Sample records for vapor deposition growth

  1. DIAMOND CHEMICAL VAPOR DEPOSITION Nucleation and Early Growth Stages

    E-Print Network [OSTI]

    Dandy, David

    a reality. Epi- taxial diamond has been grown on diamond and cubic-BN. Polycrystalline diamond films haveDIAMOND CHEMICAL VAPOR DEPOSITION Nucleation and Early Growth Stages by Huimin Liu David S. Dandy of high-quality diamond coatings on preshaped parts and synthesis of free-standing shapes of diamond

  2. Real-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic sensing

    E-Print Network [OSTI]

    Rubloff, Gary W.

    to a production-scale tungsten chemical vapor deposition cluster tool for in situ process sensing. Process gasesReal-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic to achieve run-to-run process control of the deposited tungsten film thickness. © 2001 American Vacuum

  3. Growth of graphene underlayers by chemical vapor deposition

    SciTech Connect (OSTI)

    Fabiane, Mopeli; Khamlich, Saleh; Bello, Abdulhakeem; Dangbegnon, Julien; Momodu, Damilola; Manyala, Ncholu, E-mail: ncholu.manyala@up.ac.za [Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa)] [Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa); Charlie Johnson, A. T. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)] [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2013-11-15T23:59:59.000Z

    We present a simple and very convincing approach to visualizing that subsequent layers of graphene grow between the existing monolayer graphene and the copper catalyst in chemical vapor deposition (CVD). Graphene samples were grown by CVD and then transferred onto glass substrates by the bubbling method in two ways, either direct-transfer (DT) to yield poly (methyl methacrylate) (PMMA)/graphene/glass or (2) inverted transfer (IT) to yield graphene/PMMA/glass. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to reveal surface features for both the DT and IT samples. The results from FE-SEM and AFM topographic analyses of the surfaces revealed the underlayer growth of subsequent layers. The subsequent layers in the IT samples are visualized as 3D structures, where the smaller graphene layers lie above the larger layers stacked in a concentric manner. The results support the formation of the so-called “inverted wedding cake” stacking in multilayer graphene growth.

  4. Bilayer graphene growth by low pressure chemical vapor deposition on copper foil

    E-Print Network [OSTI]

    Fang, Wenjing, S.M. Massachusetts Institute of Technology

    2012-01-01T23:59:59.000Z

    Successfully integrating graphene in standard processes for applications in electronics relies on the synthesis of high-quality films. In this work we study Low Pressure Chemical Vapor Deposition (LPCVD) growth of bilayer ...

  5. Self-Limiting Chemical Vapor Deposition Growth of Monolayer Graphene from Ethanol

    E-Print Network [OSTI]

    Maruyama, Shigeo

    1 Self-Limiting Chemical Vapor Deposition Growth of Monolayer Graphene from Ethanol Pei Zhao, and systematically investigate the growth of graphene from ethanol and compare its self-limiting behavior over copper facets with different identities. Results show that the growth of graphene from ethanol in the LPCVD

  6. Diamond growth on WC-Co substrates by hot filament chemical vapor deposition: Effect of filamentsubstrate separation

    E-Print Network [OSTI]

    Bristol, University of

    Polycrystalline diamond films have been grown by hot filament (HF) chemical vapor deposition on WC-Co bar is an established technique for growing hard, wear- resistant polycrystalline diamond films on a range of substratesDiamond growth on WC-Co substrates by hot filament chemical vapor deposition: Effect of filament

  7. Continuous growth of single-wall carbon nanotubes using chemical vapor deposition

    DOE Patents [OSTI]

    Grigorian, Leonid (Raymond, OH); Hornyak, Louis (Evergreen, CO); Dillon, Anne C (Boulder, CO); Heben, Michael J (Denver, CO)

    2008-10-07T23:59:59.000Z

    The invention relates to a chemical vapor deposition process for the continuous growth of a carbon single-wall nanotube where a carbon-containing gas composition is contacted with a porous membrane and decomposed in the presence of a catalyst to grow single-wall carbon nanotube material. A pressure differential exists across the porous membrane such that the pressure on one side of the membrane is less than that on the other side of the membrane. The single-wall carbon nanotube growth may occur predominately on the low-pressure side of the membrane or, in a different embodiment of the invention, may occur predominately in between the catalyst and the membrane. The invention also relates to an apparatus used with the carbon vapor deposition process.

  8. Continuous growth of single-wall carbon nanotubes using chemical vapor deposition

    DOE Patents [OSTI]

    Grigorian, Leonid; Hornyak, Louis; Dillon, Anne C; Heben, Michael J

    2014-09-23T23:59:59.000Z

    The invention relates to a chemical vapor deposition process for the continuous growth of a carbon single-wall nanotube where a carbon-containing gas composition is contacted with a porous membrane and decomposed in the presence of a catalyst to grow single-wall carbon nanotube material. A pressure differential exists across the porous membrane such that the pressure on one side of the membrane is less than that on the other side of the membrane. The single-wall carbon nanotube growth may occur predominately on the low-pressure side of the membrane or, in a different embodiment of the invention, may occur predominately in between the catalyst and the membrane. The invention also relates to an apparatus used with the carbon vapor deposition process.

  9. Growth of FePt encapsulated carbon nanotubes by thermal chemical vapor deposition

    SciTech Connect (OSTI)

    Fujiwara, Yuji, E-mail: fujiwara@phen.mie-u.ac.jp; Kaneko, Tetsuya; Hori, Kenta; Takase, Sho; Sato, Hideki; Maeda, Kohji; Kobayashi, Tadashi [Graduate School of Engineering, Mie University, Kurima-machiya-cho 1577, Tsu 514-8507 (Japan); Kato, Takeshi; Iwata, Satoshi [Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Jimbo, Mutsuko [Department of Electrical and Electronic Engineering, Daido University, Takiharu-cho 10-3, Minami-ku, Nagoya 457-8530 (Japan)

    2014-03-15T23:59:59.000Z

    FePt encapsulated carbon nanotubes (CNTs) were grown by thermal chemical vapor deposition using an Fe/Pt bilayer catalyst. The CNTs were grown according to the base growth model. Selected area electron diffraction results revealed that the encapsulated particles were A1-FePt, L1{sub 0}-FePt, and Fe{sub 3}PtC. The crystal structures of particles found at the root parts of CNTs were not able to be identified, however. The layered structure of catalytic films seemed to be responsible for the difference in Pt content between particles found at tip and root parts of CNTs. Approximately 60% of CNTs grown at 800?°C had particles at their tip parts, compared to only 30% when the growth temperature was 700?°C, indicating that higher process temperatures promote particle encapsulation in CNTs.

  10. Cooperative Island Growth of Large Area Single-Crystal Graphene by Chemical Vapor Deposition on Cu

    SciTech Connect (OSTI)

    Regmi, Murari [Oak Ridge National Laboratory (ORNL); Rouleau, Christopher [Oak Ridge National Laboratory (ORNL); Puretzky, Alexander A [ORNL; Ivanov, Ilia N [ORNL; Geohegan, David B [ORNL; Chen, Jihua [ORNL; Eastman, Jeffrey [Argonne National Laboratory (ANL); Eres, Gyula [ORNL

    2014-01-01T23:59:59.000Z

    We describe a two-step approach for suppressing nucleation of graphene on Cu using chemical vapor deposition. In the first step, as received Cu foils are oxidized in air at temperatures up to 500 C to remove surface impurities and to induce the regrowth of Cu grains during subsequent annealing in H2 flow at 1040 C prior to graphene growth. In the second step, transient reactant cooling is performed by using a brief Ar pulse at the onset of growth to induce collisional deactivation of the carbon growth species. The combination of these two steps results in a three orders of magnitude reduction in the graphene nucleation density, enabling the growth of millimeter-size single crystal graphene grains. A kinetic model shows that suppressing nucleation promotes a cooperative island growth mode that favors the formation of large area single crystal graphene, and it is accompanied by a roughly 3 orders of magnitude increase in the reactive sticking probability of methane compared to that in random nucleation growth.

  11. Low temperature junction growth using hot-wire chemical vapor deposition

    DOE Patents [OSTI]

    Wang, Qi; Page, Matthew; Iwaniczko, Eugene; Wang, Tihu; Yan, Yanfa

    2014-02-04T23:59:59.000Z

    A system and a process for forming a semi-conductor device, and solar cells (10) formed thereby. The process includes preparing a substrate (12) for deposition of a junction layer (14); forming the junction layer (14) on the substrate (12) using hot wire chemical vapor deposition; and, finishing the semi-conductor device.

  12. Controlling single and few-layer graphene crystals growth in a solid carbon source based chemical vapor deposition

    SciTech Connect (OSTI)

    Papon, Remi; Sharma, Subash; Shinde, Sachin M.; Vishwakarma, Riteshkumar; Tanemura, Masaki [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Center for Fostering Young and Innovative Researchers, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555 (Japan)

    2014-09-29T23:59:59.000Z

    Here, we reveal the growth process of single and few-layer graphene crystals in the solid carbon source based chemical vapor deposition (CVD) technique. Nucleation and growth of graphene crystals on a polycrystalline Cu foil are significantly affected by the injection of carbon atoms with pyrolysis rate of the carbon source. We observe micron length ribbons like growth front as well as saturated growth edges of graphene crystals depending on growth conditions. Controlling the pyrolysis rate of carbon source, monolayer and few-layer crystals and corresponding continuous films are obtained. In a controlled process, we observed growth of large monolayer graphene crystals, which interconnect and merge together to form a continuous film. On the other hand, adlayer growth is observed with an increased pyrolysis rate, resulting few-layer graphene crystal structure and merged continuous film. The understanding of monolayer and few-layer crystals growth in the developed CVD process can be significant to grow graphene with controlled layer numbers.

  13. Microwave plasma enhanced chemical vapor deposition of nanocrystalline diamond films by bias-enhanced nucleation and bias-enhanced growth

    SciTech Connect (OSTI)

    Chu, Yueh-Chieh [Institute of Microelectronics, National Cheng Kung University No.1, University Road, Tainan 701, Taiwan (China); Tzeng, Yonhua, E-mail: tzengyo@mail.ncku.edu.tw [Institute of Microelectronics, National Cheng Kung University No.1, University Road, Tainan 701, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University No.1, University Road, Tainan 701, Taiwan (China); Auciello, Orlando [Department of Materials Science and Engineering and Bioengineering, University of Texas in Dallas, 800 W. Campbell Rd, Richardson, Texas 75080 (United States)

    2014-01-14T23:59:59.000Z

    Effects of biasing voltage-current relationship on microwave plasma enhanced chemical vapor deposition of ultrananocrystalline diamond (UNCD) films on (100) silicon in hydrogen diluted methane by bias-enhanced nucleation and bias-enhanced growth processes are reported. Three biasing methods are applied to study their effects on nucleation, growth, and microstructures of deposited UNCD films. Method A employs 320?mA constant biasing current and a negative biasing voltage decreasing from ?490?V to ?375?V for silicon substrates pre-heated to 800?°C. Method B employs 400?mA constant biasing current and a decreasing negative biasing voltage from ?375?V to ?390?V for silicon pre-heated to 900?°C. Method C employs ?350?V constant biasing voltage and an increasing biasing current up to 400?mA for silicon pre-heated to 800?°C. UNCD nanopillars, merged clusters, and dense films with smooth surface morphology are deposited by the biasing methods A, B, and C, respectively. Effects of ion energy and flux controlled by the biasing voltage and current, respectively, on nucleation, growth, microstructures, surface morphologies, and UNCD contents are confirmed by scanning electron microscopy, high-resolution transmission-electron-microscopy, and UV Raman scattering.

  14. Vapor deposition of hardened niobium

    DOE Patents [OSTI]

    Blocher, Jr., John M. (Columbus, OH); Veigel, Neil D. (Columbus, OH); Landrigan, Richard B. (Columbus, OH)

    1983-04-19T23:59:59.000Z

    A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

  15. Process sensing and metrology in gate oxide growth by rapid thermal chemical vapor deposition from SiH4 and N2O

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Process sensing and metrology in gate oxide growth by rapid thermal chemical vapor deposition from for Advanced Electronic Materials Processing, North Carolina State University, Raleigh, North Carolina 27695-7920 Received 7 January 1999; accepted 21 May 1999 Active sampling mass spectrometry has been used for process

  16. Thermodynamic analysis and growth of ZrO2 by chloride chemical vapor deposition

    E-Print Network [OSTI]

    Anderson, Timothy J.

    reaction [9­12], and simple chamber designs (e.g., vertical, cold-wall, axisymmetric chamber) to deposit flow injector can be used. A stagnation plane flow injector (for vertical, cold-wall CVD chambers homogeneous nucleation and/ or reactor wall deposition. For example, Holstein [17] de- monstrated that at high

  17. Vapor deposition of thin films

    DOE Patents [OSTI]

    Smith, David C. (Los Alamos, NM); Pattillo, Stevan G. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Sattelberger, Alfred P. (Los Alamos, NM)

    1992-01-01T23:59:59.000Z

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  18. Growth of Large-Area Aligned Molybdenum Nanowires by High Temperature Chemical Vapor Deposition: Synthesis, Growth Mechanism, and Device Application

    E-Print Network [OSTI]

    Wang, Zhong L.

    , thermogravimetry, and differential scanning calorimetry analysis, as well as structure analysis by electron on the decomposition of MoO2 vapors through condensation of its vapor at high substrate temperatures. The aligned nanowires with H2 gas.6d-f However, the reduction process degrades the crystal- linity of the nanowires

  19. Vacuum vapor deposition gun assembly

    DOE Patents [OSTI]

    Zeren, Joseph D. (Boulder, CO)

    1985-01-01T23:59:59.000Z

    A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  20. Epitaxial growth of aligned AlGalnN nanowires by metal-organic chemical vapor deposition

    DOE Patents [OSTI]

    Han, Jung (Woodbridge, CT); Su, Jie (New Haven, CT)

    2008-08-05T23:59:59.000Z

    Highly ordered and aligned epitaxy of III-Nitride nanowires is demonstrated in this work. <1010> M-axis is identified as a preferential nanowire growth direction through a detailed study of GaN/AlN trunk/branch nanostructures by transmission electron microscopy. Crystallographic selectivity can be used to achieve spatial and orientational control of nanowire growth. Vertically aligned (Al)GaN nanowires are prepared on M-plane AlN substrates. Horizontally ordered nanowires, extending from the M-plane sidewalls of GaN hexagonal mesas or islands demonstrate new opportunities for self-aligned nanowire devices, interconnects, and networks.

  1. Nucleation and growth of carbon nanotubes by microwave plasma chemical vapor deposition

    E-Print Network [OSTI]

    at a very rapid and constant rate 100 nm/s that decreases sharply after the catalyst Co particles become. Experi- ments performed, mostly on individual nanotubes, show that they have extraordinary electrical conditions such as substrate, catalyst, feed gas, and temperature, the growth model proposed by several

  2. Chemical vapor deposition of functionalized isobenzofuran polymers

    E-Print Network [OSTI]

    Olsson, Ylva Kristina

    2007-01-01T23:59:59.000Z

    This thesis develops a platform for deposition of polymer thin films that can be further tailored by chemical surface modification. First, we explore chemical vapor deposition of functionalized isobenzofuran films using ...

  3. Direct growth of few-layer graphene on 6H-SiC and 3C-SiC/Si via propane chemical vapor deposition

    SciTech Connect (OSTI)

    Michon, A.; Vezian, S.; Portail, M. [CNRS-CRHEA, Rue Bernard Gregory, 06560 Valbonne (France); Ouerghi, A. [CNRS-LPN, Route de Nozay, 91460 Marcoussis (France); Zielinski, M.; Chassagne, T. [NOVASiC, Savoie Technolac, Arche Bat 4, BP267, 73375 Le Bourget du Lac (France)

    2010-10-25T23:59:59.000Z

    We propose to grow graphene on SiC by a direct carbon feeding through propane flow in a chemical vapor deposition reactor. X-ray photoemission and low energy electron diffraction show that propane allows to grow few-layer graphene (FLG) on 6H-SiC(0001). Surprisingly, FLG grown on (0001) face presents a rotational disorder similar to that observed for FLG obtained by annealing on (000-1) face. Thanks to a reduced growth temperature with respect to the classical SiC annealing method, we have also grown FLG/3C-SiC/Si(111) in a single growth sequence. This opens the way for large-scale production of graphene-based devices on silicon substrate.

  4. Effects of pressure, temperature, and hydrogen during graphene growth on SiC(0001) using propane-hydrogen chemical vapor deposition

    SciTech Connect (OSTI)

    Michon, A.; Vezian, S.; Roudon, E.; Lefebvre, D.; Portail, M. [CNRS-CRHEA, Rue Bernard Gregory, 06560 Valbonne (France)] [CNRS-CRHEA, Rue Bernard Gregory, 06560 Valbonne (France); Zielinski, M.; Chassagne, T. [NOVASiC, Savoie Technolac, Arche Bat 4, BP267, 73375 Le Bourget du Lac (France)] [NOVASiC, Savoie Technolac, Arche Bat 4, BP267, 73375 Le Bourget du Lac (France)

    2013-05-28T23:59:59.000Z

    Graphene growth from a propane flow in a hydrogen environment (propane-hydrogen chemical vapor deposition (CVD)) on SiC differentiates from other growth methods in that it offers the possibility to obtain various graphene structures on the Si-face depending on growth conditions. The different structures include the (6{radical}3 Multiplication-Sign 6{radical}3)-R30 Degree-Sign reconstruction of the graphene/SiC interface, which is commonly observed on the Si-face, but also the rotational disorder which is generally observed on the C-face. In this work, growth mechanisms leading to the formation of the different structures are studied and discussed. For that purpose, we have grown graphene on SiC(0001) (Si-face) using propane-hydrogen CVD at various pressure and temperature and studied these samples extensively by means of low energy electron diffraction and atomic force microscopy. Pressure and temperature conditions leading to the formation of the different structures are identified and plotted in a pressure-temperature diagram. This diagram, together with other characterizations (X-ray photoemission and scanning tunneling microscopy), is the basis of further discussions on the carbon supply mechanisms and on the kinetics effects. The entire work underlines the important role of hydrogen during growth and its effects on the final graphene structure.

  5. Chemical vapor deposition of antimicrobial polymer coatings

    E-Print Network [OSTI]

    Martin, Tyler Philip, 1977-

    2007-01-01T23:59:59.000Z

    There is large and growing interest in making a wide variety of materials and surfaces antimicrobial. Initiated chemical vapor deposition (iCVD), a solventless low-temperature process, is used to form thin films of polymers ...

  6. Chemical vapor deposition of mullite coatings

    DOE Patents [OSTI]

    Sarin, Vinod (Lexington, MA); Mulpuri, Rao (Boston, MA)

    1998-01-01T23:59:59.000Z

    This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

  7. Chemical vapor deposition of epitaxial silicon

    DOE Patents [OSTI]

    Berkman, Samuel (Florham Park, NJ)

    1984-01-01T23:59:59.000Z

    A single chamber continuous chemical vapor deposition (CVD) reactor is described for depositing continuously on flat substrates, for example, epitaxial layers of semiconductor materials. The single chamber reactor is formed into three separate zones by baffles or tubes carrying chemical source material and a carrier gas in one gas stream and hydrogen gas in the other stream without interaction while the wafers are heated to deposition temperature. Diffusion of the two gas streams on heated wafers effects the epitaxial deposition in the intermediate zone and the wafers are cooled in the final zone by coolant gases. A CVD reactor for batch processing is also described embodying the deposition principles of the continuous reactor.

  8. Vapor-deposited porous films for energy conversion

    DOE Patents [OSTI]

    Jankowski, Alan F.; Hayes, Jeffrey P.; Morse, Jeffrey D.

    2005-07-05T23:59:59.000Z

    Metallic films are grown with a "spongelike" morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous and open porosity on the submicron scale. The stabilization of the spongelike morphology is found over a limited range of the sputter deposition parameters, that is, of working gas pressure and substrate temperature. This spongelike morphology is an extension of the features as generally represented in the classic zone models of growth for physical vapor deposits. Nickel coatings were deposited with working gas pressures up 4 Pa and for substrate temperatures up to 1000 K. The morphology of the deposits is examined in plan and in cross section views with scanning electron microscopy (SEM). The parametric range of gas pressure and substrate temperature (relative to absolute melt point) under which the spongelike metal deposits are produced appear universal for other metals including gold, silver, and aluminum.

  9. Epitaxial growth of BaTiO3 thin films at 600 C by metalorganic chemical vapor deposition

    E-Print Network [OSTI]

    Wang, Zhong L.

    with an a-axis perpendicular to the substrate plane. Nanoscale energy dispersive x-ray spectrometry processes include deposition over large areas, high throughput, and uniform coverage of nonplanar shapes by a plasma-enhanced MOCVD pro- cess. It is not known if the added energy from the plasma generates structural

  10. Growth of crystalline X-Sic on Si at reduced temperatures by chemical vapor deposition from `silacycllobutane

    E-Print Network [OSTI]

    Steckl, Andrew J.

    gas and the de- simple hydrocarbon, such as propane. The Si-bearing gas is creased operational hazards growth has been reported to pro- duce both monocrystalline layers' at 750 "C and amor- phous layers9 over

  11. Polymer electrolyte fuel cell electrodes grown by vapor deposition techniques Pascal Brault*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Polymer electrolyte fuel cell electrodes grown by vapor deposition techniques Pascal Brault Abstract: Polymer fuel cell electrode growth using vapor deposition techniques is reviewed. The supports process: sputtering, CVD, PECVD, MOCVD. In each case, up-to-date fuel cell performances are highlighted

  12. OPTIMAL DESIGN OF A HIGH PRESSURE ORGANOMETALLIC CHEMICAL VAPOR DEPOSITION REACTOR

    E-Print Network [OSTI]

    OPTIMAL DESIGN OF A HIGH PRESSURE ORGANOMETALLIC CHEMICAL VAPOR DEPOSITION REACTOR K.J. BACHMANN vapor deposition (HPOMCVD) reactor for use in thin film crystal growth. The advantages of such a reactor decomposition pressures and increased control over local stoichiometry and defect formation. While we focus here

  13. Hydrogen effect on near-atmospheric nitrogen plasma assisted chemical vapor deposition of GaN film growth

    SciTech Connect (OSTI)

    Nagata, T.; Haemori, M.; Sakuma, Y.; Chikyow, T. [Advanced Electronic Materials Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Anzai, J.; Uehara, T. [Sekisui Chemical Co., Ltd., Wadai, Tsukuba, Ibaraki 300-4292 (Japan)

    2009-03-15T23:59:59.000Z

    The effect of hydrogen on near-atmospheric nitrogen plasma and low temperature growth of GaN thin film was investigated. To investigate nitrogen plasma diluted with hydrogen, optical emission spectroscopy (OES) was employed. OES indicates that hydrogen enhances the generation of the nitrogen first positive system and first negative systems by providing an additional kinetic pathway. The plasma also decomposed triethylgallium and generated Ga ions even at room temperature. Using this plasma, GaN film grew on sapphire substrate epitaxially at growth temperatures of above 170 deg. C and crystallized at 55 deg. C.

  14. Thermal decomposition of ethanol and growth of vertically aligned single-walled carbon nanotubes by alcohol catalytic chemical vapor deposition

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Thermal decomposition of ethanol and growth of vertically aligned single-walled carbon nanotubes. In this study, we have investigated the thermal decomposition of ethanol at various temperatures, as well National Meeting, San Francisco, CA, September 10-14, 2006 1/1 PRES 29 - Thermal decomposition of ethanol

  15. The Growth of InGaAsN for High Efficiency Solar Cells by Metalorganic Chemical Vapor Deposition

    SciTech Connect (OSTI)

    ALLERMAN,ANDREW A.; BANKS,JAMES C.; GEE,JAMES M.; JONES,ERIC D.; KURTZ,STEVEN R.

    1999-09-16T23:59:59.000Z

    InGaAsN alloys are a promising material for increasing the efficiency of multi-junction solar cells now used for satellite power systems. However, the growth of these dilute N containing alloys has been challenging with further improvements in material quality needed before the solar cell higher efficiencies are realized. Nitrogen/V ratios exceeding 0.981 resulted in lower N incorporation and poor surface morphologies. The growth rate was found to depend on not only the total group III transport for a fixed N/V ratio but also on the N/V ratio. Carbon tetrachloride and dimethylzinc were effective for p-type doping. Disilane was not an effective n-type dopant while SiCl4 did result in n-type material but only a narrow range of electron concentrations (2-5e17cm{sup -3}) were achieved.

  16. Elemental diffusion during the droplet epitaxy growth of In(Ga)As/GaAs(001) quantum dots by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Chen, Z. B.; Chen, B.; Wang, Y. B.; Liao, X. Z., E-mail: xiaozhou.liao@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Lei, W. [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009 (Australia); Tan, H. H.; Jagadish, C. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Zou, J. [Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, QLD 4072 (Australia); Ringer, S. P. [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia)

    2014-01-13T23:59:59.000Z

    Droplet epitaxy is an important method to produce epitaxial semiconductor quantum dots (QDs). Droplet epitaxy of III-V QDs comprises group III elemental droplet deposition and the droplet crystallization through the introduction of group V elements. Here, we report that, in the droplet epitaxy of InAs/GaAs(001) QDs using metal-organic chemical vapor deposition, significant elemental diffusion from the substrate to In droplets occurs, resulting in the formation of In(Ga)As crystals, before As flux is provided. The supply of As flux suppresses the further elemental diffusion from the substrate and promotes surface migration, leading to large island formation with a low island density.

  17. Apparatus and method for photochemical vapor deposition

    DOE Patents [OSTI]

    Jackson, Scott C. (Wilmington, DE); Rocheleau, Richard E. (Wilmington, DE)

    1987-03-31T23:59:59.000Z

    A photochemical vapor deposition apparatus includes a reactor housing having a window in one wall above a reaction chamber in the housing. A transparent curtain divides the reaction chamber into a reaction zone and a flush zone. At least one substrate is mounted in the reaction zone in light communication with the window so that ultraviolet radiation may penetrate through the window into the reaction zone. The window is kept clear by a gas flowing through the flush zone.

  18. Chemical vapor deposition of group IIIB metals

    DOE Patents [OSTI]

    Erbil, A.

    1989-11-21T23:59:59.000Z

    Coatings of Group IIIB metals and compounds thereof are formed by chemical vapor deposition, in which a heat decomposable organometallic compound of the formula given in the patent where M is a Group IIIB metal, such as lanthanum or yttrium and R is a lower alkyl or alkenyl radical containing from 2 to about 6 carbon atoms, with a heated substrate which is above the decomposition temperature of the organometallic compound. The pure metal is obtained when the compound of the formula 1 is the sole heat decomposable compound present and deposition is carried out under nonoxidizing conditions. Intermetallic compounds such as lanthanum telluride can be deposited from a lanthanum compound of formula 1 and a heat decomposable tellurium compound under nonoxidizing conditions.

  19. All graphene electromechanical switch fabricated by chemical vapor deposition

    E-Print Network [OSTI]

    Milaninia, Kaveh M.

    We demonstrate an electromechanical switch comprising two polycrystalline graphene films; each deposited using ambient pressure chemical vapor deposition. The top film is pulled into electrical contact with the bottom film ...

  20. Metal film deposition by laser breakdown chemical vapor deposition

    SciTech Connect (OSTI)

    Jervis, T.R.

    1985-01-01T23:59:59.000Z

    Dielectric breakdown of gas mixtures can be used to deposit homogeneous thin films by chemical vapor deposition with appropriate control of flow and pressure conditions to suppress gas phase nucleation and particle formation. Using a pulsed CO/sub 2/ laser operating at 10.6 microns where there is no significant resonant absorption in any of the source gases, we have succeeded in depositing homogeneous films from several gas phase precursors by gas phase laser pyrolysis. Nickel and molybdenum from the respective carbonyls and tungsten from the hexafluoride have been examined to date. In each case the gas precursor is buffered to reduce the partial pressure of the reactants and to induce breakdown. The films are spectrally reflective and uniform over a large area. Films have been characterized by Auger electron spectroscopy, x-ray diffraction, pull tests, and resistivity measurements. The highest quality films have resulted from the nickel depositions. Detailed x-ray diffraction analysis of these films yields a very small domain size (approx. 50 A) consistent with rapid quenching from the gas phase reaction zone. This analysis also shows nickel carbide formation consistent with the temperature of the reaction zone and the Auger electron spectroscopy results which show some carbon and oxygen incorporation (8% and 1% respectively). Gas phase transport and condensation of the molybdenum carbonyl results in substantial carbon and oxygen contamination of the molybdenum films requiring heated substrates, a requirement not consistent with the goals of the program to maximize the quench rate of the deposition. Results from tungsten deposition experiments representing a reduction chemistry instead of the decomposition chemistry involved in the carbonyl experiments are also reported.

  1. Direct Growth Graphene on Cu Nanoparticles by Chemical Vapor Deposition as Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine

    E-Print Network [OSTI]

    Xu, Shicai; Jiang, Shouzhen; Wang, Jihua; Wei, Jie; Xu, Shida; Liu, Hanping

    2015-01-01T23:59:59.000Z

    We present a graphene/Cu nanoparticle hybrids (G/CuNPs) system as a surface-enhanced Raman scattering (SERS) substrate for adenosine detection. The Cu nanoparticles wrapped around a monolayer graphene shell were directly synthesized on flat quartz by chemical vapor deposition in a mixture of methane and hydrogen. The G/CuNPs showed an excellent SERS enhancement activity for adenosine. The minimum detected concentration of the adenosine in serum was demonstrated as low as 5 nM, and the calibration curve showed a good linear response from 5 to 500 nM. The capability of SERS detection of adenosine in real normal human urine samples based on G/CuNPs was also investigated and the characteristic peaks of adenosine were still recognizable. The reproducible and the ultrasensitive enhanced Raman signals could be due to the presence of an ultrathin graphene layer. The graphene shell was able to enrich and fix the adenosine molecules, which could also efficiently maintain chemical and optical stability of G/CuNPs. Based...

  2. Ge incorporation inside 4H-SiC during Homoepitaxial growth by chemical vapor

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Ge incorporation inside 4H-SiC during Homoepitaxial growth by chemical vapor deposition. Kassem Ilmenau (Germany) Abstract. In this work, we report on the addition of GeH4 gas during homoepitaxial growth of 4H-SiC by chemical vapour deposition. Ge introduction does not affect dramatically the surface

  3. InGaN/GaN multi-quantum well and LED growth on wafer-bonded sapphire-on-polycrystalline AlN substrates by metalorganic chemical vapor deposition.

    SciTech Connect (OSTI)

    Crawford, Mary Hagerott; Olson, S. M. (Aonex Technologies Inc., Pasadena, CA); Banas, M.; Park, Y. -B. (Aonex Technologies Inc., Pasadena, CA); Ladous, C. (Aonex Technologies Inc., Pasadena, CA); Russell, Michael J.; Thaler, Gerald; Zahler, J. M. (Aonex Technologies Inc., Pasadena, CA); Pinnington, T. (Aonex Technologies Inc., Pasadena, CA); Koleske, Daniel David; Atwater, Harry A. (Aonex Technologies Inc., Pasadena, CA)

    2008-06-01T23:59:59.000Z

    We report growth of InGaN/GaN multi-quantum well (MQW) and LED structures on a novel composite substrate designed to eliminate the coefficient of thermal expansion (CTE) mismatch problems which impact GaN growth on bulk sapphire. To form the composite substrate, a thin sapphire layer is wafer-bonded to a polycrystalline aluminum nitride (P-AlN) support substrate. The sapphire layer provides the epitaxial template for the growth; however, the thermo-mechanical properties of the composite substrate are determined by the P-AlN. Using these substrates, thermal stresses associated with temperature changes during growth should be reduced an order of magnitude compared to films grown on bulk sapphire, based on published CTE data. In order to test the suitability of the substrates for GaN LED growth, test structures were grown by metalorganic chemical vapor deposition (MOCVD) using standard process conditions for GaN growth on sapphire. Bulk sapphire substrates were included as control samples in all growth runs. In situ reflectance monitoring was used to compare the growth dynamics for the different substrates. The material quality of the films as judged by X-ray diffraction (XRD), photoluminescence and transmission electron microscopy (TEM) was similar for the composite substrate and the sapphire control samples. Electroluminescence was obtained from the LED structure grown on a P-AlN composite substrate, with a similar peak wavelength and peak width to the control samples. XRD and Raman spectroscopy results confirm that the residual strain in GaN films grown on the composite substrates is dramatically reduced compared to growth on bulk sapphire substrates.

  4. Chemical vapor deposition of organosilicon and sacrificial polymer thin films

    E-Print Network [OSTI]

    Casserly, Thomas Bryan

    2005-01-01T23:59:59.000Z

    Chemical vapor deposition (CVD) produced films for a wide array of applications from a variety of organosilicon and organic precursors. The structure and properties of thin films were controlled by varying processing ...

  5. Initiated chemical vapor deposition of functional polyacrylic thin films

    E-Print Network [OSTI]

    Mao, Yu, 1975-

    2005-01-01T23:59:59.000Z

    Initiated chemical vapor deposition (iCVD) was explored as a novel method for synthesis of functional polyacrylic thin films. The process introduces a peroxide initiator, which can be decomposed at low temperatures (<200?C) ...

  6. Enabling integration of vapor-deposited polymer thin films

    E-Print Network [OSTI]

    Petruczok, Christy D. (Christy Danielle)

    2014-01-01T23:59:59.000Z

    Initiated Chemical Vapor Deposition (iCVD) is a versatile, one-step process for synthesizing conformal and functional polymer thin films on a variety of substrates. This thesis emphasizes the development of tools to further ...

  7. Cobalt Ultrathin Film Catalyzed Ethanol Chemical Vapor Deposition of Single-Walled Carbon Nanotubes

    E-Print Network [OSTI]

    Hone, James

    Cobalt Ultrathin Film Catalyzed Ethanol Chemical Vapor Deposition of Single-Walled Carbon Nanotubes (SWNTs) using a cobalt ultrathin film (1 nm) as the catalyst and ethanol as carbon feedstock flow during the growth. The trace amount of self-contained water (0.2-5 wt %) in ethanol may act

  8. The development of chemically vapor deposited mullite coatings for the corrosion protection of SiC

    SciTech Connect (OSTI)

    Auger, M.; Hou, P.; Sengupta, A.; Basu, S.; Sarin, V. [Boston Univ., MA (United States)

    1998-05-01T23:59:59.000Z

    Crystalline mullite coatings have been chemically vapor deposited onto SiC substrates to enhance the corrosion and oxidation resistance of the substrate. Current research has been divided into three distinct areas: (1) Development of the deposition processing conditions for increased control over coating`s growth rate, microstructure, and morphology; (2) Analysis of the coating`s crystal structure and stability; (3) The corrosion resistance of the CVD mullite coating on SiC.

  9. Chemical vapor deposition thin films as biopassivation coatings and directly patternable dielectrics

    E-Print Network [OSTI]

    Pryce Lewis, Hilton G. (Hilton Gavin), 1973-

    2001-01-01T23:59:59.000Z

    Organosilicon thin films deposited by pulsed plasma-enhanced chemical vapor deposition (PPECVD) and hot-filament chemical vapor deposition (HFCVD) were investigated as potential biopassivation coatings for neural probes. ...

  10. Fabrication of solid oxide fuel cell by electrochemical vapor deposition

    DOE Patents [OSTI]

    Brian, Riley (Willimantic, CT); Szreders, Bernard E. (Oakdale, CT)

    1989-01-01T23:59:59.000Z

    In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (approximately 1100.degree.-1300.degree. C.) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20-50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

  11. Fabrication of solid oxide fuel cell by electrochemical vapor deposition

    DOE Patents [OSTI]

    Riley, B.; Szreders, B.E.

    1988-04-26T23:59:59.000Z

    In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (/approximately/1100/degree/ /minus/ 1300/degree/C) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20--50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

  12. Chemical vapor deposition of aluminum oxide

    DOE Patents [OSTI]

    Gordon, Roy (Cambridge, MA); Kramer, Keith (Cleveland, OH); Liu, Xinye (Cambridge, MA)

    2000-01-01T23:59:59.000Z

    An aluminum oxide film is deposited on a heated substrate by CVD from one or more alkylaluminum alkoxide compounds having composition R.sub.n Al.sub.2 (OR').sub.6-n, wherein R and R' are alkyl groups and n is in the range of 1 to 5.

  13. Optical properties of chemical-vapor-deposited diamond films

    SciTech Connect (OSTI)

    Bi, X.X.; Eklund, P.C.; Zhang, J.G.; Rao, A.M. (Department of Physics and Astronomy, University of Kentucky, Lexington, KY (USA)); Perry, T.A.; Beetz, C.P. Jr. (Physics Department, General Motors Research Laboratory, Warren, MI (USA))

    1990-04-01T23:59:59.000Z

    Results of room-temperature optical studies on {similar to}10 micron thick, free-standing diamond films are reported. The films were grown on Si(100) substrates by hot filament-assisted chemical vapor deposition (CVD) from a methane/hydrogen mixture. The as-grown, free surface of the films exhibited a surface roughness of scale {sigma}{similar to}0.2 to 5 microns, depending on the methane/hydrogen mixture, which introduces significant optical scattering loss for frequencies greater than 0.5 eV. Specular reflection and transmission spectra in the range 0.01--10 eV were collected. Below the threshold for interband adsorption near {similar to}5 eV, the films studied behaved approximately as thin parallel plates of refractive index 2.4, with the rough free surface leading to increasingly larger loss of specular transmission/reflection with decreasing wavelength. Structure in the mid-infrared transmission spectra was observed and attributed to disorder-induced one-phonon absorption, intrinsic multi-phonon absorption, and infrared active --C--H{sub 2} stretching modes. The strength of the C--H band was observed to increase with increasing methane pressure in the growth chamber. At 5.3 eV, the onset of interband absorption was observed, in good agreement with the value of the indirect bandgap in type IIa (intrinsic) diamond.

  14. Amine functionalization by initiated chemical vapor deposition (iCVD) for interfacial adhesion and film cohesion

    E-Print Network [OSTI]

    Xu, Jingjing, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Amine functional polymer thin films provide a versatile platform for subsequent functionalization because of their diverse reactivity. Initiated chemical vapor deposition (iCVD) is a polymer chemical vapor deposition ...

  15. Growth of single crystalline GaN thin films on Si,,111... substrates by high vacuum metalorganic chemical vapor deposition using a single

    E-Print Network [OSTI]

    Boo, Jin-Hyo

    Growth of single crystalline GaN thin films on Si,,111... substrates by high vacuum metalorganic; published 20 August 2004 Hexagonal GaN thin films were grown on Si 111 substrates using single molecular precursor of diethylazidogallium methylhydrazine adduct, (Et)2Ga N3)HzMe], with the objectives of reducing

  16. Molecular-jet chemical vapor deposition of SiC

    SciTech Connect (OSTI)

    Lubben, D.; Jellison, G.E.; Modine, F.A.

    1995-09-01T23:59:59.000Z

    SiC films have been deposited by molecular-jet chemical vapor deposition (MJCVD) on Si(001) substrates. Methylsilane (MS) diluted in He was used as a precursor for deposition under conditions which produced a MS molecular beam with 0.365 eV translational energy. Films grown at temperatures between 1000 and 1150 C and above {approx}1200 C were single crystal as judged by electron channeling, while those grown at intermediate temperatures were polycrystalline. Films grown at lower temperatures generally had a smoother surface morphology for moderate thicknesses, although all films showed at least some degree of faceting. The best thick films, up to 4 {mu}m, were obtained for substrate temperatures of {approx}1210 C under flow conditions which produced a deposition rate of {approx}1200 {angstrom} per minute.

  17. Initiated chemical vapor deposition of polymeric thin films : mechanism and applications

    E-Print Network [OSTI]

    Chan, Kelvin, Ph. D. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    Initiated chemical vapor deposition (iCVD) is a novel technique for depositing polymeric thin films. It is able to deposit thin films of application-specific polymers in one step without using any solvents. Its uniqueness ...

  18. Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report)

    SciTech Connect (OSTI)

    Panitz, J.K.; Hsu, W.L.; Tallant, D.R.; McMaster, M.; Fox, C.; Staley, D.

    1995-12-01T23:59:59.000Z

    Densifying non-mined diamond powder precursors with diamond produced by chemical vapor infiltration (CVI) is an attractive approach for forming thick diamond deposits that avoids many potential manufacturability problems associated with predominantly chemical vapor deposition (CVD) processes. The authors developed techniques for forming diamond powder precursors and densified these precursors in a hot filament-assisted reactor and a microwave plasma-assisted reactor. Densification conditions were varied following a fractional factorial statistical design. A number of conclusions can be drawn as a result of this study. High density diamond powder green bodies that contain a mixture of particle sizes solidify more readily than more porous diamond powder green bodies with narrow distributions of particle sizes. No composite was completely densified although all of the deposits were densified to some degree. The hot filament-assisted reactor deposited more material below the exterior surface, in the interior of the powder deposits; in contrast, the microwave-assisted reactor tended to deposit a CVD diamond skin over the top of the powder precursors which inhibited vapor phase diamond growth in the interior of the powder deposits. There were subtle variations in diamond quality as a function of the CVI process parameters. Diamond and glassy carbon tended to form at the exterior surface of the composites directly exposed to either the hot filament or the microwave plasma. However, in the interior, e.g. the powder/substrate interface, diamond plus diamond-like-carbon formed. All of the diamond composites produced were grey and relatively opaque because they contained flawed diamond, diamond-like-carbon and glassy carbon. A large amount of flawed and non-diamond material could be removed by post-CVI oxygen heat treatments. Heat treatments in oxygen changed the color of the composites to white.

  19. Method of physical vapor deposition of metal oxides on semiconductors

    DOE Patents [OSTI]

    Norton, David P. (Knoxville, TN)

    2001-01-01T23:59:59.000Z

    A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

  20. The aging of tungsten filaments and its effect on wire surface kinetics in hot-wire chemical vapor deposition

    E-Print Network [OSTI]

    Atwater, Harry

    desorption kinetics. In particular, the Si signal exhibits a high temperature activation energy consistent vapor deposition growth have been measured by quadrupole mass spectrometry. New wires produce Si with previous measurements; the activation energy for the SiH3 signal suggests its formation is catalyzed. Aged

  1. Chemical Vapor Deposited Zinc Sulfide. SPIE Press Monograph

    SciTech Connect (OSTI)

    McCloy, John S.; Tustison, Randal W.

    2013-04-22T23:59:59.000Z

    Zinc sulfide has shown unequaled utility for infrared windows that require a combination of long-wavelength infrared transparency, mechanical durability, and elevated-temperature performance. This book reviews the physical properties of chemical vapor deposited ZnS and their relationship to the CVD process that produced them. An in-depth look at the material microstructure is included, along with a discussion of the material's optical properties. Finally, because the CVD process itself is central to the development of this material, a brief history is presented.

  2. Unusual thermopower of inhomogeneous graphene grown by chemical vapor deposition

    SciTech Connect (OSTI)

    Nam, Youngwoo, E-mail: youngwoo.nam@chalmers.se [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Sun, Jie; Lindvall, Niclas; Yurgens, August [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Jae Yang, Seung; Rae Park, Chong [Department of Materials Science and Engineering, Seoul National University, Seoul 151-747 (Korea, Republic of); Woo Park, Yung [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-01-13T23:59:59.000Z

    We report on thermopower (TEP) and resistance measurements of inhomogeneous graphene grown by chemical vapor deposition (CVD). Unlike the conventional resistance of pristine graphene, the gate-dependent TEP shows a large electron-hole asymmetry. This can be accounted for by inhomogeneity of the CVD-graphene where individual graphene regions contribute with different TEPs. At the high magnetic field and low temperature, the TEP has large fluctuations near the Dirac point associated with the disorder in the CVD-graphene. TEP measurements reveal additional characteristics of CVD-graphene, which are difficult to obtain from the measurement of resistance alone.

  3. Chemical vapor deposition of organosilicon composite thin films for porous low-k dielectrics

    E-Print Network [OSTI]

    Ross, April Denise, 1977-

    2005-01-01T23:59:59.000Z

    Pulsed plasma enhanced chemical vapor deposition has produced organosilicon thin films with the potential use as low dielectric constant interconnect materials in microelectronic circuits. Both diethylsilane and ...

  4. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, Kevin C. (4745 Trinity Dr., Los Alamos, NM 87544); Kodas, Toivo T. (5200 Noreen Dr. NE., Albuquerque, NM 87111)

    1994-01-01T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  5. Oxidative chemical vapor deposition of conductive polymers for use in novel photovoltaic device architectures

    E-Print Network [OSTI]

    Howden, Rachel M. (Rachel Mary)

    2013-01-01T23:59:59.000Z

    The conductive polymer poly(3,4-ethylenedioxythiophene), (PEDOT), deposited via oxidative chemical vapor deposition (oCVD) has been investigated for use in organic electronic devices. The oCVD process as well as the ...

