National Library of Energy BETA

Sample records for ant-eden ald en-lanc


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    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    BOE Reserve Class No 2001 reserves 0.1 - 10 MBOE 10.1 - 100 MBOE 100.1 - 1000 MBOE 1000.1 - 10,000 MBOE 10,000.1 - 100,000 MBOE > 100,000 MBOE Appalachian Basin Boundary C a n a d a N Y P A N Y U S A Appalachian Basin, NY Area (Panel 1 of 7) Oil and Gas Fields By 2001 BOE


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    Liquids Reserve Class No 2001 Liiquids Reserves 0.1 - 10 Mbbl 10.1 - 100 Mbbl 100.1 - 1000 Mbbl 1000.1 - 10,000 Mbbl Appalachian Basin Boundary C a n a d a N Y P A N Y U S A Appalachian Basin, NY Area (Panel 1 of 7) Oil and Gas Fields By 2001 Liquids

  4. ALD Nanosolutions | Open Energy Information

    Open Energy Info (EERE)

    ALD Nanosolutions was selected as one of 8 companies to receive a small business innovation grant from the U.S. Department of Energy. They received 150,00 for development of a...

  5. Atomic Layer Deposition (ALD) Preparation of Noble Metal Catalysts - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Innovation Portal Hydrogen and Fuel Cell Hydrogen and Fuel Cell Energy Storage Energy Storage Advanced Materials Advanced Materials Find More Like This Return to Search Atomic Layer Deposition (ALD) Preparation of Noble Metal Catalysts Applications in fuel cells, batteries, environmental remediation, water treatment and catalytic reforming for fuel production. University of Colorado Contact CU About This Technology Publications: PDF Document Publication CU2465B (ALD Catalyst) Marketing

  6. Cathodic ALD V2O5 thin films for high-rate electrochemical energy...

    Office of Scientific and Technical Information (OSTI)

    Cathodic ALD V2O5 thin films for high-rate electrochemical energy storage Citation Details In-Document Search Title: Cathodic ALD V2O5 thin films for high-rate electrochemical ...

  7. Final Report: Novel ALD-Coated Nanoparticle Anodes for Enhanced Performance Lithium-Ion Batteries

    SciTech Connect (OSTI)

    Groner, Markus


    The Phase I effort is described in detail in the Phase I report given below. The key accomplishments of the Phase I project were (1) the demonstration of high stability LiCoO2 cathodes using ALD-coated LiCoO2 particles, as well as on ALD-coated LiCoO2 electrodes and (2) the demonstration of high stability of graphite anodes using ALD-coated graphite electrodes.

  8. Cathodic ALD V2O5 thin films for high-rate electrochemical energy storage

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Cathodic ALD V2O5 thin films for high-rate electrochemical energy storage Citation Details In-Document Search Title: Cathodic ALD V2O5 thin films for high-rate electrochemical energy storage Authors: Chen, X ; Pomerantseva, Ekaterina ; Gregorczyk, Keith ; Ghodssi, Reza ; Rubloff, Gary W Publication Date: 2013-01-01 OSTI Identifier: 1105360 DOE Contract Number: SC0001160 Resource Type: Journal Article Resource Relation: Journal Name: RSC Advances; Journal

  9. ALD Functionalized Nanoporous Gold: Thermal Stability, Mechanical Properties, and Catalytic Activity

    SciTech Connect (OSTI)

    Biener, M M; Biener, J; Wichmann, A; Wittstock, A; Baumann, T F; Baeumer, M; Hamza, A V


    Nanoporous metals have many technologically promising applications but their tendency to coarsen limits their long-term stability and excludes high temperature applications. Here, we demonstrate that atomic layer deposition (ALD) can be used to stabilize and functionalize nanoporous metals. Specifically, we studied the effect of nanometer-thick alumina and titania ALD films on thermal stability, mechanical properties, and catalytic activity of nanoporous gold (np-Au). Our results demonstrate that even only one-nm-thick oxide films can stabilize the nanoscale morphology of np-Au up to 1000 C, while simultaneously making the material stronger and stiffer. The catalytic activity of np-Au can be drastically increased by TiO{sub 2} ALD coatings. Our results open the door to high temperature sensor, actuator, and catalysis applications and functionalized electrodes for energy storage and harvesting applications.

  10. ALD of Al2O3 for Highly Improved Performance in Li-Ion Batteries

    SciTech Connect (OSTI)

    Dillon, A.; Jung, Y. S.; Ban, C.; Riley, L.; Cavanagh, A.; Yan, Y.; George, S.; Lee, S. H.


    Significant advances in energy density, rate capability and safety will be required for the implementation of Li-ion batteries in next generation electric vehicles. We have demonstrated atomic layer deposition (ALD) as a promising method to enable superior cycling performance for a vast variety of battery electrodes. The electrodes range from already demonstrated commercial technologies (cycled under extreme conditions) to new materials that could eventually lead to batteries with higher energy densities. For example, an Al2O3 ALD coating with a thickness of ~ 8 A was able to stabilize the cycling of unexplored MoO3 nanoparticle anodes with a high volume expansion. The ALD coating enabled stable cycling at C/2 with a capacity of ~ 900 mAh/g. Furthermore, rate capability studies showed the ALD-coated electrode maintained a capacity of 600 mAh/g at 5C. For uncoated electrodes it was only possible to observe stable cycling at C/10. Also, we recently reported that a thin ALD Al2O3 coating with a thickness of ~5 A can enable natural graphite (NG) electrodes to exhibit remarkably durable cycling at 50 degrees C. The ALD-coated NG electrodes displayed a 98% capacity retention after 200 charge-discharge cycles. In contrast, bare NG showed a rapid decay. Additionally, Al2O3 ALD films with a thickness of 2 to 4 A have been shown to allow LiCoO2 to exhibit 89% capacity retention after 120 charge-discharge cycles performed up to 4.5 V vs Li/Li+. Bare LiCoO2 rapidly deteriorated in the first few cycles. The capacity fade is likely caused by oxidative decomposition of the electrolyte at higher potentials or perhaps cobalt dissolution. Interestingly, we have recently fabricated full cells of NG and LiCoO2 where we coated both electrodes, one or the other electrode as well as neither electrode. In creating these full cells, we observed some surprising results that lead us to obtain a greater understanding of the ALD coatings. We have also recently coated a binder free LiNi0.04Mn0.04Co02O2 electrode containing 5 wt% single-walled carbon nanotubes as the conductive additive and demonstrated both high rate capability as well as the ability to cycle the cathode to 5 V vrs. Li/Li+. Finally, we coated a Celgard (TM) separator and enabled stable cycling in a high dielectric electrolyte. These results will be presented in detail.

  11. ALD Produced B{sub 2}O{sub 3}, Al{sub 2}O{sub 3} and TiO{sub 2} Coatings on Gd{sub 2}O{sub 3} Burnable Poison Nanoparticles and Carbonaceous TRISO Coating Layers

    SciTech Connect (OSTI)

    Weimer, Alan


    This project will demonstrate the feasibility of using atomic layer deposition (ALD) to apply ultrathin neutron-absorbing, corrosion-resistant layers consisting of ceramics, metals, or combinations thereof, on particles for enhanced nuclear fuel pellets. Current pellet coating technology utilizes chemical vapor deposition (CVD) in a fluidized bed reactor to deposit thick, porous layers of C (or PyC) and SiC. These graphitic/carbide materials degrade over time owing to fission product bombardment, active oxidation, thermal management issues, and long-term irradiation effects. ALD can be used to deposit potential ceramic barrier materials of interest, including ZrO{sub 2}, Y{sub 2}O{sub 3}:ZrO{sub 2} (YSZ), Al{sub 2}O{sub 3}, and TiO{sub 2}, or neutron-absorbing materials, namely B (in BN or B{sub 2}O{sub 3}) and Gd (in Gd{sub 2}O{sub 3}). This project consists of a two-pronged approach to integrate ALD into the next-generation nuclear plant (NGNP) fuel pellet manufacturing process:

  12. ALD Vacuum Technologies GmbH | Open Energy Information

    Open Energy Info (EERE)

    vacuum process equipment, including polycrystalline silicon furnaces for PV feedstock recycling. Coordinates: 50.135387, 8.916574 Show Map Loading map... "minzoom":false,"mapp...

  13. Impact of ALD Coating on Li/Mn-rich Cathode Materials

    Broader source: [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting


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    ... Pliufi aqi ui JHDDO 04 pajoadxa si 661 u pueuiap CDHO u qiMOJ aqj jo juaojad gg uBqi ajopM '(Z 31

  15. Environmental Management Directorate Fiscal Year 2000 Budget Submittal (FY00-02) Michael Schlender, EM ALD March 6, 2000

    Office of Environmental Management (EM)

    Brookhaven Science Associates U.S. Department of Energy Brookhaven Graphite Research Reactor Workshop May 9 and 10, 2007 Brookhaven Science Associates U.S. Department of Energy 2 BGRR Location at BNL BGRR Location at BNL BGRR Location at BNL BGRR Location at BNL Brookhaven Science Associates U.S. Department of Energy BGRR Complex BGRR Complex Brookhaven Science Associates U.S. Department of Energy 4 BGRR General Background BGRR General Background  First reactor built for peacetime research on

  16. Resistive switching characteristics of polycrystalline SrTiO{sub 3} films

    SciTech Connect (OSTI)

    Jong Choi, Hyung; Won Park, Suk; Deok Han, Gwon; Hyung Shim, Joon; Na, Junhong; Kim, Gyu-Tae


    Strontium titanate (STO) thin films 90?nm in thickness were grown on a Pt substrate through atomic layer deposition (ALD). The as-deposited ALD STO grown with an ALD cycle ratio of 1:1 (Sr:Ti) was in an amorphous phase, and annealing at 800?C in air crystallized the films into the perovskite phase. This phase change was confirmed by x-ray diffraction and transmission electron microscopy. The as-deposited ALD STO exhibited no discernible switching mechanism, whereas unipolar switching behavior was reproducibly observed with a high resistance ratio (10{sup 8}10{sup 9}) and strict separation of the set/reset voltages and currents in the annealed ALD STO. Mechanisms for charge transport in both the low- and high-resistance states and for resistive switching in the annealed ALD STO are also proposed.

  17. Solid flexible electrochemical supercapacitor using Tobacco mosaic virus

    Office of Scientific and Technical Information (OSTI)

    nanostructures and ALD ruthenium oxide (Journal Article) | SciTech Connect Solid flexible electrochemical supercapacitor using Tobacco mosaic virus nanostructures and ALD ruthenium oxide Citation Details In-Document Search Title: Solid flexible electrochemical supercapacitor using Tobacco mosaic virus nanostructures and ALD ruthenium oxide Authors: Gnerlich, Markus ; Pomerantseva, Ekaterina ; Gregorczyk, Keith ; Ketchum, D ; Rubloff, Gary W ; Ghodssi, Reza Publication Date: 2013-10-24 OSTI

  18. Picosun | Open Energy Information

    Open Energy Info (EERE)

    We develop and manufacture Atomic Layer Deposition (ALD) reactors for micro- and nanotechnology applications. References: Picosun1 This article is a stub. You can help OpenEI...

  19. Solid flexible electrochemical supercapacitor using Tobacco mosaic...

    Office of Scientific and Technical Information (OSTI)

    mosaic virus nanostructures and ALD ruthenium oxide Citation Details In-Document Search Title: Solid flexible electrochemical supercapacitor using Tobacco mosaic virus ...

  20. A non-destructive method for measuring the mechanical properties of ultrathin films prepared by atomic layer deposition

    SciTech Connect (OSTI)

    Zhang, Qinglin; Xiao, Xingcheng Verbrugge, Mark W.; Cheng, Yang-Tse


    The mechanical properties of ultrathin films synthesized by atomic layer deposition (ALD) are critical for the liability of their coated devices. However, it has been a challenge to reliably measure critical properties of ALD films due to the influence from the substrate. In this work, we use the laser acoustic wave (LAW) technique, a non-destructive method, to measure the elastic properties of ultrathin Al{sub 2}O{sub 3} films by ALD. The measured properties are consistent with previous work using other approaches. The LAW method can be easily applied to measure the mechanical properties of various ALD thin films for multiple applications.

  1. Institute for Atom-Efficient Chemical Transformations - Materials...

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    of which are crucial for evaluating performance in the proverbial vacuum. Using atomic layer deposition (ALD), researchers can create highly specific nanobowls, controlling...

  2. Atomic Layer Deposition | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Layer Deposition New nanophase thin film materials with properties tailored to specifically meet the needs of industry New software simulates ALD over multiple length scale,...

  3. Diane Rodi | Argonne Leadership Computing Facility

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    Diane Rodi ALD ESH/QA Coordinator Argonne National Laboratory 9700 S. Cass Avenue Building 240 - Rm. 4125 Argonne, IL 60439 630-252-1617 drodi@anl

  4. Ruthenium / aerogel nanocomposits via Atomic Layer Deposition

    SciTech Connect (OSTI)

    Biener, J; Baumann, T F; Wang, Y; Nelson, E J; Kucheyev, S O; Hamza, A V; Kemell, M; Ritala, M; Leskela, M


    We present a general approach to prepare metal/aerogel nanocomposites via template directed atomic layer deposition (ALD). In particular, we used a Ru ALD process consisting of alternating exposures to bis(cyclopentadienyl)ruthenium (RuCp{sub 2}) and air at 350 C to deposit metallic Ru nanoparticles on the internal surfaces of carbon and silica aerogels. The process does not affect the morphology of the aerogel template and offers excellent control over metal loading by simply adjusting the number of ALD cycles. We also discuss the limitations of our ALD approach, and suggest ways to overcome these.

  5. Emissions

    Office of Scientific and Technical Information (OSTI)

    ... combined with increased R&D on solar energy production ... and lt,tztstry, Organization for Economic Cooperation ... Journal of the Air ald Waste Managemert Association ...

  6. Precise Application of Transparent Conductive Oxide Coatings...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (TCO) coatings are deposited using atomic layer deposition (ALD). Provides uniform coating of complex, 3D nanostructures such as electrodes for next-generation PV cells...

  7. News Item

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    with nanoscale materials. This talk will describe research on nanoscale materials for solar photovoltaics and solar fuel production. Atomic layer deposition (ALD) is used to...

  8. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

    SciTech Connect (OSTI)

    Wu, Weibin; Institutes of Biomedical Science, Fudan University, Shanghai 200032 ; Zhu, Bo; Peng, Xiaomin; Zhou, Meiling; Jia, Dongwei; Gu, Jianxin; Institutes of Biomedical Science, Fudan University, Shanghai 200032


    Highlights: FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR attenuated alcohol-induced liver injury and steatosis. Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.

  9. Atomic Layer Deposition for the Conformal Coating of Nanoporous Materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Elam, Jeffrey W.; Xiong, Guang; Han, Catherine Y.; Wang, H. Hau; Birrell, James P.; Welp, Ulrich; Hryn, John N.; Pellin, Michael J.; Baumann, Theodore F.; Poco, John F.; et al


    Amore » tomic layer deposition ( ALD ) is ideal for applying precise and conformal coatings over nanoporous materials. We have recently used ALD to coat two nanoporous solids: anodic aluminum oxide ( AAO ) and silica aerogels. AAO possesses hexagonally ordered pores with diameters d ∼ 40 nm and pore length L ∼ 70 microns. The AAO membranes were coated by ALD to fabricate catalytic membranes that demonstrate remarkable selectivity in the oxidative dehydrogenation of cyclohexane. Additional AAO membranes coated with ALD Pd films show promise as hydrogen sensors. Silica aerogels have the lowest density and highest surface area of any solid material. Consequently, these materials serve as an excellent substrate to fabricate novel catalytic materials and gas sensors by ALD .« less

  10. On the physical and chemical details of alumina atomic layer deposition: A combined experimental and numerical approach

    SciTech Connect (OSTI)

    Pan, Dongqing; Ma, Lulu; Xie, Yuanyuan; Yuan, Chris; Jen, Tien Chien


    Alumina thin film is typically studied as a model atomic layer deposition (ALD) process due to its high dielectric constant, high thermal stability, and good adhesion on various wafer surfaces. Despite extensive applications of alumina ALD in microelectronics industries, details on the physical and chemical processes are not yet well understood. ALD experiments are not able to shed adequate light on the detailed information regarding the transient ALD process. Most of current numerical approaches lack detailed surface reaction mechanisms, and their results are not well correlated with experimental observations. In this paper, the authors present a combined experimental and numerical study on the details of flow and surface reactions in alumina ALD using trimethylaluminum and water as precursors. Results obtained from experiments and simulations are compared and correlated. By experiments, growth rate on five samples under different deposition conditions is characterized. The deposition rate from numerical simulation agrees well with the experimental results. Details of precursor distributions in a full cycle of ALD are studied numerically to bridge between experimental observations and simulations. The 3D transient numerical model adopts surface reaction kinetics and mechanisms based on atomic-level studies to investigate the surface deposition process. Surface deposition is shown as a strictly self-limited process in our numerical studies. ALD is a complex strong-coupled fluid, thermal and chemical process, which is not only heavily dependent on the chemical kinetics and surface conditions but also on the flow and material distributions.

  11. Palladium catalysts synthesized by atomic layer deposition for methanol decomposition.

    SciTech Connect (OSTI)

    Elam, J. W.; Feng, H.; Stair, P. C.; Libera, J. A.; Setthapun, W.; Northwestern Univ.


    Atomic layer deposition (ALD) palladium films were deposited at 200 C on various ALD metal oxide surfaces using sequential exposures to Pd(II) hexafluoroacetylacetonate (Pd(hfac)2) and formalin. In situ quartz crystal microbalance measurements as well as ex situ measurements performed on planar substrates revealed that the Pd growth begins with a relatively slow nucleation process and accelerates once an adequate amount of Pd has deposited on the surface. Furthermore, the Pd nucleation is faster on ALD ZnO surfaces compared to ALD Al2O3 surfaces. ALD was utilized to synthesize highly dispersed, uniform Pd nanoparticles (1 to 2 nm in diameter) on ALD ZnO and Al2O3 coated mesoporous silica gel, and the catalytic performances of these samples were compared in the methanol decomposition reaction. The ALD Pd-Al2O3 showed high activity and hydrogen selectivity at relatively low temperatures while the ALD Pd-ZnO showed very low activity as well as quick deactivation. In situ extended X-ray absorption fine structure (EXAFS) measurement revealed that the Pd supported on ZnO 'dissolves' into the substrate during the methanol decomposition reaction which accounts for the gradual disappearance of its catalytic activity. By applying one cycle of ALD Al2O3 on top of the Pd-ZnO catalyst, the activity was enhanced and the catalyst deactivation was mitigated. This Al2O3 overcoating method stabilizes the Pd-ZnO and effectively prevents the dissolution of Pd into the ZnO substrate.

