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Sample records for silane silicon material

  1. Low cost silicon solar array project silicon materials task: Establishment of the feasibility of a process capable of low-cost, high volume production of silane (step 1) and the pyrolysis of silane to semiconductor-grade silicon (step 2)

    Science.gov (United States)

    Breneman, W. C.; Cheung, H.; Farrier, E. G.; Morihara, H.

    1977-01-01

    A quartz fluid bed reactor capable of operating at temperatures of up to 1000 C was designed, constructed, and successfully operated. During a 30 minute experiment, silane was decomposed within the reactor with no pyrolysis occurring on the reactor wall or on the gas injection system. A hammer mill/roller-crusher system appeared to be the most practical method for producing seed material from bulk silicon. No measurable impurities were detected in the silicon powder produced by the free space reactor, using the cathode layer emission spectroscopic technique. Impurity concentration followed by emission spectroscopic examination of the residue indicated a total impurity level of 2 micrograms/gram. A pellet cast from this powder had an electrical resistivity of 35 to 45 ohm-cm and P-type conductivity.

  2. Hydrogen plasma treatment of silicon dioxide for improved silane deposition.

    Science.gov (United States)

    Gupta, Vipul; Madaan, Nitesh; Jensen, David S; Kunzler, Shawn C; Linford, Matthew R

    2013-03-19

    We describe a method for plasma cleaning silicon surfaces in a commercial tool that removes adventitious organic contamination and enhances silane deposition. As shown by wetting, ellipsometry, and XPS, hydrogen, oxygen, and argon plasmas effectively clean Si/SiO2 surfaces. However, only hydrogen plasmas appear to enhance subsequent low-pressure chemical vapor deposition of silanes. Chemical differences between the surfaces were confirmed via (i) deposition of two different silanes: octyldimethylmethoxysilane and butyldimethylmethoxysilane, as evidenced by spectroscopic ellipsometry and wetting, and (ii) a principal components analysis (PCA) of TOF-SIMS data taken from the different plasma-treated surfaces. AFM shows no increase in surface roughness after H2 or O2 plasma treatment of Si/SiO2. The effects of surface treatment with H2/O2 plasmas in different gas ratios, which should allow greater control of surface chemistry, and the duration of the H2 plasma (complete surface treatment appeared to take place quickly) are also presented. We believe that this work is significant because of the importance of silanes as surface functionalization reagents, and in particular because of the increasing importance of gas phase silane deposition.

  3. Synchrotron-radiation XPS analysis of ultra-thin silane films: Specifying the organic silicon

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Paul M., E-mail: paul.dietrich@yahoo.de [Bundesanstalt für Materialforschung und – prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany); Glamsch, Stephan [Bundesanstalt für Materialforschung und – prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany); Freie Universität Berlin, Institut für Chemie und Biochemie, Fabeckstr. 34/36, 14195 Berlin (Germany); Ehlert, Christopher [Bundesanstalt für Materialforschung und – prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany); Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam (Germany); Lippitz, Andreas [Bundesanstalt für Materialforschung und – prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany); Kulak, Nora [Freie Universität Berlin, Institut für Chemie und Biochemie, Fabeckstr. 34/36, 14195 Berlin (Germany); Unger, Wolfgang E.S. [Bundesanstalt für Materialforschung und – prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany)

    2016-02-15

    Graphical abstract: - Highlights: • A synchrotron-based XPS method to analyze ultra-thin silane films is presented. • Specification and quantification of organic next to inorganic silicon is demonstrated. • Non-destructive chemical depth profiles of the silane monolayers were obtained. - Abstract: The analysis of chemical and elemental in-depth variations in ultra-thin organic layers with thicknesses below 5 nm is very challenging. Energy- and angle-resolved XPS (ER/AR-XPS) opens up the possibility for non-destructive chemical ultra-shallow depth profiling of the outermost surface layer of ultra-thin organic films due to its exceptional surface sensitivity. For common organic materials a reliable chemical in-depth analysis with a lower limit of the XPS information depth z{sub 95} of about 1 nm can be performed. As a proof-of-principle example with relevance for industrial applications the ER/AR-XPS analysis of different organic monolayers made of amino- or benzamidosilane molecules on silicon oxide surfaces is presented. It is demonstrated how to use the Si 2p core-level region to non-destructively depth-profile the organic (silane monolayer) – inorganic (SiO{sub 2}/Si) interface and how to quantify Si species, ranging from elemental silicon over native silicon oxide to the silane itself. The main advantage of the applied ER/AR-XPS method is the improved specification of organic from inorganic silicon components in Si 2p core-level spectra with exceptional low uncertainties compared to conventional laboratory XPS.

  4. Decomposition of silane on tungsten or other materials

    Science.gov (United States)

    Wiesmann, H.J.

    This invention relates to hydrogenated amorphous silicon produced by thermally decomposing silane (SiH/sub 4/) or other gases comprising H and Si, from a W or foil heated to a temperature of about 1400 to 1600/sup 0/C, in a vacuum of about 10-/sup 6/ to 10-/sup 4/ torr. A gaseous mixture is formed of atomic hydrogen and atomic silicon. The gaseous mixture is deposited onto a substrate independent of and outside the source of thermal decomposition. Hydrogenated amorphous silicon is formed. The presence of an ammonia atmosphere in the vacuum chamber enhances the photoconductivity of the hydrogenated amorphous silicon film.

  5. Low cost silicon solar array project: Feasibility of low-cost, high-volume production of silane and pyrolysis of silane to semiconductor-grade silicon

    Science.gov (United States)

    Breneman, W. C.

    1978-01-01

    Silicon epitaxy analysis of silane produced in the Process Development Unit operating in a completely integrated mode consuming only hydrogen and metallurgical silicon resulted in film resistivities of up to 120 ohms cm N type. Preliminary kinetic studies of dichlorosilane disproportionation in the liquid phase have shown that 11.59% SiH4 is formed at equilibrium after 12 minutes contact time at 56 C. The fluid-bed reactor was operated continuously for 48 hours with a mixture of one percent silane in helium as the fluidizing gas. A high silane pyrolysis efficiency was obtained without the generation of excessive fines. Gas flow conditions near the base of the reactor were unfavorable for maintaining a bubbling bed with good heat transfer characteristics. Consequently, a porous agglomerate formed in the lower portion of the reactor. Dense coherent plating was obtained on the silicon seed particles which had remained fluidizied throughout the experiment.

  6. Femtosecond transient absorption spectroscopy of silanized silicon quantum dots

    Science.gov (United States)

    Kuntermann, Volker; Cimpean, Carla; Brehm, Georg; Sauer, Guido; Kryschi, Carola; Wiggers, Hartmut

    2008-03-01

    Excitonic properties of colloidal silicon quantum dots (Si qdots) with mean sizes of 4nm were examined using stationary and time-resolved optical spectroscopy. Chemically stable silicon oxide shells were prepared by controlled surface oxidation and silanization of HF-etched Si qdots. The ultrafast relaxation dynamics of photogenerated excitons in Si qdot colloids were studied on the picosecond time scale from 0.3psto2.3ns using femtosecond-resolved transient absorption spectroscopy. The time evolution of the transient absorption spectra of the Si qdots excited with a 150fs pump pulse at 390nm was observed to consist of decays of various absorption transitions of photoexcited electrons in the conduction band which overlap with both the photoluminescence and the photobleaching of the valence band population density. Gaussian deconvolution of the spectroscopic data allowed for disentangling various carrier relaxation processes involving electron-phonon and phonon-phonon scatterings or arising from surface-state trapping. The initial energy and momentum relaxation of hot carriers was observed to take place via scattering by optical phonons within 0.6ps . Exciton capturing by surface states forming shallow traps in the amorphous SiOx shell was found to occur with a time constant of 4ps , whereas deeper traps presumably localized in the Si-SiOx interface gave rise to exciton trapping processes with time constants of 110 and 180ps . Electron transfer from initially populated, higher-lying surface states to the conduction band of Si qdots (>2nm) was observed to take place within 400 or 700fs .

  7. Suppression of interfacial voids formation during silane (SiH4)-based silicon oxide bonding with a thin silicon nitride capping layer

    Science.gov (United States)

    Lee, Kwang Hong; Bao, Shuyu; Wang, Yue; Fitzgerald, Eugene A.; Seng Tan, Chuan

    2018-01-01

    The material properties and bonding behavior of silane-based silicon oxide layers deposited by plasma-enhanced chemical vapor deposition were investigated. Fourier transform infrared spectroscopy was employed to determine the chemical composition of the silicon oxide films. The incorporation of hydroxyl (-OH) groups and moisture absorption demonstrates a strong correlation with the storage duration for both as-deposited and annealed silicon oxide films. It is observed that moisture absorption is prevalent in the silane-based silicon oxide film due to its porous nature. The incorporation of -OH groups and moisture absorption in the silicon oxide films increase with the storage time (even in clean-room environments) for both as-deposited and annealed silicon oxide films. Due to silanol condensation and silicon oxidation reactions that take place at the bonding interface and in the bulk silicon, hydrogen (a byproduct of these reactions) is released and diffused towards the bonding interface. The trapped hydrogen forms voids over time. Additionally, the absorbed moisture could evaporate during the post-bond annealing of the bonded wafer pair. As a consequence, defects, such as voids, form at the bonding interface. To address the problem, a thin silicon nitride capping film was deposited on the silicon oxide layer before bonding to serve as a diffusion barrier to prevent moisture absorption and incorporation of -OH groups from the ambient. This process results in defect-free bonded wafers.

  8. Silane-based hybrid materials for biomedical applications

    NARCIS (Netherlands)

    Kros, A.; Jansen, J.A.; Holder, S.J.; Nolte, R.J.M.; Sommerdijk, N.A.J.M.

    2002-01-01

    In this paper, the preparation of different hybrid silane materials is presented and their possible use in biomedical applications is discussed. The first example describes the development of biocompatible coatings based on sol-gel silicates, which can be used as a protective coating for implantable

  9. Formation and Characterization of Stacked Nanoscale Layers of Polymers and Silanes on Silicon Surfaces

    Science.gov (United States)

    Ochoa, Rosie; Davis, Brian; Conley, Hiram; Hurd, Katie; Linford, Matthew R.; Davis, Robert C.

    2008-10-01

    Chemical surface patterning at the nanoscale is a critical component of chemically directed assembly of nanoscale devices or sensitive biological molecules onto surfaces. Complete and consistent formation of nanoscale layers of silanes and polymers is a necessary first step for chemical patterning. We explored methods of silanizing silicon substrates for the purpose of functionalizing the surfaces. The chemical functionalization, stability, flatness, and repeatability of the process was characterized by use of ellipsometry, water contact angle, and Atomic Force Microscopy (AFM). We found that forming the highest quality functionalized surfaces was accomplished through use of chemical vapor deposition (CVD). Specifically, surfaces were plasma cleaned and hydrolyzed before the silane was applied. A polymer layer less then 2 nm in thickness was electrostatically bound to the silane layer. The chemical functionalization, stability, flatness, and repeatability of the process was also characterized for the polymer layer using ellipsometry, water contact angle, and AFM.

  10. Amorphous silicon prepared from silane-hydrogen mixture

    International Nuclear Information System (INIS)

    Pietruszko, S.M.

    1982-09-01

    Amorphous silicon films prepared from a d.c. discharge of 10% SiH 4 - 90% H 2 mixture are found to have properties similar to those made from 100% SiH 4 . These films are found to be quite stable against prolonged light exposure. The effect of nitrogen on the properties of these films was investigated. It was found that instead of behaving as a classical donor, nitrogen introduces deep levels in the material. Field effect experiments on a-Si:H films at the bottom (film-substrate interface) and the top (film-vacuum interface) of the film are also reported. (author)

  11. Visible photoluminescence from hydrogenated silicon particles suspended in a silane plasma

    International Nuclear Information System (INIS)

    Courteille, C.; Dorier, J.L.; Dutta, J.; Hollenstein, C.; Howling, A.A.; Stoto, T.

    1994-09-01

    Visible photoluminescence at room temperature has been observed in amorphous hydrogenated silicon particulates during their formation in a silane radio-frequency plasma. Oxygen injection along with mass spectrometry measurements demonstrate that oxygen has no influence on the photoluminescence. The appearance of visible photoluminescence coincides with a particle agglomeration phase as shown by laser light scattering experiments, and electron microscopy shows silicon nanocrystals within these particulates. These observations of visible photoluminescence are consistent with the model of quantum confinement in the silicon nanocrystals. (author) 5 figs., 45 refs

  12. Atomic Layer Deposition of Silicon Nitride from Bis(tert-butylamino)silane and N2 Plasma.

    Science.gov (United States)

    Knoops, Harm C M; Braeken, Eline M J; de Peuter, Koen; Potts, Stephen E; Haukka, Suvi; Pore, Viljami; Kessels, Wilhelmus M M

    2015-09-09

    Atomic layer deposition (ALD) of silicon nitride (SiNx) is deemed essential for a variety of applications in nanoelectronics, such as gate spacer layers in transistors. In this work an ALD process using bis(tert-butylamino)silane (BTBAS) and N2 plasma was developed and studied. The process exhibited a wide temperature window starting from room temperature up to 500 °C. The material properties and wet-etch rates were investigated as a function of plasma exposure time, plasma pressure, and substrate table temperature. Table temperatures of 300-500 °C yielded a high material quality and a composition close to Si3N4 was obtained at 500 °C (N/Si=1.4±0.1, mass density=2.9±0.1 g/cm3, refractive index=1.96±0.03). Low wet-etch rates of ∼1 nm/min were obtained for films deposited at table temperatures of 400 °C and higher, similar to that achieved in the literature using low-pressure chemical vapor deposition of SiNx at >700 °C. For novel applications requiring significantly lower temperatures, the temperature window from room temperature to 200 °C can be a solution, where relatively high material quality was obtained when operating at low plasma pressures or long plasma exposure times.

  13. Effect of silane/hydrogen ratio on microcrystalline silicon thin films by remote inductively coupled plasma

    Science.gov (United States)

    Guo, Y. N.; Wei, D. Y.; Xiao, S. Q.; Huang, S. Y.; Zhou, H. P.; Xu, S.

    2013-05-01

    Hydrogenated microcrystalline silicon (μc-Si:H) thin films were prepared by remote low frequency inductively coupled plasma (ICP) chemical vapor deposition system, and the effect of silane/hydrogen ratio on the microstructure and electrical properties of μc-Si:H films was systematically investigated. As silane/hydrogen ratio increases, the crystalline volume fraction Fc decreases and the ratio of the intensity of (220) peak to that of (111) peak drops as silane flow rate is increased. The FTIR result indicates that the μc-Si:H films prepared by remote ICP have a high optical response with a low hydrogen content, which is in favor of reducing light-induced degradation effect. Furthermore, the processing window of the phase transition region for remote ICP is much wider than that for typical ICP. The photosensitivity of μc-Si:H films can exceed 100 at the transition region and this ensures the possibility of the fabrication of microcrystalline silicon thin film solar cells with a open-circuit voltage of about 700 mV.

  14. Protein attachment to silane-functionalized porous silicon: A comparison of electrostatic and covalent attachment.

    Science.gov (United States)

    Baranowska, Malgorzata; Slota, Agata J; Eravuchira, Pinkie J; Alba, Maria; Formentin, Pilar; Pallarès, Josep; Ferré-Borrull, Josep; Marsal, Lluís F

    2015-08-15

    Porous silicon (pSi) is a prosperous biomaterial, biocompatible, and biodegradable. Obtaining regularly functionalized pSi surfaces is required in many biotechnology applications. Silane-PEG-NHS (triethoxysilane-polyethylene-glycol-N-hydroxysuccinimide) is useful for single-molecule studies due to its ability to attach to only one biomolecule. We investigate the functionalization of pSi with silane-PEG-NHS and compare it with two common grafting agents: APTMS (3-aminopropylotrimethoxysilane) as electrostatic linker, and APTMS modified with glutaraldehyde as covalent spacer. We show the arrangement of two proteins (collagen and bovine serum albumin) as a function of the functionalization and of the pore size. FTIR is used to demonstrate correct functionalization while fluorescence confocal microscopy reveals that silane-PEG-NHS results in a more uniform protein distribution. Reflection interference spectroscopy (RIfS) is used to estimate the attachment of linker and proteins. The results open a way to obtain homogenous chemical modified silicon supports with a great value in biosensing, drug delivery and cell biology. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Flat-plate solar array project. Volume 2: Silicon material

    Science.gov (United States)

    Lutwack, R.

    1986-10-01

    The goal of the Silicon Material Task, a part of the Flat Plate Solar Array (FSA) Project, was to develop and demonstate the technology for the low cost production of silicon of suitable purity to be used as the basic material for the manufacture of terrestrial photovoltaic solar cells. Summarized are 11 different processes for the production of silicon that were investigated and developed to varying extent by industrial, university, and Government researchers. The silane production section of the Union Carbide Corp. (UCC) silane process was developed completely in this program. Coupled with Siemens-type chemical vapor deposition reactors, the process was carried through the pilot stage. The overall UCC process involves the conversion of metallurgical-grade silicon to silane followed by decomposition of the silane to purified silicon. The other process developments are described to varying extents. Studies are reported on the effects of impurities in silicon on both silicon-material properties and on solar cell performance. These studies on the effects of impurities yielded extensive information and models for relating specific elemental concentrations to levels of deleterious effects.

  16. Flat-plate solar array project. Volume 2: Silicon material

    Science.gov (United States)

    Lutwack, R.

    1986-01-01

    The goal of the Silicon Material Task, a part of the Flat Plate Solar Array (FSA) Project, was to develop and demonstate the technology for the low cost production of silicon of suitable purity to be used as the basic material for the manufacture of terrestrial photovoltaic solar cells. Summarized are 11 different processes for the production of silicon that were investigated and developed to varying extent by industrial, university, and Government researchers. The silane production section of the Union Carbide Corp. (UCC) silane process was developed completely in this program. Coupled with Siemens-type chemical vapor deposition reactors, the process was carried through the pilot stage. The overall UCC process involves the conversion of metallurgical-grade silicon to silane followed by decomposition of the silane to purified silicon. The other process developments are described to varying extents. Studies are reported on the effects of impurities in silicon on both silicon-material properties and on solar cell performance. These studies on the effects of impurities yielded extensive information and models for relating specific elemental concentrations to levels of deleterious effects.

  17. Effect of silane dilution on intrinsic stress in glow discharge hydrogenated amorphous silicon films

    Science.gov (United States)

    Harbison, J. P.; Williams, A. J.; Lang, D. V.

    1984-02-01

    Measurements of the intrinsic stress in hydrogenated amorphous silicon (a-Si : H) films grown by rf glow discharge decomposition of silane diluted to varying degrees in argon are presented. Films are found to grow under exceedingly high compressive stress. Low values of macroscopic film density and low stress values are found to correlate with high growth rate. An abrupt drop in stress occurs between 2 and 3% silane at precisely the point where columnar growth morphology appears. No corresponding abrupt change is noted in density, growth rate, or plasma species concentrations as determined by optical emissioin spectroscopy. Finally a model of diffusive incorporation of hydrogen or some gaseous impurity during growth into the bulk of the film behind the growing interface is proposed to explain the results.

  18. Surface modification of silicon carbide with silane coupling agent and hexadecyl iodiele

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Xujing, E-mail: shangxujing@tju.edu.cn; Zhu, Yumei, E-mail: zymtju@163.com; Li, Zhihong, E-mail: lzhtju@163.com

    2017-02-01

    Highlights: • A novel universal method was performed to enhance hydrophobicity of SiC powder. • The modification effects of KH550 and KH590 were compared and the optimum reaction parameters were established. • Hexadecyl iodiele was successfully grafted on the surface of SiC-KH590 powder. • Surface changes on SiC powder before and after modification were analyzed via FTIR, XPS, SEM. • The related reaction mechanisms were discussed. - Abstract: In this paper, two kinds of silane coupling agents, namely 3-aminopropyl triethoxysilane (KH550) and 3-mercaptopropyl trimethoxysilane (KH590), were adopted as preliminary modifiers to improve the hydrophobic surface properties of silicon carbide (SiC) powder for the first step. The factors that influence the modification effects were investigated by measuring the contact angle. The results showed that KH590 has a better effect than KH550 for the hydrophobic modification of SiC, and the contact angle improved most after SiC powder was reacted with 0.3 g KH590 at 75 °C in aqueous/alcohol solution for 4 h. On account of further enhancement of hydrophobicity, the study was focused on utilizing nucleophilic substitution between KH590 and hexadecyl iodiele to extend the length of alkyl chain. Compared with using KH590 alone, SiC powder modified by KH590 and hexadecyl iodiele showed better water resistance with an increase of contact angle from 106.8° to 127.5°. The Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectra (XPS) as well as X-ray diffraction (XRD) analysis results showed that KH550/KH590 and hexadecyl iodiele can be covalently bonded to the surface of SiC powder without altering its crystal configuration. This methodology may provide a new way of the modification of inorganic materials in further.

  19. Thermal degradation mechanism of addition-cure liquid silicone rubber with urea-containing silane

    International Nuclear Information System (INIS)

    Fang, Weizhen; Zeng, Xingrong; Lai, Xuejun; Li, Hongqiang; Chen, Wanjuan; Zhang, Yajun

    2015-01-01

    Highlights: • The urea-containing silane was incorporated into addition-cure liquid silicone rubber (ALSR) via hydrosilylation reaction. • The thermal stability of the ALSR was improved by DEUPAS both in nitrogen and air • The TG–FTIR of evolved gases during degradation was performed. • The possible degradation mechanism of the ALSR samples was proposed. - Abstract: The reactive urea-containing silane, (γ-diethylureidopropyl) allyloxyethoxysilane (DEUPAS), was synthesized by the trans-etherification reaction. The chemical structure was characterized by Fourier transform infrared spectrometry (FTIR) and 1 H nuclear magnetic resonance spectrometry ( 1 H NMR). Subsequently, DEUPAS was incorporated into addition-cure liquid silicone rubber (ALSR) via hydrosilylation reaction. The thermal stability of the ALSR samples was investigated by thermogravimetry (TG) and thermogravimetry–Fourier transform infrared spectrometry (TG–FTIR). When DEUPAS was incorporated, the temperature of 10% weight loss and 20% weight loss under air atmosphere were respectively increased by 31 °C and 60 °C compared with those of the ALSR without DEUPAS. Meanwhile, the residual weight at 800 °C increased from 33.5% to 58.7%. It was found that the striking enhancement in thermal stability of the ALSR samples was likely attributed to the decomposition of the urea groups to isocyanic acid, which reacted with hydroxyl groups to inhibit the unzipping depolymerization

  20. Thermal degradation mechanism of addition-cure liquid silicone rubber with urea-containing silane

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Weizhen; Zeng, Xingrong, E-mail: psxrzeng@gmail.com; Lai, Xuejun; Li, Hongqiang; Chen, Wanjuan; Zhang, Yajun

    2015-04-10

    Highlights: • The urea-containing silane was incorporated into addition-cure liquid silicone rubber (ALSR) via hydrosilylation reaction. • The thermal stability of the ALSR was improved by DEUPAS both in nitrogen and air • The TG–FTIR of evolved gases during degradation was performed. • The possible degradation mechanism of the ALSR samples was proposed. - Abstract: The reactive urea-containing silane, (γ-diethylureidopropyl) allyloxyethoxysilane (DEUPAS), was synthesized by the trans-etherification reaction. The chemical structure was characterized by Fourier transform infrared spectrometry (FTIR) and {sup 1}H nuclear magnetic resonance spectrometry ({sup 1}H NMR). Subsequently, DEUPAS was incorporated into addition-cure liquid silicone rubber (ALSR) via hydrosilylation reaction. The thermal stability of the ALSR samples was investigated by thermogravimetry (TG) and thermogravimetry–Fourier transform infrared spectrometry (TG–FTIR). When DEUPAS was incorporated, the temperature of 10% weight loss and 20% weight loss under air atmosphere were respectively increased by 31 °C and 60 °C compared with those of the ALSR without DEUPAS. Meanwhile, the residual weight at 800 °C increased from 33.5% to 58.7%. It was found that the striking enhancement in thermal stability of the ALSR samples was likely attributed to the decomposition of the urea groups to isocyanic acid, which reacted with hydroxyl groups to inhibit the unzipping depolymerization.