  6. Carbon impurities on graphene synthesized by chemical vapor deposition on platinum

    SciTech Connect (OSTI)

    Ping, Jinglei; Fuhrer, Michael S., E-mail: michael.fuhrer@monash.edu [Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111, USA and School of Physics, Monash University, 3800 Victoria (Australia)

    2014-07-28T23:59:59.000Z

    We report nanocrystalline carbon impurities coexisting with graphene synthesized via chemical vapor deposition on platinum. For certain growth conditions, we observe micron-size island-like impurity layers which can be mistaken for second graphene layers in optical microscopy or scanning electron microscopy. The island orientation depends on the crystalline orientation of the Pt, as shown by electron backscatter diffraction, indicating growth of carbon at the platinum surface below graphene. Dark-field transmission electron microscopy indicates that in addition to uniform single-crystal graphene, our sample is decorated with nanocrystalline carbon impurities with a spatially inhomogeneous distribution. The impurity concentration can be reduced significantly by lowering the growth temperature. Raman spectra show a large D peak, however, electrical characterization shows high mobility (?8000?cm{sup 2}/Vs), indicating a limitation for Raman spectroscopy in characterizing the electronic quality of graphene.

  7. Field emission properties of chemical vapor deposited individual graphene

    SciTech Connect (OSTI)

    Zamri Yusop, Mohd [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Department of Materials, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Center for Fostering Young and Innovative Researchers, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Yaakob, Yazid; Takahashi, Chisato; Tanemura, Masaki [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan)

    2014-03-03T23:59:59.000Z

    Here, we report field emission (FE) properties of a chemical vapor deposited individual graphene investigated by in-situ transmission electron microscopy. Free-standing bilayer graphene is mounted on a cathode microprobe and FE processes are investigated varying the vacuum gap of cathode and anode. The threshold field for 10?nA current were found to be 515, 610, and 870?V/?m for vacuum gap of 400, 300, and 200?nm, respectively. It is observed that the structural stability of a high quality bilayer graphene is considerably stable during emission process. By contacting the nanoprobe with graphene and applying a bias voltage, structural deformation and buckling are observed with significant rise in temperature owing to Joule heating effect. The finding can be significant for practical application of graphene related materials in emitter based devices as well as understanding the contact resistance influence and heating effect.

  8. Low Temperature Chemical Vapor Deposition Of Thin Film Magnets

    DOE Patents [OSTI]

    Miller, Joel S. (Salt Lake City, UT); Pokhodnya, Kostyantyn I. (Salt Lake City, UT)

    2003-12-09T23:59:59.000Z

    A thin-film magnet formed from a gas-phase reaction of tetracyanoetheylene (TCNE) OR (TCNQ), 7,7,8,8-tetracyano-P-quinodimethane, and a vanadium-containing compound such as vanadium hexcarbonyl (V(CO).sub.6) and bis(benzene)vanalium (V(C.sub.6 H.sub.6).sub.2) and a process of forming a magnetic thin film upon at least one substrate by chemical vapor deposition (CVD) at a process temperature not exceeding approximately 90.degree. C. and in the absence of a solvent. The magnetic thin film is particularly suitable for being disposed upon rigid or flexible substrates at temperatures in the range of 40.degree. C. and 70.degree. C. The present invention exhibits air-stable characteristics and qualities and is particularly suitable for providing being disposed upon a wide variety of substrates.

  9. Computational Analysis and Optimization of a Chemical Vapor Deposition Reactor with

    E-Print Network [OSTI]

    modifications of reactor configurations and manual control of operating conditions becomes prohibitivelyComputational Analysis and Optimization of a Chemical Vapor Deposition Reactor with Large for the chemical vapor deposition (CVD) of silicon in a horizontal rotating disk reactor. A three

  10. Low temperature chemical vapor deposition of Co thin films from Co2(CO)8

    E-Print Network [OSTI]

    Wang, Gwo-Ching

    Low temperature chemical vapor deposition of Co thin films from Co2(CO)8 D.-X. Yea,*, S. Pimanpanga chemical vapor deposition with a metallorganic Co2(CO)8 precursor. After Ar sputtering of the surface, Co2(CO)8, has been extensively used in cobalt CVD and is attractive, since Co is in its elemental

  11. Lithium phosphorous oxynitride films synthesized by a plasma-assisted directed vapor deposition approach

    E-Print Network [OSTI]

    Wadley, Haydn

    Lithium phosphorous oxynitride films synthesized by a plasma-assisted directed vapor deposition vapor deposition approach has been explored for the synthesis of lithium phosphorous oxynitride Lipon the ionic transport properties of these films. This enabled the synthesis of electrolyte films with lithium

  12. Molecular Orbital Studies of Titanium Nitride Chemical Vapor Deposition: Gas Phase Complex Formation,

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Molecular Orbital Studies of Titanium Nitride Chemical Vapor Deposition: Gas Phase Complex Received June 6, 2000 The chemical vapor deposition (CVD) of titanium nitride can be carried out with TiCl4 Titanium nitride thin films have a variety of proper- ties, such as extreme hardness, high chemical

  13. Molecular Orbital Studies of Titanium Nitride Chemical Vapor Deposition: Imido Dimer Formation and

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Molecular Orbital Studies of Titanium Nitride Chemical Vapor Deposition: Imido Dimer Formation- ization of Ti(NR2)2NH in the chemical vapor deposition (CVD) of titanium nitride films. This study uses lead to the formation of higher oligomers. Introduction Titanium nitride thin films have a number

  14. Tunneling characteristics in chemical vapor deposited graphene hexagonal boron nitride graphene junctions

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Tunneling characteristics in chemical vapor deposited graphene ­ hexagonal boron nitride ­ graphene junctions T. Roy1 , L. Liu2 , S. de la Barrera,3 B. Chakrabarti1,4 , Z. R. Hesabi1 , C. A. Joiner1 Abstract: Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate

  15. Momentum and thermal boundary-layer thickness in a stagnation flow chemical vapor deposition reactor

    E-Print Network [OSTI]

    Dandy, David

    reactor David S. Dandy and Jungheum Yun Department of Chemical Engineering, Colorado State University stagnation flows characteristic of highly convective chemical vapor deposition pedestal reactors. Expressions of diamond via low- pressure chemical vapor deposition, direct current (dc) arcjet reactor systems3­8 have

  16. Properties of chemical vapor infiltration diamond deposited in a diamond powder matrix

    SciTech Connect (OSTI)

    Panitz, J.K.G.; Tallant, D.R.; Hills, C.R.; Staley, D.J.

    1993-12-31T23:59:59.000Z

    Densifying non-mined diamond powder precursors with diamond produced by chemical vapor infiltration (CVI) is an attractive approach for forming thick diamond deposits that avoids many potential manufacturability problems associated with predominantly chemical vapor deposition (CVD) processes. The authors have developed two techniques: electrophoretic deposition and screen printing, to form nonmined diamond powder precursors on substrates. They then densify these precursors in a hot filament assisted reactor. Analysis indicated that a hot filament assisted chemical vapor infiltration process forms intergranular diamond deposits with properties that are to some degree different from predominantly hot-filament-assisted CVD material.

  17. Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective

    SciTech Connect (OSTI)

    Anders, Andre

    2007-02-28T23:59:59.000Z

    Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

  18. Low Temperature Chemical Vapor Deposition of Zirconium Nitride in a Fluidized Bed 

    E-Print Network [OSTI]

    Arrieta, Marie

    2012-10-19T23:59:59.000Z

    The objective of this research was to design, assemble, and demonstrate the initial performance of a fluidized bed chemical vapor deposition (FB-CVD) system capable of producing thin, uniform zirconium nitride (ZrN) coatings (1 to 10 micrometers...

  19. Iron (III) Chloride doping of large-area chemical vapor deposition graphene

    E-Print Network [OSTI]

    Song, Yi, S.M. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Chemical doping is an effective method of reducing the sheet resistance of graphene. This thesis aims to develop an effective method of doping large area Chemical Vapor Deposition (CVD) graphene using Iron (III) Chloride ...

  20. Single- and few-layer graphene by ambient pressure chemical vapor deposition on nickel

    E-Print Network [OSTI]

    Reina Ceeco, Alfonso

    2010-01-01T23:59:59.000Z

    An ambient pressure chemical vapor deposition (APCVD) process is used to fabricate graphene based films consisting of one to several graphene layers across their area. Polycrystalline Ni thin films are used and the graphene ...

  1. Porous GaN nanowires synthesized using thermal chemical vapor deposition

    E-Print Network [OSTI]

    Kim, Bongsoo

    Porous GaN nanowires synthesized using thermal chemical vapor deposition Seung Yong Bae a , Hee Won 2003 Abstract Porous structured GaN nanowires were synthesized with a large scale by chemical vapor to 1 mm. The porous GaN nanowires consist of the wurtzite single crystal grown with the [0 1 1

  2. Solar-induced chemical vapor deposition of diamond-type carbon films

    DOE Patents [OSTI]

    Pitts, J.R.; Tracy, C.E.; King, D.E.; Stanley, J.T.

    1994-09-13T23:59:59.000Z

    An improved chemical vapor deposition method for depositing transparent continuous coatings of sp[sup 3]-bonded diamond-type carbon films, comprises: (a) providing a volatile hydrocarbon gas/H[sub 2] reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and (b) directing a concentrated solar flux of from about 40 to about 60 watts/cm[sup 2] through said reactant mixture to produce substrate temperatures of about 750 C to about 950 C to activate deposition of the film on said substrate. 11 figs.

  3. Fabrication of nanostructure by physical vapor deposition with glancing angle deposition technique and its applications

    SciTech Connect (OSTI)

    Horprathum, M., E-mail: mati.horprathum@nectec.or.th; Eiamchai, P., E-mail: mati.horprathum@nectec.or.th; Patthanasettakul, V.; Limwichean, S.; Nuntawong, N.; Chindaudom, P. [Optical Thin-Film Laboratory National Electronics and Computer Technology Center, Pathumthani, 12120 (Thailand); Kaewkhao, J. [Center of Excellence in Glass Technology and Materials Science (CEGM), Nakhon Pathom Rajabhat University, Nakhon Pathom 73000 (Thailand); Chananonnawathorn, C. [Department of Physics, Faculty of Science and Technology, Thammasat University, Pathumthani, 12121 (Thailand)

    2014-09-25T23:59:59.000Z

    A nanostructural thin film is one of the highly exploiting research areas particularly in applications in sensor, photocatalytic, and solar-cell technologies. In the past two decades, the integration of glancing-angle deposition (GLAD) technique to physical vapor deposition (PVD) process has gained significant attention for well-controlled multidimensional nanomorphologies because of fast, simple, cost-effective, and mass-production capability. The performance and functional properties of the coated thin films generally depend upon their nanostructural compositions, i.e., large aspect ratio, controllable porosity, and shape. Such structural platforms make the fabricated thin films very practical for several realistic applications. We therefore present morphological and nanostructural properties of various deposited materials, which included metals, i.e., silver (Ag), and oxide compounds, i.e., tungsten oxide (WO{sub 3}), titanium dioxide (TiO{sub 2}), and indium tin oxide (ITO). Different PVD techniques based on DC magnetron sputtering and electron-beam evaporation, both with the integrated GLAD component, were discussed. We further explore engineered nanostructures which enable controls of optical, electrical, and mechanical properties. These improvements led to several practical applications in surface-enhanced Raman, smart windows, gas sensors, self-cleaning materials and transparent conductive oxides (TCO)

  4. On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.

    SciTech Connect (OSTI)

    Allendorf, Mark D.; Sopko, J.F. (PPF Industries, Pittsburgh, PA); Houf, William G.; Chae, Yong Kee; McDaniel, Anthony H.; Li, M. (PPF Industries, Pittsburgh, PA); McCamy, J.W. (PPF Industries, Pittsburgh, PA)

    2006-11-01T23:59:59.000Z

    Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accurate data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions are reached concerning the factors affecting the growth rate in on-line APCVD reactors. In addition, a substantial body of data was generated that can be used to model many different industrial tin oxide coating processes. These data include the most extensive compilation of thermochemistry for gas-phase tin-containing species as well as kinetic expressions describing tin oxide growth rates over a wide range of temperatures, pressures, and reactant concentrations.

  5. Continuous ultra-thin MoS{sub 2} films grown by low-temperature physical vapor deposition

    SciTech Connect (OSTI)

    Muratore, C. [Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Hu, J. J.; Bultman, J. E.; Jespersen, M. L. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); University of Dayton Research Institute, Dayton, Ohio 45469 (United States); Wang, B.; Haque, M. A. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, College Park, Pennsylvania 16802 (United States); Shamberger, P. J.; McConney, M. E.; Naguy, R. D.; Voevodin, A. A. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)

    2014-06-30T23:59:59.000Z

    Uniform growth of pristine two dimensional (2D) materials over large areas at lower temperatures without sacrifice of their unique physical properties is a critical pre-requisite for seamless integration of next-generation van der Waals heterostructures into functional devices. This Letter describes a vapor phase growth technique for precisely controlled synthesis of continuous, uniform molecular layers of MoS{sub 2} on silicon dioxide and highly oriented pyrolitic graphite substrates of over several square centimeters at 350?°C. Synthesis of few-layer MoS{sub 2} in this ultra-high vacuum physical vapor deposition process yields materials with key optical and electronic properties identical to exfoliated layers. The films are composed of nano-scale domains with strong chemical binding between domain boundaries, allowing lift-off from the substrate and electronic transport measurements from contacts with separation on the order of centimeters.

  6. Development of a spatially controllable chemical vapor deposition reactor with combinatorial processing capabilities

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Development of a spatially controllable chemical vapor deposition reactor with combinatorial these limitations, a novel CVD reactor system has been developed that can explicitly control the spatial profile flexibility, we introduced a new CVD reactor concept that enables control of film deposition characteristics

  7. Chemical vapor deposition of W-Si-N and W-B-N

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Roherty-Osmun, Elizabeth Lynn (Albuquerque, NM); Smith, Paul M. (Albuquerque, NM); Custer, Jonathan S. (Albuquerque, NM); Jones, Ronald V. (Albuquerque, NM); Nicolet, Marc-A. (Pasadena, CA); Madar, Roland (Eybens, FR); Bernard, Claude (Brie et Angonnes, FR)

    1999-01-01T23:59:59.000Z

    A method of depositing a ternary, refractory based thin film on a substrate by chemical vapor deposition employing precursor sources of tungsten comprising WF.sub.6, either silicon or boron, and nitrogen. The result is a W--Si--N or W--B--N thin film useful for diffusion barrier and micromachining applications.

  8. Chemical vapor deposition of W-Si-N and W-B-N

    DOE Patents [OSTI]

    Fleming, J.G.; Roherty-Osmun, E.L.; Smith, P.M.; Custer, J.S.; Jones, R.V.; Nicolet, M.; Madar, R.; Bernard, C.

    1999-06-29T23:59:59.000Z

    A method of depositing a ternary, refractory based thin film on a substrate by chemical vapor deposition employing precursor sources of tungsten comprising WF[sub 6], either silicon or boron, and nitrogen. The result is a W-Si-N or W-B-N thin film useful for diffusion barrier and micromachining applications. 10 figs.

  9. Multiplexed mass spectrometry for real-time sensing in a spatially programmable chemical vapor deposition reactor

    E-Print Network [OSTI]

    Rubloff, Gary W.

    deposition reactor Yuhong Cai, Laurent Henn-Lecordier, and Gary W. Rubloffa Department of Materials Science locations in a spatially programmable chemical vapor deposition SP-CVD reactor prototype, where such chemical sensing is essential to achieve the benefits of a new paradigm for reactor design. The spatially

  10. Droplet destabilization during Bi catalyzed vapor-liquuid-solid growth of GaAs

    SciTech Connect (OSTI)

    DeJarld, M., E-mail: mdejarld@umich.edu; Nothern, D.; Millunchick, J. M. [Department of Materials Science and Engineering, University of Michigan 2300 Hayward Street, Ann Arbor, Michigan 48105 (United States)

    2014-03-21T23:59:59.000Z

    GaAs nanodiscs are grown in a molecular beam epitaxy chamber via the vapor-liquid-solid mechanism with liquid Bi as the catalyst. Each nanostructure consists of a series of increasingly larger overlapping discs. The structure forms during deposition due to the fact that the catalyst grows until reaching a critical size whereupon it destabilizes, dropping off the disc onto the substrate, where it catalyzes the growth of a new disc of larger radius. It is shown that critical size is limited by the sidewall wetting with a contact angle significantly smaller than the Gibb's criterion.

  11. Formation of amorphous metal alloys by chemical vapor deposition

    DOE Patents [OSTI]

    Mullendore, A.W.

    1988-03-18T23:59:59.000Z

    Amorphous alloys are deposited by a process of thermal dissociation of mixtures of organometallic compounds and metalloid hydrides,e.g., transition metal carbonyl, such as nickel carbonyl and diborane. Various sizes and shapes of deposits can be achieved, including near-net-shape free standing articles, multilayer deposits, and the like. Manipulation or absence of a magnetic field affects the nature and the structure of the deposit. 1 fig.

  12. Formation of amorphous metal alloys by chemical vapor deposition

    DOE Patents [OSTI]

    Mullendore, Arthur W. (Sandia Park, NM)

    1990-01-01T23:59:59.000Z

    Amorphous alloys are deposited by a process of thermal dissociation of mixtures or organometallic compounds and metalloid hydrides, e.g., transition metal carbonyl such as nickel carbonyl, and diborane. Various sizes and shapes of deposits can be achieved, including near-net-shape free standing articles, multilayer deposits, and the like. Manipulation or absence of a magnetic field affects the nature and the structure of the deposit.

  13. Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

    DOE Patents [OSTI]

    Lackey, Jr., Walter J. (Oak Ridge, TN); Caputo, Anthony J. (Knoxville, TN)

    1986-01-01T23:59:59.000Z

    A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

  14. Improved process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

    DOE Patents [OSTI]

    Lackey, W.J. Jr.; Caputo, A.J.

    1984-09-07T23:59:59.000Z

    A specially designed apparatus provides a steep thermal gradient across the thickness of fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

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

    SciTech Connect (OSTI)

    Robbins, Joshua; Seman, Michael

    2005-09-20T23:59:59.000Z

    Electrochromic windows have been identified by the Basic energy Sciences Advisory committee as an important technology for the reduction of energy spent on heating and cooling in residential and commercial buildings. Electrochromic devices have the ability to reversibly alter their optical properties in response to a small electric field. By blocking ultraviolet and infrared radiation, while modulating the incoming visible radiation, electrochromics could reduce energy consumption by several Quads per year. This amounts to several percent of the total annual national energy expenditures. The purpose of this project was to demonstrate proof of concept for using plasma-enhanced chemical vapor deposition (PECVD) for depositing all five layers necessary for full electrochromic devices, as an alternative to sputtering techniques. The overall goal is to produce electrochromic devices on flexible polymer substrates using PECVD to significantly reduce the cost of the final product. We have successfully deposited all of the films necessary for a complete electrochromic devices using PECVD. The electrochromic layer, WO3, displayed excellent change in visible transmission with good switching times. The storage layer, V2O5, exhibited a high storage capacity and good clear state transmission. The electrolyte, Ta2O5, was shown to functional with good electrical resistivity to go along with the ability to transfer Li ions. There were issues with leakage over larger areas, which can be address with further process development. We developed a process to deposit ZnO:Ga with a sheet resistance of < 50 W/sq. with > 90% transmission. Although we were not able to deposit on polymers due to the temperatures required in combination with the inverted position of our substrates. Two types of full devices were produced. Devices with Ta2O5 were shown to be functional using small aluminum dots as the top contact. The polymer electrolyte devices were shown to have a clear state transmission of 69% and a darkened state transmission 11%. These un-optimized devices compared well with commercially available products, which have a stated clear transmission of 59% and dark transmission of 4%. The PECVD oxides have displayed advantages over films produced by sputtering. The first advantage is that deposition rates were significantly higher than typical sputtering rates. Rates of 100 nm/min were achieved for WO3, and rates of 50 nm/min produced quality V2O5 and Ta2O5 films. Faster rates will produce a significant reduction in cost due to higher throughput. Another advantage was that films were less dense than those produced by sputtering as reported in the literature. This leads to high diffusion coefficients and fast switching times. Also less dense films have been shown to produce larger contrast ratios in WO3 and larger storage capacity in V2O5. From the data collected in this category 1 project we have shown that PECVD is feasible and beneficial for the deposition of working layers for electrochromic devices. These results and the lessons learned can be applied toward deposition on polymers and equipment scale-up in future work.

  16. Ultra-narrow ferromagnetic resonance in organic-based thin films grown via low temperature chemical vapor deposition

    SciTech Connect (OSTI)

    Yu, H.; Harberts, M.; Adur, R.; Hammel, P. Chris; Johnston-Halperin, E., E-mail: ejh@physics.osu.edu, E-mail: epstein@physics.osu.edu [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1117 (United States); Lu, Y. [Department of Chemistry, The Ohio State University, Columbus, Ohio 43210-1173 (United States); Epstein, A. J., E-mail: ejh@physics.osu.edu, E-mail: epstein@physics.osu.edu [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1117 (United States); Department of Chemistry, The Ohio State University, Columbus, Ohio 43210-1173 (United States)

    2014-07-07T23:59:59.000Z

    We present the growth of thin films of the organic-based ferrimagnetic semiconductor V[TCNE]{sub x} (x???2, TCNE: tetracyanoethylene) via chemical vapor deposition. Under optimized growth conditions, we observe a significant increase in magnetic homogeneity, as evidenced by a Curie temperature above 600?K and sharp magnetization switching. Further, ferromagnetic resonance studies reveal a single resonance with full width at half maximum linewidth of 1.4?G, comparable to the narrowest lines measured in inorganic magnetic materials and in contrast to previous studies that showed multiple resonance features. These characteristics are promising for the development of high frequency electronic devices that take advantage of the unique properties of this organic-based material, such as the potential for low cost synthesis combined with low temperature and conformal deposition on a wide variety of substrates.

  17. Deposition of silicon carbide films using a high vacuum metalorganic chemical vapor deposition method with a single source precursor

    E-Print Network [OSTI]

    Boo, Jin-Hyo

    , high temperature, and high radiation environments. Conventional silicon carbide chemical vapor deposition CVD processes generally utilized multiple precursors such as silane and hydrocarbons, and required temperature alternatives to the conventional SiC CVD methods must be considered. To do this, a relatively

  18. arc vapor deposition: Topics by E-print Network

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

    Materials Science Websites Summary: applied to the deposition of thermal barrier coatings onto an airfoil substrate using a gas jet assisted) principles have become...

  19. Research on fundamental aspects of inorganic vapor and particle deposition in coal-fired systems

    SciTech Connect (OSTI)

    Rosner, D.E.

    1992-06-01T23:59:59.000Z

    Parallel research studies are underway on the following interrelated and fundamental subjects; Geometrical Approach to Determining the Sticking Probability of Particles Impacting on Convex Solid Surfaces; Correlations for High Schmidt Number Particle Deposition From Dilute Flowing Rational Engineering Suspensions; Average Capture Probability of Arriving Particles Which Are Distributed With ResPect to ImPact VelocitY and Incidence Angle (Relative to Deposit Substrate); Experimental and Theoretical Studies of Vapor Infiltration of Non-isothermal Granular Deposits; Effective Area/Volume of Populations of 'MicroPorous' Aerosol Particles (Compact and 'Fractal' Quasispherical Aggregates); Effects of Radiative Heat Transfer on the Coagulation Rates of Combustion-Generated Particles; Structure-Sensitivity of Total Mass Deposition Rates from Combustion Product Streams containing Coagulation-Aged Populations of Aggregated Primary Particles; and Na[sub 2]SO[sub 4] Chemical Vapor Deposition From Chlorine-containing Coal-Derived Gases.

  20. Analysis of gallium arsenide deposition in a horizontal chemical vapor deposition reactor using massively parallel computations

    SciTech Connect (OSTI)

    Salinger, A.G.; Shadid, J.N.; Hutchinson, S.A. [and others

    1998-01-01T23:59:59.000Z

    A numerical analysis of the deposition of gallium from trimethylgallium (TMG) and arsine in a horizontal CVD reactor with tilted susceptor and a three inch diameter rotating substrate is performed. The three-dimensional model includes complete coupling between fluid mechanics, heat transfer, and species transport, and is solved using an unstructured finite element discretization on a massively parallel computer. The effects of three operating parameters (the disk rotation rate, inlet TMG fraction, and inlet velocity) and two design parameters (the tilt angle of the reactor base and the reactor width) on the growth rate and uniformity are presented. The nonlinear dependence of the growth rate uniformity on the key operating parameters is discussed in detail. Efficient and robust algorithms for massively parallel reacting flow simulations, as incorporated into our analysis code MPSalsa, make detailed analysis of this complicated system feasible.

  1. Nitrogen doping of chemical vapor deposition grown graphene on 4H-SiC (0001)

    SciTech Connect (OSTI)

    Urban, J. M.; Binder, J.; Wysmo?ek, A. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); D?browski, P.; Strupi?ski, W. [Institute of Electronic Materials Technology, ul. Wólczy?ska 133, 01-919 Warsaw (Poland); Kopciuszy?ski, M.; Ja?ochowski, M. [Institute of Physics, Maria Curie-Sk?odowska University, pl. M. Curie-Sk?odowskiej 1, 20-031 Lublin (Poland); Klusek, Z. [Faculty of Physics and Applied Informatics, University of ?ód?, ul. Pomorska 149/153, 90-236 ?ód? (Poland); Baranowski, J. M. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wólczy?ska 133, 01-919 Warsaw (Poland)

    2014-06-21T23:59:59.000Z

    We present optical, electrical, and structural properties of nitrogen-doped graphene grown on the Si face of 4H-SiC (0001) by chemical vapor deposition method using propane as the carbon precursor and N{sub 2} as the nitrogen source. The incorporation of nitrogen in the carbon lattice was confirmed by X-ray photoelectron spectroscopy. Angle-resolved photoemission spectroscopy shows carrier behavior characteristic for massless Dirac fermions and confirms the presence of a graphene monolayer in the investigated nitrogen-doped samples. The structural and electronic properties of the material were investigated by Raman spectroscopy. A systematical analysis of the graphene Raman spectra, including D, G, and 2D bands, was performed. In the case of nitrogen-doped samples, an electron concentration on the order of 5–10 × 10{sup 12}?cm{sup ?2} was estimated based upon Raman and Hall effect measurements and no clear dependence of the carrier concentration on nitrogen concentration used during growth was observed. This high electron concentration can be interpreted as both due to the presence of nitrogen in graphitic-like positions of the graphene lattice as well as to the interaction with the substrate. A greater intensity of the Raman D band and increased inhomogeneity, as well as decreased electron mobility, observed for nitrogen-doped samples, indicate the formation of defects and a modification of the growth process induced by nitrogen doping.

  2. Solar Energy Materials & Solar Cells 91 (2007) 924930 Plasma-enhanced chemical vapor deposition of zinc oxide at

    E-Print Network [OSTI]

    Hicks, Robert F.

    2007-01-01T23:59:59.000Z

    Solar Energy Materials & Solar Cells 91 (2007) 924­930 Plasma-enhanced chemical vapor deposition (CIGS) or plastic substrates [1,2,8]. In this paper, we report on the deposition of aluminum- doped zinc

  3. Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape

    SciTech Connect (OSTI)

    Cunha, T. H. R.; Ek-Weis, J.; Lacerda, R. G.; Ferlauto, A. S., E-mail: ferlauto@fisica.ufmg.br [Department of Physics, Federal University of Minas Gerais, Belo Horizonte 31270-901 (Brazil)

    2014-08-18T23:59:59.000Z

    The initial stages of graphene chemical vapor deposition at very low pressures (<10{sup ?5?}Torr) were investigated. The growth of large graphene domains (?up to 100??m) at very high rates (up to 3??m{sup 2} s{sup ?1}) has been achieved in a cold-wall reactor using a liquid carbon precursor. For high temperature growth (>900?°C), graphene grain shape and symmetry were found to depend on the underlying symmetry of the Cu crystal, whereas for lower temperatures (<900?°C), mostly rounded grains are observed. The temperature dependence of graphene nucleation density was determined, displaying two thermally activated regimes, with activation energy values of 6?±?1?eV for temperatures ranging from 900?°C to 960?°C and 9?±?1?eV for temperatures above 960?°C. The comparison of such dependence with the temperature dependence of Cu surface self-diffusion suggests that graphene growth at high temperatures and low pressures is strongly influenced by copper surface rearrangement. We propose a model that incorporates Cu surface self-diffusion as an essential process to explain the orientation correlation between graphene and Cu crystals, and which can clarify the difference generally observed between graphene domain shapes in atmospheric-pressure and low-pressure chemical vapor deposition.

  4. Ceramic-metallic coatings by electron beam physical vapor deposition (EB-PVD) process

    SciTech Connect (OSTI)

    Wolfe, D.E.; Singh, J. [Pennsylvania State Univ., State College, PA (United States)

    1995-12-31T23:59:59.000Z

    Electron Beam Physical Vapor Deposition (EB-PVD) process is considered to be a technology that has overcome some of the difficulties or problems associated with the chemical vapor deposition (CVD), physical vapor deposition (PVD) and metal spray processes. The EB-PVD process offers many desirable characteristics such as relatively high deposition rates (up to 100-150 {mu}m/minute with an evaporation rate {approx}10-15 Kg/hour,) dense coatings, precise compositional control, columnar and poly-crystalline microstructure, low contamination, and high thermal efficiency. Various metallic and ceramic coatings (oxides, carbides, nitrides) can be deposited at relatively low temperatures. Even elements with low vapor pressure such as molybdenum, tungsten, and carbon are readily evaporated by this process. In addition, EB-PVD is capable of producing multi-layered laminated metallic/ceramic coatings on large components by changing the EB-PVD processing conditions such as ingot composition, part manipulation, and electron beam energy. Attachment of an ion assisted beam source to the EB-PVD offers additional benefits such as dense coatings with improved adhesion. In addition, textured coatings can be obtained that are desirable in many applications such as cutting tools. This laboratory has started a new thrust in the coating area by the EB-PVD process. The microstructure of thermal barrier ceramic coatings (i.e., yttria stabilized zirconia) developed by the EB-PVD process will be presented.

  5. atomic vapor deposited: Topics by E-print Network

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

    deposition onto micro- and nanopowders14 and coating of nanoparticle films15 as well as aerogel coating of porous materials that exhibit ultrahigh-aspect ratios.12,13 To date,...

  6. SPATIALLY ORGANIZED PARYLENE NANOWIRES FABRICATED BY OBLIQUE ANGLE VAPOR DEPOSITION

    E-Print Network [OSTI]

    Demirel, Melik C.

    surfaces by functionalization through two methods: (i) electroless method of creating a porous Nickel 50-80 nm thin nickel film can be obtained by electroless deposition on the pary

  7. Study of anisotropy of spin cast and vapor deposited polyimide films using internal reflection techniques

    SciTech Connect (OSTI)

    Liberman, V.

    1996-11-01T23:59:59.000Z

    We have compared anisotropy of spin cast and vapor deposited polyimide (VDP) films, using internal reflection infrared spectroscopy. The films were deposited directly on the internal reflection element. We find that spin cast films are more anisotropic than their VDP counterparts, with the polyimide chains tending to align parallel to the substrate. Both films are found to contain more and less ordered regions. Within the ordered regions, the plane of the phenyl ring tends to align parallel to the substrate.

  8. Field emission properties of phosphorus doped microwave plasma chemical vapor deposition diamond films by ion implantation

    E-Print Network [OSTI]

    Lee, Jong Duk

    2002; published 5 February 2003 Phosphorus doped polycrystalline diamond films were grown using ion the electrical char- acteristics of diamond FEAs to lower the operating voltage. Polycrystalline diamond hasField emission properties of phosphorus doped microwave plasma chemical vapor deposition diamond

  9. Chemical Vapor Deposition-Derived Graphene with Electrical Performance of Exfoliated Graphene

    E-Print Network [OSTI]

    Hone, James

    Chemical Vapor Deposition-Derived Graphene with Electrical Performance of Exfoliated Graphene a scalable method to produce large-area graphene, CVD-grown graphene has heretofore exhibited inferior of CVD-grown graphene in which two important sources of disorder, namely grain boundaries and processing

  10. Synthesis of high-quality monolayer and bilayer graphene on copper using chemical vapor deposition

    E-Print Network [OSTI]

    exfoliation of graphite [1], sublimation of epitaxial SiC [4], and catalyst-assisted chemical vapor deposition (CVD) [5­9]. However, mechanical exfoliation of graphite can only supply small-size graphene (see Fig than that of graphene obtained via exfoli- ation of graphite as summarized in Fig. 1. While many

  11. Atmospheric pressure chemical vapor deposition of TiN from tetrakis(dimethylamido)titanium and ammonia

    E-Print Network [OSTI]

    of titanium in a nitrogen atmosphere forms TiN with only a slight dependence on substrate temperatureAtmospheric pressure chemical vapor deposition of TiN from tetrakis(dimethylamido)titanium, Massachusetts 02138 (Received 15 December 1994; accepted 28 October 1995) Near stoichiometric titanium nitride

  12. Z .Thin Solid Films 392 2001 231 235 Atmospheric pressure chemical vapor deposition of

    E-Print Network [OSTI]

    of electrochromic tungsten oxide films Roy G. Gordona,U , Sean Barryb , Jeffrey T. Bartona , Randy N.R. Broomhall oxide, WO , is a coloring layer commonly used in electrochromic windows and displays. Successful: Chemical vapor deposition; Tungsten; Oxides; Electrochromism 1. Introduction Tungsten oxide is a key

  13. Vapor phase deposition of oligo,,phenylene ethynylene... molecules for use in molecular electronic devices

    E-Print Network [OSTI]

    Bean, John C.

    , many groups have made headway fab- ricating molecular electronic test devices.1­18 These devices exceptions,22,23 the field of mo- lecular electronics is plagued by problems including a lack of deviceVapor phase deposition of oligo,,phenylene ethynylene... molecules for use in molecular electronic

  14. Initiated chemical vapor deposition of fluoropolymer coatings for the surface modification of complex geometries

    E-Print Network [OSTI]

    Gupta, Malancha, 1980-

    2007-01-01T23:59:59.000Z

    Initiated chemical vapor deposition (iCVD) is a one-step, soventless process that can be used to produce polymeric thin films. The iCVD technique has been used to polymerize a wide variety of vinyl monomers such as glycidyl ...

  15. Molecular orbital studies of titanium nitride chemical vapor deposition: gas phase b-elimination

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Molecular orbital studies of titanium nitride chemical vapor deposition: gas phase b) of titanium nitride can be carried out using TiNR24 and NH3 (R Me or Et). Imido compounds are thought. Ó 2001 Pub- lished by Elsevier Science B.V. 1. Introduction It is well known that titanium nitride

  16. Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films on sapphire

    E-Print Network [OSTI]

    Boyer, Edmond

    Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films Cedex 9, France (Dated: 15 March 2011) Uniform single layer graphene was grown on single-crystal Ir. These graphene layers have a single crystallographic orientation and a very low density of defects, as shown

  17. Direct chemical vapor deposition of graphene on dielectric surfaces

    DOE Patents [OSTI]

    Zhang, Yuegang; Ismach, Ariel

    2014-04-29T23:59:59.000Z

    A substrate is provided that has a metallic layer on a substrate surface of a substrate. A film made of a two dimensional (2-D) material, such as graphene, is deposited on a metallic surface of the metallic layer. The metallic layer is dewet and/or removed to provide the film on the substrate surface.

  18. On the possibility to grow zinc oxide-based transparent conducting oxide films by hot-wire chemical vapor deposition

    SciTech Connect (OSTI)

    Abrutis, Adulfas, E-mail: adulfas.abrutis@chf.vu.lt; Silimavicus, Laimis; Kubilius, Virgaudas; Murauskas, Tomas; Saltyte, Zita; Kuprenaite, Sabina; Plausinaitiene, Valentina [Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania)

    2014-03-15T23:59:59.000Z

    Hot-wire chemical vapor deposition (HW-CVD) was applied to grow zinc oxide (ZnO)-based transparent conducting oxide (TCO) films. Indium (In)-doped ZnO films were deposited using a cold wall pulsed liquid injection CVD system with three nichrome wires installed at a distance of 2?cm from the substrate holder. The wires were heated by an AC current in the range of 0–10 A. Zn and In 2,2,6,6-tetramethyl-3,5-heptanedionates dissolved in 1,2-dimethoxyethane were used as precursors. The hot wires had a marked effect on the growth rates of ZnO, In-doped ZnO, and In{sub 2}O{sub 3} films; at a current of 6–10 A, growth rates were increased by a factor of ?10–20 compared with those of traditional CVD at the same substrate temperature (400?°C). In-doped ZnO films with thickness of ?150?nm deposited on sapphire-R grown at a wire current of 9?A exhibited a resistivity of ?2?×?10{sup ?3} ?cm and transparency of >90% in the visible spectral range. These initial results reveal the potential of HW-CVD for the growth of TCOs.

  19. Conjugate heat transfer and particle transport in outside vapor deposition process

    SciTech Connect (OSTI)

    Choi, M.; Song, Y.; Kang, S.H. [Seoul National Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering

    1995-07-01T23:59:59.000Z

    A numerical study of conjugate heat transfer and particle transport has been carried out for the outside vapor deposition process. A buoyant jet flow impinging on a two-layered cylinder has been analyzed including heat conduction occurring through the two-layered cylinder, which consists of the original target rod and the deposited porous layers. Temperature and flow fields have been obtained by an iterative method, and thermophoretic particle deposition has been studied. Of particular interest are the effects of the thickness of deposited layers, the torch speed, the rotation speed of the cylinder, and the distance between the torch and the cylinder on the heat transfer and particle deposition. Effects of variable properties and tube rotation are also included.

  20. Validating optical emission spectroscopy as a diagnostic of microwave activated CH4/Ar/H2 plasmas used for diamond chemical vapor deposition

    E-Print Network [OSTI]

    Bristol, University of

    chemical vapor deposition of polycrystalline diamond. Several tracer species are monitored in order to gain used for diamond chemical vapor deposition Jie Ma,1 Michael N. R. Ashfold,1,a and Yuri A. Mankelevich2 spectroscopic methods used to diagnose microwave MW plasmas used for diamond chemical vapor deposition CVD . Zhu

  1. Pore evolution during high pressure atomic vapor deposition D. D. Hass Y. Y. Yang H. N. G. Wadley

    E-Print Network [OSTI]

    Wadley, Haydn

    The development of physical vapor deposition systems that employ inert gas jets to entrain and deposit atomic conditions can contain a higher volume fraction of porosity and a different pore morphology to coatings created by conventional, low pressure (\\10-4 Pa) deposition processes. A recent direct simulation Monte

  2. Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

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

    Demaurex, Bénédicte; Bartlome, Richard; Seif, Johannes P.; Geissbühler, Jonas; Alexander, Duncan T.; Jeangros, Quentin; Ballif, Christophe; De Wolf, Stefaan

    2014-08-07T23:59:59.000Z

    Low-temperature (?200?°C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-enhanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems not only frommore »the growth conditions but also from unintentional contamination of the reactor. Based on our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.« less

  3. Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

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

    Demaurex, Bénédicte; Bartlome, Richard; Seif, Johannes P.; Geissbühler, Jonas; Alexander, Duncan T.; Jeangros, Quentin; Ballif, Christophe; De Wolf, Stefaan

    2014-08-07T23:59:59.000Z

    Low-temperature (?200?°C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-enhanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems not only from the growth conditions but also from unintentional contamination of the reactor. Based on our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.

  4. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, K.C.; Kodas, T.T.

    1994-01-11T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate.

  5. Development of Nb{sub 3}Sn Cavity Vapor Diffusion Deposition System

    SciTech Connect (OSTI)

    Eremeev, Grigory V.; Macha, Kurt M.; Clemens, William A.; Park, HyeKyoung; Williams, R. Scott

    2014-02-01T23:59:59.000Z

    Nb{sub 3}Sn is a BCS superconductors with the superconducting critical temperature higher than that of niobium, so theoretically it surpasses the limitations of niobium in RF fields. The feasibility of technology has been demonstrated at 1.5 GHz with Nb{sub 3}Sn vapor deposition technique at Wuppertal University. The benefit at these frequencies is more pronounced at 4.2 K, where Nb{sub 3}Sn coated cavities show RF resistances an order of magnitude lower than that of niobium. At Jefferson Lab we started the development of Nb{sub 3}Sn vapor diffusion deposition system within an R\\&D development program towards compact light sources. Here we present the current progress of the system development.

  6. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect (OSTI)

    Rainer Wallny

    2012-10-15T23:59:59.000Z

    Diamond was studied as a possible radiation hard technology for use in future high radiation environments. With the commissioning of the LHC expected in 2010, and the LHC upgrades expected in 2015, all LHC experiments are planning for detector upgrades which require radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is installed and operational in all LHC experiments. As a result, this material is now being discussed as an alternative sensor material for tracking very close to the interaction region of the super-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications.

  7. Low-temperature germanium ultra-high vacuum chemical vapor deposition for back-end photonic integration

    E-Print Network [OSTI]

    Kimerling, Lionel C.

    Polycrystalline germanium (poly-Ge) grown on amorphous Si (a-Si) by ultra-high vacuum chemical vapor deposition (UHVCVD) over oxide barriers at low temperatures (Tles450degC) exhibits a larger grain size and lower defect ...

  8. Red emission from Eu-doped GaN luminescent films grown by metalorganic chemical vapor deposition

    E-Print Network [OSTI]

    Steckl, Andrew J.

    chemical vapor deposition on GaN/Al2O3 substrates. Trimethylgallium TMGa , ammonia (NH3), and europium 2 europium doping was performed utilizing a europium beta-diketonate, eu- ropium 2,2,4,4-tetramethyl-3

  9. Flux and energy analysis of species in hollow cathode magnetron ionized physical vapor deposition of copper

    SciTech Connect (OSTI)

    Wu, L.; Ko, E.; Dulkin, A.; Park, K. J.; Fields, S.; Leeser, K. [Novellus Systems, Inc., 4000 North 1st St., San Jose, California 95134 (United States); Meng, L.; Ruzic, D. N. [Center for Plasma-Material Interactions, University of Illinois at Urbana-Champaign, 201 South Goodwin, Urbana, Illinois 61801 (United States)

    2010-12-15T23:59:59.000Z

    To meet the stringent requirements of interconnect metallization for sub-32 nm technologies, an unprecedented level of flux and energy control of film forming species has become necessary to further advance ionized physical vapor deposition technology. Such technology development mandates improvements in methods to quantify the metal ion fraction, the gas/metal ion ratio, and the associated ion energies in the total ion flux to the substrate. In this work, a novel method combining planar Langmuir probes, quartz crystal microbalance (QCM), and gridded energy analyzer (GEA) custom instrumentation is developed to estimate the plasma density and temperature as well as to measure the metal ion fraction and ion energy. The measurements were conducted in a Novellus Systems, Inc. Hollow Cathode Magnetron (HCM{sup TM}) physical vapor deposition source used for deposition of Cu seed layer for 65-130 nm technology nodes. The gridded energy analyzer was employed to measure ion flux and ion energy, which was compared to the collocated planar Langmuir probe data. The total ion-to-metal neutral ratio was determined by the QCM combined with GEA. The data collection technique and the corresponding analysis are discussed. The effect of concurrent resputtering during the deposition process on film thickness profile is also discussed.

  10. Plasma-enhanced chemical vapor deposition of graphene on copper substrates

    SciTech Connect (OSTI)

    Woehrl, Nicolas, E-mail: nicolas.woehrl@uni-due.de; Schulz, Stephan [Faculty of Chemistry and CENIDE, University Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)] [Faculty of Chemistry and CENIDE, University Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Ochedowski, Oliver; Gottlieb, Steven [Faculty of Physics and CENIDE, University Duisburg Essen, Lotharstraße 1, 47057 Duisburg (Germany)] [Faculty of Physics and CENIDE, University Duisburg Essen, Lotharstraße 1, 47057 Duisburg (Germany); Shibasaki, Kosuke [Institute of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)] [Institute of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)

    2014-04-15T23:59:59.000Z

    A plasma enhanced vapor deposition process is used to synthesize graphene from a hydrogen/methane gas mixture on copper samples. The graphene samples were transferred onto SiO{sub 2} substrates and characterized by Raman spectroscopic mapping and atomic force microscope topographical mapping. Analysis of the Raman bands shows that the deposited graphene is clearly SLG and that the sheets are deposited on large areas of several mm{sup 2}. The defect density in the graphene sheets is calculated using Raman measurements and the influence of the process pressure on the defect density is measured. Furthermore the origin of these defects is discussed with respect to the process parameters and hence the plasma environment.

  11. Graphene growth with giant domains using chemical vapor deposition

    E-Print Network [OSTI]

    Yong, Virginia; Hahn, H. Thomas

    2011-01-01T23:59:59.000Z

    N. Martensson, Controlling graphene corrugation on lattice-in patterned epitaxial graphene, Science, 2006, 312(5777), 92009, 4(6), 17 A. K. Geim, Graphene: Status and Prospects,

  12. Chemical vapor deposition techniques and related methods for manufacturing microminiature thermionic converters

    DOE Patents [OSTI]

    King, Donald B. (Albuquerque, NM); Sadwick, Laurence P. (Salt Lake City, UT); Wernsman, Bernard R. (Clairton, PA)

    2002-06-25T23:59:59.000Z

    Methods of manufacturing microminiature thermionic converters (MTCs) having high energy-conversion efficiencies and variable operating temperatures using MEMS manufacturing techniques including chemical vapor deposition. The MTCs made using the methods of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. The MTCs also exhibit maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

  13. Tunneling characteristics in chemical vapor deposited graphene–hexagonal boron nitride–graphene junctions

    SciTech Connect (OSTI)

    Roy, T.; Hesabi, Z. R.; Joiner, C. A.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Liu, L.; Gu, G. [Department of Electrical Engineering and Computer Science, University of Tennessee, 1520 Middle Drive, Knoxville, Tennessee 37996 (United States); Barrera, S. de la; Feenstra, R. M. [Department of Physics, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States)

    2014-03-24T23:59:59.000Z

    Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphene–hexagonal boron nitride–graphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphene–hexagonal boron nitride–graphene devices. Density-of-states features are observed in the tunneling characteristics of the devices, although without large resonant peaks that would arise from lateral momentum conservation. The lack of distinct resonant behavior is attributed to disorder in the devices, and a possible source of the disorder is discussed.