  12. Atomic Layer Deposition of L-Alanine Polypeptide

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fu, Yaqin; Li, Binsong; Jiang, Ying-Bing; Dunphy, Darren R.; Tsai, Andy; Tam, Siu-Yue; Fan, Hongyou Y.; Zhang, Hongxia; Rogers, David; Rempe, Susan; et al


    L-Alanine polypeptide thin films were synthesized via atomic layer deposition (ALD). Rather, instead of using an amino acid monomer as the precursor, an L-alanine amino acid derivatized with a protecting group was used to prevent self-polymerization, increase the vapor pressure, and allow linear cycle-by-cycle growth emblematic of ALD. Moreover, the successful deposition of a conformal polypeptide film has been confirmed by FTIR, TEM, and Mass Spectrometry, and the ALD process has been extended to polyvaline.

  13. In situ study of atomic layer deposition Al{sub 2}O{sub 3} on GaP (100)

    SciTech Connect (OSTI)

    Dong, H.; Brennan, B.; Qin, X.; Hinkle, C. L.; Kim, J.; Wallace, R. M.; Zhernokletov, D. M.


    The interfacial chemistry of atomic layer deposition (ALD) of Al{sub 2}O{sub 3} on chemically treated GaP (100) has been studied using in situ X-ray photoelectron spectroscopy. A “self-cleaning” effect for Ga-oxide upon exposure to trimethylaluminum is seen to be efficient on the native oxide and chemically treated surfaces. The phosphorus oxide chemical states are seen to change during the ALD process, but the total concentration of P-oxides is seen to remain constant throughout the ALD process.

  14. Surface smoothing effect of an amorphous thin film deposited by atomic layer deposition on a surface with nano-sized roughness

    SciTech Connect (OSTI)

    Lau, W. S. Wan, X.; Xu, Y.; Wong, H.; Zhang, J.; Luo, J. K.; Institute of Renewable Energy and Environment Technology, Bolton University, Deane Road, Bolton BL3 5 AB


    Previously, Lau (one of the authors) pointed out that the deposition of an amorphous thin film by atomic layer deposition (ALD) on a substrate with nano-sized roughness probably has a surface smoothing effect. In this letter, polycrystalline zinc oxide deposited by ALD onto a smooth substrate was used as a substrate with nano-sized roughness. Atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (XTEM) were used to demonstrate that an amorphous aluminum oxide thin film deposited by ALD can reduce the surface roughness of a polycrystalline zinc oxide coated substrate.

  15. Atomic layer deposition of aluminum sulfide thin films using trimethylaluminum and hydrogen sulfide

    SciTech Connect (OSTI)

    Sinha, Soumyadeep; Sarkar, Shaibal K.; Mahuli, Neha


    Sequential exposures of trimethylaluminum and hydrogen sulfide are used to deposit aluminum sulfide thin films by atomic layer deposition (ALD) in the temperature ranging from 100 to 200?C. Growth rate of 1.3 per ALD cycle is achieved by in-situ quartz crystal microbalance measurements. It is found that the growth rate per ALD cycle is highly dependent on the purging time between the two precursors. Increased purge time results in higher growth rate. Surface limited chemistry during each ALD half cycle is studied by in-situ Fourier transformed infrared vibration spectroscopy. Time of flight secondary ion-mass spectroscopy measurement is used to confirm elemental composition of the deposited films.

  16. In situ study of HfO{sub 2} atomic layer deposition on InP(100)

    SciTech Connect (OSTI)

    Dong, H.; Brennan, B.; Kim, J.; Hinkle, C. L.; Wallace, R. M.; Zhernokletov, D.


    The interfacial chemistry of the native oxide and chemically treated InP samples during atomic layer deposition (ALD) HfO{sub 2} growth at 250 Degree-Sign C has been studied by in situ X-ray photoelectron spectroscopy. The In-oxide concentration is seen to gradually decrease on the native oxide and acid etched samples. No significant changes of the P-oxide concentrations are detected, while the P-oxides chemical states are seen to change gradually during the initial cycles of ALD on the native oxide and the chemically treated samples. (NH{sub 4}){sub 2}S treatment strongly decreases In-oxide and P-oxide concentrations prior to ALD and maintains low concentrations during the ALD process.

  17. Enhanced Dry Reforming of Methane on Ni and Ni-Pt Catalysts Synthesized by Atomic Layer Deposition

    SciTech Connect (OSTI)

    Gould, Troy D.; Montemore, Matthew M.; Lubers, Alia M.; Ellis, Lucas D.; Weimer, Alan; Falconer, John L.; Medlin, James W.


    Atomic layer deposition (ALD) was used to deposit Ni and Pt on alumina supports to form monometallic and bimetallic catalysts with initial particle sizes of 12.4 nm. The ALD catalysts were more active (per mass of metal) than catalysts prepared by incipient wetness (IW) for dry reforming of methane (DRM), and they did not form carbon whiskers during reaction due to their sufficiently small size. Catalysts modified by Pt ALD had higher rates of reaction per mass of metal and inhibited coking, whereas NiPt catalysts synthesized by IW still formed carbon whiskers. Temperature-programmed reduction of Ni catalysts modified by Pt ALD indicated the presence of bimetallic interaction. Density functional theory calculations suggested that under reaction conditions, the NiPt surfaces form Ni-terminated surfaces that are associated with higher DRM rates (due to their C and O adsorption energies, as well as the CO formation and CH4 dissociation energies).

  18. Angel Yanguas-Gil | Argonne National Laboratory

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    Angel Yanguas-Gil Angel Yanguas-Gil Principal Materials Scientist & Institute Fellow, Northwestern Argonne Institute of Science and Engineering Telephone 630-252-7353 E-mail Website Personal site Twitter Argonne ALD site


    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)


  20. Subtask 3: Nanostructured Architectures for Photovoltaic and Photochemical

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Conversion | ANSER Center | Argonne-Northwestern National Laboratory Subtask 3: Nanostructured Architectures for Photovoltaic and Photochemical Energy Conversion Home > Research > Subtask 3 The above figure depicts an ALD-Modified "Rust" Surface for enhanced electrode activity. The above figure depicts an ALD-Modified "Rust" Surface for enhanced electrode activity. The research of Subtask 3 defines, develops, models, and tests robust new nanostructured

  1. Integrating atomic layer deposition and ultra-high vacuum physical vapor deposition for in situ fabrication of tunnel junctions

    SciTech Connect (OSTI)

    Elliot, Alan J. E-mail:; Malek, Gary A.; Lu, Rongtao; Han, Siyuan; Wu, Judy Z. E-mail:; Yu, Haifeng; Zhao, Shiping


    Atomic Layer Deposition (ALD) is a promising technique for growing ultrathin, pristine dielectrics on metal substrates, which is essential to many electronic devices. Tunnel junctions are an excellent example which require a leak-free, ultrathin dielectric tunnel barrier of typical thickness around 1 nm between two metal electrodes. A challenge in the development of ultrathin dielectric tunnel barriers using ALD is controlling the nucleation of dielectrics on metals with minimal formation of native oxides at the metal surface for high-quality interfaces between the tunnel barrier and metal electrodes. This poses a critical need for integrating ALD with ultra-high vacuum (UHV) physical vapor deposition. In order to address these challenges, a viscous-flow ALD chamber was designed and interfaced to an UHV magnetron sputtering chamber via a load lock. A sample transportation system was implemented for in situ sample transfer between the ALD, load lock, and sputtering chambers. Using this integrated ALD-UHV sputtering system, superconductor-insulator-superconductor (SIS) Nb-Al/Al{sub 2}O{sub 2}/Nb Josephson tunnel junctions were fabricated with tunnel barriers of thickness varied from sub-nm to ?1 nm. The suitability of using an Al wetting layer for initiation of the ALD Al{sub 2}O{sub 3} tunnel barrier was investigated with ellipsometry, atomic force microscopy, and electrical transport measurements. With optimized processing conditions, leak-free SIS tunnel junctions were obtained, demonstrating the viability of this integrated ALD-UHV sputtering system for the fabrication of tunnel junctions and devices comprised of metal-dielectric-metal multilayers.

  2. Precise Application of Transparent Conductive Oxide Coatings for Flat Panel

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Displays and Photovoltaic Cells - Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Precise Application of Transparent Conductive Oxide Coatings for Flat Panel Displays and Photovoltaic Cells Argonne National Laboratory Contact ANL About This Technology <p align="center"> New <em>ALD reaction chamber containing 12-in x 12-in piece of plate glass</em></p> New ALD reaction

  3. Customized Nanoengineered Coatings for Science and Industry | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    National Laboratory Customized Nanoengineered Coatings for Science and Industry Nanoengineered coatings have diverse applications in the manufacture of microelectronics, optics, sensors and solid-state detectors, to name a few. Of the many techniques for producing manoengineered coatings, atomic layer deposition, or ALD, offers superlative performance. Argonne's advanced ALD materials capabilities and intellectual property are available to scientific firms and industry. PDF icon

  4. NEES - EFRC | University of Maryland Energy Frontier Research Center

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    2015 DOE EFRC Principal Investigators' Meeting NEES Participates in DOE EFRC Principal Investigators' Meeting in Washington, DC. Carbonized leaf membrane as Na+ battery anode Improving Lithium Battery Performance by Characterizing Native Processes ALD Protection of Next-Generation Metal Anodes Single Material All-Solid-State Li-ion Batteries ALD Solid Electrolytes Nonuniform Si Loss in Nanowire Anodes during Li Cycling Precision Nanobatteries by the Billions Scaling limits for miniature

  5. Local deposition of high-purity Pt nanostructures by combining electron beam induced deposition and atomic layer deposition

    SciTech Connect (OSTI)

    Mackus, A. J. M.; Sanden, M. C. M. van de; Kessels, W. M. M.; Mulders, J. J. L.


    An approach for direct-write fabrication of high-purity platinum nanostructures has been developed by combining nanoscale lateral patterning by electron beam induced deposition (EBID) with area-selective deposition of high quality material by atomic layer deposition (ALD). Because virtually pure, polycrystalline Pt nanostructures are obtained, the method extends the application possibilities of EBID, whereas compared to other area-selective ALD approaches, a much higher resolution is attainable; potentially down to sub-10 nm lateral dimensions.

  6. Controlling Atomic Layer Deposition of TiO2 in Aerogels through Surface Functionalization

    SciTech Connect (OSTI)

    Ghosal, S; Baumann, T F; King, J S; Kucheyev, S; Wang, Y; Worsley, M A; Biener, J; Bent, S F; Hamza, A V


    This report demonstrates a chemical functionalization method for controlling atomic layer deposition (ALD) of TiO{sub 2} in low-density nanoporous materials. Functionalization of silica aerogel with trimethylsilane is shown to strongly suppress TiO{sub 2} growth via ALD. Subsequent modification of the functionalization through selective removal of the hydrocarbon groups reactivates the aerogel towards TiO{sub 2} deposition. These results demonstrate the potential use of ALD as a selective tool for creating novel nanoporous materials. Nanoporous materials present significant technological advantage for a wide range of applications, including catalysis, energy storage and conversion, nanoelectronics to name just a few (1-4). Hence, there is considerable interest in developing synthetic pathways for the fabrication of nanoporous materials with tailored properties. Aerogels (AGs) are unique low-density, open-cell porous materials consisting of submicrometer pores and ligaments that can be used as a robust material platform for designing novel nanoporous materials. In recent years, a synthetic approach based on ALD on AG templates has emerged as a promising method for the directed growth of nanoporous materials (5-11, 18). This approach has been used successfully to prepare millimeter-sized high aspect ratio aerogels coated uniformly with zinc oxide (ZnO), tungsten (W) and alumina (Al{sub 2}O{sub 3}) (10, 11). The ALD process utilizes two sequential, self-limiting surface reactions resulting in a layer-by-layer growth mode. The self limiting nature of the surface reactions makes ALD a particularly suitable technique for uniform deposition onto high aspect ratio porous substrates. Additionally, chemical specificity of the surface reactions in ALD enables one to control the deposition process through selective functionalization of the substrate surface. In fact the functionalization of planar substrates such as silicon wafers with organosilane groups (R{sub n}SiX{sub 4-n} (n = 1-3)) has been shown to deactivate the substrate towards ZrO{sub 2}, HfO{sub 2}, ZnO, and TiO{sub 2} ALD processes (12-16). A possible mechanism for the deactivation effect is the blocking of surface functional groups, such as hydroxyl (OH) moieties, which serve as chemisorption sites for the ALD precursors and hence are essential for nucleating the deposition process. Henceforth, we shall refer to these surface functional groups as nucleation sites for the ALD process.

  7. Modeling precursor diffusion and reaction of atomic layer deposition in porous structures

    SciTech Connect (OSTI)

    Keuter, Thomas, E-mail:; Menzler, Norbert Heribert; Mauer, Georg; Vondahlen, Frank; Vaen, Robert; Buchkremer, Hans Peter [Forschungszentrum Jlich, Institute of Energy and Climate Research (IEK-1), 52425 Jlich (Germany)


    Atomic layer deposition (ALD) is a technique for depositing thin films of materials with a precise thickness control and uniformity using the self-limitation of the underlying reactions. Usually, it is difficult to predict the result of the ALD process for given external parameters, e.g., the precursor exposure time or the size of the precursor molecules. Therefore, a deeper insight into ALD by modeling the process is needed to improve process control and to achieve more economical coatings. In this paper, a detailed, microscopic approach based on the model developed by Yanguas-Gil and Elam is presented and additionally compared with the experiment. Precursor diffusion and second-order reaction kinetics are combined to identify the influence of the porous substrate's microstructural parameters and the influence of precursor properties on the coating. The thickness of the deposited film is calculated for different depths inside the porous structure in relation to the precursor exposure time, the precursor vapor pressure, and other parameters. Good agreement with experimental results was obtained for ALD zirconiumdioxide (ZrO{sub 2}) films using the precursors tetrakis(ethylmethylamido)zirconium and O{sub 2}. The derivation can be adjusted to describe other features of ALD processes, e.g., precursor and reactive site losses, different growth modes, pore size reduction, and surface diffusion.

  8. Enhanced photoresponse of conformal TiO{sub 2}/Ag nanorod array-based Schottky photodiodes fabricated via successive glancing angle and atomic layer deposition

    SciTech Connect (OSTI)

    Haider, Ali; Biyikli, Necmi; Cansizoglu, Hilal; Cansizoglu, Mehmet Fatih; Karabacak, Tansel; Okyay, Ali Kemal


    In this study, the authors demonstrate a proof of concept nanostructured photodiode fabrication method via successive glancing angle deposition (GLAD) and atomic layer deposition (ALD). The fabricated metal-semiconductor nanorod (NR) arrays offer enhanced photoresponse compared to conventional planar thin-film counterparts. Silver (Ag) metallic NR arrays were deposited on Ag-film/Si templates by utilizing GLAD. Subsequently, titanium dioxide (TiO{sub 2}) was deposited conformally on Ag NRs via ALD. Scanning electron microscopy studies confirmed the successful formation of vertically aligned Ag NRs deposited via GLAD and conformal deposition of TiO{sub 2} on Ag NRs via ALD. Following the growth of TiO{sub 2} on Ag NRs, aluminum metallic top contacts were formed to complete the fabrication of NR-based Schottky photodiodes. Nanostructured devices exhibited a photo response enhancement factor of 1.49??10{sup 2} under a reverse bias of 3 V.

  9. Low temperature thin film transistors with hollow cathode plasma-assisted atomic layer deposition based GaN channels

    SciTech Connect (OSTI)

    Bolat, S. E-mail:; Tekcan, B.; Ozgit-Akgun, C.; Biyikli, N.; Okyay, A. K. E-mail:


    We report GaN thin film transistors (TFT) with a thermal budget below 250?C. GaN thin films are grown at 200?C by hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD). HCPA-ALD-based GaN thin films are found to have a polycrystalline wurtzite structure with an average crystallite size of 9.3?nm. TFTs with bottom gate configuration are fabricated with HCPA-ALD grown GaN channel layers. Fabricated TFTs exhibit n-type field effect characteristics. N-channel GaN TFTs demonstrated on-to-off ratios (I{sub ON}/I{sub OFF}) of 10{sup 3} and sub-threshold swing of 3.3?V/decade. The entire TFT device fabrication process temperature is below 250?C, which is the lowest process temperature reported for GaN based transistors, so far.

  10. Property transformation of graphene with Al{sub 2}O{sub 3} films deposited directly by atomic layer deposition

    SciTech Connect (OSTI)

    Zheng, Li; Cao, Duo; Wang, Zhongjian; Xia, Chao [State Key Laboratory of Functional Materials for Informatics, SIMIT, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Cheng, Xinhong, E-mail:; Yu, Yuehui [State Key Laboratory of Functional Materials for Informatics, SIMIT, Chinese Academy of Sciences, Shanghai 200050 (China); Shen, Dashen [University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)


    Al{sub 2}O{sub 3} films are deposited directly onto graphene by H{sub 2}O-based atomic layer deposition (ALD), and the films are pinhole-free and continuously cover the graphene surface. The growth process of Al{sub 2}O{sub 3} films does not introduce any detective defects in graphene, suppresses the hysteresis effect and tunes the graphene doping to n-type. The self-cleaning of ALD growth process, together with the physically absorbed H{sub 2}O and oxygen-deficient ALD environment consumes OH{sup ?} bonds, suppresses the p-doping of graphene, shifts Dirac point to negative gate bias and enhances the electron mobility.

  11. Low interface defect density of atomic layer deposition BeO with self-cleaning reaction for InGaAs metal oxide semiconductor field effect transistors

    SciTech Connect (OSTI)

    Shin, H. S. [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of) [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of); SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); The University of Texas, Austin, Texas 78758 (United States); Yum, J. H. [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States) [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); The University of Texas, Austin, Texas 78758 (United States); Johnson, D. W. [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States) [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); Texas A and M University College Station, Texas 77843 (United States); Harris, H. R. [Texas A and M University College Station, Texas 77843 (United States)] [Texas A and M University College Station, Texas 77843 (United States); Hudnall, Todd W. [Texas State University, 601 University Drive, San Marcos, Texas 78666 (United States)] [Texas State University, 601 University Drive, San Marcos, Texas 78666 (United States); Oh, J. [Yonsei University, Incheon, 406-840 (Korea, Republic of)] [Yonsei University, Incheon, 406-840 (Korea, Republic of); Kirsch, P.; Wang, W.-E. [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States)] [SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 (United States); Bielawski, C. W.; Banerjee, S. K.; Lee, J. C. [The University of Texas, Austin, Texas 78758 (United States)] [The University of Texas, Austin, Texas 78758 (United States); Lee, H. D. [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)] [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)


    In this paper, we discuss atomic configuration of atomic layer deposition (ALD) beryllium oxide (BeO) using the quantum chemistry to understand the theoretical origin. BeO has shorter bond length, higher reaction enthalpy, and larger bandgap energy compared with those of ALD aluminum oxide. It is shown that the excellent material properties of ALD BeO can reduce interface defect density due to the self-cleaning reaction and this contributes to the improvement of device performance of InGaAs MOSFETs. The low interface defect density and low leakage current of InGaAs MOSFET were demonstrated using X-ray photoelectron spectroscopy and the corresponding electrical results.