  1. Analysis of structure and defects in thin silicon films deposited from hydrogen diluted silane

    International Nuclear Information System (INIS)

    Elzakker, G. van; Nadazdy, V.; Tichelaar, F.D.; Metselaar, J.W.; Zeman, M.

    2006-01-01

    Thin silicon layers have been deposited from silane diluted with hydrogen. The dilution ratio R (R = [H 2 ]/[SiH 4 ]) has been varied between R = 0 and R = 40. The structural properties of Si:H films have been studied using transmission electron microscopy imaging and Raman spectroscopy. The phase evolution from the amorphous phase into the mixed and eventually microcrystalline phase strongly depends on the hydrogen dilution. The initiation of the microcrystalline growth occurs between R = 20 and R = 25. The phase transition becomes more abrupt with increasing hydrogen dilution. Optoelectronic properties of the layers have been determined. Increasing hydrogen dilution results in films with increasing effective defect density and Urbach energy, which is related to inhomogeneous growth. The charge deep-level transient spectroscopy technique (Q-DLTS) was applied for the first time on hydrogen diluted thin silicon films in order to investigate the energy distribution of the defect states in these layers as a function of the dilution ratio R. The Q-DLTS spectra indicate a difference in defect-state distribution when the films evolve from the amorphous phase into the microcrystalline phase

  2. Synergistic effect and mechanism of platinum catalyst and nitrogen-containing silane on the thermal stability of silicone rubber

    International Nuclear Information System (INIS)

    Chen, Wanjuan; Zeng, Xingrong; Lai, Xuejun; Li, Hongqiang; Fang, Weizhen; Liu, Tian

    2016-01-01

    Highlights: • Platinum (Pt) and nitrogen-containing silane (NS) were introduced into silicone rubber. • The thermal stability was improved by Pt/NS both under nitrogen and air atmosphere. • The TG-FTIR of evolved gases during degradation was performed. • The synergistic effect and mechanism of Pt and NS were proposed. - Abstract: Platinum (Pt) catalyst and nitrogen-containing silane (NS) were introduced to improve the thermal stability of silicone rubber. The effects of Pt and NS on thermal stability and degradation mechanism of silicone rubber were investigated by thermogravimetry (TG), thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDXS) and Fourier transform infrared spectrometry (FTIR). A significant synergism was found between Pt and NS for improving the thermal stability of silicone rubber. When 6.67 ppm of Pt and 1.4 phr of NS were introduced, the temperature of 10% and 20% weight loss under nitrogen atmosphere were respectively increased by 36 °C and 119 °C. Meanwhile, the residue weight at 900 °C was doubled to 68% in the presence of Pt/NS. The synergistic mechanism might be that the nitrogen atom coordinated with Pt and improved the catalytic efficiency of Pt. Additionally, NS preserved the catalytic activity of Pt under air atmosphere. Hence, Pt/NS efficiently catalyzed thermal crosslinking and suppressed degradation of silicone chains. Moreover, it revealed that the presence of Pt/NS protected silicone chains from oxidation. Thus, the unzipping depolymerization by silanol groups was reduced significantly.

  3. Synergistic effect and mechanism of platinum catalyst and nitrogen-containing silane on the thermal stability of silicone rubber

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wanjuan; Zeng, Xingrong, E-mail: psxrzeng@gmail.com; Lai, Xuejun; Li, Hongqiang; Fang, Weizhen; Liu, Tian

    2016-05-20

    Highlights: • Platinum (Pt) and nitrogen-containing silane (NS) were introduced into silicone rubber. • The thermal stability was improved by Pt/NS both under nitrogen and air atmosphere. • The TG-FTIR of evolved gases during degradation was performed. • The synergistic effect and mechanism of Pt and NS were proposed. - Abstract: Platinum (Pt) catalyst and nitrogen-containing silane (NS) were introduced to improve the thermal stability of silicone rubber. The effects of Pt and NS on thermal stability and degradation mechanism of silicone rubber were investigated by thermogravimetry (TG), thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDXS) and Fourier transform infrared spectrometry (FTIR). A significant synergism was found between Pt and NS for improving the thermal stability of silicone rubber. When 6.67 ppm of Pt and 1.4 phr of NS were introduced, the temperature of 10% and 20% weight loss under nitrogen atmosphere were respectively increased by 36 °C and 119 °C. Meanwhile, the residue weight at 900 °C was doubled to 68% in the presence of Pt/NS. The synergistic mechanism might be that the nitrogen atom coordinated with Pt and improved the catalytic efficiency of Pt. Additionally, NS preserved the catalytic activity of Pt under air atmosphere. Hence, Pt/NS efficiently catalyzed thermal crosslinking and suppressed degradation of silicone chains. Moreover, it revealed that the presence of Pt/NS protected silicone chains from oxidation. Thus, the unzipping depolymerization by silanol groups was reduced significantly.

  4. Magnesium silicide production and silane synthesis on its basis

    International Nuclear Information System (INIS)

    Taurbaev, T.I.; Mukashev, F.A.; Manakov, S.M.; Francev, U.V.; Kalblanbekov, B.M.; Akhter, P.; Abbas, M.; Hussain, A.

    2003-01-01

    We had developed an alternative method of production of magnesium silicide with use of ferroalloys of silicon. Magnesium silicide is raw material for silane synthesis. The essence of the method consist of sintering FS -75 (ferrosilicium with 75 % of silicon and 25 % of iron, made by ferroalloy factories) with metal magnesium at temperature of 650 deg. C. The X-ray analysis has shown formation of magnesium silicide. That is further used for synthesis of silane. The output of silane is 60 % in respect of the contents of silicon. After removing the water vapors the mass-spectrometer analysis has estimated the purity of silane as 99.95 % with no detection of phosphine and diborane. (author)

  5. Low Cost Solar Array Project. Feasibility of the silane process for producing semiconductor-grade silicon. Final report, October 1975-March 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The commercial production of low-cost semiconductor-grade silicon is an essential requirement of the JPL/DOE (Department of Energy) Low-Cost Solar Array (LSA) Project. A 1000-metric-ton-per-year commercial facility using the Union Carbide Silane Process will produce molten silicon for an estimated price of $7.56/kg (1975 dollars, private financing), meeting the DOE goal of less than $10/kg. Conclusions and technology status are reported for both contract phases, which had the following objectives: (1) establish the feasibility of Union Carbide's Silane Process for commercial application, and (2) develop an integrated process design for an Experimental Process System Development Unit (EPSDU) and a commercial facility, and estimate the corresponding commercial plant economic performance. To assemble the facility design, the following work was performed: (a) collection of Union Carbide's applicable background technology; (b) design, assembly, and operation of a small integrated silane-producing Process Development Unit (PDU); (c) analysis, testing, and comparison of two high-temperature methods for converting pure silane to silicon metal; and (d) determination of chemical reaction equilibria and kinetics, and vapor-liquid equilibria for chlorosilanes.

  6. Low Cost Silicon Solar Array Project. Feasibility of Low-cost, High-volume Production of Silane and Pyrolysis of Silane to Semiconductor-grade Silicon

    Science.gov (United States)

    Breneman, W. C.; Farrier, E. G.; Morihara, H.

    1978-01-01

    The presence of copper promotes a more rapid approach to the steady stete operating condition and results in a more consistent reactor effluent composition. The average kinetic and equilibrium yield are unchanged. Incoloy has been identified as the preferred choice of material of construction for the hydrogenation reactor although certain metallurgical changes were noted in samples exposed to the H2/HCl atmosphere at 500 C which indicate the need for more testing.

  7. Synthesis of silicon nanocrystals in silane plasmas for nanoelectronics and large area electronic devices

    International Nuclear Information System (INIS)

    Roca i Cabarrocas, P; Nguyen-Tran, Th; Djeridane, Y; Abramov, A; Johnson, E; Patriarche, G

    2007-01-01

    The synthesis of silicon nanocrystals in standard radio-frequency glow discharge systems is studied with respect to two main objectives: (i) the production of devices based on quantum size effects associated with the small dimensions of silicon nanocrystals and (ii) the synthesis of polymorphous and polycrystalline silicon films in which silicon nanocrystals are the elementary building blocks. In particular we discuss results on the mechanisms of nanocrystal formation and their transport towards the substrate. We found that silicon nanocrystals can contribute to a significant fraction of deposition (50-70%) and that they can be positively charged. This has a strong influence on their deposition because positively charged nanocrystals will be accelerated towards the substrate with energy of the order of the plasma potential. However, the important parameter with respect to the deposition of charged nanocrystals is not the accelerating voltage but the energy per atom and thus a doubling of the diameter will result in a decrease in the energy per atom by a factor of 8. To leverage this geometrical advantage we propose the use of more electronegative gases, which may have a strong effect on the size and charge distribution of the nanocrystals. This is illustrated in the case of deposition from silicon tetrafluoride plasmas in which we observe low-frequency plasma fluctuations, associated with successive generations of nanocrystals. The contribution of larger nanocrystals to deposition results in a lower energy per deposited atom and thus polycrystalline films

  8. Antifungal, optical, and mechanical properties of polymethylmethacrylate material incorporated with silanized zinc oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Kamonkhantikul K

    2017-03-01

    Full Text Available Krid Kamonkhantikul,1 Mansuang Arksornnukit,1 Hidekazu Takahashi2 1Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand; 2Oral Biomaterials Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan Background: Fungal infected denture, which is typically composed of polymethylmethacrylate (PMMA, is a common problem for a denture wearer, especially an elderly patient with limited manual dexterity. Therefore, increasing the antifungal effect of denture by incorporating surface modification nanoparticles into the PMMA, while retaining its mechanical properties, is of interest. Aim of the study: This study aimed to evaluate antifungal, optical, and mechanical properties of heat-cured PMMA incorporated with different amounts of zinc oxide nanoparticles (ZnOnps with or without methacryloxypropyltrimethoxysilane modification. Materials and methods: Specimens made from heat-cured PMMA containing 1.25, 2.5, and 5% (w/w nonsilanized (Nosi or silanized (Si ZnOnps were evaluated. Specimens without filler served as control. The fungal assay was performed placing a Candida albicans suspension on the PMMA surface for 2 h, then Sabouraud Dextrose Broth was added, and growth after 24 h was determined by counting colony forming units on agar plates. A spectrophotometer was used to measure the color in L* (brightness, a* (red-green, b* (yellow-blue and opacity of the experimental groups. Flexural strength and flexural modulus were determined using a three-point bending test on universal testing machine after 37°C water storage for 48 h and 1 month. Results: The antifungal, optical, and mechanical properties of the PMMA incorporated with ZnOnps changed depending on the amount. With the same amount of ZnOnps, the silanized groups demonstrated a greater reduction in C. albicans compared with the Nosi groups. The color difference (ΔE and opacity of the Nosi groups were

  9. Synthesis of silane and silicon in a non-equilibrium plasma jet

    Science.gov (United States)

    Calcote, H. F.; Felder, W.

    1977-01-01

    The feasibility of using a non-equilibrium hydrogen plasma jet as a chemical synthesis tool was investigated. Four possible processes were identified for further study: (1) production of polycrystalline silicon photovoltaic surfaces, (2) production of SiHCl3 from SiCl4, (3) production of SiH4 from SiHCl3, and (4) purification of SiCl4 by metal impurity nucleation. The most striking result was the recognition that the strongly adhering silicon films, amorphous or polycrystalline, produced in our studies could be the basis for preparing a photovoltaic surface directly; this process has potential advantages over other vapor deposition processes.

  10. Hydrophobic perfluoro-silane functionalization of porous silicon photoluminescent films and particles

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, C.; Laplace, P.; Gallach-Pérez, D.; Pellacani, P.; Martín-Palma, R.J. [Departamento de Física Aplicada e Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049, Madrid (Spain); Torres-Costa, V. [Departamento de Física Aplicada e Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049, Madrid (Spain); Centro de Microanálisis de Materiales, Universidad Autónoma de Madrid, 28049, Madrid (Spain); Ceccone, G. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020, Ispra (Italy); Manso Silván, M., E-mail: miguel.manso@uam.es [Departamento de Física Aplicada e Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049, Madrid (Spain)

    2016-09-01

    Highlights: • Hydrophobic functionalization of porous silicon structures. • Perfluorooctyl group binding confirmed by XPS. • Improved stability face to extreme oxidation conditions. • Perfluorooctyl functionalization compatible with photoluminescence of porous silicon particles. - Abstract: Luminescent structures based on semiconductor quantum dots (QDs) are increasingly used in biomolecular assays, cell tracking systems, and in-vivo diagnostics devices. In this work we have carried out the functionalization of porous silicon (PSi) luminescent structures by a perfluorosilane (Perfluoro-octyltriethoxysilane, PFOS) self assembly. The PFOS surface binding (traced by X-ray photoelectron spectroscopy) and photoluminescence efficiency were analyzed on flat model PSi. Maximal photoluminescence intensity was obtained from PSi layers anodized at 110 mA/cm{sup 2}. Resistance to hydroxylation was assayed in H{sub 2}O{sub 2}:ethanol solutions and evidenced by water contact angle (WCA) measurements. PFOS-functionalized PSi presented systematically higher WCA than untreated PSi. The PFOS functionalization was found to slightly improve the aging of the PSi particles in water giving rise to particles with longer luminescent life. Confirmation of PFOS binding to PSi particles was derived from FTIR spectra and the preservation of luminescence was observed by fluorescence microscopy. Such functionalization opens the possibility of promoting hydrophobic-hydrophobic interactions between biomolecules and fluorescent QD structures, which may enlarge their biomedical applications catalogue.

  11. Silane Modification of Cellulose Acetate Dense Films as Materials for Acid Gas Removal

    KAUST Repository

    Achoundong, Carine S. K.

    2013-07-23

    The modification of cellulose acetate (CA) films via grafting of vinyltrimethoxysilane (VTMS) to -OH groups, with subsequent condensation of hydrolyzed methoxy groups on the silane to form a polymer network is presented. The technique is referred to as GCV-modification. The modified material maintains similar H2S/CH4 and CO2/CH 4 selectivities compared to the unmodified material; however the pure CO2 and H2S permeabilities are 139 and 165 barrers, respectively, which are more than an order of magnitude higher than the neat polymer. The membranes were tested at feed pressures of up to 700 psia in a ternary 20 vol. %H2S/20 vol. % CO2/60 vol. % CH 4 mixture. Even under aggressive feed conditions, GCV-modified CA showed comparable selectivities and significantly higher permeabilities. Furthermore, GCV-modified membrane had a lower Tg, lower crystallinity, and higher flexibility than neat CA. The higher flexibility is due to the vinyl substituent provided by VTMS, thereby reducing brittleness, which could be helpful in an asymmetric membrane structure. © 2013 American Chemical Society.

  12. Silane Modification of Cellulose Acetate Dense Films as Materials for Acid Gas Removal

    KAUST Repository

    Achoundong, Carine S. K.; Bhuwania, Nitesh; Burgess, Steven K.; Karvan, Oguz; Johnson, Justin R.; Koros, William J.

    2013-01-01

    The modification of cellulose acetate (CA) films via grafting of vinyltrimethoxysilane (VTMS) to -OH groups, with subsequent condensation of hydrolyzed methoxy groups on the silane to form a polymer network is presented. The technique is referred to as GCV-modification. The modified material maintains similar H2S/CH4 and CO2/CH 4 selectivities compared to the unmodified material; however the pure CO2 and H2S permeabilities are 139 and 165 barrers, respectively, which are more than an order of magnitude higher than the neat polymer. The membranes were tested at feed pressures of up to 700 psia in a ternary 20 vol. %H2S/20 vol. % CO2/60 vol. % CH 4 mixture. Even under aggressive feed conditions, GCV-modified CA showed comparable selectivities and significantly higher permeabilities. Furthermore, GCV-modified membrane had a lower Tg, lower crystallinity, and higher flexibility than neat CA. The higher flexibility is due to the vinyl substituent provided by VTMS, thereby reducing brittleness, which could be helpful in an asymmetric membrane structure. © 2013 American Chemical Society.

  13. Charged particle detectors based on high quality amorphous silicon deposited with hydrogen or helium dilution of silane

    International Nuclear Information System (INIS)

    Hong, Wan-Shick; Drewery, J.S.; Jing, Tao; Lee, Hyoung-Koo; Kaplan, S.N.; Perez-Mendez, V.; Mireshghi, Ali; Kitsuno, Yu

    1994-11-01

    Electrical transport properties of the authors PECVD a-Si:H material has been improved by using hydrogen and/or helium dilution of silane and lower substrate temperature for deposition. For hydrogen-diluted material they have measured electron and hole mobilities ∼ 4 times larger, and μτ values 2-3 times higher than for their standard a-Si:H. The density of ionized dangling bonds (N D *) also showed a factor of 5-10 improvement. Due to its higher conductivity, the improved a- Si:H material is more suitable than conventional a-Si:H for TFT applications. However, it is difficult to make thick layers by H-dilution because of high internal stress. On the other hand, thick detectors can be made at a faster rate and lower stress by low temperature deposition with He-dilution and subsequent annealing. The internal stress, which causes substrate bending and delamination, was reduced by a factor of 4 to ∼90 MPa, while the electronic quality was kept as good as that of the standard material. By this technique 35 μm-thick n-i-p diodes were made without significant substrate bending, and the electronic properties, such as electron mobility and ionized dangling bond density, were suitable for detecting minimum ionizing particles

  14. Charged particle detectors based on high quality amorphous silicon deposited with hydrogen or helium dilution of silane

    International Nuclear Information System (INIS)

    Hong, W.S.; Drewery, J.S.; Jing, T.; Lee, H.; Kaplan, S.N.; Perez-Mendez, V.; Kitsuno, Y.

    1995-01-01

    Electrical transport properties of the PECVD a-Si:H material has been improved by using hydrogen and/or helium dilution of silane and lower substrate temperature for deposition. For hydrogen-diluted material the authors measured electron and hole mobilities ∼4 times larger, and microτ values 2--3 times higher than for the standard a-Si:H. The density of ionized dangling bonds (N D *) also showed a factor of 5--10 improvement. Due to its higher conductivity, the improved a-Si:H material is more suitable than conventional a-Si:H for TFT applications. However, it is difficult to make thick layers by H-dilution because of high internal stress. On the other hand, thick detectors can be made at a faster rate and lower stress by low temperature deposition with He-dilution and subsequent annealing. The internal stress, which causes substrate bending and delamination, was reduced by a factor of 4 to ∼90 MPa, while the electronic quality was kept as good as that of the standard material. By this technique 35 microm-thick n-i-p diodes were made without significant substrate bending, and the electronic properties, such as electron mobility and ionized dangling bond density, were suitable for detecting minimum ionizing particles

  15. Effects of three silane primers and five adhesive agents on the bond strength of composite material for a computer-aided design and manufacturing system.

    Science.gov (United States)

    Shinohara, Ayano; Taira, Yohsuke; Sakihara, Michino; Sawase, Takashi

    2018-01-01

    Objective The objective of this study was to evaluate the effects of combinations of silane primers and adhesive agents on the bond strength of a composite block for a computer-aided design and manufacturing system. Material and Methods Three silane primers [Clearfil Ceramic Primer (CP), Super-Bond PZ Primer (PZ), and GC Ceramic Primer II (GP)] were used in conjunction with five adhesive agents [G-Premio Bond (P-Bond), Repair Adhe Adhesive (R-Adhesive), Super-Bond D-Liner Dual (SB-Dual), Super-Bond C&B (SB-Self), and SB-Dual without tributylborane derivative (SB-Light)]. The surface of a composite block (Gradia Block) was ground with silicon carbide paper. After treatment with a silane primer, a adhesive agent was applied to each testing specimen. The specimens were then bonded with a light-curing resin composite. After 24 h, the shear bond strength values were determined and compared using a post hoc test (α=0.05, n=8/group). We also prepared control specimens without primer (No primer) and/or without adhesive agent (No adhesive). Results PZ/SB-Dual and GP/SB-Dual presented the highest bond strength, followed by GP/P-Bond, CP/SB-Dual, CP/R-Adhesive, No primer/SB-Dual, GP/R-Adhesive, CP/P-Bond, No primer/R-Adhesive, PZ/R-Adhesive, CP/SB-Self, PZ/P-Bond, PZ/SB-Self, and GP/SB-Self in descending order of bond strength. No primer/P-Bond, No primer/SB-Self, and all specimens in the SB-Light and No adhesive groups presented the lowest bond strengths. Conclusion A dual-curing adhesive agent (SB-Dual) containing a tributylborane derivative in combination with a silane primer (GP or PZ) presents a greater bond strength between the composite block and the repairing resin composite than the comparators used in the study.

  16. Chemical vapor deposition of three aminosilanes on silicon dioxide: surface characterization, stability, effects of silane concentration, and cyanine dye adsorption.

    Science.gov (United States)

    Zhang, Feng; Sautter, Ken; Larsen, Adam M; Findley, Daniel A; Davis, Robert C; Samha, Hussein; Linford, Matthew R

    2010-09-21

    Covalently bonded monolayers of two monofunctional aminosilanes (3-aminopropyldimethylethoxysilane, APDMES, and 3-aminopropyldiisopropylethoxysilane, APDIPES) and one trifunctional aminosilane (3-aminopropyltriethoxysilane, APTES) have been deposited on dehydrated silicon substrates by chemical vapor deposition (CVD) at 150 °C and low pressure (a few Torr) using reproducible equipment. Standard surface analytical techniques such as x-ray photoelectron spectroscopy (XPS), contact angle goniometry, spectroscopic ellipsometry, atomic force microscopy, and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) have been employed to characterize the resulting films. These methods indicate that essentially constant surface coverages are obtained over a wide range of gas phase concentrations of the aminosilanes. XPS data further indicate that the N1s/Si2p ratio is higher after CVD with the trifunctional silane (APTES) compared to the monofunctional ones, with a higher N1s/Si2p ratio for APDMES compared to that for APDIPES. AFM images show an average surface roughness of 0.12- 0.15 nm among all three aminosilane films. Stability tests indicate that APDIPES films retain most of their integrity at pH 10 for several hours and are more stable than APTES or APDMES layers. The films also showed good stability against storage in the laboratory. ToF-SIMS of these samples showed expected peaks, such as CN(-), as well as CNO(-), which may arise from an interaction between monolayer amine groups and silanols. Optical absorption measurements on adsorbed cyanine dye at the surface of the aminosilane films show the formation of dimer aggregates on the surface. This is further supported by ellipsometry measurements. The concentration of dye on each surface appears to be consistent with the density of the amines.