  14. Thermal conductivity of ultra-thin chemical vapor deposited hexagonal boron nitride films

    SciTech Connect (OSTI)

    Alam, M. T.; Haque, M. A., E-mail: mah37@psu.edu [Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Bresnehan, M. S.; Robinson, J. A. [Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA and The Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA and The Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-01-06T23:59:59.000Z

    Thermal conductivity of freestanding 10?nm and 20?nm thick chemical vapor deposited hexagonal boron nitride films was measured using both steady state and transient techniques. The measured value for both thicknesses, about 100?±?10?W m{sup ?1} K{sup ?1}, is lower than the bulk basal plane value (390?W m{sup ?1} K{sup ?1}) due to the imperfections in the specimen microstructure. Impressively, this value is still 100 times higher than conventional dielectrics. Considering scalability and ease of integration, hexagonal boron nitride grown over large area is an excellent candidate for thermal management in two dimensional materials-based nanoelectronics.

  15. Tunable carbon nanotube-tungsten carbide nanoparticles heterostructures by vapor deposition

    SciTech Connect (OSTI)

    Xia, Min; Guo, Hongyan; Ge, Changchun [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing (China); Institute of Powder Metallurgy and Advanced Ceramics, Southwest Jiaotong University, 111, 1st Section, Northern 2nd Ring Road, Chengdu (China); Yan, Qingzhi, E-mail: qzyan@ustb.edu.cn; Lang, Shaoting [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing (China)

    2014-05-14T23:59:59.000Z

    A simple, versatile route for the synthesis of carbon nanotube (CNT)-tungsten carbide nanoparticles heterostructures was set up via vapor deposition process. For the first time, amorphous CNTs (?-CNTs) were used to immobilized tungsten carbide nanoparticles. By adjusting the synthesis and annealing temperature, ?-CNTs/amorphous tungsten carbide, ?-CNTs/W{sub 2}C, and CNTs/W{sub 2}C/WC heterostructures were prepared. This approach provides an efficient method to attach other metal carbides and other nanoparticles to carbon nanotubes with tunable properties.

  16. III-nitride quantum cascade detector grown by metal organic chemical vapor deposition

    SciTech Connect (OSTI)

    Song, Yu, E-mail: yusong@princeton.edu; Huang, Tzu-Yung; Badami, Pranav; Gmachl, Claire [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540 (United States); Bhat, Rajaram; Zah, Chung-En [Corning Incorporated, Corning, New York 14831 (United States)

    2014-11-03T23:59:59.000Z

    Quantum cascade (QC) detectors in the GaN/Al{sub x}Ga{sub 1?x}N material system grown by metal organic chemical vapor deposition are designed, fabricated, and characterized. Only two material compositions, i.e., GaN as wells and Al{sub 0.5}Ga{sub 0.5}N as barriers are used in the active layers. The QC detectors operates around 4??m, with a peak responsivity of up to ?100??A/W and a detectivity of up to 10{sup 8} Jones at the background limited infrared performance temperature around 140?K.

  17. ZnO nanorod growth by plasma-enhanced vapor phase transport with different growth durations

    SciTech Connect (OSTI)

    Kim, Chang-Yong; Oh, Hee-bong [Department of Nano Science and Engineering, Inje University, Obang-dong, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Ryu, Hyukhyun, E-mail: hhryu@inje.ac.kr [Department of Nano Science and Engineering, Center for Nano Manufacturing, Inje University, Obang-dong, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Yun, Jondo [Department of Nano Science and Engineering, Kyungnam University, Changwon, Gyeongnam 631-701 (Korea, Republic of); Lee, Won-Jae [Department of Materials and Components Engineering, Dong-Eui University, 995 Eomgwangno, Busanjin-gu, Busan 614-714 (Korea, Republic of)

    2014-09-01T23:59:59.000Z

    In this study, the structural properties of ZnO nanostructures grown by plasma-enhanced vapor phase transport (PEVPT) were investigated. Plasma-treated oxygen gas was used as the oxygen source for the ZnO growth. The structural properties of ZnO nanostructures grown for different durations were measured by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The authors comprehensively analyzed the growth of the ZnO nanostructures with different growth durations both with and without the use of plasma-treated oxygen gas. It was found that PEVPT has a significant influence on the growth of the ZnO nanorods. PEVPT with plasma-treated oxygen gas facilitated the generation of nucleation sites, and the resulting ZnO nanorod structures were more vertical than those prepared by conventional VPT without plasma-treated oxygen gas. As a result, the ZnO nanostructures grown using PEVPT showed improved structural properties compared to those prepared by the conventional VPT method.

  18. Selective charge doping of chemical vapor deposition-grown graphene by interface modification

    SciTech Connect (OSTI)

    Wang, Shengnan, E-mail: wang.shengnan@lab.ntt.co.jp; Suzuki, Satoru; Furukawa, Kazuaki; Orofeo, Carlo M.; Takamura, Makoto; Hibino, Hiroki [NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa 243-0198 (Japan)] [NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa 243-0198 (Japan)

    2013-12-16T23:59:59.000Z

    The doping and scattering effect of substrate on the electronic properties of chemical vapor deposition (CVD)-grown graphene are revealed. Wet etching the underlying SiO{sub 2} of graphene and depositing self-assembled monolayers (SAMs) of organosilane between graphene and SiO{sub 2} are used to modify various substrates for CVD graphene transistors. Comparing with the bare SiO{sub 2} substrate, the carrier mobility of CVD graphene on modified substrate is enhanced by almost 5-fold; consistently the residual carrier concentration is reduced down to 10{sup 11}?cm{sup ?2}. Moreover, scalable and reliable p- and n-type graphene and graphene p-n junction are achieved on various silane SAMs with different functional groups.

  19. Electrochromic properties of tungsten trioxide thin films prepared by photochemical vapor deposition

    SciTech Connect (OSTI)

    Maruyama, Toshiro; Kanagawa, Tetsuya (Kyoto Univ. (Japan). Dept. of Chemical Engineering)

    1994-09-01T23:59:59.000Z

    Electrochromic tungsten trioxide thin films were prepared by a photochemical vapor deposition. The source material was tungsten carbonyl. A 6 W low pressure mercury lamp was used as a light source. Amorphous tungsten trioxide thin films were obtained at a substrate temperature of 200 C. The UV radiation enhances the oxidation of tungsten, in addition to the acceleration of the deposition of the films. Reduction and oxidation of the films in a 0.3M LiClO[sub 4] propylene carbonate solution resulted in desirable changes in optimal absorption. The bleaching time was short compared to the amorphous CVD film. Coulometry indicated that the coloration efficiency was 222 cm[sup 2]/C.

  20. Vapor Trapping Growth of Single-Crystalline Graphene Flowers: Synthesis, Morphology, and Electronic Properties

    E-Print Network [OSTI]

    Zhou, Chongwu

    Vapor Trapping Growth of Single-Crystalline Graphene Flowers: Synthesis, Morphology, and Electronic-crystalline graphene flowers with grain size up to 100 m. Controlled growth of graphene flowers with four lobes and six, electron backscatter diffraction study revealed that the graphene morphology had little correlation

  1. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect (OSTI)

    Kagan, Harris; Kass, Richard; Gan, K.K.

    2014-01-23T23:59:59.000Z

    With the LHC upgrades in 2013, and further LHC upgrades scheduled in 2018, most LHC experiments are planning for detector upgrades which require more radiation hard technologies than presently available. At present all LHC experiments now have some form of diamond detector. As a result Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of all LHC experiments. Moreover CVD diamond is now being discussed as an alternative sensor material for tracking very close to the interaction region of the HL-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications. Our accomplishments include: • Developed a two U.S.companies to produce electronic grade diamond, • Worked with companies and acquired large area diamond pieces, • Performed radiation hardness tests using various proton energies: 70 MeV (Cyric, Japan), 800 MeV (Los Alamos), and 24 GeV (CERN).

  2. aqueous chemical growth: Topics by E-print Network

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

    Technische Universiteit Delft 36 Growth of Large-Area Aligned Molybdenum Nanowires by High Temperature Chemical Vapor Deposition: Synthesis, Growth Mechanism, and Device...

  3. High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Dutta, P., E-mail: pdutta2@central.uh.edu; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V. [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); Zheng, N.; Ahrenkiel, P. [Department of Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701 (United States); Martinez, J. [Materials Evaluation Laboratory, NASA Johnson Space Center, Houston, Texas 77085 (United States)

    2014-09-01T23:59:59.000Z

    We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ?10{sup 7?}cm{sup ?2}. Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300?cm{sup 2}/V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

  4. Low-temperature chemical vapor deposition of tungsten from tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Vogt, G.J.

    1982-04-01T23:59:59.000Z

    Chemical vapor deposition (CVD) of tungsten from W(CO)/sub 6/ has been investigated below 670 K as an alternate process to WF/sub 6/ CVD for coating glass microspheres. The major advantages of W(CO)/sub 6/ CVD are the elimination of the HF damage to the glass microspheres and potentially a lower deposition temperature for coating DT-filled microspheres. W(CO)/sub 6/ CVD can be utilized, in principle, to coat the microspheres with 1 to 5 ..mu..m of tungsten or to flash coat the microspheres for further coating by WF/sub 6/ CVD. Test coatings were deposited in a fluidized-bed reactor with a hydrogen carrier gas. The coatings were found to contain nearly equal portions of carbon and oxygen, ranging from 16 to 25 at.% for each element. The high carbon and oxygen concentrations are believed to result principally from the physical entrapment of chemisorbed CO molecules at the surface of the growing deposit. The general quality and adhesion of the W(CO)/sub 6/-derived coatings are unsatisfactory at this time for ICF applications.

  5. Synthesis of SiO{sub 2}/?-SiC/graphite hybrid composite by low temperature hot filament chemical vapor deposition

    SciTech Connect (OSTI)

    Zhang, Zhikun; Bi, Kaifeng; Liu, Yanhong; Qin, Fuwen; Liu, Hongzhu [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bian, Jiming, E-mail: jmbian@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang, Dong [New Energy Source Research Center of Shenyang Institute of Engineering, Shengyang 110136 (China)] [New Energy Source Research Center of Shenyang Institute of Engineering, Shengyang 110136 (China); Miao, Lihua [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Department of Computer and Mathematical Basic Teaching, Shenyang Medical College, Shenyan 110034 (China)

    2013-11-18T23:59:59.000Z

    ?-SiC thin films were synthesized directly on graphite by hot filament chemical vapor deposition at low temperature. SiH{sub 4} diluted in hydrogen was employed as the silicon source, while graphite was functioned as both substrate and carbon source for the as-grown ?-SiC films. X-ray diffraction and Fourier transform infrared analysis indicate that SiO{sub 2}/?-SiC/graphite hybrid composite was formed after post annealing treatment, and its crystalline quality can be remarkably improved under optimized annealing conditions. The possible growth mechanism was proposed based on in situ etching of graphite by reactive hydrogen radicals at the atomic level.

  6. Influence of vicinal sapphire substrate on the properties of N-polar GaN films grown by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Lin, Zhiyu; Zhang, Jincheng, E-mail: jchzhang@xidian.edu.cn; Xu, Shengrui; Chen, Zhibin; Yang, Shuangyong; Tian, Kun; Hao, Yue [Key Lab of Wide Band-Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an, Shaanxi 710071 (China); Su, Xujun [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123 (China); Shi, Xuefang [School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, Shaanxi 710071 (China)

    2014-08-25T23:59:59.000Z

    The influence of vicinal sapphire substrates on the growth of N-polar GaN films by metal-organic chemical vapor deposition is investigated. Smooth GaN films without hexagonal surface feature are obtained on vicinal substrate. Transmission electron microscope results reveal that basal-plane stacking faults are formed in GaN on vicinal substrate, leading to a reduction in threading dislocation density. Furthermore, it has been found that there is a weaker yellow luminescence in GaN on vicinal substrate than that on (0001) substrate, which might be explained by the different trends of the carbon impurity incorporation.

  7. Research on fundamental aspects of inorganic vapor and particle deposition in coal-fired systems

    SciTech Connect (OSTI)

    Rosner, D.E.

    1992-03-01T23:59:59.000Z

    In September 1990 DOE-PETC initiated at the Yale HTCRE Laboratory a systematic three-year research program directed toward providing engineers with the fundamentally-based design/optimization tools'' foreconomically predicting the dynamics of net deposit growth, and thermophysical properties of the resulting microparticulate deposits in coal-fired systems. The goal of our research in the area of mineral mattertransport is to advance the capability of making reliable engineering predictions of the dynamics of net deposit growth for surfaces exposed to the particle-laden products of coal combustion. To accomplish thisfor a wide variety of combustor types, coal types, and operating conditions, this capability must be based on a quantitative understanding of each of the important mechanisms of mineral matter transport, as well as the nature of the interactions between these substances and the prevailing fireside'' surface of deposits. This level of understanding and predictive capability could be translated into very significant cost reductions for coal-fired equipment design, development and operation. It is also expected that this research activity will not only directly benefit the ash deposition R D community -- but also generically closely related technologies of importance to DOE (e.g. hot-gas clean-up, particulate solids handling,...).

  8. Study of plasma enhanced chemical vapor deposition of boron-doped hydrogenated amorphous silicon thin films and the application to p-channel thin film transistor

    E-Print Network [OSTI]

    Nominanda, Helinda

    2004-01-01T23:59:59.000Z

    The material and process characteristics of boron doped hydrogenated amorphous silicon (a-Si:H) thin film deposited by plasma enhanced chemical vapor deposition technique (PECVD) have been studied. The goal is to apply the high quality films...

  9. CO-CATALYTIC ABSORPTION LAYERS FOR CONTROLLED LASER-INDUCED CHEMICAL VAPOR DEPOSITION OF CARBON NANOTUBES

    E-Print Network [OSTI]

    Michaelis, F.B.; Weatherup, R.S.; Bayer, B.C.; Bock, M.C.D; Sugime, H.; Caneva, S.; Robertson, J.; Baumberg, J.J.; Hofmann, S.

    2014-02-24T23:59:59.000Z

    ,38 by atomic layer deposition (ALD) using a Cambridge Nanotech Savannah system and a 200°C process with tri[methyl]aluminium and water both carried in a N2(20 sccm) flow for 200 cycles 39,40. Ta layers are sputter deposited (100W, 35sccm Ar, 3.5×10-3 mbar... it is optically compensated). Thermal CVD. CNT growth is also carried out in a custom-built cold-wall CVD chamber with a resistive graphite heater element. Samples are heated to ~670°C and annealed for 5 min in a non-reducing (~10-3 mbar vacuum) or reducing...

  10. Method and apparatus for fabricating a thin-film solar cell utilizing a hot wire chemical vapor deposition technique

    DOE Patents [OSTI]

    Wang, Qi; Iwaniczko, Eugene

    2006-10-17T23:59:59.000Z

    A thin-film solar cell is provided. The thin-film solar cell comprises an a-SiGe:H (1.6 eV) n-i-p solar cell having a deposition rate of at least ten (10) .ANG./second for the a-SiGe:H intrinsic layer by hot wire chemical vapor deposition. A method for fabricating a thin film solar cell is also provided. The method comprises depositing a n-i-p layer at a deposition rate of at least ten (10) .ANG./second for the a-SiGe:H intrinsic layer.

  11. Research on fundamental aspects of inorganic vapor and particle deposition in coal-fired systems

    SciTech Connect (OSTI)

    Rosner, D.E.

    1992-09-01T23:59:59.000Z

    In September 1990 DOE-PETC initiated at the Yale HTCRE Laboratory a systematic three-year research program directed toward providing engineers with the fundamentally-based design/optimization 'tools' for economically predicting the dynamics of net deposit growth*, and thermophysical properties of the resulting microparticulate deposits in coal-fired systems. In light of the theoretical 'program' based on the notion of self-regulation'' set forth in Rosner and Nagarajan (1987), this Task includes investigation of the effects of particle material properties and possible liquid phases on the capture properties of particulate deposits. For this purpose we exploit dynamical 'many-body' computer simulation techniques. This approach will provide the required parametric dependencies (on such quantities as incident kinetic energy and angle, mechanical and thermophysical properties of the particles,[hor ellipsis]) of a dimensionless ensemble-averaged particle capture fraction, relegating the role of direct laboratory experiment to verifying (or rejecting) some crucial features/consequences of the simulation route followed. Our ultimate goal is recommend 'sticking' and 'erosion' laws of mechanistic origin. The availability of such laws could dramatically increase the reliability of predicted deposition rates of inertially delivered particles, in the simultaneous presence of a condensed liquid phase within the growing particulate, deposit. Equally important, one could also rationally select conditions to avoid. troublesome deposition subject to other operational requirements.

  12. Carbon nanotube forests growth using catalysts from atomic layer deposition

    SciTech Connect (OSTI)

    Chen, Bingan; Zhang, Can; Esconjauregui, Santiago; Xie, Rongsi; Zhong, Guofang; Robertson, John [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Bhardwaj, Sunil [Istituto Officina dei Materiali-CNR Laboratorio TASC, s.s. 14, km 163.4, I-34012 Trieste (Italy); Sincrotone Trieste S.C.p.A., s.s. 14, km 163.4, I-34149 Trieste (Italy); Cepek, Cinzia [Istituto Officina dei Materiali-CNR Laboratorio TASC, s.s. 14, km 163.4, I-34012 Trieste (Italy)

    2014-04-14T23:59:59.000Z

    We have grown carbon nanotubes using Fe and Ni catalyst films deposited by atomic layer deposition. Both metals lead to catalytically active nanoparticles for growing vertically aligned nanotube forests or carbon fibres, depending on the growth conditions and whether the substrate is alumina or silica. The resulting nanotubes have narrow diameter and wall number distributions that are as narrow as those grown from sputtered catalysts. The state of the catalyst is studied by in-situ and ex-situ X-ray photoemission spectroscopy. We demonstrate multi-directional nanotube growth on a porous alumina foam coated with Fe prepared by atomic layer deposition. This deposition technique can be useful for nanotube applications in microelectronics, filter technology, and energy storage.

  13. QUANTIFYING GROWTH AND CALCIUM CARBONATE DEPOSITION OF CALLIARTHRON CHEILOSPORIOIDES (CORALLINALES, RHODOPHYTA)

    E-Print Network [OSTI]

    Martone, Patrick T.

    NOTE QUANTIFYING GROWTH AND CALCIUM CARBONATE DEPOSITION OF CALLIARTHRON CHEILOSPORIOIDES Station of Stanford University, Pacific Grove, California 93950, USA Growth and calcium carbonate measurement of growth and calcium carbonate deposition at each meristem. In Calliarthron, meristematic

  14. A study of heat transfer and particle motion relative to the modified chemical vapor deposition process

    SciTech Connect (OSTI)

    Choi, M.; Greif, R. (Univ. of California, Berkeley (United States)); Baum, H.R. (National Inst. of Standards and Technology, Gaithersburg, MD (United States))

    1989-11-01T23:59:59.000Z

    Heat transfer and particle motion relative to the modified chemical vapor deposition process have been studied for general values of the torch speed. Three-dimensional temperature fields have been obtained over the entire cross section of the tube and the effects of tube rotation and localized torch heating in the axial and circumferential directions have been studied. The particle trajectories have been calculated from a formulation that includes the contributions from forced flow, i.e., Poiseuille flow in the axial direction, rigid body rotation about the tube axis, and thermophoretic contributions in the axial, radial, and angular directions. The particle trajectories are helices and are shown to be strongly dependent on the tube rotation.

  15. Bifacial solar cell with SnS absorber by vapor transport deposition

    SciTech Connect (OSTI)

    Wangperawong, Artit [Stanford University, Stanford, California 94305 (United States); Department of Electrical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140 (Thailand); Hsu, Po-Chun; Yee, Yesheng; Herron, Steven M.; Clemens, Bruce M.; Cui, Yi; Bent, Stacey F., E-mail: sbent@stanford.edu [Stanford University, Stanford, California 94305 (United States)

    2014-10-27T23:59:59.000Z

    The SnS absorber layer in solar cell devices was produced by vapor transport deposition (VTD), which is a low-cost manufacturing method for solar modules. The performance of solar cells consisting of Si/Mo/SnS/ZnO/indium tin oxide (ITO) was limited by the SnS layer's surface texture and field-dependent carrier collection. For improved performance, a fluorine doped tin oxide (FTO) substrate was used in place of the Mo to smooth the topography of the VTD SnS and to make bifacial solar cells, which are potentially useful for multijunction applications. A bifacial SnS solar cell consisting of glass/FTO/SnS/CdS/ZnO/ITO demonstrated front- and back-side power conversion efficiencies of 1.2% and 0.2%, respectively.

  16. Carbon nanowalls grown by microwave plasma enhanced chemical vapor deposition during the carbonization of polyacrylonitrile fibers

    SciTech Connect (OSTI)

    Li Jiangling; Su Shi; Kundrat, Vojtech; Abbot, Andrew M.; Ye, Haitao [School of Engineering and Applied Science, Aston University, Birmingham B4 7ET (United Kingdom); Zhou Lei [Department of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); Mushtaq, Fajer [Department of Mechanical Engineering, ETH Zurich, Zurich 8092 (Switzerland); Ouyang Defang [School of Life and Health Science, Aston University, Birmingham B4 7ET (United Kingdom); James, David; Roberts, Darren [Thermo Fisher Scientific, Stafford House, Hemel Hempstead HP2 7GE (United Kingdom)

    2013-01-14T23:59:59.000Z

    We used microwave plasma enhanced chemical vapor deposition (MPECVD) to carbonize an electrospun polyacrylonitrile (PAN) precursor to form carbon fibers. Scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the fibers at different evolution stages. It was found that MPECVD-carbonized PAN fibers do not exhibit any significant change in the fiber diameter, whilst conventionally carbonized PAN fibers show a 33% reduction in the fiber diameter. An additional coating of carbon nanowalls (CNWs) was formed on the surface of the carbonized PAN fibers during the MPECVD process without the assistance of any metallic catalysts. The result presented here may have a potential to develop a novel, economical, and straightforward approach towards the mass production of carbon fibrous materials containing CNWs.

  17. Vapor deposition of platinum alloyed nickel aluminide coatings Z. Yu , K.P. Dharmasena, D.D. Hass, H.N.G. Wadley

    E-Print Network [OSTI]

    Wadley, Haydn

    Vapor deposition of platinum alloyed nickel aluminide coatings Z. Yu , K.P. Dharmasena, D.D. Hass at high temperature. It requires the chemical vapor deposition of aluminum on a nickel rich superalloy substrate that has been pre-coated with several microns of electrodeposited platinum. Here, we show

  18. Gas jet assisted vapor deposition of yttria stabilized zirconia D. D. Hass and H. N. G. Wadleya

    E-Print Network [OSTI]

    Wadley, Haydn

    Gas jet assisted vapor deposition of yttria stabilized zirconia D. D. Hass and H. N. G. Wadleya February 2009 A gas jet assisted electron beam evaporation process for synthesizing yttria stabilized zirconia YSZ coatings has recently been reported. The process uses a rarefied inert gas jet to entrain

  19. Temperature dependent photoluminescence of lateral polarity junctions of metal organic chemical vapor deposition grown GaN

    E-Print Network [OSTI]

    Nabben, Reinhard

    implantation of Cu, Li and Ag into silicon doped GaN films grown by Metalorganic Chemical Vapor Deposition temperature (700-900°C) annealing. Low temperature (6K) photoluminescence (PL) for Cu-implanted GaN showed recovery of standard crystalline GaN features. Additional donor-acceptor pair features are observed below 3

  20. Climate Dependency of Tree Growth Suppressed by Acid Deposition

    E-Print Network [OSTI]

    Lapenas, Andrei G.

    uptake). These soil changes coincided with decreased diameter growth and a suppression of climateClimate Dependency of Tree Growth Suppressed by Acid Deposition Effects on Soils in Northwest Russia G R E G O R Y B . L A W R E N C E , * , A N D R E I G . L A P E N I S , D A N B E R G G R E N

  1. Reactor design for uniform chemical vapor deposition-grown films without substrate rotation

    SciTech Connect (OSTI)

    Wanlass, M.

    1987-03-17T23:59:59.000Z

    A reactor vessel is described for chemical vapor deposition of a uniform semiconductor film on a substrate, comprising: a generally cylindrical reaction chamber for receiving a substrate and a flow of reaction gas capable of depositing a film on the substrate under the conditions of the chamber, the chamber having upper and lower portion and being oriented about a vertical axis; a supporting means having a substrate support surface generally perpendicular to the vertical axis for carrying the substrate within the lower portion of the reaction chamber in a predetermined relative position with respect to the upper portion of the reaction chamber, the upper portion including a cylindrically shaped confinement chamber. The confinement chamber has a smaller diameter than the lower portion of the reaction chamber and is positioned above the substrate support surface; and a means for introducing a reaction gas into the confinement chamber in a nonaxial direction so as to direct the reaction gas into the lower portion of the reaction chamber with a non-axial flow having a rotational component with respect to the vertical axis. In this way the reaction gas defines an inward vortex flow pattern with respect to the substrate surface.

  2. Synthesis of multiferroic Er-Fe-O thin films by atomic layer and chemical vapor deposition

    SciTech Connect (OSTI)

    Mantovan, R., E-mail: roberto.mantovan@mdm.imm.cnr.it; Vangelista, S.; Wiemer, C.; Lamperti, A.; Tallarida, G. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Chikoidze, E.; Dumont, Y. [GEMaC, Université de Versailles St. Quentin en Yvelines-CNRS, Versailles (France); Fanciulli, M. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Milano (Italy)

    2014-05-07T23:59:59.000Z

    R-Fe-O (R?=?rare earth) compounds have recently attracted high interest as potential new multiferroic materials. Here, we report a method based on the solid-state reaction between Er{sub 2}O{sub 3} and Fe layers, respectively grown by atomic layer deposition and chemical vapor deposition, to synthesize Er-Fe-O thin films. The reaction is induced by thermal annealing and evolution of the formed phases is followed by in situ grazing incidence X-ray diffraction. Dominant ErFeO{sub 3} and ErFe{sub 2}O{sub 4} phases develop following subsequent thermal annealing processes at 850?°C in air and N{sub 2}. Structural, chemical, and morphological characterization of the layers are conducted through X-ray diffraction and reflectivity, time-of-flight secondary ion-mass spectrometry, and atomic force microscopy. Magnetic properties are evaluated by magnetic force microscopy, conversion electron Mössbauer spectroscopy, and vibrating sample magnetometer, being consistent with the presence of the phases identified by X-ray diffraction. Our results constitute a first step toward the use of cost-effective chemical methods for the synthesis of this class of multiferroic thin films.

  3. Characterization of diamond-like nanocomposite thin films grown by plasma enhanced chemical vapor deposition

    SciTech Connect (OSTI)

    Santra, T. S.; Liu, C. H. [Institute of Nanoengineering and Microsystems (NEMS), National Tsing Hua University, Hsinchu, Taiwan 30043 (China); Bhattacharyya, T. K. [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal (India); Patel, P. [Department of Electrical and Computer Engineering, University of Illinois at Urbana Champaign, Urbana, Illinois 61801 (United States); Barik, T. K. [School of Applied Sciences, Haldia Institute of Technology, Haldia 721657, Purba Medinipur, West Bengal (India)

    2010-06-15T23:59:59.000Z

    Diamond-like nanocomposite (DLN) thin films, comprising the networks of a-C:H and a-Si:O were deposited on pyrex glass or silicon substrate using gas precursors (e.g., hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, or their different combinations) mixed with argon gas, by plasma enhanced chemical vapor deposition technique. Surface morphology of DLN films was analyzed by atomic force microscopy. High-resolution transmission electron microscopic result shows that the films contain nanoparticles within the amorphous structure. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to determine the structural change within the DLN films. The hardness and friction coefficient of the films were measured by nanoindentation and scratch test techniques, respectively. FTIR and XPS studies show the presence of C-C, C-H, Si-C, and Si-H bonds in the a-C:H and a-Si:O networks. Using Raman spectroscopy, we also found that the hardness of the DLN films varies with the intensity ratio I{sub D}/I{sub G}. Finally, we observed that the DLN films has a better performance compared to DLC, when it comes to properties like high hardness, high modulus of elasticity, low surface roughness and low friction coefficient. These characteristics are the critical components in microelectromechanical systems (MEMS) and emerging nanoelectromechanical systems (NEMS).

  4. Preparation of amorphous electrochromic tungsten oxide and molybdenum oxide by plasma enhanced chemical vapor deposition

    SciTech Connect (OSTI)

    Tracy, C.E.; Benson, D.K.

    1986-09-01T23:59:59.000Z

    Preliminary experiments have been performed to probe the feasibility of using plasma enhanced chemical vapor deposition (PE--CVD) to prepare electrochromic thin films of tungsten oxide and molybdenum oxide by plasma reaction of WF/sub 6/, W(CO)/sub 6/, and Mo(CO)/sub 6/ with oxygen. Thin films produced in a 300 W, electrodeless, radio-frequency (rf), capacitive discharge were found to be electrochromic when tested with either liquid or solid electrolytes. Optical spectroscopy was performed on two electrochromic coatings after Li/sup +/ ion insertion from a propylene carbonate liquid electrolyte. Broad absorption peaks at --900 nm for WO/sub 3/ and 600 nm for MoO/sub 3/ were observed. Optical results for PE--CVD MoO/sub 3/ films differ from those reported for evaporated MoO/sub 3/ films which have an absorption peak at --800 nm. The shorter wavelength absorption in the PE--CVD MoO/sub 3/ films offers the potential for fabricating electrochromic devices with higher contrast ratios and less color change. Optical emission spectroscopy, Auger, and x-ray diffraction analyses indicate these thin film deposits to be predominantly amorphous tungsten and molybdenum oxides.

  5. Step-edge-induced resistance anisotropy in quasi-free-standing bilayer chemical vapor deposition graphene on SiC

    SciTech Connect (OSTI)

    Ciuk, Tymoteusz [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Cakmakyapan, Semih; Ozbay, Ekmel [Department of Electrical and Electronics Engineering, Department of Physics, Nanotechnology Research Center, Bilkent University, 06800 Bilkent, Ankara (Turkey); Caban, Piotr; Grodecki, Kacper; Pasternak, Iwona; Strupinski, Wlodek, E-mail: wlodek.strupinski@itme.edu.pl [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Krajewska, Aleksandra [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw (Poland); Szmidt, Jan [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland)

    2014-09-28T23:59:59.000Z

    The transport properties of quasi-free-standing (QFS) bilayer graphene on SiC depend on a range of scattering mechanisms. Most of them are isotropic in nature. However, the SiC substrate morphology marked by a distinctive pattern of the terraces gives rise to an anisotropy in graphene's sheet resistance, which may be considered an additional scattering mechanism. At a technological level, the growth-preceding in situ etching of the SiC surface promotes step bunching which results in macro steps ~10 nm in height. In this report, we study the qualitative and quantitative effects of SiC steps edges on the resistance of epitaxial graphene grown by chemical vapor deposition. We experimentally determine the value of step edge resistivity in hydrogen-intercalated QFS-bilayer graphene to be ~190 ??m for step height hS = 10 nm and provide proof that it cannot originate from mechanical deformation of graphene but is likely to arise from lowered carrier concentration in the step area. Our results are confronted with the previously reported values of the step edge resistivity in monolayer graphene over SiC atomic steps. In our analysis, we focus on large-scale, statistical properties to foster the scalable technology of industrial graphene for electronics and sensor applications.

  6. X-ray diffraction analysis of InGaP/GaAs heterointerfaces grown by metalorganic chemical vapor deposition

    SciTech Connect (OSTI)

    Nittono, T.; Hyuga, F. [NTT System Electronics Laboratories 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-01 (Japan)] [NTT System Electronics Laboratories 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-01 (Japan)

    1997-03-01T23:59:59.000Z

    InGaP/GaAs heterointerfaces grown by metalorganic chemical vapor deposition have been characterized by a high-resolution x-ray diffraction analysis of multiple quantum well structures. The flow of AsH{sub 3} to InGaP surface produces an InGaAs-like interfacial layer at the GaAs-on-InGaP interface, indicating P atoms of the InGaP surface are easily replaced by As atoms. The flow of PH{sub 3} to GaAs surface, on the other hand, does not make any detectable interfacial layer, indicating that almost no As atoms of the GaAs surface are replaced by P atoms. It is also found that the flow of trimethylgallium (TMG) to the InGaP surface produces a GaP-like interfacial layer. This interfacial layer is probably formed by the reaction between TMG and excessive P atoms on the InGaP surface or residual PH{sub 3} in the growth chamber. {copyright} {ital 1997 American Institute of Physics.}

  7. Optical coatings of variable refractive index and high laser-resistance from physical-vapor-deposited perfluorinated amorphous polymer

    DOE Patents [OSTI]

    Chow, R.; Loomis, G.E.; Thomas, I.M.

    1999-03-16T23:59:59.000Z

    Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (ca. 1.10--1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm. 2 figs.

  8. Optical coatings of variable refractive index and high laser-resistance from physical-vapor-deposited perfluorinated amorphous polymer

    DOE Patents [OSTI]

    Chow, Robert (Livermore, CA); Loomis, Gary E. (Livermore, CA); Thomas, Ian M. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (.about.1.10-1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm.

  9. Massively parallel computation of 3D flow and reactions in chemical vapor deposition reactors

    SciTech Connect (OSTI)

    Salinger, A.G.; Shadid, J.N.; Hutchinson, S.A.; Hennigan, G.L.; Devine, K.D.; Moffat, H.K.

    1997-12-01T23:59:59.000Z

    Computer modeling of Chemical Vapor Deposition (CVD) reactors can greatly aid in the understanding, design, and optimization of these complex systems. Modeling is particularly attractive in these systems since the costs of experimentally evaluating many design alternatives can be prohibitively expensive, time consuming, and even dangerous, when working with toxic chemicals like Arsine (AsH{sub 3}): until now, predictive modeling has not been possible for most systems since the behavior is three-dimensional and governed by complex reaction mechanisms. In addition, CVD reactors often exhibit large thermal gradients, large changes in physical properties over regions of the domain, and significant thermal diffusion for gas mixtures with widely varying molecular weights. As a result, significant simplifications in the models have been made which erode the accuracy of the models` predictions. In this paper, the authors will demonstrate how the vast computational resources of massively parallel computers can be exploited to make possible the analysis of models that include coupled fluid flow and detailed chemistry in three-dimensional domains. For the most part, models have either simplified the reaction mechanisms and concentrated on the fluid flow, or have simplified the fluid flow and concentrated on rigorous reactions. An important CVD research thrust has been in detailed modeling of fluid flow and heat transfer in the reactor vessel, treating transport and reaction of chemical species either very simply or as a totally decoupled problem. Using the analogy between heat transfer and mass transfer, and the fact that deposition is often diffusion limited, much can be learned from these calculations; however, the effects of thermal diffusion, the change in physical properties with composition, and the incorporation of surface reaction mechanisms are not included in this model, nor can transitions to three-dimensional flows be detected.

  10. Effect of e-beam irradiation on graphene layer grown by chemical vapor deposition

    SciTech Connect (OSTI)

    Iqbal, M. Z.; Kumar Singh, Arun; Iqbal, M. W.; Seo, Sunae; Eom, Jonghwa [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)

    2012-04-15T23:59:59.000Z

    We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO{sub 2} substrates to make tens of micron scale devices for Raman spectroscopy study. The effect of electron beam (e-beam) irradiation of various doses (600 to 12 000 {mu}C/cm{sup 2}) on CVD grown graphene has been examined by using Raman spectroscopy. It is found that the radiation exposures result in the appearance of the strong disorder D band attributed the damage to the lattice. The evolution of peak frequencies, intensities, and widths of the main Raman bands of CVD graphene is analyzed as a function of defect created by e-beam irradiation. Especially, the D and G peak evolution with increasing radiation dose follows the amorphization trajectory, which suggests transformation of graphene to the nanocrystalline and then to amorphous form. We have also estimated the strain induced by e-beam irradiation in CVD graphene. These results obtained for CVD graphene are in line with previous findings reported for the mechanically exfoliated graphene [D. Teweldebrhan and A. A. Balandin, Appl. Phys. Lett. 94, 013101 (2009)]. The results have important implications for CVD graphene characterization and device fabrication, which rely on the electron microscopy.

  11. Growth mode evolution of hafnium oxide by atomic layer deposition

    SciTech Connect (OSTI)

    Nie, Xianglong; Ma, Fei; Ma, Dayan, E-mail: madayan@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi (China); Xu, Kewei [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China and Department of Physics and Opt-electronic Engineering, Xi'an University of Arts and Science, Xi'an 710065, Shaanxi (China)

    2014-01-15T23:59:59.000Z

    HfO{sub 2} thin films were deposited using tetrakis-ethylmethylamido hafnium and H{sub 2}O as precursors on silicon by atomic layer deposition (ALD). The morphology and microstructures at different ALD cycles were characterized by atomic force microscopy and high-resolution transmission electron microscopy. Based on the height–height correlation function and power spectral density function, quantitative analysis of surface morphologies was performed. Three characteristic dimensions (?{sub 1}, ?{sub 2}, and ?{sub 3}) corresponding to three surface structures, islands, local and global fluctuations, were identified. The evolution of ALD growth mode at range of the three critical scales was investigated, respectively. It suggests the transformation of growth mode from quasi two-dimensional layer-by-layer to three-dimensional island for global fluctuations.

  12. Design of a compact ultrahigh vacuum-compatible setup for the analysis of chemical vapor deposition processes

    SciTech Connect (OSTI)

    Weiss, Theodor; Nowak, Martin; Zielasek, Volkmar, E-mail: zielasek@uni-bremen.de; Bäumer, Marcus [Institut für Angewandte und Physikalische Chemie, Universität Bremen, Leobener Straße UFT, D-28359 Bremen (Germany); Mundloch, Udo; Kohse-Höinghaus, Katharina [Physikalische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld (Germany)

    2014-10-15T23:59:59.000Z

    Optimizing thin film deposition techniques requires contamination-free transfer from the reactor into an ultrahigh vacuum (UHV) chamber for surface science analysis. A very compact, multifunctional Chemical Vapor Deposition (CVD) reactor for direct attachment to any typical UHV system for thin film analysis was designed and built. Besides compactness, fast, easy, and at the same time ultimately clean sample transfer between reactor and UHV was a major goal. It was achieved by a combination of sample manipulation parts, sample heater, and a shutter mechanism designed to fit all into a NW38 Conflat six-ways cross. The present reactor design is versatile to be employed for all commonly employed variants of CVD, including Atomic Layer Deposition. A demonstration of the functionality of the system is provided. First results of the setup (attached to an Omicron Multiprobe x-ray photoelectron spectroscopy system) on the temperature dependence of Pulsed Spray Evaporation-CVD of Ni films from Ni acetylacetonate as the precursor demonstrate the reactor performance and illustrate the importance of clean sample transfer without breaking vacuum in order to obtain unambiguous results on the quality of CVD-grown thin Ni films. The widely applicable design holds promise for future systematic studies of the fundamental processes during chemical vapor deposition or atomic layer deposition.

  13. Development of nanodiamond foils for H- stripping to Support the Spallation Neutron Source (SNS) using hot filament chemical vapor deposition

    SciTech Connect (OSTI)

    Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL

    2014-01-01T23:59:59.000Z

    Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a small foil about the size of a postage stamp is critical to the operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control film thickness. The results are discussed in the light of development of nanodiamond foils that will be able to withstand a few MW proton beam and hopefully will be able to be used after possible future upgrades to the SNS to greater than a 3MW beam.

  14. Condensed phase conversion and growth of nanorods and other materials instead of from vapor

    DOE Patents [OSTI]

    Geohegan, David B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Puretzky, Alex A. (Knoxville, TN); Fan, Xudong (Oak Ridge, TN)

    2010-10-19T23:59:59.000Z

    Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed phase matrix material instead of from vapor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

  15. Robofurnace: A semi-automated laboratory chemical vapor deposition system for high-throughput nanomaterial synthesis and process discovery

    SciTech Connect (OSTI)

    Oliver, C. Ryan; Westrick, William; Koehler, Jeremy; Brieland-Shoultz, Anna; Anagnostopoulos-Politis, Ilias; Cruz-Gonzalez, Tizoc [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Hart, A. John, E-mail: ajhart@mit.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2013-11-15T23:59:59.000Z

    Laboratory research and development on new materials, such as nanostructured thin films, often utilizes manual equipment such as tube furnaces due to its relatively low cost and ease of setup. However, these systems can be prone to inconsistent outcomes due to variations in standard operating procedures and limitations in performance such as heating and cooling rates restrict the parameter space that can be explored. Perhaps more importantly, maximization of research throughput and the successful and efficient translation of materials processing knowledge to production-scale systems, relies on the attainment of consistent outcomes. In response to this need, we present a semi-automated lab-scale chemical vapor deposition (CVD) furnace system, called “Robofurnace.” Robofurnace is an automated CVD system built around a standard tube furnace, which automates sample insertion and removal and uses motion of the furnace to achieve rapid heating and cooling. The system has a 10-sample magazine and motorized transfer arm, which isolates the samples from the lab atmosphere and enables highly repeatable placement of the sample within the tube. The system is designed to enable continuous operation of the CVD reactor, with asynchronous loading/unloading of samples. To demonstrate its performance, Robofurnace is used to develop a rapid CVD recipe for carbon nanotube (CNT) forest growth, achieving a 10-fold improvement in CNT forest mass density compared to a benchmark recipe using a manual tube furnace. In the long run, multiple systems like Robofurnace may be linked to share data among laboratories by methods such as Twitter. Our hope is Robofurnace and like automation will enable machine learning to optimize and discover relationships in complex material synthesis processes.

  16. Inversion by metalorganic chemical vapor deposition from N- to Ga-polar gallium nitride and its application to multiple quantum well light-emitting diodes

    SciTech Connect (OSTI)

    Hosalli, A. M.; Van Den Broeck, D. M.; Bedair, S. M. [Department of Electrical and Computer Engineering, NCSU, Raleigh, North Carolina 27695 (United States)] [Department of Electrical and Computer Engineering, NCSU, Raleigh, North Carolina 27695 (United States); Bharrat, D.; El-Masry, N. A. [Department of Material Science and Engineering, NCSU, Raleigh, North Carolina 27695 (United States)] [Department of Material Science and Engineering, NCSU, Raleigh, North Carolina 27695 (United States)

    2013-12-02T23:59:59.000Z

    We demonstrate a metalorganic chemical vapor deposition growth approach for inverting N-polar to Ga-polar GaN by using a thin inversion layer grown with high Mg flux. The introduction of this inversion layer allowed us to grow p-GaN films on N-polar GaN thin film. We have studied the dependence of hole concentration, surface morphology, and degree of polarity inversion for the inverted Ga-polar surface on the thickness of the inversion layer. We then use this approach to grow a light emitting diode structure which has the MQW active region grown on the advantageous N-polar surface and the p-layer grown on the inverted Ga-polar surface.

  17. Microstructure and interface control of GaN/MgAl{sub 2}O{sub 4} grown by metalorganic chemical vapor deposition: Substrate-orientation dependence

    SciTech Connect (OSTI)

    He, G.; Chikyow, T. [Advanced Electric Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Chichibu, Shigefusa F. [CANTech, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan)

    2011-07-15T23:59:59.000Z

    GaN films with single-crystal and polycrystalline structure were deposited on (111) and (100) MgAl{sub 2}O{sub 4} substrates by metalorganic chemical vapor deposition using a substrate modified by chemical etching and thermal passivation. The interface structure and chemical bonding state of the GaN/MgAl{sub 2}O{sub 4} interface was investigated using angle-resolved x-ray photoelectron spectroscopy and resulting valence band spectra. Our results indicate that the Al{sub 2}O{sub 3} buffered layer induced by thermal passivation of the (111) substrate remains unchanged during GaN deposition, which is primarily responsible for the epitaxial growth of GaN on (111) MgAl{sub 2}O{sub 4} substrate. However, for the as-processed (100) substrate, interfacial reactions take place between the formed MgO-terminated surface and GaN films and GaN with a polycrystalline structure on (100) substrate forms. From the interface engineering viewpoint, the appropriate interface modification will allow control of the interface reaction to obtain high-quality GaN films for future optoelectronic devices.