  12. Surface modification of nitrogen-doped carbon nanotubes by ozone via atomic layer deposition

    SciTech Connect (OSTI)

    Lushington, Andrew; Liu, Jian; Tang, Yongji; Li, Ruying; Sun, Xueliang, E-mail: [Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario N6A 5B9 (Canada)


    The use of ozone as an oxidizing agent for atomic layer deposition (ALD) processes is rapidly growing due to its strong oxidizing capabilities. However, the effect of ozone on nanostructured substrates such as nitrogen-doped multiwalled carbon nanotubes (NCNTs) and pristine multiwalled carbon nanotubes (PCNTs) are not very well understood and may provide an avenue toward functionalizing the carbon nanotube surface prior to deposition. The effects of ALD ozone treatment on NCNTs and PCNTs using 10?wt. % ozone at temperatures of 150, 250, and 300?C are studied. The effect of ozone pulse time and ALD cycle number on NCNTs and PCNTs was also investigated. Morphological changes to the substrate were observed by scanning electron microscopy and high resolution transmission electron microscopy. Brunauer-Emmett-Teller measurements were also conducted to determine surface area, pore size, and pore size distribution following ozone treatment. The graphitic nature of both NCNTs and PCNTs was determined using Raman analysis while x-ray photoelectron spectroscopy (XPS) was employed to probe the chemical nature of NCNTs. It was found that O{sub 3} attack occurs preferentially to the outermost geometric surface of NCNTs. Our research also revealed that the deleterious effects of ozone are found only on NCNTs while little or no damage occurs on PCNTs. Furthermore, XPS analysis indicated that ALD ozone treatment on NCNTs, at elevated temperatures, results in loss of nitrogen content. Our studies demonstrate that ALD ozone treatment is an effective avenue toward creating low nitrogen content, defect rich substrates for use in electrochemical applications and ALD of various metal/metal oxides.

  13. Numerical modeling of carrier gas flow in atomic layer deposition vacuum reactor: A comparative study of lattice Boltzmann models

    SciTech Connect (OSTI)

    Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)


    This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice BhatnagarGrossKrook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.

  14. Impact of N{sub 2} and forming gas plasma exposure on the growth and interfacial characteristics of Al{sub 2}O{sub 3} on AlGaN

    SciTech Connect (OSTI)

    Qin, Xiaoye; Dong, Hong; Brennan, Barry; Azacatl, Angelica; Kim, Jiyoung; Wallace, Robert M.


    The interface and atomic layer deposition (ALD) of Al{sub 2}O{sub 3} on the annealed, N{sub 2} plasma and forming gas (N{sub 2}:H{sub 2}) exposed Al{sub 0.25}Ga{sub 0.75}N surface was studied using in situ X-ray photoelectron spectroscopy and low energy ion scattering spectroscopy. Exposure of the Al{sub 0.25}Ga{sub 0.75}N surface to the plasma treatments is able to remove spurious carbon, and readily facilitate uniform ALD Al{sub 2}O{sub 3} nucleation.

  15. Surface and interfacial reaction study of InAs(100)-crystalline oxide interface

    SciTech Connect (OSTI)

    Zhernokletov, D. M.; Laukkanen, P.; Dong, H.; Brennan, B.; Kim, J.; Galatage, R. V.; Yakimov, M.; Tokranov, V.; Oktyabrsky, S.; Wallace, R. M.; Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080


    A crystalline oxide film on InAs(100) is investigated with in situ monochromatic x-ray photoelectron spectroscopy and low energy electron diffraction before and after in situ deposition of Al{sub 2}O{sub 3} by atomic layer deposition (ALD) as well as upon air exposure. The oxidation process leads to arsenic and indium trivalent oxidation state formation. The grown epitaxial oxide-InAs interface is stable upon ALD reactor exposure; however, trimethyl aluminum decreases oxidation states resulting in an unreconstructed surface. An increase in oxide concentration is also observed upon air exposure suggesting the crystalline oxide surface is unstable.

  16. Fluorine contamination in yttrium-doped barium zirconate film deposited by atomic layer deposition

    SciTech Connect (OSTI)

    An Jihwan; Beom Kim, Young; Sun Park, Joong; Hyung Shim, Joon; Guer, Turgut M.; Prinz, Fritz B.


    The authors have investigated the change of chemical composition, crystallinity, and ionic conductivity in fluorine contaminated yttrium-doped barium zirconate (BYZ) fabricated by atomic layer deposition (ALD). It has been identified that fluorine contamination can significantly affect the conductivity of the ALD BYZ. The authors have also successfully established the relationship between process temperature and contamination and the source of fluorine contamination, which was the perfluoroelastomer O-ring used for vacuum sealing. The total removal of fluorine contamination was achieved by using all-metal sealed chamber instead of O-ring seals.

  17. Infrared and thermoelectric power generation in thin atomic layer deposited Nb-doped TiO{sub 2} films

    SciTech Connect (OSTI)

    Mann, Harkirat S.; Lang, Brian N.; Schwab, Yosyp; Scarel, Giovanna; Niemel, Janne-Petteri; Karppinen, Maarit


    Infrared radiation is used to radiatively transfer heat to a nanometric power generator (NPG) device with a thermoelectric Nb-doped TiO{sub 2} film deposited by atomic layer deposition (ALD) as the active element, onto a borosilicate glass substrate. The linear rise of the produced voltage with respect to the temperature difference between the hot and cold junctions, typical of the Seebeck effect, is missing. The discovery of the violation of the Seebeck effect in NPG devices combined with the ability of ALD to tune thermoelectric thin film properties could be exploited to increase the efficiency of these devices for energy harvesting purposes.

  18. Light-Material Interactions in Energy Conversion - Energy Frontier Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Center (LMI-EFRC) Cambridge Nanotech Atomic Layer Deposition A Cambridge Nanotech (USA) Savannah S200 atomic layer deposition (ALD) system was purchased for conformal growth of metal oxide films. ALD is the growth of films by sequential, self-limiting, surface chemical reactions and thus allows for precise thickness control. This system is capable of depositing nearly any metal oxide (e.g., TiO2, Al2O3) and is upgradable for metal sulfide deposition. This tool is housed in N. Lewis

  19. Nucleation and growth of MgO atomic layer deposition: A real-time spectroscopic ellipsometry study

    SciTech Connect (OSTI)

    Wang, Han; Fu, Kan


    The atomic layer deposition (ALD) of MgO thin films from bis(cyclopentadienyl) magnesium and H{sub 2}O was studied using in-situ real-time spectroscopic ellipsometry (SE), ex-situ x-ray photoelectron spectroscopy, and grazing-incidence x-ray diffraction. It is found that the initial growth is not linear during the first ten cycles, and magnesium silicate forms spontaneously on the SiO{sub 2}/Si substrates at 250 C. Submonolayer sensitivity of SE is demonstrated by the analysis of each half-cycle and self-limiting adsorption, revealing characteristic features of hetero- and homo-MgO ALD processes.

  20. Bottom-gate coplanar graphene transistors with enhanced graphene adhesion on atomic layer deposition Al{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Park, Dong-Wook; Mikael, Solomon; Chang, Tzu-Hsuan; Ma, Zhenqiang; Gong, Shaoqin


    A graphene transistor with a bottom-gate coplanar structure and an atomic layer deposition (ALD) aluminum oxide (Al{sub 2}O{sub 3}) gate dielectric is demonstrated. Wetting properties of ALD Al{sub 2}O{sub 3} under different deposition conditions are investigated by measuring the surface contact angle. It is observed that the relatively hydrophobic surface is suitable for adhesion between graphene and ALD Al{sub 2}O{sub 3}. To achieve hydrophobic surface of ALD Al{sub 2}O{sub 3}, a methyl group (CH{sub 3})-terminated deposition method has been developed and compared with a hydroxyl group (OH)-terminated deposition. Based on this approach, bottom-gate coplanar graphene field-effect transistors are fabricated and characterized. A post-thermal annealing process improves the performance of the transistors by enhancing the contacts between the source/drain metal and graphene. The fabricated transistor shows an I{sub on}/I{sub off} ratio, maximum transconductance, and field-effect mobility of 4.04, 20.1??S at V{sub D}?=?0.1?V, and 249.5?cm{sup 2}/Vs, respectively.

  1. In situ study of the role of substrate temperature during atomic layer deposition of HfO{sub 2} on InP

    SciTech Connect (OSTI)

    Dong, H.; Santosh, K.C.; Qin, X.; Brennan, B.; McDonnell, S.; Kim, J.; Zhernokletov, D.; Hinkle, C. L.; Cho, K.; Wallace, R. M.; Department of Physics, University of Texas at Dallas, Richardson, Texas 75080


    The dependence of the “self cleaning” effect of the substrate oxides on substrate temperature during atomic layer deposition (ALD) of HfO{sub 2} on various chemically treated and native oxide InP (100) substrates is investigated using in situ X-ray photoelectron spectroscopy. The removal of In-oxide is found to be more efficient at higher ALD temperatures. The P oxidation states on native oxide and acid etched samples are seen to change, with the total P-oxide concentration remaining constant, after 10 cycles of ALD HfO{sub 2} at different temperatures. An (NH{sub 4}){sub 2} S treatment is seen to effectively remove native oxides and passivate the InP surfaces independent of substrate temperature studied (200 °C, 250 °C and 300 °C) before and after the ALD process. Density functional theory modeling provides insight into the mechanism of the changes in the P-oxide chemical states.

  2. Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone

    SciTech Connect (OSTI)

    Kannan Selvaraj, Sathees; Feinerman, Alan; Takoudis, Christos G.


    In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac){sub 2}], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1??0.01?nm/cycle within the wide ALD temperature window of 175300?C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure, refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnO{sub x}Si interface. The resistivity of the SnO{sub x} films was calculated to be 0.3?? cm. Results of this work demonstrate the possibility of introducing Sn(acac){sub 2} as tin precursor to deposit conducting ALD SnO{sub x} thin films on a silicon surface, with clean interface and no formation of undesired SiO{sub 2} or other interfacial reaction products, for transparent conducting oxide applications.

  3. Directory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    09-765 Technical Abstract 09-765 Technical Abstract ALD Produced B2O3, Al2O3 and TiO2 Coatings on Gd2O3 Burnable Poison Nanoparticles (Properties) 61915 10:12 AM 61915 10:12 AM...

  4. Initiation of atomic layer deposition of metal oxides on polymer substrates by water plasma pretreatment

    SciTech Connect (OSTI)

    Steven Brandt, E.; Grace, Jeremy M.


    The role of surface hydroxyl content in atomic layer deposition (ALD) of aluminum oxide (AO) on polymers is demonstrated by performing an atomic layer deposition of AO onto a variety of polymer types, before and after pretreatment in a plasma struck in water vapor. The treatment and deposition reactions are performed in situ in a high vacuum chamber that is interfaced to an x-ray photoelectron spectrometer to prevent adventitious exposure to atmospheric contaminants. X-ray photoelectron spectroscopy is used to follow the surface chemistries of the polymers, including theformation of surface hydroxyls and subsequent growth of AO by ALD. Using dimethyl aluminum isopropoxide and water as reactants, ALD is obtained for water-plasma-treated poly(styrene) (PS), poly(propylene) (PP), poly(vinyl alcohol) (PVA), and poly(ethylene naphthalate) (PEN). For PS, PP, and PEN, initial growth rates of AO on the native (untreated) polymers are at least an order of magnitude lower than on the same polymer surface following the plasma treatment. By contrast, native PVA is shown to initiate ALD of AO as a result of the presence of intrinsic surface hydroxyls that are derived from the repeat unit of this polymer.

  5. Biotechnology at the Cutting Edge - Keasling

    ScienceCinema (OSTI)

    Keasling, Jay


    Jay Keasling, Berkeley Lab ALD for Biosciences and CEO of the Joint BioEnergy Institute, appears in a video on biotechnology at the Smithsonian's National Museum of American History. The video is part of en exhibit titled "Science in American Life," which examines the relationship between science, technology, progress and culture through artifacts, historical photographs and multimedia technology.

  6. Carbon Nanosheets and Nanostructured Electrodes in Organic Photovoltaic Devices: Cooperative Research and Development Final Report, CRADA Number CRD-08-321

    SciTech Connect (OSTI)

    Olson, D.


    Carbon nanosheet thin films were employed as nanostructured electrodes in organic solar cells. Due to the nanostructured texture of the carbon nanosheet electrodes, there was an increase in performance over standard ITO electrodes with very thick active layers. ZnO deposited via atomic layer deposition (ALD) was used as a hole blocking layer to provide for carrier selectivity of the carbon nanosheets.

  7. Coating Strategies to Improve Lithium-ion Battery Safety

    SciTech Connect (OSTI)

    Travis, Jonathan; Orendorff, Christopher J.


    This work investigated the effects of Al2O3 ALD coatings on the performance and thermal abuse tolerance of graphite based anodes and Li(NixMnyCoz)O2 (NMC) based cathodes. It was found that 5 cycles of Al2O3 ALD on the graphite anode increased the onset temperature of thermal runaway by approximately 20 C and drastically reduced the anodes contribution to the overall amount of heat released during thermal runaway. Although Al2O3 ALD improves the cycling stability of NMC based cathodes, the thermal abuse tolerance was not greatly improved. A series of conductive aluminum oxide/carbon composites were created and characterized as potential thicker protective coatings for use on NMC based cathode materials. A series of electrodes were coated with manganese monoxide ALD to test the efficacy of an oxygen scavenging coating on NMC based cathodes.

  8. Microscopic silicon-based lateral high-aspect-ratio structures for thin film conformality analysis

    SciTech Connect (OSTI)

    Gao, Feng; Arpiainen, Sanna; Puurunen, Riikka L.


    Film conformality is one of the major drivers for the interest in atomic layer deposition (ALD) processes. This work presents new silicon-based microscopic lateral high-aspect-ratio (LHAR) test structures for the analysis of the conformality of thin films deposited by ALD and by other chemical vapor deposition means. The microscopic LHAR structures consist of a lateral cavity inside silicon with a roof supported by pillars. The cavity length (e.g., 205000??m) and cavity height (e.g., 2001000?nm) can be varied, giving aspect ratios of, e.g., 20:1 to 25?000:1. Film conformality can be analyzed with the microscopic LHAR by several means, as demonstrated for the ALD Al{sub 2}O{sub 3} and TiO{sub 2} processes from Me{sub 3}Al/H{sub 2}O and TiCl{sub 4}/H{sub 2}O. The microscopic LHAR test structures introduced in this work expose a new parameter space for thin film conformality investigations expected to prove useful in the development, tuning and modeling of ALD and other chemical vapor deposition processes.

  9. Initial growth, refractive index, and crystallinity of thermal and plasma-enhanced atomic layer deposition AlN films

    SciTech Connect (OSTI)

    Van Bui, Hao Wiggers, Frank B.; Gupta, Anubha; Nguyen, Minh D.; Aarnink, Antonius A. I.; Jong, Michel P. de; Kovalgin, Alexey Y.


    The authors have studied and compared the initial growth and properties of AlN films deposited on Si(111) by thermal and plasma-enhanced atomic layer deposition (ALD) using trimethylaluminum and either ammonia or a N{sub 2}-H{sub 2} mixture as precursors. In-situ spectroscopic ellipsometry was employed to monitor the growth and measure the refractive index of the films during the deposition. The authors found that an incubation stage only occurred for thermal ALD. The linear growth for plasma-enhanced ALD (PEALD) started instantly from the beginning due to the higher nuclei density provided by the presence of plasma. The authors observed the evolution of the refractive index of AlN during the growth, which showed a rapid increase up to a thickness of about 30?nm followed by a saturation. Below this thickness, higher refractive index values were obtained for AlN films grown by PEALD, whereas above that the refractive index was slightly higher for thermal ALD films. X-ray diffraction characterization showed a wurtzite crystalline structure with a (101{sup }0) preferential orientation obtained for all the layers with a slightly better crystallinity for films grown by PEALD.

  10. Flexible Ultra Moisture Barrier Film for Thin-Film Photovoltaic Applications

    SciTech Connect (OSTI)

    David M. Dean


    Flexible Thin-film photovoltaic (TFPV) is a low cost alternative to incumbent c-Si PV products as it requires less volume of costly semiconductor materials and it can potentially reduce installation cost. Among the TFPV options, copper indium gallium diselenide (CIGS) has the highest efficiency and is believed to be one of the most attractive candidates to achieve PV cost reduction. However, CIGS cells are very moisture sensitive and require module water vapor transmission rate (WVTR) of less than 1x10-4 gram of water per square meter per day (g-H2O/m2/day). Successful development and commercialization of flexible transparent ultra moisture barrier film is the key to enable flexible CIGS TFPV products, and thus enable ultimate PV cost reduction. At DuPont, we have demonstrated at lab scale that we can successfully make polymer-based flexible transparent ultra moisture barrier film by depositing alumina on polymer films using atomic layer deposition (ALD) technology. The layer by layer ALD approach results in uniform and amorphous structure which effectively reduces pinhole density of the inorganic coating on the polymer, and thus allow the fabrication of flexible barrier film with WVTR of 10-5 g-H2O/m2/day. Currently ALD is a time-consuming process suitable only for high-value, relatively small substrates. To successfully commercialize the ALD-on-plastic technology for the PV industry, there is the need to scale up this technology and improve throughput. The goal of this contract work was to build a prototype demonstrating that the ALD technology could be scaled-up for commercial use. Unfortunately, the prototype failed to produce an ultra-barrier film by the close of the project.