  17. Low-cost Solar Array Project. Feasibility of the Silane Process for Producing Semiconductor-grade Silicon

    Science.gov (United States)

    1979-01-01

    The feasibility of Union Carbide's silane process for commercial application was established. An integrated process design for an experimental process system development unit and a commercial facility were developed. The corresponding commercial plant economic performance was then estimated.

  18. Germanium silicon physics and materials

    CERN Document Server

    Willardson, R K; Bean, John C; Hull, Robert

    1998-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition ...

  19. Materials of construction for silicon crystal growth

    Science.gov (United States)

    Leipold, M. H.; Odonnell, T. P.; Hagan, M. A.

    1980-01-01

    The performance of materials for construction and in contact with molten silicon for crystal growth is presented. The basis for selection considers physical compatibility, such as thermal expansion and strength, as well as chemical compatibility as indicated by contamination of the silicon. A number of new high technology materials are included as well as data on those previously used. Emphasis is placed on the sources and processing of such materials in that results are frequently dependent on the way a material is prepared as well as its intrinsic constituents.

  20. Synthesis of a novel hydantoin-containing silane and its effect on the tracking and bacteria resistance of addition-cure liquid silicone rubber

    Science.gov (United States)

    Liu, Tian; Zeng, Xingrong; Fang, Weizhen; Lai, Xuejun; Li, Hongqiang

    2017-11-01

    A novel hydantoin-containing silane, [3-(5,5-dimethylhydantoinurethano) propyl] ethoxyallyloxysilane (DMHURPAS), was synthesized and the structure was characterized by FTIR and 1H NMR. The effect of DMHURPAS was investigated on the anti-tracking and antibacterial properties of addition-cure liquid silicone rubber (ALSR) after surface chlorination. It was found that ALSR containing only 1.5 phr of DMHURPAS passed 1A 4.5 kV level and erosion mass decreased from 0.843 g to 0.037 g. The thermal stability of ALSR was significantly improved and the mechanical properties were also enhanced. From thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR), ALSR/DMHURPAS showed significant decrease of carbonyl compounds and cyclic oligomers but increase of CH4 and CO2 during thermal degradation, indicating that DMHURPAS could inhibit oxidation of methyl groups and unzipping reaction, and promote the cleavage of methyl groups in ALSR. The antibacterial rates of ALSR containing 2.0 phr of DMHURPAS against Escherichia coli and Staphylococcus aureus were 95.7% and 83.4%, respectively.

  1. Interaction of nanosecond laser pulse with tetramethyl silane (Si(CH34 clusters: Generation of multiply charged silicon and carbon ions

    Directory of Open Access Journals (Sweden)

    Purav M. Badani

    2011-12-01

    Full Text Available Present work reports significantly high levels of ionization, eventually leading to Coulomb explosion of Tetramethyl silane (TMS clusters, on interaction with laser pulses of intensity ∼109 W/cm2. Tetramethyl silane clusters, prepared by supersonic expansion were photoionized at 266, 355 or 532 nm and the resultant ions were detected using time-of-flight mass spectrometer. It is observed that wavelength of irradiation and the size of the cluster are crucial parameters which drastically affect the nature of charge species generated upon photoionization of cluster. The results show that clusters absorb significantly higher energy from the laser field at longer wavelengths (532 nm and generate multiply charged silicon and carbon ions which have large kinetic energies. Further, laser-cluster interaction at different wavelengths has been quantified and charge densities at 266, 355 and 532 nm are found to be 4x 1010, 5x 1010 and 5x 1011 charges/cm3 respectively. These unusual results have been rationalized based on dominance of secondary ionization processes at 532 nm ultimately leading to Coulomb explosion of clusters. In another set of experiments, multiply charged ions of Ar (up to +5 state and Kr (up to +6 state were observed when TMS doped inert gas clusters were photoionized at 532 and 355 nm. The extent of energy absorption at these two wavelengths is clearly manifested from the charge state of the atomic ions generated upon Coulomb disintegration of the doped cluster. These experiments thus demonstrate a novel method for generation of multiply charged atomic ions of inert gases at laser intensity of ∼ 109 W/cm2. The average size of the cluster exhibiting Coulomb explosion phenomena under giga watt intensity conditions has been estimated to be ∼ 6 nm. Experimental results obtained in the present work agree qualitatively with the model proposed earlier [D. Niu, H. Li, F. Liang, L. Wen, X. Luo, B. Wang, and H. Qu, J. Chem. Phys. 122, 151103

  2. Method of high purity silane preparation

    Science.gov (United States)

    Tsuo, Y. Simon; Belov, Eugene P.; Gerlivanov, Vadim G.; Zadde, Vitali V.; Kleschevnikova, Solomonida I.; Korneev, Nikolai N.; Lebedev, Eugene N.; Pinov, Akhsarbek B.; Ryabenko, Eugene A.; Strebkov, Dmitry S.; Chernyshev, Eugene A.

    2000-01-01

    A process for the preparation of high purity silane, suitable for forming thin layer silicon structures in various semiconductor devices and high purity poly- and single crystal silicon for a variety of applications, is provided. Synthesis of high-purity silane starts with a temperature assisted reaction of metallurgical silicon with alcohol in the presence of a catalyst. Alcoxysilanes formed in the silicon-alcohol reaction are separated from other products and purified. Simultaneous reduction and oxidation of alcoxysilanes produces gaseous silane and liquid secondary products, including, active part of a catalyst, tetra-alcoxysilanes, and impurity compounds having silicon-hydrogen bonds. Silane is purified by an impurity adsorption technique. Unreacted alcohol is extracted and returned to the reaction with silicon. Concentrated mixture of alcoxysilanes undergoes simultaneous oxidation and reduction in the presence of a catalyst at the temperature -20.degree. C. to +40.degree. C. during 1 to 50 hours. Tetra-alcoxysilane extracted from liquid products of simultaneous oxidation and reduction reaction is directed to a complete hydrolysis. Complete hydrolysis of tetra-alcoxysilane results in formation of industrial silica sol and alcohol. Alcohol is dehydrated by tetra-alcoxysilane and returned to the reaction with silicon.

  3. Amorphous silicon as high index photonic material

    Science.gov (United States)

    Lipka, T.; Harke, A.; Horn, O.; Amthor, J.; Müller, J.

    2009-05-01

    Silicon-on-Insulator (SOI) photonics has become an attractive research topic within the area of integrated optics. This paper aims to fabricate SOI-structures for optical communication applications with lower costs compared to standard fabrication processes as well as to provide a higher flexibility with respect to waveguide and substrate material choice. Amorphous silicon is deposited on thermal oxidized silicon wafers with plasma-enhanced chemical vapor deposition (PECVD). The material is optimized in terms of optical light transmission and refractive index. Different a-Si:H waveguides with low propagation losses are presented. The waveguides were processed with CMOS-compatible fabrication technologies and standard DUV-lithography enabling high volume production. To overcome the large mode-field diameter mismatch between incoupling fiber and sub-μm waveguides three dimensional, amorphous silicon tapers were fabricated with a KOH etched shadow mask for patterning. Using ellipsometric and Raman spectroscopic measurements the material properties as refractive index, layer thickness, crystallinity and material composition were analyzed. Rapid thermal annealing (RTA) experiments of amorphous thin films and rib waveguides were performed aiming to tune the refractive index of the deposited a-Si:H waveguide core layer after deposition.

  4. Development of processes for the production of solar grade silicon from halides and alkali metals, phase 1 and phase 2

    Science.gov (United States)

    Dickson, C. R.; Gould, R. K.; Felder, W.

    1981-01-01

    High temperature reactions of silicon halides with alkali metals for the production of solar grade silicon are described. Product separation and collection processes were evaluated, measure heat release parameters for scaling purposes and effects of reactants and/or products on materials of reactor construction were determined, and preliminary engineering and economic analysis of a scaled up process were made. The feasibility of the basic process to make and collect silicon was demonstrated. The jet impaction/separation process was demonstrated to be a purification process. The rate at which gas phase species from silicon particle precursors, the time required for silane decomposition to produce particles, and the competing rate of growth of silicon seed particles injected into a decomposing silane environment were determined. The extent of silane decomposition as a function of residence time, temperature, and pressure was measured by infrared absorption spectroscopy. A simplistic model is presented to explain the growth of silicon in a decomposing silane enviroment.

  5. Materials issues in silicon integrated circuit processing

    International Nuclear Information System (INIS)

    Wittmer, M.; Stimmell, J.; Strathman, M.

    1986-01-01

    The symposium on ''Materials Issues in Integrated Circuit Processing'' sought to bring together all of the materials issued pertinent to modern integrated circuit processing. The inherent properties of the materials are becoming an important concern in integrated circuit manufacturing and accordingly research in materials science is vital for the successful implementation of modern integrated circuit technology. The session on Silicon Materials Science revealed the advanced stage of knowledge which topics such as point defects, intrinsic and extrinsic gettering and diffusion kinetics have achieved. Adaption of this knowledge to specific integrated circuit processing technologies is beginning to be addressed. The session on Epitaxy included invited papers on epitaxial insulators and IR detectors. Heteroepitaxy on silicon is receiving great attention and the results presented in this session suggest that 3-d integrated structures are an increasingly realistic possibility. Progress in low temperature silicon epitaxy and epitaxy of thin films with abrupt interfaces was also reported. Diffusion and Ion Implantation were well presented. Regrowth of implant-damaged layers and the nature of the defects which remain after regrowth were discussed in no less than seven papers. Substantial progress was also reported in the understanding of amorphising boron implants and the use of gallium implants for the formation of shallow p/sup +/ -layers

  6. Analysis of Gas Membrane Ultra-High Purification of Small Quantities of Mono-Isotopic Silane

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F [ORNL; Hart, Kevin J [ORNL

    2016-09-01

    A small quantity of high-value, crude, mono-isotopic silane is a prospective gas for a small-scale, high-recovery, ultra-high membrane purification process. This is an unusual application of gas membrane separation for which we provide a comprehensive analysis of a simple purification model. The goal is to develop direct analytic expressions for estimating the feasibility and efficiency of the method, and guide process design; this is only possible for binary mixtures of silane in the dilute limit which is a somewhat realistic case. Among the common impurities in crude silane, methane poses a special membrane separation challenge since it is chemically similar to silane. Other potential problematic surprises are: ethylene, diborane and ethane (in this order). Nevertheless, we demonstrate, theoretically, that a carefully designed membrane system may be able to purify mono-isotopic, crude silane to electronics-grade level in a reasonable amount of time and expenses. We advocate a combination of membrane materials that preferentially reject heavy impurities based on mobility selectivity, and light impurities based on solubility selectivity. We provide estimates for the purification of significant contaminants of interest. To improve the separation selectivity, it is advantageous to use a permeate chamber under vacuum, however this also requires greater control of in-leakage of impurities in the system. In this study, we suggest cellulose acetate and polydimethylsiloxane as examples of membrane materials on the basis of limited permeability data found in the open literature. We provide estimates on the membrane area needed and priming volume of the cell enclosure for fabrication purposes when using the suggested membrane materials. These estimates are largely theoretical in view of the absence of reliable experimental data for the permeability of silane. Last but not least, future extension of this work to the non-dilute limit may apply to the recovery of silane from

  7. Development of Doped Microcrystalline Silicon Oxide and its Application to Thin‑Film Silicon Solar Cells

    NARCIS (Netherlands)

    Lambertz, A.

    2015-01-01

    The aim of the present study is the development of doped microcrystalline silicon oxide (µc‑SiOx:H) alloys and its application in thin‑film silicon solar cells. The doped µc‑SiOx:H material was prepared from carbon dioxide (CO2), silane (SiH4), hydrogen (H2) gas mixtures using plasma enhanced

  8. Silicon based light-emitting materials and devices

    International Nuclear Information System (INIS)

    Chen Weide

    1999-01-01

    Silicon based light-emitting materials and devices are the key to optoelectronic integration. Recently, there has been significant progress in materials engineering methods. The author reviews the latest developments in this area including erbium doped silicon, porous silicon, nanocrystalline silicon and Si/SiO 2 superlattice structures. The incorporation of these different materials into devices is described and future device prospects are assessed

  9. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    Science.gov (United States)

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  10. Silicon as an anisotropic mechanical material

    DEFF Research Database (Denmark)

    Thomsen, Erik Vilain; Reck, Kasper; Skands, Gustav Erik

    2014-01-01

    While silicon is an anisotropic material it is often in literature treated as an isotropic material when it comes to plate calculations. This leads to considerable errors in the calculated deflection. To overcome this problem, we present an in-depth analysis of the bending behavior of thin crysta...... analytical models involving crystalline plates, such as those often found in the field of micro electro mechanical systems. The effect of elastic boundary conditions is taken into account by using an effective radius of the plate....

  11. Polycrystalline silicon semiconducting material by nuclear transmutation doping

    Science.gov (United States)

    Cleland, John W.; Westbrook, Russell D.; Wood, Richard F.; Young, Rosa T.

    1978-01-01

    A NTD semiconductor material comprising polycrystalline silicon having a mean grain size less than 1000 microns and containing phosphorus dispersed uniformly throughout the silicon rather than at the grain boundaries.

  12. Strained silicon as a new electro-optic material

    DEFF Research Database (Denmark)

    Jacobsen, Rune Shim; Andersen, Karin Nordström; Borel, Peter Ingo

    2006-01-01

    For decades, silicon has been the material of choice for mass fabrication of electronics. This is in contrast to photonics, where passive optical components in silicon have only recently been realized1, 2. The slow progress within silicon optoelectronics, where electronic and optical...... functionalities can be integrated into monolithic components based on the versatile silicon platform, is due to the limited active optical properties of silicon3. Recently, however, a continuous-wave Raman silicon laser was demonstrated4; if an effective modulator could also be realized in silicon, data...... processing and transmission could potentially be performed by all-silicon electronic and optical components. Here we have discovered that a significant linear electro-optic effect is induced in silicon by breaking the crystal symmetry. The symmetry is broken by depositing a straining layer on top...

  13. Solar cell structure incorporating a novel single crystal silicon material

    Science.gov (United States)

    Pankove, Jacques I.; Wu, Chung P.

    1983-01-01

    A novel hydrogen rich single crystal silicon material having a band gap energy greater than 1.1 eV can be fabricated by forming an amorphous region of graded crystallinity in a body of single crystalline silicon and thereafter contacting the region with atomic hydrogen followed by pulsed laser annealing at a sufficient power and for a sufficient duration to recrystallize the region into single crystal silicon without out-gassing the hydrogen. The new material can be used to fabricate semiconductor devices such as single crystal silicon solar cells with surface window regions having a greater band gap energy than that of single crystal silicon without hydrogen.

  14. High surface area silicon materials: fundamentals and new technology.

    Science.gov (United States)

    Buriak, Jillian M

    2006-01-15

    Crystalline silicon forms the basis of just about all computing technologies on the planet, in the form of microelectronics. An enormous amount of research infrastructure and knowledge has been developed over the past half-century to construct complex functional microelectronic structures in silicon. As a result, it is highly probable that silicon will remain central to computing and related technologies as a platform for integration of, for instance, molecular electronics, sensing elements and micro- and nanoelectromechanical systems. Porous nanocrystalline silicon is a fascinating variant of the same single crystal silicon wafers used to make computer chips. Its synthesis, a straightforward electrochemical, chemical or photochemical etch, is compatible with existing silicon-based fabrication techniques. Porous silicon literally adds an entirely new dimension to the realm of silicon-based technologies as it has a complex, three-dimensional architecture made up of silicon nanoparticles, nanowires, and channel structures. The intrinsic material is photoluminescent at room temperature in the visible region due to quantum confinement effects, and thus provides an optical element to electronic applications. Our group has been developing new organic surface reactions on porous and nanocrystalline silicon to tailor it for a myriad of applications, including molecular electronics and sensing. Integration of organic and biological molecules with porous silicon is critical to harness the properties of this material. The construction and use of complex, hierarchical molecular synthetic strategies on porous silicon will be described.

  15. Process Research on Polycrystalline Silicon Material (PROPSM)

    Science.gov (United States)

    Culik, J. S.; Wrigley, C. Y.

    1985-01-01

    Results of hydrogen-passivated polycrysalline silicon solar cell research are summarized. The short-circuit current of solar cells fabricated from large-grain cast polycrystalline silicon is nearly equivalent to that of single-crystal cells, which indicates long bulk minority-carrier diffusion length. Treatments with molecular hydrogen showed no effect on large-grain cast polycrystalline silicon solar cells.

  16. Silicon-Based Nanoscale Composite Energetic Materials

    Science.gov (United States)

    2013-02-01

    1193-1211. 9. Krishnamohan, G., E.M. Kurian, and H.R. Rao, Thermal Analysis and Inverse Burning Rate Studies on Silicon-Potassium Nitrate System...reported in a journal paper and appears in the Appendix. Multiscale Nanoporous Silicon Combustion Introduction for nanoporous silicon effort While

  17. Will silicon be the photonic material of the third millenium?

    International Nuclear Information System (INIS)

    Pavesi, L

    2003-01-01

    Silicon microphotonics, a technology which merges photonics and silicon microelectronic components, is rapidly evolving. Many different fields of application are emerging: transceiver modules for optical communication systems, optical bus systems for ULSI circuits, I/O stages for SOC, displays, .... In this review I will give a brief motivation for silicon microphotonics and try to give the state-of-the-art of this technology. The ingredient still lacking is the silicon laser: a review of the various approaches will be presented. Finally, I will try to draw some conclusions where silicon is predicted to be the material to achieve a full integration of electronic and optical devices. (topical review)

  18. Nanostructured silicon for photonics from materials to devices

    CERN Document Server

    Gaburro, Z; Daldosso, N

    2006-01-01

    The use of light to channel signals around electronic chips could solve several current problems in microelectronic evolution including: power dissipation, interconnect bottlenecks, input/output from/to optical communication channels, poor signal bandwidth, etc. It is unfortunate that silicon is not a good photonic material: it has a poor light-emission efficiency and exhibits a negligible electro-optical effect. Silicon photonics is a field having the objective of improving the physical properties of silicon; thus turning it into a photonic material and permitting the full convergence of elec

  19. Silicon radiation detectors: materials and applications

    International Nuclear Information System (INIS)

    Walton, J.T.; Haller, E.E.

    1982-10-01

    Silicon nuclear radiation detectors are available today in a large variety of sizes and types. This profusion has been made possible by the ever increasing quality and diameter silicon single crystals, new processing technologies and techniques, and innovative detector design. The salient characteristics of the four basic detector groups, diffused junction, ion implanted, surface barrier, and lithium drift are reviewed along with the silicon crystal requirements. Results of crystal imperfections detected by lithium ion compensation are presented. Processing technologies and techniques are described. Two recent novel position-sensitive detector designs are discussed - one in high-energy particle track reconstruction and the other in x-ray angiography. The unique experimental results obtained with these devices are presented

  20. Thermal decomposition of silane to form hydrogenated amorphous Si

    Science.gov (United States)

    Strongin, M.; Ghosh, A.K.; Wiesmann, H.J.; Rock, E.B.; Lutz, H.A. III

    Hydrogenated amorphous silicon is produced by thermally decomposing silane (SiH/sub 4/) or other gases comprising H and Si, at elevated temperatures of about 1700 to 2300/sup 0/C, in a vacuum of about 10/sup -8/ to 10/sup -4/ torr. A gaseous mixture is formed of atomic hydrogen and atomic silicon. The gaseous mixture is deposited onto a substrate to form hydrogenated amorphous silicon.

  1. Advanced silicon materials for photovoltaic applications

    CERN Document Server

    Pizzini, Sergio

    2012-01-01

    Today, the silicon feedstock for photovoltaic cells comes from processes which were originally developed for the microelectronic industry. It covers almost 90% of the photovoltaic market, with mass production volume at least one order of magnitude larger than those devoted to microelectronics. However, it is hard to imagine that this kind of feedstock (extremely pure but heavily penalized by its high energy cost) could remain the only source of silicon for a photovoltaic market which is in continuous expansion, and which has a cumulative growth rate in excess of 30% in the last few years. Ev

  2. Measuring Trace Hydrocarbons in Silanes

    Science.gov (United States)

    Lesser, L. A.

    1984-01-01

    Technique rapid and uses standard analytical equipment. Silane gas containing traces of hydrocarbons injected into carrier gas of moist nitrogen having about 0.2 percent water vapor. Carrier, water and silane pass through short column packed with powdered sodium hydroxide which combines moisture and silane to form nonvolatile sodium silicate. Carrier gas free of silane but containing nonreactive hydrocarbons, pass to silica-gel column where chromatographic separation takes place. Hydrocarbons measured by FID.

  3. The Effect of Silane Coupling Agents on a Composite Polyamide-6/Talc

    Directory of Open Access Journals (Sweden)

    H. Wiebeck

    1998-12-01

    Full Text Available This paper evaluates the effect of the addition of silane agents on the mechanical properties (tensile strength, hardness and flexibility of the composite polyamide-6/talc. For this purpose, 30% and 40% of a talc with and without the addition of silane agents were incorporated into polyamide-6. Three kinds of silane agents were used, resulting in nine formulations. Comparing the experimental results, it is concluded that the silane agents improve the mechanical properties of the composite material.

  4. Effect of silane coupling agents on basalt fiber-epoxidized vegetable oil matrix composite materials analyzed by the single fiber fragmentation technique

    OpenAIRE

    Samper Madrigal, María Dolores; Petrucci, R.; Sánchez Nacher, Lourdes; Balart Gimeno, Rafael Antonio; Kenny, J. M.

    2015-01-01

    The fiber-matrix interfacial shear strength (IFSS) of biobased epoxy composites reinforced with basalt fiber was investigated by the fragmentation method. Basalt fibers were modified with four different silanes, (3-aminopropyl)trimethoxysilane, [3-(2-aminoethylamino)propyl]-trimethoxysilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane and (3-glycidyloxypropyl)trimethoxysilane to improve the adhesion between the basalt fiber and the resin. The analysis of the fiber tensile strength...

  5. Silanated Surface Treatment: Effects on the Bond Strength to Lithium Disilicate Glass-Ceramic.

    Science.gov (United States)

    Baratto, Samantha Schaffer Pugsley; Spina, Denis Roberto Falcão; Gonzaga, Carla Castiglia; Cunha, Leonardo Fernandes da; Furuse, Adilson Yoshio; Baratto Filho, Flares; Correr, Gisele Maria

    2015-10-01

    The aim of this study was to evaluate the effect of silanization protocols on the bond strength of two resin cements to a lithium disilicate glass-ceramic. Thirty-two ceramic discs were assigned to 2 groups (n=16): G1 - dual-cured resin cement and G2 - light-cured resin cement. Four subgroups were evaluated according to the used silanization protocol. The glass-ceramic was etched with 10% hydrofluoric acid for 20 s and silane was applied for 1 min, as follows: CTL - according to the manufacturer's instructions; HA - dried with hot air; NWA - washed and dried with water and air at room temperature; HWA - washed and dried with hot water and hot air. Thereafter, adhesive was applied and light-cured for 20 s. Silicon molds were used to prepare resin cement cylinders (1x1 mm) on the ceramic surface. The specimens were stored in deionized water at 37 °C for 48 h and subjected to a micro-shear test. The data were submitted to statistical analysis (?#61537;=0.05). Group G1 showed higher bond strengths than G2, except for the CTL and NWA subgroups. Differences as function of the silanization protocol were only observed in G1: HWA (25.13±6.83)≥HA (22.95±7.78)≥CTL(17.44±7.24) ≥NWA(14.63±8.76). For G2 there was no difference among the subgroups. In conclusion, the silanization protocol affected the resin cement/ceramic bond strengths, depending on the material. Washing/drying with hot water and/or hot air increased only the bond strength of the dual-cured resin cement.