  18. Characteristics of ultra low-k nanoporous and fluorinated silica based films prepared by plasma enhanced chemical vapor deposition

    SciTech Connect (OSTI)

    Abbasi-Firouzjah, M. [Laser and Plasma Research Institute, Shahid Beheshti University G.C., Evin, Tehran 1983963113 (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University G.C., Evin, Tehran 1983963113 (Iran, Islamic Republic of); Shokri, B. [Laser and Plasma Research Institute, Shahid Beheshti University G.C., Evin, Tehran 1983963113 (Iran, Islamic Republic of) [Laser and Plasma Research Institute, Shahid Beheshti University G.C., Evin, Tehran 1983963113 (Iran, Islamic Republic of); Physics Department, Shahid Beheshti University G.C., Evin, Tehran (Iran, Islamic Republic of)

    2013-12-07T23:59:59.000Z

    Low dielectric constant (low-k) silica based films were deposited on p-type silicon and polycarbonate substrates by radio frequency (RF) plasma enhanced chemical vapor deposition method at low temperature. A mixture of tetraethoxysilane vapor, oxygen, and tetrafluoromethane (CF{sub 4}) was used for the deposition of the films in forms of two structures called as SiO{sub x}C{sub y} and SiO{sub x}C{sub y}F{sub z}. Properties of the films were controlled by amount of porosity and fluorine content in the film matrix. The influence of RF power and CF{sub 4} flow on the elemental composition, deposition rate, surface roughness, leakage current, refractive index, and dielectric constant of the films were characterized. Moreover, optical emission spectroscopy was applied to monitor the plasma process at the different parameters. Electrical characteristics of SiO{sub x}C{sub y} and SiO{sub x}C{sub y}F{sub z} films with metal-oxide-semiconductor structure were investigated using current-voltage analysis to measure the leakage current and breakdown field, as well as capacitance-voltage analysis to obtain the film's dielectric constant. The results revealed that SiO{sub x}C{sub y} films, which are deposited at lower RF power produce more leakage current, meanwhile the dielectric constant and refractive index of these films decreased mainly due to the more porosity in the film structure. By adding CF{sub 4} in the deposition process, fluorine, the most electronegative and the least polarized atom, doped into the silica film and led to decrease in the refractive index and the dielectric constant. In addition, no breakdown field was observed in the electrical characteristics of SiO{sub x}C{sub y}F{sub z} films and the leakage current of these films reduced by increment of the CF{sub 4} flow.

  19. As-grown deep-level defects in n-GaN grown by metal-organic chemical vapor deposition on freestanding GaN

    SciTech Connect (OSTI)

    Chen Shang; Ishikawa, Kenji; Hori, Masaru [Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Honda, Unhi; Shibata, Tatsunari; Matsumura, Toshiya; Tokuda, Yutaka [Aichi Institute of Technology, Yakusa, Toyota 470-0392 (Japan); Ueda, Hiroyuki; Uesugi, Tsutomu; Kachi, Tetsu [Toyota Central R and D Laboratories, Inc., Yokomichi, Nagakute 480-1192 (Japan)

    2012-09-01T23:59:59.000Z

    Traps of energy levels E{sub c}-0.26 and E{sub c}-0.61 eV have been identified as as-grown traps in n-GaN grown by metal-organic chemical vapor deposition by using deep level transient spectroscopy of the Schottky contacts fabricated by resistive evaporation. The additional traps of E{sub c}-0.13 and E{sub c}-0.65 eV have been observed in samples whose contacts are deposited by electron-beam evaporation. An increase in concentration of the E{sub c}-0.13 and E{sub c}-0.65 eV traps when approaching the interface between the contact and the GaN film supports our argument that these traps are induced by electron-beam irradiation. Conversely, the depth profiles of as-grown traps show different profiles between several samples with increased or uniform distribution in the near surface below 50 nm. Similar profiles are observed in GaN grown on a sapphire substrate. We conclude that the growth process causes these large concentrations of as-grown traps in the near-surface region. It is speculated that the finishing step in the growth process should be an essential issue in the investigation of the surface state of GaN.

  20. Atomic layer deposition of TiN films Growth and electrical behavior down to

    E-Print Network [OSTI]

    Atomic layer deposition of TiN films Growth and electrical behavior down to sub-nanometer scale Hao Van Bui #12;ATOMIC LAYER DEPOSITION OF TiN FILMS GROWTH AND ELECTRICAL BEHAVIOR DOWN TO SUBD. Thesis - University of Twente, Enschede, the Netherlands Title: Atomic layer deposition of TiN films

  1. Effect of NH{sub 3} on the low pressure chemical vapor deposition of TiO{sub 2} film at low temperature using tetrakis(diethylamino)titanium and oxygen

    SciTech Connect (OSTI)

    Song Xuemei; Takoudis, Christos G. [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 and Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)

    2007-03-15T23:59:59.000Z

    The effect of NH{sub 3} on TiO{sub 2} film deposition using tetrakis(diethylamino)titanium (TDEAT) and O{sub 2} as source gases in a low pressure chemical vapor deposition reactor was studied at low temperatures ranging from 100 to 250 deg. C. TiO{sub 2} film is traditionally deposited at temperature above 300 deg. C using oxygen-based Ti precursors, such as titanium tetraisopropoxide. In this study, the authors demonstrate that a combination of both reactive precursors, i.e., TDEAT and NH{sub 3}, is an effective technique for TiO{sub 2} film deposition at lower temperatures, albeit with some nitrogen incorporation. It was found that films can be formed at temperatures as low as 100 deg. C when NH{sub 3} is used. At higher temperatures, the growth rate of TiO{sub 2} films deposited using NH{sub 3} is higher than that of films deposited without NH{sub 3} by up to one order of magnitude. X-ray photoelectron spectroscopy data show that NH{sub 3} enhances the formation of TiNO and TiN, and x-ray diffraction analysis shows that all as-deposited films have amorphous structure. Both x-ray photoelectron spectroscopy and secondary ion mass spectroscopy depth profiles show that nitrogen, carbon, and oxygen are uniformly distributed throughout the film. The mechanism of enhancement of growth rate using NH{sub 3} is also discussed.

  2. Hot-filament chemical vapor deposition chamber and process with multiple gas inlets

    DOE Patents [OSTI]

    Deng, Xunming; Povolny, Henry S.

    2004-06-29T23:59:59.000Z

    A thin film deposition method uses a vacuum confinement cup that employs a dense hot filament and multiple gas inlets. At least one reactant gas is introduced into the confinement cup both near and spaced apart from the heated filament. An electrode inside the confinement cup is used to generate plasma for film deposition. The method is used to deposit advanced thin films (such as silicon based thin films) at a high quality and at a high deposition rate.

  3. Improving chemical vapor deposition graphene conductivity using molybdenum trioxide: An in-situ field effect transistor study

    SciTech Connect (OSTI)

    Han, Cheng [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China) [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China); Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Lin, Jiadan; Xiang, Du [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)] [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Wang, Chaocheng; Wang, Li [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China)] [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China); Chen, Wei [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore) [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

    2013-12-23T23:59:59.000Z

    By using in situ field effect transistor characterization integrated with molecular beam epitaxy technique, we demonstrate the strong surface transfer p-type doping effect of single layer chemical vapor deposition (CVD) graphene, through the surface functionalization of molybdenum trioxide (MoO{sub 3}) layer. After doping, both the hole and electron mobility of CVD graphene are nearly retained, resulting in significant enhancement of graphene conductivity. With coating of 10 nm MoO{sub 3}, the conductivity of CVD graphene can be increased by about 7 times, showing promising application for graphene based electronics and transparent, conducting, and flexible electrodes.

  4. Photoresponse properties of large-area MoS{sub 2} atomic layer synthesized by vapor phase deposition

    SciTech Connect (OSTI)

    Luo, Siwei; Qi, Xiang, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn; Ren, Long; Hao, Guolin; Fan, Yinping; Liu, Yundan; Han, Weijia; Zang, Chen; Li, Jun; Zhong, Jianxin, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, People's Republic of China Laboratory for Quantum Engineering and Micro-Nano Energy Technology, and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan 411105 (China)

    2014-10-28T23:59:59.000Z

    Photoresponse properties of a large area MoS{sub 2} atomic layer synthesized by vapor phase deposition method without any catalyst are studied. Scanning electron microscopy, atomic force microscopy, Raman spectrum, and photoluminescence spectrum characterizations confirm that the two-dimensional microstructures of MoS{sub 2} atomic layer are of high quality. Photoelectrical results indicate that the as-prepared MoS{sub 2} devices have an excellent sensitivity and a good reproducibility as a photodetector, which is proposed to be ascribed to the potential-assisted charge separation mechanism.

  5. MOMENTUM AND THERMAL BOUNDARY-LAYER THICKNESS IN A STAGNATION FLOW CHEMICAL VAPOR DEPOSITION REACTOR

    E-Print Network [OSTI]

    Dandy, David

    REACTOR DAVID S. DANDY AND JUNGHEUM YUN Department of Chemical Engineering Colorado State University Fort deposition pedestal reactors. Expressions for the velocity and temperature profiles within the boundary

  6. Organic polymer thin films deposited on silicon and copper by plasma-enhanced chemical vapor deposition method and

    E-Print Network [OSTI]

    Boo, Jin-Hyo

    Chun-Dong, Jangan- Gu, Suwon 440-746, South Korea J. H. Boo Center for Advanced Plasma Surface Technology be grown under various deposition conditions. © 2005 American Vacuum Society. DOI: 10.1116/1.1946714 I as a dielectric and optical coating to inhibit corrosion.1,2 More- over, with increasing integration density

  7. Research on fundamental aspects of inorganic vapor and particle deposition in coal-fired systems. Seventh quarterly technical report, March 6, 1992--June 5, 1992

    SciTech Connect (OSTI)

    Rosner, D.E.

    1992-06-01T23:59:59.000Z

    Parallel research studies are underway on the following interrelated and fundamental subjects; Geometrical Approach to Determining the Sticking Probability of Particles Impacting on Convex Solid Surfaces; Correlations for High Schmidt Number Particle Deposition From Dilute Flowing Rational Engineering Suspensions; Average Capture Probability of Arriving Particles Which Are Distributed With ResPect to ImPact VelocitY and Incidence Angle (Relative to Deposit Substrate); Experimental and Theoretical Studies of Vapor Infiltration of Non-isothermal Granular Deposits; Effective Area/Volume of Populations of `MicroPorous` Aerosol Particles (Compact and `Fractal` Quasispherical Aggregates); Effects of Radiative Heat Transfer on the Coagulation Rates of Combustion-Generated Particles; Structure-Sensitivity of Total Mass Deposition Rates from Combustion Product Streams containing Coagulation-Aged Populations of Aggregated Primary Particles; and Na{sub 2}SO{sub 4} Chemical Vapor Deposition From Chlorine-containing Coal-Derived Gases.

  8. Semi-insulating crystalline silicon formed by oxygen doping during low-temperature chemical vapor deposition

    E-Print Network [OSTI]

    Semi-insulating crystalline silicon formed by oxygen doping during low-temperature chemical vapor) In this letter we demonstrate the use of oxygen as a dopant in silicon to create semi-insulating, crystalline of the films exhibit classical characteristics of space-charge-limited current associated with insulators

  9. Simulation of chemical vapor infiltration and deposition based on 3D images: a local scale approach

    E-Print Network [OSTI]

    Boyer, Edmond

    infiltration of ceramic matrix composites is presented. This computational model requires a 3D representation/reaction problems; Random walks; 3D image-based modeling 1. Introduction Ceramic Matrix Composites and Carbon with a matrix. One of the most efficient ones is Chemical Vapor Infiltration (CVI), by which gaseous precursors

  10. Maskless deposition technique for the physical vapor deposition of thin film and multilayer coatings with subnanometer precision and accuracy

    DOE Patents [OSTI]

    Vernon, Stephen P. (Pleasanton, CA); Ceglio, Natale M. (Livermore, CA)

    2000-01-01T23:59:59.000Z

    The invention is a method for the production of axially symmetric, graded and ungraded thickness thin film and multilayer coatings that avoids the use of apertures or masks to tailor the deposition profile. A motional averaging scheme permits the deposition of uniform thickness coatings independent of the substrate radius. Coating uniformity results from an exact cancellation of substrate radius dependent terms, which occurs when the substrate moves at constant velocity. If the substrate is allowed to accelerate over the source, arbitrary coating profiles can be generated through appropriate selection and control of the substrate center of mass equation of motion. The radial symmetry of the coating profile is an artifact produced by orbiting the substrate about its center of mass; other distributions are obtained by selecting another rotation axis. Consequently there is a direct mapping between the coating thickness and substrate equation of motion which can be used to tailor the coating profile without the use of masks and apertures.

  11. Growth of novel micro-structured carbon thin films by using ultrashort-pulse laser deposition

    E-Print Network [OSTI]

    ;! ! )! 1.1 pulsed-laser deposition PLD PLD ultra-short pulse laser deposition uPLD PLD [1] figure 1 seed electron PLD PLD nano-second ns Lab 325 femto-second fs ultra-short pulse laser deposition uPLD) u! ! "! Growth of novel micro-structured carbon thin films by using ultrashort-pulse laser

  12. Vapor-Phase Metalation by Atomic Layer Deposition in a Metal-Organic Framework

    E-Print Network [OSTI]

    encompass deposition onto micro- and nanopowders14 and coating of nanoparticle films15 as well as aerogel coating of porous materials that exhibit ultrahigh-aspect ratios.12,13 To date, some striking examples

  13. ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition

    SciTech Connect (OSTI)

    Xu, W.Z.; Ye, Z.Z.; Zeng, Y.J.; Zhu, L.P.; Zhao, B.H.; Jiang, L.; Lu, J.G.; He, H.P.; Zhang, S.B. [State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    2006-04-24T23:59:59.000Z

    We report a breakthrough in fabricating ZnO homojunction light-emitting diode by metal organic chemical vapor deposition. Using NO plasma, we are able to grow p-type ZnO thin films on n-type bulk ZnO substrates. The as-grown films on glass substrates show hole concentration of 10{sup 16}-10{sup 17} cm{sup -3} and mobility of 1-10 cm{sup 2} V{sup -1} s{sup -1}. Room-temperature photoluminescence spectra reveal nitrogen-related emissions. A typical ZnO homojunction shows rectifying behavior with a turn-on voltage of about 2.3 V. Electroluminescence at room temperature has been demonstrated with band-to-band emission at I=40 mA and defect-related emissions in the blue-yellow spectrum range.

  14. Influence of anticlinal growth on upper Miocene turbidite deposits, Elk Hills field, Kern County, California

    SciTech Connect (OSTI)

    Reid, S.A. (Bechtel Petroleum Operations, Inc., Tupman, CA (United States)); McJannet, G.S. (Dept. of Energy, Tupman, CA (United States))

    1991-02-01T23:59:59.000Z

    Growth of subsea anticlines during deposition of the upper Miocene 24Z and 26R sandstones at Elk Hills caused the development of several sinuous, lenticular sand bodies. later structural growth enhanced the trap characteristics of these sandstones. Both sandstones are in the uppermost portion of the Elk Hills Shale Member of the Monterey Formation and contain channel-fill and overbank deposits of sand-rich turbidite systems. At the onset of turbidite deposition, low relief subsea anticlines separated broad basins which progressively deepened to the northeast. Channel-fill deposits of coarse-grained sand generally followed the axes of these northwest-southeast-trending basins. At several sites, channel-fill deposits also spilled north across anticlinal axes into the next lower basins. Wide bands of overbank sand and mud were deposited at sand body edges on the flat basin floors. Midway through turbidite deposition, a period of anticlinal growth substantially raised subsea relief. Channel-fill deposits continued in narrower basins but passed north into deeper basin only around well-defined sites at the anticlines' downplunge termini. Narrow basin shapes and higher anticline relief prevented significant overbank deposition. With Pliocene to Holocene uplift of the late Miocene structural trends, stratigraphic mounding of the north-directed channel-fill deposits helped create structural domes at 24Z, 2B and Northwest Stevens pools. In sand bodies lacking significant overbank deposits prevented oil entrapment in sand bodies deposited at times of low anticlinal relief.

  15. Vapor deposition of water on graphitic surfaces: Formation of amorphous ice, bilayer ice, ice I, and liquid water

    SciTech Connect (OSTI)

    Lupi, Laura; Kastelowitz, Noah; Molinero, Valeria, E-mail: Valeria.Molinero@utah.edu [Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850 (United States)

    2014-11-14T23:59:59.000Z

    Carbonaceous surfaces are a major source of atmospheric particles and could play an important role in the formation of ice. Here we investigate through molecular simulations the stability, metastability, and molecular pathways of deposition of amorphous ice, bilayer ice, and ice I from water vapor on graphitic and atomless Lennard-Jones surfaces as a function of temperature. We find that bilayer ice is the most stable ice polymorph for small cluster sizes, nevertheless it can grow metastable well above its region of thermodynamic stability. In agreement with experiments, the simulations predict that on increasing temperature the outcome of water deposition is amorphous ice, bilayer ice, ice I, and liquid water. The deposition nucleation of bilayer ice and ice I is preceded by the formation of small liquid clusters, which have two wetting states: bilayer pancake-like (wetting) at small cluster size and droplet-like (non-wetting) at larger cluster size. The wetting state of liquid clusters determines which ice polymorph is nucleated: bilayer ice nucleates from wetting bilayer liquid clusters and ice I from non-wetting liquid clusters. The maximum temperature for nucleation of bilayer ice on flat surfaces, T{sub B}{sup max} is given by the maximum temperature for which liquid water clusters reach the equilibrium melting line of bilayer ice as wetting bilayer clusters. Increasing water-surface attraction stabilizes the pancake-like wetting state of liquid clusters leading to larger T{sub B}{sup max} for the flat non-hydrogen bonding surfaces of this study. The findings of this study should be of relevance for the understanding of ice formation by deposition mode on carbonaceous atmospheric particles, including soot.

  16. Effects of thermal annealing on the structural, mechanical, and tribological properties of hard fluorinated carbon films deposited by plasma enhanced chemical vapor deposition

    SciTech Connect (OSTI)

    Maia da Costa, M.E.H.; Baumvol, I.J.R.; Radke, C.; Jacobsohn, L.G.; Zamora, R.R.M.; Freire, F.L. Jr. [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Cx. Postal 3807, Rio de Janeiro, RJ, 22453-970 (Brazil); Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 91540-000 (Brazil); Los Alamos National Laboratory, Materials Science and Technology Division, P. O. Box 1663, Los Alamos, New Mexico 87545 (United States); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Cx. Postal 3807, Rio de Janeiro, RJ, 22453-970 (Brazil)

    2004-11-01T23:59:59.000Z

    Hard amorphous fluorinated carbon films (a-C:F) deposited by plasma enhanced chemical vapor deposition were annealed in vacuum for 30 min in the temperature range of 200-600 deg. C. The structural and compositional modifications were followed by several analytical techniques: Rutherford backscattering spectrometry (RBS), elastic recoil detection analysis (ERDA), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Nanoidentation measurements and lateral force microscopy experiments were carried out in order to provide the film hardness and the friction coefficient, respectively. The internal stress and contact angle were also measured. RBS, ERDA, and XPS results indicate that both fluorine and hydrogen losses occur for annealing temperatures higher than 300 deg. C. Raman spectroscopy shows a progressive graphitization upon annealing, while the surface became slightly more hydrophobic as revealed by the increase of the contact angle. Following the surface wettability reduction, a decrease of the friction coefficient was observed. These results highlight the influence of the capillary condensation on the nanoscale friction. The film hardness and the internal stress are constant up to 300 deg. C and decrease for higher annealing temperatures, showing a direct correlation with the atomic density of the films. Since the thickness variation is negligible, the mass loss upon thermal treatment results in amorphous structures with a lower degree of cross-linking, explaining the deterioration of the mechanical properties of the a-C:F films.

  17. Thermal expansion of low-pressure chemical vapor deposition polysilicon films

    E-Print Network [OSTI]

    Ballarini, Roberto

    polysilicon films were deposited on the sub- strates by LPCVD in a hot-walled horizontal tube fur- nace with an inner diameter of 225 mm, using SiH4 at a flow rate of 100 sccm and a pressure of 300 mtorr J. Mater

  18. The Progress on Low-Cost, High-Quality, High-Temperature Superconducting Tapes Deposited by the Combustion Chemical Vapor Deposition Process

    SciTech Connect (OSTI)

    Shoup, S.S.; White, M.K.; Krebs, S.L.; Darnell, N.; King, A.C.; Mattox, D.S.; Campbell, I.H.; Marken, K.R.; Hong, S.; Czabaj, B.; Paranthaman, M.; Christen, H.M.; Zhai, H.-Y. Specht, E.

    2008-06-24T23:59:59.000Z

    The innovative Combustion Chemical Vapor Deposition (CCVD) process is a non-vacuum technique that is being investigated to enable next generation products in several application areas including high-temperature superconductors (HTS). In combination with the Rolling Assisted Biaxially Textured Substrate (RABiTS) technology, the CCVD process has significant promise to provide low-cost, high-quality lengths of YBCO coated conductor. Over 100 meter lengths of both Ni and Ni-W (3 at. Wt.%) substrates with a surface roughness of 12-18 nm were produced. The CCVD technology has been used to deposit both buffer layer coatings as well as YBCO superconducting layers. Buffer layer architecture of strontium titanate (SrTiO{sub 3}) and ceria (CeO{sub 2}) have been deposited by CCVD on textured nickel substrates and optimized to appropriate thicknesses and microstructures to provide templates for growing PLD YBCO with a J{sub c} of 1.1 MA/cm{sup 2} at 77 K and self-field. The CCVD buffer layers have been scaled to meter plus lengths with good epitaxial uniformity along the length. A short sample cut from one of the lengths enabled high critical current density PLD YBCO. Films of CCVD YBCO superconductors have been grown on single crystal substrates with critical current densities over 1 MA/cm{sup 2}. In addition, superconducting YBCO films with an I{sub c} of 60 A/cm-width (J{sub c} = 1.5 MA/cm{sup 2}) were grown on ORNL RABiTS (CeO{sub 2}/YSZ/Y{sub 2}O{sub 3}/Ni/Ni-3W) using CCVD process.

  19. Prevention of biofouling in seawater desalination via initiated chemical vapor deposition (iCVD)

    E-Print Network [OSTI]

    Yang, Rong, Ph. D. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    Biofouling, the undesirable settlement and growth of organisms, occurs immediately when a clean surface is immersed in natural seawater. It is a universal problem and the bottleneck for seawater desalination, which reduces ...

  20. Visible Light Photocatalysis with Nitrogen-Doped Titanium Dioxide Nanoparticles Prepared by Plasma Assisted Chemical Vapor Deposition

    SciTech Connect (OSTI)

    Buzby,S.; Barakat, M.; Lin, H.; Ni, C.; Rykov, S.; Chen, J.; Shah, S.

    2006-01-01T23:59:59.000Z

    Nitrogen-doped TiO{sub 2} nanoparticles were synthesized via plasma assisted metal organic chemical vapor deposition. Nitrogen dopant concentration was varied from 0 to 1.61 at. %. The effect of nitrogen ion doping on visible light photocatalysis has been investigated. Samples were analyzed by various analytical techniques such as x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy, and near-edge x-ray absorption fine structure. Titanium tetraisopropoxide was used as the titanium precursor, while rf-plasma-decomposed ammonia was used as the source for nitrogen doping. The N-doped TiO{sub 2} nanoparticles were deposited on stainless steel mesh under a flow of Ar and O2 gases at 600 {sup o}C in a tube reactor. The photocatalytic activity of the prepared N-doped TiO{sub 2} samples was tested by the degradation of 2-chlorophenol (2-CP) in an aqueous solution using a visible lamp equipped with an UV filter. The efficiency of photocatalytic oxidation of 2-CP was measured using high performance liquid chromatography. Results obtained revealed the formation of N-doped TiO{sub 2} samples as TiO{sub 2-x}N{sub x}, and a corresponding increase in the visible light photocatalytic activity.

  1. Crystalline SiGe films grown on Si substrates using laser-assisted plasma-enhanced chemical vapor deposition at low temperature

    SciTech Connect (OSTI)

    Lee, C.-T.; Cheng, J.-H.; Lee, H.-Y. [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China) and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan, Taiwan 701 (China); Department of Electro-Optical Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China)

    2007-08-27T23:59:59.000Z

    Compared with conventional plasma-enhanced chemical vapor deposition, laser-assisted plasma-enhanced chemical vapor deposition (LAPECVD) can be used to deposit crystalline SiGe films on Si substrates at low temperature. In the LAPECVD system, a CO{sub 2} laser with a wavelength of 10.6 {mu}m was utilized to assist the pyrolytical decomposition of SiH{sub 4} and GeH{sub 4} reactant gases. The resultant Si{sub 0.78}Ge{sub 0.22} films were obtained and verified through the use of the Auger electron spectroscopy measurement. As the diffraction pattern of a glancing incident angle X-ray diffraction measurement had indicated, several significant diffraction peaks corresponding to a diamond-cubic structure at (111) (220), and (311) were clearly observed. Crystalline SiGe films were also identified by the electron diffraction pattern of high-resolution transmission electron microscopy images.

  2. An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes

    E-Print Network [OSTI]

    Grujicic, Mica

    Growth of carbon nanotubes during transition-metal particles catalytically-assisted thermal decomposition of the transition-metal particles and onto the surface of carbon nanotubes, carbon atom attachment to the growing. Carbon nanotubes are generally processed by laser ablation of carbon rods e.g. [7], a direct current arc

  3. Multiwalled Carbon Nanotube Forest Grown via Chemical Vapor Deposition from Iron Catalyst Nanoparticles, by XPS

    SciTech Connect (OSTI)

    Jensen, David S.; Kanyal, Supriya S.; Madaan, Nitesh; Vail, Michael A.; Dadson, Andrew; Engelhard, Mark H.; Linford, Matthew R.

    2013-09-25T23:59:59.000Z

    Carbon nanotubes (CNTs) have unique chemical and physical properties. Herein, we report an XPS analysis of a forest of multiwalled CNTs using monochromatic Al K? radiation. Survey scans show only one element: carbon. The carbon 1s peak is centered 284.5 eV. The C 1s envelope also shows the expected ? ? ?* shake-up peak at ca. 291 eV. The valence band and carbon KVV Auger signals are presented. When patterned, the CNT forests can be used as a template for subsequent deposition of metal oxides to make thin layer chromatography plates.1-3

  4. Reactor design for uniform chemical vapor deposition-grown films without substrate rotation

    SciTech Connect (OSTI)

    Wanlass, Mark (Golden, CO)

    1987-01-01T23:59:59.000Z

    A quartz reactor vessel for growth of uniform semiconductor films includes a vertical, cylindrical reaction chamber in which a substrate-supporting pedestal provides a horizontal substrate-supporting surface spaced on its perimeter from the chamber wall. A cylindrical confinement chamber of smaller diameter is disposed coaxially above the reaction chamber and receives reaction gas injected at a tangent to the inside chamber wall, forming a helical gas stream that descends into the reaction chamber. In the reaction chamber, the edge of the substrate-supporting pedestal is a separation point for the helical flow, diverting part of the flow over the horizontal surface of the substrate in an inwardly spiraling vortex.

  5. Reactor design for uniform chemical vapor deposition-grown films without substrate rotation

    DOE Patents [OSTI]

    Wanlass, M.

    1985-02-19T23:59:59.000Z

    A quartz reactor vessel for growth of uniform semiconductor films includes a vertical, cylindrical reaction chamber in which a substrate-supporting pedestal provides a horizontal substrate-supporting surface spaced on its perimeter from the chamber wall. A cylindrical confinement chamber of smaller diameter is disposed coaxially above the reaction chamber and receives reaction gas injected at a tangent to the inside chamber wall, forming a helical gas stream that descends into the reaction chamber. In the reaction chamber, the edge of the substrate-supporting pedestal is a separation point for the helical flow, diverting part of the flow over the horizontal surface of the substrate in an inwardly spiraling vortex.

  6. Mass densification and defect restoration in chemical vapor deposition silicon dioxide film using Ar plasma excited by microwave

    SciTech Connect (OSTI)

    Kawase, Kazumasa, E-mail: Kawase.Kazumasa@ak.MitsubishiElectric.co.jp; Motoya, Tsukasa; Uehara, Yasushi [Advanced Technology R and D Center, Mitsubishi Electric Corporation, 8-1-1 Tsukaguchi-honmachi, Amagasaki, Hyogo 661-8661 (Japan); Teramoto, Akinobu; Suwa, Tomoyuki; Ohmi, Tadahiro [New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)

    2014-09-01T23:59:59.000Z

    Silicon dioxide (SiO{sub 2}) films formed by chemical vapor deposition (CVD) have been treated with Ar plasma excited by microwave. The changes of the mass densities, carrier trap densities, and thicknesses of the CVD-SiO{sub 2} films with the Ar plasma treatments were investigated. The mass density depth profiles were estimated with X-Ray Reflectivity (XRR) analysis using synchrotron radiation. The densities of carrier trap centers due to defects of Si-O bond network were estimated with X-ray Photoelectron Spectroscopy (XPS) time-dependent measurement. The changes of the thicknesses due to the oxidation of Si substrates were estimated with the XRR and XPS. The mass densities of the CVD-SiO{sub 2} films are increased by the Ar plasma treatments. The carrier trap densities of the films are decreased by the treatments. The thicknesses of the films are not changed by the treatments. It has been clarified that the mass densification and defect restoration in the CVD-SiO{sub 2} films are caused by the Ar plasma treatments without the oxidation of the Si substrates.

  7. Analysis of buoyancy and tube rotation relative to the modified chemical vapor deposition process

    SciTech Connect (OSTI)

    Choi, M.; Lin, Y.T.; Greif, R. (Univ. of California, Berkeley (USA))

    1990-11-01T23:59:59.000Z

    The secondary flows resulting from buoyancy effects in respect to the MCVD process have been studied in a rotating horizontal tube using a perturbation analysis. The three-dimensional secondary flow fields have been determined at several axial locations in a tube whose temperature varies in both the axial and circumferential directions for different rotational speeds. For small rotational speeds, buoyancy and axial convection are dominant and the secondary flow patterns are different in the regions near and far from the torch. For moderate rotational speeds, the effects of buoyancy, axial and angular convection are all important in the region far from the torch where there is a spiraling secondary flow. For large rotational speeds, only buoyancy and angular convection effects are important and no spiraling secondary motions occurs far downstream. Compared with thermophoresis, the important role of buoyancy in determining particle trajectories in MCVD is presented. As the rotational speed increases, the importance of the secondary flow decreases and the thermophoretic contribution vecomes more important. It is noted that thermophoresis is considered to be the main cause of particle deposition in the MCVD process.

  8. Ion Beam Deposition of Thin Films: Growth Processes and Nanostructure Formation

    SciTech Connect (OSTI)

    Hofsaess, Hans C. [II. Physikalisches Institut, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)

    2004-12-01T23:59:59.000Z

    Ion beam deposition is a process far from thermodynamic equilibrium and is in particular suited to grow metastable thin films with diamond-like properties, such as tetrahedral amorphous carbon (ta-C) and cubic boron nitride (c-BN). In this contribution the atomistic description of the deposition and growth processes are reviewed and compared to experimental results, obtained from mass selected ion beam deposition. The focus will be set to the nucleation and growth processes of boron nitride as a model system for ion based thin film formation. Furthermore, recent examples for nanostructure formation in ion deposited compound thin films will be presented. Ion beam deposited metal-carbon nano-composite thin films exhibit a variety of different morphologies such as rather homogeneous nanocluster distributions embedded in an a-C matrix, but also the self-organized formation of nanoscale multilayer structures.

  9. Comparison of precursor infiltration into polymer thin films via atomic layer deposition and sequential vapor infiltration using in-situ quartz crystal microgravimetry

    SciTech Connect (OSTI)

    Padbury, Richard P.; Jur, Jesse S., E-mail: jsjur@ncsu.edu [Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-07-01T23:59:59.000Z

    Previous research exploring inorganic materials nucleation behavior on polymers via atomic layer deposition indicates the formation of hybrid organic–inorganic materials that form within the subsurface of the polymer. This has inspired adaptations to the process, such as sequential vapor infiltration, which enhances the diffusion of organometallic precursors into the subsurface of the polymer to promote the formation of a hybrid organic–inorganic coating. This work highlights the fundamental difference in mass uptake behavior between atomic layer deposition and sequential vapor infiltration using in-situ methods. In particular, in-situ quartz crystal microgravimetry is used to compare the mass uptake behavior of trimethyl aluminum in poly(butylene terephthalate) and polyamide-6 polymer thin films. The importance of trimethyl aluminum diffusion into the polymer subsurface and the subsequent chemical reactions with polymer functional groups are discussed.

  10. Issues associated with the metalorganic chemical vapor deposition of ScGaN and YGaN alloys.

    SciTech Connect (OSTI)

    Koleske, Daniel David; Knapp, James Arthur; Lee, Stephen Roger; Crawford, Mary Hagerott; Creighton, James Randall; Cross, Karen Charlene; Thaler, Gerald

    2009-07-01T23:59:59.000Z

    The most energy efficient solid state white light source will likely be a combination of individually efficient red, green, and blue LED. For any multi-color approach to be successful the efficiency of deep green LEDs must be significantly improved. While traditional approaches to improve InGaN materials have yielded incremental success, we proposed a novel approach using group IIIA and IIIB nitride semiconductors to produce efficient green and high wavelength LEDs. To obtain longer wavelength LEDs in the nitrides, we attempted to combine scandium (Sc) and yttrium (Y) with gallium (Ga) to produce ScGaN and YGaN for the quantum well (QW) active regions. Based on linear extrapolation of the proposed bandgaps of ScN (2.15 eV), YN (0.8 eV) and GaN (3.4 eV), we expected that LEDs could be fabricated from the UV (410 nm) to the IR (1600 nm), and therefore cover all visible wavelengths. The growth of these novel alloys potentially provided several advantages over the more traditional InGaN QW regions including: higher growth temperatures more compatible with GaN growth, closer lattice matching to GaN, and reduced phase separation than is commonly observed in InGaN growth. One drawback to using ScGaN and YGaN films as the active regions in LEDs is that little research has been conducted on their growth, specifically, are there metalorganic precursors that are suitable for growth, are the bandgaps direct or indirect, can the materials be grown directly on GaN with a minimal defect formation, as well as other issues related to growth. The major impediment to the growth of ScGaN and YGaN alloys was the low volatility of metalorganic precursors. Despite this impediment some progress was made in incorporation of Sc and Y into GaN which is detailed in this report. Primarily, we were able to incorporate up to 5 x 10{sup 18} cm{sup -3} Y atoms into a GaN film, which are far below the alloy concentrations needed to evaluate the YGaN optical properties. After a no-cost extension was granted on this program, an additional more 'liquid-like' Sc precursor was evaluated and the nitridation of Sc metals on GaN were investigated. Using the Sc precursor, dopant level quantities of Sc were incorporated into GaN, thereby concluding the growth of ScGaN and YGaN films. Our remaining time during the no-cost extension was focused on pulsed laser deposition of Sc metal films on GaN, followed by nitridation in the MOCVD reactor to form ScN. Finally, GaN films were deposited on the ScN thin films in order to study possible GaN dislocation reduction.

  11. Calibrated vapor generator source

    DOE Patents [OSTI]

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26T23:59:59.000Z

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  12. Calibrated vapor generator source

    DOE Patents [OSTI]

    Davies, John P. (Idaho Falls, ID); Larson, Ronald A. (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Hall, Harold J. (Idaho Falls, ID); Stoddard, Billy D. (Idaho Falls, ID); Davis, Sean G. (Idaho Falls, ID); Kaser, Timothy G. (Idaho Falls, ID); Conrad, Frank J. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  13. A comparison of the marginal adaptation of cathode-arc vapor-deposited titanium and cast base metal copings.

    E-Print Network [OSTI]

    Wu, Jean C; Lai, Li-Chung; Sheets, Cherilyn G; Earthman, James; Newcomb, Robert

    2011-01-01T23:59:59.000Z

    titanium reacts with oxygen, hydrogen, and nitrogen, whichdesired titanium coping thickness is achieved, nitrogen gaspurity nitrogen gas was added to the titanium vapor after

  14. Correlation analysis of tree growth, climate, and acid deposition in the Lake States. Forest Service research paper

    SciTech Connect (OSTI)

    Holdaway, M.R.

    1990-01-01T23:59:59.000Z

    The report describes research designed to detect subtle regional tree growth trends related to sulfate (SO{sub 4}) deposition in the Lake States. Correlation methods were used to analyze climatic and SO{sub 4} deposition. Effects of SO{sub 4} deposition are greater on climatically stressed trees, especially pine species on dry sites, than on unstressed trees. Jack pine growth shows the strongest correlation to both climate and acid deposition.

  15. Atmospheric Pressure Chemical Vapor Deposition of High Silica SiO2-TiO2 Antireflective Thin Films for Glass Based Solar Panels

    SciTech Connect (OSTI)

    Klobukowski, Erik R [ORNL; Tenhaeff, Wyatt E [ORNL; McCamy, James [PPG; Harris, Caroline [PPG; Narula, Chaitanya Kumar [ORNL

    2013-01-01T23:59:59.000Z

    The atmospheric pressure chemical vapor deposition (APCVD) of SiO2-TiO2 thin films employing [[(tBuO)3Si]2O-Ti(OiPr)2], which can be prepared from commercially available materials, results in antireflective thin films on float glass under industrially relevant manufacturing conditions. It was found that while the deposition temperature had an effect on the SiO2:TiO2 ratio, the thickness was dependent on the time of deposition. This study shows that it is possible to use APCVD employing a single source precursor containing titanium and silicon to produce thin films on float glass with high SiO2:TiO2 ratios.

  16. Understanding the Nanotube Growth Mechanism: A Strategy to Control Nanotube Chirality during Chemical Vapor Deposition Synthesis

    E-Print Network [OSTI]

    Gomez Gualdron, Diego Armando 1983-

    2012-10-26T23:59:59.000Z

    For two decades, single-wall carbon nanotubes (SWCNTs) have captured the attention of the research community, and become one of the flagships of nanotechnology. Due to their remarkable electronic and optical properties, SWCNTs are prime candidates...

  17. Understanding the Nanotube Growth Mechanism: A Strategy to Control Nanotube Chirality during Chemical Vapor Deposition Synthesis 

    E-Print Network [OSTI]

    Gomez Gualdron, Diego Armando 1983-

    2012-10-26T23:59:59.000Z

    for the creation of novel and revolutionary electronic, medical, and energy technologies. However, a major stumbling block in the exploitation of nanotube-based technologies is the lack of control of nanotube structure (chirality) during synthesis, which...

  18. Gold catalyzed growth of silicon nanowires by plasma enhanced chemical vapor deposition

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    , Cambridge CB2 1EW, United Kingdom R. E. Dunin-Borkowski Department of Materials Science and Metallurgy to low-dimensional physics, and they can be used as nanotechnology building blocks to reach higher device-temperature synthesis from its phase diagram, because the Ga­Si system has a very low eutectic temperature.16 However

  19. Mat. Res. Soc. Symp. Proc. Vol. 612 2000 Materials Research Society VOLATILE LIQUID PRECURSORS FOR THE CHEMICAL VAPOR DEPOSITION

    E-Print Network [OSTI]

    . These tungsten oxide films can be used as part of electrochromic windows, mirrors or displays. Physical in microelectronics.5 CVD using both W(CO)6 vapor and oxygen gas, O2, has produced electrochromic films of tungsten

  20. Sculptured thin films and glancing angle deposition: Growth mechanics and applications

    E-Print Network [OSTI]

    Robbie, Kevin

    Sculptured thin films and glancing angle deposition: Growth mechanics and applications K. Robbiea thin films with three dimensional microstructure controlled on the 10 nm scale were fabricated'' columnar thin film microstructure into desired forms ranging from zigzag shaped to helical to four

  1. Essential role of catalysts (Mn, Au, and Sn) in the vapor liquid solid growth kinematics of ZnS nanowires

    SciTech Connect (OSTI)

    Rehman, S.; Shehzad, M. A.; Hafeez, M.; Bhatti, A. S., E-mail: asbhatti@comsats.edu.pk [Center for Micro and Nano Devices (CMND), Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2014-01-14T23:59:59.000Z

    In this paper, we demonstrate that surface energy of the catalyst is a vital parameter for the growth rate, self doping of the self assembled nanowires synthesized by employing vapor liquid solid growth technique. The synthesis of ZnS nanowires was done by selectively using three different catalysts (Mn, Au, and Sn), where Au, is the most common catalyst, was used as a reference. The distinctive difference in the growth rate was due to the surface energy of the metal alloy droplet and the interface energies, as explained theoretically using thermodynamic approach. We have found that the activation energy of diffusion of (Zn, S) species in the catalyst droplet was low in Sn (0.41?eV for Zn and 0.13?eV for S) and high in Mn (1.79?eV for Zn and 0.61?eV for S) compared to Au (0.62?eV for Zn and 0.21?eV for S) catalyzed ZnS nanostructures. The thermodynamic calculations predicted the growth rates of Sn (7.5?nm/s) catalyzed nanowires was faster than Au (5.1?nm/s) and Mn (4.6?nm/s) catalyzed ZnS nanostructures, which were in agreement with the experimental results. Finally, the location of the catalyst as dopant in the grown nanostructure was predicted and compared with experimental observations.

  2. Thermoelectric properties of lattice-matched AlInN alloy grown by metal organic chemical vapor deposition

    E-Print Network [OSTI]

    Gilchrist, James F.

    Thermoelectric properties of lattice-matched AlInN alloy grown by metal organic chemical vapor Seebeck coefficient and resistance measurement system for thermoelectric materials in the thin disk geometry Rev. Sci. Instrum. 83, 025101 (2012) High-temperature thermoelectric properties of Cu1­xInTe2

  3. Bundles of carbon nanotubes generated by vapor-phase growth Maohui Ge and Klaus Sattler

    E-Print Network [OSTI]

    Sattler, Klaus

    show that another hollow carbon structure is possible to form under such high density conditions. We report the observation of assemblies of carbon nano- tubes in the form of bundles. The bundles. It is located horizontally on the flat graphite substrate. It is separated from other deposited carbon nano

  4. Research on fundamental aspects of inorganic vapor and particle deposition in coal-fired systems. Quarterly technical report, December 6, 1991--March 5, 1992

    SciTech Connect (OSTI)

    Rosner, D.E.

    1992-03-01T23:59:59.000Z

    In September 1990 DOE-PETC initiated at the Yale HTCRE Laboratory a systematic three-year research program directed toward providing engineers with the fundamentally-based design/optimization ``tools`` foreconomically predicting the dynamics of net deposit growth, and thermophysical properties of the resulting microparticulate deposits in coal-fired systems. The goal of our research in the area of mineral mattertransport is to advance the capability of making reliable engineering predictions of the dynamics of net deposit growth for surfaces exposed to the particle-laden products of coal combustion. To accomplish thisfor a wide variety of combustor types, coal types, and operating conditions, this capability must be based on a quantitative understanding of each of the important mechanisms of mineral matter transport, as well as the nature of the interactions between these substances and the prevailing ``fireside`` surface of deposits. This level of understanding and predictive capability could be translated into very significant cost reductions for coal-fired equipment design, development and operation. It is also expected that this research activity will not only directly benefit the ash deposition R&D community -- but also generically closely related technologies of importance to DOE (e.g. hot-gas clean-up, particulate solids handling,...).

  5. Measurement and modeling of Ar/H2/CH4 arc jet discharge chemical vapor deposition reactors. I. Intercomparison

    E-Print Network [OSTI]

    Bristol, University of

    of thin, polycrystalline diamond films, and the results of a two-dimensional r,z computer model domains. dc arc jets offer considerable advantages as a route to deposition of polycrystalline diamond

  6. Research on fundamental aspects of inorganic vapor and particle deposition in coal-fired systems. Eighth quarterly technical progress report, June 6, 1992--September 5, 1992

    SciTech Connect (OSTI)

    Rosner, D.E.

    1992-09-01T23:59:59.000Z

    In September 1990 DOE-PETC initiated at the Yale HTCRE Laboratory a systematic three-year research program directed toward providing engineers with the fundamentally-based design/optimization `tools` for economically predicting the dynamics of net deposit growth*, and thermophysical properties of the resulting microparticulate deposits in coal-fired systems. In light of the theoretical `program` based on the notion of ``self-regulation`` set forth in Rosner and Nagarajan (1987), this Task includes investigation of the effects of particle material properties and possible liquid phases on the capture properties of particulate deposits. For this purpose we exploit dynamical `many-body` computer simulation techniques. This approach will provide the required parametric dependencies (on such quantities as incident kinetic energy and angle, mechanical and thermophysical properties of the particles,{hor_ellipsis}) of a dimensionless ensemble-averaged particle capture fraction, relegating the role of direct laboratory experiment to verifying (or rejecting) some crucial features/consequences of the simulation route followed. Our ultimate goal is recommend `sticking` and `erosion` laws of mechanistic origin. The availability of such laws could dramatically increase the reliability of predicted deposition rates of inertially delivered particles, in the simultaneous presence of a condensed liquid phase within the growing particulate, deposit. Equally important, one could also rationally select conditions to avoid. troublesome deposition subject to other operational requirements.

  7. A three-dimensional analysis of the flow and heat transfer for the modified chemical vapor deposition process including buoyancy, variable properties, and tube rotation

    SciTech Connect (OSTI)

    Lin, Y.T.; Choi, M.; Greif, R. (Univ. of California, Berkeley (USA))

    1991-05-01T23:59:59.000Z

    A study has been made of the heat transfer, flow, and particle deposition relative to the modified chemical vapor deposition (MCVD) process. The effects of variable properties, buoyancy, and tube rotation have been included in the study. The resulting three-dimensional temperature and velocity fields have been obtained for a range of conditions. The effects of buoyancy result in asymmetric temperature and axial velocity profiles with respect to the tube axis. Variable properties cause significant variations in the axial velocity along the tube and in the secondary flow in the region near the torch. Particle trajectories are shown to be strongly dependent on the tube rotation and are helices for large rotational speeds. The component of secondary flow in the radial direction is compared to the thermophoretic velocity, which is the primary cause of particle deposition in the MCVD process. Over the central portion of the tube the radial component of the secondary flow is most important in determining the motion of the particles.