  11. Energy Technology Division research summary - 1999.

    SciTech Connect (OSTI)


    The Energy Technology Division provides materials and engineering technology support to a wide range of programs important to the US Department of Energy. As shown on the preceding page, the Division is organized into ten sections, five with concentrations in the materials area and five in engineering technology. Materials expertise includes fabrication, mechanical properties, corrosion, friction and lubrication, and irradiation effects. Our major engineering strengths are in heat and mass flow, sensors and instrumentation, nondestructive testing, transportation, and electromechanics and superconductivity applications. The Division Safety Coordinator, Environmental Compliance Officers, Quality Assurance Representative, Financial Administrator, and Communication Coordinator report directly to the Division Director. The Division Director is personally responsible for cultural diversity and is a member of the Laboratory-wide Cultural Diversity Advisory Committee. The Division's capabilities are generally applied to issues associated with energy production, transportation, utilization, or conservation, or with environmental issues linked to energy. As shown in the organization chart on the next page, the Division reports administratively to the Associate Laboratory Director (ALD) for Energy and Environmental Science and Technology (EEST) through the General Manager for Environmental and Industrial Technologies. While most of our programs are under the purview of the EEST ALD, we also have had programs funded under every one of the ALDs. Some of our research in superconductivity is funded through the Physical Research Program ALD. We also continue to work on a number of nuclear-energy-related programs under the ALD for Engineering Research. Detailed descriptions of our programs on a section-by-section basis are provided in the remainder of this book.

  12. Waterless TiO{sub 2} atomic layer deposition using titanium tetrachloride and titanium tetraisopropoxide

    SciTech Connect (OSTI)

    Anderson, Virginia R.; Cavanagh, Andrew S.; Abdulagatov, Aziz I.; Gibbs, Zachary M.; George, Steven M.


    The surface chemistry for TiO{sub 2} atomic layer deposition (ALD) typically utilizes water or other oxidants that can oxidize underlying substrates such as magnetic disks or semiconductors. To avoid this oxidation, waterless or oxidant-free surface chemistry can be used that involves titanium halides and titanium alkoxides. In this study, waterless TiO{sub 2} ALD was accomplished using titanium tetrachloride (TiCl{sub 4}) and titanium tetraisopropoxide (TTIP). In situ transmission Fourier transform infrared (FTIR) studies were employed to study the surface species and the reactions during waterless TiO{sub 2} ALD. At low temperatures between 125 and 225??C, the FTIR absorbance spectra revealed that the isopropoxide species remained on the surface after TTIP exposures. The TiCl{sub 4} exposures then removed the isopropoxide species and deposited additional titanium species. At high temperatures between 250 and 300??C, the isopropoxide species were converted to hydroxyl species by ?-hydride elimination. The observation of propene gaseous reaction product by quadrupole mass spectrometry (QMS) confirmed the ?-hydride elimination reaction pathway. The TiCl{sub 4} exposures then easily reacted with the hydroxyl species. QMS studies also observed the 2-chloropropane and HCl gaseous reaction products and monitored the self-limiting nature of the TTIP reaction. Additional studies examined the waterless TiO{sub 2} ALD growth at low and high temperature. Quartz crystal microbalance measurements observed growth rates of ?3?ng/cm{sup 2} at a low temperature of 150??C. Much higher growth rates of ?15?ng/cm{sup 2} were measured at a higher temperature of 250??C under similar reaction conditions. X-ray reflectivity analysis measured a growth rate of 0.55 0.05?/cycle at 250??C. X-ray photoelectron depth-profile studies showed that the TiO{sub 2} films contained low Cl concentrations <1 at. %. This waterless TiO{sub 2} ALD process using TiCl{sub 4} and TTIP should be valuable to prevent substrate oxidation during TiO{sub 2} ALD on oxygen-sensitive substrates.

  13. Isotope analysis of diamond-surface passivation effect of high-temperature H{sub 2}O-grown atomic layer deposition-Al{sub 2}O{sub 3} films

    SciTech Connect (OSTI)

    Hiraiwa, Atsushi E-mail:; Saito, Tatsuya; Matsumura, Daisuke; Kawarada, Hiroshi


    The Al{sub 2}O{sub 3} film formed using an atomic layer deposition (ALD) method with trimethylaluminum as Al precursor and H{sub 2}O as oxidant at a high temperature (450?C) effectively passivates the p-type surface conduction (SC) layer specific to a hydrogen-terminated diamond surface, leading to a successful operation of diamond SC field-effect transistors at 400?C. In order to investigate this excellent passivation effect, we carried out an isotope analysis using D{sub 2}O instead of H{sub 2}O in the ALD and found that the Al{sub 2}O{sub 3} film formed at a conventional temperature (100?C) incorporates 50 times more CH{sub 3} groups than the high-temperature film. This CH{sub 3} is supposed to dissociate from the film when heated afterwards at a higher temperature (550?C) and causes peeling patterns on the H-terminated surface. The high-temperature film is free from this problem and has the largest mass density and dielectric constant among those investigated in this study. The isotope analysis also unveiled a relatively active H-exchange reaction between the diamond H-termination and H{sub 2}O oxidant during the high-temperature ALD, the SC still being kept intact. This dynamic and yet steady H termination is realized by the suppressed oxidation due to the endothermic reaction with H{sub 2}O. Additionally, we not only observed the kinetic isotope effect in the form of reduced growth rate of D{sub 2}O-oxidant ALD but found that the mass density and dielectric constant of D{sub 2}O-grown Al{sub 2}O{sub 3} films are smaller than those of H{sub 2}O-grown films. This is a new type of isotope effect, which is not caused by the presence of isotopes in the films unlike the traditional isotope effects that originate from the presence of isotopes itself. Hence, the high-temperature ALD is very effective in forming Al{sub 2}O{sub 3} films as a passivation and/or gate-insulation layer of high-temperature-operation diamond SC devices, and the knowledge of the aforementioned new isotope effect will be a basis for further enhancing ALD technologies in general.

  14. Ultra-thin microporous/hybrid materials

    DOE Patents [OSTI]

    Jiang, Ying-Bing; Cecchi, Joseph L.; Brinker, C. Jeffrey


    Ultra-thin hybrid and/or microporous materials and methods for their fabrication are provided. In one embodiment, the exemplary hybrid membranes can be formed including successive surface activation and reaction steps on a porous support that is patterned or non-patterned. The surface activation can be performed using remote plasma exposure to locally activate the exterior surfaces of porous support. Organic/inorganic hybrid precursors such as organometallic silane precursors can be condensed on the locally activated exterior surfaces, whereby ALD reactions can then take place between the condensed hybrid precursors and a reactant. Various embodiments can also include an intermittent replacement of ALD precursors during the membrane formation so as to enhance the hybrid molecular network of the membranes.

  15. Investigation of arsenic and antimony capping layers, and half cycle reactions during atomic layer deposition of Al{sub 2}O{sub 3} on GaSb(100)

    SciTech Connect (OSTI)

    Zhernokletov, Dmitry M.; Dong, Hong; Brennan, Barry; Kim, Jiyoung; Wallace, Robert M.; Yakimov, Michael; Tokranov, Vadim; Oktyabrsky, Serge


    In-situ monochromatic x-ray photoelectron spectroscopy, low energy electron diffraction, ion scattering spectroscopy, and transmission electron microscopy are used to examine the GaSb(100) surfaces grown by molecular beam epitaxy after thermal desorption of a protective As or Sb layer and subsequent atomic layer deposition (ALD) of Al{sub 2}O{sub 3}. An antimony protective layer is found to be more favorable compared to an arsenic capping layer as it prevents As alloys from forming with the GaSb substrate. The evolution of oxide free GaSb/Al{sub 2}O{sub 3} interface is investigated by “half-cycle” ALD reactions of trimethyl aluminum and deionized water.

  16. Resistive switching phenomena in TiO{sub x} nanoparticle layers for memory applications

    SciTech Connect (OSTI)

    Goren, Emanuelle; Tsur, Yoed; Ungureanu, Mariana; Zazpe, Raul; Rozenberg, Marcelo; Hueso, Luis E.; Casanova, Flix; Stoliar, Pablo


    Electrical characteristics of a Co/ TiO{sub x}/Co resistive memory device, fabricated by two different methods, are reported. In addition to crystalline TiO{sub 2} layers fabricated via conventional atomic layer deposition (ALD), an alternative method has been examined, where TiO{sub x} nanoparticle layers were fabricated via sol-gel. The different devices have shown different hysteresis loops with a unique crossing point for the sol-gel devices. A simple qualitative model is introduced to describe the different current-voltage behaviours by suggesting only one active metal-oxide interface for the ALD devices and two active metal-oxide interfaces for the sol-gel devices. Furthermore, we show that the resistive switching behaviour could be easily tuned by proper interface engineering and that despite having a similar active material, different fabrication methods can lead to dissimilar resistive switching properties.

  17. Infrared study on room-temperature atomic layer deposition of HfO{sub 2} using tetrakis(ethylmethylamino)hafnium and remote plasma-excited oxidizing agents

    SciTech Connect (OSTI)

    Kanomata, Kensaku [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan and Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Ohba, Hisashi; Pungboon Pansila, P.; Ahmmad, Bashir; Kubota, Shigeru; Hirahara, Kazuhiro; Hirose, Fumihiko, E-mail: [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan)


    Room-temperature atomic layer deposition (ALD) of HfO{sub 2} was examined using tetrakis (ethylmethylamino)hafnium (TEMAH) and remote plasma-excited water and oxygen. A growth rate of 0.26?nm/cycle at room temperature was achieved, and the TEMAH adsorption and its oxidization on HfO{sub 2} were investigated by multiple internal reflection infrared absorption spectroscopy. It was observed that saturated adsorption of TEMAH occurs at exposures of ?1??10{sup 5}?L (1 L?=?1??10{sup ?6} Torr s) at room temperature, and the use of remote plasma-excited water and oxygen vapor is effective in oxidizing the TEMAH molecules on the HfO{sub 2} surface, to produce OH sites. The infrared study suggested that HfOH plays a role as an adsorption site for TEMAH. The reaction mechanism of room temperature HfO{sub 2} ALD is discussed in this paper.

  18. Multilayer moisture barrier

    DOE Patents [OSTI]

    Pankow, Joel W; Jorgensen, Gary J; Terwilliger, Kent M; Glick, Stephen H; Isomaki, Nora; Harkonen, Kari; Turkulainen, Tommy


    A moisture barrier, device or product having a moisture barrier or a method of fabricating a moisture barrier having at least a polymer layer, and interfacial layer, and a barrier layer. The polymer layer may be fabricated from any suitable polymer including, but not limited to, fluoropolymers such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or ethylene-tetrafluoroethylene (ETFE). The interfacial layer may be formed by atomic layer deposition (ALD). In embodiments featuring an ALD interfacial layer, the deposited interfacial substance may be, but is not limited to, Al.sub.2O.sub.3, AlSiO.sub.x, TiO.sub.2, and an Al.sub.2O.sub.3/TiO.sub.2 laminate. The barrier layer associated with the interfacial layer may be deposited by plasma enhanced chemical vapor deposition (PECVD). The barrier layer may be a SiO.sub.xN.sub.y film.

  19. Atomic layer deposition of zinc sulfide with Zn(TMHD){sub 2}

    SciTech Connect (OSTI)

    Short, Andrew; Jewell, Leila; Doshay, Sage; Church, Carena; Keiber, Trevor; Bridges, Frank; Carter, Sue; Alers, Glenn


    The atomic layer deposition (ALD) of ZnS films with Zn(TMHD){sub 2} and in situ generated H{sub 2}S as precursors was investigated, over a temperature range of 150-375 Degree-Sign C. ALD behavior was confirmed by investigation of growth behavior and saturation curves. The properties of the films were studied with atomic force microscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy, ultraviolet-visible-infrared spectroscopy, and extended x-ray absorption fine structure. The results demonstrate a film that can penetrate a porous matrix, with a local Zn structure of bulk ZnS, and a band gap between 3.5 and 3.6 eV. The ZnS film was used as a buffer layer in nanostructured PbS quantum dot solar cell devices.

  20. Ultra-low loading Pt nanocatalysts prepared by atomic layer deposition on carbon aerogels

    SciTech Connect (OSTI)

    King, J S; Wittstock, A; Biener, J; Kucheyev, S O; Wang, Y M; Baumann, T F; Giri, S; Hamza, A V; Baeumer, M; Bent, S F


    Using atomic layer deposition (ALD), we show that Pt nanoparticles can be deposited on the inner surfaces of carbon aerogels (CA). The resultant Pt-loaded materials exhibit high catalytic activity for the oxidation of CO even at loading levels as low as {approx}0.05 mg Pt/cm{sup 2}. We observe a conversion efficiency of nearly 100% in the temperatures range 150-250 C, and the total conversion rate seems to be only limited by the thermal stability of our CA support in ambient oxygen. Our ALD approach described here is universal in nature, and can be applied to the design of new catalytic materials for a variety of applications, including fuel cells, hydrogen storage, pollution control, green chemistry, and liquid fuel production.

  1. Displacement of Hexanol by the Hexanoic Acid Overoxidation Product in Alcohol Oxidation on a Model Supported Palladium Nanoparticle Catalyst

    SciTech Connect (OSTI)

    Buchbinder, Avram M. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Center for Catalysis and Surface Science; Inst. for Catalysis in Energy Processes; Ray, Natalie A. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Center for Catalysis and Surface Science; Lu, Junling [Argonne National Lab. (ANL), Argonne, IL (United States). Energy System Division; Van Duyne, Richard P. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Center for Catalysis and Surface Science; Inst. for Catalysis in Energy Processes; Stair, Peter C. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Center for Catalysis and Surface Science; Inst. for Catalysis in Energy Processes; Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division; Weitz, Eric [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Center for Catalysis and Surface Science; Inst. for Catalysis in Energy Processes; Geiger, Franz M. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Center for Catalysis and Surface Science; Inst. for Catalysis in Energy Processes


    This work characterizes the adsorption, structure, and binding mechanism of oxygenated organic species from cyclohexane solution at the liquid/solid interface of optically flat alumina-supported palladium nanoparticle surfaces prepared by atomic layer deposition (ALD). The surface-specific nonlinear optical vibrational spectroscopy, sum-frequency generation (SFG), was used as a probe for adsorption and interfacial molecular structure. 1-Hexanoic acid is an overoxidation product and possible catalyst poison for the aerobic heterogeneous oxidation of 1-hexanol at the liquid/solid interface of Pd/Al?O? catalysts. Single component and competitive adsorption experiments show that 1-hexanoic acid adsorbs to both ALD-prepared alumina surfaces and alumina surfaces with palladium nanoparticles, that were also prepared by ALD, more strongly than does 1-hexanol. Furthermore, 1-hexanoic acid adsorbs with conformational order on ALD-prepared alumina surfaces, but on surfaces with palladium particles the adsorbates exhibit relative disorder at low surface coverage and become more ordered, on average, at higher surface coverage. Although significant differences in binding constant were not observed between surfaces with and without palladium nanoparticles, the palladium particles play an apparent role in controlling adsorbate structures. The disordered adsorption of 1-hexanoic acid most likely occurs on the alumina support, and probably results from modification of binding sites on the alumina, adjacent to the particles. In addition to providing insight on the possibility of catalyst poisoning by the overoxidation product and characterizing changes in its structure that result in only small adsorption energy changes, this work represents a step toward using surface science techniques that bridge the complexity gap between fundamental studies and realistic catalyst models.

  2. Fabrication of AlN/BN bishell hollow nanofibers by electrospinning and atomic layer deposition

    SciTech Connect (OSTI)

    Haider, Ali; Kayaci, Fatma; Uyar, Tamer; Biyikli, Necmi; Ozgit-Akgun, Cagla; Okyay, Ali Kemal


    Aluminum nitride (AlN)/boron nitride (BN) bishell hollow nanofibers (HNFs) have been fabricated by successive atomic layer deposition (ALD) of AlN and sequential chemical vapor deposition (CVD) of BN on electrospun polymeric nanofibrous template. A four-step fabrication process was utilized: (i) fabrication of polymeric (nylon 6,6) nanofibers via electrospinning, (ii) hollow cathode plasma-assisted ALD of AlN at 100?C onto electrospun polymeric nanofibers, (iii) calcination at 500?C for 2 h in order to remove the polymeric template, and (iv) sequential CVD growth of BN at 450?C. AlN/BN HNFs have been characterized for their chemical composition, surface morphology, crystal structure, and internal nanostructure using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and selected area electron diffraction. Measurements confirmed the presence of crystalline hexagonal BN and AlN within the three dimensional (3D) network of bishell HNFs with relatively low impurity content. In contrast to the smooth surface of the inner AlN layer, outer BN coating showed a highly rough 3D morphology in the form of BN nano-needle crystallites. It is shown that the combination of electrospinning and plasma-assisted low-temperature ALD/CVD can produce highly controlled multi-layered bishell nitride ceramic hollow nanostructures. While electrospinning enables easy fabrication of nanofibrous template, self-limiting reactions of plasma-assisted ALD and sequential CVD provide control over the wall thicknesses of AlN and BN layers with sub-nanometer accuracy.

  3. Precise Application of Transparent Conductive Oxide Coatings for Flat Panel

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Displays and Photovoltaic Cells | Argonne National Laboratory Precise Application of Transparent Conductive Oxide Coatings for Flat Panel Displays and Photovoltaic Cells Technology available for licensing: New transparent conducting oxide (TCO) coatings are deposited using atomic layer deposition (ALD). Provides uniform coating of complex, 3D nanostructures such as electrodes for next-generation PV cells Improved coating precision uses less material and reduces cost PDF icon

  4. LDRD Project 52523 final report :Atomic layer deposition of highly conformal tribological coatings.

    SciTech Connect (OSTI)

    Jungk, John Michael (University of Minnesota); Dugger, Michael Thomas; George, Steve M. (University of Colorado); Prasad, Somuri V.; Grubbs, Robert K.; Moody, Neville Reid; Mayer, Thomas Michael; Scharf, Thomas W.; Goeke, Ronald S.; Gerberich, William W. (University of Minnesota)


    Friction and wear are major concerns in the performance and reliability of micromechanical (MEMS) devices. While a variety of lubricant and wear resistant coatings are known which we might consider for application to MEMS devices, the severe geometric constraints of many micromechanical systems (high aspect ratios, shadowed surfaces) make most deposition methods for friction and wear-resistance coatings impossible. In this program we have produced and evaluate highly conformal, tribological coatings, deposited by atomic layer deposition (ALD), for use on surface micromachined (SMM) and LIGA structures. ALD is a chemical vapor deposition process using sequential exposure of reagents and self-limiting surface chemistry, saturating at a maximum of one monolayer per exposure cycle. The self-limiting chemistry results in conformal coating of high aspect ratio structures, with monolayer precision. ALD of a wide variety of materials is possible, but there have been no studies of structural, mechanical, and tribological properties of these films. We have developed processes for depositing thin (<100 nm) conformal coatings of selected hard and lubricious films (Al2O3, ZnO, WS2, W, and W/Al{sub 2}O{sub 3} nanolaminates), and measured their chemical, physical, mechanical and tribological properties. A significant challenge in this program was to develop instrumentation and quantitative test procedures, which did not exist, for friction, wear, film/substrate adhesion, elastic properties, stress, etc., of extremely thin films and nanolaminates. New scanning probe and nanoindentation techniques have been employed along with detailed mechanics-based models to evaluate these properties at small loads characteristic of microsystem operation. We emphasize deposition processes and fundamental properties of ALD materials, however we have also evaluated applications and film performance for model SMM and LIGA devices.