  6. Evaluation on electrical resistivity of silicon materials after electron ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 38; Issue 5. Evaluation on ... This research deals with the study of electron beam melting (EBM) methodology utilized in melting silicon material and subsequently discusses on the effect of oxygen level on electrical resistivity change after EBM process. The oxygen ...

  7. Development of the silane process for the production of low-cost polysilicon

    Science.gov (United States)

    Iya, S. K.

    1986-01-01

    It was recognized that the traditional hot rod type deposition process for decomposing silane is energy intensive, and a different approach for converting silane to silicon was chosen. A 1200 metric tons/year capacity commercial plant was constructed in Moses Lake, Washington. A fluidized bed processor was chosen as the most promising technology and several encouraging test runs were conducted. This technology continues to be very promising in producing low cost polysilicon. The Union Carbide silane process and the research development on the fluidized bed silane decomposition are discussed.

  8. Defects and impurities in silicon materials an introduction to atomic-level silicon engineering

    CERN Document Server

    Langouche, Guido

    2015-01-01

    This book emphasizes the importance of the fascinating atomistic insights into the defects and the impurities as well as the dynamic behaviors in silicon materials, which have become more directly accessible over the past 20 years. Such progress has been made possible by newly developed experimental methods, first principle theories, and computer simulation techniques. The book is aimed at young researchers, scientists, and technicians in related industries. The main purposes are to provide readers with 1) the basic physics behind defects in silicon materials, 2) the atomistic modeling as well as the characterization techniques related to defects and impurities in silicon materials, and 3) an overview of the wide range of the research fields involved.

  9. Plasma deposition of amorphous silicon-based materials

    CERN Document Server

    Bruno, Giovanni; Madan, Arun

    1995-01-01

    Semiconductors made from amorphous silicon have recently become important for their commercial applications in optical and electronic devices including FAX machines, solar cells, and liquid crystal displays. Plasma Deposition of Amorphous Silicon-Based Materials is a timely, comprehensive reference book written by leading authorities in the field. This volume links the fundamental growth kinetics involving complex plasma chemistry with the resulting semiconductor film properties and the subsequent effect on the performance of the electronic devices produced. Key Features * Focuses on the plasma chemistry of amorphous silicon-based materials * Links fundamental growth kinetics with the resulting semiconductor film properties and performance of electronic devices produced * Features an international group of contributors * Provides the first comprehensive coverage of the subject, from deposition technology to materials characterization to applications and implementation in state-of-the-art devices.

  10. Aqueous Processing of Si3N4 Powder with Chem-Adsorbed Silanes

    National Research Council Canada - National Science Library

    Colic, Miroslav

    1996-01-01

    .... Addition of salt to dispersed silicon nitride slurries with particles coated with polyethyleneglycol-silane, caused the collapse of the 22 atoms long chains and residual electrical double layer...

  11. Carbon Nanotube Templated Microfabrication of Porous Silicon-Carbon Materials

    Science.gov (United States)

    Song, Jun; Jensen, David; Dadson, Andrew; Vail, Michael; Linford, Matthew; Vanfleet, Richard; Davis, Robert

    2010-10-01

    Carbon nanotube templated microfabrication (CNT-M) of porous materials is demonstrated. Partial chemical infiltration of three dimensional carbon nanotube structures with silicon resulted in a mechanically robust material, precisely structured from the 10 nm scale to the 100 micron scale. Nanoscale dimensions are determined by the diameter and spacing of the resulting silicon/carbon nanotubes while the microscale dimensions are controlled by lithographic patterning of the CNT growth catalyst. We demonstrate the utility of this hierarchical structuring approach by using CNT-M to fabricate thin layer chromatography (TLC) separations media with precise microscale channels for fluid flow control and nanoscale porosity for high analyte capacity.

  12. Characterization of electrical and optical properties of silicon based materials

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Guobin

    2009-12-04

    In this work, the electrical and luminescence properties of a series of silicon based materials used for photovoltaics, microelectronics and nanoelectronics have been investigated by means of electron beam induced current (EBIC), cathodoluminescence (CL), photoluminescence (PL) and electroluminescence (EL) methods. Photovoltaic materials produced by block casting have been investigated by EBIC on wafers sliced from different parts of the ingot. Various solar cell processings have been compared in parallel wafers by means of EBIC collection efficiency measurements and contrast-temperature C(T) behaviors of the extended defects, i. e. dislocations and grain boundaries (GBs). It was found that the solar cell processing with phosphorus diffusion gettering (PDG) followed with a SiN firing greatly reduces the recombination activity of extended defects at room temperature, and improves the bulk property simultaneously. A remaining activity of the dislocations indicates the limitation of the PDG at extended defects. Abnormal behavior of the dislocation activity after certain solar cell processes was also observed in the region with high dislocation density, the dislocations are activated after certain solar cell processings. In order to evaluate the properties of a thin polycrystalline silicon layer prepared by Al-induced layer exchange (Alile) technique, epitaxially layer grown on silicon substrate with different orientations was used as a model system to investigate the impact by the process temperature and the substrates. EBIC energy dependent collection efficiency measurements reveal an improvement of the epilayer quality with increasing substrate temperature during the growth from 450 C to 650 C, and a decrease of epilayer quality at 700 C. PL measurements on the epitaxially grown Si layer on silicon substrates revealed no characteristic dislocation-related luminescence (DRL) lines at room temperature and 77 K, while in the samples prepared by Alile process, intense

  13. Chemical modeling of a high-density inductively-coupled plasma reactor containing silane

    NARCIS (Netherlands)

    Kovalgin, Alexeij Y.; Boogaard, A.; Brunets, I.; Holleman, J.; Schmitz, Jurriaan

    We carried out the modeling of chemical reactions in a silane-containing remote Inductively Coupled Plasma Enhanced Chemical Vapor Deposition (ICPECVD) system, intended for deposition of silicon, silicon oxide, and silicon nitride layers. The required electron densities and Electron Energy

  14. Porous silicon based anode material formed using metal reduction

    Science.gov (United States)

    Anguchamy, Yogesh Kumar; Masarapu, Charan; Deng, Haixia; Han, Yongbong; Venkatachalam, Subramanian; Kumar, Sujeet; Lopez, Herman A.

    2015-09-22

    A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m.sup.2/g to about 200 m.sup.2/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cm.sup.2 to about 3.5 mg/cm.sup.2. In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.

  15. Coated silicon comprising material for protection against environmental corrosion

    Science.gov (United States)

    Hazel, Brian Thomas (Inventor)

    2009-01-01

    In accordance with an embodiment of the invention, an article is disclosed. The article comprises a gas turbine engine component substrate comprising a silicon material; and an environmental barrier coating overlying the substrate, wherein the environmental barrier coating comprises cerium oxide, and the cerium oxide reduces formation of silicate glass on the substrate upon exposure to corrodant sulfates.

  16. Low cost silicon solar array project. Task 1: Establishment of the feasibility of a process capable of low cost, high volume production of silane, SiH4

    Science.gov (United States)

    Breneman, W. C.; Mui, J. Y. P.

    1976-01-01

    The kinetics of the redistribution of dichlorosilane and trichlorosilane vapor over a tertiary amine ion exchange resin catalyst were investigated. The hydrogenation of SiCl4 to form HSiCl3 and the direct synthesis of H2SiCl2 from HCl gas and metallurgical silicon metal were also studied. The purification of SiH4 using activated carbon adsorbent was studied along with a process for storing SiH4 absorbed on carbon. The latter makes possible a higher volumetric efficiency than compressed gas storage. A mini-plant designed to produce ten pounds per day of SiH4 is described.

  17. BUILDING MATERIALS AND PRODUCTS BASED ON SILICON MANGANESE SLAGS

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2016-05-01

    Full Text Available Raising of problem. Currently of particular relevance was given to the matter of introduction in manufacture of building materials and products, resource-saving techniques and technologies; integrated use of raw materials and materials that prevent or significantly reduce their harmful impact on the environment. This allows you to recycle hundreds of thousands of tons of the fiery liquid slags of silicon manganese and to develop effective structural materials that can replace metals, non-metallic building materials of natural origin, concretes, cast stone, plastics and refractories. Purpose. The study of the structure and properties of building materials and products from electric furnace slag of silicon manganese. Conclusion. Slags from the smelting of silicon manganese are classified as acidic. Their lime factor is in the range of 0.47–0.52. The composition of the slag located in the heterogeneous region SiO2 near the line of separation of cristobalite spread to the crystallization of wollastonite, according to the ternary system MnO-CaO-SiO2, which in consideration of their stability, allows the development of technology of building materials (gravel, sand, granulated slag, etc. and products (foundation blocks, road slabs, containers for transportation and storage of hazardous waste, and others.

  18. Hydrogen interactions with silicon-on-insulator materials

    OpenAIRE

    Rivera de Mena, A.J.

    2003-01-01

    The booming of microelectronics in recent decades has been made possible by the excellent properties of the Si/SiO2 interface in oxide on silicon systems.. This semiconductor/insulator combination has proven to be of great value for the semiconductor industry. It has made it possible to continuously increase the number of transistors per chip until the physical limit of integration is now almost reached. Silicon-on-insulator (SOI) materials were early on seen as a step in the logical evolutio...

  19. Process research of non-CZ silicon material

    Science.gov (United States)

    Campbell, R. B.

    1984-01-01

    Advanced processing techniques for non-CZ silicon sheet material that might improve the cost effectiveness of photovoltaic module production were investigated. Specifically, the simultaneous diffusion of liquid boron and liquid phosphorus organometallic precursors into n-type dendritic silicon web was examined. The simultaneous junction formation method for solar cells was compared with the sequential junction formation method. The electrical resistivity of the n-n and p-n junctions was discussed. Further research activities for this program along with a program documentation schedule are given.

  20. Development of silicone rubber-type neutron shielding material

    International Nuclear Information System (INIS)

    Do, Jae Bum; Cho, Soo Hang; Kim, Ik Soo; Oh, Seung Chul; Hong, Soon Seok; Noh, Sung Ki; Jeong, Duk Yeon.

    1997-06-01

    Because the exposure to radiation in the nuclear facilities can be fatal to human, it is important to reduce the radiation dose level to a tolerable level. The purpose of this study is to develop highly effective neutron shielding materials for the shipping and storage cask of radioactive materials or in the nuclear/radiation facilities. On this study, we developed silicone rubber based neutron shielding materials and their various material properties, including neutron shielding ability, fire resistance, combustion characteristics, radiation resistance, thermal and mechanical properties were evaluated experimentally. (author). 16 tabs., 17 figs., 25 refs

  1. The dose distributions of γ ray in the silicon in and near the interfaces of silicon and various materials

    International Nuclear Information System (INIS)

    Ba Weizhen; Wu Qingzhi; He Chengfa; Chen Chaoyang

    1996-01-01

    The depth dose distributions of γ ray in the silicon in and near the interfaces of silicon and various materials, such as gold, have been studied. The dose distributions have been compared with equilibrium doses in the homogeneous silicon material, and considerable dose gradient distributions were obtained. In the case of silicon adjacent to high atomic numbered material, dose enhancement effects have been observed in and near the interfaces. The dose gradient distributions were explained by photoelectron effect, Auger effect and secondary electron transport mechanism of the low energy scattering photons

  2. Silicon materials outlook study for 1980-85 calendar years

    Energy Technology Data Exchange (ETDEWEB)

    Costogue, E.; Ferber, R.; Hasbach, W.; Pellin, R.; Yaws, C.

    1979-11-01

    Photovoltaic solar cell arrays converting solar energy into electrical energy can become a cost-effective, alternative energy source provided that an adequate supply of low-priced solar cell materials and automated fabrication techniques are available. Presently, the photovoltaic industry is dependent upon polycrystalline silicon which is produced primarily for the discrete semiconductor device industry. This dependency is expected to continue until DOE-sponsored new technology developments mature. Recent industry forecasts have predicted a limited supply of polycrystalline silicon material and a shortage could occur in the early 80's. The Jet Propulsion Laboratory's Technology Development and Application Lead Center formed an ad hoc committee at JPL, SERI and consultant personnel to conduct interviews with key polycrystalline manufacturers and a large cross-section of single crystal ingot growers and wafer manufacturers. Industry consensus and conclusions reached from the analysis of the data obtained by the committee are reported. The highlight of the study is that there is a high probability of polycrystalline silicon shortage by the end of CY 1982 and a strong seller's market after CY 1981 which will foster price competition for available silicon.

  3. Study of Pellets and Lumps as Raw Materials in Silicon Production from Quartz and Silicon Carbide

    Science.gov (United States)

    Dal Martello, E.; Tranell, G.; Gaal, S.; Raaness, O. S.; Tang, K.; Arnberg, L.

    2011-10-01

    The use of high-purity carbon and quartz raw materials reduces the need for comprehensive refining steps after the silicon has been produced carbothermically in the electric reduction furnace. The current work aims at comparing the reaction mechanisms and kinetics occurring in the inner part of the reduction furnace when pellets or lumpy charge is used, as well as the effect of the raw material mix. Laboratory-scale carbothermic reduction experiments have been carried out in an induction furnace. High-purity silicon carbide and two different high-purity hydrothermal quartzes were charged as raw materials at different molar ratios. The charge was in the form of lumps (size, 2-5 mm) or as powder (size, 10-20 μm), mixed and agglomerated as pellets (size, 1-3 mm) and reacted at 2273 K (2000 °C). The thermal properties of the quartzes were measured also by heating a small piece of quartz in CO atmosphere. The investigated quartzes have different reactivity in reducing atmosphere. The carbothermal reduction experiments show differences in the reacted charge between pellets and lumps as charge material. Solid-gas reactions take place from the inside of the pellets porosity, whereas reactions in lumps occur topochemically. Silicon in pellets is produced mainly in the rim zone. Larger volumes of silicon have been found when using lumpy charge. More SiO is produced when using pellets than for lumpy SiO2 for the same molar ratio and heating conditions. The two SiC polytypes used in the carbothermal reduction experiments as carbon reductants presented different reactivity.

  4. Process research on non-CZ silicon material

    Science.gov (United States)

    1982-01-01

    High risk, high payoff research areas associated with he process for producing photovoltaic modules using non-CZ sheet material are investigated. All investigations are being performed using dendritic web silicon, but all processes are directly applicable to other ribbon forms of sheet material. The technical feasibility of forming front and back junctions in non-CZ silicon using liquid dopant techniques was determined. Numerous commercially available liquid phosphorus and boron dopant solutions are investigated. Temperature-time profiles to achieve N(+) and P(+) sheet resistivities of 60 + or - 10 and 40 + or - s10 ohms per square centimeter respectively are established. A study of the optimal method of liquid dopant application is performed. The technical feasibility of forming a liquid applied diffusion mask to replace the more costly chemical vapor deposited SiO2 diffusion mask was also determined.

  5. High mechanical Q-factor measurements on silicon bulk material

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Christian; Nawrodt, Ronny; Heinert, Daniel; Schroeter, Anja; Neubert, Ralf; Thuerk, Matthias; Vodel, Wolfgang; Seidel, Paul [Institut fuer Festkoerperphysik, Helmholtzweg 5, D-07743 Jena (Germany); Tuennermann, Andreas [Institut fuer Angewandte Physik, Albert-Einstein-Strasse 15, D-07745 Jena (Germany)

    2008-07-01

    The direct observation of gravitational waves is one of the biggest challenges in science. Current detectors are limited by different kinds of noise. One of the fundamental noise sources is thermal noise arising from the optical components. One of the most promising attempts to reduce the thermal noise contribution in future detectors will be the use of high Q-factor materials at cryogenic temperatures. Silicon seems to be the most interesting material due to its excellent optical and thermal properties. We present high Q-factor measurements on bulk samples of high purity silicon in a temperature range from 5 to 300 K. The sample dimensions vary between 76.2 mm x 12..75 mm. The Q-factor exceeds 4.10{sup 8} at 6 K. The influence of the crystal orientation, doping and the sample preparation on the Q-factor is discussed.

  6. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  7. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  8. Materials Chemistry and Performance of Silicone-Based Replicating Compounds.

    Energy Technology Data Exchange (ETDEWEB)

    Brumbach, Michael T.; Mirabal, Alex James; Kalan, Michael; Trujillo, Ana B; Hale, Kevin

    2014-11-01

    Replicating compounds are used to cast reproductions of surface features on a variety of materials. Replicas allow for quantitative measurements and recordkeeping on parts that may otherwise be difficult to measure or maintain. In this study, the chemistry and replicating capability of several replicating compounds was investigated. Additionally, the residue remaining on material surfaces upon removal of replicas was quantified. Cleaning practices were tested for several different replicating compounds. For all replicating compounds investigated, a thin silicone residue was left by the replica. For some compounds, additional inorganic species could be identified in the residue. Simple solvent cleaning could remove some residue.

  9. Silicon-organic pigment material hybrids for photovoltaic application

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, T.; Weiler, U.; Jaegermann, W. [Institute of Materials Science, Darmstadt University of Technology, Petersenstreet 23, D-64287 Darmstadt (Germany); Kelting, C.; Schlettwein, D. [Institute for Applied Physics, Justus Liebig University Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Makarov, S.; Woehrle, D. [Institute of Organic and Macromolecular Chemistry, University Bremen, Leobener Street NW II, D-28359 Bremen (Germany); Abdallah, O.; Kunst, M. [Department Solar Energy, Hahn-Meitner-Institute, D-14109 Berlin (Germany)

    2007-12-14

    Hybrid materials of silicon and organic dyes have been investigated for possible application as photovoltaic material in thin film solar cells. High conversion efficiency is expected from the combination of the advantages of organic dyes for light absorption and those of silicon for charge carrier separation and transport. Low temperature remote hot wire chemical vapor deposition (HWCVD) was developed for microcrystalline silicon ({mu}c-Si) deposition using SiH{sub 4}/H{sub 2} mixtures. As model dyes zinc phthalocyanines have been evaporated from Knudsen type sources. Layers of dye on {mu}c-Si and {mu}c-Si on dye films, and composites of simultaneously and sequentially deposited Si and dye have been prepared and characterized. Raman, absorption, and photoemission spectroscopy prove the stability of the organic molecules against the rough HWCVD-Si process. Transient microwave conductivity (TRMC) indicates good electronic quality of the {mu}c-Si matrix. Energy transfer from dye to Si is indicated indirectly by luminescence and directly by photoconductivity measurements. F{sub x}ZnPc pigments with x=0,4,8,16 have been synthesized, purified and adsorbed onto H-terminated Si(1 1 1) for electronic state line up determination by photoelectron spectroscopy. For x=4 and 8 the dye frontier orbitals line up symmetrically versus the Si energy gap offering similar energetic driving forces for electron and hole injection, which is considered optimum for bulk sensitization and indicates a direction to improve the optoelectronic coupling of the organic dyes to silicon. (author)

  10. Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

    International Nuclear Information System (INIS)

    Cisneros-Pineda, Olga G.; Herrera Kao, Wilberth; Loría-Bastarrachea, María I.; Veranes-Pantoja, Yaymarilis; Cauich-Rodríguez, Juan V.; Cervantes-Uc, José M.

    2014-01-01

    The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA. - Highlights: • Effect of MPS concentration and solvents during HA silanization was studied. • Silanization rendered HA has lower crystallinity compared to untreated HA. • Silicon concentration was higher for acetone than that obtained using methanol. • Methanol–water system containing MPS at 3 wt.% provides the better results

  11. Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

    Energy Technology Data Exchange (ETDEWEB)

    Cisneros-Pineda, Olga G.; Herrera Kao, Wilberth; Loría-Bastarrachea, María I. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Veranes-Pantoja, Yaymarilis [Centro de Biomateriales, Universidad de la Habana, Avenida Universidad, s/n, e/G y Ronda, C.P. 10600 C. de La Habana (Cuba); Cauich-Rodríguez, Juan V. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Cervantes-Uc, José M., E-mail: manceruc@cicy.mx [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico)

    2014-07-01

    The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA. - Highlights: • Effect of MPS concentration and solvents during HA silanization was studied. • Silanization rendered HA has lower crystallinity compared to untreated HA. • Silicon concentration was higher for acetone than that obtained using methanol. • Methanol–water system containing MPS at 3 wt.% provides the better results.

  12. Role of metastable atoms in argon-diluted silane Rf plasmas

    International Nuclear Information System (INIS)

    Sansonnens, L.; Howling, A.A.; Hollenstein, C.; Dorier, J.L.; Kroll, U.

    1994-01-01

    The evolution of the argon metastable density has been studied by absorption spectroscopy in power-modulated plasmas of argon and a mixture of 4% silane in argon. A small concentration of silane suppresses the argon metastable density by molecular quenching. This molecular quenching adds to the electronic collisional dissociation to increase the silane dissociation rate as compared with pure silane plasmas. Using time-resolved emission spectroscopy, the role of metastables in excitation to the argon 2P 2 state has been determined in comparison with production from the ground state. In silane plasmas, emission from SiH* is due essentially to electron impact dissociation of silane, whereas in 4% silane-in-argon plasmas, emission from SiH* seems to be due to electron impact excitation of the SiH ground state. These studies demonstrate that argon is not simply a buffer gas but has an influence on the dissociation rate in the plasma-assisted deposition of amorphous silicon using argon-diluted silane plasmas. (author) 7 figs., 30 refs

  13. Synthesis of silicon containing materials using liquid hydrosilane compositions through direct injection

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Guruvenket; Sailer, Robert A.; Hoey, Justin

    2018-03-13

    An apparatus and a non-vapor-pressure dependent method of chemical vapor deposition of Si based materials using direct injection of liquid hydrosilane(s) are presented. Liquid silane precursor solutions may also include metal, non-metal or metalloid dopants, nanomaterials and solvents. An illustrative apparatus has a precursor solution and carrier gas system, atomizer and deposit head with interior chamber and a hot plate supporting the substrate. Atomized liquid silane precursor solutions and carrier gas moves through a confined reaction zone that may be heated and the aerosol and vapor are deposited on a substrate to form a thin film. The substrate may be heated prior to deposition. The deposited film may be processed further with thermal or laser processing.

  14. Influence of Chemical Composition and Structure in Silicon Dielectric Materials on Passivation of Thin Crystalline Silicon on Glass.

    Science.gov (United States)

    Calnan, Sonya; Gabriel, Onno; Rothert, Inga; Werth, Matteo; Ring, Sven; Stannowski, Bernd; Schlatmann, Rutger

    2015-09-02

    In this study, various silicon dielectric films, namely, a-SiOx:H, a-SiNx:H, and a-SiOxNy:H, grown by plasma enhanced chemical vapor deposition (PECVD) were evaluated for use as interlayers (ILs) between crystalline silicon and glass. Chemical bonding analysis using Fourier transform infrared spectroscopy showed that high values of oxidant gases (CO2 and/or N2), added to SiH4 during PECVD, reduced the Si-H and N-H bond density in the silicon dielectrics. Various three layer stacks combining the silicon dielectric materials were designed to minimize optical losses between silicon and glass in rear side contacted heterojunction pn test cells. The PECVD grown silicon dielectrics retained their functionality despite being subjected to harsh subsequent processing such as crystallization of the silicon at 1414 °C or above. High values of short circuit current density (Jsc; without additional hydrogen passivation) required a high density of Si-H bonds and for the nitrogen containing films, additionally, a high N-H bond density. Concurrently high values of both Jsc and open circuit voltage Voc were only observed when [Si-H] was equal to or exceeded [N-H]. Generally, Voc correlated with a high density of [Si-H] bonds in the silicon dielectric; otherwise, additional hydrogen passivation using an active plasma process was required. The highest Voc ∼ 560 mV, for a silicon acceptor concentration of about 10(16) cm(-3), was observed for stacks where an a-SiOxNy:H film was adjacent to the silicon. Regardless of the cell absorber thickness, field effect passivation of the buried silicon surface by the silicon dielectric was mandatory for efficient collection of carriers generated from short wavelength light (in the vicinity of the glass-Si interface). However, additional hydrogen passivation was obligatory for an increased diffusion length of the photogenerated carriers and thus Jsc in solar cells with thicker absorbers.

