromic glazings used in these windows have the capability of varying the transmittance of light and heat in response to an applied voltage. This dynamic property allows these windows to reduce lighting, cooling, and heating energy in buildings where they are employed. The exploratory analysis described in this report examined three different variants of EC glazings, characterized by the amount of visible light and solar heat gain (as measured by the solar heat gain coefficients [SHGC] in their “clear” or transparent states). For these EC glazings, the dynamic range of the SHGC’s between their “dark” (or tinted) state and the clear state were: (0.22 - 0.70, termed “high” SHGC); (0.16 - 0.39, termed “low” SHGC); and (0.13 - 0.19; termed “very low” SHGC). These glazings are compared to conventional (static) glazing that meets the ASHRAE Standard 90.1-2004 energy standard for five different locations in the U.S. All analysis used the EnergyPlus building energy simulation program for modeling EC windows and alternative control strategies. The simulations were conducted for a small and a medium office building, where engineering specifications were taken from the set of Commercial Building Benchmark building models developed by BTP. On the basis of these simulations, total source-level savings in these buildings were estimated to range between 2 to 7%, depending on the amount of window area and building location.

  3. GAS DISCHARGE DEVICES

    DOEpatents

    Jefferson, S.

    1958-11-11

    An apparatus utilized in introducing tritium gas into envelope of a gas discharge device for the purpose f maintaining the discharge path in ionized condition is described. ln addition to the cathode and anode, the ischarge device contains a zirconium or tantalum ilament arranged for external excitation and a metallic seed containing tritium, and also arranged to have a current passed through it. Initially, the zirconium or tantalum filament is vaporized to deposit its material adjacent the main discharge region. Then the tritium gas is released and, due to its affinity for the first released material, it deposits in the region of the main discharge where it is most effective in maintaining the discharge path in an ionized condition.

  4. Thermodynamic clarification of the curious ferric/potassium ion exchange accompanying the electrochromic redox reactions of prussian blue, iron(III) hexacyanoferrate(II).

    PubMed

    Rosseinsky, David R; Glasser, Leslie; Jenkins, H Donald Brooke

    2004-08-25

    The recent Glasser-Jenkins method for lattice-energy prediction, applied to an examination of the solid-state thermodynamics of the cation exchanges that occur in electrochromic reactions of Prussian Blue, provides incisive thermodynamic clarification of an ill-understood ion exchange that accompanies particularly the early electrochromic cycles. A volume of 0.246 +/- 0.017 nm(3) formula unit(-1) for the ferrocyanide ion, Fe(II)[(CN)(6)],(4-) is first established and then used, together with other formula unit-volume data, to evaluate the changes of standard enthalpy, entropy, and Gibbs energy in those ion-exchange reactions. The results impressively show by how much the exchange of interstitial Fe(3+) ions by alkali metal ions, usually exemplified by K+, is thermodynamically favored.

  5. Conjugated polymer network films of poly(p-phenylene vinylene) with hole-transporting carbazole pendants: dual photoluminescence and electrochromic behavior.

    PubMed

    Ponnapati, Ramakrishna; Felipe, Mary Jane; Muthalagu, Vetrichelvan; Puno, Katherine; Wolff, Birte; Advincula, Rigoberto

    2012-03-01

    A series of poly(p-phenylene vinylene) (PPV) copolymers functionalized with hole-transport and electrochemically active carbazole units as pendant moieties is reported. These polymers exhibit photoluminescence properties by virtue of the PPV analogous backbone. They were also designed as precursor polymer bearing the electroactive carbazole group to form conjugated polymer network (CPN) films by electrodeposition. The electrochemical polymerization of the pendant units eventually lead to a dual property electro-optically active thin film - photoluminescence (PL) behavior that can be attenuated with CPN formation, and a reversible doping and dedoping processes at controlled potentials that lead to an electrochromic behavior. This reveals the ability to incorporate complementary optical and electro-optical properties within the same film using the CPN approach. It should be possible to design and synthesize other PPV π-conjugated polymers with efficient pendant hole-transport groups exhibiting tunable PL and electrochromism with cross-linking. PMID:22329863

  6. Conjugated polymer network films of poly(p-phenylene vinylene) with hole-transporting carbazole pendants: dual photoluminescence and electrochromic behavior.