  5. Energy Frontier Research Centers | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The above figure depicts an ALD-Modified "Rust" Surface for enhanced electrode activity. Energy Frontier Research Centers Argonne pulls together science and engineering leaders across institutional boundaries, allowing them to take a collaborative approach to specific scientific challenges. In 2009, the U.S. Department of Energy's Office of Science/Office of Basic Energy Sciences established the Energy Frontier Research Centers (EFRCs). These EFRCs are composed of small teams of

  6. Liliana Stan | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Liliana Stan Engineering Specialist Senior Experience Extensive experience on designing, synthesis, and characterization of multilayered structures of metal, complex-oxide films, and multifunctional nanocomposites using physical vapor deposition techniques (sputtering, ion beam assisted deposition (IBAD), e-beam evaporation) and atomic layer deposition (ALD). Educational background M.S. Electrical Engineering, University of New Mexico. B.S. Physics, University of Bucharest, Romania Research

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

    SciTech Connect (OSTI)

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


    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metalsemiconductormetal (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.

  8. Synthesis of Pt?Pd Core?Shell Nanostructures by Atomic Layer Deposition: Application in Propane Oxidative Dehydrogenation to Propylene

    SciTech Connect (OSTI)

    Lei, Y.; Liu, Bin; Lu, Junling; Lobo-Lapidus, Rodrigo J.; Wu, Tianpin; Feng, Hao; Xia, Xiaoxing; Mane, Anil U.; Libera, Joseph A.; Greeley, Jeffrey P.; Miller, Jeffrey T.; Elam, J. W.


    Atomic layer deposition (ALD) was employed to synthesize supported Pt?Pd bimetallic particles in the 1 to 2 nm range. The metal loading and composition of the supported Pt?Pd nanoparticles were controlled by varying the deposition temperature and by applying ALD metal oxide coatings to modify the support surface chemistry. Highresolution scanning transmission electron microscopy images showed monodispersed Pt?Pd nanoparticles on ALD Al2O3 - and TiO2 -modi?ed SiO2 gel. X-ray absorption spectroscopy revealed that the bimetallic nanoparticles have a stable Pt-core, Pd-shell nanostructure. Density functional theory calculations revealed that the most stable surface con?guration for the Pt? Pd alloys in an H2 environment has a Pt-core, Pd-shell nanostructure. In comparison to their monometallic counterparts, the small Pt?Pd bimetallic core?shell nanoparticles exhibited higher activity in propane oxidative dehydrogenation as compared to their physical mixture.

  9. Atomic layer deposition precursor step repetition and surface plasma pretreatment influence on semiconductor–insulator–semiconductor heterojunction solar cell

    SciTech Connect (OSTI)

    Talkenberg, Florian Illhardt, Stefan; Schmidl, Gabriele; Schleusener, Alexander; Sivakov, Vladimir; Radnóczi, György Zoltán; Pécz, Béla; Dikhanbayev, Kadyrjan; Mussabek, Gauhar; Gudovskikh, Alexander


    Semiconductor–insulator–semiconductor heterojunction solar cells were prepared using atomic layer deposition (ALD) technique. The silicon surface was treated with oxygen and hydrogen plasma in different orders before dielectric layer deposition. A plasma-enhanced ALD process was applied to deposit dielectric Al{sub 2}O{sub 3} on the plasma pretreated n-type Si(100) substrate. Aluminum doped zinc oxide (Al:ZnO or AZO) was deposited by thermal ALD and serves as transparent conductive oxide. Based on transmission electron microscopy studies the presence of thin silicon oxide (SiO{sub x}) layer was detected at the Si/Al{sub 2}O{sub 3} interface. The SiO{sub x} formation depends on the initial growth behavior of Al{sub 2}O{sub 3} and has significant influence on solar cell parameters. The authors demonstrate that a hydrogen plasma pretreatment and a precursor dose step repetition of a single precursor improve the initial growth behavior of Al{sub 2}O{sub 3} and avoid the SiO{sub x} generation. Furthermore, it improves the solar cell performance, which indicates a change of the Si/Al{sub 2}O{sub 3} interface states.

  10. Integration of atomic layer deposited high-k dielectrics on GaSb via hydrogen plasma exposure

    SciTech Connect (OSTI)

    Ruppalt, Laura B. Cleveland, Erin R.; Champlain, James G.; Bennett, Brian R.; Prokes, Sharka M.


    In this letter we report the efficacy of a hydrogen plasma pretreatment for integrating atomic layer deposited (ALD) high-k dielectric stacks with device-quality p-type GaSb(001) epitaxial layers. Molecular beam eptiaxy-grown GaSb surfaces were subjected to a 30 minute H{sub 2}/Ar plasma treatment and subsequently removed to air. High-k HfO{sub 2} and Al{sub 2}O{sub 3}/HfO{sub 2} bilayer insulating films were then deposited via ALD and samples were processed into standard metal-oxide-semiconductor (MOS) capacitors. The quality of the semiconductor/dielectric interface was probed by current-voltage and variable-frequency admittance measurements. Measurement results indicate that the H{sub 2}-plamsa pretreatment leads to a low density of interface states nearly independent of the deposited dielectric material, suggesting that pre-deposition H{sub 2}-plasma exposure, coupled with ALD of high-k dielectrics, may provide an effective means for achieving high-quality GaSb MOS structures for advanced Sb-based digital and analog electronics.

  11. High Gradient Accelerator Cavities Using Atomic Layer Deposition

    SciTech Connect (OSTI)

    Ives, Robert Lawrence; Parsons, Gregory; Williams, Philip; Oldham, Christopher; Mundy, Zach; Dolgashev, Valery


    In the Phase I program, Calabazas Creek Research, Inc. (CCR), in collaboration with North Carolina State University (NCSU), fabricated copper accelerator cavities and used Atomic Layer Deposition (ALD) to apply thin metal coatings of tungsten and platinum. It was hypothesized that a tungsten coating would provide a robust surface more resistant to arcing and arc damage. The platinum coating was predicted to reduce processing time by inhibiting oxides that form on copper surfaces soon after machining. Two sets of cavity parts were fabricated. One was coated with 35 nm of tungsten, and the other with approximately 10 nm of platinum. Only the platinum cavity parts could be high power tested during the Phase I program due to schedule and funding constraints. The platinum coated cavity exhibit poor performance when compared with pure copper cavities. Not only did arcing occur at lower power levels, but the processing time was actually longer. There were several issues that contributed to the poor performance. First, machining of the base copper cavity parts failed to achieve the quality and cleanliness standards specified to SLAC National Accelerator Center. Secondly, the ALD facilities were not configured to provide the high levels of cleanliness required. Finally, the nanometer coating applied was likely far too thin to provide the performance required. The coating was ablated or peeled from the surface in regions of high fields. It was concluded that the current ALD process could not provide improved performance over cavities produced at national laboratories using dedicated facilities.

  12. Atomic layer deposited lithium aluminum oxide: (In)dependency of film properties from pulsing sequence

    SciTech Connect (OSTI)

    Miikkulainen, Ville Nilsen, Ola; Fjellvg, Helmer; Li, Han; King, Sean W.; Laitinen, Mikko; Sajavaara, Timo


    Atomic layer deposition (ALD) holds markedly high potential of becoming the enabling method for achieving the three-dimensional all-solid-state thin-film lithium ion battery (LiB). One of the most crucial components in such a battery is the electrolyte that needs to hold both low electronic conductivity and at least fair lithium ion conductivity being at the same time pinhole free. To obtain these desired properties in an electrolyte film, one necessarily has to have a good control over the elemental composition of the deposited material. The present study reports on the properties of ALD lithium aluminum oxide (Li{sub x}Al{sub y}O{sub z}) thin films. In addition to LiB electrolyte applications, Li{sub x}Al{sub y}O{sub z} is also a candidate low dielectric constant (low-k) etch stop and diffusion barrier material in nanoelectronics applications. The Li{sub x}Al{sub y}O{sub z} films were deposited employing trimethylaluminum-O{sub 3} and lithium tert-butoxide-H{sub 2}O for Al{sub 2}O{sub 3} and Li{sub 2}O/LiOH, respectively. The composition was aimed to be controlled by varying the pulsing ratio of those two binary oxide ALD cycles. The films were characterized by several methods for composition, crystallinity and phase, electrical properties, hardness, porosity, and chemical environment. Regardless of the applied pulsing ratio of Al{sub 2}O{sub 3} and Li{sub 2}O/LiOH, all the studied ALD Li{sub x}Al{sub y}O{sub z} films of 200 and 400 nm in thickness were polycrystalline in the orthorhombic ?-LiAlO{sub 2} phase and also very similar to each other with respect to composition and other studied properties. The results are discussed in the context of both fundamental ALD chemistry and applicability of the films as thin-film LiB electrolytes and low-k etch stop and diffusion barriers.

  13. Energy Technology Division research summary 1997.

    SciTech Connect (OSTI)


    The Energy Technology Division provides materials and engineering technology support to a wide range of programs important to the US Department of Energy. As shown on the preceding page, the Division is organized into ten sections, five with concentrations in the materials area and five in engineering technology. Materials expertise includes fabrication, mechanical properties, corrosion, friction and lubrication, and irradiation effects. Our major engineering strengths are in heat and mass flow, sensors and instrumentation, nondestructive testing, transportation, and electromechanics and superconductivity applications. The Division Safety Coordinator, Environmental Compliance Officers, Quality Assurance Representative, Financial Administrator, and Communication Coordinator report directly to the Division Director. The Division Director is personally responsible for cultural diversity and is a member of the Laboratory-wide Cultural Diversity Advisory Committee. The Division's capabilities are generally applied to issues associated with energy production, transportation, utilization or conservation, or with environmental issues linked to energy. As shown in the organization chart on the next page, the Division reports administratively to the Associate Laboratory Director (ALD) for Energy and Environmental Science and Technology (EEST) through the General Manager for Environmental and Industrial Technologies. While most of our programs are under the purview of the EEST ALD, we also have had programs funded under every one of the ALDs. Some of our research in superconductivity is funded through the Physical Research Program ALD. We also continue to work on a number of nuclear-energy-related programs under the ALD for Engineering Research. Detailed descriptions of our programs on a section-by-section basis are provided in the remainder of this book. This Overview highlights some major trends. Research related to the operational safety of commercial light water nuclear reactors (LWRS) is funded by the US Nuclear Regulatory Commission (NRC). In addition to our ongoing work on environmentally assisted cracking and steam generator integrity, a major new multiyear program has been initiated to assess the performance of high-burnup fuel during loss-of-coolant accidents. The bulk of the NRC research work is carried out in four ET sections: Corrosion: Mechanics of Materials; Irradiation Performance: and Sensors, Instrumentation, and Nondestructive Evaluation. The Transportation of Hazardous Materials Section is the other main contributor; staff from that Section have worked closely with NRC staff to draft a new version of the NRC Standard Review Plan that will be used to provide guidance to NRC reviewers of applications for the renewal of nuclear plant licenses.

  14. Plasma-enhanced atomic layer deposition and etching of high-k gadolinium oxide

    SciTech Connect (OSTI)

    Vitale, Steven A.; Wyatt, Peter W.; Hodson, Chris J.


    Atomic layer deposition (ALD) of high-quality gadolinium oxide thin films is achieved using Gd(iPrCp){sub 3} and O{sub 2} plasma. Gd{sub 2}O{sub 3} growth is observed from 150 to 350 deg. C, though the optical properties of the film improve at higher temperature. True layer-by-layer ALD growth of Gd{sub 2}O{sub 3} occurred in a relatively narrow window of temperature and precursor dose. A saturated growth rate of 1.4 A/cycle was observed at 250 deg. C. As the temperature increases, high-quality films are deposited, but the growth mechanism appears to become CVD-like, indicating the onset of precursor decomposition. At 250 deg. C, the refractive index of the film is stable at {approx}1.80 regardless of other deposition conditions, and the measured dispersion characteristics are comparable to those of bulk Gd{sub 2}O{sub 3}. XPS data show that the O/Gd ratio is oxygen deficient at 1.3, and that it is also very hygroscopic. The plasma etching rate of the ALD Gd{sub 2}O{sub 3} film in a high-density helicon reactor is very low. Little difference is observed in etching rate between Cl{sub 2} and pure Ar plasmas, suggesting that physical sputtering dominates the etching. A threshold bias power exists below which etching does not occur; thus it may be possible to etch a metal gate material and stop easily on the Gd{sub 2}O{sub 3} gate dielectric. The Gd{sub 2}O{sub 3} film has a dielectric constant of about 16, exhibits low C-V hysteresis, and allows a 50 x reduction in gate leakage compared to SiO{sub 2}. However, the plasma enhanced atomic layer deposition (PE-ALD) process causes formation of an {approx}1.8 nm SiO{sub 2} interfacial layer, and generates a fixed charge of -1.21 x 10{sup 12} cm{sup -2}, both of which may limit use of PE-ALD Gd{sub 2}O{sub 3} as a gate dielectric.

  15. Shape-selective catalysts for Fischer-Tropsch chemistry. Final report : January 1, 2001 - December 31, 2008.

    SciTech Connect (OSTI)

    Cronauer, D. C.


    Argonne National Laboratory carried out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry-specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it was desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It was desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The original goal was to produce shape-selective catalysts that had the potential to limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' This cage would also restrict their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. Such catalysts were prepared with silica-containing fractal cages. The activity and strength was essentially the same as that of catalysts without the cages. Since there was no improvement, the program plan was modified as discussed below. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product molecular weight distribution could be controlled. In order to rapidly evaluate the catalytic membranes, the ALD coating processes were performed in an 'exploratory mode' in which ALD procedures from the literature appropriate for coating flat surfaces were applied to the high surface area membranes. Consequently, the Fe and Ru loadings in the membranes were likely to be smaller than those expected for complete monolayer coverage. In addition, there was likely to be significant variation in the Fe and Ru loading among the membranes due to difficulties in nucleating these materials on the aluminum oxide surfaces. The first series of experiments using coated membranes demonstrated that the technology needed further improvement. Specifically, observed catalytic FT activity was low. This low activity appeared to be due to: (1) low available surface area, (2) atomic deposition techniques that needed improvements, and (3) insufficient preconditioning of the catalyst surface prior to FT testing. Therefore, experimentation was expanded to the use of particulate silica supports having defined channels and reasonably high surface area. An effective FT catalyst consisting of ALD-deposited Co and Pt on a silica support has been prepared and demonstrated. This catalyst was more effective than a similar catalyst deposited upon a support of ALD-deposited Al{sub 2}O{sub 3} on silica. This result implies that the deposition of Al{sub 2}O{sub 3} to form a support is not as effective as desired. The addition of Pt as a Co-containing catalyst promoter has been demonstrated; it appears to primarily affect the catalyst pre-conditioning step. Co on Al{sub 2}O{sub 3} catalyst prepared by the Center for Applied Energy Research (CAER) is more effective than Argonne-prepared ALD-deposited Co on ALD-deposited Al{sub 2}O{sub 3} catalyst. The FT activity of ALD-coated Co catalyst on Al{sub 2}O{sub 3} is about linear with Co level from about 9 to 25%. A cooperative research effort was undertaken to test the deposition of platinum on Co FT catalysts; this Pt influences the effectiveness of catalyst conditioning and its continuing activity. In summary, the ALD Pt at a low concentration (0.1 wt %) was as effective as that of the wet chemical deposition technique of CAER (specifically incipient deposition on a Co catalyst that had been prepared and calcined before the Pt deposition.) The ALD technique appeared to be nominally better than the incipient wetness technique that involved co-deposition of

  16. Low-temperature atomic layer deposition of Al{sub 2}O{sub 3} on blown polyethylene films with plasma-treated surfaces

    SciTech Connect (OSTI)

    Beom Lee, Gyeong; Sik Son, Kyung; Won Park, Suk; Hyung Shim, Joon; Choi, Byoung-Ho


    In this study, a layer of Al{sub 2}O{sub 3} was deposited on blown polyethylene films by atomic layer deposition (ALD) at low temperatures, and the surface characteristics of these Al{sub 2}O{sub 3}-coated blown polyethylene films were analyzed. In order to examine the effects of the plasma treatment of the surfaces of the blown polyethylene films on the properties of the films, both untreated and plasma-treated film samples were prepared under various processing conditions. The surface characteristics of the samples were determined by x-ray photoelectron spectroscopy, as well as by measuring their surface contact angles. It was confirmed that the surfaces of the plasma-treated samples contained a hydroxyl group, which helped the precursor and the polyethylene substrate to bind. ALD of Al{sub 2}O{sub 3} was performed through sequential exposures to trimethylaluminum and H{sub 2}O at 60 Degree-Sign C. The surface morphologies of the Al{sub 2}O{sub 3}-coated blown polyethylene films were observed using atomic force microscopy and scanning electron microscopy/energy-dispersive x-ray spectroscopy. Further, it was confirmed that after ALD, the surface of the plasma-treated film was covered with alumina grains more uniformly than was the case for the surface of the untreated polymer film. It was also confirmed via the focused ion beam technique that the layer Al{sub 2}O{sub 3} conformed to the surface of the blown polyethylene film.

  17. Lipidomic changes in rat liver after long-term exposure to ethanol

    SciTech Connect (OSTI)

    Fernando, Harshica; Bhopale, Kamlesh K.; Kondraganti, Shakuntala; Kaphalia, Bhupendra S.; Shakeel Ansari, G.A.


    Alcoholic liver disease (ALD) is a serious health problem with significant morbidity and mortality. In this study we examined the progression of ALD along with lipidomic changes in rats fed ethanol for 2 and 3 months to understand the mechanism, and identify possible biomarkers. Male Fischer 344 rats were fed 5% ethanol or caloric equivalent of maltose-dextrin in a Lieber-DeCarli diet. Animals were killed at the end of 2 and 3 months and plasma and livers were collected. Portions of the liver were fixed for histological and immunohistological studies. Plasma and the liver lipids were extracted and analyzed by nuclear magnetic resonance (NMR) spectroscopy. A time dependent fatty infiltration was observed in the livers of ethanol-fed rats. Mild inflammation and oxidative stress were observed in some ethanol-fed rats at 3 months. The multivariate and principal component analysis of proton and phosphorus NMR spectroscopy data of extracted lipids from the plasma and livers showed segregation of ethanol-fed groups from the pair-fed controls. Significant hepatic lipids that were increased by ethanol exposure included fatty acids and triglycerides, whereas phosphatidylcholine (PC) decreased. However, both free fatty acids and PC decreased in the plasma. In liver lipids unsaturation of fatty acyl chains increased, contrary to plasma, where it decreased. Our studies confirm that over-accumulation of lipids in ethanol-induced liver steatosis accompanied by mild inflammation on long duration of ethanol exposure. Identified metabolic profile using NMR lipidomics could be further explored to establish biomarker signatures representing the etiopathogenesis, progression and/or severity of ALD. - Highlights: > Long term exposure to ethanol was studied. > A nuclear magnetic resonance (NMR) spectroscopy based lipidomic approach was used. > We examined the clustering pattern of the NMR data with principal component analysis. > NMR data were compared with histology and immunohistochemistry data. > Biochemical parameters were compared with the observed NMR lipid data.