  15. Characterization of thin-film silicon materials and solar cells through numerical modeling

    NARCIS (Netherlands)

    Pieters, B.E.

    2008-01-01

    At present most commercially available solar cells are made of crystalline silicon (c-Si). The disadvantages of crystalline silicon solar cells are the high material cost and energy consumption during production. A cheaper alternative can be found in thin-film silicon solar cells. The thin-film

  16. Silicon carbide composites as fusion power reactor structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Snead, L.L., E-mail: SneadLL@ORNL.gov [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Nozawa, T. [Fusion Research and Development Directorate, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195 (Japan); Ferraris, M. [Politecnico di Torino-DISMIC c. Duca degli Abruzzi, 24I-10129 Torino (Italy); Katoh, Y. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Shinavski, R. [Hypertherm HTC, 18411 Gothard St., Units A/B/C, Huntington Beach, CA 92648 (United States); Sawan, M. [University of Wisconsin, Madison 417 Engineering Research Building, 1500 Engineering Drive Madison, WI 53706-1687 (United States)

    2011-10-01

    Silicon carbide was first proposed as a low activation fusion reactor material in the mid 1970s. However, serious development of this material did not begin until the early 1990s, driven by the emergence of composite materials that provided enhanced toughness and an implied ability to use these typically brittle materials in engineering application. In the decades that followed, SiC composite system was successfully transformed from a poorly performing curiosity into a radiation stable material of sufficient maturity to be considered for near term nuclear and non-nuclear systems. In this paper the recent progress in the understanding and of basic phenomenon related to the use of SiC and SiC composite in fusion applications will be presented. This work includes both fundamental radiation effects in SiC and engineering issues such as joining and general materials properties. Additionally, this paper will briefly discuss the technological gaps remaining for the practical application of this material system in fusion power devices such as DEMO and beyond.

  17. Frequency effects in silane plasmas for PECVD

    International Nuclear Information System (INIS)

    Howling, A.A.; Dorier, J.L.; Hollenstein, C.; Finger, F.; Kroll, U.

    1991-09-01

    It is generally recognised that the excitation frequency is an important parameter in rf plasma-assisted deposition. VHF silane plasmas (50-100 MHz) have been shown to produce high quality amorphous silicon films up to 20 A/s, and therefore the aim of this work is to compare the VHF range with the 13.56 MHz industrial frequency in the same reactor. The principal diagnostics used are electrical measurements and a CCD camera for spatially-resolved plasma-induced emission with Abel inversion of the plasma image. We present a comparative study of key discharge parameters such as deposition rates, plasma uniformity, ion impact energy, power transfer efficiency and powder formation for the rf range 13-70 MHz. (author) 5 figs., 19 refs

  18. Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors

    International Nuclear Information System (INIS)

    Li, Z.; Eremin, V.; Ilyashenko, I.; Ivanov, A.; Verbitskaya, E.

    1997-12-01

    Epitaxial grown thick layers (≥ 100 micrometers) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate of radiation hardened material for detectors for high-energy physics. As grown Epi-Si layers contain high concentration (up to 2 x 10 12 cm -3 ) of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (E p = 24 GeV) with a fluence of 1.5 x 10 11 cm -2 , no additional radiation induced deep traps have been detected. A reasonable explanation is that there is a sink of primary radiation induced defects (interstitial and vacancies), possibly by as-grown defects, in epitaxial layers. The ''sinking'' process, however, becomes non-effective at high radiation fluences (10 14 cm -2 ) due to saturation of epitaxial defects by high concentration of radiation induced ones. As a result, at neutron fluence of 1 x 10 14 cm -2 the deep level spectrum corresponds to well-known spectrum of radiation induced defects in high resistivity bulk Si. The net effective concentration in the space charge region equals to 3 x 10 12 cm -3 after 3 months of room temperature storage and reveals similar annealing behavior for epitaxial as compared to bulk silicon

  19. Silicon materials task of the Low Cost Solar Array Project: Effect of impurities and processing on silicon solar cells

    Science.gov (United States)

    Hopkins, R. H.; Davis, J. R.; Rohatgi, A.; Hanes, M. H.; Rai-Choudhury, P.; Mollenkopf, H. C.

    1982-01-01

    The effects of impurities and processing on the characteristics of silicon and terrestrial silicon solar cells were defined in order to develop cost benefit relationships for the use of cheaper, less pure solar grades of silicon. The amount of concentrations of commonly encountered impurities that can be tolerated in typical p or n base solar cells was established, then a preliminary analytical model from which the cell performance could be projected depending on the kinds and amounts of contaminants in the silicon base material was developed. The impurity data base was expanded to include construction materials, and the impurity performace model was refined to account for additional effects such as base resistivity, grain boundary interactions, thermal processing, synergic behavior, and nonuniform impurity distributions. A preliminary assessment of long term (aging) behavior of impurities was also undertaken.

  20. Why silicon is and will remain the dominant photovoltaic material

    Science.gov (United States)

    Singh, Rajendra

    2009-07-01

    Rising demands of energy in emerging economies, coupled with the green house gas emissions related problems around the globe have provided a unique opportunity of exploiting the advantages offered by photovoltaic (PV) systems for green energy electricity generation. Similar to cell phones, power generated by PV systems can reach over two billion people worldwide who have no access to clean energy. Only silicon based PV devices meet the low-cost manufacturing criterion of clean energy conversion (abundance of raw material and no environmental health and safety issues). The use of larger size glass substrates and manufacturing techniques similar to the ones used by the liquid crystal display industry and the large scale manufacturing of amorphous silicon thin films based modules (~ GW per year manufacturing at a single location) can lead to installed PV system cost of $3/Wp. This will open a huge market for grid connected PV systems and related markets. With further research and development, this approach can provide $2/Wp installed PV system costs in the next few years. At this cost level, PV electricity generation is competitive with any other technology, and PV power generation can be a dominant electricity generation technology in the 21st century.

  1. Resistivity measurements on the neutron irradiated detector grade silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng

    1993-11-01

    Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

  2. Additive Manufacturing of Overhang Structures Using Moisture-Cured Silicone with Support Material

    Directory of Open Access Journals (Sweden)

    Mohan Muthusamy

    2018-04-01

    Full Text Available Additive manufacturing (AM of soft materials has a wide variety of applications, such as customized or wearable devices. Silicone is one popular material for these applications given its favorable material properties. However, AM of silicone parts with overhang structures remains challenging due to the soft nature of the material. Overhang structures are the areas where there is no underlying structure. Typically, a support material is used and built in the underlying space so that the overhang structures can be built upon it. Currently, there is no support structure that has been used for AM of silicone. The goal of this study is to develop an AM process to fabricate silicone parts with overhang structures. We first identified and confirmed poly-vinyl alcohol (PVA, a water-soluble material, as a suitable support material for silicone by evaluating the adhesion strength between silicone and PVA. Process parameters for the support material, including critical overhang angle and minimum infill density for the support material, are identified. However, overhang angle alone is not the only determining factor for support material. As silicone is a soft material, it deflects due to its own weight when the height of the overhang structure increases. A finite element model is developed to estimate the critical overhang height paired with different overhang angles to determine whether the use of support material is needed. Finally, parts with overhang structures are printed to demonstrate the capability of the developed process.

  3. Silanes for Energy Efficient Elastomers

    NARCIS (Netherlands)

    Blume, Anke; Klockmann, O.; Moser, R.; Karasewitsch, E.; Herrmann, W.; Sostmann, S.

    2015-01-01

    The most mechanical rubber goods are based on carbon black filled compounds. Rubber compounds which have to withstand dynamic-mechanical forces are investigated in detail. Different silica / silane systems were introduced. Epoxysilanes show an outstanding performance in different rubber compounds. A

  4. Optimization of Fluorescent Silicon Nano material Production Using Peroxide/ Acid/ Salt Technique

    International Nuclear Information System (INIS)

    Abuhassan, L.H.

    2009-01-01

    Silicon nano material was prepared using the peroxide/ acid/ salt technique in which an aqueous silicon-based salt solution was added to H 2 O 2 / HF etchants. In order to optimize the experimental conditions for silicon nano material production, the amount of nano material produced was studied as a function of the volume of the silicon salt solution used in the synthesis. A set of samples was prepared using: 0, 5, 10, 15, and 20 ml of an aqueous 1 mg/ L metasilicate solution. The area under the corresponding peaks in the infrared (ir) absorption spectra was used as a qualitative indicator to the amount of the nano material present. The results indicated that using 10 ml of the metasilicate solution produced the highest amount of nano material. Furthermore, the results demonstrated that the peroxide/ acid/ salt technique results in the enhancement of the production yield of silicon nano material at a reduced power demand and with a higher material to void ratio. A model in which the silicon salt forms a secondary source of silicon nano material is proposed. The auxiliary nano material is deposited into the porous network causing an increase in the amount of nano material produced and a reduction in the voids present. Thus a reduction in the resistance of the porous layer, and consequently reduction in the power required, are expected. (author)

  5. An Introduction to Silanes and Their Clinical Applications in Dentistry

    NARCIS (Netherlands)

    Matinlinna, Jukka P.; Lassila, Lippo V. J.; Özcan, Mutlu; Yli-Urpo, Antti; Pekka K. Vallittu, [No Value

    2002-01-01

    Purpose: This overview presents a description of organofunctional trialkoxysilane coupling agents (silanes), their chemistry, properties, use, and some of the main clinical experiences in dentistry. Materials and Methods: The main emphasis was on major dental journals that have been reviewed from

  6. An Introduction to Silanes and Their Clinical Applications in Dentistry

    NARCIS (Netherlands)

    Matinlinna, J.P.; Lassila, L.V.J.; Ozcan, M.; Yli-Urpo, A.; Vallittu, P.K.

    2004-01-01

    Purpose: This overview presents a description of organofunctional trialkoxysilane coupling agents (silanes), their chemistry, properties, use, and some of the main clinical experiences in dentistry. Materials and Methods: The main emphasis was on major dental journals that have been reviewed from

  7. Comparison of silicone and spin-on glass packaging materials for light-emitting diode encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Liann-Be; Pan, Ke-Wei; Yen, Chia-Yi [Department of Electronic Engineering and Green Technology Research Center, Chang Gung University, Taoyuan, Taiwan (China); Jeng, Ming-Jer, E-mail: mjjeng@mail.cgu.edu.tw [Department of Electronic Engineering and Green Technology Research Center, Chang Gung University, Taoyuan, Taiwan (China); Wu, Chun-Te; Hu, Sung-Cheng; Kuo, Yang-Kuao [Chemical Systems Research Division, Chung-Shan Institute of Science and Technology Armaments Bureau, MND, Taoyuan, Taiwan (China)

    2014-11-03

    Traditional white light light-emitting diode (LED) encapsulation is performed by mixed phosphors and silicone coating on LED die. However, this encapsulation with silicone coating incurs overheated temperatures and yellowing problem. Therefore, this work attempts to replace silicone paste by using spin-on-glass (SOG) materials. Experimental results indicate that although initial brightness of SOG-based packaging is lower than that of silicone packaging, its light attenuation is significantly lower than that of silicone for a long lighting time. After the LED power is turned on for 12 h, the brightness of LED with silicone and SOG material packaging decreases from 84 to 48 lm and 73 to 59 lm, respectively. Therefore, SOG material provides an alternative packaging solution for high power LED lighting applications. - Highlights: • Spin-on-glass (SOG) material was used to replace silicone coating for LED packaging. • Initial brightness of SOG packaging is lower than that of silicone packaging. • Over time, light attenuation in SOG is much lower than that in silicone. • Color rendering index and brightness of LED packaging was optimized by Taguchi method.

  8. Analyses and characterization of fossil carbonaceous materials for silicon production

    Energy Technology Data Exchange (ETDEWEB)

    Myrvaagnes, Viktor

    2008-01-15

    Production of high silicon alloys is carried out in submerged arc furnaces by reduction of silicon bearing oxides (typically quartz) with carbon materials. Carbonaceous materials like coal, coke, charcoal and woodchips are commonly used as reduction materials in the process. Primarily based on historical prices of charcoal compared to fossil reduction materials, the Norwegian Ferroalloy Industry has mostly been using coal and coke (char) as the source of carbon. From a process point of view, the most important role of the carbonaceous material is to react with SiO gas to produce SiC. The ability of the reduction materials to react with SiO gas can be measured and the value is recognized as the reactivity of the carbon source. Reactivity is one of the most important parameters in the smelting process and is commonly acknowledged to strongly affect both productivity and specific energy consumption. The main objectives of this work has been to establish methods to characterize the material properties of fossil carbonaceous reduction materials used in the silicon process and to evaluated how these properties affect the reactivity towards SiO gas. In order to accomplish these objectives, three run of mine (ROM) single seam coals which are particularly well suited for ferroalloy production were selected. Two Carboniferous coals from USA (Blue Gem) and Poland (Staszic) with similar rank, but significantly different composition as well as a Permian coal from Australia (Peak Downs) have been characterized by chemical- and petrographical methods. Blue Gem is a homogeneous coal, low in mineral inclusions and macerals of the inertinite group and determined to have a random vitrinite reflectance of 0.71 %. Staszic has a similar reflectance of vitrinite (0.72 %), but is determined to be a very inhomogeneous coal with both inertinite macerals and minerals embedded in the vitrinite matrix. Peak Downs has a random reflectance of vitrinite of 1.32 % and is hence the coal sample of

  9. Development of Short Range Repulsive Inter-Particle Forces in Aqueous Si3N4 Slurries with Chem-Adsorbed Silanes

    National Research Council Canada - National Science Library

    Colic, Miroslav

    1997-01-01

    .... Addition of salt to dispersed silicon nitride slurries with particles coated with polyethyleneglycol-silane, caused the collapse of the 22 atoms long chains and residual electrical double layer...

  10. Research and Application Progress of Silicone Rubber Materials in Aviation

    Directory of Open Access Journals (Sweden)

    HUANG Yanhua

    2016-06-01

    Full Text Available The research progress of heat resistance, cold resistance, electrical conductivity and damping properties of aviation silicone rubber were reviewed in this article. The heat resistance properties of silicone rubber can be enhanced by changing the molecular structure (main chain, end-group, side chain and molecular weight of the gum and adding special heat-resistance filler. The cold resistance of aviation silicone rubber can be enhanced by adjusting the side chain molecular structure of the gum and the content of different gum chain. The electrical conductivity of silicone rubber can be improved by optimizing, blending and dispersing of conductive particles. The damping property of silicone rubber can be improved by designing and synthesizing of high-molecular polysiloxane damping agent. Furthermore, the application of aviation silicone rubber used in high-low temperature seal, electrical conduction and vibration damping technology are also summarized, and the high performance (for example long-term high temperature resistance, ultralow temperature resistance, high electromagnetic shelding, long-term fatigue resistance vibration damping, quasi constant modulus and so on of special silicone rubber is the future direction of aviation silicone rubber.

  11. Key factors influencing the stability of silane solution during long-term surface treatment on carbon steel

    International Nuclear Information System (INIS)

    Xian, Xiaochao; Chen, Minglu; Li, Lixin; Lin, Zhen; Xiang, Jun; Zhao, Shuo

    2013-01-01

    Highlights: •The corrosion-resistance time of silane films decreases with increasing cycle numbers. •The morphology of silane films prepared from aged solution is inhomogeneous. •Introduction of contamination ions is one reason for the poor property of aged solution. •Consumption of silane is the other reason for the poor property of aged solution. •Fe 3+ accumulated is the key factor influencing the property of silane solution. -- Abstract: The mixtures of bis-[trimethoxysilylpropyl]amine and vinyltriacetoxysilane were used for surface treatment of carbon steel, aiming to investigate the factors influencing the stability of silane solution during long-term experiment from two aspects. One is the concentrations of contamination ions, and the other is mass of silane consumed per cycle which is calculated according to concentration of Si measured by silicon molybdenum blue photometry. The results indicate that the accumulation of contamination ions, especially Fe 3+ , is the main factor leading to the condensation between the Si–OH groups in silane solution, which is responsible for the downward stability of silane solution

  12. Silicon carbide and its use as a radiation detector material

    International Nuclear Information System (INIS)

    Nava, F; Bertuccio, G; Cavallini, A; Vittone, E

    2008-01-01

    We present a comprehensive review of the properties of the epitaxial 4H silicon carbide polytype (4H–SiC). Particular emphasis is placed on those aspects of this material related to room, high-temperature and harsh environment ionizing radiation detector operation. A review of the characterization methods and electrical contacting issues and how these are related to detector performance is presented. The most recent data on charge transport parameters across the Schottky barrier and how these are related to radiation spectrometer performance are presented. Experimental results on pixel detectors having equivalent noise energies of 144 eV FWHM (7.8 electrons rms) and 196 eV FWHM at +27 °C and +100 °C, respectively, are reported. Results of studying the radiation resistance of 4H–SiC are analysed. The data on the ionization energies, capture cross section, deep-level centre concentrations and their plausible structures formed in SiC as a result of irradiation with various particles are reviewed. The emphasis is placed on the study of the 1 MeV neutron irradiation, since these thermal particles seem to play the main role in the detector degradation. An accurate electrical characterization of the induced deep-level centres by means of PICTS technique has allowed one to identify which play the main role in the detector degradation. (topical review)

  13. A study on the development of silicon carbide materials for nuclear application

    International Nuclear Information System (INIS)

    Won, Dong Yeon; Kim, Chan Jung; Lee, Jae Choon; Kim, Joon Hyung; Lim, Kyung Soo; Kim, Ki Baik

    1987-12-01

    Silicon carbide was synthesized by reaction sintering process from carbon and silicon powders as starting materials. The effects of two processing parameters, i.e., heat treatment time and temperature, were examined (to characterize the reaction sintering process) in terms of the degree of reaction and phase developed during heat treatment. The final products after reaction of silicon and carbon powders were identified as β-SiC having ZnS crystal structure. Sintering of cordierite ceramics which was used as an high temperature inorganic binder to fabricate ceramically bound silicon carbide, and phase identification of the sintered ceramics by X-ray powder diffraction techniques. (Author)

  14. Material Properties of Laser-Welded Thin Silicon Foils

    Directory of Open Access Journals (Sweden)

    M. T. Hessmann

    2013-01-01

    Full Text Available An extended monocrystalline silicon base foil offers a great opportunity to combine low-cost production with high efficiency silicon solar cells on a large scale. By overcoming the area restriction of ingot-based monocrystalline silicon wafer production, costs could be decreased to thin film solar cell range. The extended monocrystalline silicon base foil consists of several individual thin silicon wafers which are welded together. A comparison of three different approaches to weld 50 μm thin silicon foils is investigated here: (1 laser spot welding with low constant feed speed, (2 laser line welding, and (3 keyhole welding. Cross-sections are prepared and analyzed by electron backscatter diffraction (EBSD to reveal changes in the crystal structure at the welding side after laser irradiation. The treatment leads to the appearance of new grains and boundaries. The induced internal stress, using the three different laser welding processes, was investigated by micro-Raman analysis. We conclude that the keyhole welding process is the most favorable to produce thin silicon foils.

  15. Modification of the ferrite load Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} by silane agent for improving the interface in the absorbing composite; Modificacao da carga de ferrita Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} por agente silano para melhoria da interface no composito absorvedor

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, P.C.F.; Santos, P.T.A.; Silva, T.R.G.; Costa, A.C.F.M.; Araujo, E.M., E-mail: patricia.fernandes24@hotmail.com.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia de Materiais

    2014-07-01

    The main challenge of composite materials processing technology is the obtaining of an adequate interface between the components of a composite. Thus, this work aims to promote the modification of the ferrite load surface Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 3} (inorganic), by the silane agent (3-aminopropyltriethoxysilane) for introduction into the matrix of silicone (organic) rubber, and thus obtaining a efficient composite for use in electromagnetic radiation absorbing materials.

  16. Silicon Nanocrystal Synthesis in Microplasma Reactor

    Science.gov (United States)

    Nozaki, Tomohiro; Sasaki, Kenji; Ogino, Tomohisa; Asahi, Daisuke; Okazaki, Ken

    Nanocrystalline silicon particles with grains smaller than 5 nm are widely recognized as a key material in optoelectronic devices, lithium battery electrodes, and bio-medical labels. Another important characteristic is that silicon is an environmentally safe material that is used in numerous silicon technologies. To date, several synthesis methods such as sputtering, laser ablation, and plasma-enhanced chemical vapor deposition (PECVD) based on low-pressure silane chemistry (SiH4) have been developed for precise control of size and density distributions of silicon nanocrystals. In this study, we explore the possibility of microplasma technologies for efficient production of mono-dispersed nanocrystalline silicon particles on a micrometer-scale, continuous-flow plasma reactor operated at atmospheric pressure. Mixtures of argon, hydrogen, and silicon tetrachloride were activated using a very-high-frequency (144 MHz) power source in a capillary glass tube with volume of less than 1 μl. Fundamental plasma parameters of the microplasma were characterized using optical emission spectroscopy, which respectively indicated electron density of 1015 cm-3, argon excitation temperature of 5000 K, and rotational temperature of 1500 K. Such high-density non-thermal reactive plasma can decompose silicon tetrachloride into atomic silicon to produce supersaturated silicon vapor, followed by gas-phase nucleation via three-body collision: particle synthesis in high-density plasma media is beneficial for promoting nucleation processes. In addition, further growth of silicon nuclei can be terminated in a short-residence-time reactor. Micro-Raman scattering spectra showed that as-deposited particles are mostly amorphous silicon with a small fraction of silicon nanocrystals. Transmission electron micrography confirmed individual 3-15 nm silicon nanocrystals. Although particles were not mono-dispersed, they were well separated and not coagulated.

  17. Synthesis of Silicon Nanocrystals in Microplasma Reactor

    Science.gov (United States)

    Nozaki, Tomohiro; Sasaki, Kenji; Ogino, Tomohisa; Asahi, Daisuke; Okazaki, Ken

    Nanocrystalline silicon particles with a grain size of at least less than 10 nm are widely recognized as one of the key materials in optoelectronic devices, electrodes of lithium battery, bio-medical labels. There is also important character that silicon is safe material to the environment and easily gets involved in existing silicon technologies. To date, several synthesis methods such as sputtering, laser ablation, and plasma enhanced chemical vapor deposition (PECVD) based on low-pressure silane chemistry (SiH4) have been developed for precise control of size and density distributions of silicon nanocrystals. We explore the possibility of microplasma technologies for the efficient production of mono-dispersed nanocrystalline silicon particles in a micrometer-scale, continuous-flow plasma reactor operated at atmospheric pressure. Mixtures of argon, hydrogen, and silicon tetrachloride were activated using very high frequency (VHF = 144 MHz) power source in a capillary glass tube with a volume of less than 1 μ-liter. Fundamental plasma parameters of VHF capacitively coupled microplasma were characterized by optical emission spectroscopy, showing electron density of approximately 1015 cm-3 and rotational temperature of 1500 K, respectively. Such high-density non-thermal reactive plasma has a capability of decomposing silicon tetrachloride into atomic silicon to produce supersaturated atomic silicon vapor, followed by gas phase nucleation via three-body collision. The particle synthesis in high-density plasma media is beneficial for promoting nucleation process. In addition, further growth of silicon nuclei was able to be favorably terminated in a short-residence time reactor. Micro Raman scattering spectrum showed that as-deposited particles were mostly amorphous silicon with small fraction of silicon nanocrystals. Transmission electron micrograph confirmed individual silicon nanocrystals of 3-15 nm size. Although those particles were not mono-dispersed, they were

  18. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    2013-01-01

    having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...... of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer....