  8. Condensed phase conversion and growth of nanorods instead of from vapor

    DOE Patents [OSTI]

    Geohegan, David B.; Seals, Roland D.; Puretzky, Alex A.; Fan, Xudong

    2005-08-02T23:59:59.000Z

    Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed chase matrix material instead of from vacor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

  9. Current induced annealing and electrical characterization of single layer graphene grown by chemical vapor deposition for future interconnects in VLSI circuits

    SciTech Connect (OSTI)

    Prasad, Neetu, E-mail: neetu.prasad@south.du.ac.in, E-mail: neetu23686@gmail.com; Kumari, Anita; Bhatnagar, P. K.; Mathur, P. C. [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021 (India); Bhatia, C. S. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2014-09-15T23:59:59.000Z

    Single layer graphene (SLG) grown by chemical vapor deposition (CVD) has been investigated for its prospective application as horizontal interconnects in very large scale integrated circuits. However, the major bottleneck for its successful application is its degraded electronic transport properties due to the resist residual trapped in the grain boundaries and on the surface of the polycrystalline CVD graphene during multi-step lithographic processes, leading to increase in its sheet resistance up to 5 M?/sq. To overcome this problem, current induced annealing has been employed, which helps to bring down the sheet resistance to 10?k?/sq (of the order of its initial value). Moreover, the maximum current density of ?1.2?×?10{sup 7?}A/cm{sup 2} has been obtained for SLG (1?×?2.5??m{sup 2}) on SiO{sub 2}/Si substrate, which is about an order higher than that of conventionally used copper interconnects.

  10. Toward epitaxially grown two-dimensional crystal hetero-structures: Single and double MoS{sub 2}/graphene hetero-structures by chemical vapor depositions

    SciTech Connect (OSTI)

    Lin, Meng-Yu [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Chang, Chung-En [Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan (China); Wang, Cheng-Hung [Institute of Display, National Chiao-Tung University, Hsinchu, Taiwan (China); Su, Chen-Fung; Chen, Chi [Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Lee, Si-Chen [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Lin, Shih-Yen, E-mail: shihyen@gate.sinica.edu.tw [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan (China)

    2014-08-18T23:59:59.000Z

    Uniform large-size MoS{sub 2}/graphene hetero-structures fabricated directly on sapphire substrates are demonstrated with layer-number controllability by chemical vapor deposition (CVD). The cross-sectional high-resolution transmission electron microscopy (HRTEM) images provide the direct evidences of layer numbers of MoS{sub 2}/graphene hetero-structures. Photo-excited electron induced Fermi level shift of the graphene channel are observed on the single MoS{sub 2}/graphene hetero-structure transistors. Furthermore, double hetero-structures of graphene/MoS{sub 2}/graphene are achieved by CVD fabrication of graphene layers on top of the MoS{sub 2}, as confirmed by the cross-sectional HRTEM. These results have paved the possibility of epitaxially grown multi-hetero-structures for practical applications.

  11. Co-Pt core-shell nanostructured catalyst prepared by selective chemical vapor pulse deposition of Pt on Co as a cathode in polymer electrolyte fuel cells

    SciTech Connect (OSTI)

    Seo, Sang-Joon; Chung, Ho-Kyoon [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon, Gyeonggi 440-746 (Korea, Republic of); Yoo, Ji-Beom [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon, Gyeonggi 440-746, Korea and School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi 440-746 (Korea, Republic of); Chae, Heeyeop; Seo, Seung-Woo; Min Cho, Sung, E-mail: sungmcho@skku.edu [School of Chemical Engineering, Sungkyunkwan University, Suwon, Gyeonggi 440-746 (Korea, Republic of)

    2014-01-15T23:59:59.000Z

    A new type of PtCo/C catalyst for use as a cathode in polymer electrolyte fuel cells was prepared by selective chemical vapor pulse deposition (CVPD) of Pt on the surface of Co. The activity of the prepared catalyst for oxygen reduction was higher than that of a catalyst prepared by sequential impregnation (IMP) with the two metallic components. This catalytic activity difference occurs because the former catalyst has smaller Pt crystallites that produce stronger Pt-Co interactions and have a larger Pt surface area. Consequently, the CVPD catalyst has a great number of Co particles that are in close contact with the added Pt. The Pt surface was also electronically modified by interactions with Co, which were stronger in the CVPD catalyst than in the IMP catalyst, as indicated by X-ray diffraction, X-ray photoemission spectroscopy, and cyclic voltammetry measurements of the catalysts.

  12. Raman Spectroscopy of the Reaction of Thin Films of Solid-State Benzene with Vapor-Deposited Ag, Mg, and Al

    SciTech Connect (OSTI)

    Schalnat, Matthew C. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Chemistry and Biochemistry; Hawkridge, Adam M. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Chemistry and Biochemistry; Pemberton, Jeanne E. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Chemistry and Biochemistry

    2011-07-21T23:59:59.000Z

    Thin films of solid-state benzene at 30 K were reacted with small quantities of vapor-deposited Ag, Mg, and Al under ultrahigh vacuum, and products were monitored using surface Raman spectroscopy. Although Ag and Mg produce small amounts of metal–benzene adduct products, the resulting Raman spectra are dominated by surface enhancement of the normal benzene modes from metallic nanoparticles suggesting rapid Ag or Mg metallization of the film. In contrast, large quantities of Al adduct products are observed. Vibrational modes of the products in all three systems suggest adducts that are formed through a pathway initiated by an electron transfer reaction. The difference in reactivity between these metals is ascribed to differences in ionization potential of the metal atoms; ionization potential values for Ag and Mg are similar but larger than that for Al. These studies demonstrate the importance of atomic parameters, such as ionization potential, in solid-state metal–organic reaction chemistry.

  13. Correlative analysis of the in situ changes of carrier decay and proton induced photoluminescence characteristics in chemical vapor deposition grown GaN

    SciTech Connect (OSTI)

    Gaubas, E., E-mail: eugenijus.gaubas@ff.vu.lt; Ceponis, T.; Jasiunas, A.; Meskauskaite, D.; Pavlov, J.; Tekorius, A.; Vaitkus, J. [Vilnius University, Institute of Applied Research, Vilnius LT-10222 (Lithuania); Kovalevskij, V.; Remeikis, V. [Centre for Physical Sciences and Technology, Vilnius LT-02300 (Lithuania)

    2014-02-10T23:59:59.000Z

    In order to evaluate carrier densities created by 1.6?MeV protons and to trace radiation damage of the 2.5??m thick GaN epi-layers grown by metalorganic chemical vapor deposition technique, a correlation between the photoconductivity transients and the steady-state photoluminescence spectra have been examined. Comparison of luminescence spectra induced by proton beam and by laser pulse enabled us to evaluate the efficiency of a single proton generation being of 1?×?10{sup 7}?cm{sup ?3} per 1.6?MeV proton and 40 carrier pairs per micrometer of layer depth. This result indicates that GaN layers can be an efficient material for detection of particle flows. It has been demonstrated that GaN material can also be a rather efficient scintillating material within several wavelength ranges.

  14. Microwave Plasma Chemical Vapor Deposition of Nano-Structured Sn/C Composite Thin-Film Anodes for Li-ion Batteries

    SciTech Connect (OSTI)

    Stevenson, Cynthia; Marcinek, M.; Hardwick, L.J.; Richardson, T.J.; Song, X.; Kostecki, R.

    2008-02-01T23:59:59.000Z

    In this paper we report results of a novel synthesis method of thin-film composite Sn/C anodes for lithium batteries. Thin layers of graphitic carbon decorated with uniformly distributed Sn nanoparticles were synthesized from a solid organic precursor Sn(IV) tert-butoxide by a one step microwave plasma chemical vapor deposition (MPCVD). The thin-film Sn/C electrodes were electrochemically tested in lithium half cells and produced a reversible capacity of 440 and 297 mAhg{sup -1} at C/25 and 5C discharge rates, respectively. A long term cycling of the Sn/C nanocomposite anodes showed 40% capacity loss after 500 cycles at 1C rate.

  15. A Phase Diagram of Low Temperature Epitaxial Silicon Grown by Hot-wire Chemical Vapor Deposition for Photovoltaic Devices

    E-Print Network [OSTI]

    Atwater, Harry

    for Photovoltaic Devices Christine Esber Richardson, Brendan M. Kayes, Matthew J. Dicken, and Harry A. Atwater-grained templates is one strategy for the fast, low- temperature growth of large-grained films with hydrogen). Figure 1: Schematic of proposed photovoltaic device incorporating epitaxial Si growth on a large

  16. Catalyst proximity effects on the growth rate of Si nanowires S. T. Boles,1,a

    E-Print Network [OSTI]

    and a silane precursor in a cold-wall chemical vapor deposition CVD system, where the precursor decomposition and experimental design, we have identified a fundamental aspect of growth of Si nanowires using the VLS mechanism

  17. MOCVD growth of In GaP-based heterostructures for light emitting devices

    E-Print Network [OSTI]

    McGill, Lisa Megan, 1975-

    2004-01-01T23:59:59.000Z

    In this work, we examine fundamental materials processes in the growth of indium gallium phosphide (InGaP) via metalorganic chemical vapor deposition (MOCVD). In particular, we realize improvements in the epitaxial integration ...

  18. Strain effects and microstructural evolution in Ge-Si system materials prepared by ion implantation and by ultrahigh vacuum chemical vapor deposition

    SciTech Connect (OSTI)

    Tu Hailing; Xiao Qinghua; Ma Tongda [General Research Institute for Non-ferrous Metals, No. 2, Xinjiekouwai Street, Beijing 100088 (China)

    2007-11-15T23:59:59.000Z

    Appropriately utilizing some microstructures may be very helpful to acquire desirable Ge-Si system materials. In this work, the Ge-Si system materials have been prepared either by ion implantation or ultrahigh vacuum chemical vapor deposition (UHVCVD). The interesting microstructures including half-loop dislocations, SiGe nanoclusters, and dislocation dipoles have been found in these two kinds of Ge-Si system materials. It is demonstrated that the evident surface strain state and adequate surface layer quality have been realized by employing these microstructures. Compared with the dipole dislocations in the Ge-Si systems deposited by UHVCVD on the compliant silicon on insulator, the half-loop dislocations and the SiGe nanoclusters induced by Ge ion implantation and subsequent annealing can relax the SiGe layer more effectively and lead to relatively large strain in the surface silicon. It may provide some new approaches to the control of misfit strains for fabricating desirable Ge-Si system materials.

  19. Effect of buffer layer growth temperature on epitaxial GaN films deposited by magnetron sputtering

    SciTech Connect (OSTI)

    Mohanta, P.; Singh, D.; Kumar, R.; Ganguli, T.; Srinivasa, R. S.; Major, S. S. [Center For Research in Nano-Technology and Science (India); Semiconductor Laser Section, RRCAT, Indore-452013 (India); Department of Metallurgical Engineering and Materials Science (India); Department of Physics, Indian Institute of Technology Bombay, Mumbai - 400076 (India)

    2012-06-05T23:59:59.000Z

    Epitaxial GaN films were deposited by reactive sputtering of a GaAs target in 100 % nitrogen at 700 deg. C on ZnO buffer layers grown at different substrate temperatures over sapphire substrates. High resolution X-ray diffraction measurements and the corresponding analysis show that the growth temperature of buffer layers significantly affects the micro-structural parameters of GaN epilayer, such as lateral coherence length, tilt and twist, while the vertical coherence length remains unaffected. The optimum substrate temperature for buffer layer growth has been found to be 300 deg. C. High epitaxial quality GaN film grown on such a buffer layer exhibited micro strain of 1.8x10{sup -4} along with screw and edge type dislocation densities of 7.87x10{sup 9} and 1.16x10{sup 11}, respectively.

  20. ENHANCED GROWTH RATE AND SILANE UTILIZATION IN AMORPHOUS SILICON AND NANOCRYSTALLINE-SILICON SOLAR CELL DEPOSITION VIA GAS PHASE ADDITIVES

    SciTech Connect (OSTI)

    Ridgeway, R.G.; Hegedus, S.S.; Podraza, N.J.

    2012-08-31T23:59:59.000Z

    Air Products set out to investigate the impact of additives on the deposition rate of both ���µCSi and ���±Si-H films. One criterion for additives was that they could be used in conventional PECVD processing, which would require sufficient vapor pressure to deliver material to the process chamber at the required flow rates. The flow rate required would depend on the size of the substrate onto which silicon films were being deposited, potentially ranging from 200 mm diameter wafers to the 5.7 m2 glass substrates used in GEN 8.5 flat-panel display tools. In choosing higher-order silanes, both disilane and trisilane had sufficient vapor pressure to withdraw gas at the required flow rates of up to 120 sccm. This report presents results obtained from testing at Air Products�¢���� electronic technology laboratories, located in Allentown, PA, which focused on developing processes on a commercial IC reactor using silane and mixtures of silane plus additives. These processes were deployed to compare deposition rates and film properties with and without additives, with a goal of maximizing the deposition rate while maintaining or improving film properties.

  1. Mechanistic studies of the thermal decomposition of metal carbonyls on Ni(100) surfaces in connection with chemical vapor deposition processes

    SciTech Connect (OSTI)

    Xu, M.; Zaera, F. [Department of Chemistry, University of California, Riverside, California 92521 (United States)] [Department of Chemistry, University of California, Riverside, California 92521 (United States)

    1996-03-01T23:59:59.000Z

    The thermal decomposition of Fe(CO){sub 5}, Cr(CO){sub 6}, Mo(CO){sub 6}, and W(CO){sub 6} on Ni(100) surfaces and under ultrahigh vacuum conditions was studied by using temperature programmed desorption and x-ray photoelectron spectroscopies. The initial adsorption of those metal carbonyls is mostly molecular at low temperatures, but complete decarbonylation to the naked metal takes place in all cases upon thermal activation. Experiments with coadsorbed isotopically labeled {sup 13}CO provided indirect evidence for a stepwise mechanism for Fe(CO){sub 5} which may include the formation of tetra- and tricarbonyl intermediates on the surface. For Cr(CO){sub 6}, Mo(CO){sub 6}, and W(CO){sub 6}, on the other hand, complete decomposition occurs in a narrow range of temperature, and no intermediate could be isolated on the surface. The deposition of metal films via metal carbonyl activation was studied under steady state conditions as well. Continuous deposition was seen at substrate temperatures as low as 300 K, but the grown films were found to incorporate both carbon and oxygen under most conditions tested and to change their morphology depending on the substrate temperature during deposition. {copyright} {ital 1996 American Vacuum Society}

  2. Synthesis of carbon nanotubes on diamond-like carbon by the hot filament plasma-enhanced chemical vapor deposition method

    E-Print Network [OSTI]

    Hong, Byungyou

    , scanning probes, nanoscale electronic devices, hydrogen storage, chemical sensors, and composite., 1995). These properties make CNTs good candidates for many applications such as field emission devices on a nanostructured transition metal catalyst such as Co, Ni, or Fe. The growth mechanisms of CNTs are divided

  3. Wear Mechanism of Chemical Vapor Deposition (CVD) Carbide Insert in Orthogonal Cutting Ti-6Al-4V ELI at High Cutting Speed

    SciTech Connect (OSTI)

    Gusri, A. I.; Che Hassan, C. H.; Jaharah, A. G. [Mechanical and Material Engineering Department, Universiti Kebangsaan Malaysia, Bangi 43600 (Malaysia)

    2011-01-17T23:59:59.000Z

    The performance of Chemical Vapor Deposition (CVD) carbide insert with ISO designation of CCMT 12 04 04 LF, when turning titanium alloys was investigated. There were four layers of coating materials for this insert i.e.TiN-Al2O3-TiCN-TiN. The insert performance was evaluated based on the insert's edge resistant towards the machining parameters used at high cutting speed range of machining Ti-6Al-4V ELI. Detailed study on the wear mechanism at the cutting edge of CVD carbide tools was carried out at cutting speed of 55-95 m/min, feed rate of 0.15-0.35 mm/rev and depth of cut of 0.10-0.20 mm. Wear mechanisms such as abrasive and adhesive were observed on the flank face. Crater wear due to diffusion was also observed on the rake race. The abrasive wear occurred more at nose radius and the fracture on tool were found at the feed rate of 0.35 mm/rev and the depth of cut of 0.20 mm. The adhesion wear takes place after the removal of the coating or coating delaminating. Therefore, adhesion or welding of titanium alloy onto the flank and rake faces demonstrates a strong bond at the workpiece-tool interface.

  4. Effects of arrival rate and gas pressure on the chemical bonding and composition in titanium nitride films prepared on Si(100) substrates by ion beam and vapor deposition

    SciTech Connect (OSTI)

    Matsuoka, M.; Isotani, S.; Mittani, J.C.R.; Chubaci, J.F.D.; Ogata, K.; Kuratani, N. [Institute of Physics, University of Sao Paulo, C. P. 66318, 05315-970, Sao Paolo, SP (Brazil); Nissin Electric Company, Ltd., 47, Umezu-Takase-cho, Ukyo-ku, Kyota 615-8686 (Japan)

    2005-01-01T23:59:59.000Z

    Thin titanium nitride films were prepared at room temperature by titanium metal vapor deposition on silicon substrates with simultaneous irradiation by a 2 keV nitrogen ion beam. Arrival rate ratios, ARR(N/Ti), defined as the ratio of the flux of incident atomic nitrogen particles in the ion beam relative to the flux of titanium atoms transported to the substrate, ranged from 0.17 to 2.5. The gas pressure in the vacuum chamber was maintained at 1.3x10{sup -3} or 6.7x10{sup -3} Pa during the deposition and irradiation process. Analyses of Ti 2p x-ray photoelectron spectroscopy spectra indicated the presence of metal Ti{sup 0}, nitride TiN, oxide TiO{sub 2}, oxynitride TiN{sub x}O{sub y}, and carbide TiC phases. The Ti{sup 0} phase was observed exclusively and predominantly in the films prepared at 1.3x10{sup -3} Pa and ARR(N/Ti)=0.17, 0.21, and 0.28, and the TiN phase is major in the others, as confirmed by the x-ray diffractometry analyses. The chemical composition ratio N/Ti in the films prepared at 1.3x10{sup -3} Pa increased linearly with increasing ARR(N/Ti) up to ARR(N/Ti)=0.42 and tended to be constant with further increase in ARR(N/Ti), while this ratio in the films prepared at 6.7x10{sup -3} Pa was almost constant independently of ARR(N/Ti), similar to the constant value observed at 1.3x10{sup -3} Pa and higher ARR(N/Ti). This dependence may be understood by comparison with the flux of evaporated titanium atoms, the flux of nitrogen in the beam, and the impingement rate of nitrogen gas in the vacuum chamber, evaluated through the kinetic theory of gases. On the other hand, titanium is known to be one of the chemically active materials which form stable compounds with gases by chemisorption, this fact leading to considerable incorporation of contaminant oxygen and carbon in the depositing titanium film.

  5. Gas-phase transport of WF6 through annular nanopipes in TiN during chemical vapor deposition of W on TiN/Ti/SiO2 structures for integrated

    E-Print Network [OSTI]

    Allen, Leslie H.

    Gas-phase transport of WF6 through annular nanopipes in TiN during chemical vapor deposition of W through the 106-nm-thick TiN film. W piles up at the TiN/Ti interface, while F rapidly saturates the TiN-sectional and scanning transmission electron microscopy analyses demonstrate that WF6 penetrates into the TiN layer

  6. Reducing dislocations in semiconductors utilizing repeated thermal cycling during multistage epitaxial growth

    DOE Patents [OSTI]

    Fan, John C. C. (Chestnut Hill, MA); Tsaur, Bor-Yeu (Arlington, MA); Gale, Ronald P. (Bedford, MA); Davis, Frances M. (Framingham, MA)

    1986-12-30T23:59:59.000Z

    Dislocation densities are reduced in growing semiconductors from the vapor phase by employing a technique of interrupting growth, cooling the layer so far deposited, and then repeating the process until a high quality active top layer is achieved. The method of interrupted growth, coupled with thermal cycling, permits dislocations to be trapped in the initial stages of epitaxial growth.

  7. Reducing dislocations in semiconductors utilizing repeated thermal cycling during multistage epitaxial growth

    DOE Patents [OSTI]

    Fan, John C. C. (Chestnut Hill, MA); Tsaur, Bor-Yeu (Arlington, MA); Gale, Ronald P. (Bedford, MA); Davis, Frances M. (Framingham, MA)

    1992-02-25T23:59:59.000Z

    Dislocation densities are reduced in growing semiconductors from the vapor phase by employing a technique of interrupting growth, cooling the layer so far deposited, and then repeating the process until a high quality active top layer is achieved. The method of interrupted growth, coupled with thermal cycling, permits dislocations to be trapped in the initial stages of epitaxial growth.

  8. SPIN (Version 3. 83): A Fortran program for modeling one-dimensional rotating-disk/stagnation-flow chemical vapor deposition reactors

    SciTech Connect (OSTI)

    Coltrin, M.E. (Sandia National Labs., Albuquerque, NM (United States)); Kee, R.J.; Evans, G.H.; Meeks, E.; Rupley, F.M.; Grcar, J.F. (Sandia National Labs., Livermore, CA (United States))

    1991-08-01T23:59:59.000Z

    In rotating-disk reactor a heated substrate spins (at typical speeds of 1000 rpm or more) in an enclosure through which the reactants flow. The rotating disk geometry has the important property that in certain operating regimes{sup 1} the species and temperature gradients normal to the disk are equal everywhere on the disk. Thus, such a configuration has great potential for highly uniform chemical vapor deposition (CVD),{sup 2--5} and indeed commercial rotating-disk CVD reactors are now available. In certain operating regimes, the equations describing the complex three-dimensional spiral fluid motion can be solved by a separation-of-variables transformation{sup 5,6} that reduces the equations to a system of ordinary differential equations. Strictly speaking, the transformation is only valid for an unconfined infinite-radius disk and buoyancy-free flow. Furthermore, only some boundary conditions are consistent with the transformation (e.g., temperature, gas-phase composition, and approach velocity all specified to be independent of radius at some distances above the disk). Fortunately, however, the transformed equations will provide a very good practical approximation to the flow in a finite-radius reactor over a large fraction of the disk (up to {approximately}90% of the disk radius) when the reactor operating parameters are properly chosen, i.e, high rotation rates. In the limit of zero rotation rate, the rotating disk flow reduces to a stagnation-point flow, for which a similar separation-of-variables transformation is also available. Such flow configurations ( pedestal reactors'') also find use in CVD reactors. In this report we describe a model formulation and mathematical analysis of rotating-disk and stagnation-point CVD reactors. Then we apply the analysis to a compute code called SPIN and describe its implementation and use. 31 refs., 4 figs.

  9. Organometallic vapor-phase homoepitaxy of gallium arsenide assisted by a downstream hydrogen afterglow plasma in the growth region

    E-Print Network [OSTI]

    Collins, George J.

    Organometallic vapor-phase homoepitaxy of gallium arsenide assisted by a downstream hydrogen 1991; accepted for publication 3 April 1992) hz situ generated arsenic hydrides are reacted downstream with trimethylgallium (TMGa), both in the presence of and in the absence of a downstream hydrogen afterglow plasma. The

  10. Ion beam assisted deposition of thermal barrier coatings

    DOE Patents [OSTI]

    Youchison, Dennis L. (Albuquerque, NM); McDonald, Jimmie M. (Albuquerque, NM); Lutz, Thomas J. (Albuquerque, NM); Gallis, Michail A. (Albuquerque, NM)

    2010-11-23T23:59:59.000Z

    Methods and apparatus for depositing thermal barrier coatings on gas turbine blades and vanes using Electron Beam Physical Vapor Deposition (EBPVD) combined with Ion Beam Assisted Deposition (IBAD).

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

    SciTech Connect (OSTI)

    Van Bui, Hao, E-mail: H.VanBui@utwente.nl; Wiggers, Frank B.; Gupta, Anubha; Nguyen, Minh D.; Aarnink, Antonius A. I.; Jong, Michel P. de; Kovalgin, Alexey Y., E-mail: A.Y.Kovalgin@utwente.nl [MESA Institute for Nanotechnology, University of Twente, P. O. Box 217, 7500 AE Enschede (Netherlands)

    2015-01-01T23:59:59.000Z

    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.

  12. Growth optimization and structural analysis for ferromagnetic Mn-doped ZnO layers deposited by radio frequency magnetron sputtering

    SciTech Connect (OSTI)

    Abouzaid, M.; Ruterana, P.; Liu, C.; Morkoc, H. [SIFCOM UMR 6176 CNRS-ENSICAEN, 6 Boulevard du Marechal Juin, 14050 Caen Cedex (France); Department of Electrical Engineering, Virginia Commonwealth University, Richmond Virginia 23284 (United States)

    2006-06-01T23:59:59.000Z

    The effect of the deposition temperature on the crystalline quality of (Zn,Mn)O is investigated in thin films prepared by radio frequency magnetron sputtering on c-plane sapphire and GaN substrates. The layers are made of a 0.5 {mu}m Mn-doped layer towards the surface on top of a 150 nm pure ZnO buffer. Depending on the deposition temperature, the layers can exhibit a columnar structure; the adjacent domains are rotated from one another by 90 deg. , putting [1010] and [1120] directions face to face. At high Mn concentration the columnar structure is blurred by the formation of Mn rich precipitates. Only one variety of domains is observed at an optimal deposition temperature of 500 deg. C: they are slightly rotated around the [0001] axis (mosaic growth) and bounded by threading dislocations.

  13. Growth direction of oblique angle electron beam deposited silicon monoxide thin films identified by optical second-harmonic generation

    SciTech Connect (OSTI)

    Vejling Andersen, Søren; Lund Trolle, Mads; Pedersen, Kjeld [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg Øst (Denmark)] [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg Øst (Denmark)

    2013-12-02T23:59:59.000Z

    Oblique angle deposited (OAD) silicon monoxide (SiO) thin films forming tilted columnar structures have been characterized by second-harmonic generation. It was found that OAD SiO leads to a rotationally anisotropic second-harmonic response, depending on the optical angle of incidence. A model for the observed dependence of the second-harmonic signal on optical angle of incidence allows extraction of the growth direction of OAD films. The optically determined growth directions show convincing agreement with cross-sectional scanning electron microscopy images. In addition to a powerful characterization tool, these results demonstrate the possibilities for designing nonlinear optical devices through SiO OAD.

  14. "Fractal Growth Modeling of Electrochemical Deposition in Solid Freeform Fabrication," J. G. Zhou, Z. He and J. Guo, Proceedings of the Tenth Solid Freeform Fabrication Symposium, Austin, Texas, August, 1999.

    E-Print Network [OSTI]

    Zhou, Jack

    "Fractal Growth Modeling of Electrochemical Deposition in Solid Freeform Fabrication," J. G. Zhou, August, 1999. FRACTAL GROWTH MODELING OF ELECTROCHEMICAL DEPOSITION IN SOLID FREEFORM FABRICATION Jack G deposition among metal particles during ECLD-SFF is a fractal growth process. The fractal dimension

  15. Hybrid deposition of thin film solid oxide fuel cells and electrolyzers

    DOE Patents [OSTI]

    Jankowski, A.F.; Makowiecki, D.M.; Rambach, G.D.; Randich, E.

    1998-05-19T23:59:59.000Z

    The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated. 8 figs.

  16. Hybrid deposition of thin film solid oxide fuel cells and electrolyzers

    DOE Patents [OSTI]

    Jankowski, Alan F. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Rambach, Glenn D. (Livermore, CA); Randich, Erik (Endinboro, PA)

    1998-01-01T23:59:59.000Z

    The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated.

  17. Hybrid deposition of thin film solid oxide fuel cells and electrolyzers

    DOE Patents [OSTI]

    Jankowski, Alan F. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Rambach, Glenn D. (Livermore, CA); Randich, Erik (Endinboro, PA)

    1999-01-01T23:59:59.000Z

    The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated.

  18. Reactive Ballistic Deposition of Porous TiO2 Films: Growth and...

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

    high-surface area films of TiO2 are synthesized by reactive ballistic deposition of titanium metal in an oxygen ambient. Auger electron spectroscopy (AES) is used to investigate...

  19. Double-sided reel-to-reel metal-organic chemical vapor deposition system of YBa{sub 2}Cu{sub 3}O{sub 7-?} thin films

    SciTech Connect (OSTI)

    Zhang, Fei; Xiong, Jie, E-mail: jiexiong@uestc.edu.cn; Liu, Xin; Zhao, Ruipeng; Zhao, Xiaohui; Tao, Bowan; Li, Yanrong [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2014-07-01T23:59:59.000Z

    Two-micrometer thick YBa{sub 2}Cu{sub 3}O{sub 7-?} (YBCO) films have been successfully deposited on both sides of LaAlO{sub 3} single crystalline substrates by using a home-made reel-to-reel metal-organic chemical vapor deposition (MOCVD) system, which has two opposite symmetrical shower heads and a special-designed heater. This technique can simultaneously fabricate double-sided films with high deposition rate up to 500?nm/min, and lead to doubling current carrying capability of YBCO, especially for coated conductors (CCs). X-ray diffraction analysis showed that YBCO films were well crystallized and highly epitaxial with the full width at half maximum values of 0.2°???0.3° for the rocking curves of (005) YBCO and 1.0° for ?-scans of (103) YBCO. Scanning electron microscope revealed dense, crack-free, slightly rough surface with Ba-Cu-O precipitates. The films showed critical current density (J{sub c}, 77?K, 0?T) of about 1 MA/cm{sup 2}, and overall critical current of 400?A/cm, ascribed to the double-sided structure. Our results also demonstrated that the temperature and composition in the deposition zone were uniform, which made MOCVD preparation of low cost and high performance double-sided YBCO CCs more promising for industrialization.

  20. Towards engineered branch placement: Unreal™ match between vapour-liquid-solid glancing angle deposition nanowire growth and simulation

    SciTech Connect (OSTI)

    Taschuk, M. T.; Tucker, R. T.; LaForge, J. M.; Beaudry, A. L. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6H 2V4 (Canada); Kupsta, M. R. [NRC National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada); Brett, M. J. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6H 2V4 (Canada); NRC National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada)

    2013-12-28T23:59:59.000Z

    The vapour-liquid-solid glancing angle deposition (VLS-GLAD) process is capable of producing complex nanotree structures with control over azimuthal branch orientation and height. We have developed a thin film growth simulation including ballistic deposition, simplified surface diffusion, and droplet-mediated cubic crystal growth for the VLS-GLAD process using the Unreal{sup TM} Development Kit. The use of a commercial game engine has provided an interactive environment while allowing a custom physics implementation. Our simulation's output is verified against experimental data, including a volumetric film reconstruction produced using focused ion beam and scanning-electron microscopy (SEM), crystallographic texture, and morphological characteristics such as branch orientation. We achieve excellent morphological and texture agreement with experimental data, as well as qualitative agreement with SEM imagery. The simplified physics in our model reproduces the experimental films, indicating that the dominant role flux geometry plays in the VLS-GLAD competitive growth process responsible for azimuthally oriented branches and biaxial crystal texture evolution. The simulation's successful reproduction of experimental data indicates that it should have predictive power in designing novel VLS-GLAD structures.

  1. Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating

    E-Print Network [OSTI]

    Harrington, Jerry Y.

    Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating CHRISTOPHER M. HARTMAN AND JERRY Y. HARRINGTON Department of Meteorology, The Pennsylvania November 2004) ABSTRACT The effects of solar heating and infrared cooling on the vapor depositional growth

  2. In-situ deposition of high-k dielectrics on III-V compound semiconductor in MOCVD system

    E-Print Network [OSTI]

    Cheng, Cheng-Wei, Ph.D. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    In situ deposition of high-k materials to passivate the GaAs in metal organic chemical vapor deposition (MOCVD) system was well demonstrated. Both atomic layer deposition (ALD) and chemical vapor deposition (CVD) methods ...

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

    SciTech Connect (OSTI)

    Wang, Han; Fu, Kan [Department of Materials Science and Engineering, University of Connecticut, Storrs, Connecticut 06269. (United States)] [Department of Materials Science and Engineering, University of Connecticut, Storrs, Connecticut 06269. (United States)

    2013-11-15T23:59:59.000Z

    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.

  4. Non-equilibrium deposition of phase pure Cu{sub 2}O thin films at reduced growth temperature

    SciTech Connect (OSTI)

    Subramaniyan, Archana, E-mail: asubrama@mymail.mines.edu [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States); Perkins, John D.; Lany, Stephan; Stevanovic, Vladan; Ginley, David S.; Zakutayev, Andriy [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); O’Hayre, Ryan P. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States)

    2014-02-01T23:59:59.000Z

    Cuprous oxide (Cu{sub 2}O) is actively studied as a prototypical material for energy conversion and electronic applications. Here we reduce the growth temperature of phase pure Cu{sub 2}O thin films to 300?°C by intentionally controlling solely the kinetic parameter (total chamber pressure, P{sub tot}) at fixed thermodynamic condition (0.25 mTorr pO{sub 2}). A strong non-monotonic effect of P{sub tot} on Cu-O phase formation is found using high-throughput combinatorial-pulsed laser deposition. This discovery creates new opportunities for the growth of Cu{sub 2}O devices with low thermal budget and illustrates the importance of kinetic effects for the synthesis of metastable materials with useful properties.

  5. Nanowire-templated lateral epitaxial growth of non-polar group III nitrides

    DOE Patents [OSTI]

    Wang, George T. (Albuquerque, NM); Li, Qiming (Albuquerque, NM); Creighton, J. Randall (Albuquerque, NM)

    2010-03-02T23:59:59.000Z

    A method for growing high quality, nonpolar Group III nitrides using lateral growth from Group III nitride nanowires. The method of nanowire-templated lateral epitaxial growth (NTLEG) employs crystallographically aligned, substantially vertical Group III nitride nanowire arrays grown by metal-catalyzed metal-organic chemical vapor deposition (MOCVD) as templates for the lateral growth and coalescence of virtually crack-free Group III nitride films. This method requires no patterning or separate nitride growth step.

  6. assisted chemical vapor: Topics by E-print Network

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

    nanodiamonds (NDs) with 70-80 nm size via bead assisted sonic disintegration (BASD) of a polycrystalline chemical vapor deposition (CVD) film. The NDs display high crystalline...

  7. Room-temperature cw operation of InGaP/InGaAlP visible light laser diodes on GaAs substrates grown by metalorganic chemical vapor deposition

    SciTech Connect (OSTI)

    Ishikawa, M.; Ohba, Y.; Sugawara, H.; Yamamoto, M.; Nakanisi, T.

    1986-01-20T23:59:59.000Z

    Room-temperature cw operation for InGaP/InGaAlP double heterostructure (DH) laser diodes on GaAs substrates was achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapor deposition using methyl metalorganics. A lasing wavelength of 679 nm and a threshold current of 109 mA at 24C were obtained for an inner stripe structure laser diode with a 250- m-long and 7- m stripe geometry. The laser operated at up to 51C. The characteristic temperature T0 was 87 K at around room temperature. The lowest threshold current density, 5.0 kA/cmS, was obtained with a 20- m stripe width laser diode under room-temperature pulsed operation.

  8. Low trap states in in situ SiN{sub x}/AlN/GaN metal-insulator-semiconductor structures grown by metal-organic chemical vapor deposition

    SciTech Connect (OSTI)

    Lu, Xing; Ma, Jun; Jiang, Huaxing; Liu, Chao; Lau, Kei May, E-mail: eekmlau@ust.hk [Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2014-09-08T23:59:59.000Z

    We report the use of SiN{sub x} grown in situ by metal-organic chemical vapor deposition as the gate dielectric for AlN/GaN metal-insulator-semiconductor (MIS) structures. Two kinds of trap states with different time constants were identified and characterized. In particular, the SiN{sub x}/AlN interface exhibits remarkably low trap state densities in the range of 10{sup 11}–10{sup 12?}cm{sup ?2}eV{sup ?1}. Transmission electron microscopy and X-ray photoelectron spectroscopy analyses revealed that the in situ SiN{sub x} layer can provide excellent passivation without causing chemical degradation to the AlN surface. These results imply the great potential of in situ SiN{sub x} as an effective gate dielectric for AlN/GaN MIS devices.

  9. Chemical vapor infiltration using microwave energy

    DOE Patents [OSTI]

    Devlin, David J. (Los Alamos, NM); Currier, Robert P. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Barbero, Robert S. (Santa Cruz, NM)

    1993-01-01T23:59:59.000Z

    A method for producing reinforced ceramic composite articles by means of chemical vapor infiltration and deposition in which an inverted temperature gradient is utilized. Microwave energy is the source of heat for the process.

  10. Photoinitiated chemical vapor depostion [sic] : mechanism and applications

    E-Print Network [OSTI]

    Baxamusa, Salmaan Husain

    2009-01-01T23:59:59.000Z

    Photoinitiated chemical vapor deposition (piCVD) is developed as a simple, solventless, and rapid method for the deposition of swellable hydrogels and functional hydrogel copolymers. Mechanistic experiments show that piCVD ...

  11. Measurement and modeling of Ar/H2/CH4 arc jet discharge chemical vapor deposition reactors II: Modeling of the spatial dependence of expanded

    E-Print Network [OSTI]

    Bristol, University of

    and used to deposit thin films of polycrystalline diamond. This reactor has been the subject of many prior of micro- and nanocrystalline diamond and diamondlike carbon films. The model incorporates gas activation-containing radical species incident on the growing diamond surface C atoms and CH radicals within this reactor

  12. Organic-vapor-liquid-solid deposition with an impinging gas jet Daniel W. Shaw, Kevin Bufkin, Alexandr A. Baronov, Brad L. Johnson, and David L. Patrick

    E-Print Network [OSTI]

    Patrick, David L.

    -sputter deposition of high-indium-content n-AlInN thin film on p-Si(001) substrate for photovoltaic applications J-assisted processing AIP Advances 2, 032171 (2012) Degradation and passivation of CuInSe2 Appl. Phys. Lett. 101, 112108 been used in transistors, light emitting diodes, and photovoltaics;2 as chemical sensors;3

  13. The influence of ammonia on rapid-ther al low-pressure metalorganic chemical vapor deposited TIN, films from tetrakis (dimethylamido) titanium

    E-Print Network [OSTI]

    Florida, University of

    , films from tetrakis (dimethylamido) titanium precursor onto InP A. Katz, A. Feingold, S. Nakahara, and SP, using a combined reactive chemistry of ammonia (NH,) gas and tetrakis (dimethylamido) titanium (DMATi to the preview RT-LPMOCVD TN, film deposited using only the DMATi precursor. I. INTRODUCTION Titanium nitride

  14. Real-time process sensing and metrology in amorphous and selective area silicon plasma enhanced chemical vapor deposition using in situ

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Real-time process sensing and metrology in amorphous and selective area silicon plasma enhanced Materials Processing, North Carolina State University, Raleigh, North Carolina 27695 Received 11 July 1996 silicon deposition. The ability of mass spectrometry to observe process faults in real time is also

  15. Effect of reactor pressure on the electrical and structural properties of InN epilayers grown by high-pressure chemical vapor deposition

    E-Print Network [OSTI]

    Nabben, Reinhard

    Effect of reactor pressure on the electrical and structural properties of InN epilayers grown://avspublications.org/jvsta/about/rights_and_permissions #12;Effect of reactor pressure on the electrical and structural properties of InN epilayers grown-atmospheric reactor pressures (2.5­18.5 bar) on the electrical and structural properties of InN epilayers deposited

  16. Growth of GaN on SiC(0001) by Molecular Beam Epitaxy C. D. LEE (a), ASHUTOSH SAGAR (a), R. M. FEENSTRA

    E-Print Network [OSTI]

    Feenstra, Randall

    years as a substrate for both molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy of GaN of the substrate preparation and growth technique. Experimental GaN films of typically 1 mm thickness are deposited1 Growth of GaN on SiC(0001) by Molecular Beam Epitaxy C. D. LEE (a), ASHUTOSH SAGAR (a), R. M

  17. Laser Directed Growth of Carbon-Based Nanostructures by Plasmon Resonant

    E-Print Network [OSTI]

    Cronin, Steve

    Laser Directed Growth of Carbon-Based Nanostructures by Plasmon Resonant Chemical Vapor Deposition the strong plasmon resonance of gold nanoparticles in the catalytic decomposition of CO to grow various forms of carbonaceous materials. Irradiating gold nanoparticles in a CO environment at their plasmon resonant frequency

  18. Effects of oxygen on the growth characteristics of carbon nanotubes on conductive substrates

    E-Print Network [OSTI]

    Bonaparte, Ryan K

    2009-01-01T23:59:59.000Z

    The effects of oxygen on Fe-catalyzed carbon nanotube (CNT) growth on Ta substrates was studied. CNTs were grown on Fe thin-film catalysts deposited on silicon substrates via exposure to C?H? in a thermal chemical vapor ...

  19. Effects of phosphorus implantation and subsequent growth on diamond Euo Sik Choa,*, Cheon An Leea

    E-Print Network [OSTI]

    Lee, Jong Duk

    ]. Espe- cially, polycrystalline diamond films grown by microwave plasma chemical vapor deposition (MPCVD, and their fabrication is easy and economical. Polycrystalline diamond film has a rough surface and a lot of defectsEffects of phosphorus implantation and subsequent growth on diamond Euo Sik Choa,*, Cheon An Leea

  20. MOVPE growth of semipolar III-nitride semiconductors on CVD graphene Priti Gupta n

    E-Print Network [OSTI]

    Deshmukh, Mandar M.

    MOVPE growth of semipolar III-nitride semiconductors on CVD graphene Priti Gupta n , A.A. Rahman pressure metalorganic vapor phase epitaxy B1. Graphene B1. Nitrides B2. Semiconducting III­V materials a b on graphene grown by chemical vapour deposition. GaN, AlGaN alloys, and InN layers are grown using an Al

  1. Hidden features of the catalyst nanoparticles favorable for single-walled carbon nanotube growth

    E-Print Network [OSTI]

    Curtarolo, Stefano

    nanotube growth by using chemical vapor deposition synthesis augmented by an attached mass spectrometer MS,16 Fig. 1 a , a widely debated issue in the literature.7­10 Based on the cal- culated Fe­C liquidus lines to mention that in our studies we use methane gas. Unlike methane, the dehydrogenation reactions of other

  2. Reduced Order Based Compensator Control of Thin Film Growth in a CVD Reactor

    E-Print Network [OSTI]

    Reduced Order Based Compensator Control of Thin Film Growth in a CVD Reactor H.T. Banks and H chemical vapor deposition (CVD) reactors. An in­ tegral component of this research program is the design of the reactor so that control and sensing are a basic component of the optimal design e#orts for the reactor. We

  3. Reduced Order Based Compensator Control of Thin Film Growth in a CVD Reactor

    E-Print Network [OSTI]

    Reduced Order Based Compensator Control of Thin Film Growth in a CVD Reactor H.T. Banks and H chemical vapor deposition (CVD) reactors. An in- tegral component of this research program is the design of the reactor so that control and sensing are a basic component of the optimal design efforts for the reactor

  4. Fermi Level Control of Point Defects During Growth of Mg-Doped GaN

    E-Print Network [OSTI]

    Nabben, Reinhard

    Fermi Level Control of Point Defects During Growth of Mg-Doped GaN ZACHARY BRYAN,1,4 MARC HOFFMANN defects during metalorganic chem- ical vapor deposition (MOCVD) of Mg-doped GaN has been demonstrated of magnitude lower resistivity values compared with typical unan- nealed GaN:Mg samples. The PL spectra

  5. Analysis of calorimetric measurements of grain growth L. C. Chena) and F. Spaepen

    E-Print Network [OSTI]

    Spaepen, Frans A.

    solidification4 or vapor deposition,' or in some of the materials prepared by gas condensation and compaction,6Analysis of calorimetric measurements of grain growth L. C. Chena) and F. Spaepen Division. The Kissinger' analysis of the shift of the transformation peaks as a function of heating rate is perhaps

  6. Critical factor for epitaxial growth of cobalt-doped BaFe{sub 2}As{sub 2} films by pulsed laser deposition

    SciTech Connect (OSTI)

    Hiramatsu, Hidenori, E-mail: h-hirama@lucid.msl.titech.ac.jp; Kamiya, Toshio [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-1, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Sato, Hikaru [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-1, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Katase, Takayoshi [Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Hosono, Hideo [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-1, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan)

    2014-04-28T23:59:59.000Z

    We heteroepitaxially grew cobalt-doped BaFe{sub 2}As{sub 2} films on (La,Sr)(Al,Ta)O{sub 3} single-crystal substrates by pulsed laser deposition using four different wavelengths and investigated how the excitation wavelength and pulse energy affected growth. Using the tilting and twisting angles of X-ray diffraction rocking curves, we quantitatively analyzed the crystallinity of each film. We found that the optimal deposition rate, which could be tuned by pulse energy, was independent of laser wavelength. The high-quality film grown at the optimal pulse energy (i.e., the optimum deposition rate) exhibited high critical current density over 1 MA/cm{sup 2} irrespective of the laser wavelength.