  18. Carbon monoxide alleviates ethanol-induced oxidative damage and inflammatory stress through activating p38 MAPK pathway

    SciTech Connect (OSTI)

    Li, Yanyan; Gao, Chao; Shi, Yanru; Tang, Yuhan; Liu, Liang; Xiong, Ting; Du, Min; Xing, Mingyou; Liu, Liegang; Yao, Ping


    Stress-inducible protein heme oxygenase-1(HO-1) is well-appreciative to counteract oxidative damage and inflammatory stress involving the pathogenesis of alcoholic liver diseases (ALD). The potential role and signaling pathways of HO-1 metabolite carbon monoxide (CO), however, still remained unclear. To explore the precise mechanisms, ethanol-dosed adult male Balb/c mice (5.0 g/ or ethanol-incubated primary rat hepatocytes (100 mmol/L) were pretreated by tricarbonyldichlororuthenium (II) dimmer (CORM-2, 8 mg/kg for mice or 20 ?mol/L for hepatocytes), as well as other pharmacological reagents. Our data showed that CO released from HO-1 induction by quercetin prevented ethanol-derived oxidative injury, which was abolished by CO scavenger hemoglobin. The protection was mimicked by CORM-2 with the attenuation of GSH depletion, SOD inactivation, MDA overproduction, and the leakage of AST, ALT or LDH in serum and culture medium induced by ethanol. Moreover, CORM-2 injection or incubation stimulated p38 phosphorylation and suppressed abnormal Tnfa and IL-6, accompanying the alleviation of redox imbalance induced by ethanol and aggravated by inflammatory factors. The protective role of CORM-2 was abolished by SB203580 (p38 inhibitor) but not by PD98059 (ERK inhibitor) or SP600125 (JNK inhibitor). Thus, HO-1 released CO prevented ethanol-elicited hepatic oxidative damage and inflammatory stress through activating p38 MAPK pathway, suggesting a potential therapeutic role of gaseous signal molecule on ALD induced by naturally occurring phytochemicals. - Highlights: CO alleviated ethanol-derived liver oxidative and inflammatory stress in mice. CO eased ethanol and inflammatory factor-induced oxidative damage in hepatocytes. The p38 MAPK is a key signaling mechanism for the protective function of CO in ALD.

  19. Roll-to-roll atomic layer deposition process for flexible electronics encapsulation applications

    SciTech Connect (OSTI)

    Maydannik, Philipp S. Kriinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C.; Sderlund, Mikko; Soininen, Pekka; Johansson, Petri; Kuusipalo, Jurkka; Moro, Lorenza; Zeng, Xianghui


    At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20?nm thickness Al{sub 2}O{sub 3} diffusion barrier layers on 500?mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105?C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20?nm Al{sub 2}O{sub 3} films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38?C/90% relative humidity by coulometric isostaticisobaric method were below the detection limit of the instrument (<5??10{sup ?4}?g/m{sup 2} day) for films coated at web moving speed of 0.25?m/min. Measurements using the Ca test indicated water vapor transmission rates ?5??10{sup ?6} g/m{sup 2} day. Optical measurements on the coated web showed minimum transmission of 80% in the visible range that is the same as the original PEN substrate.

  20. Atomic and molecular layer deposition for surface modification

    SciTech Connect (OSTI)

    Vh-Nissi, Mika; Sievnen, Jenni; Salo, Erkki; Heikkil, Pirjo; Kentt, Eija; Johansson, Leena-Sisko; Koskinen, Jorma T.; Harlin, Ali


    Atomic and molecular layer deposition (ALD and MLD, respectively) techniques are based on repeated cycles of gassolid surface reactions. A partial monolayer of atoms or molecules is deposited to the surface during a single deposition cycle, enabling tailored film composition in principle down to molecular resolution on ideal surfaces. Typically ALD/MLD has been used for applications where uniform and pinhole free thin film is a necessity even on 3D surfaces. However, thin even non-uniform atomic and molecular deposited layers can also be used to tailor the surface characteristics of different non-ideal substrates. For example, print quality of inkjet printing on polymer films and penetration of water into porous nonwovens can be adjusted with low-temperature deposited metal oxide. In addition, adhesion of extrusion coated biopolymer to inorganic oxides can be improved with a hybrid layer based on lactic acid. - Graphical abstract: Print quality of a polylactide film surface modified with atomic layer deposition prior to inkjet printing (360 dpi) with an aqueous ink. Number of printed dots illustrated as a function of 0, 5, 15 and 25 deposition cycles of trimethylaluminum and water. - Highlights: ALD/MLD can be used to adjust surface characteristics of films and fiber materials. Hydrophobicity after few deposition cycles of Al{sub 2}O{sub 3} due to e.g. complex formation. Same effect on cellulosic fabrics observed with low temperature deposited TiO{sub 2}. Different film growth and oxidation potential with different precursors. Hybrid layer on inorganic layer can be used to improve adhesion of polymer melt.

  1. High-reliability passivation of hydrogen-terminated diamond surface by atomic layer deposition of Al{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Daicho, Akira Saito, Tatsuya; Kurihara, Shinichiro; Kawarada, Hiroshi; Hiraiwa, Atsushi


    Although the two-dimensional hole gas (2DHG) of a hydrogen-terminated diamond surface provides a unique p-type conducting layer for high-performance transistors, the conductivity is highly sensitive to its environment. Therefore, the surface must be passivated to preserve the 2DHG, especially at high temperature. We passivated the surface at high temperature (450?C) without the loss of C-H surface bonds by atomic layer deposition (ALD) and investigated the thermal reliability of the Al{sub 2}O{sub 3} film. As a result, C-H bonds were preserved, and the hole accumulation effect appeared after the Al{sub 2}O{sub 3} deposition by ALD with H{sub 2}O as an oxidant. The sheet resistivity and hole density were almost constant between room temperature and 500?C by the passivation with thick Al{sub 2}O{sub 3} film thicker than 38?nm deposited by ALD at 450?C. After the annealing at 550?C in air The sheet resistivity and hole density were preserved. These results indicate the possibility of high-temperature application of the C-H surface diamond device in air. In the case of lower deposition temperatures, the sheet resistivity increased after air annealing, suggesting an insufficient protection capability of these films. Given the result of sheet resistivity after annealing, the increase in the sheet resistivity of these samples was not greatly significant. However, bubble like patterns were observed in the Al{sub 2}O{sub 3} films formed from 200 to 400?C by air annealing at 550?C for 1 h. On the other hand, the patterns were no longer observed at 450?C deposition. Thus, this 450?C deposition is the sole solution to enabling power device application, which requires high reliability at high temperatures.

  2. SSRL HEADLINES February 2013

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8 - February 2013 View the Archives **Note for Outlook users: For easier reading, please click the bar at the top of this message that reads "This message was converted to plain text" and select "Display as HTML."** From Director PieroPianetta I'm writing this column as acting Associate Lab Director for SLAC's Stanford Synchrotron Radiation Lightsource Directorate, a role I stepped into in November, when then-ALD Chi-Chang Kao became director of the laboratory. As many of you

  3. Accelerated deployment of nanostructured hydrotreating catalysts. Final CRADA Report.

    SciTech Connect (OSTI)

    Libera, J.A.; Snyder, S.W.; Mane, A.; Elam, J.W.; Cronauer, D.C.; Muntean, J.A.; Wu, T.; Miller, J.T.


    Nanomanufacturing offers an opportunity to create domestic jobs and facilitate economic growth. In response to this need, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy issued a Research Call to develop nanomanufacturing capabilities at the National Laboratories. High performance catalysts represent a unique opportunity to deploy nanomanufacturing technologies. Re-refining of used lube oil offers an opportunity to create manufacturing jobs and decrease dependence on imported petroleum. Improved catalysts are required to produce a better quality product, decrease environmental impact, extend catalyst life, and improve overall economics of lube oil re-refining. Argonne National Laboratory (Argonne) in cooperation with Universal Lubricants, Inc. (ULI) and Chemical Engineering Partners (CEP) have carried out a Cooperative Research and Development Agreement (CRADA) to prepare nanostructured hydrotreating catalysts using atomic layer deposition (ALD) to exhibit superior performance for the re-refining of used lube oil. We investigated the upgrading of recycled lube oil by hydrogenation using commercial, synthetically-modified commercial catalysts, and synthesized catalysts. A down-flow (trickle bed) catalytic unit was used for the hydrogenation experiments. In addition to carrying out elemental analyses of the various feed and product fractions, characterization was undertaken using H{sup 1} and C{sup 13} NMR. Initially commercial were evaluated. Second these commercial catalysts were promoted with precious metals using atomic layer deposition (ALD). Performance improvements were observed that declined with catalyst aging. An alternate approach was undertaken to deeply upgrade ULI product oils. Using a synthesized catalyst, much lower hydrogenation temperatures were required than commercial catalysts. Other performance improvements were also observed. The resulting lube oil fractions were of high purity even at low reaction severity. The products recovered from both the ALD and other processes were water-white (even those from the low temperature, low residence time (high space velocity), low conversion runs). These results indicate that highly upgraded recycle lube oils can be produced using ALD-deposited active metal catalysts. The use of H{sup 1} and C{sup 13} NMR for the characterization of the treated lube oils has been shown to be effective.

  4. ATLAS Science and Technology Review

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    th Anniversary Celebration October 22-23, 2010 Physics Division, Argonne National Laboratory Building 203, Auditorium Friday, October 22: The Past as Prologue 8:00 - 8:30 Registration and coffee Chair: R.V.F. Janssens 8:30 - 8:45 Welcome by Laboratory Director and ALD E. Isaacs/S. Streiffer 8:45 - 9:30 Summary of the History of ATLAS W.F. Henning Chair: B.B. Back 9:30 - 10:30 Reminiscences 10:30 - 10:50 Break Chair: J. Nolen 10:50 - 11:25 The Impact of ATLAS on SRF Development and Applications

  5. Methods for simultaneous control of lignin content and composition, and cellulose content in plants

    DOE Patents [OSTI]

    Chiang, Vincent Lee C.; Li, Laigeng


    The present invention relates to a method of concurrently introducing multiple genes into plants and trees is provided. The method includes simultaneous transformation of plants with multiple genes from the phenylpropanoid pathways including 4CL, CAld5H, AldOMT, SAD and CAD genes and combinations thereof to produce various lines of transgenic plants displaying altered agronomic traits. The agronomic traits of the plants are regulated by the orientation of the specific genes and the selected gene combinations, which are incorporated into the plant genome.

  6. Catalytic nanoporous membranes

    DOE Patents [OSTI]

    Pellin, Michael J; Hryn, John N; Elam, Jeffrey W


    A nanoporous catalytic membrane which displays several unique features Including pores which can go through the entire thickness of the membrane. The membrane has a higher catalytic and product selectivity than conventional catalysts. Anodic aluminum oxide (AAO) membranes serve as the catalyst substrate. This substrate is then subjected to Atomic Layer Deposition (ALD), which allows the controlled narrowing of the pores from 40 nm to 10 nm in the substrate by deposition of a preparatory material. Subsequent deposition of a catalytic layer on the inner surfaces of the pores reduces pore sizes to less than 10 nm and allows for a higher degree of reaction selectivity. The small pore sizes allow control over which molecules enter the pores, and the flow-through feature can allow for partial oxidation of reactant species as opposed to complete oxidation. A nanoporous separation membrane, produced by ALD is also provided for use in gaseous and liquid separations. The membrane has a high flow rate of material with 100% selectivity. Also provided is a method for producing a catalytic membrane having flow-through pores and discreet catalytic clusters adhering to the inside surfaces of the pores.

  7. Excellent c-Si surface passivation by low-temperature atomic layer deposited titanium oxide

    SciTech Connect (OSTI)

    Liao, Baochen; Hoex, Bram; Aberle, Armin G.; Bhatia, Charanjit S.; Chi, Dongzhi


    In this work, we demonstrate that thermal atomic layer deposited (ALD) titanium oxide (TiO{sub x}) films are able to provide a—up to now unprecedented—level of surface passivation on undiffused low-resistivity crystalline silicon (c-Si). The surface passivation provided by the ALD TiO{sub x} films is activated by a post-deposition anneal and subsequent light soaking treatment. Ultralow effective surface recombination velocities down to 2.8 cm/s and 8.3 cm/s, respectively, are achieved on n-type and p-type float-zone c-Si wafers. Detailed analysis confirms that the TiO{sub x} films are nearly stoichiometric, have no significant level of contaminants, and are of amorphous nature. The passivation is found to be stable after storage in the dark for eight months. These results demonstrate that TiO{sub x} films are also capable of providing excellent passivation of undiffused c-Si surfaces on a comparable level to thermal silicon oxide, silicon nitride, and aluminum oxide. In addition, it is well known that TiO{sub x} has an optimal refractive index of 2.4 in the visible range for glass encapsulated solar cells, as well as a low extinction coefficient. Thus, the results presented in this work could facilitate the re-emergence of TiO{sub x} in the field of high-efficiency silicon wafer solar cells.

  8. Catalytic nanoporous membranes

    DOE Patents [OSTI]

    Pellin, Michael J. (Naperville, IL); Hryn, John N. (Naperville, IL); Elam, Jeffrey W. (Elmhurst, IL)


    A nanoporous catalytic membrane which displays several unique features including pores which can go through the entire thickness of the membrane. The membrane has a higher catalytic and product selectivity than conventional catalysts. Anodic aluminum oxide (AAO) membranes serve as the catalyst substrate. This substrate is then subjected to Atomic Layer Deposition (ALD), which allows the controlled narrowing of the pores from 40 nm to 10 nm in the substrate by deposition of a preparatory material. Subsequent deposition of a catalytic layer on the inner surfaces of the pores reduces pore sizes to less than 10 nm and allows for a higher degree of reaction selectivity. The small pore sizes allow control over which molecules enter the pores, and the flow-through feature can allow for partial oxidation of reactant species as opposed to complete oxidation. A nanoporous separation membrane, produced by ALD is also provided for use in gaseous and liquid separations. The membrane has a high flow rate of material with 100% selectivity.

  9. Characterization of ZnO film grown on polycarbonate by atomic layer deposition at low temperature

    SciTech Connect (OSTI)

    Lee, Gyeong Beom; Han, Gwon Deok; Shim, Joon Hyung; Choi, Byoung-Ho


    ZnO is an attractive material for use in various technological products such as phosphors, gas sensors, and transparent conductors. Recently, aluminum-doped zinc oxide has received attention as a potential replacement for indium tin oxide, which is one of the transparent conductive oxides used in flat panel displays, organic light-emitting diodes, and organic solar cells. In this study, the characteristics of ZnO films deposited on polycarbonate (PC) substrates by atomic layer deposition (ALD) are investigated for various process temperatures. The growth mechanism of these films was investigated at low process temperatures using x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). XRD and XPS were used to determine the preferred orientation and chemical composition of the films, respectively. Furthermore, the difference of the deposition mechanisms on an amorphous organic material, i.e., PC substrate and an inorganic material such as silicon was discussed from the viewpoint of the diffusion and deposition of precursors. The structure of the films was also investigated by chemical analysis in order to determine the effect of growth temperature on the films deposited by ALD.

  10. Epitaxial c-axis oriented BaTiO{sub 3} thin films on SrTiO{sub 3}-buffered Si(001) by atomic layer deposition

    SciTech Connect (OSTI)

    Ngo, Thong Q.; McDaniel, Martin D.; Ekerdt, John G., E-mail: [Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Posadas, Agham B.; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States); Hu, Chengqing; Yu, Edward T. [Department of Electrical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Bruley, John [IBM Research Division, Yorktown Heights, New York 10593 (United States)


    Atomic layer deposition (ALD) of epitaxial c-axis oriented BaTiO{sub 3} (BTO) on Si(001) using a thin (1.6?nm) buffer layer of SrTiO{sub 3} (STO) grown by molecular beam epitaxy is reported. The ALD growth of crystalline BTO films at 225??C used barium bis(triisopropylcyclopentadienyl), titanium tetraisopropoxide, and water as co-reactants. X-ray diffraction (XRD) reveals a high degree of crystallinity and c-axis orientation of as-deposited BTO films. Crystallinity is improved after vacuum annealing at 600??C. Two-dimensional XRD confirms the tetragonal structure and orientation of 720-nm thick films. The effect of the annealing process on the BTO structure is discussed. A clean STO/Si interface is found using in-situ X-ray photoelectron spectroscopy and confirmed by cross-sectional scanning transmission electron microscopy. The capacitance-voltage characteristics of 720?nm-thick BTO films are examined and show an effective dielectric constant of ?660 for the heterostructure.

  11. High aspect ratio iridescent three-dimensional metalinsulatormetal capacitors using atomic layer deposition

    SciTech Connect (OSTI)

    Burke, Micheal, E-mail:; Blake, Alan; Djara, Vladimir; O'Connell, Dan; Povey, Ian M.; Cherkaoui, Karim; Monaghan, Scott; Scully, Jim; Murphy, Richard; Hurley, Paul K.; Pemble, Martyn E.; Quinn, Aidan J., E-mail: [Tyndall National Institute, University College Cork, Cork (Ireland)


    The authors report on the structural and electrical properties of TiN/Al{sub 2}O{sub 3}/TiN metalinsulatormetal (MIM) capacitor structures in submicron three-dimensional (3D) trench geometries with an aspect ratio of ?30. A simplified process route was employed where the three layers for the MIM stack were deposited using atomic layer deposition (ALD) in a single run at a process temperature of 250?C. The TiN top and bottom electrodes were deposited via plasma-enhanced ALD using a tetrakis(dimethylamino)titanium precursor. 3D trench devices yielded capacitance densities of 36 fF/?m{sup 2} and quality factors >65 at low frequency (200?Hz), with low leakage current densities (<3 nA/cm{sup 2} at 1 V). These devices also show strong optical iridescence which, when combined with the covert embedded capacitance, show potential for system in package (SiP) anticounterfeiting applications.