  19. Surface Coating of Gypsum-Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: The Surface Topography.

    Science.gov (United States)

    Khalaf, Salah; Ariffin, Zaihan; Husein, Adam; Reza, Fazal

    2015-07-01

    This study aimed to compare the surface roughness of maxillofacial silicone elastomers fabricated in noncoated and coated gypsum materials. This study was also conducted to characterize the silicone elastomer specimens after surfaces were modified. A gypsum mold was coated with clear acrylic spray. The coated mold was then used to produce modified silicone experimental specimens (n = 35). The surface roughness of the modified silicone elastomers was compared with that of the control specimens, which were prepared by conventional flasking methods (n = 35). An atomic force microscope (AFM) was used for surface roughness measurement of silicone elastomer (unmodified and modified), and a scanning electron microscope (SEM) was used to evaluate the topographic conditions of coated and noncoated gypsum and silicone elastomer specimens (unmodified and modified) groups. After the gypsum molds were characterized, the fabricated silicone elastomers molded on noncoated and coated gypsum materials were evaluated further. Energy-dispersive X-ray spectroscopy (EDX) analysis of gypsum materials (noncoated and coated) and silicone elastomer specimens (unmodified and modified) was performed to evaluate the elemental changes after coating was conducted. Independent t test was used to analyze the differences in the surface roughness of unmodified and modified silicone at a significance level of p SEM analysis results showed evident differences in surface smoothness. EDX data further revealed the presence of the desired chemical components on the surface layer of unmodified and modified silicone elastomers. Silicone elastomers with lower surface roughness of maxillofacial prostheses can be obtained simply by coating a gypsum mold. © 2014 by the American College of Prosthodontists.

  20. The chemo-mechanical effect of cutting fluid on material removal in diamond scribing of silicon

    Science.gov (United States)

    Kumar, Arkadeep; Melkote, Shreyes N.

    2017-07-01

    The mechanical integrity of silicon wafers cut by diamond wire sawing depends on the damage (e.g., micro-cracks) caused by the cutting process. The damage type and extent depends on the material removal mode, i.e., ductile or brittle. This paper investigates the effect of cutting fluid on the mode of material removal in diamond scribing of single crystal silicon, which simulates the material removal process in diamond wire sawing of silicon wafers. We conducted scribing experiments with a diamond tipped indenter in the absence (dry) and in the presence of a water-based cutting fluid. We found that the cutting mode is more ductile when scribing in the presence of cutting fluid compared to dry scribing. We explain the experimental observations by the chemo-mechanical effect of the cutting fluid on silicon, which lowers its hardness and promotes ductile mode material removal.

  1. INFLUENCE OF SILANE HEAT TREATMENT ON THE TENSILE BOND STRENGTH BETWEEN EX-3 SYNTHETIC VENEERING PORCELAIN AND COMPOSITE RESIN USING FIVE DIFFERENT ACTIVATION TEMPERATURES

    Directory of Open Access Journals (Sweden)

    Spartak Yanakiev

    2017-02-01

    Full Text Available Purpose: The purpose of the present study is to assess the effect of five different silane activation temperatures and eight activation methods on the tensile bond strength between one veneering porcelain and one composite resin material. Material and methods: A total of 81 ceramic rods were made of EX-3 veneering ceramic (Kuraray Noritake Dental, Japan. Sintered ceramic bars were grinded with diamond disks to size 10x2x2mm ± 0,05mm. The front part of each bar was polished. After ultrasonic cleaning in distilled water, the specimens were divided into nine groups. Silane was activated with air at room temperature, 38º С, 50º С, 100º С, 120º С using a custom made blow drier. In a silicone mold, a composite resin Z250 (3М ESPE, St. Paul, USA was condensed toward the bond ceramic surface. A total of 81 specimens approximately 2,0 cm long were prepared for tensile bond testing. One way ANOVA, followed by Bonferroni and Games-Howell tests were used for statistical analysis. Results: The lowest tensile bond strength was observed in the control group (3,51MPa. Group 2 yielded the highest bond strength among all groups (19,54MPa. Silane heat treatment enhanced the bond strength for all treatment methods. Within the polished specimens, the highest bond strength was yielded with warm air at 120ºС (11,31MPa. Conclusion: The most effective method for bonding Z250 composite resin to EX-3 veneering ceramic includes HF etching, silane, and adhesive resin. The most effective heat treatment method for bonding is hot air at 120ºС.

  2. Enhanced diode characteristics of organic solar cell with silanized fluorine doped tin oxide electrode

    Science.gov (United States)

    Sachdeva, Sheenam; Sharma, Sameeksha; Singh, Devinder; Tripathi, S. K.

    2018-05-01

    To investigate the diode characteristics of organic solar cell based on the planar heterojunction of 4,4'- cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC) and fullerene (C70), we report the use of silanized fluorine-doped tin oxide (FTO) anode with N1-(3-trimethoxysilylpropyl)diethyltriamine (DETA) forming monolayer. The use of silanized FTO results in the decrease of saturation current density and diode ideality factor of the device. Such silanized FTO anode is found to enhance the material quality and improve the device properties.

  3. Material and Energy Flows Associated with Select Metals in GREET 2. Molybdenum, Platinum, Zinc, Nickel, Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Benavides, Pahola T. [Argonne National Lab. (ANL), Argonne, IL (United States); Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States); Sullivan, John L. [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, Jarod C. [Argonne National Lab. (ANL), Argonne, IL (United States); Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    In this work, we analyzed the material and energy consumption from mining to production of molybdenum, platinum, zinc, and nickel. We also analyzed the production of solar- and semiconductor-grade silicon. We described new additions to and expansions of the data in GREET 2. In some cases, we used operating permits and sustainability reports to estimate the material and energy flows for molybdenum, platinum, and nickel, while for zinc and silicon we relied on information provided in the literature.

  4. Review of New Technology for Preparing Crystalline Silicon Solar Cell Materials by Metallurgical Method

    Science.gov (United States)

    Li, Man; Dai, Yongnian; Ma, Wenhui; Yang, Bin; Chu, Qingmei

    2017-11-01

    The goals of greatly reducing the photovoltaic power cost and making it less than that of thermal power to realize photovoltaic power grid parity without state subsidies are focused on in this paper. The research status, key technologies and development of the new technology for preparing crystalline silicon solar cell materials by metallurgical method at home and abroad are reviewed. The important effects of impurities and defects in crystalline silicon on its properties are analysed. The importance of new technology on reducing production costs and improving its quality to increase the cell conversion efficiency are emphasized. The previous research results show that the raw materials of crystalline silicon are extremely abundant. The product of crystalline silicon can meet the quality requirements of solar cell materials: Si ≥ 6 N, P 1 Ω cm, minority carrier life > 25 μs cell conversion efficiency of about 19.3%, the product costs energy consumption energy consumption, low carbon and sustainable development are prospected.

  5. Influence of silane films in the zinc coating post-treatment

    International Nuclear Information System (INIS)

    Costa, Marlla Vallerius da; Menezes, Tiago Lemos; Malfatti, Celia de Fraga; Muller, Iduvirges Lourdes; Oliveira, Claudia Trindade; Bonino, Jean-Pierre

    2009-01-01

    The sol-gel process based on silanes precursors appeared in recent years as a strong alternative for post-treatment to provide an optimization of the protective efficacy of zinc. Moreover, this process has been used to replace chemical chromating conversion based on hexavalent chromium. The silane films are hybrid compounds that provide characteristics of both polymeric materials, such as flexibility and functional compatibility, and ceramic materials, such as high strength and durability. The present work aimed to evaluate the influence of silane films obtained by dip-coating, on the characteristics of electrodeposited zinc coatings. The xerogel films showed a homogeneous surface and a better performance on the corrosion resistance than zinc coating without post-treatment, what can be confirmed by the electrochemical impedance results. These tests showed that application of the silane film promotes the occurrence of one more time constant compared to pure zinc system, hindering the corrosion process. (author)

  6. Silicon integrated circuits advances in materials and device research

    CERN Document Server

    Kahng, Dawon

    1981-01-01

    Silicon Integrated Circuits, Part B covers the special considerations needed to achieve high-power Si-integrated circuits. The book presents articles about the most important operations needed for the high-power circuitry, namely impurity diffusion and oxidation; crystal defects under thermal equilibrium in silicon and the development of high-power device physics; and associated technology. The text also describes the ever-evolving processing technology and the most promising approaches, along with the understanding of processing-related areas of physics and chemistry. Physicists, chemists, an

  7. Soft silicone based interpenetrating networks as materials for actuators

    DEFF Research Database (Denmark)

    Yu, Liyun; Gonzalez, Lidia; Hvilsted, Søren

    2014-01-01

    A new approach based on silicone interpenetrating networks with orthogonal chemistries has been investigated with focus on developing soft and flexible elastomers with high energy densities and small viscous losses. The interpenetrating networks are made as simple two pot mixtures...... as for the commercial available silylation based elastomers such as Elastosil RT625. The resulting interpenetrating networks are formulated to be softer than RT625 to increase the actuation caused when applying a voltage due to their softness combined with the significantly higher permittivity than the pure silicone...

  8. Formation of apatite on hydrogenated amorphous silicon (a-Si:H) film deposited by plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Liu Xuanyong; Chu, Paul K.; Ding Chuanxian

    2007-01-01

    Hydrogenated amorphous silicon films were fabricated on p-type, 100 mm diameter silicon wafers by plasma-enhanced chemical vapor deposition (PECVD) using silane and hydrogen. The structure and composition of the hydrogenated amorphous silicon films were investigated using micro-Raman spectroscopy and cross-sectional transmission electron microscopy (XTEM). The hydrogenated amorphous silicon films were subsequently soaked in simulated body fluids to evaluate apatite formation. Carbonate-containing hydroxyapatite (bone-like apatite) was formed on the surface suggesting good bone conductivity. The amorphous structure and presence of surface Si-H bonds are believed to induce apatite formation on the surface of the hydrogenated amorphous silicon film. A good understanding of the surface bioactivity of silicon-based materials and means to produce a bioactive surface is important to the development of silicon-based biosensors and micro-devices that are implanted inside humans

  9. Formation of apatite on hydrogenated amorphous silicon (a-Si:H) film deposited by plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xuanyong [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China) and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: xyliu@mail.sic.ac.cn; Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: paul.chu@cityu.edu.hk; Ding Chuanxian [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

    2007-01-15

    Hydrogenated amorphous silicon films were fabricated on p-type, 100 mm diameter <1 0 0> silicon wafers by plasma-enhanced chemical vapor deposition (PECVD) using silane and hydrogen. The structure and composition of the hydrogenated amorphous silicon films were investigated using micro-Raman spectroscopy and cross-sectional transmission electron microscopy (XTEM). The hydrogenated amorphous silicon films were subsequently soaked in simulated body fluids to evaluate apatite formation. Carbonate-containing hydroxyapatite (bone-like apatite) was formed on the surface suggesting good bone conductivity. The amorphous structure and presence of surface Si-H bonds are believed to induce apatite formation on the surface of the hydrogenated amorphous silicon film. A good understanding of the surface bioactivity of silicon-based materials and means to produce a bioactive surface is important to the development of silicon-based biosensors and micro-devices that are implanted inside humans.

  10. Material properties that predict preservative uptake for silicone hydrogel contact lenses.

    Science.gov (United States)

    Green, J Angelo; Phillips, K Scott; Hitchins, Victoria M; Lucas, Anne D; Shoff, Megan E; Hutter, Joseph C; Rorer, Eva M; Eydelman, Malvina B

    2012-11-01

    To assess material properties that affect preservative uptake by silicone hydrogel lenses. We evaluated the water content (using differential scanning calorimetry), effective pore size (using probe penetration), and preservative uptake (using high-performance liquid chromatography with spectrophotometric detection) of silicone and conventional hydrogel soft contact lenses. Lenses grouped similarly based on freezable water content as they did based on total water content. Evaluation of the effective pore size highlighted potential differences between the surface-treated and non-surface-treated materials. The water content of the lens materials and ionic charge are associated with the degree of preservative uptake. The current grouping system for testing contact lens-solution interactions separates all silicone hydrogels from conventional hydrogel contact lenses. However, not all silicone hydrogel lenses interact similarly with the same contact lens solution. Based upon the results of our research, we propose that the same material characteristics used to group conventional hydrogel lenses, water content and ionic charge, can also be used to predict uptake of hydrophilic preservatives for silicone hydrogel lenses. In addition, the hydrophobicity of silicone hydrogel contact lenses, although not investigated here, is a unique contact lens material property that should be evaluated for the uptake of relatively hydrophobic preservatives and tear components.

  11. Mathematical model of silicon smelting process basing on pelletized charge from technogenic raw materials

    Science.gov (United States)

    Nemchinova, N. V.; Tyutrin, A. A.; Salov, V. M.

    2018-03-01

    The silicon production process in the electric arc reduction furnaces (EAF) is studied using pelletized charge as an additive to the standard on the basis of the generated mathematical model. The results obtained due to the model will contribute to the analysis of the charge components behavior during melting with the achievement of optimum final parameters of the silicon production process. The authors proposed using technogenic waste as a raw material for the silicon production in a pelletized form using liquid glass and aluminum production dust from the electrostatic precipitators as a binder. The method of mathematical modeling with the help of the ‘Selector’ software package was used as a basis for the theoretical study. A model was simulated with the imitation of four furnace temperature zones and a crystalline silicon phase (25 °C). The main advantage of the created model is the ability to analyze the behavior of all burden materials (including pelletized charge) in the carbothermic process. The behavior analysis is based on the thermodynamic probability data of the burden materials interactions in the carbothermic process. The model accounts for 17 elements entering the furnace with raw materials, electrodes and air. The silicon melt, obtained by the modeling, contained 91.73 % wt. of the target product. The simulation results showed that in the use of the proposed combined charge, the recovery of silicon reached 69.248 %, which is in good agreement with practical data. The results of the crystalline silicon chemical composition modeling are compared with the real silicon samples of chemical analysis data, which showed the results of convergence. The efficiency of the mathematical modeling methods in the studying of the carbothermal silicon obtaining process with complex interphase transformations and the formation of numerous intermediate compounds using a pelletized charge as an additive to the traditional one is shown.

  12. Application of neutron transmutation doping method to initially p-type silicon material.

    Science.gov (United States)

    Kim, Myong-Seop; Kang, Ki-Doo; Park, Sang-Jun

    2009-01-01

    The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x10(19)nOmegacm(-1). The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual (32)P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was established.

  13. Microstructural Characterization of Reaction-Formed Silicon Carbide Ceramics. Materials Characterization

    Science.gov (United States)

    Singh, M.; Leonhardt, T. A.

    1995-01-01

    Microstructural characterization of two reaction-formed silicon carbide ceramics has been carried out by interference layering, plasma etching, and microscopy. These specimens contained free silicon and niobium disilicide as minor phases with silicon carbide as the major phase. In conventionally prepared samples, the niobium disilicide cannot be distinguished from silicon in optical micrographs. After interference layering, all phases are clearly distinguishable. Back scattered electron (BSE) imaging and energy dispersive spectrometry (EDS) confirmed the results obtained by interference layering. Plasma etching with CF4 plus 4% O2 selectively attacks silicon in these specimens. It is demonstrated that interference layering and plasma etching are very useful techniques in the phase identification and microstructural characterization of multiphase ceramic materials.

  14. Hydrogen interactions with silicon-on-insulator materials

    NARCIS (Netherlands)

    Rivera de Mena, A.J.

    2003-01-01

    The booming of microelectronics in recent decades has been made possible by the excellent properties of the Si/SiO2 interface in oxide on silicon systems.. This semiconductor/insulator combination has proven to be of great value for the semiconductor industry. It has made it possible to continuously

  15. Plasmonic silicon solar cells : Impact of material quality and geometry

    NARCIS (Netherlands)

    Pahud, C.; Isabella, O.; Naqavi, A.; Haug, F.J.; Zeman, M.; Herzig, H.P.; Ballif, C.

    2013-01-01

    We study n-i-p amorphous silicon solar cells with light-scattering nanoparticles in the back reflector. In one configuration, the particles are fully embedded in the zinc oxide buffer layer; In a second configuration, the particles are placed between the buffer layer and the flat back electrode. We

  16. Thermal stability of thiol and silane monolayers: A comparative study

    International Nuclear Information System (INIS)

    Chandekar, Amol; Sengupta, Sandip K.; Whitten, James E.

    2010-01-01

    The stability of self-assembled monolayers (SAMs) at elevated temperatures is of considerable technological importance. The thermal stability of 1-octadecanethiol (ODT), 16-mercaptohexadecanoic acid (MHDA) and 1H,1H,2H,2H-perfluorodecanethiol (PFDT) SAMs on gold surfaces, and of 4-aminobutyltriethoxysilane (ABTES) and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDS) assembled on hydroxylated silicon surfaces, was studied by X-ray photoelectron spectroscopy (XPS). The samples were heated in ultrahigh vacuum to temperatures in excess of that required for SAM degradation. ODT monolayers were stable to ca. 110 deg. C, while MHDA and PFDT SAMs were stable to ca. 145 deg. C. ABTES SAMs were found to be indefinitely stable to 250 deg. C, while PFDS SAMs were stable to 350 deg. C. These studies demonstrate the advantages of using silane monolayers for moderate to high temperature applications and illustrate differences that arise due to the nature of the tail group. To demonstrate the feasibility of silanes for template-directed patterning, a hydroxylated silicon oxide surface containing microcontact-printed PFDS patterns was spin-coated with a mainly hydrophilic block copolymer. Annealing the surface at 90 deg. C for 2 h caused the block copolymer to dewet the hydrophobic PFDS-patterned regions and adsorb exclusively on the unpatterned regions of the surface.

  17. SiC-Based Composite Materials Obtained by Siliconizing Carbon Matrices

    Science.gov (United States)

    Shikunov, S. L.; Kurlov, V. N.

    2017-12-01

    We have developed a method for fabrication of parts of complicated configuration from composite materials based on SiC ceramics, which employs the interaction of silicon melt with the carbon matrix having a certain composition and porosity. For elevating the operating temperatures of ceramic components, we have developed a method for depositing protective silicon-carbide coatings that is based on the interaction of the silicon melt and vapor with carbon obtained during thermal splitting of hydrocarbon molecules. The new structural ceramics are characterized by higher operating temperatures; chemical stability; mechanical strength; thermal shock, wear and radiation resistance; and parameters stability.

  18. Progress in Studies on Carbon and Silicon Carbide Nanocomposite Materials

    International Nuclear Information System (INIS)

    Xiao, P.; Chen, J.; Xian-feng, X.

    2010-01-01

    Silicon carbide nanofiber and carbon nanotubes are introduced. The structure and application of nanotubers (nanofibers) in carbon/carbon composites are emphatically presented. Due to the unique structure of nanotubers (nanofibers), they can modify the microstructure of pyrocarbon and induce the deposition of pyrocarbon with high text in carbon/carbon composites. So the carbon/carbon composites modified by CNT/CNF have more excellent properties.

  19. Formation of Mach angle profiles during wet etching of silica and silicon nitride materials

    Energy Technology Data Exchange (ETDEWEB)

    Ghulinyan, M., E-mail: ghulinyan@fbk.eu [Centre for Materials and Microsystems, Fondazione Bruno Kessler, I-38123 Povo (Italy); Bernard, M.; Bartali, R. [Centre for Materials and Microsystems, Fondazione Bruno Kessler, I-38123 Povo (Italy); Deptartment of Physics, University of Trento, I-38123 Povo (Italy); Pucker, G. [Centre for Materials and Microsystems, Fondazione Bruno Kessler, I-38123 Povo (Italy)

    2015-12-30

    Highlights: • Photoresist adhesion induces the formation of complex etch profiles in dielectrics. • Hydrofluoric acid etching of silica glass and silicon nitride materials was studied. • The phenomenon has been modeled in analogy with sonic boom propagation. • The material etch rate and resist adhesion/erosion define the final profile. - Abstract: In integrated circuit technology peeling of masking photoresist films is a major drawback during the long-timed wet etching of materials. It causes an undesired film underetching, which is often accompanied by a formation of complex etch profiles. Here we report on a detailed study of wedge-shaped profile formation in a series of silicon oxide, silicon oxynitride and silicon nitride materials during wet etching in a buffered hydrofluoric acid (BHF) solution. The shape of etched profiles reflects the time-dependent adhesion properties of the photoresist to a particular material and can be perfectly circular, purely linear or a combination of both, separated by a knee feature. Starting from a formal analogy between the sonic boom propagation and the wet underetching process, we model the wedge formation mechanism analytically. This model predicts the final form of the profile as a function of time and fits the experimental data perfectly. We discuss how this knowledge can be extended to the design and the realization of optical components such as highly efficient etch-less vertical tapers for passive silicon photonics.

  20. Enhancement of thermal stability of multiwalled carbon nanotubes via different silanization routes

    International Nuclear Information System (INIS)

    Scheibe, B.; Borowiak-Palen, E.; Kalenczuk, R.J.

    2010-01-01

    This work presents an effect of two different silanization procedures on thermal and structural properties of oxidized and oxidized followed by sodium borohydrate (NaBH 4 ) reduction of multiwalled carbon nanotubes (MWCNTs). Purified sample was oxidized in a mixture of nitric and sulfuric acids in a reflux. An oxidized material was divided into two batches. The first batch underwent a silanization procedure directly, while the second batch was reduced by NaBH 4 treatment prior to the silanization. The silanization experiments were performed: (A) with γ-aminopropyltriethoxysilane (APTES) at room temperature in acetone (pH ∼7) and (B) with condensated γ-aminopropyltriethoxysilane at 40 o C in water (pH 4). The extent of the functionalization of the samples after each procedure was examined by Raman spectroscopy. The vibrational properties of the materials were studied via Fourier transform infrared spectroscopy. Boehms titration technique was applied to quantify the amount of the functional groups on MWCNTs. The morphology of the pristine and functionalized carbon nanotubes was exposed to high-resolution transmission electron microscopy analysis. The energy dispersive X-ray (EDX) analysis was used to characterize the elemental composition of each sample. The effect of the silanization process on the thermal properties of MWCNTs was investigated by thermogravimetry analysis. Interestingly, the significant increase of the thermal stability of silanized MWCNTs samples in respect to the pristine MWCNTs was observed.

  1. Study on photon sensitivity of silicon diodes related to materials used for shielding

    International Nuclear Information System (INIS)

    Moiseev, T.