    PubMed

    Ponnapati, Ramakrishna; Felipe, Mary Jane; Muthalagu, Vetrichelvan; Puno, Katherine; Wolff, Birte; Advincula, Rigoberto

    2012-03-01

    A series of poly(p-phenylene vinylene) (PPV) copolymers functionalized with hole-transport and electrochemically active carbazole units as pendant moieties is reported. These polymers exhibit photoluminescence properties by virtue of the PPV analogous backbone. They were also designed as precursor polymer bearing the electroactive carbazole group to form conjugated polymer network (CPN) films by electrodeposition. The electrochemical polymerization of the pendant units eventually lead to a dual property electro-optically active thin film - photoluminescence (PL) behavior that can be attenuated with CPN formation, and a reversible doping and dedoping processes at controlled potentials that lead to an electrochromic behavior. This reveals the ability to incorporate complementary optical and electro-optical properties within the same film using the CPN approach. It should be possible to design and synthesize other PPV π-conjugated polymers with efficient pendant hole-transport groups exhibiting tunable PL and electrochromism with cross-linking.

  7. Synthesis and characterization of an electrochromic copolymer based on 2,2':5',2″-terthiophene and 3,4-ethylenedioxythiophene

    NASA Astrophysics Data System (ADS)

    Ahmed, Mohammad Shamsuddin; Jeong, Haesang; You, Jung-Min; Jeon, Seungwon

    2012-06-01

    A new electrochromic copolymer of 2,2':5',2″-terthiophene (TT) with 3,4-ethylenedioxythiophene (EDOT) was synthesized in 0.1 M tetrabutylammonium perchlorate as supporting electrolyte and characterizations of the resulting copolymer P(TT-co-EDOT) performed by cyclic voltammetry, UV-vis spectroscopy, scanning electron microscopy, fourier transform infrared spectroscopy, nuclear magnetic resonance and thermal analysis. Spectroelectrochemical investigations showed that the copolymer film has electrochromic properties. It showed five different colors at various potentials (sky blue, gray, light purple, blues violet and dark blues violet). Double potential step chronoamperometry experiment illustrated that copolymer film had good stability, fast switching time and high optical contrast. At the neutral state of the copolymer λmax was found at 500 nm and E g was calculated as 1.63 eV. The copolymer film showed a maximum optical contrast of 54% at 1,100 nm with a short response time.

  8. Photovoltaic device

    DOEpatents

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  9. Photovoltaic device

    DOEpatents

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  10. Surface Acoustic Wave Monitor for Deposition and Analysis of Ultra-Thin Films

    NASA Technical Reports Server (NTRS)

    Hines, Jacqueline H. (Inventor)

    2015-01-01

    A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.

  11. Integrated fuses for OLED lighting device

    DOEpatents

    Pschenitzka, Florian

    2007-07-10

    An embodiment of the present invention pertains to an electroluminescent lighting device for area illumination. The lighting device is fault tolerant due, in part, to the patterning of one or both of the electrodes into strips, and each of one or more of these strips has a fuse formed on it. The fuses are integrated on the substrate. By using the integrated fuses, the number of external contacts that are used is minimized. The fuse material is deposited using one of the deposition techniques that is used to deposit the thin layers of the electroluminescent lighting device.

  12. Role of salt concentration in blend polymer for energy storage conversion devices

    NASA Astrophysics Data System (ADS)

    Arya, Anil; Sadiq, M.; Sharma, A. L.

    2016-05-01

    Solid Polymer Electrolytes (SPE) are materials of considerable interest worldwide, which serves dual purpose of electrolyte and separator between electrode compartments in renewable energy conversion/storage devices such as; high energy density batteries, electrochromic display devices, and supercapacitors. Polymer blend electrolytes are prepared for various concentration of salt (Ö/Li) with the constant ratio (0.5 gm) of each PEO and PAN polymers (blend polymer) using solution casting technique. Solid polymeric ionic conductor as a separator is the ultimate substitute to eliminate the drawback related to liquid and gel polymer ionic conductors. In the present work, solid polymer electrolyte film consisting of PEO, PAN and LiPF6 are examined for various concentration of lithium salt by keeping PEO/PAN blend ratio as a constant with a view to optimize the dominant salt concentration which could give the maximum conductivity at ambient temperature.