  12. Continuous production of nanostructured particles using spatial atomic layer deposition

    SciTech Connect (OSTI)

    Ommen, J. Ruud van Kooijman, Dirkjan; Niet, Mark de; Talebi, Mojgan; Goulas, Aristeidis


    In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) process based on pneumatic transport of nanoparticle agglomerates. Nanoclusters of platinum (Pt) of ?1?nm diameter are deposited onto titania (TiO{sub 2}) P25 nanoparticles resulting to a continuous production of an active photocatalyst (0.120.31?wt. % of Pt) at a rate of about 1?g min{sup ?1}. Tuning the precursor injection velocity (1040?m s{sup ?1}) enhances the contact between the precursor and the pneumatically transported support flows. Decreasing the chemisorption temperature (from 250 to 100?C) results in more uniform distribution of the Pt nanoclusters as it decreases the reaction rate as compared to the rate of diffusion into the nanoparticle agglomerates. Utilizing this photocatalyst in the oxidation reaction of Acid Blue 9 showed a factor of five increase of the photocatalytic activity compared to the native P25 nanoparticles. The use of spatial particle ALD can be further expanded to deposition of nanoclusters on porous, micron-sized particles and to the production of coreshell nanoparticles enabling the robust and scalable manufacturing of nanostructured powders for catalysis and other applications.

  13. Refractory two-dimensional hole gas on hydrogenated diamond surface

    SciTech Connect (OSTI)

    Hiraiwa, Atsushi; Daicho, Akira; Kurihara, Shinichiro; Yokoyama, Yuki; Kawarada, Hiroshi


    Use of two-dimensional hole gas (2DHG), induced on a hydrogenated diamond surface, is a solution to overcoming one of demerits of diamond, i.e., deep energy levels of impurities. This 2DHG is affected by its environment and accordingly needs a passivation film to get a stable device operation especially at high temperature. In response to this requirement, we achieved the high-reliability passivation forming an Al{sub 2}O{sub 3} film on the diamond surface using an atomic-layer-deposition (ALD) method with an H{sub 2}O oxidant at 450 Degree-Sign C. The 2DHG thus protected survived air annealing at 550 Degree-Sign C for an hour, establishing a stable high-temperature operation of 2DHG devices in air. In part, this achievement is based on high stability of C-H bonds up to 870 Degree-Sign C in vacuum and above 450 Degree-Sign C in an H{sub 2}O-containing environment as in the ALD. Chemically, this stability is supported by the fact that both the thermal decomposition of C-H bonds and reaction between C-H bonds and H{sub 2}O are endothermic processes. It makes a stark contrast to the instability of Si-H bonds, which decompose even at room temperature being exposed to atomic hydrogen. In this respect, the diamond 2DHG devices are also promising as power devices expectedly being free from many instability phenomena, such as hot carrier effect and negative-bias temperature instability, associated with Si devices. As to adsorbate, which is the other prerequisite for 2DHG, it desorbed in vacuum below 250 Degree-Sign C, and accordingly some new adsorbates should have adsorbed during the ALD at 450 Degree-Sign C. As a clue to this question, we certainly confirmed that some adsorbates, other than those at room temperature, adsorbed in air above 100 Degree-Sign C and remained at least up to 290 Degree-Sign C. The identification of these adsorbates is open for further investigation.

  14. High Rate and High Capacity Li-Ion Electrodes for Vehicular Applications

    SciTech Connect (OSTI)

    Dillon, A. C.


    Significant advances in both energy density and rate capability for Li-ion batteries are necessary for implementation in electric vehicles. We have employed two different methods to improve the rate capability of high capacity electrodes. For example, we previously demonstrated that thin film high volume expansion MoO{sub 3} nanoparticle electrodes ({approx}2 {micro}m thick) have a stable capacity of {approx}630 mAh/g, at C/2 (charge/dicharge in 2 hours). By fabricating thicker conventional electrodes, an improved reversible capacity of {approx}1000 mAh/g is achieved, but the rate capability decreases. To achieve high-rate capability, we applied a thin Al{sub 2}O{sub 3} atomic layer deposition coating to enable the high volume expansion and prevent mechanical degradation. Also, we recently reported that a thin ALD Al{sub 2}O{sub 3} coating can enable natural graphite (NG) electrodes to exhibit remarkably durable cycling at 50 C. Additionally, Al{sub 2}O{sub 3} ALD films with a thickness of 2 to 4 {angstrom} have been shown to allow LiCoO{sub 2} to exhibit 89% capacity retention after 120 charge-discharge cycles performed up to 4.5 V vs. Li/Li{sup +}. Capacity fade at this high voltage is generally caused by oxidative decomposition of the electrolyte or cobalt dissolution. We have recently fabricated full cells of NG and LiCoO{sub 2} and coated both electrodes, one or the other electrode as well as neither electrode. In creating these full cells, we observed some surprising results that lead us to obtain a greater understanding of the ALD coatings. In a different approach we have employed carbon single-wall nanotubes (SWNTs) to synthesize binder-free, high-rate capability electrodes, with 95 wt.% active materials. In one case, Fe{sub 3}O{sub 4} nanorods are employed as the active storage anode material. Recently, we have also employed this method to demonstrate improved conductivity and highly improved rate capability for a LiNi{sub 0.4}Mn{sub 0.4}Co{sub 0.2}O{sub 2} cathode material. Raman spectroscopy was employed to understand how the SWNTs function as a highly flexible conductive additive.

  15. Plasmonic materials based on ZnO films and their potential for developing broadband middle-infrared absorbers

    SciTech Connect (OSTI)

    Kesim, Yunus E. Battal, Enes; Okyay, Ali K.


    Noble metals such as gold and silver have been extensively used for plasmonic applications due to their ability to support plasmons, yet they suffer from high intrinsic losses. Alternative plasmonic materials that offer low loss and tunability are desired for a new generation of efficient and agile devices. In this paper, atomic layer deposition (ALD) grown ZnO is investigated as a candidate material for plasmonic applications. Optical constants of ZnO are investigated along with figures of merit pertaining to plasmonic waveguides. We show that ZnO can alleviate the trade-off between propagation length and mode confinement width owing to tunable dielectric properties. In order to demonstrate plasmonic resonances, we simulate a grating structure and computationally demonstrate an ultra-wide-band (415 ?m) infrared absorber.

  16. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    SciTech Connect (OSTI)

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar; Okyay, Ali K.; UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara


    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO{sub 2} layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (V{sub t}) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V V{sub t} shift, the memory with CrO{sub 2} layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO{sub 2} layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  17. Nanostructure templating using low temperature atomic layer deposition

    DOE Patents [OSTI]

    Grubbs, Robert K.; Bogart, Gregory R.; Rogers, John A.


    Methods are described for making nanostructures that are mechanically, chemically and thermally stable at desired elevated temperatures, from nanostructure templates having a stability temperature that is less than the desired elevated temperature. The methods comprise depositing by atomic layer deposition (ALD) structural layers that are stable at the desired elevated temperatures, onto a template employing a graded temperature deposition scheme. At least one structural layer is deposited at an initial temperature that is less than or equal to the stability temperature of the template, and subsequent depositions made at incrementally increased deposition temperatures until the desired elevated temperature stability is achieved. Nanostructure templates include three dimensional (3D) polymeric templates having features on the order of 100 nm fabricated by proximity field nanopatterning (PnP) methods.

  18. Epitaxial Growth of GaN-based LEDs on Simple Sacrificial Substrates

    SciTech Connect (OSTI)

    Ian Ferguson; Chris Summers


    The objective of this project is to produce alternative substrate technologies for GaN-based LEDs by developing an ALD interlayer of Al{sub 2}O{sub 3} on sacrificial substrates such as ZnO and Si. A sacrificial substrate is used for device growth that can easily be removed using a wet chemical etchant leaving only the thin GaN epi-layer. After substrate removal, the GaN LED chip can then be mounted in several different ways to a metal heat sink/reflector and light extraction techniques can then be applied to the chip and compared for performance. Success in this work will lead to high efficiency LED devices with a simple low cost fabrication method and high product yield as stated by DOE goals for its solid state lighting portfolio.

  19. New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies.

    SciTech Connect (OSTI)

    Butterworth, A.L.; Becker, N.; Gainsforth, Z.; Lanzirotti, A.; Newville, M.; Proslier, T.; Stodolna, J.; Sutton, S.; Tyliszczak, T.; Westphal, A.J.; Zasadzinski, J. (UCB)


    Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and characterizing them using multiple analytical methods, including ellipsometry, Rutherford Back Scattering at Evans Analytical, Synchrotron X-ray Fluorescence (SXRF) at Advanced Photon Source (APS) Beamline 13-ID, Synchrotron X-ray Absorption Spectroscopy (XAS) at Advanced Light Source (ALS) Beamlines 11.0.2 and and by electron microscopy techniques. Our motivation for developing much-needed cross-calibration of synchrotron techniques is borne from coordinated analyses of particles captured in the aerogel of the NASA Stardust Interstellar Dust Collector (SIDC). The Stardust Interstellar Dust Preliminary Examination (ISPE) team have characterized three sub-nanogram, {approx}1{micro}m-sized fragments considered as candidates to be the first contemporary interstellar dust ever collected, based on their chemistries and trajectories. The candidates were analyzed in small wedges of aerogel in which they were extracted from the larger collector, using high sensitivity, high spatial resolution >3 keV synchrotron x-ray fluorescence spectroscopy (SXRF) and <2 keV synchrotron x-ray transmission microscopy (STXM) during Stardust ISPE. The ISPE synchrotron techniques have complementary capabilities. Hard X-ray SXRF is sensitive to sub-fg mass of elements Z {ge} 20 (calcium) and has a spatial resolution as low as 90nm. X-ray Diffraction data were collected simultaneously with SXRF data. Soft X-ray STXM at ALS beamline 11.0.2 can detect fg-mass of most elements, including cosmochemically important oxygen, magnesium, aluminum and silicon, which are invisible to SXRF in this application. ALS beamline 11.0.2 has spatial resolution better than 25 nm. Limiting factors for Stardust STXM analyses were self-imposed limits of photon dose due to radiation damage concerns, and significant attenuation of <1500 eV X-rays by {approx}80{micro}m thick, {approx}25 mg/cm{sup 3} density silica aerogel capture medium. In practice, the ISPE team characterized the major, light elements using STXM (O, Mg, Al, Si) and the heavier minor and trace elements using SXRF. The two data sets overlapped only with minor Fe and Ni ({approx}1% mass abundance), providing few quantitative cross-checks. New improved standards for cross calibration are essential for consortium-based analyses of Stardust interstellar and cometary particles, IDPs. Indeed, they have far reaching application across the whole synchrotron-based analytical community. We have synthesized three ALD multilayers simultaneously on silicon nitride membranes and silicon and characterized them using RBS (on Si), XRF (on Si{sub 3}N{sub 4}) and STXM/XAS (holey Si{sub 3}N{sub 4}). The systems we have started to work with are Al-Zn-Fe and Y-Mg-Er. We have found these ALD multi-layers to be uniform at {micro}m- to nm scales, and have found excellent consistency between four analytical techniques so far. The ALD films can also be used as a standard for e-beam instruments, eg., TEM EELS or EDX. After some early issues with the consistency of coatings to the back-side of the membrane windows, we are confident to be able to show multi-analytical agreement to within 10%. As the precision improves, we can use the new standards to verify or improve the tabulated cross-sections.

  20. High Extraction Phosphors for Solid State Lighting

    SciTech Connect (OSTI)

    Chris Summers; Hisham Menkara; Brent Wagner


    We have developed high-index, high efficiency bulk luminescent materials and novel nano-sized phosphors for improved solid-state white LED lamps. These advances can potentially contribute to reducing the loss in luminous efficiencies due to scattering, re-absorption, and thermal quenching. The bulk and nanostructured luminescent materials investigated are index matched to GaN and have broad and size-tunable absorption bands, size and impurity tuned emission bands, size-driven elimination of scattering effects, and a separation between absorption and emission bands. These innovations were accomplished through the use of novel synthesis techniques suitable for high volume production for LED lamp applications. The program produced a full-color set of high quantum yield phosphors with high chemical stability. In the bulk phosphor study, the ZnSeS:Cu,Ag phosphor was optimized to achieve >91% efficiency using erbium (Er) and other activators as sensitizers. Detailed analysis of temperature quenching effects on a large number of ZnSeS:Cu,Ag,X and strontium- and calcium-thiogallate phosphors lead to a breakthrough in the understanding of the ??anti-quenching? behavior and a physical bandgap model was developed of this phenomena. In a follow up to this study, optimized phosphor blends for high efficiency and color performance were developed and demonstrated a 2-component phosphor system with good white chromaticity, color temperature, and high color rendering. By extending the protocols of quantum dot synthesis, ??large? nanocrystals, greater than 20 nm in diameter were synthesized and exhibited bulk-like behavior and blue light absorption. The optimization of ZnSe:Mn nanophosphors achieved ~85% QE The limitations of core-shell nanocrystal systems were addressed by investigating alternative deltadoped structures. To address the manufacturability of these systems, a one-pot manufacturing protocol was developed for ZnSe:Mn nanophosphors. To enhance the stability of these material systems, the encapsulation of ZnSeS particle phosphors and ZnSeS screens with Al{sub 2}O{sub 3} and TiO{sub 2} using ALD was shown to improve the stability by >8X and also increased the luminescence efficiency due to improved surface passivation and optical coupling. A large-volume fluidized bed ALD system was designed that can be adapted to a commercial ALD or vapor deposition system. Throughout the program, optical simulations were developed to evaluate and optimize various phosphor mixtures and device configurations. For example, to define the scattering properties of nanophosphors in an LED device or in a stand-off screen geometry. Also this work significantly promoted and assisted in the implementation of realistic phosphor material models into commercial modeling programs.

  1. Memristive behavior in a junctionless flash memory cell

    SciTech Connect (OSTI)

    Orak, Ikram; rel, Mustafa; Dana, Aykutlu; Bakan, Gokhan


    We report charge storage based memristive operation of a junctionless thin film flash memory cell when it is operated as a two terminal device by grounding the gate. Unlike memristors based on nanoionics, the presented device mode, which we refer to as the flashristor mode, potentially allows greater control over the memristive properties, allowing rational design. The mode is demonstrated using a depletion type n-channel ZnO transistor grown by atomic layer deposition (ALD), with HfO{sub 2} as the tunnel dielectric, Al{sub 2}O{sub 3} as the control dielectric, and non-stoichiometric silicon nitride as the charge storage layer. The device exhibits the pinched hysteresis of a memristor and in the unoptimized device, R{sub off}/R{sub on} ratios of about 3 are presented with low operating voltages below 5?V. A simplified model predicts R{sub off}/R{sub on} ratios can be improved significantly by adjusting the native threshold voltage of the devices. The repeatability of the resistive switching is excellent and devices exhibit 10{sup 6?}s retention time, which can, in principle, be improved by engineering the gate stack and storage layer properties. The flashristor mode can find use in analog information processing applications, such as neuromorphic computing, where well-behaving and highly repeatable memristive properties are desirable.

  2. Hydroquinone-ZnO nano-laminate deposited by molecular-atomic layer deposition

    SciTech Connect (OSTI)

    Huang, Jie; Lucero, Antonio T.; Cheng, Lanxia; Kim, Jiyoung; Hwang, Hyeon Jun; Ha, Min-Woo


    In this study, we have deposited organic-inorganic hybrid semiconducting hydroquinone (HQ)/zinc oxide (ZnO) superlattices using molecular-atomic layer deposition, which enables accurate control of film thickness, excellent uniformity, and sharp interfaces at a low deposition temperature (150 °C). Self-limiting growth of organic layers is observed for the HQ precursor on ZnO surface. Nano-laminates were prepared by varying the number of HQ to ZnO cycles in order to investigate the physical and electrical effects of different HQ to ZnO ratios. It is indicated that the addition of HQ layer results in enhanced mobility and reduced carrier concentration. The highest Hall mobility of approximately 2.3 cm{sup 2}/V·s and the lowest n-type carrier concentration of approximately 1.0 × 10{sup 18}/cm{sup 3} were achieved with the organic-inorganic superlattice deposited with a ratio of 10 ZnO cycles to 1 HQ cycle. This study offers an approach to tune the electrical transport characteristics of ALD ZnO matrix thin films using an organic dopant. Moreover, with organic embedment, this nano-laminate material may be useful for flexible electronics.

  3. Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

    SciTech Connect (OSTI)

    Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.


    We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.

  4. Cathode encapsulation of organic light emitting diodes by atomic layer deposited Al{sub 2}O{sub 3} films and Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks

    SciTech Connect (OSTI)

    Keuning, W.; Weijer, P. van de; Lifka, H.; Kessels, W. M. M.; Creatore, M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Philips Research Laboratories, High Tech Campus 4, P.O. Box WAG12, 5656 AE Eindhoven (Netherlands); Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)


    Al{sub 2}O{sub 3} thin films synthesized by plasma-enhanced atomic layer deposition (ALD) at room temperature (25 deg. C) have been tested as water vapor permeation barriers for organic light emitting diode devices. Silicon nitride films (a-SiN{sub x}:H) deposited by plasma-enhanced chemical vapor deposition served as reference and were used to develop Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks. On the basis of Ca test measurements, a very low intrinsic water vapor transmission rate of {<=} 2 x 10{sup -6} g m{sup -2} day{sup -1} and 4 x 10{sup -6} g m{sup -2} day{sup -1} (20 deg. C/50% relative humidity) were found for 20-40 nm Al{sub 2}O{sub 3} and 300 nm a-SiN{sub x}:H films, respectively. The cathode particle coverage was a factor of 4 better for the Al{sub 2}O{sub 3} films compared to the a-SiN{sub x}:H films and an average of 0.12 defects per cm{sup 2} was obtained for a stack consisting of three barrier layers (Al{sub 2}O{sub 3}/a-SiN{sub x}:H/Al{sub 2}O{sub 3}).

  5. Inert gas enhanced laser-assisted purification of platinum electron-beam-induced deposits

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stanford, Michael G.; Lewis, Brett B.; Noh, Joo Hyon; Fowlkes, Jason Davidson; Rack, Philip D.