  7. Harvard University Atomic Layer Deposition (ALD): An Enabler

    E-Print Network [OSTI]

    Deposition (CVD) One or more gases or vapors react to form a solid product Reaction started by heat mixing 2 vapors plasma Solid product can be a film particle nanowire nanotube precursor vapors byproduct vapors University Coatings on the Outside of Particles ALD AlN coating ZnS particles Used in electroluminescent back

  8. Control Mechanisms for the Growth of Isolated Vertically Aligned Carbon Nanofibers

    SciTech Connect (OSTI)

    Merkulov, Vladimir I [ORNL; Hensley, Dale K [ORNL; Melechko, Anatoli Vasilievich [ORNL; Guillorn, M. A. [Cornell University; Lowndes, Douglas H [ORNL; Simpson, Michael L [ORNL

    2002-01-01T23:59:59.000Z

    Isolated vertically aligned carbon nanofibers (VACNFs) have been grown using dc plasma-enhanced chemical vapor deposition, and the effects of the growth conditions on VACNF morphology and composition have been determined in substantial detail. The dependence of the growth rate, tip and base diameters, and chemical composition of isolated VACNFs on the growth parameters is described, including the effects of plasma power and gas mixture. Phenomenological models explaining the observed growth behavior are presented. The results indicate the importance of plasma control for the deterministic growth of isolated VACNFs, which are promising elements for the fabrication of practical nanoscale devices.

  9. Growth of tungsten oxide on carbon nanowalls templates

    SciTech Connect (OSTI)

    Wang, Hua, E-mail: wanghua@dlou.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023 (China); Su, Yan [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Chen, Shuo, E-mail: shuochen@dlut.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Quan, Xie [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-03-15T23:59:59.000Z

    Highlights: ? Tungsten oxide deposited on carbon nanowalls by hot filament chemical vapor deposition technique. ? This composite has two-dimensional uniform morphology with a crystalline structure of monoclinic tungsten trioxide. ? Surface photoelectric voltage measurements show that this product has photoresponse properties. - Abstract: In the present work we present a simple approach for coupling tungsten oxide with carbon nanowalls. The two-dimensional carbon nanowalls with open boundaries were grown using plasma enhanced hot filament chemical vapor deposition, and the subsequent tungsten oxide growth was performed in the same equipment by direct heating of a tungsten filament. The tungsten oxide coating is found to have uniform morphology with a crystalline structure of monoclinic tungsten trioxide. Surface photoelectric voltage measurements show that this product has photoresponse properties. The method of synthesis described here provides an operable route to the production of two-dimensional tungsten oxide nanocomposites.

  10. Direct Visualization of Initial SEI Morphology and Growth Kinetics During Lithium Deposition by in situ Electrochemical Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Sacci, Robert L.; Dudney, Nancy J.; More, Karren L.; Parent, Lucas R.; Arslan, Ilke; Browning, Nigel D.; Unocic, Raymond R.

    2013-12-20T23:59:59.000Z

    Deposition of Li is a major safety concern existing in Li-ion secondary batteries. Here we perform the first in situ high spatial resolution measurement coupled with real-time quantitative electrochemistry to characterize SEI formation on gold using a standard battery electrolyte. We demonstrate that a dendritic SEI forms prior to Li deposition and that it remains on the surface after Li electrodissolution.

  11. Metalorganic Chemical Vapor Deposition for Optoelectronic Devices

    E-Print Network [OSTI]

    Coleman, James J.

    ­1100 nm, visible InGaP and related compounds, and the column III nitrides for blue and ultraviolet la

  12. Quantum cascade laser investigations of CH{sub 4} and C{sub 2}H{sub 2} interconversion in hydrocarbon/H{sub 2} gas mixtures during microwave plasma enhanced chemical vapor deposition of diamond

    SciTech Connect (OSTI)

    Ma Jie; Cheesman, Andrew; Ashfold, Michael N. R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Hay, Kenneth G.; Wright, Stephen; Langford, Nigel; Duxbury, Geoffrey [Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Mankelevich, Yuri A. [Skobel'tsyn Institute of Nuclear Physics, Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation)

    2009-08-01T23:59:59.000Z

    CH{sub 4} and C{sub 2}H{sub 2} molecules (and their interconversion) in hydrocarbon/rare gas/H{sub 2} gas mixtures in a microwave reactor used for plasma enhanced diamond chemical vapor deposition (CVD) have been investigated by line-of-sight infrared absorption spectroscopy in the wavenumber range of 1276.5-1273.1 cm{sup -1} using a quantum cascade laser spectrometer. Parameters explored include process conditions [pressure, input power, source hydrocarbon, rare gas (Ar or Ne), input gas mixing ratio], height (z) above the substrate, and time (t) after addition of hydrocarbon to a pre-existing Ar/H{sub 2} plasma. The line integrated absorptions so obtained have been converted to species number densities by reference to the companion two-dimensional (r,z) modeling of the CVD reactor described in Mankelevich et al. [J. Appl. Phys. 104, 113304 (2008)]. The gas temperature distribution within the reactor ensures that the measured absorptions are dominated by CH{sub 4} and C{sub 2}H{sub 2} molecules in the cool periphery of the reactor. Nonetheless, the measurements prove to be of enormous value in testing, tensioning, and confirming the model predictions. Under standard process conditions, the study confirms that all hydrocarbon source gases investigated (methane, acetylene, ethane, propyne, propane, and butane) are converted into a mixture dominated by CH{sub 4} and C{sub 2}H{sub 2}. The interconversion between these two species is highly dependent on the local gas temperature and the H atom number density, and thus on position within the reactor. CH{sub 4}->C{sub 2}H{sub 2} conversion occurs most efficiently in an annular shell around the central plasma (characterized by 1400CH{sub 4} is favored in the more distant regions where T{sub gas}<1400 K. Analysis of the multistep interconversion mechanism reveals substantial net consumption of H atoms accompanying the CH{sub 4}->C{sub 2}H{sub 2} conversion, whereas the reverse C{sub 2}H{sub 2}->CH{sub 4} process only requires H atoms to drive the reactions; H atoms are not consumed by the overall conversion.

  13. atmospheric dry deposition: Topics by E-print Network

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

    water vapor, and we confirm such predictions in a numerical model. There have been a number 38 Dual nitrate isotopes in dry deposition: Utility for partitioning NOx source...

  14. Growth mechanism of graphene on platinum: Surface catalysis and carbon segregation

    SciTech Connect (OSTI)

    Sun, Jie, E-mail: jie.sun@chalmers.se; Lindvall, Niclas; Yurgens, August [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Nam, Youngwoo [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Cole, Matthew T. [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, CB3 0FA Cambridge (United Kingdom); Teo, Kenneth B. K. [AIXTRON Nanoinstruments Ltd., Swavesey, CB24 4FQ Cambridge (United Kingdom); Woo Park, Yung [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-04-14T23:59:59.000Z

    A model of the graphene growth mechanism of chemical vapor deposition on platinum is proposed and verified by experiments. Surface catalysis and carbon segregation occur, respectively, at high and low temperatures in the process, representing the so-called balance and segregation regimes. Catalysis leads to self-limiting formation of large area monolayer graphene, whereas segregation results in multilayers, which evidently “grow from below.” By controlling kinetic factors, dominantly monolayer graphene whose high quality has been confirmed by quantum Hall measurement can be deposited on platinum with hydrogen-rich environment, quench cooling, tiny but continuous methane flow and about 1000?°C growth temperature.

  15. Development of chemical vapor composites, CVC materials. Final report

    SciTech Connect (OSTI)

    NONE

    1998-10-05T23:59:59.000Z

    Industry has a critical need for high-temperature operable ceramic composites that are strong, non-brittle, light weight, and corrosion resistant. Improvements in energy efficiency, reduced emissions and increased productivity can be achieved in many industrial processes with ceramic composites if the reaction temperature and pressure are increased. Ceramic composites offer the potential to meet these material requirements in a variety of industrial applications. However, their use is often restricted by high cost. The Chemical Vapor composite, CVC, process can reduce the high costs and multiple fabrication steps presently required for ceramic fabrication. CVC deposition has the potential to eliminate many difficult processing problems and greatly increase fabrication rates for composites. With CVC, the manufacturing process can control the composites` density, microstructure and composition during growth. The CVC process: can grow or deposit material 100 times faster than conventional techniques; does not require an expensive woven preform to infiltrate; can use high modulus fibers that cannot be woven into a preform; can deposit composites to tolerances of less than 0.025 mm on one surface without further machining.

  16. Growth strategies to control tapering in Ge nanowires

    SciTech Connect (OSTI)

    Periwal, P.; Baron, T., E-mail: thierry.baron@cea.fr; Salem, B.; Bassani, F. [Laboratoire des Technologies de la Microelectronique (LTM), UMR 5129 CNRS-UJF, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble (France); Gentile, P. [SiNaPs Laboratory SP2M, UMR-E, CEA/UJF-Grenoble 1, INAC, 38054 Grenoble (France)

    2014-04-01T23:59:59.000Z

    We report the effect of PH{sub 3} on the morphology of Au catalyzed Ge nanowires (NWs). Ge NWs were grown on Si (111) substrate at 400?°C in the presence of PH{sub 3}, using vapor-liquid-solid method by chemical vapor deposition. We show that high PH{sub 3}/GeH{sub 4} ratio causes passivation at NW surface. At high PH{sub 3} concentration phosphorous atoms attach itself on NW surface and form a self-protection coating that prevents conformal growth and leads to taper free nanostructures. However, in case of low PH{sub 3} flux the combination of axial and radial growth mechanism occurs resulting in conical structure. We have also investigated axial PH{sub 3}-intrinsic junctions in Ge NWs. The unusual NW shape is attributed to a combination of catalyzed, uncatalyzed and diffusion induced growth.

  17. Direct Visualization of Dendrite Nucleation and Growth Kinetics during Lithium Deposition with in situ Electrochemical Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Sacci, Robert L [ORNL; Dudney, Nancy J [ORNL; More, Karren Leslie [ORNL; Browning, Nigel [Pacific Northwest National Laboratory (PNNL); Unocic, Raymond R [ORNL

    2014-01-01T23:59:59.000Z

    Formation of Li dendrites is a major safety concern existing in Li-ion secondary batteries. A quantitative electrochemistry method to investigate the dendrite nucleation and growth mechanisms at high spatial is presented. Cyclic voltammetry, in combination with in situ electrochemical transmission electron microscopy (in situ ec-TEM), was used to quantitatively characterize dendrite nucleation and growth mechanisms from a Au working electrode and within a 1.2M LiPF6 EC:DMC electrolyte.

  18. In situ X-ray investigation of changing barrier growth temperatures on InGaN single quantum wells in metal-organic vapor phase epitaxy

    SciTech Connect (OSTI)

    Ju, Guangxu, E-mail: g-ju@nuee.nagoya-u.ac.jp; Honda, Yoshio [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Tabuchi, Masao [Synchrotron Radiation Research Centre, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Takeda, Yoshikazu [Synchrotron Radiation Center, Aichi Science and Technology Foundation, Seto, Aichi 489-0965 (Japan); Nagoya Industrial Science Research Institute, Nagoya, Aichi 464-0819 (Japan); Amano, Hiroshi [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Akasaki Research Center, Nagoya University, Aichi 464-8603 (Japan)

    2014-03-07T23:59:59.000Z

    The effects of GaN quantum barriers with changing growth temperatures on the interfacial characteristics of GaN/InGaN single quantum well (SQW) grown on GaN templates by metalorganic vapour phase epitaxy were in situ investigated by X-ray crystal truncation rod (CTR) scattering and X-ray reflectivity measurements at growth temperature using a laboratory level X-ray diffractometer. Comparing the curve-fitting results of X-ray CTR scattering spectra obtained at growth temperature with that at room temperature, the In{sub x}Ga{sub 1-x}N with indium composition less than 0.11 was stabile of the indium distribution at the interface during the whole growth processes. By using several monolayers thickness GaN capping layer to protect the InGaN well layer within temperature-ramping process, the interfacial structure of the GaN/InGaN SQW was drastically improved on the basis of the curve-fitting results of X-ray CTR scattering spectra, and the narrow full width at half-maximum and strong luminous intensity were observed in room temperature photoluminescence spectra.

  19. Growth mechanisms of carbon nanotrees with branched carbon nanofibers synthesized by plasma-enhanced chemical vapour deposition

    E-Print Network [OSTI]

    Boyer, Edmond

    be interesting for future applications in nanoelectronic devices and also composite materials. hal-008807221 Growth mechanisms of carbon nanotrees with branched carbon nanofibers synthesized by plasma , Didier Pribat*, 3 1 State Key Laboratory for Advanced Metals and Materials, University of Science

  20. Structures and Energetics of Some Potential Intermediates in Titanium Nitride Chemical Vapor Deposition: TiClm(NH2)n, TiClm(NH2)nNH, and TiClm(NH2)nN. An ab Initio

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Structures and Energetics of Some Potential Intermediates in Titanium Nitride Chemical Vapor with these basis sets augmented by multiple sets of polarization and diffuse functions using the B3LYP optimized geometries. Bond dissociation energies, heats of atomization, heats of formation, and entropies have been

  1. IPAP Conference Series 1: IWN2000, Nov., 2000 1 Morphology Dependent Growth Kinetics of Ga-polar GaN(0001)

    E-Print Network [OSTI]

    Cohen, Philip I.

    IPAP Conference Series 1: IWN2000, Nov., 2000 1 Morphology Dependent Growth Kinetics of Ga-polar GaN, cohen@ece.umn.edu GaN grown on Ga polar GaN templates prepared by metal-organic vapor deposition shows to equilibrium models of the growth. The results indicate that Ga-polar GaN(0001) has a step energy of the order

  2. A Minimal Model for Large-scale Epitaxial Growth Kinetics of Graphene

    E-Print Network [OSTI]

    Jiang, Huijun

    2015-01-01T23:59:59.000Z

    Epitaxial growth via chemical vapor deposition is considered to be the most promising way towards synthesizing large area graphene with high quality. However, it remains a big theoretical challenge to reveal growth kinetics with atomically energetic and large-scale spatial information included. Here, we propose a minimal kinetic Monte Carlo model to address such an issue on an active catalyst surface with graphene/substrate lattice mismatch, which facilitates us to perform large scale simulations of the growth kinetics over two dimensional surface with growth fronts of complex shapes. A geometry-determined large-scale growth mechanism is revealed, where the rate-dominating event is found to be $C_{1}$-attachment for concave growth front segments and $C_{5}$-attachment for others. This growth mechanism leads to an interesting time-resolved growth behavior which is well consistent with that observed in a recent scanning tunneling microscopy experiment.

  3. Vapor spill monitoring method

    DOE Patents [OSTI]

    Bianchini, Gregory M. (Livermore, CA); McRae, Thomas G. (Livermore, CA)

    1985-01-01T23:59:59.000Z

    Method for continuous sampling of liquified natural gas effluent from a spill pipe, vaporizing the cold liquified natural gas, and feeding the vaporized gas into an infrared detector to measure the gas composition. The apparatus utilizes a probe having an inner channel for receiving samples of liquified natural gas and a surrounding water jacket through which warm water is flowed to flash vaporize the liquified natural gas.

  4. Vapor scavenging by atmospheric aerosol particles

    SciTech Connect (OSTI)

    Andrews, E.

    1996-05-01T23:59:59.000Z

    Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

  5. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOE Patents [OSTI]

    Schmitt, III, Jerome J. (New Haven, CT); Halpern, Bret L. (Bethany, CT)

    1993-01-01T23:59:59.000Z

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.

  6. In-situ spectroscopic ellipsometry study of copper selective-area atomic layer deposition on palladium

    SciTech Connect (OSTI)

    Jiang, Xiaoqiang; Wang, Han; Qi, Jie; Willis, Brian G., E-mail: bgwillis@engr.uconn.edu [Department of Chemical and Biomolecular Engineering University of Connecticut, Storrs, Connecticut 06269-3222 (United States)

    2014-07-01T23:59:59.000Z

    Selective area copper atomic layer deposition on palladium seed layers has been investigated with in-situ real-time spectroscopic ellipsometry to probe the adsorption/desorption and reaction characteristics of individual deposition cycles. The reactants are copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) vapor and hydrogen gas. Self-limiting atomic layer deposition was observed in the temperature range of 135–230?°C in a low pressure reactor. Under optimal conditions, growth occurs selectively on palladium and not on silicon dioxide or silicon nitride layers. Based on in-situ ellipsometry data and supporting experiments, a new mechanism for growth is proposed. In the proposed mechanism, precursor adsorption is reversible, and dissociatively adsorbed hydrogen are the stable surface intermediates between growth cycles. The mechanism is enabled by continuous diffusion of palladium from the seed layer into the deposited copper film and strong H* binding to palladium sites. Less intermixing can be obtained at low growth temperatures and short cycle times by minimizing Cu/Pd inter-diffusion.

  7. Atomic layer deposition of molybdenum oxide using bis(tert-butylimido)bis(dimethylamido) molybdenum

    SciTech Connect (OSTI)

    Bertuch, Adam, E-mail: abertuch@ultratech.com; Sundaram, Ganesh [Ultratech/Cambridge NanoTech, 130 Turner Street, Waltham, Massachusetts 02453 (United States); Saly, Mark; Moser, Daniel; Kanjolia, Ravi [SAFC Hitech, 1429 Hilldale Avenue, Haverhill, Massachusetts 01832 (United States)

    2014-01-15T23:59:59.000Z

    Molybdenum trioxide films have been deposited using thermal atomic layer deposition techniques with bis(tert-butylimido)bis(dimethylamido)molybdenum. Films were deposited at temperatures from 100 to 300?°C using ozone as the oxidant for the process. The Mo precursor was evaluated for thermal stability and volatility using thermogravimetric analysis and static vapor pressure measurements. Film properties were evaluated with ellipsometry, x-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and secondary electron microscopy. The growth rate per cycle was determined to extend from 0.3 to 2.4?Å/cycle with <4% nonuniformity (1-sigma) with-in-wafer across a 150?mm wafer for the investigated temperature range.

  8. Effect of Electronic Excitation on Thin Film Growth

    SciTech Connect (OSTI)

    Elsayed-Ali, Hani E. [Old Dominion University

    2011-01-31T23:59:59.000Z

    The effect of nanosecond pulsed laser excitation on surface diffusion during growth of Ge on Si(100) at 250 degrees C was studied. In Situ reflection high-energy electron diffraction (RHEED) was used to measure the surface diffusion coefficient while ex situ atomic force microscopy (AFM) was used to probe the structure and morphology of the grown quantum dots. The results show that laser excitation of the substrate increases the surface diffusion during growth of Ge on Si(100), changes the growth morphology, improves crystalline structure of the grown quantum dots, and decreases their size distribution. A purely electronic mechanism of enhanced surface diffusion of the deposited Ge is proposed. Ge quantum dots were grown on Si(100)-(2x1) by pulsed laser deposition at various substrate temperatures using a femtosecond Ti:sapphire laser. In-situ reflection high-energy electron diffraction and ex-situ atomic force microscopy were used to analyze the fim structure and morphology. The morphology of germanium islands on silicon was studied at differect coverages. The results show that femtosecond pulsed laser depositon reduces the minimum temperature for epitaxial growth of Ge quantum dots to ~280 degrees C, which is 120 degrees C lower then previously observed in nanosecond pulsed laser deposition and more than 200 degrees C lower than that reported for molecular beam epitaxy and chemical vapor deposition.

  9. Epitaxial Growth and Characterization of Silicon Carbide Films

    SciTech Connect (OSTI)

    Dhanaraj,G.; Dudley, M.; Chen, Y.; Ragothamachar, B.; Wu, B.; Zhang, H.

    2006-01-01T23:59:59.000Z

    Silicon carbide (SiC) epitaxial layers have been grown in a chemical vapor deposition (CVD) system designed and fabricated in our laboratory. Silicon tetrachloride-propane as well as silane-propane were used as precursor gases. The hot zone was designed based on simulation by using numerical modeling. Growth rates up to 200 {mu}m could be achieved. A new growth-assisted hydrogen etching was developed to show the distribution of the micropipes present in the substrate. Higher growth rate was observed on off-axis (0 0 0 1) 4 H SiC compared to the on-axis (0 0 0 1) wafer and growth mechanism was explained.

  10. Instrument Series: Deposition and Microfabrication Sputter Deposition

    E-Print Network [OSTI]

    heating for attaining precise and repeatable growth conditions Substrate rotation ­ provides variable-speed offers operational flexibility, efficiency, and control, allowing a range of applications and materials and solid oxide fuel cells and solar cells for energy generation Microfabrication ­ deposition

  11. Plasma-enhanced atomic layer deposition of silicon dioxide films using plasma-activated triisopropylsilane as a precursor

    SciTech Connect (OSTI)

    Jeon, Ki-Moon [Vacuum Center, Division of Industrial Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340, South Korea and Department of Advanced Materials Engineering, Dae Jeon University, Daejeon 300-716 (Korea, Republic of); Shin, Jae-Su [Department of Advanced Materials Engineering, Dae Jeon University, Daejeon 300-716 (Korea, Republic of); Yun, Ju-Young [Vacuum Center, Division of Industrial Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340, South Korea and Department of Nano and Bio Surface Science, University of Science and Technology (UST), Daejeon 305-333 (Korea, Republic of); Jun Lee, Sang [Center of Nanomaterials Characterization, Division of Industrial Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340, South Korea and Department of Nano Science, University of Science and Technology (UST), Daejeon 305-333 (Korea, Republic of); Kang, Sang-Woo, E-mail: swkang@kriss.re.kr [Vacuum Center, Division of Industrial Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340, South Korea and Department of Advanced Device Technology, University of Science and Technology (UST), Daejeon 305-333 (Korea, Republic of)

    2014-05-15T23:59:59.000Z

    The plasma-enhanced atomic layer deposition (PEALD) process was developed as a growth technique of SiO{sub 2} thin films using a plasma-activated triisopropylsilane [TIPS, ((iPr){sub 3}SiH)] precursor. TIPS was activated by an argon plasma at the precursor injection stage of the process. Using the activated TIPS, it was possible to control the growth rate per cycle of the deposited films by adjusting the plasma ignition time. The PEALD technique allowed deposition of SiO{sub 2} films at temperatures as low as 50?°C without carbon impurities. In addition, films obtained with plasma ignition times of 3?s and 10?s had similar values of root-mean-square surface roughness. In order to evaluate the suitability of TIPS as a precursor for low-temperature deposition of SiO{sub 2} films, the vapor pressure of TIPS was measured. The thermal stability and the reactivity of the gas-phase TIPS with respect to water vapor were also investigated by analyzing the intensity changes of the C–H and Si–H peaks in the Fourier-transform infrared spectrum of TIPS.

  12. Effects of laser energy fluence on the onset and growth of the Rayleigh-Taylor instabilities and its influence on the topography of the Fe thin film grown in pulsed laser deposition facility

    SciTech Connect (OSTI)

    Mahmood, S. [National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore); Department of Physics, University of Karachi, Karachi 75270 (Pakistan); Rawat, R. S.; Wang, Y.; Lee, S.; Tan, T. L.; Springham, S. V.; Lee, P. [National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore); Zakaullah, M. [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan)

    2012-10-15T23:59:59.000Z

    The effect of laser energy fluence on the onset and growth of Rayleigh-Taylor (RT) instabilities in laser induced Fe plasma is investigated using time-resolved fast gated imaging. The snow plow and shock wave models are fitted to the experimental results and used to estimate the ablation parameters and the density of gas atoms that interact with the ablated species. It is observed that RT instability develops during the interface deceleration stage and grows for a considerable time for higher laser energy fluence. The effects of RT instabilities formation on the surface topography of the Fe thin films grown in pulsed laser deposition system are investigated (i) using different laser energy fluences for the same wavelength of laser radiation and (ii) using different laser wavelengths keeping the energy fluence fixed. It is concluded that the deposition achieved under turbulent condition leads to less smooth deposition surfaces with bigger sized particle agglomerates or network.

  13. Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

    SciTech Connect (OSTI)

    Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T.

    1994-10-01T23:59:59.000Z

    Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of uranium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed.

  14. Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

    SciTech Connect (OSTI)

    Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31T23:59:59.000Z

    Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of titanium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed.

  15. Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth

    SciTech Connect (OSTI)

    Batzill M.; Sutter P.; Dahal, A.; Addou, R.

    2012-06-11T23:59:59.000Z

    Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

  16. Vapor generation methods for explosives detection research. ...

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

    Vapor generation methods for explosives detection research. Vapor generation methods for explosives detection research. Abstract: The generation of calibrated vapor samples of...

  17. Electrolyte vapor condenser

    DOE Patents [OSTI]

    Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

    1983-02-08T23:59:59.000Z

    A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

  18. Method for deposition of a conductor in integrated circuits

    DOE Patents [OSTI]

    Creighton, J.R.; Dominguez, F.; Johnson, A.W.; Omstead, T.R.

    1997-09-02T23:59:59.000Z

    A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten. 2 figs.

  19. Method for deposition of a conductor in integrated circuits

    DOE Patents [OSTI]

    Creighton, J. Randall (Albuquerque, NM); Dominguez, Frank (Albuquerque, NM); Johnson, A. Wayne (Albuquerque, NM); Omstead, Thomas R. (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten.

  20. Organic vapor jet printing system

    DOE Patents [OSTI]

    Forrest, Stephen R

    2012-10-23T23:59:59.000Z

    An organic vapor jet printing system includes a pump for increasing the pressure of an organic flux.

  1. Variable temperature semiconductor film deposition

    DOE Patents [OSTI]

    Li, Xiaonan (Golden, CO); Sheldon, Peter (Lakewood, CO)

    1998-01-01T23:59:59.000Z

    A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  2. Variable temperature semiconductor film deposition

    DOE Patents [OSTI]

    Li, X.; Sheldon, P.

    1998-01-27T23:59:59.000Z

    A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  3. Robust Numerical Simulation of Porosity Evolution in Chemical Vapor In ltration II: Two Dimensional

    E-Print Network [OSTI]

    Jin, Shi

    -solid reactions with solid deposition are exempli#12;ed by the fabrication of ceramic matrix composites through #3) process, during which a matrix of ceramic #12;bers is chemically vapor deposited within a porous preform practical approach to fabricate ceramic composites. Among these composites, #12;ber-reinforced composites

  4. Stratified vapor generator

    DOE Patents [OSTI]

    Bharathan, Desikan (Lakewood, CO); Hassani, Vahab (Golden, CO)

    2008-05-20T23:59:59.000Z

    A stratified vapor generator (110) comprises a first heating section (H.sub.1) and a second heating section (H.sub.2). The first and second heating sections (H.sub.1, H.sub.2) are arranged so that the inlet of the second heating section (H.sub.2) is operatively associated with the outlet of the first heating section (H.sub.1). A moisture separator (126) having a vapor outlet (164) and a liquid outlet (144) is operatively associated with the outlet (124) of the second heating section (H.sub.2). A cooling section (C.sub.1) is operatively associated with the liquid outlet (144) of the moisture separator (126) and includes an outlet that is operatively associated with the inlet of the second heating section (H.sub.2).

  5. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    SciTech Connect (OSTI)

    Eric M. Suuberg; Vahur Oja

    1997-07-01T23:59:59.000Z

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  6. Diamond film growth from fullerene precursors

    DOE Patents [OSTI]

    Gruen, D.M.; Liu, S.; Krauss, A.R.; Pan, X.

    1997-04-15T23:59:59.000Z

    A method and system are disclosed for manufacturing diamond film. The method involves forming a fullerene vapor, providing a noble gas stream and combining the gas with the fullerene vapor, passing the combined fullerene vapor and noble gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the fullerene and deposition of a diamond film on a substrate. 10 figs.

  7. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOE Patents [OSTI]

    Schmitt, J.J. III; Halpern, B.L.

    1993-10-26T23:59:59.000Z

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures. 5 figures.

  8. Method for rapid, controllable growth and thickness, of epitaxial silicon films

    DOE Patents [OSTI]

    Wang, Qi (Littleton, CO); Stradins, Paul (Golden, CO); Teplin, Charles (Boulder, CO); Branz, Howard M. (Boulder, CO)

    2009-10-13T23:59:59.000Z

    A method of producing epitaxial silicon films on a c-Si wafer substrate using hot wire chemical vapor deposition by controlling the rate of silicon deposition in a temperature range that spans the transition from a monohydride to a hydrogen free silicon surface in a vacuum, to obtain phase-pure epitaxial silicon film of increased thickness is disclosed. The method includes placing a c-Si substrate in a HWCVD reactor chamber. The method also includes supplying a gas containing silicon at a sufficient rate into the reaction chamber to interact with the substrate to deposit a layer containing silicon thereon at a predefined growth rate to obtain phase-pure epitaxial silicon film of increased thickness.

  9. To estimate vapor pressure easily

    SciTech Connect (OSTI)

    Yaws, C.L.; Yang, H.C. (Lamar Univ., Beaumont, TX (USA))

    1989-10-01T23:59:59.000Z

    Vapor pressures as functions of temperature for approximately 700 major organic chemical compounds are given. The tabulation also gives the temperature range for which the data are applicable. Minimum and maximum temperatures are denoted by TMIN and TMAX. The Antoine equation that correlates vapor pressure as a function of temperature is described. A representative comparison of calculated and actual data values for vapor pressure is shown for ethyl alcohol. The coefficient tabulation is based on both literature (experimental data) and estimated values.

  10. Water Vapor Experiment Concludes

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1DOE AwardsDNitrateEnergyNews3 Water Vapor

  11. ARM Water Vapor IOP

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP Update Information on new,Scanning Radar323ARM Water Vapor IOP

  12. Structure/processing relationships in vapor-liquid-solid nanowire epitaxy

    E-Print Network [OSTI]

    Boles, Steven Tyler

    2010-01-01T23:59:59.000Z

    The synthesis of Si and III-V nanowires using the vapor-liquid-solid (VLS) growth mechanism and low-cost Si substrates was investigated. The VLS mechanism allows fabrication of heterostructures which are not readily ...

  13. Vapor Transport in Dry Soils

    SciTech Connect (OSTI)

    Gee, Glendon W.; Ward, Anderson L.

    2001-11-16T23:59:59.000Z

    Water-vapor movement in soils is a complex process, controlled by both diffusion and advection and influenced by pressure and thermal gradients acting across tortuous flow paths. Wide-ranging interest in water-vapor transport includes both theoretical and practical aspects. Just how pressure and thermal gradients enhance water-vapor flow is still not completely understood and subject to ongoing research. Practical aspects include dryland farming (surface mulching), water harvesting (aerial wells), fertilizer placement, and migration of contaminants at waste-sites. The following article describes the processes and practical applications of water-vapor transport, with emphasis on unsaturated (dry) soil systems.

  14. Vaporization of zinc from scrap

    SciTech Connect (OSTI)

    Ozturk, B.; Fruehan, R.J. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1996-12-31T23:59:59.000Z

    The rate of zinc vaporization from galvanized scrap was measured using a thermogravimetric apparatus along with chemical analysis. It is found that the rate of zinc vaporization is very fast in nitrogen and carbon monoxide atmospheres at temperatures higher than 950 C. At lower temperature rate decreases with decreasing temperature and is controlled by the gas phase mass transport. The simultaneous oxidation and vaporization of zinc occurs when the samples were heated in carbon dioxide and air. The current experimental results indicate that almost all of the zinc from scrap vaporizes during the heating process in a very short period of time after the temperature reaches above 850 C.

  15. Synthesis and deposition of metal nanoparticles by gas condensation process

    SciTech Connect (OSTI)

    Maicu, Marina, E-mail: marina.maicu@fep.fraunhofer.de; Glöß, Daniel; Frach, Peter [Fraunhofer Institut für Elektronenstrahl und Plasmatechnik, FEP, Winterbergstraße 28, 01277 Dresden (Germany); Schmittgens, Ralph; Gerlach, Gerald [Institut für Festkörperelektronik, IFE, TU Dresden, Helmholtz Straße 18, 01069 Dresden (Germany); Hecker, Dominic [Fraunhofer Institut für Elektronenstrahl und Plasmatechnik, FEP, Winterbergstraße 28, 01277 Dresden, Germany and Institut für Festkörperelektronik, IFE, TU Dresden, Helmholtz Straße 18, 01069 Dresden (Germany)

    2014-03-15T23:59:59.000Z

    In this work, the synthesis of Pt and Ag nanoparticles by means of the inert gas phase condensation of sputtered atomic vapor is presented. The process parameters (power, sputtering time, and gas flow) were varied in order to study the relationship between deposition conditions and properties of the nanoparticles such as their quantity, size, and size distribution. Moreover, the gas phase condensation process can be combined with a plasma enhanced chemical vapor deposition procedure in order to deposit nanocomposite coatings consisting of metallic nanoparticles embedded in a thin film matrix material. Selected examples of application of the generated nanoparticles and nanocomposites are discussed.

  16. Vapor spill pipe monitor

    DOE Patents [OSTI]

    Bianchini, G.M.; McRae, T.G.

    1983-06-23T23:59:59.000Z

    The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

  17. Hydride vapor phase epitaxy and characterization of high-quality ScN epilayers

    SciTech Connect (OSTI)

    Oshima, Yuichi, E-mail: OSHIMA.Yuichi@nims.go.jp; Víllora, Encarnación G.; Shimamura, Kiyoshi [Environment and Energy Materials Research Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-04-21T23:59:59.000Z

    The heteroepitaxial growth of ScN films was investigated on various substrates by hydride vapor phase epitaxy (HVPE). Single crystalline mirror-like ScN(100) and ScN(110) layers were successfully deposited on r- and m-plane sapphire substrates, respectively. Homogeneous stoichiometric films (N/Sc ratio 1.01?±?0.10) up to 40??m in thickness were deposited. Their mosaicity drastically improved with increasing the film thickness. The band gap was determined by optical methods to be 2.06?eV. Impurity concentrations including H, C, O, Si, and Cl were investigated through energy dispersive X-ray spectrometry and secondary ion mass spectrometry. As a result, it was found that the presence of impurities was efficiently suppressed in comparison with that of HVPE-grown ScN films reported in the past, which was possible thanks to the home-designed corrosion-free HVPE reactor. Room-temperature Hall measurements indicated that the residual free electron concentrations ranged between 10{sup 18}–10{sup 20}?cm{sup ?3}, which was markedly lower than the reported values. The carrier mobility increased monotonically with the decreasing in carrier concentration, achieving the largest value ever reported, 284?cm{sup 2}?V{sup ?1}?s{sup ?1} at n?=?3.7?×?10{sup 18}?cm{sup ?3}.

  18. In situ analysis of ash deposits from black liquor combustion

    SciTech Connect (OSTI)

    Bernath, P. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility]|[Univ. of Toronto, Ontario (Canada); Sinquefield, S.A. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility]|[Oregon State Univ., Eugene, OR (United States); Baxter, L.L.; Sclippa, G.; Rohlfing, C. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Barfield, M. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility]|[Univ. of Arizona, Tucson, AZ (United States)

    1996-05-01T23:59:59.000Z

    Aerosols formed during combustion of black liquor cause a significant fire-side fouling problem in pulp mill recovery boilers. The ash deposits reduce heat transfer effectiveness, plug gas passages, and contribute to corrosion. Both vapors and condensation aerosols lead to the formation of such deposits. The high ash content of the fuel and the low dew point of the condensate salts lead to a high aerosol and vapor concentration in most boilers. In situ measurements of the chemical composition of these deposits is an important step in gaining a fundamental understanding of the deposition process. Infrared emission spectroscopy is used to characterize the composition of thin film deposits resulting from the combustion of black liquor and the deposition of submicron aerosols and vapors. New reference spectra of Na{sub 2}SO{sub 4}, K{sub 2}SO{sub 4}, Na{sub 2}CO{sub 3} and K{sub 2}CO{sub 3} pure component films were recorded and compared with the spectra of the black liquor deposit. All of the black liquor emission bands were identified using a combination of literature data and ab initio calculations. Ab initio calculations also predict the locations and intensities of bands for the alkali vapors of interest. 39 refs., 9 figs.

  19. A study of vapor-liquid flow in porous media

    SciTech Connect (OSTI)

    Satik, Cengiz; Yortsos, Yanis C.

    1994-01-20T23:59:59.000Z

    We study the heat transfer-driven liquid-to-vapor phase change in single-component systems in porous media by using pore network models and flow visualization experiments. Experiments using glass micromodels were conducted. The flow visualization allowed us to define the rules for the numerical pore network model. A numerical pore network model is developed for vapor-liquid displacement where fluid flow, heat transfer and capillarity are included at the pore level. We examine the growth process at two different boundary conditions.

  20. Compositional Variations in Vapor Deposited Samarium Zirconate Coatings

    E-Print Network [OSTI]

    Wadley, Haydn

    section of the engine (the combustor and high pressure turbine). The blades at the inlet of the high temperatures instead have relied on the development of thermal barrier coating (TBC) systems. The thermal coat applied to the superalloy surface, (ii) a thermally grown oxide layer (TGO) that forms on the bond

  1. Micro Chemical Vapor Deposition for the Synthesis of Nanomaterials

    E-Print Network [OSTI]

    Zhou, Qin

    2011-01-01T23:59:59.000Z

    Journal of MicroElectroMechanical Systems, vol. 20, pp. 9-Chair MEMS (Microelectromechanical Systems) technologiesby MEMS (Microelectromechanical Systems) technologies many

  2. Vapor deposited samarium zirconate thermal barrier coatings Hengbei Zhao a,

    E-Print Network [OSTI]

    Wadley, Haydn

    technology for the gas turbine engines used for propulsion and power generation [1]. Through their ability conductivity (~2.1 W m- 1 K- 1 at 1000 T1200 °C [9]), its thermochemical compatibility with the underlying TGO

  3. Sandia National Laboratories: metal organic chemical vapor deposition

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

    Partnership, Research & Capabilities, Solid-State Lighting Solid state lighting (SSL), which uses light-emitting diodes (LEDs), has the potential to be 10 times more energy...

  4. A Multiscale Simulator for Low Pressure Chemical Vapor Deposition

    E-Print Network [OSTI]

    Advanced Custom Technologies, Motorola, Inc., Mail Drop M350, 2200 W. Broadway Rd., Mesa, AZ 85202 Timothy that govern the species and energy transport with chemical reactions throughout the reactor chamber, and (2

  5. A Multiscale Simulator for Low Pressure Chemical Vapor Deposition

    E-Print Network [OSTI]

    Advanced Custom Technologies, Motorola, Inc., Mail Drop M350, 2200 W. Broadway Rd., Mesa, AZ 85202 Timothy the equations that govern the species and energy transport with chemical reactions throughout the reactor

  6. Vapor-Wall Deposition in Chambers: Theoretical Considerations

    E-Print Network [OSTI]

    McVay, Renee C; Cappa, Christopher D; Seinfeld, John H

    2014-01-01T23:59:59.000Z

    aerosol size distribution changes continuously as particles grow by condensation and are lost by coagulation

  7. Hot-Wire Chemical Vapor Deposition (HWCVD) technologies - Energy Innovation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School football Highdefault Sign InDataCenterCenterPortal

  8. Vapor Retarder Classification - Building America Top Innovation...

    Energy Savers [EERE]

    the Top Innovation. See an example of vapor retarder best practices in action. Find other case studies of Building America projects across the country that utilizes vapor retarder...

  9. Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor Pressure Isotope Effects

    E-Print Network [OSTI]

    Chickos, James S.

    Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid hydrocarbons and their perdeuterated analogues have been determined by correlation-gas chromatography of cyclohexane-d12 and benzene-d6. Other hydrocarbons studied include the perdeuterated forms of hexane, toluene

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

    SciTech Connect (OSTI)

    Steven Brandt, E.; Grace, Jeremy M. [Eastman Kodak Company, 1999 Lake Avenue, Rochester, New York 14650-2022 (United States)

    2012-01-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Maydannik, Philipp S., E-mail: philipp.maydannik@lut.fi; Kääriäinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C. [Advanced Surface Technology Research Laboratory, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Söderlund, Mikko; Soininen, Pekka [Beneq Oy, P.O. Box 262, 01511 Vantaa (Finland); Johansson, Petri; Kuusipalo, Jurkka [Tampere University of Technology, Paper Converting and Packaging Technology, P.O. Box 589, 33101 Tampere (Finland); Moro, Lorenza; Zeng, Xianghui [Samsung Cheil Industries, San Jose R and D Center, 2186 Bering Drive, San Jose, California 95131 (United States)

    2014-09-01T23:59:59.000Z

    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 isostatic–isobaric 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.

  12. Ge-related faceting and segregation during the growth of metastable (GaAs){sub 1{minus}x}(Ge{sub 2}){sub x} alloy layers by metal{endash}organic vapor-phase epitaxy

    SciTech Connect (OSTI)

    Norman, A.G.; Olson, J.M.; Geisz, J.F.; Moutinho, H.R.; Mason, A.; Al-Jassim, M.M. [National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)] [National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States); Vernon, S.M. [Spire Corporation, One Patriots Park, Bedford, Massachusetts 01730 (United States)] [Spire Corporation, One Patriots Park, Bedford, Massachusetts 01730 (United States)

    1999-03-01T23:59:59.000Z

    (GaAs){sub 1{minus}x}(Ge{sub 2}){sub x} alloy layers, 0{lt}x{lt}0.22, have been grown by metal{endash}organic vapor-phase epitaxy on vicinal (001) GaAs substrates. Transmission electron microscopy revealed pronounced phase separation in these layers, resulting in regions of GaAs-rich zinc-blende and Ge-rich diamond cubic material that appears to lead to substantial band-gap narrowing. For x=0.1 layers, the phase-separated microstructure consisted of intersecting sheets of Ge-rich material on {l_brace}115{r_brace}B planes surrounding cells of GaAs-rich material, with little evidence of antiphase boundaries. Atomic force microscopy revealed {l_brace}115{r_brace}B surface faceting associated with the phase separation. {copyright} {ital 1999 American Institute of Physics.}

  13. Passive vapor extraction feasibility study

    SciTech Connect (OSTI)

    Rohay, V.J.

    1994-06-30T23:59:59.000Z

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft{sup 3}/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft{sup 3}/min air flow rates, passive vapor extraction is more cost effective below 100 ppm.

  14. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    SciTech Connect (OSTI)

    Banerjee, Amit; Banerjee, S. S., E-mail: satyajit@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur, 208016 (India)

    2014-05-15T23:59:59.000Z

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ?0.9 nms{sup ?1}. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  15. Laser induced thermophoresis and particulate deposition efficiency

    SciTech Connect (OSTI)

    Cipolla, J.; Morse, T.F.; Wang, C.Y.

    1983-07-01T23:59:59.000Z

    The interaction of laser radiation and an absorbing aerosol in a tube flow has been considered. The aerosol is produced by external heating of reactants as in the MCVD (Modified Chemical Vapor Deposition) process to produce submicron size particles in the manufacture of optical fiber preforms. These are subsequently deposited by thermophoretic forces on the inner wall of the tube as they are convected by a Poiseuille velocity profile. Axial laser radiation in the tube interacts with the absorbing particles, and the laser heating of the gas induces additional thermophoretic forces that markedly increase the efficiency of particulate deposition. A particle concentration dependent absorption coefficient that appears in the energy equation couples the energy equation to the equation of particle conservation, so that a non-linear set of coupled partial integrodifferential equations must be solved. Numerical solutions for aerosol particle trajectories, and thus deposition efficiencies, have been obtained. It is shown that laser enhanced thermophoresis markedly improves the deposition efficiency.

  16. Tribology Letters Vol. 10, No. 3, 2001 179 Activation of the SiC surface for vapor phase lubrication

    E-Print Network [OSTI]

    Gellman, Andrew J.

    above 500 C [2,3,11,12]. Since liquid lubricants cannot withstand such extreme conditions, a number deposition 1. Introduction The lubrication of ceramic surfaces working at extremely high temperatures has lubrication by Fe chemical vapor deposition from Fe(CO)5 Daxing Ren, Dougyong Sung and Andrew J. Gellman

  17. Portable vapor diffusion coefficient meter

    DOE Patents [OSTI]

    Ho, Clifford K. (Albuquerque, NM)

    2007-06-12T23:59:59.000Z

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  18. Control of pyrophoricity in deposits produced by electron beam evaporation of uranium

    SciTech Connect (OSTI)

    Clifford, J.

    1980-07-01T23:59:59.000Z

    A description is given of an apparatus for reducing the pyrophoricity of deposits of a material evaporated within a chamber comprising: a sealed chamber defined by an enclosure; means for providing within said chamber an atmosphere of generally non-reactive nature; a reservoir of a material to ve evaporated; means for directing a vapor of said material from said reservoir into said chamber; at least one surface within said chamber in the path of the directed vapor and on which at least portions of the vaporized material deposits; means for cooling said enclosure to a temperature at which said vapor deposits at a relatively low pyrophoric density; and means for maintaining a temperature for said collection surfaces higher than the enclosure temperature to promote deposition of said material at a relatively higher density.