  13. Microfluidic Device

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey (Inventor)

    2015-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  14. Microfluidic Device

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2016-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  15. Sealing device

    DOEpatents

    Garcia-Crespo, Andres Jose

    2013-12-10

    A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assemply is subjected to a centrifugal force.

  16. - History, Technology, and the Future

    NASA Astrophysics Data System (ADS)

    Lampert, C. M.

    2002-12-01

    This paper begins with the history of electrochromism, first discovered in the 1880's. The physics, electrochemistry, device design and materials are covered. The science of electrochromism involves the coloration of a variety of metal oxides, organics and polymers. Dual ion and electron intercalation is used to color and bleach electrochromic materials. Considerable science has been undertaken to make devices that resemble thin film transparent batteries in their structure. A number of materials have been developed to make layers for electrochromic devices. Applications for electrochromics include low information content displays, such as banner displays, smart windows and mirrors for automotive applications. Several companies throughout the world are developing dynamic glazing. Switchable glazing for building and vehicle application is very attractive for energy and light management. From the standpoint of materials much research and development in electrochromics focuses on the development or improvement of materials with ionic and electronic properties. Much of the work on electrochromics draws on the vast knowledge developed for advanced batteries. National Laboratory and university groups are researching new materials and processes to improve electrochromic materials. Also, much industrial work is directed towards deposition and fabrication processes for glass and possibly plastic that can make electrochromics cost effective. Plastic can yield both flexibility and weight savings for many applications. Although plastics are permeable, outgas and require lower processing temperatures, they can be more universally applied. Some developments in plastics may come from OLED sealing technology. Comparisons are made between the properties of electrochromics and other switchable technologies. Technology comparisons are made between suspended particles, polymer dispersed liquid crystals, themotropics and gas-chromics.

  17. BRAKE DEVICE

    DOEpatents

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  18. Soot Deposit Properties in Practical Flames

    SciTech Connect

    Preciado, Ignacio; Eddings, Eric G.; Sarofim, Adel F.; Dinwiddie, Ralph Barton; Porter, Wallace D; Lance, Michael J

    2009-01-01

    Soot deposition from hydrocarbon flames was investigated in order to evaluate the evolution of the deposits during the transient process of heating an object that starts with a cold metal surface that is exposed to a flame. The study focused on the fire/metal surface interface and the critical issues associated with the specification of the thermal boundaries at this interface, which include the deposition of soot on the metal surface, the chemical and physical properties of the soot deposits and their subsequent effect on heat transfer to the metal surface. A laboratory-scale device (metallic plates attached to a water-cooled sampling probe) was designed for studying soot deposition in a laminar ethylene-air premixed flame. The metallic plates facilitate the evaluation of the deposition rates and deposit characteristics such as deposit thickness, bulk density, PAH content, deposit morphology, and thermal properties, under both water-cooled and uncooled conditions. Additionally, a non-intrusive Laser Flash Technique (in which the morphology of the deposit is not modified) was used to estimate experimental thermal conductivity values for soot deposits as a function of deposition temperature (water-cooled and uncooled experiments), location within the flame and chemical characteristics of the deposits. Important differences between water-cooled and uncooled surfaces were observed. Thermophoresis dominated the soot deposition process and enhanced higher deposition rates for the water-cooled experiments. Cooler surface temperatures resulted in the inclusion of increased amounts of condensable hydrocarbons in the soot deposit. The greater presence of condensable material promoted decreased deposit thicknesses, larger deposit densities, different deposit morphologies, and higher thermal conductivities.

  19. PLASMA DEVICE

    DOEpatents

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  20. LDRD Final Report - Investigations of the impact of the process integration of deposited magnetic films for magnetic memory technologies on radiation-hardened CMOS devices and circuits - LDRD Project (FY99)

    SciTech Connect

    MYERS,DAVID R.; JESSING,JEFFREY R.; SPAHN,OLGA B.; SHANEYFELT,MARTY R.