    1999-01-01

    Large area silicon diodes used in electronic neutron dosemeters have a significant over-response to X- and gamma-rays, highly non-linear at photon energies below 200 keV. This over-response to photons is proportional to the diode's active area and strongly affects the neutron sensitivity of such dosemeters. Since silicon diodes are sensitive to light and electromagnetic fields, most diode detector assemblies are provided with a shielding, sometimes also used as radiation filter. In this paper, the influence of materials covering the diode's active area is investigated using the MCNP-4A code by estimating the photon induced pulses in a typical silicon wafer (300 μm thickness and 1 cm diameter) when provided with a front case cover. There have been simulated small-size diode front covers made of several materials with low neutron interaction cross-sections like aluminium, TEFLON, iron and lead. The estimated number of induced pulses in the silicon wafer is calculated for each type of shielding at normal photon incidence for several photon energies from 9.8 keV up to 1.15 MeV and compared with that in a bare silicon wafer. The simulated pulse height spectra show the origin of the photon-induced pulses in silicon for each material used as protective cover: the photoelectric effect for low Z front case materials at low-energy incident photons (up to about 65 keV) and the Compton and build-up effects for high Z case materials at higher photon energies. A simple means to lower and flatten the photon response of silicon diodes over an extended X- and gamma rays energy range is proposed by designing a composed photon filter. (author)

  2. Study on Photon Sensitivity of Silicon Diodes Related to Materials Used for Shielding

    International Nuclear Information System (INIS)

    Moiseev, T.

    2000-01-01

    Large area Silicon diodes used in electronic neutron dosemeters have a significant over-response to X and gamma rays, highly non-linear at photon energies below 200 keV. This over-response to photons is proportional to the diodes active area and strongly affects the neutron sensitivity of such dosemeters. Since Silicon diodes are sensitive to light and electromagnetic fields, most diode detector assemblies are provided with a shielding, sometimes also used as radiation filter. In this paper, the influence of materials covering the diode's active area is investigated using the MCNP-4A code by estimating the photon induced pulses in a typical silicon wafer (300 μm thickness and 1 cm diameter) when provided with a front case cover. There have been simulated small-size diode front covers made of several materials with low neutron interaction cross-sections like aluminium, TEFLON, iron and lead. The estimated number of induced pulses in the silicon wafer is calculated for each type of shielding at normal photon incidence for several photon energies from 9.8 keV up to 1.15 MeV and compared with that in a bare silicon wafer. The simulated pulse height spectra show the origin of the photon induced pulses in silicon for each material used as protective cover: the photoelectric effect for low Z front case materials at low energy incident photons (up to about 65 keV) and the Compton and build-up effects for high Z case materials at higher photon energies. A simple means to lower and flatten the photon response of silicon diodes over an extended X and gamma rays energy range is proposed by designing a composed photon filter. (author)

  3. ESP – Data from Restarted Life Tests of Various Silicon Materials

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Jim

    2010-10-06

    Current funding has allowed the restart of testing of various silicone materials placed in Life Tests or Aging Studies from past efforts. Some of these materials have been in test since 1982, with no testing for approximately 10 years, until funding allowed the restart in FY97. Charts for the various materials at different thickness, compression, and temperature combinations illustrate trends for the load-bearing properties of the materials.

  4. PECVD deposition of device-quality intrinsic amorphous silicon at high growth rate

    Energy Technology Data Exchange (ETDEWEB)

    Carabe, J [Inst. de Energias Renovables, CIEMAT, Madrid (Spain); Gandia, J J [Inst. de Energias Renovables, CIEMAT, Madrid (Spain); Gutierrez, M T [Inst. de Energias Renovables, CIEMAT, Madrid (Spain)

    1993-11-01

    The combined influence of RF-power density (RFP) and silane flow-rate ([Phi]) on the deposition rate of plasma-enhanced chemical vapour deposition (PECVD) intrinsic amorphous silicon has been investigated. The correlation of the results obtained from the characterisation of the material with the silane deposition efficiency, as deduced from mass spectrometry, has led to an interpretation allowing to deposit intrinsic amorphous-silicon films having an optical gap of 1.87 eV and a photoconductive ratio (ratio of ambient-temperature conductivities under 1 sun AM1 and in dark) of 6 orders of magnitude at growth rates up to 10 A/s, without any structural modification of the PECVD system used. Such results are considered of high relevance regarding industrial competitiveness. (orig.)

  5. Silicon carbide-silicon as a support material for oxygen evolution reaction in PEM steam electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Christensen, Erik

    cells. In the present work a commercial SiC-Si, produced by the Acheson process, with a fraction of free silicon around 20% wt. was investigated as a catalyst support for anode electrocatalyst in PEM steam electrolysers. This electrocatalyst system was characterized using several techniques such as XRD......, cyclic voltammetry, SEM, EDX and steady state electrochemical polarisation in a working PEM steam electrolyser. Several SiC-Si-IrO2 electrodes have been prepared and tested. The iridium oxide content at the electrode active layer varied from x=0.2 to x=1, corresponding to the general formula (1-x...... for phosphoric acid doped membrane steam electrolysers....

  6. Macroscopic results for a novel oxygenated silicon material

    International Nuclear Information System (INIS)

    Watts, S.J.; Da Via', C.; Karpenko, A.

    2002-01-01

    High-resistivity FZ silicon diodes have been processed in order to increase their oxygen dimer (O 2i ) concentration. Deep level transient spectroscopy measurements have been performed after proton irradiation showing that the formation of the VO centre is suppressed. The substrates had a starting resistivity of 2-4 kΩ cm, with an oxygen concentration of 10 15 and 10 17 cm -3 . Results for doping changes, leakage current and annealing behaviour after irradiation with 24 GeV/c protons are shown

  7. Process research of non-Czochralski silicon material

    Science.gov (United States)

    Campbell, R. B.

    1986-01-01

    Simultaneous diffusion of liquid precursors containing phosphorus and boron into dendritic web silicon to form solar cell structures was investigated. A simultaneous junction formation techniques was developed. It was determined that to produce high quality cells, an annealing cycle (nominal 800 C for 30 min) should follow the diffusion process to anneal quenched-in defects. Two ohm-cm n-base cells were fabricated with efficiencies greater than 15%. A cost analysis indicated that the simultansous diffusion process costs can be as low as 65% of the costs of the sequential diffusion process.

  8. Macroscopic results for a novel oxygenated silicon material

    CERN Document Server

    Watts, S J; Karpenko, A

    2002-01-01

    High-resistivity FZ silicon diodes have been processed in order to increase their oxygen dimer (O sub 2 sub i) concentration. Deep level transient spectroscopy measurements have been performed after proton irradiation showing that the formation of the VO centre is suppressed. The substrates had a starting resistivity of 2-4 k OMEGA cm, with an oxygen concentration of 10 sup 1 sup 5 and 10 sup 1 sup 7 cm sup - sup 3. Results for doping changes, leakage current and annealing behaviour after irradiation with 24 GeV/c protons are shown.

  9. Implementation Challenges for Sintered Silicon Carbide Fiber Bonded Ceramic Materials for High Temperature Applications

    Science.gov (United States)

    Singh, M.

    2011-01-01

    During the last decades, a number of fiber reinforced ceramic composites have been developed and tested for various aerospace and ground based applications. However, a number of challenges still remain slowing the wide scale implementation of these materials. In addition to continuous fiber reinforced composites, other innovative materials have been developed including the fibrous monoliths and sintered fiber bonded ceramics. The sintered silicon carbide fiber bonded ceramics have been fabricated by the hot pressing and sintering of silicon carbide fibers. However, in this system reliable property database as well as various issues related to thermomechanical performance, integration, and fabrication of large and complex shape components has yet to be addressed. In this presentation, thermomechanical properties of sintered silicon carbide fiber bonded ceramics (as fabricated and joined) will be presented. In addition, critical need for manufacturing and integration technologies in successful implementation of these materials will be discussed.

  10. Silane and Germane Molecular Electronics.

    Science.gov (United States)

    Su, Timothy A; Li, Haixing; Klausen, Rebekka S; Kim, Nathaniel T; Neupane, Madhav; Leighton, James L; Steigerwald, Michael L; Venkataraman, Latha; Nuckolls, Colin

    2017-04-18

    -induced breakdown properties of individual Si-Si, Ge-Ge, Si-O, Si-C, and C-C bonds. Building from these studies, we have prepared a system that has two different, alternative conductance pathways. In this wire, we can intentionally break a labile, strained silicon-silicon bond and thereby shunt the current through the secondary conduction pathway. This type of in situ bond-rupture provides a new tool to study single molecule reactions that are induced by electric fields. Moreover, these studies provide guidance for designing dielectric materials as well as molecular devices that require stability under high voltage bias. The fundamental studies on the structure/function relationships of the molecular wires have guided the design of new functional systems based on the Si- and Ge-based wires. For example, we exploited the principle of strain-induced Lewis acidity from reaction chemistry to design a single molecule switch that can be controllably switched between two conductive states by varying the distance between the tip and substrate electrodes. We found that the strain intrinsic to the disilaacenaphthene scaffold also creates two state conductance switching. Finally, we demonstrate the first example of a stereoelectronic conductance switch, and we demonstrate that the switching relies crucially on the electronic delocalization in Si-Si and Ge-Ge wire backbones. These studies illustrate the untapped potential in using Si- and Ge-based wires to design and control charge transport at the nanoscale and to allow quantum mechanics to be used as a tool to design ultraminiaturized switches.

  11. The effectiveness of silane and siloxane treatments on the superhydrophobicity and icephobicity of concrete surfaces

    Science.gov (United States)

    Rao, Sunil M.

    Icy roads lead to treacherous driving conditions in regions of the U.S., leading to over 450 fatalities per year. De-icing chemicals, such as road salt, leave much to be desired. In this report, commercially available silane, siloxane, and related materials were evaluated as solutions, simple emulsions, and complex emulsions with incorporated particulates, for their effectiveness as superhydrophobic treatments. Through the development and use of a basic impact test, the ease of ice removal (icephobicity) was examined as an application of the targeted superhydrophobicity. A general correlation was found between icephobicity and hydrophobicity, with the amount of ice removed on impact increasing with increasing contact angle. However, the correlation was poor in the high performance region (high contact angle and high ice removal.) Polymethylhydrogensiloxane was a top performer and was more effective when used as a "shell" type emulsion with silica fume particulates. An aqueous sodium methyl siliconate solution showed good performance for ice loss and contact angle, as did a commercial proprietary emulsion using a diethoxyoctylsilyl trimethylsilyl ester of silicic acid. These materials have sterically available functional groups that can react or associate with the concrete surface and are potentially film-forming. Materials with less reactive functional groups and a lower propensity to film-form did not perform as well.

  12. Recent Advances in Photoelectrochemical Applications of Silicon Materials for Solar-to-Chemicals Conversion.

    Science.gov (United States)

    Zhang, Doudou; Shi, Jingying; Zi, Wei; Wang, Pengpeng; Liu, Shengzhong Frank

    2017-11-23

    Photoelectrochemical (PEC) technology for the conversion of solar energy into chemicals requires cost-effective photoelectrodes to efficiently and stably drive anodic and/or cathodic half-reactions to complete the overall reactions for storing solar energy in chemical bonds. The shared properties among semiconducting photoelectrodes and photovoltaic (PV) materials are light absorption, charge separation, and charge transfer. Earth-abundant silicon materials have been widely applied in the PV industry, and have demonstrated their efficiency as alternative photoabsorbers for photoelectrodes. Many efforts have been made to fabricate silicon photoelectrodes with enhanced performance, and significant progress has been achieved in recent years. Herein, recent developments in crystalline and thin-film silicon-based photoelectrodes (including amorphous, microcrystalline, and nanocrystalline silicon) immersed in aqueous solution for PEC hydrogen production from water splitting are summarized, as well as applications in PEC CO 2 reduction and PEC regeneration of discharged species in redox flow batteries. Silicon is an ideal material for the cost-effective production of solar chemicals through PEC methods. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Formation mechanism of a silane-PVA/PVAc complex film on a glass fiber surface.

    Science.gov (United States)

    Repovsky, Daniel; Jane, Eduard; Palszegi, Tibor; Slobodnik, Marek; Velic, Dusan

    2013-10-21

    Mechanical properties of glass fiber reinforced composite materials are affected by fiber sizing. A complex film formation, based on a silane film and PVA/PVAc (polyvinyl alcohol/polyvinyl acetate) microspheres on a glass fiber surface is determined at 1) the nanoscale by using atomic force microscopy (AFM), and 2) the macroscale by using the zeta potential. Silane groups strongly bind through the Si-O-Si bond to the glass surface, which provides the attachment mechanism as a coupling agent. The silane groups form islands, a homogeneous film, as well as empty sites. The average roughness of the silanized surface is 6.5 nm, whereas it is only 0.6 nm for the non-silanized surface. The silane film vertically penetrates in a honeycomb fashion from the glass surface through the deposited PVA/PVAc microspheres to form a hexagonal close pack structure. The silane film not only penetrates, but also deforms the PVA/PVAc microspheres from the spherical shape in a dispersion to a ellipsoidal shape on the surface with average dimensions of 300/600 nm. The surface area value Sa represents an area of PVA/PVAc microspheres that are not affected by the silane penetration. The areas are found to be 0.2, 0.08, and 0.03 μm(2) if the ellipsoid sizes are 320/570, 300/610, and 270/620 nm for silane concentrations of 0, 3.8, and 7.2 μg mL(-1), respectively. The silane film also moves PVA/PVAc microspheres in the process of complex film formation, from the low silane concentration areas to the complex film area providing enough silane groups to stabilize the structure. The values for the residual silane honeycomb structure heights (Ha ) are 6.5, 7, and 12 nm for silane concentrations of 3.8, 7.2, and 14.3 μg mL(-1), respectively. The pH-dependent zeta-potential results suggest a specific role of the silane groups with effects on the glass fiber surface and also on the PVA/PVAc microspheres. The non-silanized glass fiber surface and the silane film have similar zeta potentials ranging

  14. Cobalt nanosheet arrays supported silicon film as anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Huang, X.H.; Wu, J.B.; Cao, Y.Q.; Zhang, P.; Lin, Y.; Guo, R.Q.

    2016-01-01

    Cobalt nanosheet arrays supported silicon film is prepared and used as anode materials for lithium ion batteries. The film is fabricated using chemical bath deposition, hydrogen reduction and radio-frequency magnetron sputtering techniques. The microstructure and morphology are characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). In this composite film, the silicon layer is supported by interconnected aligned cobalt nanosheet arrays that act as the three-dimensional current collector and buffering network. The electrochemical performance as anode materials for lithium ion batteries is investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The results show that the film prepared by sputtering for 1500 s exhibits high capacity, good rate capability and stable cycle ability. It is believed that the cobalt nanosheet arrays play important roles in the electrochemical performance of the silicon layer.

  15. Matrix metalloproteinase sensing via porous silicon microcavity devices functionalized with human antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Marta; Gergely, Csilla [GES-UMR 5650, CNRS, Universite Montpellier 2, Pl. Eugene Bataillon 34095, Montpellier Cedex 5 (France); Taleb Bendiab, Chakib; Massif, Laurent; Cuisinier, Frederic [EA4203, Faculte d' Odontologie, Universite Montpellier 1, Montpellier Cedex 5 (France); Palestino, Gabriela [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Salvador Nava 6, 78000 San Luis Potosi (Mexico); Agarwal, Vivechana [CIICAP, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col Chamilpa, Cuernavaca, Mor. (Mexico)

    2011-06-15

    Porous silicon microcavity (PSiMc) structures were used as support material for specific sensing of matrix metalloproteinases (MMPs). For lower concentrations of MMP-8, the structures were tested with two types of functionalization methods. Silanization of the oxidized porous silicon structures, followed by glutaraldehyde chemistry was found to give very inconsistent results. The use of biotinilated bovine serum albumin linked to the naked PSiMc was found to be an alternative method to attach the anti MMP-8 human antibody, previously modified with streptavidin, which was further used to sense MMP-8 (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Method for Waterproofing Ceramic Materials

    Science.gov (United States)

    Cagliostro, Domenick E. (Inventor); Hsu, Ming-Ta S. (Inventor)

    1998-01-01

    Hygroscopic ceramic materials which are difficult to waterproof with a silane, substituted silane or silazane waterproofing agent, such as an alumina containing fibrous, flexible and porous, fibrous ceramic insulation used on a reentry space vehicle, are rendered easy to waterproof if the interior porous surface of the ceramic is first coated with a thin coating of silica. The silica coating is achieved by coating the interior surface of the ceramic with a silica precursor converting the precursor to silica either in-situ or by oxidative pyrolysis and then applying the waterproofing agent to the silica coated ceramic. The silica precursor comprises almost any suitable silicon containing material such as a silane, silicone, siloxane, silazane and the like applied by solution, vapor deposition and the like. If the waterproofing is removed by e.g., burning, the silica remains and the ceramic is easily rewaterproofed. An alumina containing TABI insulation which absorbs more that five times its weight of water, absorbs less than 10 wt. % water after being waterproofed according to the method of the invention.

  17. Non-fossil reduction materials in the silicon process - properties and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Myrhaug, Edin Henrik

    2003-07-01

    The purpose of this work has been to clarify the effect of using biocarbon as a reduction material in the silicon process. It was decided to compare the biocarbon with fossil carbon and find possible differences both on process performance and eventually on product quality. The elements in the raw materials added to the silicon process goes into three different products: silicon metal, silica dust and into open air. Based on analysis of raw materials and of produced silicon metal and microsilica extensive material balances have been established. One important result from these are the distribution factors that indicate how much of the trace elements that goes into each medium. Another result is that the boiling point of an element or a compound gives a good indication of were it ends. A high boiling point indicates that the element ends up in the silicon metal, while a low boiling point indicates that the element goes with off-gas into air. With an intermediate boiling point, the element goes into the silica dust. The SiO-reactivity of the reduction materials are commonly acknowledged to affect strongly the productivity and consumption figures of the silicon process. Based on data from thermogravimetric experiments with chemical reaction between carbonaceous spheres and SiO-gas, kinetic parameters have been estimated from the shrinking core model for some selected reduction materials of various sizes and spanning a wide range of SiO-reactivity figures. This model describes the degree of conversion versus time for a single sphere where the chemical reaction progresses in a topochemical manner from the outer surface of the solid towards the centre forming a porous product layer around an unreacted shrinking core. This behaviour is for the selected reduction materials to a large extent supported by an investigation of cross section pictures of fully and 50% converted spheres obtained with a microprobe. The estimated kinetic parameters obtained from the

  18. Use of Monocrystalline Silicon as Tool Material for Highly Accurate Blanking of Thin Metal Foils

    International Nuclear Information System (INIS)

    Hildering, Sven; Engel, Ulf; Merklein, Marion

    2011-01-01

    The trend towards miniaturisation of metallic mass production components combined with increased component functionality is still unbroken. Manufacturing these components by forming and blanking offers economical and ecological advantages combined with the needed accuracy. The complexity of producing tools with geometries below 50 μm by conventional manufacturing methods becomes disproportional higher. Expensive serial finishing operations are required to achieve an adequate surface roughness combined with accurate geometry details. A novel approach for producing such tools is the use of advanced etching technologies for monocrystalline silicon that are well-established in the microsystems technology. High-precision vertical geometries with a width down to 5 μm are possible. The present study shows a novel concept using this potential for the blanking of thin copper foils with monocrystallline silicon as a tool material. A self-contained machine-tool with compact outer dimensions was designed to avoid tensile stresses in the brittle silicon punch by an accurate, careful alignment of the punch, die and metal foil. A microscopic analysis of the monocrystalline silicon punch shows appropriate properties regarding flank angle, edge geometry and surface quality for the blanking process. Using a monocrystalline silicon punch with a width of 70 μm blanking experiments on as-rolled copper foils with a thickness of 20 μm demonstrate the general applicability of this material for micro production processes.

  19. Silane surface modification for improved bioadhesion of esophageal stents

    Science.gov (United States)

    Karakoy, Mert; Gultepe, Evin; Pandey, Shivendra; Khashab, Mouen A.; Gracias, David H.

    2014-08-01

    Stent migration occurs in 10-40% of patients who undergo placement of esophageal stents, with higher migration rates seen in those treated for benign esophageal disorders. This remains a major drawback of esophageal stent therapy. In this paper, we propose a new surface modification method to increase the adhesion between self-expandable metallic stents (SEMS) and tissue while preserving their removability. Taking advantage of the well-known affinity between epoxide and amine terminated silane coupling agents with amine and carboxyl groups that are abundant in proteins and related molecules in the human body; we modified the surfaces of silicone coated esophageal SEMS with these adhesive self-assembled monolayers (SAMs). We utilized vapor phase silanization to modify the surfaces of different substrates including PDMS strips and SEMS, and measured the force required to slide these substrates on a tissue piece. Our results suggest that surface modification of esophageal SEMS via covalent attachment of protein-binding coupling agents improves adhesion to tissue and could offer a solution to reduce SEMS migration while preserving their removability.

  20. Preparation and characterisation of immobilised humic acid on silicon wafer

    International Nuclear Information System (INIS)

    Szabo, Gy.; Guczi, J.; Telegdi, J.; Pashalidis, I.; Szymczak, W.; Buckau, G.

    2005-01-01

    Full text of publication follows: The chemistry of the interactions of radionuclides with humic acid needs to be understood in details so that humate-mediated migration of radionuclides through the environment can be predicted. To achieve such a data in microscopic scale, several detective techniques, such as atomic force microscopy (AFM), chemical force microscopy (CFM), nuclear microprobe analysis (NMA) and X-ray photoelectron spectroscopy (XPS) can be used to measure intermolecular forces and to visualize the surface morphology. The main aim of this work was to provide humic material with specific properties in order to study with different spectroscopic techniques, the complexation behaviour of surface bound humic acid in microscopic scale. Namely, humic acid has been immobilised on silicon wafers in order to mimic surface bound humic substances in natural aquatic systems. In this communication, we present a simple protocol to immobilize humic acid on silicon wafer surface. A tri-functional silane reagent 3-amino-propyl-tri-methoxy-silane (APTES) was used to modify the surface of silicon wafers and appeared to be able to strongly attached soluble humic acid through their carboxylic groups to solid support. Characterisation of the surfaces, after any preparation steps, was done by ATR-FTIR, AFM and TOF-SIMS. These methods have proved that the humic acid forms a relatively homogeneous layer on the wafers. Immobilisation of humic acid on silicon wafer was further proved by binding isotherm of Am/Nd. (authors)

  1. Optical switching at 1.55um in silicon racetrack resonators using phase change materials

    NARCIS (Netherlands)

    Rudé, M.; Pello, J.; Simpson, R.E.; Osmond, J.; Roelkens, G.C.; Tol, van der J.J.G.M.; Pruneri, V.

    2013-01-01

    An optical switch operating at a wavelength of 1.55¿µm and showing a 12 dB modulation depth is introduced. The device is implemented in a silicon racetrack resonator using an overcladding layer of the phase change data storage material Ge2Sb2Te5, which exhibits high contrast in its optical

  2. Hydroxyapatites enriched in silicon – Bioceramic materials for biomedical and pharmaceutical applications

    Directory of Open Access Journals (Sweden)

    Katarzyna Szurkowska

    2017-08-01

    Full Text Available Hydroxyapatite (Ca10(PO46(OH2, abbreviated as HA plays a crucial role in implantology, dentistry and bone surgery. Due to its considerable similarity to the inorganic fraction of the mineralized tissues (bones, enamel and dentin, it is used as component in many bone substitutes, coatings of metallic implants and dental materials. Biomaterial engineering often takes advantage of HA capacity for partial ion substitution because the incorporation of different ions in the HA structure leads to materials with improved biological or physicochemical properties. The objective of the work is to provide an overview of current knowledge about apatite materials substituted with silicon ions. Although the exact mechanism of action of silicon in the bone formation process has not been fully elucidated, research has shown beneficial effects of this element on bone matrix mineralization as well as on collagen type I synthesis and stabilization. The paper gives an account of the functions of silicon in bone tissue and outlines the present state of research on synthetic HA containing silicate ions (Si-HA. Finally, methods of HA production as well as potential and actual applications of HA materials modified with silicon ions are discussed.