  19. Growth mechanisms study of microcrystalline silicon deposited by SiH{sub 4}/H{sub 2} plasma using tailored voltage waveforms

    SciTech Connect (OSTI)

    Bruneau, B., E-mail: bastien.bruneau@polytechnique.edu; Johnson, E. V. [LPICM-CNRS, Ecole Polytechnique, route de Saclay, 91128 Palaiseau (France); Wang, J. [LPICM-CNRS, Ecole Polytechnique, route de Saclay, 91128 Palaiseau (France); ICARE China-Europe Institute for Clean and Renewable Energy at Huazhong University of Science and Technology, 1037 Luoyu Road, 430074 Wuhan (China); Dornstetter, J.-C. [LPICM-CNRS, Ecole Polytechnique, route de Saclay, 91128 Palaiseau (France); TOTAL New Energies, 24 cours Michelet, 92069 Paris La Défense Cedex (France)

    2014-02-28T23:59:59.000Z

    The use of Tailored Voltage Waveforms is a technique wherein one uses non-sinusoidal waveforms with a period equivalent to RF frequencies to excite a plasma. It has been shown to be an effective technique to decouple maximum Ion Bombardment Energy (IBE) from the ion flux at the surface of the electrodes. In this paper, we use it for the first time as a way to scan through the IBE in order to study the growth mechanism of hydrogenated microcrystalline silicon using a SiH{sub 4}/H{sub 2} chemistry. We find that at critical energies, a stepwise increase in the amorphous to microcrystalline transition thickness is observed, as detected by Real Time Spectroscopic Ellipsometry. The same energy thresholds (30?eV and 70?eV) are found to be very influential on the final surface morphology of the samples, as observed by Atomic Force Microscopy. These thresholds correspond to SiH{sub x}{sup +} bulk displacement (30?eV) and H{sub x}{sup +} (70?eV) surface displacement energies. A model is therefore proposed to account for the impact of these ions on the morphology of ?c-Si:H growth.

  20. Direct Visualization of Initial SEI Morphology and Growth Kinetics...

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

    Initial SEI Morphology and Growth Kinetics During Lithium Deposition by in situ Electrochemical Direct Visualization of Initial SEI Morphology and Growth Kinetics During Lithium...

  1. EFFECT OF FILTER TEMPERATURE ON TRAPPING ZINC VAPOR

    SciTech Connect (OSTI)

    Korinko, P.

    2011-03-25T23:59:59.000Z

    To address the {sup 65}Zn contamination issue in the TEF, a multi-task experimental program was initiated. The first experimental task was completed and is reported in Ref. 1. The results of the second experimental task are reported here. This task examined the effect of filter temperature on trapping efficiency and deposit morphology. Based on the first experimental tasks that examined filter pore size and trapping efficiency, stainless steel filter media with a 20 {micro}m pore size was selected. A series of experiments using these filters was conducted during this second task to determine the effect of filter temperature on zinc vapor trapping efficiency, adhesion and morphology. The tests were conducted with the filters heated to 60, 120, and 200 C; the zinc source material was heated to 400 C for all the experiments to provide a consistent zinc source. The samples were evaluated for mass change, deposit adhesion and morphology. As expected from the physical vapor deposition literature, a difference in deposit morphology and appearance was observed between the three filter temperatures. The filter held at 60 C had the largest average mass gain while the 120 and 200 C filters exhibited similar but lower weight gains. The standard deviations were large and suggest that all three temperatures exhibited comparable gains. No zinc was detected on the backside surface of the filters indicating high efficiency for front and internal trapping. A zinc rich deposit was formed on the surface of the 60 C filter. Based on a simple tape adhesion test, the surface zinc was readily removed from the 60 C filter while less zinc deposit was removed from the 120 and 200 C filter samples. It is surmised that the higher temperatures enable the zinc to deposit within the filter media rather than on the surface. Based on the findings that all three statistically trapped the same quantity of zinc vapor and that the higher temperatures resulted in a more adherent/better trapped product, operating the filters at 120 to 200 C is recommended.

  2. Computational Study of Catalyzed Growth of Single Wall Carbon Nanotubes 

    E-Print Network [OSTI]

    Zhao, Jin

    2010-01-14T23:59:59.000Z

    A recently developed chemical vapor deposition (CVD) synthesis process called CoMoCAT yields single-wall carbon nanotubes (SWCNT)s of controlled diameter and chirality, making them extremely attractive for technological ...

  3. Computational Study of Catalyzed Growth of Single Wall Carbon Nanotubes

    E-Print Network [OSTI]

    Zhao, Jin

    2010-01-14T23:59:59.000Z

    A recently developed chemical vapor deposition (CVD) synthesis process called CoMoCAT yields single-wall carbon nanotubes (SWCNT)s of controlled diameter and chirality, making them extremely attractive for technological applications...

  4. Carbon Nanotube Growth Using Ni Catalyst in Different Layouts

    E-Print Network [OSTI]

    Nguyen, H. Q.

    Vertically aligned carbon nanotubes have been grown using Ni as catalyst by plasma enhanced chemical vapor deposition system (PECVD) in various pre-patterned substrates. Ni was thermally evaporated on silicon substrates ...

  5. Deposition of dopant impurities and pulsed energy drive-in

    DOE Patents [OSTI]

    Wickboldt, Paul (Walnut Creek, CA); Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Ramon, CA); Ellingboe, Albert R. (Fremont, CA)

    1999-01-01T23:59:59.000Z

    A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques.

  6. Deposition of dopant impurities and pulsed energy drive-in

    DOE Patents [OSTI]

    Wickboldt, Paul (Walnut Creek, CA); Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Jose, CA); Ellingboe, Albert R. (Malahide, IE)

    2008-01-01T23:59:59.000Z

    A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques.

  7. Deposition of dopant impurities and pulsed energy drive-in

    DOE Patents [OSTI]

    Wickboldt, P.; Carey, P.G.; Smith, P.M.; Ellingboe, A.R.

    1999-06-29T23:59:59.000Z

    A semiconductor doping process which enhances the dopant incorporation achievable using the Gas Immersion Laser Doping (GILD) technique is disclosed. The enhanced doping is achieved by first depositing a thin layer of dopant atoms on a semiconductor surface followed by exposure to one or more pulses from either a laser or an ion-beam which melt a portion of the semiconductor to a desired depth, thus causing the dopant atoms to be incorporated into the molten region. After the molten region recrystallizes the dopant atoms are electrically active. The dopant atoms are deposited by plasma enhanced chemical vapor deposition (PECVD) or other known deposition techniques. 2 figs.

  8. New Crystal-Growth Methods for Producing Lattice-Matched Substrates for High-Temperature Superconductors

    SciTech Connect (OSTI)

    Boatner, L.A.

    2008-06-24T23:59:59.000Z

    This effort addressed the technical problem of identifying and growing, on a commercial scale, suitable single-crystal substrates for the subsequent deposition of epitaxial thin films of high temperature semiconductors such as GaN/AlN. The lack of suitable lattice-matched substrate materials was one of the major problem areas in the development of semiconducting devices for use at elevated temperatures as well as practical opto-electronic devices based on Al- and GaN technology. Such lattice-matched substrates are necessary in order to reduce or eliminate high concentrations of defects and dislocations in GaN/AlN and related epitaxial thin films. This effort concentrated, in particular, on the growth of single crystals of ZnO for substrate applications and it built on previous ORNL experience in the chemical vapor transport growth of large single crystals of zinc oxide. This combined expertise in the substrate growth area was further complemented by the ability of G. Eres and his collaborators to deposit thin films of GaN on the subject substrates and the overall ORNL capability for characterizing the quality of such films. The research effort consisted of research on the growth of two candidate substrate materials in conjunction with concurrent research on the growth and characterization of GaN films, i.e. the effort combined bulk crystal growth capabilities in the area of substrate production at both ORNL and the industrial partner, Commercial Crystal Growth Laboratories (CCL), Naples, Florida, with the novel thin-film deposition techniques previously developed in the ORNL SSD.

  9. Source replenishment device for vacuum deposition

    DOE Patents [OSTI]

    Hill, R.A.

    1986-05-15T23:59:59.000Z

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

  10. Image Storage in Hot Vapors

    E-Print Network [OSTI]

    L. Zhao; T. Wang; Y. Xiao; S. F. Yelin

    2007-10-22T23:59:59.000Z

    We theoretically investigate image propagation and storage in hot atomic vapor. A $4f$ system is adopted for imaging and an atomic vapor cell is placed over the transform plane. The Fraunhofer diffraction pattern of an object in the object plane can thus be transformed into atomic Raman coherence according to the idea of ``light storage''. We investigate how the stored diffraction pattern evolves under diffusion. Our result indicates, under appropriate conditions, that an image can be reconstructed with high fidelity. The main reason for this procedure to work is the fact that diffusion of opposite-phase components of the diffraction pattern interfere destructively.

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

    SciTech Connect (OSTI)

    Keuter, Thomas, E-mail: t.keuter@fz-juelich.de; Menzler, Norbert Heribert; Mauer, Georg; Vondahlen, Frank; Vaßen, Robert; Buchkremer, Hans Peter [Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-1), 52425 Jülich (Germany)

    2015-01-01T23:59:59.000Z

    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.

  12. CVD Growth of Carbon Nanostructures from Zirconia: Mechanisms and a Method for Enhancing Yield

    E-Print Network [OSTI]

    Kudo, Akira

    By excluding metals from synthesis, growth of carbon nanostructures via unreduced oxide nanoparticle catalysts offers wide technological potential. We report new observations of the mechanisms underlying chemical vapor ...

  13. Vapor explosion in the RIA-ST-4 experiment. [BWR

    SciTech Connect (OSTI)

    El-Genk, M.S.

    1980-01-01T23:59:59.000Z

    A concern in assuring the safety of commercial light water reactors (LWRs) is whether core overheating, during which molten fuel is produced, can lead to massive vaporization of the coolant and shock pressurization of the system due to an energetic molten fuel-coolant interaction (MFCI). The RIA-ST-4 experiment was one of four scoping tests in the Reactivity Initiated Accident (RIA) Test Series which is being conducted in the Power Burst Facility (PBF) to define an energy deposition failure threshold and to determine modes and consequences of fuel rod failure during a postulated boiling water reactor (BWR) control rod drop accident.

  14. Hydrogen Cars and Water Vapor

    E-Print Network [OSTI]

    Colorado at Boulder, University of

    misidentified as "zero-emissions vehicles." Fuel cell vehicles emit water vapor. A global fleet could have, with discernible effects on people and ecosystems. The broad environmental effects of fuel cell vehicles. This cycle is currently under way with hydrogen fuel cells. As fuel cell cars are suggested as a solution

  15. Vapor phase modifiers for oxidative coupling

    DOE Patents [OSTI]

    Warren, Barbara K. (Charleston, WV)

    1991-01-01T23:59:59.000Z

    Volatilized metal compounds retard vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

  16. Evaporation system and method for gas jet deposition of thin film materials

    DOE Patents [OSTI]

    Schmitt, Jerome J. (New Haven, CT); Halpern, Bret L. (Bethany, CT)

    1994-01-01T23:59:59.000Z

    A method and apparatus for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases.

  17. Time-resolved surface infrared spectroscopy during atomic layer deposition of TiO{sub 2} using tetrakis(dimethylamido)titanium and water

    SciTech Connect (OSTI)

    Sperling, Brent A., E-mail: brent.sperling@nist.gov; Hoang, John; Kimes, William A.; Maslar, James E. [Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Dr., Stop 8320, Gaithersburg, Maryland 20899-8320 (United States); Steffens, Kristen L. [Biomolecular Measurement Division, National Institute of Standards and Technology, 100 Bureau Dr., Stop 8362, Gaithersburg, Maryland 20899-8362 (United States); Nguyen, Nhan V. [Semiconductor and Dimensional Metrology Division, National Institute of Standards and Technology, 100 Bureau Dr., Stop 8120, Gaithersburg, Maryland 20899-8120 (United States)

    2014-05-15T23:59:59.000Z

    Atomic layer deposition of titanium dioxide using tetrakis(dimethylamido)titanium (TDMAT) and water vapor is studied by reflection-absorption infrared spectroscopy (RAIRS) with a time resolution of 120?ms. At 190?°C and 240?°C, a decrease in the absorption from adsorbed TDMAT is observed without any evidence of an adsorbed product. Ex situ measurements indicate that this behavior is not associated with an increase in the impurity concentration or a dramatic change in the growth rate. A desorbing decomposition product is consistent with these observations. RAIRS also indicates that dehydroxylation of the growth surface occurs only among one type of surface hydroxyl groups. Molecular water is observed to remain on the surface and participates in reactions even at a relatively high temperature (110?°C) and with long purge times (30?s)

  18. Vapor canister heater for evaporative emissions systems

    SciTech Connect (OSTI)

    Bishop, R.P.; Berg, P.G.

    1987-01-01T23:59:59.000Z

    Automotive evaporative emissions systems use a charcoal canister to store evaporative hydrocarobn emissions. These stored vapors are later purged and burned during engine operation. Under certain conditions the engine cannot completely purge the canister of the stored fuel vapors, which results in a decreased vapor storage capacity in the canister. A self-regulating PTC (Positive Temperature Coefficient) heater has been developed to warm the purge air as it enters the canister, in order to provide thermal energy for increased release of the vapors from charcoal sites. This paper describes the construction and operation of the vapor canister heater as it relates to improved evaporative emission system performance.

  19. Heteroepitaxial growth of GaN/Si (111) junctions in ammonia-free atmosphere: Charge transport, optoelectronic, and photovoltaic properties

    SciTech Connect (OSTI)

    Saron, K. M. A.; Hashim, M. R. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Penang 11800 (Malaysia); Allam, Nageh K. [Energy Materials Laboratory (EML), Department of Physics, School of Sciences and Engineering, The American University in Cairo, New Cairo 11835 (Egypt)

    2013-03-28T23:59:59.000Z

    We report the catalyst-free growth of gallium nitride (GaN) nanostructures on n-Si (111) substrates using physical vapor deposition via thermal evaporation of GaN powder at 1150 Degree-Sign C in the absence of NH{sub 3} gas. Scanning electron microscopy and energy dispersive x-ray analysis indicate that the growth rate of GaN nanostructures varies with deposition time. Photoluminescence spectra showed the suppression of the UV emission and the enhancement of the visible band emission with increasing the deposition time. The fabricated GaN nanostructures exhibited p-type behavior at the GaN/Si interface, which can be related to the diffusion of Ga into the Si substrate. The obtained lowest reflection and highest transmittance over a wide wavelength range (450-750 nm) indicate the high quality of the fabricated GaN films. Hall-effect measurements showed that all fabricated films have p-type behavior with decreasing electron concentration from 10{sup 21} to 10{sup 12} cm{sup -3} and increasing the electron mobility from 50 to 225 cm{sup 2}/V s with increasing the growth time. The fabricated solar cell based on the 1 h-deposited GaN nanostructures on n-Si (111) substrate showed a well-defined rectifying behavior with a rectification ratio larger than 8.32 Multiplication-Sign 10{sup 3} in dark. Upon illumination (30 mW/cm{sup 2}), the 1 h-deposited heterojunction solar cell device showed a conversion efficiency of 5.78%. The growth of GaN in the absence of NH{sub 3} gas has strong effect on the morphological, optical, and electrical properties and consequently on the efficiency of the solar cell devices made of such layers.

  20. Means and method for vapor generation

    DOE Patents [OSTI]

    Carlson, Larry W. (Oswego, IL)

    1984-01-01T23:59:59.000Z

    A liquid, in heat transfer contact with a surface heated to a temperature well above the vaporization temperature of the liquid, will undergo a multiphase (liquid-vapor) transformation from 0% vapor to 100% vapor. During this transition, the temperature driving force or heat flux and the coefficients of heat transfer across the fluid-solid interface, and the vapor percentage influence the type of heating of the fluid--starting as "feedwater" heating where no vapors are present, progressing to "nucleate" heating where vaporization begins and some vapors are present, and concluding with "film" heating where only vapors are present. Unstable heating between nucleate and film heating can occur, accompanied by possibly large and rapid temperature shifts in the structures. This invention provides for injecting into the region of potential unstable heating and proximate the heated surface superheated vapors in sufficient quantities operable to rapidly increase the vapor percentage of the multiphase mixture by perhaps 10-30% and thereby effectively shift the multiphase mixture beyond the unstable heating region and up to the stable film heating region.

  1. Growth and characterizations of GaN micro-rods on graphene films for flexible light emitting diodes

    SciTech Connect (OSTI)

    Chung, Kunook; Beak, Hyeonjun; Tchoe, Youngbin; Oh, Hongseok; Yi, Gyu-Chul, E-mail: gcyi@snu.ac.kr [Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Yoo, Hyobin; Kim, Miyoung [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-09-01T23:59:59.000Z

    We report the growth of GaN micro-rods and coaxial quantum-well heterostructures on graphene films, together with structural and optical characterization, for applications in flexible optical devices. Graphene films were grown on Cu foil by means of chemical vapor deposition, and used as the substrates for the growth of the GaN micro-rods, which were subsequently transferred onto SiO{sub 2}/Si substrates. Highly Si-doped, n-type GaN micro-rods were grown on the graphene films using metal–organic chemical vapor deposition. The growth and vertical alignment of the GaN micro-rods, which is a critical factor for the fabrication of high-performance light-emitting diodes (LEDs), were characterized using electron microscopy and X-ray diffraction. The GaN micro-rods exhibited promising photoluminescence characteristics for optoelectronic device applications, including room-temperature stimulated emission. To fabricate flexible LEDs, In{sub x}Ga{sub 1–x}N/GaN multiple quantum wells and a p-type GaN layer were deposited coaxially on the GaN micro-rods, and transferred onto Ag-coated polymer substrates using lift-off. Ti/Au and Ni/Au metal layers were formed to provide electrical contacts to the n-type and p-type GaN regions, respectively. The micro-rod LEDs exhibited intense emission of visible light, even after transfer onto the flexible polymer substrate, and reliable operation was achieved following numerous cycles of mechanical deformation.

  2. Control of flow through a vapor generator

    DOE Patents [OSTI]

    Radcliff, Thomas D.

    2005-11-08T23:59:59.000Z

    In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.

  3. III-V Nanowire Growth Mechanism: V/III Ratio and Temperature Effects

    E-Print Network [OSTI]

    Wang, Deli

    ,17,18 The growth experiments reported in this paper were performed in a horizontal OMVPE growth tube using to be determined by the local V/III ratio, which is dependent on the input precursor flow rates, growth temperature to favor vapor-solid (VS) surface growth over VLS NW growth. By tuning both the group III flow rate

  4. Coupling apparatus for a metal vapor laser

    DOE Patents [OSTI]

    Ball, Don G. (Livermore, CA); Miller, John L. (Dublin, CA)

    1993-01-01T23:59:59.000Z

    Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

  5. Coupling apparatus for a metal vapor laser

    DOE Patents [OSTI]

    Ball, D.G.; Miller, J.L.

    1993-02-23T23:59:59.000Z

    Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

  6. Overview of chemical vapor infiltration

    SciTech Connect (OSTI)

    Besmann, T.M.; Stinton, D.P.; Lowden, R.A.

    1993-06-01T23:59:59.000Z

    Chemical vapor infiltration (CVI) is developing into a commercially important method for the fabrication of continuous filament ceramic composites. Current efforts are focused on the development of an improved understanding of the various processes in CVI and its modeling. New approaches to CVI are being explored, including pressure pulse infiltration and microwave heating. Material development is also proceeding with emphasis on improving the oxidation resistance of the interfacial layer between the fiber and matrix. This paper briefly reviews these subjects, indicating the current state of the science and technology.

  7. Wick for metal vapor laser

    DOE Patents [OSTI]

    Duncan, David B. (Livermore, CA)

    1992-01-01T23:59:59.000Z

    An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.

  8. Robust Numerical Simulation of Porosity Evolution in Chemical Vapor Infiltration I: Two Space

    E-Print Network [OSTI]

    Jin, Shi

    infiltration (CVI) process is an important approach to fabricating ceramic matrix composite(CMC's). Two. In CVI a vapor precursor of the matrix material, such as methyl­ trichlorosilane (MTS), diffuses through the inter­fiber void. As matrix growth progresses, avenues for gas transport become more tortuous and begin

  9. Vapor phase modifiers for oxidative coupling

    DOE Patents [OSTI]

    Warren, B.K.

    1991-12-17T23:59:59.000Z

    Volatilized metal compounds are described which are capable of retarding vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

  10. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, V.J.; Johnson, S.A.

    1999-08-03T23:59:59.000Z

    A vapor sample detection method is described where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample. 13 figs.

  11. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, Vincent J. (Downers Grove, IL); Johnson, Stanley A. (Countryside, IL)

    1999-01-01T23:59:59.000Z

    A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

  12. Optimization of ion-atomic beam source for deposition of GaN ultrathin films

    SciTech Connect (OSTI)

    Mach, Jind?ich, E-mail: mach@fme.vutbr.cz; Kolíbal, Miroslav; Zlámal, Jakub; Voborny, Stanislav; Bartošík, Miroslav; Šikola, Tomáš [Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno (Czech Republic); CEITEC BUT, Brno University of Technology, Technická 10, 61669 Brno (Czech Republic); Šamo?il, Tomáš [Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno (Czech Republic)

    2014-08-15T23:59:59.000Z

    We describe the optimization and application of an ion-atomic beam source for ion-beam-assisted deposition of ultrathin films in ultrahigh vacuum. The device combines an effusion cell and electron-impact ion beam source to produce ultra-low energy (20–200 eV) ion beams and thermal atomic beams simultaneously. The source was equipped with a focusing system of electrostatic electrodes increasing the maximum nitrogen ion current density in the beam of a diameter of ?15 mm by one order of magnitude (j ? 1000 nA/cm{sup 2}). Hence, a successful growth of GaN ultrathin films on Si(111) 7 × 7 substrate surfaces at reasonable times and temperatures significantly lower (RT, 300?°C) than in conventional metalorganic chemical vapor deposition technologies (?1000?°C) was achieved. The chemical composition of these films was characterized in situ by X-ray Photoelectron Spectroscopy and morphology ex situ using Scanning Electron Microscopy. It has been shown that the morphology of GaN layers strongly depends on the relative Ga-N bond concentration in the layers.

  13. Tropospheric water vapor and climate sensitivity

    SciTech Connect (OSTI)

    Schneider, E.K.; Kirtman, B.P.; Lindzen, R.S. [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States)] [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States)

    1999-06-01T23:59:59.000Z

    Estimates are made of the effect of changes in tropospheric water vapor on the climate sensitivity to doubled carbon dioxide (CO{sub 2}) using a coarse resolution atmospheric general circulation model coupled to a slab mixed layer ocean. The sensitivity of the model to doubled CO{sub 2} is found as the difference between the equilibrium responses for control and doubled CO{sub 2} cases. Clouds are specified to isolate the water vapor feedback. Experiments in which the water vapor distribution is specified rather than internally calculated are used to find the contribution of water vapor in various layers and latitude belts to the sensitivity. The contribution of water vapor in layers of equal mass to the climate sensitivity varies by about a factor of 2 with height, with the largest contribution coming from layers between 450 and 750 mb, and the smallest from layers above 230 mb. The positive feedback on the global mean surface temperature response to doubled CO{sub 2} from water vapor above 750 mb is about 2.6 times as large as that from water vapor below 750 mb. The feedback on global mean surface temperature due to water vapor in the extratropical free troposphere is about 50% larger than the feedback due to the lower-latitude free troposphere water vapor. Several important sources of nonlinearity of the radiative heating rates were identified in the process of constructing the specified cloud and water vapor fields. These are (1) the interaction of clouds and solar radiation, which produces much more reflection of solar radiation for time mean clouds than for the instantaneous clouds; (2) the correlation of clouds and water vapor, which produces less downward longwave radiation at the ground for correlated clouds and water vapor than when these fields are independent; and (3) the interaction of water vapor with long wave radiation, which produces less downward longwave radiation at the ground of the average over instantaneous water vapor distributions than of the time mean water vapor distribution.

  14. Photobiomolecular deposition of metallic particles and films

    DOE Patents [OSTI]

    Hu, Zhong-Cheng

    2005-02-08T23:59:59.000Z

    The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

  15. Low-temperature GaN growth on silicon substrates by single gas-source epitaxy and photo-excitation

    SciTech Connect (OSTI)

    Trivedi, R.A.; Tolle, J.; Chizmeshya, A.V.G.; Roucka, R.; Ritter, Cole; Kouvetakis, J.; Tsong, I.S.T. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Department of Physics and Astronomy, Arizona State University, Tempe, Arizona 85287-1504 (United States)

    2005-08-15T23:59:59.000Z

    We report a unique low-temperature growth method for epitaxial GaN on Si(111) substrates via a ZrB{sub 2}(0001) buffer layer. The method utilizes the decomposition of a single gas-source precursor (D{sub 2}GaN{sub 3}){sub 3} on the substrate surface to form GaN. The film growth process is further promoted by irradiation of ultraviolet light to enhance the growth rate and ordering of the film. The best epitaxial film quality is achieved at a growth temperature of 550 deg. C with a growth rate of 3 nm/min. The films exhibit intense photoluminescence emission at 10 K with a single peak at 3.48 eV, indicative of band-edge emission for a single-phase hexagonal GaN film. The growth process achieved in this study is compatible with low Si processing temperatures and also enables direct epitaxy of GaN on ZrB{sub 2} in contrast to conventional metalorganic chemical vapor deposition based approaches.

  16. LNG fire and vapor control system technologies

    SciTech Connect (OSTI)

    Konzek, G.J.; Yasutake, K.M.; Franklin, A.L.

    1982-06-01T23:59:59.000Z

    This report provides a review of fire and vapor control practices used in the liquefied natural gas (LNG) industry. Specific objectives of this effort were to summarize the state-of-the-art of LNG fire and vapor control; define representative LNG facilities and their associated fire and vapor control systems; and develop an approach for a quantitative effectiveness evaluation of LNG fire and vapor control systems. In this report a brief summary of LNG physical properties is given. This is followed by a discussion of basic fire and vapor control design philosophy and detailed reviews of fire and vapor control practices. The operating characteristics and typical applications and application limitations of leak detectors, fire detectors, dikes, coatings, closed circuit television, communication systems, dry chemicals, water, high expansion foam, carbon dioxide and halogenated hydrocarbons are described. Summary descriptions of a representative LNG peakshaving facility and import terminal are included in this report together with typical fire and vapor control systems and their locations in these types of facilities. This state-of-the-art review identifies large differences in the application of fire and vapor control systems throughout the LNG industry.

  17. Quantitative organic vapor-particle sampler

    DOE Patents [OSTI]

    Gundel, Lara (Berkeley, CA); Daisey, Joan M. (Walnut Creek, CA); Stevens, Robert K. (Cary, NC)

    1998-01-01T23:59:59.000Z

    A quantitative organic vapor-particle sampler for sampling semi-volatile organic gases and particulate components. A semi-volatile organic reversible gas sorbent macroreticular resin agglomerates of randomly packed microspheres with the continuous porous structure of particles ranging in size between 0.05-10 .mu.m for use in an integrated diffusion vapor-particle sampler.

  18. 6, 80698095, 2006 Water vapor in Asian

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of Sciences, Beijing, China 2 National Center for Atmospheric Research, Boulder, CO, USA Received: 23 May 2006 vapor from European Center for Medium-Range Weather20 Forecasts (ECMWF) analyses. 1 Introduction Upper Tropospheric Water Vapor (UTWV) is a key greenhouse gas which exerts a major influence on the energy balance

  19. Methods for improved growth of group III nitride buffer layers

    DOE Patents [OSTI]

    Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro

    2014-07-15T23:59:59.000Z

    Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphology of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).

  20. Oxygen-assisted room-temperature deposition of CoPt3 films with perpendicular magnetic anisotropy

    E-Print Network [OSTI]

    Hellman, Frances

    Oxygen-assisted room-temperature deposition of CoPt3 films with perpendicular magnetic anisotropy B Jolla, California 92093 Received 23 July 2002; accepted 30 September 2002 Trace amounts of oxygen CoPt3 grown by vapor deposition at or slightly above room temperature. Oxygen is known to act

  1. Vapor Synthesis and Thermal Modification of Supportless Platinum-Ruthenium Nanotubes and Application as Methanol Electrooxidation Catalysts

    SciTech Connect (OSTI)

    Atkinson III, Robert [University of Tennessee (UT); Unocic, Raymond R [ORNL; Unocic, Kinga A [ORNL; Veith, Gabriel M [ORNL; Papandrew, Alexander B [ORNL; Zawodzinski, Thomas A [ORNL

    2015-01-01T23:59:59.000Z

    Metallic, mixed-phase, and alloyed bimetallic Pt-Ru nanotubes were synthesized by a novel route based on the sublimation of metal acetylacetonate precursors and their subsequent vapor deposition within anodic alumina templates. Nanotube architectures were tuned by thermal annealing treatments. As-synthesized nanotubes are composed of nanoparticulate, metallic platinum and hydrous ruthenium oxide whose respective thicknesses depend on the sample chemical composition. The Pt-decorated, hydrous Ru oxide nanotubes may be thermally annealed to promote a series of chemical and physical changes to the nanotube structures including alloy formation, crystallite growth and morphological evolution. Annealed Pt-Ru alloy nanotubes and their as-synthesized analogs demonstrate relatively high specific activities for the oxidation of methanol. As-synthesized, mixed-phase Pt-Ru nanotubes (0.39 mA/cm2) and metallic alloyed Pt64Ru36NTs (0.33 mA/cm2) have considerably higher area-normalized activities than PtRu black (0.22 mA/cm2) at 0.65 V vs. RHE.

  2. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    SciTech Connect (OSTI)

    ANDERSON, T.J.

    2006-12-20T23:59:59.000Z

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  3. Stacked vapor fed amtec modules

    DOE Patents [OSTI]

    Sievers, Robert K. (North Huntingdon, PA)

    1989-01-01T23:59:59.000Z

    The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta"-alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta"-alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta"-alumina solid electrolyte of the tubular member. A transition piece is positioned about the interior of the member and contacts the transporting means. The transition piece divides the member into a first cell and a second cell such that each first and second cell has a beta"-alumina solid electrolyte, a first and second porous electrode and a grid. The transition piece conducts electrons from the interior of the tubular member. There is supply means for supplying sodium to the transporting means. Preferably the supply means is a shell which surrounds the tubular member and is operated at a temperature such that the vaporized sodium condenses thereon. Returning means for returning the condensed sodium from the shell to the transporting means provides a continuous supply of liquid sodium to the transporting means. Also, there are first conducting means for conducting electric current from the transition piece which extends through the shell, and second conducting means for conducting electric current to the grid of the first cell which extends through the shell.

  4. Quantitative Infrared Intensity Studies of Vapor-PhaseGlyoxal...

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

    Infrared Intensity Studies of Vapor-Phase Glyoxal,Methylglyoxal, and 2,3-Butanedione (Diacetyl) with Quantitative Infrared Intensity Studies of Vapor-Phase Glyoxal,Methylglyoxal,...

  5. Absolute integrated intensities of vapor-phase hydrogen peroxide...

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

    Absolute integrated intensities of vapor-phase hydrogen peroxide (H202) in the mid-infrared at atmospheric pressure. Absolute integrated intensities of vapor-phase hydrogen...

  6. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. | EMSL

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

    Acidic Polymers for Chemical Vapor Sensing. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. Abstract: A review with 171 references. Hydrogen-bond acidic polymers for...

  7. In-growth of an electrically active defect in high-purity silicon after proton irradiation

    SciTech Connect (OSTI)

    Nylandsted Larsen, A.; Juul Pedersen, H.; Christian Petersen, M. [Department of Physics and Astronomy, and Interdisciplinary Nanoscience Center, Aarhus University, Aarhus (Denmark)] [Department of Physics and Astronomy, and Interdisciplinary Nanoscience Center, Aarhus University, Aarhus (Denmark); Privitera, V. [CNR-IMM, Institute of Microelectronics and Microsystems, Catania (Italy)] [CNR-IMM, Institute of Microelectronics and Microsystems, Catania (Italy); Gurimskaya, Y.; Mesli, A. [IM2NP, CNRS (UMR 7334) and Université Aix-Marseille, 13397 Marseille Cedex 20 (France)] [IM2NP, CNRS (UMR 7334) and Université Aix-Marseille, 13397 Marseille Cedex 20 (France)

    2013-12-14T23:59:59.000Z

    Defect-related energy levels in the lower half of the band gap of silicon have been studied with transient-capacitance techniques in high-purity, carbon and oxygen lean, plasma-enhanced chemical-vapor deposition grown, n-and p-type silicon layers after 2-MeV proton irradiations at temperatures at or just below room temperature. The in-growth of a distinct line in deep-level transient spectroscopy spectra, corresponding to a level in the band gap at E{sub V} + 0.357 eV where E{sub V} is the energy of the valence band edge, takes place for anneal temperatures at around room temperature with an activation energy of 0.95 ± 0.08 eV. The line disappears at an anneal temperature of around 450 K. The corresponding defect is demonstrated not to contain boron, carbon, oxygen, or phosphorus. Possible defect candidates are discussed.

  8. Homoepitaxial Growth of Single Crystal Diamond Membranes for Quantum Information Processing

    E-Print Network [OSTI]

    Igor Aharonovich; Jonathan C. Lee; Andrew P. Magyar; Bob B. Buckley; Christopher G. Yale; David D. Awschalom; Evelyn L. Hu

    2012-01-18T23:59:59.000Z

    Fabrication of devices designed to fully harness the unique properties of quantum mechanics through their coupling to quantum bits (qubits) is a prominent goal in the field of quantum information processing (QIP). Among various qubit candidates, nitrogen vacancy (NV) centers in diamond have recently emerged as an outstanding platform for room temperature QIP. However, formidable challenges still remain in processing diamond and in the fabrication of thin diamond membranes, which are necessary for planar photonic device engineering. Here we demonstrate epitaxial growth of single crystal diamond membranes using a conventional microwave chemical vapor deposition (CVD) technique. The grown membranes, only a few hundred nanometers thick, show bright luminescence, excellent Raman signature and good NV center electronic spin coherence times. Microdisk cavities fabricated from these membranes exhibit quality factors of up to 3000, overlapping with NV center emission. Our methodology offers a scalable approach for diamond device fabrication for photonics, spintronics, optomechanics and sensing applications.

  9. Homoepitaxial Growth of Single Crystal Diamond Membranes for Quantum Information Processing

    E-Print Network [OSTI]

    Aharonovich, Igor; Magyar, Andrew P; Buckley, Bob B; Yale, Christopher G; Awschalom, David D; Hu, Evelyn L

    2011-01-01T23:59:59.000Z

    Fabrication of devices designed to fully harness the unique properties of quantum mechanics through their coupling to quantum bits (qubits) is a prominent goal in the field of quantum information processing (QIP). Among various qubit candidates, nitrogen vacancy (NV) centers in diamond have recently emerged as an outstanding platform for room temperature QIP. However, formidable challenges still remain in processing diamond and in the fabrication of thin diamond membranes, which are necessary for planar photonic device engineering. Here we demonstrate epitaxial growth of single crystal diamond membranes using a conventional microwave chemical vapor deposition (CVD) technique. The grown membranes, only a few hundred nanometers thick, show bright luminescence, excellent Raman signature and good NV center electronic spin coherence times. Microdisk cavities fabricated from these membranes exhibit quality factors of up to 3000, overlapping with NV center emission. Our methodology offers a scalable approach for dia...

  10. Growth and characterization of horizontal GaN wires on silicon

    SciTech Connect (OSTI)

    Zou, Xinbo; May Lau, Kei, E-mail: eekmlau@ust.hk [Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Kowloon (Hong Kong); HKUST Jockey Club Institute for Advanced Study, The Hong Kong University of Science and Technology, Kowloon (Hong Kong); Lu, Xing [Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Kowloon (Hong Kong); Lucas, Ryan [Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Kuech, Thomas F. [HKUST Jockey Club Institute for Advanced Study, The Hong Kong University of Science and Technology, Kowloon (Hong Kong); Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Choi, Jonathan W.; Gopalan, Padma [Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2014-06-30T23:59:59.000Z

    We report the growth of in-plane GaN wires on silicon by metalorganic chemical vapor deposition. Triangular-shaped GaN microwires with semi-polar sidewalls are observed to grow on top of a GaN/Si template patterned with nano-porous SiO{sub 2}. With a length-to-thickness ratio ?200, the GaN wires are well aligned along the three equivalent ? 112{sup ¯}0 ? directions. Micro-Raman measurements indicate negligible stress and a low defect density inside the wires. Stacking faults were found to be the only defect type in the GaN wire by cross-sectional transmission electron microscopy. The GaN wires exhibited high conductivity, and the resistivity was 20–30 m? cm, regardless of the wire thickness. With proper heterostructure and doping design, these highly aligned GaN wires are promising for photonic and electronic applications monolithically integrated on silicon.

  11. Numerical simulations of epitaxial growth process in MOVPE reactor as a tool for design of modern semiconductors for high power electronics

    SciTech Connect (OSTI)

    Skibinski, Jakub; Wejrzanowski, Tomasz [Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141, 02507 Warsaw (Poland); Caban, Piotr [Institute of Electronic Materials Technology, Wolczynska 133, 01919 Warsaw (Poland); Kurzydlowski, Krzysztof J. [Warsaw University of Technology, Faculty of Materials Science and Engineering Woloska, 141, 02507 Warsaw (Poland)

    2014-10-06T23:59:59.000Z

    In the present study numerical simulations of epitaxial growth of gallium nitride in Metal Organic Vapor Phase Epitaxy reactor AIX-200/4RF-S is addressed. Epitaxial growth means crystal growth that progresses while inheriting the laminar structure and the orientation of substrate crystals. One of the technological problems is to obtain homogeneous growth rate over the main deposit area. Since there are many agents influencing reaction on crystal area such as temperature, pressure, gas flow or reactor geometry, it is difficult to design optimal process. According to the fact that it's impossible to determine experimentally the exact distribution of heat and mass transfer inside the reactor during crystal growth, modeling is the only solution to understand the process precisely. Numerical simulations allow to understand the epitaxial process by calculation of heat and mass transfer distribution during growth of gallium nitride. Including chemical reactions in numerical model allows to calculate the growth rate of the substrate and estimate the optimal process conditions for obtaining the most homogeneous product.

  12. Recovering hydrocarbons from hydrocarbon-containing vapors

    DOE Patents [OSTI]

    Mirza, Zia I. (La Verne, CA); Knell, Everett W. (Los Alamitos, CA); Winter, Bruce L. (Danville, CA)

    1980-09-30T23:59:59.000Z

    Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

  13. 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: fhirose@yz.yamagata-u.ac.jp [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan)

    2015-01-01T23:59:59.000Z

    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 Hf–OH plays a role as an adsorption site for TEMAH. The reaction mechanism of room temperature HfO{sub 2} ALD is discussed in this paper.

  14. Photo deposition of metal with far uv radiation

    SciTech Connect (OSTI)

    Blum, S.E.; Brown, K.H.

    1984-05-29T23:59:59.000Z

    A method for depositing a refractory metal onto a substrate is described wherein a carbonyl compound vapor of the metal in the vicinity of or on the substrate is photodecomposed by ultraviolet radiation of wavelengths less than 200 nm. This causes the release of atoms of the metal, which then condense onto the substrate. In an example, a tungsten layer is photodeposited by this method onto a GaAs semiconductor layer to form a Schottky barrier diode.

  15. Growth process of microcrystalline silicon studied by combined photoluminescence and Raman investigations

    SciTech Connect (OSTI)

    Klossek, A.; Mankovics, D.; Ratzke, M. [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany)] [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany); Arguirov, T.; Kittler, M. [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany) [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany); IHP Microelectronics, Im Technologiepark 25, D-15236 Frankfurt (Oder) (Germany); Kirner, S.; Gabriel, O.; Stannowski, B.; Schlatmann, R. [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany)] [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany); Friedrich, F. [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany) [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany); Department of Semiconductor Devices, Technische Universität Berlin, Sekr. E2, Einsteinufer 19, D-10587 Berlin (Germany)

    2013-12-14T23:59:59.000Z

    Plasma enhanced chemical vapor deposition of silicon on glass substrates leads to formation of silicon amorphous films with partial crystallization of nano-grains in the amorphous matrix. We studied the transition of amorphous to microcrystalline silicon during such deposition. Formation of silicon nano-grains was detected by means of photoluminescence and Raman spectroscopy. The crystalline fraction and the mean size of the nano-grains were estimated by the position and the intensity of the peaks in the Raman spectrum. We showed that the fraction of crystalline silicon in the layers and the size of the nano-grains are strongly dependent on the growth conditions. The photoluminescence spectra exhibit distinct features related to recombination in the amorphous and in the crystalline phases. A significant narrowing of the photoluminescence peak related to the amorphous phase with increasing crystalline fraction indicates a structural modification in the amorphous silicon. It suggests an ordering process occurring before the start of the actual crystallization. A peak at about 1.4 eV was associated with isolated nano-crystalline grains within the amorphous matrix. A correlation between the peak energy and grain size was found, indicating effects of carrier quantum confinement. The experimental results confirm the established theoretical models for growth of microcrystalline silicon films.

  16. Particle deposition in ventilation ducts

    E-Print Network [OSTI]

    Sippola, Mark R.

    2002-01-01T23:59:59.000Z

    and An Evaluation of Thermophoretic Deposition Rates C.1of estimated thermophoretic deposition velocities, v th+ ,of estimated thermophoretic deposition velocities, v th+ ,

  17. An advanced vapor-compression desalination system 

    E-Print Network [OSTI]

    Lara Ruiz, Jorge Horacio Juan

    2006-04-12T23:59:59.000Z

    Currently, the two dominant desalination methods are reverse osmosis (RO) and multi-stage flash (MSF). RO requires large capital investment and maintenance, whereas MSF is too energy intensive. An innovative vapor-compression desalination system...

  18. Modeling of LNG Pool Spreading and Vaporization

    E-Print Network [OSTI]

    Basha, Omar 1988-

    2012-11-20T23:59:59.000Z

    In this work, a source term model for estimating the rate of spreading and vaporization of LNG on land and sea is introduced. The model takes into account the composition changes of the boiling mixture, the varying thermodynamic properties due...

  19. Solid-Vapor Sorption Refrigeration Systems 

    E-Print Network [OSTI]

    Graebel, W.; Rockenfeller, U.; Kirol, L.

    1991-01-01T23:59:59.000Z

    SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL DR. UWE ROCKENFELLER MR. LANCE KIROL Engineer President Chief Engineer Rocky Research Rocky Research Rocky Research Boulder city, NV Boulder city, NV Boulder City, NV Abstract.... Complex compounds have a number of advantages as working media, including: 43 SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL Engineer Rocky Research Boulder city, NV DR. UWE ROCKENFELLER President Rocky Research Boulder city, NV MR...

  20. CONTROLLED GROWTH OF CARBON NANOTUBES ON CONDUCTIVE METAL SUBSTRATES FOR ENERGY STORAGE APPLICATIONS

    SciTech Connect (OSTI)

    Brown, P.; Engtrakul, C.

    2009-01-01T23:59:59.000Z

    The impressive mechanical and electronic properties of carbon nanotubes (CNTs) make them ideally suited for use in a variety of nanostructured devices, especially in the realm of energy production and storage. In particular, vertically-aligned CNT “forests” have been the focus of increasing investigation for use in supercapacitor electrodes and as hydrogen adsorption substrates. Vertically-aligned CNT growth was attempted on metal substrates by waterassisted chemical vapor deposition (CVD). CNT growth was catalyzed by iron-molybdenum (FeMo) nanoparticle catalysts synthesized by a colloidal method, which were then spin-coated onto Inconel® foils. The substrates were loaded into a custom-built CVD apparatus, where CNT growth was initiated by heating the substrates to 750 °C under the fl ow of He, H2, C2H4 and a controlled amount of water vapor. The resultant CNTs were characterized by a variety of methods including Raman spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), and the growth parameters were varied in an attempt to optimize the purity and growth yield of the CNTs. The surface area and hydrogen adsorption characteristics of the CNTs were quantifi ed by the Brunauer- Emmett-Teller (BET) and Sieverts methods, and their capacitance was measured via cyclic voltammetry. While vertically-aligned CNT growth could not be verifi ed, TEM and SEM analysis indicated that CNT growth was still obtained, resulting in multiwalled CNTs of a wide range in diameter along with some amorphous carbon impurities. These microscopy fi ndings were reinforced by Raman spectroscopy, which resulted in a G/D ratio ranging from 1.5 to 3 across different samples, suggestive of multiwalled CNTs. Changes in gas fl ow rates and water concentration during CNT growth were not found to have a discernable effect on the purity of the CNTs. The specifi c capacitance of a CNT/FeMo/Inconel® electrode was found to be 3.2 F/g, and the BET surface area of a characteristic CNT sample was measured to be 232 m2/g with a cryogenic (77K) hydrogen storage of 0.85 wt%. This level of hydrogen adsorption is slightly higher than that predicted by the Chahine rule, indicating that these CNTs may bind hydrogen more strongly than other carbonaceous materials. More work is needed to confi rm and determine the reason for increased hydrogen adsorption in these CNTs, and to test them for use as catalyst support networks. This study demonstrates the feasibility of producing CNTs for energy storage applications using water-assisted CVD.

  1. Growth of Large-Area Single- and Bi-Layer Graphene by Controlled Carbon Precipitation on Polycrystalline Ni Surfaces

    E-Print Network [OSTI]

    Reina, Alfonso

    2009-01-01T23:59:59.000Z

    We report graphene films composed mostly of one or two layers of graphene grown by controlled carbon precipitation on the surface of polycrystalline Ni thin films during atmospheric chemical vapor deposition (CVD). Controlling ...