    Electron-beam-induced deposition patterns, with composition of PtC5, were purified using a pulsed laser-induced purification reaction to erode the amorphous carbon matrix and form pure platinum deposits. Enhanced mobility of residual H2O molecules via a localized injection of inert Ar–H2 (4%) is attributed to be the reactive gas species for purification of the deposits. Surface purification of deposits was realized at laser exposure times as low as 0.1 s. The ex situ purification reaction in the deposit interior was shown to be rate-limited by reactive gas diffusion into the deposit, and deposit contraction associated with the purification process caused some lossmore » of shape retention. To circumvent the intrinsic flaws of the ex situ anneal process, in situ deposition and purification techniques were explored that resemble a direct write atomic layer deposition (ALD) process. First, we explored a laser-assisted electron-beam-induced deposition (LAEBID) process augmented with reactive gas that resulted in a 75% carbon reduction compared to standard EBID. Lastly, a sequential deposition plus purification process was also developed and resulted in deposition of pure platinum deposits with high fidelity and shape retention.« less

  6. Ferroelectricity in undoped hafnium oxide

    SciTech Connect (OSTI)

    Polakowski, Patrick; Mller, Johannes


    We report the observation of ferroelectric characteristics in undoped hafnium oxide thin films in a thickness range of 420?nm. The undoped films were fabricated using atomic layer deposition (ALD) and embedded into titanium nitride based metal-insulator-metal (MIM) capacitors for electrical evaluation. Structural as well as electrical evidence for the appearance of a ferroelectric phase in pure hafnium oxide was collected with respect to film thickness and thermal budget applied during titanium nitride electrode formation. Using grazing incidence X-Ray diffraction (GIXRD) analysis, we observed an enhanced suppression of the monoclinic phase fraction in favor of an orthorhombic, potentially, ferroelectric phase with decreasing thickness/grain size and for a titanium nitride electrode formation below crystallization temperature. The electrical presence of ferroelectricity was confirmed using polarization measurements. A remanent polarization P{sub r} of up to 10??C?cm{sup ?2} as well as a read/write endurance of 1.6??10{sup 5} cycles was measured for the pure oxide. The experimental results reported here strongly support the intrinsic nature of the ferroelectric phase in hafnium oxide and expand its applicability beyond the doped systems.

  7. Hepatic lipid profiling of deer mice fed ethanol using {sup 1}H and {sup 31}P NMR spectroscopy: A dose-dependent subchronic study

    SciTech Connect (OSTI)

    Fernando, Harshica; Bhopale, Kamlesh K.; Boor, Paul J.; Ansari, G.A. Shakeel; Kaphalia, Bhupendra S.


    Chronic alcohol abuse is a 2nd major cause of liver disease resulting in significant morbidity and mortality. Alcoholic liver disease (ALD) is characterized by a wide spectrum of pathologies starting from fat accumulation (steatosis) in early reversible stage to inflammation with or without fibrosis and cirrhosis in later irreversible stages. Previously, we reported significant steatosis in the livers of hepatic alcohol dehydrogenase (ADH)-deficient (ADH{sup ?}) vs. hepatic ADH-normal (ADH{sup +}) deer mice fed 4% ethanol daily for 2 months [Bhopale et al., 2006, Alcohol 39, 179188]. However, ADH{sup ?} deer mice fed 4% ethanol also showed a significant mortality. Therefore, a dose-dependent study was conducted to understand the mechanism and identify lipid(s) involved in the development of ethanol-induced fatty liver. ADH{sup ?} and ADH{sup +} deer mice fed 1, 2 or 3.5% ethanol daily for 2 months and fatty infiltration in the livers were evaluated by histology and by measuring dry weights of extracted lipids. Lipid metabolomic changes in extracted lipids were determined by proton ({sup 1}H) and {sup 31}phosphorus ({sup 31}P) nuclear magnetic resonance (NMR) spectroscopy. The NMR data was analyzed by hierarchical clustering (HC) and principle component analysis (PCA) for pattern recognition. Extensive vacuolization by histology and significantly increased dry weights of total lipids found only in the livers of ADH{sup ?} deer mice fed 3.5% ethanol vs. pair-fed controls suggest a dose-dependent formation of fatty liver in ADH{sup ?} deer mouse model. Analysis of NMR data of ADH{sup ?} deer mice fed 3.5% ethanol vs. pair-fed controls shows increases for total cholesterol, esterified cholesterol, fatty acid methyl esters (FAMEs), triacylglycerides and unsaturation, and decreases for free cholesterol, phospholipids and allylic and diallylic protons. Certain classes of neutral lipids (cholesterol esters, fatty acyl chain (-COCH{sub 2}-) and FAMEs) were also mildly increased in ADH{sup ?} deer mice fed 1 or 2% ethanol. Only small increases were observed for allylic and diallylic protons, FAMEs and unsaturations in ADH{sup +} deer mice fed 3.5% ethanol vs. pair-fed controls. PCA of NMR data showed increased clustering by gradual separation of ethanol-fed ADH{sup ?} deer mice groups from their respective pair-fed control groups and corresponding ethanol-fed ADH{sup +} deer mice groups. Our data indicate that dose of ethanol and hepatic ADH deficiency are two key factors involved in initiation and progression of alcoholic fatty liver disease. Further studies on characterization of individual lipid entities and associated metabolic pathways altered in our deer mouse model after different durations of ethanol feeding could be important to delineate mechanism(s) and identify potential biomarker candidate(s) of early stage ALD. -- Highlights: ? Dose-dependent ethanol-induced fatty liver was studied in deer mouse model. ? A NMR-based lipidomic approach with histology and dry lipid weights was used. ? We used principal component analysis (PCA) to analyze the NMR lipidomic data. ? Dose-dependent clustering patterns by PCA were compared among the groups.

  8. Novel Dual-Functional Membrane for Controlling Carbon Dioxide Emissions from Fossil Fuel Power Plants

    SciTech Connect (OSTI)

    C. Brinker; George Xomeritakis; C.-Y. Tsai; Ying-Bing Jiang


    CO{sub 2} captured from coal-fired power plants represents three-quarters of the total cost of an entire carbon sequestration process. Conventional amine absorption or cryogenic separation requires high capital investment and is very energy intensive. Our novel membrane process is energy efficient with great potential for economical CO{sub 2} capture. Three classes of microporous sol-gel derived silica-based membranes were developed for selective CO{sub 2} removal under simulated flue gas conditions (SFG), e.g. feed of 10% vol. CO{sub 22} in N{sub 2}, 1 atm total pressure, T = 50-60 C, RH>50%, SO2>10 ppm. A novel class of amine-functional microporous silica membranes was prepared using an amine-derivatized alkoxysilane precursor, exhibiting enhanced (>70) CO{sub 2}:N{sub 2} selectivity in the presence of H{sub 2}O vapor, but its CO{sub 2} permeance was lagging (<1 MPU). Pure siliceous membranes showed higher CO{sub 2} permeance (1.5-2 MPU) but subsequent densification occurred under prolonged SFG conditions. We incorporated NiO in the microporous network up to a loading of Ni:Si = 0.2 to retard densification and achieved CO2 permeance of 0.5 MPU and CO{sub 2}:N{sub 2} selectivity of 50 after 163 h exposure to SFG conditions. However, CO{sub 2} permeance should reach greater than 2.0 MPU in order to achieve the cost of electricity (COE) goal set by DOE. We introduced the atomic layer deposition (ALD), a molecular deposition technique that substantially reduces membrane thickness with intent to improve permeance and selectivity. The deposition technique also allows the incorporation of Ni or Ag cations by proper selection of metallorganic precursors. In addition, preliminary economic analysis provides a sensitivity study on the performance and cost of the proposed membranes for CO{sub 2} capture. Significant progress has been made toward the practical applications for CO{sub 2} capture. (1 MPU = 1.0 cm{sup 3}(STP){center_dot}cm-2{center_dot}min-1{center_dot}atm-1)

  9. Liver proteomics in progressive alcoholic steatosis

    SciTech Connect (OSTI)

    Fernando, Harshica; Wiktorowicz, John E.; Soman, Kizhake V.; Kaphalia, Bhupendra S.; Khan, M. Firoze; Shakeel Ansari, G.A.


    Fatty liver is an early stage of alcoholic and nonalcoholic liver disease (ALD and NALD) that progresses to steatohepatitis and other irreversible conditions. In this study, we identified proteins that were differentially expressed in the livers of rats fed 5% ethanol in a LieberDeCarli diet daily for 1 and 3 months by discovery proteomics (two-dimensional gel electrophoresis and mass spectrometry) and non-parametric modeling (Multivariate Adaptive Regression Splines). Hepatic fatty infiltration was significantly higher in ethanol-fed animals as compared to controls, and more pronounced at 3 months of ethanol feeding. Discovery proteomics identified changes in the expression of proteins involved in alcohol, lipid, and amino acid metabolism after ethanol feeding. At 1 and 3 months, 12 and 15 different proteins were differentially expressed. Of the identified proteins, down regulation of alcohol dehydrogenase (? 1.6) at 1 month and up regulation of aldehyde dehydrogenase (2.1) at 3 months could be a protective/adaptive mechanism against ethanol toxicity. In addition, betaine-homocysteine S-methyltransferase 2 a protein responsible for methionine metabolism and previously implicated in fatty liver development was significantly up regulated (1.4) at ethanol-induced fatty liver stage (1 month) while peroxiredoxin-1 was down regulated (? 1.5) at late fatty liver stage (3 months). Nonparametric analysis of the protein spots yielded fewer proteins and narrowed the list of possible markers and identified D-dopachrome tautomerase (? 1.7, at 3 months) as a possible marker for ethanol-induced early steatohepatitis. The observed differential regulation of proteins have potential to serve as biomarker signature for the detection of steatosis and its progression to steatohepatitis once validated in plasma/serum. -- Graphical abstract: The figure shows the Hierarchial cluster analysis of differentially expressed protein spots obtained after ethanol feeding for 1 (13) and 3 (46) months. C and E represent pair-fed control and ethanol-fed rats, respectively. Highlights: ? Proteins related to ethanol-induced steatosis and mild steatohepatitis are identified. ? ADH1C and ALDH2 involved in alcohol metabolism are differentially expressed at 1 and 3 months. ? Discovery proteomics identified a group of proteins to serve as potential biomarkers. ? Using nonparametric analysis DDT is identified as a possible marker for liver damage.

  10. Laboratory Directed Research and Development Program Activities for FY 2008.

    SciTech Connect (OSTI)

    Looney,J.P.; Fox, K.


    Brookhaven National Laboratory (BNL) is a multidisciplinary laboratory that maintains a primary mission focus the physical sciences, energy sciences, and life sciences, with additional expertise in environmental sciences, energy technologies, and national security. It is managed by Brookhaven Science Associates, LLC, (BSA) under contract with the U. S. Department of Energy (DOE). BNL's Fiscal year 2008 budget was $531.6 million. There are about 2,800 employees, and another 4,300 guest scientists and students who come each year to use the Laboratory's facilities and work with the staff. The BNL Laboratory Directed Research and Development (LDRD) Program reports its status to the U.S. Department of Energy (DOE) annually in March, as required by DOE Order 413.2B, 'Laboratory Directed Research and Development,' April 19, 2006, and the Roles, Responsibilities, and Guidelines for Laboratory Directed Research and Developlnent at the Department of Energy/National Nuclear Security Administration Laboratories dated June 13, 2006. Accordingly, this is our Annual Report in which we describe the Purpose, Approach, Technical Progress and Results, and Specific Accomplishments of all LDRD projects that received funding during Fiscal Year 2008. BNL expended $12 million during Fiscal Year 2008 in support of 69 projects. The program has two categories, the annual Open Call LDRDs and Strategic LDRDs, which combine to meet the overall objectives of the LDRD Program. Proposals are solicited annually for review and approval concurrent with the next fiscal year, October 1. For the open call for proposals, an LDRD Selection Committee, comprised of the Associate Laboratory Directors (ALDs) for the Scientific Directorates, an equal number of scientists recommended by the Brookhaven Council, plus the Assistant Laboratory Director for Policy and Strategic Planning, review the proposals submitted in response to the solicitation. The Open Can LDRD category emphasizes innovative research concepts with limited management filtering to encourage the creativity of individual researchers. The competition is open to all BNL staff in programmatic, scientific, engineering, and technical support areas. Researchers submit their project proposals to the Assistant Laboratory Director for Policy and Strategic Planning. A portion of the LDRD budget is held for the Strategic LDRD (S-LDRD) category. Projects in this category focus on innovative R&D activities that support the strategic agenda of the Laboratory. The Laboratory Director entertains requests or articulates the need for S-LDRD funds at any time. Strategic LDRD Proposals also undergo rigorous peer review; the approach to review is tailored to the size and scope of the proposal. These Projects are driven by special opportunities, including: (1) Research project(s) in support of Laboratory strategic initiatives as defined and articulated by the Director; (2) Research project(s) in support of a Laboratory strategic hire; (3) Evolution of Program Development activities into research and development activities; and (4) ALD proposal(s) to the Director to support unique research opportunities. The goals and objectives of BNL's LDRD Program can be inferred fronl the Program's stated purposes. These are to (1) encourage and support the development of new ideas and technology, (2) promote the early exploration and exploitation of creative and innovative concepts, and (3) develop new 'fundable' R&D projects and programs. The emphasis is clearly articulated by BNL to be on supporting exploratory research 'which could lead to new programs, projects, and directions' for the Laboratory. We explicitly indicate that research conducted under the LDRD Program should be highly innovative, and an element of high risk as to success is acceptable. To be one of the premier DOE National Laboratories, BNL must continuously foster groundbreaking scientific research. At Brookhaven National Laboratory one such method is through its LDRD Program. This discretionary research and development tool is critical in maintaining the scientific excellence and long-term vitality of the Laboratory. Additionally, it is a means to stimulate the scientific community and foster new science and technology ideas, which becomes a major factor in achieving and maintaining staff excellence and a means to address National needs within the overall mission of the DOE and BNL.

  11. Final Report: DE- FC36-05GO15063, Fundamental Studies of Advanced High-Capacity, Reversible Metal Hydrides

    SciTech Connect (OSTI)

    Jensen, Craig; McGrady, Sean; Severa, Godwin; Eliseo, Jennifer; Chong, Marina


    The project was component of the US DOE, Metal Hydride Center of Excellence (MHCoE). The Sandia National Laboratory led center was established to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE/FreedomCAR 2010 and 2015 system targets for hydrogen storage materials. Our approach entailed a wide variety of activities ranging from synthesis, characterization, and evaluation of new candidate hydrogen storage materials; screening of catalysts for high capacity materials requiring kinetics enhancement; development of low temperature methods for nano-confinement of hydrides and determining its effects on the kinetics and thermodynamics of hydrides; and development of novel processes for the direct re-hydrogenation of materials. These efforts have resulted in several advancements the development of hydrogen storage materials. We have greatly extended the fundamental knowledge about the highly promising hydrogen storage carrier, alane (AlH?), by carrying out the first crystal structure determinations and the first determination of the heats of dehydrogenation of ?AlH? and ?-AlD?. A low-temperature homogenous organometallic approach to incorporation of Al and Mg based hydrides into carbon aerogels has been developed that that allows high loadings without degradation of the nano-porous scaffold. Nano-confinement was found to significantly improve the dehydrogenation kinetics but not effect the enthalpy of dehydrogenation. We conceived, characterized, and synthesized a novel class of potential hydrogen storage materials, bimetallic borohydrides. These novel compounds were found to have many favorable properties including release of significant amounts of hydrogen at moderate temperatures (75-190C). However, in situ IR studies in tandem with thermal gravimetric analysis have shown that about 0.5 equivalents of diborane are released during the dehydrogenation making re-hydrogenation effectively impossible and precluding these compounds from further consideration as hydrogen storage materials. The hydrogen cycling of >11 wt % between MgB? to Mg(BH?)? was achieved but required very forcing conditions. Under moderate conditions (dehydrogenation 200C; re-hydrogenation 250C, 120 atm H2), Mg(BH?)? undergoes reversible dehydrogenation to Mg(B3H8)2. Although the 2.5 wt% cycling capacity does not meet current on-board storage targets, this result provides first example of direct hydrogen cycling of a borohydride under moderate conditions and demonstrates the plausibility of finding mild, PEM fuel cell relevant conditions for the high capacity, reversible dehydrogenation of borohydrides. A method was developed for the room temperature, direct hydrogenation of Ti-doped LiH/Al in liquefied dimethyl ether under 100 atm of H?. The process has been optimized such that Ti-doped LiAlH? is obtained in >95% yield. The WTT energy efficiency our direct synthesis process has been estimated to approach the 60% U.S. DOE target. Thus our simplification of the hydrogenation half-cycle may provide the key to harnessing the long-recognized potential of this lightweight, high capacity material as a practical hydrogen carrier. Finally, we have gained insight into the fundamental basis of the enhanced hydrogen cycling kinetics of Ti-doped NaAlH? through studies by solid state H NMR, anelastic spectroscopy; muon spin rotation; and positron annihilation.

  12. Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004.

    SciTech Connect (OSTI)

    Cronauer, D.; Chemical Engineering


    Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry--specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It is desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The goal is to produce shape-selective catalysts that have the potential to limit the formation of longchain products and yet retain the active metal sites in a protected 'cage'. This cage also restricts their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. This activity report centers upon this first stage of experimentation with particulate FT catalysts. (For reference, a second experimental stage is under way to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes.) To date, experimentation has centered upon the evaluation of a sample of iron-based, spray-dried catalyst prepared by B.H. Davis of the Center of Applied Energy Research (CAER) and samples of his catalyst onto which inorganic 'shells' were deposited. The reference CAER catalyst contained a high level of dispersed fine particles, a portion of which was removed by differential settling. Reaction conditions have been established using a FT laboratory unit such that reasonable levels of CO conversion can be achieved, where therefore a valid catalyst comparison can be made. A wide range of catalytic activities was observed with SiO{sub 2}-coated FT catalysts. Two techniques were used for SiO{sub 2}coating. The first involved a caustic precipitation of SiO{sub 2} from an organo-silicate onto the CAER catalyst. The second was the acidic precipitation of an organo-silicate with aging to form fractal particles that were then deposited onto the CAER catalyst. Several resulting FT catalysts were as active as the coarse catalyst on which they were prepared. The most active ones were those with the least amount of coating, namely about 2.2 wt% SiO{sub 2}. In the case of the latter acid technique, the use of HCl and HNO{sub 3} was much more effective than that of H{sub 2}SO{sub 4}. Scanning electron microscopy (SEM) was used to observe and analyze as-received and treated FT catalysts. It was observed that (1) spherical particles of CAER FT catalyst were made up of agglomerates of particles that were, in turn, also agglomerates; (2) the spray drying process of CAER apparently concentrated the Si precursor at the surface during drying; (3) while SEM pointed out broad differences in the appearance of the prepared catalyst particles, there was little indication that the catalysts were being uniformly coated with a cage-like protective surface, with perhaps the exception of HNO{sub 3}-precipitated catalyst; and (4) there was only a limited penetration of carbon (i.e., CO) into the FT catalyst during the conditioning and FT reaction steps.