    2000-01-01

    This project represented a coordinated LLNL-SNL collaboration to investigate the feasibility of developing radiation-hardened magnetic non-volatile memories using giant magnetoresistance (GMR) materials. The intent of this limited-duration study was to investigate whether giant magnetoresistance (GMR) materials similar to those used for magnetic tunnel junctions (MTJs) were process compatible with functioning CMOS circuits. Sandia's work on this project demonstrated that deposition of GMR materials did not affect the operation nor the radiation hardness of Sandia's rad-hard CMOS technology, nor did the integration of GMR materials and exposure to ionizing radiation affect the magnetic properties of the GMR films. Thus, following deposition of GMR films on rad-hard integrated circuits, both the circuits and the films survived ionizing radiation levels consistent with DOE mission requirements. Furthermore, Sandia developed techniques to pattern deposited GMR films without degrading the completed integrated circuits upon which they were deposited. The present feasibility study demonstrated all the necessary processing elements to allow fabrication of the non-volatile memory elements onto an existing CMOS chip, and even allow the use of embedded (on-chip) non-volatile memories for system-on-a-chip applications, even in demanding radiation environments. However, funding agencies DTRA, AIM, and DARPA did not have any funds available to support the required follow-on technology development projects that would have been required to develop functioning prototype circuits, nor were such funds available from LDRD nor from other DOE program funds.

  1. High temperature electronic gain device

    DOEpatents

    McCormick, J. Byron; Depp, Steven W.; Hamilton, Douglas J.; Kerwin, William J.

    1979-01-01

    An integrated thermionic device suitable for use in high temperature, high radiation environments. Cathode and control electrodes are deposited on a first substrate facing an anode on a second substrate. The substrates are sealed to a refractory wall and evacuated to form an integrated triode vacuum tube.

  2. Junction and Back Contact Properties of Spray-Deposited M/SnS/In2S3/SnO2:F/Glass (M = Cu, Graphite) Devices: Considerations to Improve Photovoltaic Performance

    NASA Astrophysics Data System (ADS)

    Patel, Malkeshkumar; Ray, Abhijit

    2015-01-01

    SnS/In2S3 heterojunction devices were fabricated entirely by chemical spray pyrolysis in a superstrate configuration on SnO2:F/glass. The SnS/In2S3 junction was found to exhibit strong rectification behavior, and the Mott-Schottky characteristics showed it was abrupt. The photovoltaic behavior of the junction was investigated under air mass 1.5G illumination, showing a short-circuit current of 4.8 mA/cm2 and an open-circuit voltage of 0.29 V, reportedly the highest to date among similar devices with a Cd-free buffer layer and processed by a nonvacuum technique. However, the device suffers from low fill factor due to high series resistance originating from interface inhomogeneities. A Cu back contact was associated with a low level of inhomogeneities at the interface, as demonstrated by impedance analysis.

  3. Inkjet deposited circuit components

    NASA Astrophysics Data System (ADS)

    Bidoki, S. M.; Nouri, J.; Heidari, A. A.

    2010-05-01

    All-printed electronics as a means of achieving ultra-low-cost electronic circuits has attracted great interest in recent years. Inkjet printing is one of the most promising techniques by which the circuit components can be ultimately drawn (i.e. printed) onto the substrate in one step. Here, the inkjet printing technique was used to chemically deposit silver nanoparticles (10-200 nm) simply by ejection of silver nitrate and reducing solutions onto different substrates such as paper, PET plastic film and textile fabrics. The silver patterns were tested for their functionality to work as circuit components like conductor, resistor, capacitor and inductor. Different levels of conductivity were achieved simply by changing the printing sequence, inks ratio and concentration. The highest level of conductivity achieved by an office thermal inkjet printer (300 dpi) was 5.54 × 105 S m-1 on paper. Inkjet deposited capacitors could exhibit a capacitance of more than 1.5 nF (parallel plate 45 × 45 mm2) and induction coils displayed an inductance of around 400 µH (planar coil 10 cm in diameter). Comparison of electronic performance of inkjet deposited components to the performance of conventionally etched items makes the technique highly promising for fabricating different printed electronic devices.