  2. Sealable stagnation flow geometries for the uniform deposition of materials and heat

    DOE Patents [OSTI]

    McCarty, Kevin F. (Livermore, CA); Kee, Robert J. (Livermore, CA); Lutz, Andrew E. (Alamo, CA); Meeks, Ellen (Livermore, CA)

    2001-01-01T23:59:59.000Z

    The present invention employs a constrained stagnation flow geometry apparatus to achieve the uniform deposition of materials or heat. The present invention maximizes uniform fluxes of reactant gases to flat surfaces while minimizing the use of reagents and finite dimension edge effects. This results, among other things, in large area continuous films that are uniform in thickness, composition and structure which is important in chemical vapor deposition processes such as would be used for the fabrication of semiconductors.

  3. Environmentally focused patterning and processing of polymer thin films by initiated chemical vapor deposition (iCVD) and oxidative chemical vapor deposition (oCVD)

    E-Print Network [OSTI]

    Trujillo, Nathan J. (Nathan Jeffrey)

    2010-01-01T23:59:59.000Z

    The new millennium has brought fourth many technological innovations made possible by the advancement of high speed integrated circuits. The materials and energy requirements for a microchip is orders of magnitude higher ...

  4. Apparatus for depositing hard coating in a nozzle orifice

    DOE Patents [OSTI]

    Flynn, P.L.; Giammarise, A.W.

    1995-02-21T23:59:59.000Z

    The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance to erosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice`s interior surfaces by the vapor deposited coating formed from the reaction gas. 2 figs.

  5. Process for depositing hard coating in a nozzle orifice

    DOE Patents [OSTI]

    Flynn, Paul L. (5139 Fox Park Dr., Fairview, PA 16415); Giammarise, Anthony W. (527 Lincoln Ave., Erie, PA 16505)

    1991-01-01T23:59:59.000Z

    The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance toerosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas.

  6. Process for depositing hard coating in a nozzle orifice

    DOE Patents [OSTI]

    Flynn, P.L.; Giammarise, A.W.

    1991-10-29T23:59:59.000Z

    The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance to erosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas. 2 figures.

  7. Apparatus for depositing hard coating in a nozzle orifice

    DOE Patents [OSTI]

    Flynn, Paul L. (Fairview, PA); Giammarise, Anthony W. (Erie, PA)

    1995-01-01T23:59:59.000Z

    The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance to erosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas.

  8. Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment: Quarterly technical report, June 1, 1987-August 31, 1987

    SciTech Connect (OSTI)

    Rosner, D.E.

    1987-09-01T23:59:59.000Z

    Our emphasis in the present program is on experimentally validating and developing rational, theoretical methods of predicting the role of inertia and ash particle thermophoresis in determining net deposition rates. We also wish to quantify how simultaneous vapor deposition (e.g., alkali sulfate) can influence the sticking and erosion associated with impacting particles. 6 refs., 2 figs.

  9. Metal vapor target for precise studies of ion-atom collisions

    SciTech Connect (OSTI)

    Chen, W., E-mail: w.chen@gsi.de; Vorobyev, G.; Herfurth, F.; Hillenbrand, P.-M.; Spillmann, U. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Guo, D. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 Gansu (China); Trotsenko, S. [Helmholtz-Institut Jena Fröbelstieg 3, 07743 Jena (Germany); Gumberidze, A. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); FIAS Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main (Germany); Stöhlker, Th. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Helmholtz-Institut Jena Fröbelstieg 3, 07743 Jena (Germany)

    2014-05-15T23:59:59.000Z

    Although different ion-atom collisions have been studied in various contexts, precise values of cross-sections for many atomic processes were seldom obtained. One of the main uncertainties originates from the value of target densities. In this paper, we describe a unique method to measure a target density precisely with a combination of physical vapor deposition and inductively coupled plasma optical emission spectrometry. This method is preliminarily applied to a charge transfer cross-section measurement in collisions between highly charged ions and magnesium vapor. The final relative uncertainty of the target density is less than 2.5%. This enables the precise studies of atomic processes in ion-atom collisions, even though in the trial test the deduction of precise capture cross-sections was limited by other systematic errors.

  10. Method and Apparatus for Concentrating Vapors for Analysis

    DOE Patents [OSTI]

    Grate, Jay W. (West Richland, WA); Baldwin, David L. (Kennewick, WA); Anheier, Jr., Norman C. (Richland, WA)

    2008-10-07T23:59:59.000Z

    An apparatus and method are disclosed for pre-concentrating gaseous vapors for analysis. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable. Vapors sorbed and concentrated within the bed of the apparatus can be thermally desorbed achieving at least partial separation of vapor mixtures. The apparatus is suitable, e.g., for preconcentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than for direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications.

  11. FORMATION OF COSMIC CRYSTALS IN HIGHLY SUPERSATURATED SILICATE VAPOR PRODUCED BY PLANETESIMAL BOW SHOCKS

    SciTech Connect (OSTI)

    Miura, H.; Yamada, J.; Tsukamoto, K.; Nozawa, J. [Department of Earth Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Tanaka, K. K.; Yamamoto, T. [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Nakamoto, T., E-mail: miurah@m.tohoku.ac.j [Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan)

    2010-08-10T23:59:59.000Z

    Several lines of evidence suggest that fine silicate crystals observed in primitive meteorite and interplanetary dust particles (IDPs) nucleated in a supersaturated silicate vapor followed by crystalline growth. We investigated evaporation of {mu}m-sized silicate particles heated by a bow shock produced by a planetesimal orbiting in the gas in the early solar nebula and condensation of crystalline silicate from the vapor thus produced. Our numerical simulation of shock-wave heating showed that these {mu}m-sized particles evaporate almost completely when the bow shock is strong enough to cause melting of chondrule precursor dust particles. We found that the silicate vapor cools very rapidly with expansion into the ambient unshocked nebular region; for instance, the cooling rate is estimated to be as high as 2000 K s{sup -1} for a vapor heated by a bow shock associated with a planetesimal of radius 1 km. The rapid cooling of the vapor leads to nonequilibrium gas-phase condensation of dust at temperatures much lower than those expected from the equilibrium condensation. It was found that the condensation temperatures are lower by a few hundred K or more than the equilibrium temperatures. This explains the results of the recent experimental studies of condensation from a silicate vapor that condensation in such large supercooling reproduces morphologies similar to those of silicate crystals found in meteorites. Our results strongly suggest that the planetesimal bow shock is one of the plausible sites for formation of not only chondrules but also other cosmic crystals in the early solar system.

  12. Diode pumped alkali vapor fiber laser

    DOE Patents [OSTI]

    Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

    2007-10-23T23:59:59.000Z

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  13. Diode pumped alkali vapor fiber laser

    DOE Patents [OSTI]

    Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

    2006-07-26T23:59:59.000Z

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  14. Adsorption of water vapor on reservoir rocks

    SciTech Connect (OSTI)

    Not Available

    1993-07-01T23:59:59.000Z

    Progress is reported on: adsorption of water vapor on reservoir rocks; theoretical investigation of adsorption; estimation of adsorption parameters from transient experiments; transient adsorption experiment -- salinity and noncondensible gas effects; the physics of injection of water into, transport and storage of fluids within, and production of vapor from geothermal reservoirs; injection optimization at the Geysers Geothermal Field; a model to test multiwell data interpretation for heterogeneous reservoirs; earth tide effects on downhole pressure measurements; and a finite-difference model for free surface gravity drainage well test analysis.

  15. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, T.

    1988-03-15T23:59:59.000Z

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself. 4 figs.

  16. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, Terry (Tracy, CA)

    1988-01-01T23:59:59.000Z

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself.

  17. ZnO/Cu(InGa)Se.sub.2 solar cells prepared by vapor phase Zn doping

    SciTech Connect (OSTI)

    Ramanathan, Kannan; Hasoon, Falah S.; Asher, Sarah E.; Dolan, James; Keane, James C.

    2007-02-20T23:59:59.000Z

    A process for making a thin film ZnO/Cu(InGa)Se.sub.2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se.sub.2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se.sub.2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se.sub.2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se.sub.2.

  18. ZnO/Cu(InGa)Se2 solar cells prepared by vapor phase Zn doping

    DOE Patents [OSTI]

    Ramanathan, Kannan; Hasoon, Falah S.; Asher, Sarah E.; Dolan, James; Keane, James C.

    2007-02-20T23:59:59.000Z

    A process for making a thin film ZnO/Cu(InGa)Se2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se2 layer on the metal back contact on the glass substrate to a temperature range between about 100.degree. C. to about 250.degree. C.; subjecting the heated layer of Cu(InGa)Se2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se2.

  19. Effect of hydrogen plasma irradiation of catalyst films on growth of carbon nanotubes filled with iron nanowires

    SciTech Connect (OSTI)

    Sato, Hideki, E-mail: sato@elec.mie-u.ac.jp; Kubonaka, Nobuo; Nagata, Atsushi; Fujiwara, Yuji [Graduate School of Engineering, Mie University, 1577 Kurima-machiya-cho, Tsu 514-8507 (Japan)

    2014-03-15T23:59:59.000Z

    Carbon nanotubes filled with iron (Fe-filled CNTs) show shape anisotropy on account of the high aspect ratio of magnetic nanowires, and are promising candidates for various applications, such as magnetic recording media, probes for scanning force microscopy, and medical treatment for cancer. The ability to appropriately control the magnetic properties of CNTs for those applications is desirable. In this study, the authors investigated magnetic properties of Fe-filled CNTs synthesized by thermal chemical vapor deposition for the purpose of tuning their coercivity. Here, the authors implemented hydrogen plasma irradiation of catalyst film that was previously deposited on a substrate as a catalyst layer. This treatment activates the catalyst film and thus enhances the growth of the Fe-filled CNTs. It was confirmed that the H{sub 2} plasma irradiation enhances the growth of the CNTs in terms of increasing their length and diameter compared to CNTs without irradiation. On the other hand, the coercivity of Fe-filled CNTs dropped to approximately half of those without H{sub 2} plasma irradiation. This is probably due to a decrease in the aspect ratio of the Fe nanowires, which results from the increase in their diameter. Furthermore, the crystal structure of the Fe nanowires may affect the coercivity.

  20. Solution deposition assembly

    DOE Patents [OSTI]

    Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

    2014-01-21T23:59:59.000Z

    Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

  1. Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions 

    E-Print Network [OSTI]

    Kirol, L.

    1987-01-01T23:59:59.000Z

    Chemical heat pumps utilizing liquid-vapor reactions can be configured in forms analogous to electric drive vapor-compression heat pumps and heat activated absorption heat pumps. Basic thermodynamic considerations eliminate some heat pumps and place...

  2. Moisture Durability of Vapor Permeable Insulating Sheathing (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-10-01T23:59:59.000Z

    In this project, Building America team Building Science Corporation researched some of the ramifications of using exterior, vapor permeable insulation on retrofit walls with vapor permeable cavity insulation. Retrofit strategies are a key factor in reducing exterior building stock consumption.

  3. Vapor intrusion modeling : limitations, improvements, and value of information analyses

    E-Print Network [OSTI]

    Friscia, Jessica M. (Jessica Marie)

    2014-01-01T23:59:59.000Z

    Vapor intrusion is the migration of volatile organic compounds (VOCs) from a subsurface source into the indoor air of an overlying building. Vapor intrusion models, including the Johnson and Ettinger (J&E) model, can be ...

  4. OPTIMIZATION OF INJECTION INTO VAPOR-DOMINATED GEOTHERMAL

    E-Print Network [OSTI]

    Stanford University

    OPTIMIZATION OF INJECTION INTO VAPOR-DOMINATED GEOTHERMAL RESERVOIRS CONSIDERING ADSORPTION governing the behavior of vapor- dominated geothermal reservoirs. These mechanisms affect both was to determine the most effective injection strategy once these two effects are considered. Geothermal reservoir

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

    SciTech Connect (OSTI)

    Haider, Ali; Kayaci, Fatma; Uyar, Tamer; Biyikli, Necmi, E-mail: biyikli@unam.bilkent.edu.tr [National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, Ankara 06800 (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara 06800 (Turkey); Ozgit-Akgun, Cagla [National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, Ankara 06800 (Turkey); Okyay, Ali Kemal [National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, Ankara 06800 (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara 06800 (Turkey); Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, Ankara 06800 (Turkey)

    2014-09-01T23:59:59.000Z

    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.

  6. Advancing Explosives Detection Capabilities: Vapor Detection

    ScienceCinema (OSTI)

    Atkinson, David

    2014-07-24T23:59:59.000Z

    A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

  7. Vaporization of synthetic fuels. Final report. [Thesis

    SciTech Connect (OSTI)

    Sirignano, W.A.; Yao, S.C.; Tong, A.Y.; Talley, D.

    1983-01-01T23:59:59.000Z

    The problem of transient droplet vaporization in a hot convective environment is examined. The main objective of the present study is to develop an algorithm for the droplet vaporization which is simple enough to be feasibly incorporated into a complete spray combustion analysis and yet will also account for the important physics such as liquid-phase internal circulation, unsteady droplet heating and axisymmetric gas-phase convection. A simplified liquid-phase model has been obtained based on the assumption of the existence of a Hill's spherical vortex inside the droplet together with some approximations made in the governing diffusion equation. The use of the simplified model in a spray situation has also been examined. It has been found that droplet heating and vaporization are essentially unsteady and droplet temperature is nonuniform for a significant portion of its lifetime. It has also been found that the droplet vaporization characteristic can be quite sensitive to the particular liquid-phase and gas-phase models. The results of the various models are compared with the existing experimental data. Due to large scattering in the experimental measurements, particularly the droplet diameter, no definite conclusion can be drawn based on the experimental data. Finally, certain research problems which are related to the present study are suggested for future studies.

  8. Atomic-vapor-laser isotope separation

    SciTech Connect (OSTI)

    Davis, J.I.

    1982-10-01T23:59:59.000Z

    This paper gives a brief history of the scientific considerations leading to the development of laser isotope separation (LIS) processes. The close relationship of LIS to the broader field of laser-induced chemical processes is evaluated in terms of physical criteria to achieve an efficient production process. Atomic-vapor LIS processes under development at Livermore are reviwed. 8 figures.

  9. Program performs vapor-liquid equilibrium calculations

    SciTech Connect (OSTI)

    Rice, V.L.

    1982-06-28T23:59:59.000Z

    A program designed for the Hewlett-Packard HP-41CV or 41C calculators solves basic vapor-liquid equilibrium problems, including figuring the dewpoint, bubblepoint, and equilibrium flash. The algorithm uses W.C. Edmister's method for predicting ideal-solution K values.

  10. Effects of capillarity and vapor adsorption in the depletion of vapor-dominated geothermal reservoirs

    SciTech Connect (OSTI)

    Pruess, Karsten; O'Sullivan, Michael

    1992-01-01T23:59:59.000Z

    Vapor-dominated geothermal reservoirs in natural (undisturbed) conditions contain water as both vapor and liquid phases. The most compelling evidence for the presence of distributed liquid water is the observation that vapor pressures in these systems are close to saturated vapor pressure for measured reservoir temperatures (White et al., 1971; Truesdell and White, 1973). Analysis of natural heat flow conditions provides additional, indirect evidence for the ubiquitous presence of liquid. From an analysis of the heat pipe process (vapor-liquid counterflow) Preuss (1985) inferred that effective vertical permeability to liquid phase in vapor-dominated reservoirs is approximately 10{sup 17} m{sup 2}, for a heat flux of 1 W/m{sup 2}. This value appears to be at the high end of matrix permeabilities of unfractured rocks at The Geysers, suggesting that at least the smaller fractures contribute to liquid permeability. For liquid to be mobile in fractures, the rock matrix must be essentially completely liquid-saturated, because otherwise liquid phase would be sucked from the fractures into the matrix by capillary force. Large water saturation in the matrix, well above the irreducible saturation of perhaps 30%, has been shown to be compatible with production of superheated steam (Pruess and Narasimhan, 1982). In response to fluid production the liquid phase will boil, with heat of vaporization supplied by the reservoir rocks. As reservoir temperatures decline reservoir pressures will decline also. For depletion of ''bulk'' liquid, the pressure would decline along the saturated vapor pressure curve, while for liquid held by capillary and adsorptive forces inside porous media, an additional decline will arise from ''vapor pressure lowering''. Capillary pressure and vapor adsorption effects, and associated vapor pressure lowering phenomena, have received considerable attention in the geothermal literature, and also in studies related to geologic disposal of heat generating nuclear wastes, and in the drying of porous materials. Geothermally oriented studies were presented by Chicoine et al. (1977), Hsieh and Ramey (1978, 1981), Herkelrath et al. (1983), and Nghiem and Ramey (1991). Nuclear waste-related work includes papers by Herkelrath and O'Neal (1985), Pollock (1986), Eaton and Bixler (1987), Pruess et al. (1990), Nitao (1990), and Doughty and E'ruess (1991). Applications to industrial drying of porous materials have been discussed by Hamiathy (1969) arid Whitaker (1977). This paper is primarily concerned with evaluating the impact of vapor pressure lowering (VPL) effects on the depletion behavior of vapor-dominated reservoirs. We have examined experimental data on vapor adsorption and capillary pressures in an effort to identify constitutive relationships that would be applicable to the tight matrix rocks of vapor-dominated systems. Numerical simulations have been performed to evaluate the impact of these effects on the depletion of vapor-dominated reservoirs.

  11. Modeling engine oil vaporization and transport of the oil vapor in the piston ring pack on internal combustion engines

    E-Print Network [OSTI]

    Cho, Yeunwoo, 1973-

    2004-01-01T23:59:59.000Z

    A model was developed to study engine oil vaporization and oil vapor transport in the piston ring pack of internal combustion engines. With the assumption that the multi-grade oil can be modeled as a compound of several ...

  12. Development of hybrid organic-inorganic light emitting diodes using conducting polymers deposited by oxidative chemical vapor deposition process

    E-Print Network [OSTI]

    Chelawat, Hitesh

    2010-01-01T23:59:59.000Z

    Difficulties with traditional methods of synthesis and film formation for conducting polymers, many of which are insoluble, motivate the development of CVD methods. Indeed, conjugated polymers with rigid linear backbones ...

  13. Ash deposit workshop: Class outline

    SciTech Connect (OSTI)

    Hatt, R. [Commercial Testing & Engineering Co., Lexington, KY (United States)

    1996-12-31T23:59:59.000Z

    Ash deposits formed from the combustion of coal and other fuels have plagued the steam production industry from the start. The ash fusion test has been around for over eighty years. As steam plant size increased, so have the problems associated with ash deposits. This workshop is designed to cover: (1) The basic types of deposits. (2) Causes of deposits. (3) Analytical procedures for resolving, or at least providing information about deposits and fuels, and (4) Deposit removal and reduction techniques.

  14. Evaporation system and method for gas jet deposition of thin film materials

    DOE Patents [OSTI]

    Schmitt, J.J.; Halpern, B.L.

    1994-10-18T23:59:59.000Z

    A method and apparatus are disclosed for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases. 8 figs.

  15. Water, Vapor, and Salt Dynamics in a Hot Repository

    SciTech Connect (OSTI)

    Bahrami, Davood; Danko, George [Department of Mining Engineering, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV, 89557 (United States); Walton, John [Department of Civil Engineering, University of Texas at El Paso, 500 W. University, El Paso, TX, 79968 (United States)

    2007-07-01T23:59:59.000Z

    The purpose of this paper is to report the results of a new model study examining the high temperature nuclear waste disposal concept at Yucca Mountain using MULTIFLUX, an integrated in-drift- and mountain-scale thermal-hydrologic model. The results show that a large amount of vapor flow into the drift is expected during the period of above-boiling temperatures. This phenomenon makes the emplacement drift a water/moisture attractor during the above-boiling temperature operation. The evaporation of the percolation water into the drift gives rise to salt accumulation in the rock wall, especially in the crown of the drift for about 1500 years in the example. The deposited salts over the drift footprint, almost entirely present in the fractures, may enter the drift either by rock fall or by water drippage. During the high temperature operation mode, the barometric pressure variation creates fluctuating relative humidity in the emplacement drift with a time period of approximately 10 days. Potentially wet and dry conditions and condensation on salt-laden drift wall sections may adversely affect the storage environment. Salt accumulations during the above-boiling temperature operation must be sufficiently addressed to fully understand the waste package environment during the thermal period. Until the questions are resolved, a below-boiling repository design is favored where the Alloy-22 will be less susceptible to localized corrosion. (authors)

  16. Metal vapor laser including hot electrodes and integral wick

    DOE Patents [OSTI]

    Ault, Earl R. (Livermore, CA); Alger, Terry W. (Tracy, CA)

    1995-01-01T23:59:59.000Z

    A metal vapor laser, specifically one utilizing copper vapor, is disclosed herein. This laser utilizes a plasma tube assembly including a thermally insulated plasma tube containing a specific metal, e.g., copper, and a buffer gas therein. The laser also utilizes means including hot electrodes located at opposite ends of the plasma tube for electrically exciting the metal vapor and heating its interior to a sufficiently high temperature to cause the metal contained therein to vaporize and for subjecting the vapor to an electrical discharge excitation in order to lase. The laser also utilizes external wicking arrangements, that is, wicking arrangements located outside the plasma tube.

  17. Metal vapor laser including hot electrodes and integral wick

    DOE Patents [OSTI]

    Ault, E.R.; Alger, T.W.

    1995-03-07T23:59:59.000Z

    A metal vapor laser, specifically one utilizing copper vapor, is disclosed herein. This laser utilizes a plasma tube assembly including a thermally insulated plasma tube containing a specific metal, e.g., copper, and a buffer gas therein. The laser also utilizes means including hot electrodes located at opposite ends of the plasma tube for electrically exciting the metal vapor and heating its interior to a sufficiently high temperature to cause the metal contained therein to vaporize and for subjecting the vapor to an electrical discharge excitation in order to lase. The laser also utilizes external wicking arrangements, that is, wicking arrangements located outside the plasma tube. 5 figs.

  18. Industrial Heat Pumps Using Solid/Vapor Working Fluids

    E-Print Network [OSTI]

    Rockenfeller, U.

    with vapor re-compression recovery systems. The state-of-the-art heat pump equipment employing liquid/vapor working fluids fulfills the requirements only in some applications. The employment of solid/vapor complex compounds leads to 'nore cost effective... allows for firing temperatures much higher than possible with liquid/vapor systems. The high energy density per unit mass and the independence of the vapor pressure from the refrigerant concentration (p = f (T), p "# f( x)) over a wide range leads...

  19. GaSb molecular beam epitaxial growth on p-InP(001) and passivation with in situ deposited Al{sub 2}O{sub 3} gate oxide

    SciTech Connect (OSTI)

    Merckling, C.; Brammertz, G.; Hoffmann, T. Y.; Caymax, M.; Dekoster, J. [Interuniversity Microelectronics Center (IMEC vzw), Kapeldreef 75, 3001, Leuven (Belgium); Sun, X. [Katholieke Universiteit Leuven, Celestijnelaan 200D, 3001, Leuven (Belgium); Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520-8284 (United States); Alian, A.; Heyns, M. [Interuniversity Microelectronics Center (IMEC vzw), Kapeldreef 75, 3001, Leuven (Belgium); Katholieke Universiteit Leuven, Celestijnelaan 200D, 3001, Leuven (Belgium); Afanas'ev, V. V. [Katholieke Universiteit Leuven, Celestijnelaan 200D, 3001, Leuven (Belgium)

    2011-04-01T23:59:59.000Z

    The integration of high carrier mobility materials into future CMOS generations is presently being studied in order to increase drive current capability and to decrease power consumption in future generation CMOS devices. If III-V materials are the candidates of choice for n-type channel devices, antimonide-based semiconductors present high hole mobility and could be used for p-type channel devices. In this work we first demonstrate the heteroepitaxy of fully relaxed GaSb epilayers on InP(001) substrates. In a second part, the properties of the Al{sub 2}O{sub 3}/GaSb interface have been studied by in situ deposition of an Al{sub 2}O{sub 3} high-{kappa} gate dielectric. The interface is abrupt without any substantial interfacial layer, and is characterized by high conduction and valence band offsets. Finally, MOS capacitors show well-behaved C-V with relatively low D{sub it} along the bandgap, these results point out an efficient electrical passivation of the Al{sub 2}O{sub 3}/GaSb interface.

  20. Oxide vapor distribution from a high-frequency sweep e-beam system

    SciTech Connect (OSTI)

    Chow, R.; Tassano, P.L.; Tsujimoto, N.

    1995-03-01T23:59:59.000Z

    Oxide vapor distributions have been determined as a function of operating parameters of a high frequency sweep e-beam source combined with a programmable sweep controller. We will show which parameters are significant, the parameters that yield the broadest oxide deposition distribution, and the procedure used to arrive at these conclusions. A design-of-experimental strategy was used with five operating parameters: evaporation rate, sweep speed, sweep pattern (pre-programmed), phase speed (azimuthal rotation of the pattern), profile (dwell time as a function of radial position). A design was chosen that would show which of the parameters and parameter pairs have a statistically significant effect on the vapor distribution. Witness flats were placed symmetrically across a 25 inches diameter platen. The stationary platen was centered 24 inches above the e-gun crucible. An oxide material was evaporated under 27 different conditions. Thickness measurements were made with a stylus profilometer. The information will enable users of the high frequency e-gun systems to optimally locate the source in a vacuum system and understand which parameters have a major effect on the vapor distribution.

  1. Precision micro drilling with copper vapor lasers

    SciTech Connect (OSTI)

    Chang, J.J.; Martinez, M.W.; Warner, B.E.; Dragon, E.P.; Huete, G.; Solarski, M.E.

    1994-09-02T23:59:59.000Z

    The authors have developed a copper vapor laser based micro machining system using advanced beam quality control and precision wavefront tilting technologies. Micro drilling has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratio up to 1:40 have been consistently drilled on a variety of metals with good quality. For precision trepanned holes, the hole-to-hole size variation is typically within 1% of its diameter. Hole entrance and exit are both well defined with dimension error less than a few microns. Materialography of sectioned holes shows little (sub-micron scale) recast layer and heat affected zone with surface roughness within 1--2 microns.

  2. Atomic vapor spectroscopy in integrated photonic structures

    E-Print Network [OSTI]

    Ritter, Ralf; Pernice, Wolfram; Kübler, Harald; Pfau, Tilman; Löw, Robert

    2015-01-01T23:59:59.000Z

    We investigate an integrated optical chip immersed in atomic vapor providing several waveguide geometries for spectroscopy applications. The narrow-band transmission through a silicon nitride waveguide and interferometer is altered when the guided light is coupled to a vapor of rubidium atoms via the evanescent tail of the waveguide mode. We use grating couplers to couple between the waveguide mode and the radiating wave, which allow for addressing arbitrary coupling positions on the chip surface. The evanescent atom-light interaction can be numerically simulated and shows excellent agreement with our experimental data. This work demonstrates a next step towards miniaturization and integration of alkali atom spectroscopy and provides a platform for further fundamental studies of complex waveguide structures.

  3. Method for crystal growth control

    DOE Patents [OSTI]

    Yates, Douglas A. (Burlington, MA); Hatch, Arthur E. (Waltham, MA); Goldsmith, Jeff M. (Medford, MA)

    1981-01-01T23:59:59.000Z

    The growth of a crystalline body of a selected material is controlled so that the body has a selected cross-sectional shape. The apparatus is of the type which includes the structure normally employed in known capillary die devices as well as means for observing at least the portion of the surfaces of the growing crystalline body and the meniscus (of melt material from which the body is being pulled) including the solid/liquid/vapor junction in a direction substantially perpendicular to the meniscus surface formed at the junction when the growth of the crystalline body is under steady state conditions. The cross-sectional size of the growing crystalline body can be controlled by determining which points exhibit a sharp change in the amount of reflected radiation of a preselected wavelength and controlling the speed at which the body is being pulled or the temperature of the growth pool of melt so as to maintain those points exhibiting a sharp change at a preselected spatial position relative to a predetermined reference position. The improvement comprises reference object means positioned near the solid/liquid/vapor junction and capable of being observed by the means for observing so as to define said reference position so that the problems associated with convection current jitter are overcome.

  4. Solid-Vapor Sorption Refrigeration Systems

    E-Print Network [OSTI]

    Graebel, W.; Rockenfeller, U.; Kirol, L.

    SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL DR. UWE ROCKENFELLER MR. LANCE KIROL Engineer President Chief Engineer Rocky Research Rocky Research Rocky Research Boulder city, NV Boulder city, NV Boulder City, NV Abstract... Complex compound sorption reactions are ideally suited for use in refrigeration cycles as an economically viable alternative to CFC refrigerants. Complex compound refrigeration provides a number of energy-saving advantages over present refrigeration...

  5. DuPont Chemical Vapor Technical Report

    SciTech Connect (OSTI)

    MOORE, T.L.

    2003-10-03T23:59:59.000Z

    DuPont Safety Resources was tasked with reviewing the current chemical vapor control practices and providing preventive recommendations on best commercial techniques to control worker exposures. The increased focus of the tank closure project to meet the 2024 Tri-Party Agreement (TPA) milestones has surfaced concerns among some CH2MHill employees and other interested parties. CH2MHill is committed to providing a safe working environment for employees and desires to safely manage the tank farm operations using appropriate control measures. To address worker concerns, CH2MHill has chartered a ''Chemical Vapors Project'' to integrate the activities of multiple CH2MHill project teams, and solicit the expertise of external resources, including an independent Industrial Hygiene expert panel, a communications consultant, and DuPont Safety Resources. Over a three-month time period, DuPont worked with CH2MHill ESH&Q, Industrial Hygiene, Engineering, and the independent expert panel to perform the assessment. The process included overview presentations, formal interviews, informal discussions, documentation review, and literature review. DuPont Safety Resources concluded that it is highly unlikely that workers in the tank farms are exposed to chemicals above established standards. Additionally, the conventional and radiological chemistry is understood, the inherent chemical hazards are known, and the risk associated with chemical vapor exposure is properly managed. The assessment highlighted management's commitment to addressing chemical vapor hazards and controlling the associated risks. Additionally, we found the Industrial Hygiene staff to be technically competent and well motivated. The tank characterization data resides in a comprehensive database containing the tank chemical compositions and relevant airborne concentrations.

  6. Vapor-phase heat-transport system

    SciTech Connect (OSTI)

    Hedstrom, J.C.

    1983-01-01T23:59:59.000Z

    A vapor-phase heat-transport system is being tested in one of the passive test cells at Los Alamos. The system consists of one selective-surface collector and a condenser inside a water storage tank. The refrigerant, R-11, can be returned to the collector by gravity or with a pump. Results from several operating configurations are presented, together with a comparison with other passive systems. A new self-pumping concept is presented.

  7. Combined rankine and vapor compression cycles

    DOE Patents [OSTI]

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19T23:59:59.000Z

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  8. High volume fuel vapor release valve

    SciTech Connect (OSTI)

    Gimby, D.R.

    1991-09-03T23:59:59.000Z

    This patent describes a fuel vapor release valve for use in a vehicle fuel system. It comprises a valve housing 10 placed in a specific longitudinal orientation, the valve housing 10 defining an interior cavity 22 having an inlet 20 for admitting fuel vapor and an outlet 14 for discharging such fuel vapor; a valve member 24 positioned in the cavity 22 for movement between an outlet 14 opening position and an outlet 14 closing position, the valve member 24 including a cap member 34 having a seat surface 36 for mating with the outlet 14 and an orifice 42 extending through the cap member 34 providing a passageway from the outlet 14 to the cavity 22, the orifice 42 extending through the cap member 34 providing a passageway from the outlet 14 to the cavity 22, the orifice 42 having a lesser radius than the outlet 14; the valve member 24 further including a plug member 30 engaged with the cap member 34 for movement between an orifice 42 opening position and an orifice 42 closing position; and, a valve housing tilt responsive means for moving the valve member 24 to an outlet 14 and orifice 42 closing position in response to tilting of the valve 10 about its longitudinal axis whereby, upon the return of the valve 10 to its specified longitudinal orientation, the plug member 30 first moves to an orifice 42 opening position and the cap member 34 subsequently moves to an outlet 14 opening position.

  9. Oxidative chemical vapor deposition of semiconducting polymers and their use In organic photovoltaics

    E-Print Network [OSTI]

    Borrelli, David Christopher

    2014-01-01T23:59:59.000Z

    Organic photovoltaics (OPVs) have received significant interest for their potential low cost, high mechanical flexibility, and unique functionalities. OPVs employing semiconducting polymers in the photoactive layer have ...

  10. Microbridge testing of plasma-enhanced chemical-vapor deposited silicon oxide films on silicon wafers

    E-Print Network [OSTI]

    that is typically encountered in applications involving microelectromechanical systems (MEMS.016212 PACS number(s): 05.45.-a, 85.85.+j, 62.25.-g, 47.52.+j I. INTRODUCTION Microelectromechanical systems

  11. Low Temperature Chemical Vapor Deposition of Zirconium Nitride in a Fluidized Bed

    E-Print Network [OSTI]

    Arrieta, Marie

    2012-10-19T23:59:59.000Z

    thick) on uranium-molybdenum (UMo) particulate fuel. Plate-type fuel with U-xMo (x = 3 to 10 wt.%) particle fuel dispersed in an aluminum matrix is under development at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test...

  12. Plasma Enhanced Chemical Vapor Deposition on Living Substrates: Development, Characterization, and Biological Applications

    E-Print Network [OSTI]

    Tsai, Tsung-Chan 1982-

    2012-12-05T23:59:59.000Z

    air and at low temperature was developed using a helium dielectric barrier discharge jet (DBD jet). It was demonstrated that various materials, such as polymeric, metallic, and composite films, can be readily synthesized through this technique. Second...

  13. Towards improved spinnability of chemical vapor deposition generated multi-walled carbon nanotubes

    E-Print Network [OSTI]

    McKee, Gregg Sturdivant Burke

    2008-01-01T23:59:59.000Z

    Solid State Chemistry 177 4394-4398 Lu K. L. , Lago R. M. ,of Solid State Chemistry 177 4394-4398 Coquay P. , De Grave

  14. Chemical vapor deposition and functionalization of fluorocarbon-organosilicon copolymer thin films

    E-Print Network [OSTI]

    Murthy, Shashi Krishna, 1977-

    2003-01-01T23:59:59.000Z

    Neural prostheses are micron-scale integrated circuit devices that are under development for the treatment of brain and spinal cord injuries. A key challenge in the fabrication of these silicon- based devices is the ...

  15. Perfluorooctane Sulfonyl Fluoride as an Initiator in Hot-Filament Chemical Vapor Deposition of Fluorocarbon

    E-Print Network [OSTI]

    Gleason, Karen K.

    of Fluorocarbon Thin Films Hilton G. Pryce Lewis, Jeffrey A. Caulfield, and Karen K. Gleason*, Department pathways available via HFCVD makes it possible to produce polymeric fluorocarbon films spectroscopically

  16. Metalorganic Chemical Vapor Deposition Route to GaN Nanowires with Triangular

    E-Print Network [OSTI]

    Yang, Peidong

    -free environment at atmospheric pressure. TMG was kept cool in a -10 °C temperature bath. Nitrogen, used a total nitrogen flow rate of 250 sccm. These were supplied via a 4-mm i.d. quartz tube. Hydrogen and ammonia sources were supplied via a 22-mm i.d. outer quartz tube at a total flow rate of 155 sccm

  17. A conformal nano-adhesive via initiated chemical vapor deposition for microfluidic devices

    E-Print Network [OSTI]

    Doyle, Patrick S.

    (ethylene terephthalate) (PET), polycarbonate (PC), and poly(tetrafluoro ethylene) (PTFE). Introduction Microfluidic consumption of reagents and analytes, low cost of manufacture, low consumption of power, high throughput

  18. In-situ formation of multiphase electron beam physical vapor deposited barrier coatings for turbine components

    DOE Patents [OSTI]

    Subramanian, Ramesh (Oviedo, FL)

    2001-01-01T23:59:59.000Z

    A turbine component (10), such as a turbine blade, is provided which is made of a metal alloy (22) and a base columnar thermal barrier coating (20) on the alloy surface, where a heat resistant ceramic oxide sheath material (32' or 34') covers the columns (28), and the sheath material is the reaction product of a precursor ceramic oxide sheath material and the base thermal barrier coating material.

  19. Chemical Vapor Deposition Based Synthesis of Carbon Nanotubes and Nanofibers Using a Template Method

    E-Print Network [OSTI]

    of battery electrodes.5,10 These microtubular TiS2 electrodes show higher capacities, lower resistance,19 including electrochemistry.20 The use of metal catalysts such as Ni, Fe, Fe-Cu, and Pt has been, and lower susceptibility to slow electron- transfer kinetics than thin film TiS2 electrodes. In the present

  20. Polymers via chemical vapor deposition and their application to organic photovoltaics

    E-Print Network [OSTI]

    Barr, Miles Clark

    2012-01-01T23:59:59.000Z

    There is emerging interest in the ability to fabricate organic photovoltaics (OPVs) on flexible, lightweight substrates, which could lower the cost of installation and enable new form factors for deployment. However, ...

  1. Volatile organometallic complexes suitable for use in chemical vapor depositions on metal oxide films

    DOE Patents [OSTI]

    Giolando, Dean M.

    2003-09-30T23:59:59.000Z

    Novel ligated compounds of tin, titanium, and zinc are useful as metal oxide CVD precursor compounds without the detriments of extreme reactivity yet maintaining the ability to produce high quality metal oxide coating by contact with heated substrates.

  2. Desktop systems for manufacturing carbon nanotube films by chemical vapor deposition

    E-Print Network [OSTI]

    Kuhn, David S. (David Scott)

    2007-01-01T23:59:59.000Z

    Carbon nanotubes (CNTs) exhibit exceptional electrical, thermal, and mechanical properties that could potentially transform such diverse fields as composites, electronics, cooling, energy storage, and biological sensing. ...

  3. A dual-laser interferometry system for thin film measurements in thermal vapor deposition applications

    E-Print Network [OSTI]

    Yin, Allen Shiping

    2012-01-01T23:59:59.000Z

    Lithography processes harnessing the phase change of the chemically inert carbon dioxide as a resist have been shown as a possible alternative to patterning thin film organic semiconductors and metals. The ability to control ...

  4. In-situ observations during chemical vapor deposition of hexagonal boron nitride on polycrystalline copper

    E-Print Network [OSTI]

    Kidambi, Piran R.; Blume, Raoul; Kling, Jens; Wagner, Jakob B.; Baehtz, Carsten; Weatherup, Robert S.; Schlögl, Robert; Bayer, Bernhard C.; Hofmann, Stephan

    2014-10-20T23:59:59.000Z

    during h-BN CVD process. For experiments with air pre-dosing the dosing was performed post H2 annealing i.e. in between step 2 and step 3 in Figure 1. The ISISS end station of FHI MPG at the BESSY II synchrotron was used for In-situ XPS measurements...

  5. Towards improved spinnability of chemical vapor deposition generated multi-walled carbon nanotubes

    E-Print Network [OSTI]

    McKee, Gregg Sturdivant Burke

    2008-01-01T23:59:59.000Z

    60 2.3.1.3 Unaligned Ceramic Matrix10 wt%. 2.3.1.3 Unaligned Ceramic Matrix Composites Ceramic-ceramic with approximate composition of 55% fluorophlogopite mica in a borosilicate glass matrix,

  6. Oxidative and initiated chemical vapor deposition for application to organic electronics

    E-Print Network [OSTI]

    Im, Sung Gap

    2009-01-01T23:59:59.000Z

    Since the first discovery of polymeric conductors in 1977, the research area of "organic electronics" has grown dramatically. However, methods for forming thin films comprised solely of conductive polymers are limited by ...

  7. Graphene-on-Insulator Transistors Made Using C on Ni Chemical-Vapor Deposition

    E-Print Network [OSTI]

    Keast, Craig L.

    Graphene transistors are made by transferring a thin graphene film grown on Ni onto an insulating SiO[subscript 2] substrate. The properties and integration of these graphene-on-insulator transistors are presented and ...

  8. Researchers develop electrodeposition process to deposit coatings on substrates, eliminate the expensive physical vapor

    E-Print Network [OSTI]

    (CRADA) between NREL and DASS TECH Co., Ltd. of South Korea. Technical Contact: Raghu N. Bhattacharya

  9. Chemical vapor deposition of conjugated polymeric thin films for photonic and electronic applications

    E-Print Network [OSTI]

    Lock, John P

    2005-01-01T23:59:59.000Z

    (cont.) Conjugated polymers have delocalized electrons along the backbone, facilitating electrical conductivity. As thin films, they are integral to organic semiconductor devices emerging in the marketplace, such as flexible ...

  10. Lithium manganese oxide films fabricated by electron beam directed vapor deposition

    E-Print Network [OSTI]

    Wadley, Haydn

    material for high energy den- sity battery applications.7,8 Lithium­transition metal oxide films can.2. After annealing in air at 700 °C, thin films grown with a low jet speed had a cubic spinel structure Li/Li-ion batteries. © 2008 American Vacuum Society. DOI: 10.1116/1.2823488 I. INTRODUCTION Thin film

  11. Optical characterization of InN layers grown by high-pressure chemical vapor deposition

    E-Print Network [OSTI]

    Nabben, Reinhard

    and optical properties of InN films grown on sapphire and GaN/sapphire templates. Results obtained from Raman analyzed in this contribution were grown on GaN/sapphire and sapphire 0001 substrates by HPCVD, utilizing to optical absorption edge estimates obtained from optical transmission spectra analysis. The analysis shows

  12. Parallel Reacting Flow Calculations for Chemical Vapor Deposition Reactor Design 1

    E-Print Network [OSTI]

    Devine, Karen

    , memory, and scalability of distributed memory parallel computers. An unstructured finite element transport from the fluid mechanics and heat transfer. Both works used solution procedures that require the reacting flow model and numerical method and summarize representative calculations using MPSalsa

  13. Chemical Vapor Deposition of Silicon Dioxide by Direct-Current Corona Discharges in Dry Air

    E-Print Network [OSTI]

    Chen, Junhong

    on the high voltage wire. The wire is 100 mm radius tungsten and the wire- to-plate spacing is 1.5 cm parameters and electrode geometry on the production of ozone.(1­8) Recently, the authors developed a fundamental model of the energy distribution of electrons(9,10) and production and distribution of ozone

  14. System and Method for Sealing a Vapor Deposition Source - Energy Innovation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructureProposed Action(Insert DirectiveSynthetic

  15. NREL: Awards and Honors - High-Rate Vapor Transport Deposition for CdTe PV

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Saleshttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifNREL NREL Refines Method

  16. Method and apparatus for concentrating vapors for analysis

    DOE Patents [OSTI]

    Grate, Jay W. (West Richland, WA); Baldwin, David L. (Kennewick, WA); Anheier, Jr., Norman C. (Richland, WA)

    2012-06-05T23:59:59.000Z

    A pre-concentration device and a method are disclosed for concentrating gaseous vapors for analysis. Vapors sorbed and concentrated within the bed of the pre-concentration device are thermally desorbed, achieving at least partial separation of the vapor mixtures. The pre-concentration device is suitable, e.g., for pre-concentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable.

  17. G-Band Vapor Radiometer Profiler (GVRP) Handbook

    SciTech Connect (OSTI)

    Caddeau, MP

    2010-06-23T23:59:59.000Z

    The G-Band Vapor Radiometer Profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.310 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. Channels between 170.0 and 176.0 GHz are particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from the GVRP instrument are therefore especially useful during low-humidity conditions (PWV < 5 mm). In addition to integrated water vapor and liquid water, the GVRP can provide low-resolution vertical profiles of water vapor in very dry conditions.

  18. Method for controlling corrosion in thermal vapor injection gases

    DOE Patents [OSTI]

    Sperry, John S. (Houston, TX); Krajicek, Richard W. (Houston, TX)

    1981-01-01T23:59:59.000Z

    An improvement in the method for producing high pressure thermal vapor streams from combustion gases for injection into subterranean oil producing formations to stimulate the production of viscous minerals is described. The improvement involves controlling corrosion in such thermal vapor gases by injecting water near the flame in the combustion zone and injecting ammonia into a vapor producing vessel to contact the combustion gases exiting the combustion chamber.

  19. Heat Recovery in Distillation by Mechanical Vapor Recompression

    E-Print Network [OSTI]

    Becker, F. E.; Zakak, A. I.

    tower energy requirements can be achieved by mechanical vapor recompression. Three design approaches for heating a distillation tower reboiler by mechanical vapor recompression are presented. The advantages of using a screw compressor are discussed... for lowering energy consumption in the distillation process through various heat recovery techniques. (3-8) One such technique utilizes mechanical vapor recompression. (9-12) The principle of this ap proach involves the use of a compressor to recycle...

  20. Recovery of benzene in an organic vapor monitor

    E-Print Network [OSTI]

    Krenek, Gregory Joel

    1980-01-01T23:59:59.000Z

    solid adsorbents available (silica gel, activated alumina, etc. ), activated charcoal is most frequently utilized. Activated charcoal has retentivity for sorbed vapors several times that of silica gel and it displays a selectivity for organic vapors... (diffusion rate) of the vapor molecules to the sur- face of the adsorbent. The adsorption process determine how effective the adsorbent collects and holds the contam- inant on the surface of the activated charcoal. Recovery of the contaminant from...