  4. Photochromic and electrochromic performances of new types of donor/acceptor systems based on crosslinked polyviologen film and electron donors

    NASA Astrophysics Data System (ADS)

    Gao, Li-ping; Ding, Guo-jing; Li, Chao-long; Wang, Yue-chuan

    2011-01-01

    Viologen-functionalized copolymer COPV2+ was synthesized by copolymer graft-modified, which was crosslinked by NH3·H2O gas-fumigated at 25 °C for 4 h due to the condensation of the siloxanes of COPV2+ film. Simultaneously, different donor/acceptor systems had been prepared based on crosslinked polyviologen film (COPV2+) and N,N,N‧,N‧-tetramethyl-1,4-phenylenediamine (TMPD) or hydroxyethylferrocene (HEFc) in order to shorten the response times and improve contrast ratios in response to external photo- and potential stimuli. The evolution of structures from COPO to COPV2+ is carefully characterized. The COPV2+/TMPD and COPV2+/HEFc films exhibited both photochromic and electrochromic performances. After UV irradiations, COPV2+/TMPD and COPV2+/HEFc films changed their colors from colorless to deep blue, while optical transmissions at 610 nm decreased about 64% and 75%, respectively. When removing out from UV irradiation, the colored COPV2+/TMPD and COPV2+/HEFc films faded to the original colors within about 60 min. When COPV2+/TMPD and COPV2+/HEFc films were biased with negative voltage of -2.5 V, they changed their colors from colorless to deep blue in 4 s and 3 s, while the optical transmissions at 556 nm decreased about 81% and 75%, respectively. When electric impulse was switched off, the colored COPV2+/TMPD and COPV2+/HEFc films faded to the original colors within about 7 s and 6 s, respectively.

  5. Ionic liquids effects on the permeability of photosynthetic membranes probed by the electrochromic shift of endogenous carotenoids.

    PubMed

    Malferrari, Marco; Malferrari, Danilo; Francia, Francesco; Galletti, Paola; Tagliavini, Emilio; Venturoli, Giovanni

    2015-11-01

    Ionic liquids (ILs) are promising materials exploited as solvents and media in many innovative applications, some already used at the industrial scale. The chemical structure and physicochemical properties of ILs can differ significantly according to the specific applications for which they have been synthesized. As a consequence, their interaction with biological entities and toxicity can vary substantially. To select highly effective and minimally harmful ILs, these properties need to be investigated. Here we use the so called chromatophores--protein-phospholipid membrane vesicles obtained from the photosynthetic bacterium Rhodobacter sphaeroides--to assess the effects of imidazolinium and pyrrolidinium ILs, with chloride or dicyanamide as counter anions, on the ionic permeability of a native biological membrane. The extent and modalities by which these ILs affect the ionic conductivity can be studied in chromatophores by analyzing the electrochromic response of endogenous carotenoids, acting as an intramembrane voltmeter at the molecular level. We show that chromatophores represent an in vitro experimental model suitable to probe permeability changes induced in cell membranes by ILs differing in chemical nature, degree of oxygenation of the cationic moiety and counter anion.

  6. Multistate Redox Switching and Near-Infrared Electrochromism Based on a Star-Shaped Triruthenium Complex with a Triarylamine Core

    NASA Astrophysics Data System (ADS)

    Tang, Jian-Hong; He, Yan-Qin; Shao, Jiang-Yang; Gong, Zhong-Liang; Zhong, Yu-Wu

    2016-10-01

    A star-shaped cyclometalated triruthenium complex 2(PF6)n (n = 3 and 4) with a triarylamine core was synthesized, which functions as a molecular switch with five well-separated redox states in both solution and film states. The single-crystal X-ray structure of 2(PF6)3 is presented. This complex displays four consecutive one-electron redox waves at +0.082, +0.31, +0.74, and +1.07 V vs Ag/AgCl. In each redox state, it shows significantly different NIR absorptions with λmax of 1590 nm for 24+, 1400 nm for 25+, 1060 nm for 26+, and 740 nm for 27+, respectively. Complex 24+ shows a single-line EPR signal at g = 2.060, while other redox states are all EPR inactive. The spin density distributions and NIR absorptions in different redox states were rationalized by DFT and TDDFT calculations. A vinyl-substituted triruthenium analogous 3(PF6)4 was prepared, which was successfully polymerized on ITO glass electrode surfaces by reductive electropolymerization. The obtained poly-3n+/ITO film was characterized by FTIR, AFM, and SEM analysis. It shows four well-defined redox couples and reversible multistate NIR electrochromism. In particular, a contrast ratio (ΔT%) up to 63% was achieved at the optic telecommunication wavelength (1550 nm).

  7. Aerosol-jet-printed, 1 volt H-bridge drive circuit on plastic with integrated electrochromic pixel.

    PubMed

    Ha, Mingjing; Zhang, Wei; Braga, Daniele; Renn, Michael J; Kim, Chris H; Frisbie, C Daniel

    2013-12-26

    In this report, we demonstrate a printed, flexible, and low-voltage circuit that successfully drives a polymer electrochromic (EC) pixel as large as 4 mm(2) that is printed on the same substrate. All of the key components of the drive circuitry, namely, resistors, capacitors, and transistors, were aerosol-jet-printed onto a plastic foil; metallic electrodes and interconnects were the only components prepatterned on the plastic by conventional photolithography. The large milliampere drive currents necessary to switch a 4 mm(2) EC pixel were controlled by printed electrolyte-gated transistors (EGTs) that incorporate printable ion gels for the gate insulator layers and poly(3-hexylthiophene) for the semiconductor channels. Upon application of a 1 V input pulse, the circuit switches the printed EC pixel ON (red) and OFF (blue) two times in approximately 4 s. The performance of the circuit and the behavior of the individual resistors, capacitors, EGTs, and the EC pixel are analyzed as functions of the printing parameters and operating conditions.

  8. A Resettable Keypad Lock with Visible Readout Based on Closed Bipolar Electrochemistry and Electrochromic Poly(3-methylthiophene) Films.

    PubMed

    Wang, Lei; Lian, Wenjing; Liu, Hongyun

    2016-03-24

    A closed bipolar electrode (BPE) system was developed with electrochromic poly(3-methylthiophene) (PMT) films electropolymerized on the ITO/rGO electrode as one pole of BPE in the reporting reservoir and the bare ITO electrode as another pole of BPE in the analyte reservoir, in which rGO represents reduced graphene oxide. Under a suitable driving voltage (Vtot), the electrochemical reduction/oxidation of electroactive probes, such as H2O2/glutathione (Glu), in the analyte reservoir could induce the reversible color change of PMT films in the reporting reservoir between blue and red. Based on this, a keypad lock with H2O2 , Glu, and Vtot =-3.0 V as the three inputs and the color change of PMT films as the visible output was established. This system was easily operated and did not need to synthesize the complex compounds or DNA molecules. The security system was easy to reset and could be used repeatedly.

  9. Composite WO3/TiO2 nanostructures for high electrochromic activity

    SciTech Connect

    Reyes-Gil, Karla R.; Stephens, Zachary D.; Stavila, Vitalie; Robinson, David B.

    2015-01-06

    A composite material consisting of TiO2 nanotubes (NT) with WO3 electrodeposited on its surface has been fabricated, detached from its Ti substrate, and attached to a fluorine-doped tin oxide (FTO) film on glass for application to electrochromic (EC) reactions. Several adhesion layers were tested, finding that a paste of TiO2 made from commercially available TiO2 nanoparticles creates an interface for the TiO2 NT film to attach to the FTO glass, which is conductive and does not cause solution-phase ions in an electrolyte to bind irreversibly with the material. The effect of NT length and WO3 concentration on the EC performance were studied. As a result, the composite WO3/TiO2 nanostructures showed higher ion storage capacity, better stability, enhanced EC contrast, and longer memory time compared with the pure WO3 and TiO2 materials

  10. Multistate Redox Switching and Near-Infrared Electrochromism Based on a Star-Shaped Triruthenium Complex with a Triarylamine Core

    PubMed Central

    Tang, Jian-Hong; He, Yan-Qin; Shao, Jiang-Yang; Gong, Zhong-Liang; Zhong, Yu-Wu

    2016-01-01

    A star-shaped cyclometalated triruthenium complex 2(PF6)n (n = 3 and 4) with a triarylamine core was synthesized, which functions as a molecular switch with five well-separated redox states in both solution and film states. The single-crystal X-ray structure of 2(PF6)3 is presented. This complex displays four consecutive one-electron redox waves at +0.082, +0.31, +0.74, and +1.07 V vs Ag/AgCl. In each redox state, it shows significantly different NIR absorptions with λmax of 1590 nm for 24+, 1400 nm for 25+, 1060 nm for 26+, and 740 nm for 27+, respectively. Complex 24+ shows a single-line EPR signal at g = 2.060, while other redox states are all EPR inactive. The spin density distributions and NIR absorptions in different redox states were rationalized by DFT and TDDFT calculations. A vinyl-substituted triruthenium analogous 3(PF6)4 was prepared, which was successfully polymerized on ITO glass electrode surfaces by reductive electropolymerization. The obtained poly-3n+/ITO film was characterized by FTIR, AFM, and SEM analysis. It shows four well-defined redox couples and reversible multistate NIR electrochromism. In particular, a contrast ratio (ΔT%) up to 63% was achieved at the optic telecommunication wavelength (1550 nm). PMID:27731404

  11. Silicon carbide and other films and method of deposition

    NASA Technical Reports Server (NTRS)

    Mehregany, Mehran (Inventor); Zorman, Christian A. (Inventor); Fu, Xiao-An (Inventor); Dunning, Jeremy L. (Inventor)

    2007-01-01

    A method of depositing a ceramic film, particularly a silicon carbide film, on a substrate is disclosed in which the residual stress, residual stress gradient, and resistivity are controlled. Also disclosed are substrates having a deposited film with these controlled properties and devices, particularly MEMS and NEMS devices, having substrates with films having these properties.

  12. Silicon carbide and other films and method of deposition

    NASA Technical Reports Server (NTRS)

    Mehregany, Mehran (Inventor); Zorman, Christian A. (Inventor); Fu, Xiao-An (Inventor); Dunning, Jeremy (Inventor)

    2011-01-01

    A method of depositing a ceramic film, particularly a silicon carbide film, on a substrate is disclosed in which the residual stress, residual stress gradient, and resistivity are controlled. Also disclosed are substrates having a deposited film with these controlled properties and devices, particularly MEMS and NEMS devices, having substrates with films having these properties.

  13. Method of and apparatus for determining deposition-point temperature

    DOEpatents

    Mansure, A.J.; Spates, J.J.; Martin, S.J.

    1998-10-27

    Acoustic-wave sensor apparatus and method are disclosed for analyzing a normally liquid petroleum-based composition for monitoring deposition-point temperature. The apparatus includes at least one acoustic-wave device such as SAW, QCM, FPM, TSM or APM type devices in contact with the petroleum-based composition for sensing or detecting the surface temperature at which deposition occurs and/or rate of deposition as a function of temperature by sensing an accompanying change in frequency, phase shift, damping voltage or damping current of an electrical oscillator to a known calibrated condition. The acoustic wave device is actively cooled to monitor the deposition of constituents such as paraffins by determining the point at which solids from the liquid composition begin to form on the acoustic wave device. The acoustic wave device can be heated to melt or boil off the deposits to reset the monitor and the process can be repeated. 5 figs.

  14. Method of and apparatus for determining deposition-point temperature

    DOEpatents

    Mansure, Arthur J.; Spates, James J.; Martin, Stephen J.

    1998-01-01

    Acoustic-wave sensor apparatus and method for analyzing a normally liquid petroleum-based composition for monitoring deposition-point temperature. The apparatus includes at least one acoustic-wave device such as SAW, QCM, FPM, TSM or APM type devices in contact with the petroleum-based composition for sensing or detecting the surface temperature at which deposition occurs and/or rate of deposition as a function of temperature by sensing an accompanying change in frequency, phase shift, damping voltage or damping current of an electrical oscillator to a known calibrated condition. The acoustic wave device is actively cooled to monitor the deposition of constituents such as paraffins by determining the point at which solids from the liquid composition begin to form on the acoustic wave device. The acoustic wave device can be heated to melt or boil off the deposits to reset the monitor and the process can be repeated.

  15. Aerosol assisted chemical vapour deposition control parameters for selective deposition of tungsten oxide nanostructures.

    PubMed

    Vallejos, S; Umek, P; Blackman, C

    2011-09-01

    Tungsten oxide films were deposited via Aerosol Assisted Chemical Vapour Deposition (AACVD) from the single-source precursor W(OPh)6. Film morphology and optimum deposition temperatures for formation of quasi-one-dimensional structures is influenced by the solvent 'carrier' used for deposition of the films with bulk porous films and nanostructured needles, hollow tubes and fibres obtained dependent on the solvent used and the deposition temperature. This influence of solvent could be exploited for the synthesis of other nanomaterials, and so provide a new and versatile route to develop and integrate nanostructured materials for device applications. PMID:22097557

  16. Micro devices using shape memory polymer patches for mated connections

    DOEpatents

    Lee, Abraham P.; Fitch, Joseph P.

    2000-01-01

    A method and micro device for repositioning or retrieving miniature devices located in inaccessible areas, such as medical devices (e.g., stents, embolic coils, etc.) located in a blood vessel. The micro repositioning or retrieving device and method uses shape memory polymer (SMP) patches formed into mating geometries (e.g., a hoop and a hook) for re-attachment of the deposited medical device to a catheter or guidewire. For example, SMP or other material hoops are formed on the medical device to be deposited in a blood vessel, and SMP hooks are formed on the micro device attached to a guidewire, whereby the hooks on the micro device attach to the hoops on the medical device, or vice versa, enabling deposition, movement, re-deposit, or retrieval of the medical device. By changing the temperature of the SMP hooks, the hooks can be attached to or released from the hoops located on the medical device. An exemplary method for forming the hooks and hoops involves depositing a sacrificial thin film on a substrate, patterning and processing the thin film to form openings therethrough, depositing or bonding SMP materials in the openings so as to be attached to the substrate, and removing the sacrificial thin film.

  17. Metal-Film Hall-Effect Devices

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.

    1994-01-01

    Large positive and negative Hall coefficients achievable. Family of Hall-effect devices made from multilayer metal films instead of semiconductor materials. Metal films easier to fabricate; formed by deposition on variety of substrates, and leads readily attached to them. Fabricated with larger areas, potentially more reliable, and less affected by impurities. Also used to measure magnetic fields. Devices especially useful at low temperatures.

  18. PLASMA DEVICE

    DOEpatents

    Baker, W.R.; Brathenahl, A.; Furth, H.P.

    1962-04-10

    A device for producing a confined high temperature plasma is described. In the device the concave inner surface of an outer annular electrode is disposed concentrically about and facing the convex outer face of an inner annular electrode across which electrodes a high potential is applied to produce an electric field there between. Means is provided to create a magnetic field perpendicular to the electric field and a gas is supplied at reduced pressure in the area therebetween. Upon application of the high potential, the gas between the electrodes is ionized, heated, and under the influence of the electric and magnetic fields there is produced a rotating annular plasma disk. The ionized plasma has high dielectric constant properties. The device is useful as a fast discharge rate capacitor, in controlled thermonuclear research, and other high temperature gas applications. (AEC)

  19. In-situ observation of self-regulated switching behavior in WO{sub 3-x} based resistive switching devices

    SciTech Connect

    Hong, D. S.; Wang, W. X.; Chen, Y. S. Sun, J. R.; Shen, B. G.

    2014-09-15

    The transmittance of tungsten oxides can be adjusted by oxygen vacancy (V{sub o}) concentration due to its electrochromic property. Here, we report an in-situ observation of resistive switching phenomenon in the oxygen-deficient WO{sub 3-x} planar devices. Besides directly identifying the formation/rupture of dark-colored conductive filaments in oxide layer, the stripe-like WO{sub 3-x} device demonstrated self-regulated switching behavior during the endurance testing, resulting in highly consistent switching parameters after a stabilizing process. For very high V{sub o}s mobility was demonstrated in the WO{sub 3-x} film by the pulse experiment, we suggested that the electric-field-induced homogeneous migration of V{sub o}s was the physical origin for such unique switching characteristics.

  20. Medical Device Safety

    MedlinePlus

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