  3. N-type nano-silicon powders with ultra-low electrical resistivity as anode materials in lithium ion batteries

    Science.gov (United States)

    Yue, Zhihao; Zhou, Lang; Jin, Chenxin; Xu, Guojun; Liu, Liekai; Tang, Hao; Li, Xiaomin; Sun, Fugen; Huang, Haibin; Yuan, Jiren

    2017-06-01

    N-type silicon wafers with electrical resistivity of 0.001 Ω cm were ball-milled to powders and part of them was further mechanically crushed by sand-milling to smaller particles of nano-size. Both the sand-milled and ball-milled silicon powders were, respectively, mixed with graphite powder (silicon:graphite = 5:95, weight ratio) as anode materials for lithium ion batteries. Electrochemical measurements, including cycle and rate tests, present that anode using sand-milled silicon powder performed much better. The first discharge capacity of sand-milled silicon anode is 549.7 mAh/g and it is still up to 420.4 mAh/g after 100 cycles. Besides, the D50 of sand-milled silicon powder shows ten times smaller in particle size than that of ball-milled silicon powder, and they are 276 nm and 2.6 μm, respectively. In addition, there exist some amorphous silicon components in the sand-milled silicon powder excepting the multi-crystalline silicon, which is very different from the ball-milled silicon powder made up of multi-crystalline silicon only.

  4. Fabrication and properties of graphene reinforced silicon nitride composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yaping; Li, Bin, E-mail: libin@nudt.edu.cn; Zhang, Changrui; Wang, Siqing; Liu, Kun; Yang, Bei

    2015-09-17

    Silicon nitride (Si{sub 3}N{sub 4}) ceramic composites reinforced with graphene platelets (GPLs) were prepared by hot pressed sintering and pressureless sintering respectively. Adequate intermixing of the GPLs and the ceramic powders was achieved in nmethyl-pyrrolidone (NMP) under ultrasonic vibration followed by ball-milling. The microstructure and phases of the Si{sub 3}N{sub 4} ceramic composites were investigated by Field Emission Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). The effects of GPLs on the composites' mechanical properties were analyzed. The results showed that GPLs were well dispersed in the Si{sub 3}N{sub 4} ceramic matrix. β-Si{sub 3}N{sub 4,} O′-sialon and GPLs were present in the hot-pressed composites while pressureless sintered composites contain β-Si{sub 3}N{sub 4}, Si, SiC and GPLs. Graphene has the potential to improve the mechanical properties of both the hot pressed and pressureless sintered composites. Toughening effect of GPLs on the pressureless sintered composites appeared more effective than that on the hot pressed composites. Toughening mechanisms, such as pull-out, crack bridging and crack deflection induced by GPLs were observed in the composites prepared by the two methods.

  5. Bioactive silicon nitride: A new therapeutic material for osteoarthropathy

    Science.gov (United States)

    Pezzotti, Giuseppe; Marin, Elia; Adachi, Tetsuya; Rondinella, Alfredo; Boschetto, Francesco; Zhu, Wenliang; Sugano, Nobuhiko; Bock, Ryan M.; McEntire, Bryan; Bal, Sonny B.

    2017-03-01

    While the reciprocity between bioceramics and living cells is complex, it is principally governed by the implant’s surface chemistry. Consequently, a deeper understanding of the chemical interactions of bioceramics with living tissue could ultimately lead to new therapeutic strategies. However, the physical and chemical principles that govern these interactions remain unclear. The intricacies of this biological synergy are explored within this paper by examining the peculiar surface chemistry of a relatively new bioceramic, silicon nitride (Si3N4). Building upon prior research, this paper aims at obtaining new insights into the biological interactions between Si3N4 and living cells, as a consequence of the off-stoichiometric chemical nature of its surface at the nanometer scale. We show here yet unveiled details of surface chemistry and, based on these new data, formulate a model on how, ultimately, Si3N4 influences cellular signal transduction functions and differentiation mechanisms. In other words, we interpret its reciprocity with living cells in chemical terms. These new findings suggest that Si3N4 might provide unique new medicinal therapies and effective remedies for various bone or joint maladies and diseases.

  6. Fabrication and properties of graphene reinforced silicon nitride composite materials

    International Nuclear Information System (INIS)

    Yang, Yaping; Li, Bin; Zhang, Changrui; Wang, Siqing; Liu, Kun; Yang, Bei

    2015-01-01

    Silicon nitride (Si 3 N 4 ) ceramic composites reinforced with graphene platelets (GPLs) were prepared by hot pressed sintering and pressureless sintering respectively. Adequate intermixing of the GPLs and the ceramic powders was achieved in nmethyl-pyrrolidone (NMP) under ultrasonic vibration followed by ball-milling. The microstructure and phases of the Si 3 N 4 ceramic composites were investigated by Field Emission Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). The effects of GPLs on the composites' mechanical properties were analyzed. The results showed that GPLs were well dispersed in the Si 3 N 4 ceramic matrix. β-Si 3 N 4, O′-sialon and GPLs were present in the hot-pressed composites while pressureless sintered composites contain β-Si 3 N 4 , Si, SiC and GPLs. Graphene has the potential to improve the mechanical properties of both the hot pressed and pressureless sintered composites. Toughening effect of GPLs on the pressureless sintered composites appeared more effective than that on the hot pressed composites. Toughening mechanisms, such as pull-out, crack bridging and crack deflection induced by GPLs were observed in the composites prepared by the two methods

  7. Plasmonic silicon solar cells: impact of material quality and geometry.

    Science.gov (United States)

    Pahud, Celine; Isabella, Olindo; Naqavi, Ali; Haug, Franz-Josef; Zeman, Miro; Herzig, Hans Peter; Ballif, Christophe

    2013-09-09

    We study n-i-p amorphous silicon solar cells with light-scattering nanoparticles in the back reflector. In one configuration, the particles are fully embedded in the zinc oxide buffer layer; In a second configuration, the particles are placed between the buffer layer and the flat back electrode. We use stencil lithography to produce the same periodic arrangement of the particles and we use the same solar cell structure on top, thus establishing a fair comparison between a novel plasmonic concept and its more traditional counterpart. Both approaches show strong resonances around 700 nm in the external quantum efficiency the position and intensity of which vary strongly with the nanoparticle shape. Moreover, disagreement between simulations and our experimental results suggests that the dielectric data of bulk silver do not correctly represent the reality. A better fit is obtained by introducing a porous interfacial layer between the silver and zinc oxide. Without the interfacial layer, e.g. by improved processing of the nanoparticles, our simulations show that the nanoparticles concept could outperform traditional back reflectors.

  8. Temperature and humidity effect on aging of silicone rubbers as sealing materials for proton exchange membrane fuel cell applications

    International Nuclear Information System (INIS)

    Chang, Huawei; Wan, Zhongmin; Chen, Xi; Wan, Junhua; Luo, Liang; Zhang, Haining; Shu, Shuiming; Tu, Zhengkai

    2016-01-01

    Highlights: • Aging of silicone rubbers with different hardness was investigated. • Existed water molecules from humidified gases can accelerate the aging process. • Silicone rubber with hardness of 40 is more suitable as sealing materials. • Silicone rubbers can be used as sealing materials below 80 °C but not above 100 °C. - Abstract: Durability and reliability of seals around perimeter of each unit are critical to the lifetime of proton exchange membrane fuel cells. In this study, we investigate the aging of silicone rubbers with different hardness, often used as sealing materials for fuel cells, subjected to dry and humidified air at different temperatures. The aging properties are characterized by variation of permanent compression set value under compression, mechanical properties, and surface morphology as well. The results show that aging of silicone rubbers becomes more severe with the increase in subjected temperature. At temperature above 100 °C, silicone rubbers are not suitable for fuel cell applications. The existed water molecules from humidified gases can accelerate the aging of silicone rubbers. Among the tested samples, silicone rubber with hardness of 40 is more durable than that with hardness of 30 and 50 for fuel cells. The change of chemical structure after aging suggests that the aging of silicone rubbers mainly results from the chemical decomposition of cross-linker units for connection of polysiloxane backbones and of methyl groups attached to silicon atoms.

  9. Self-assembled peptide nanotubes as an etching material for the rapid fabrication of silicon wires

    DEFF Research Database (Denmark)

    Larsen, Martin Benjamin Barbour Spanget; Andersen, Karsten Brandt; Svendsen, Winnie Edith

    2011-01-01

    This study has evaluated self-assembled peptide nanotubes (PNTS) and nanowires (PNWS) as etching mask materials for the rapid and low-cost fabrication of silicon wires using reactive ion etching (RIE). The self-assembled peptide structures were fabricated under mild conditions and positioned on c...... characterization by SEM and I-V measurements. Additionally, the fabricated silicon structures were functionalized with fluorescent molecules via a biotin-streptavidin interaction in order to probe their potential in the development of biosensing devices....

  10. Work plan for testing silicone impression material and fixture on pool cell capsule

    International Nuclear Information System (INIS)

    Lundeen, J.E.

    1994-01-01

    The purpose of this work plan is to provide a safe procedure to test a cesium capsule impression fixture at Waste Encapsulation and Storage Facility (WESF). The impression will be taken with silicone dental impression material pressed down upon the capsule using the impression fixture. This test will evaluate the performance of the fixture and impression material under high radiation and temperature conditions on a capsule in a WESF pool cell

  11. Silicon oxide based high capacity anode materials for lithium ion batteries

    Science.gov (United States)

    Deng, Haixia; Han, Yongbong; Masarapu, Charan; Anguchamy, Yogesh Kumar; Lopez, Herman A.; Kumar, Sujeet

    2017-03-21

    Silicon oxide based materials, including composites with various electrical conductive compositions, are formulated into desirable anodes. The anodes can be effectively combined into lithium ion batteries with high capacity cathode materials. In some formulations, supplemental lithium can be used to stabilize cycling as well as to reduce effects of first cycle irreversible capacity loss. Batteries are described with surprisingly good cycling properties with good specific capacities with respect to both cathode active weights and anode active weights.

  12. Bulk solar grade silicon: how chemistry and physics play to get a benevolent microstructured material

    Energy Technology Data Exchange (ETDEWEB)

    Pizzini, S. [University of Milano-Bicocca, Department of Materials Science, Milan (Italy); Nedsilicon SpA, Osimo, Ancona (Italy)

    2009-07-15

    The availability of low-cost alternatives to electronic grade silicon has been and still is the condition for the extensive use of photovoltaics as an efficient sun harvesting system. The first step towards this objective was positively carried out in the 1980s and resulted in the reduction in cost and energy of the growth process using as feedstock electronic grade scraps and a variety of solidification procedures, all of which deliver a multi-crystalline material of high photovoltaic quality. The second step was an intense R and D activity aiming at defining and developing at lab scale a new variety of silicon, called ''solar grade'' silicon, which should fulfil the requirement of both cost effectiveness and high conversion efficiency. The third step involved and still involves the development of cost-effective technologies for the manufacture of solar grade silicon, in alternative to the classical Siemens route, which relays, as is well-known, to the pyrolitic decomposition of high-purity trichlorosilane and which is, also in its more advanced versions, extremely energy intensive. Aim of this paper is to give the author's viewpoint about some open questions concerning bulk solar silicon for PV applications and about challenges and chances of novel feedstocks of direct metallurgical origin. (orig.)

  13. Effective Chemical Route to 2D Nanostructured Silicon Electrode Material: Phase Transition from Exfoliated Clay Nanosheet to Porous Si Nanoplate

    International Nuclear Information System (INIS)

    Adpakpang, Kanyaporn; Patil, Sharad B.; Oh, Seung Mi; Kang, Joo-Hee; Lacroix, Marc; Hwang, Seong-Ju

    2016-01-01

    Graphical abstract: Effective morphological control of porous silicon 2D nanoplate can be achieved by the magnesiothermically-induced phase transition of exfoliated silicate clay nanosheets. The promising lithium storage performance of the obtained silicon materials with huge capacity and excellent rate characteristics underscores the prime importance of porously 2D nanostructured morphology of silicon. - Highlights: • 2D nanostructured silicon electrode materials are successfully synthesized via the magnesiothermically-induced phase transition of exfoliated clay 2D nanosheets. • High discharge capacity and rate capability are achieved from the 2D nanoplates of silicon. • Silicon 2D nanoplates can enhance both Li"+ diffusion and charge-transfer kinetics. • 2D nanostructured silicon is beneficial for the cycling stability by minimizing the volume change during lithiation-delithiation. - Abstract: An efficient and economical route for the synthesis of porous two-dimensional (2D) nanoplates of silicon is developed via the magnesiothermically-induced phase transition of exfoliated clay 2D nanosheets. The magnesiothermic reaction of precursor clay nanosheets prepared by the exfoliation and restacking with Mg"2"+ cations yields porous 2D nanoplates of elemental silicon. The variation in the Mg:SiO_2 ratio has a significant effect on the porosity and connectivity of silicon nanoplates. The porous silicon nanoplates show a high discharge capacity of 2000 mAh g"−"1 after 50 cycles. Of prime importance is that this electrode material still retains a large discharge capacity at higher C-rates, which is unusual for the elemental silicon electrode. This is mainly attributed to the improved diffusion of lithium ions, charge-transfer kinetics, and the preservation of the electrical connection of the porous 2D plate-shaped morphology. This study highlights the usefulness of clay mineral as an economical and scalable precursor of high-performance silicon electrodes with

  14. Fluorescent silicon carbide materials for white LEDs and photovoltaics

    DEFF Research Database (Denmark)

    Syväjärvi, Mikael; Ou, Haiyan; Wellmann, Peter

    the luminescence appears in the infrared region in a broad range from 700 to 1100 nm. This potentially can be used to develop an infrared LED for de-icing in wind power and airplanes, or medical applications. Further on, a very efficient solar cell material can be investigated by studying the impurity effect...

  15. Effects of material non-linearity on the residual stresses in a dendritic silicon crystal ribbon

    Science.gov (United States)

    Ray, Sujit K.; Utku, Senol

    1990-01-01

    Thermal stresses developed in a dendritic silicon crystal ribbon have been shown to cause plastic deformation and residual stresses in the ribbon. This paper presents an implementation of a numerical model proposed for thermoelastoplastic behavior of a material. The model has been used to study the effects of plasticity of silicon on the residual stresses. The material properties required to implement this model are all assumed, and the response of the material to the variations in these assumed parameters of the constitutive law and in the finite element mesh is investigated. The steady state growth process is observed to be periodic with nonzero residual stresses. Numerical difficulties are also encountered in the computer solution process, resulting in sharp jumps and large oscillations in the stress responses.

  16. Resistance of poly(ethylene oxide)-silane monolayers to the growth of polyelectrolyte multilayers.

    Science.gov (United States)

    Buron, Cédric C; Callegari, Vincent; Nysten, Bernard; Jonas, Alain M

    2007-09-11

    The ability of poly(ethylene oxide)-silane (PEO-silane) monolayers grafted onto silicon surfaces to resist the growth of polyelectrolyte multilayers under various pH conditions is assessed for different pairs of polyelectrolytes of varying molar mass. For acidic conditions (pH 3), the PEO-silane monolayers exhibit good polyelectrolyte repellency provided the polyelectrolytes bear no moieties that are able to form hydrogen bonds with the ether groups of the PEO chains. At basic pH, PEO-silane monolayers undergo substantial hydrolysis leading to the formation of negatively charged defects in the monolayers, which then play the role of adsorption sites for the polycation. Once the polycation is adsorbed, multilayer growth ensues. Because this is defect-driven growth, the multilayer is not continuous and is made of blobs or an open network of adsorbed strands. For such conditions, the molar mass of the polyelectrolyte plays a key role, with polyelectrolyte chains of larger molar mass adsorbing on a larger number of defects, resulting in stronger anchoring of the polyelectrolyte complex on the surfaces and faster subsequent growth of the multilayer. For polyelectrolytes of sufficiently low molar mass at pH 9, the growth of the multilayer can nevertheless be prevented for as much as five cycles of deposition.

  17. Amorphous silicon films doped with BF3 and PF5

    International Nuclear Information System (INIS)

    Ortiz, A.; Muhl, S.; Sanchez, A.; Monroy, R.; Pickin, W.

    1984-01-01

    By using gaseous discharge process, thin films of hydrogenated amorphous silicon (a-Si:H) were produced. This process consists of Silane (SiH 4 ) decomposition at low pressure, in a chamber. (A.C.A.S.) [pt

  18. Vertically aligned CNT-Cu nano-composite material for stacked through-silicon-via interconnects.

    Science.gov (United States)

    Sun, Shuangxi; Mu, Wei; Edwards, Michael; Mencarelli, Davide; Pierantoni, Luca; Fu, Yifeng; Jeppson, Kjell; Liu, Johan

    2016-08-19

    For future miniaturization of electronic systems using 3D chip stacking, new fine-pitch materials for through-silicon-via (TSV) applications are likely required. In this paper, we propose a novel carbon nanotube (CNT)/copper nanocomposite material consisting of high aspect ratio, vertically aligned CNT bundles coated with copper. These bundles, consisting of hundreds of tiny CNTs, were uniformly coated by copper through electroplating, and aspect ratios as high as 300:1 were obtained. The resistivity of this nanomaterial was found to be as low as ∼10(-8) Ω m, which is of the same order of magnitude as the resistivity of copper, and its temperature coefficient was found to be only half of that of pure copper. The main advantage of the composite TSV nanomaterial is that its coefficient of thermal expansion (CTE) is similar to that of silicon, a key reliability factor. A finite element model was set up to demonstrate the reliability of this composite material and thermal cycle simulations predicted very promising results. In conclusion, this composite nanomaterial appears to be a very promising material for future 3D TSV applications offering both a low resistivity and a low CTE similar to that of silicon.

  19. Fine pitch and low material readout bus in the Silicon Pixel Vertex Tracker for the PHENIX Vertex Tracker upgrade

    International Nuclear Information System (INIS)

    Fujiwara, Kohei

    2010-01-01

    The construction of the Silicon Pixel Detector is starting in spring 2009 as project of the RHIC-PHENIX Silicon Vertex Tracker (VTX) upgrade at the Brookhaven National Laboratory. For the construction, we have developed a fine pitch and low material readout bus as the backbone parts of the VTX. In this article, we report the development and production of the readout bus.

  20. Electrochemical characterization of carbon coated bundle-type silicon nanorod for anode material in lithium ion secondary batteries

    International Nuclear Information System (INIS)

    Halim, Martin; Kim, Jung Sub; Choi, Jeong-Gil; Lee, Joong Kee

    2015-01-01

    Highlights: • Bundle-type silicon nanorods (BSNR) were synthesized by metal assisted chemical etching. • Novel bundle-type nanorods electrode showed self-relaxant characteristics. • The self-relaxant property was enhanced by increasing the silver concentration. • PAA binder enhanced the self-relaxant property of the silicon material. • Carbon coated BSNR (BSNR@C) has evidently provided better cycle performance. - Abstract: Nanostructured silicon synthesis by surface modification of commercial micro-powder silicon was investigated in order to reduce the maximum volume change over cycle. The surface of micro-powder silicon was modified using an Ag metal-assisted chemical etching technique to produce nanostructured material in the form of bundle-type silicon nanorods. The volume change of the electrode using the nanostructured silicon during cycle was investigated using an in-situ dilatometer. Our result shows that nanostructured silicon synthesized using this method showed a self-relaxant characteristic as an anode material for lithium ion battery application. Moreover, binder selection plays a role in enhancing self-relaxant properties during delithiation via strong hydrogen interaction on the surface of the silicon material. The nanostructured silicon was then coated with carbon from propylene gas and showed higher capacity retention with the use of polyacrylic acid (PAA) binder. While the nano-size of the pore diameter control may significantly affect the capacity fading of nanostructured silicon, it can be mitigated via carbon coating, probably due to the prevention of Li ion penetration into 10 nano-meter sized pores

  1. Electrochemical characterization of carbon coated bundle-type silicon nanorod for anode material in lithium ion secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Halim, Martin [Center for Energy Convergence, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Energy and Environmental Engineering, Korea University of Science and Technology, Gwahangno, Yuseong-gu, Daejeon, 305-333 (Korea, Republic of); Kim, Jung Sub [Center for Energy Convergence, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Department of Material Science & Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Choi, Jeong-Gil [Department of Chemical Engineering, Hannam University, 461-1 Junmin-dong, Yusung-gu, Taejon 305-811 (Korea, Republic of); Lee, Joong Kee, E-mail: leejk@kist.re.kr [Center for Energy Convergence, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Energy and Environmental Engineering, Korea University of Science and Technology, Gwahangno, Yuseong-gu, Daejeon, 305-333 (Korea, Republic of)

    2015-04-15

    Highlights: • Bundle-type silicon nanorods (BSNR) were synthesized by metal assisted chemical etching. • Novel bundle-type nanorods electrode showed self-relaxant characteristics. • The self-relaxant property was enhanced by increasing the silver concentration. • PAA binder enhanced the self-relaxant property of the silicon material. • Carbon coated BSNR (BSNR@C) has evidently provided better cycle performance. - Abstract: Nanostructured silicon synthesis by surface modification of commercial micro-powder silicon was investigated in order to reduce the maximum volume change over cycle. The surface of micro-powder silicon was modified using an Ag metal-assisted chemical etching technique to produce nanostructured material in the form of bundle-type silicon nanorods. The volume change of the electrode using the nanostructured silicon during cycle was investigated using an in-situ dilatometer. Our result shows that nanostructured silicon synthesized using this method showed a self-relaxant characteristic as an anode material for lithium ion battery application. Moreover, binder selection plays a role in enhancing self-relaxant properties during delithiation via strong hydrogen interaction on the surface of the silicon material. The nanostructured silicon was then coated with carbon from propylene gas and showed higher capacity retention with the use of polyacrylic acid (PAA) binder. While the nano-size of the pore diameter control may significantly affect the capacity fading of nanostructured silicon, it can be mitigated via carbon coating, probably due to the prevention of Li ion penetration into 10 nano-meter sized pores.

  2. Gold nanorods-silicone hybrid material films and their optical limiting property

    Science.gov (United States)

    Li, Chunfang; Qi, Yanhai; Hao, Xiongwen; Peng, Xue; Li, Dongxiang

    2015-10-01

    As a kind of new optical limiting materials, gold nanoparticles have optical limiting property owing to their optical nonlinearities induced by surface plasmon resonance (SPR). Gold nanorods (GNRs) possess transversal SPR absorption and tunable longitudinal SPR absorption in the visible and near-infrared region, so they can be used as potential optical limiting materials against tunable laser pulses. In this letter, GNRs were prepared using seed-mediated growth method and surface-modified by silica coating to obtain good dispersion in polydimethylsiloxane prepolymers. Then the silicone rubber films doped with GNRs were prepared after vulcanization, whose optical limiting property and optical nonlinearity were investigated. The silicone rubber samples doped with more GNRs were found to exhibit better optical limiting performance.

  3. The Microwave Noise Behaviour Of Dual Material Gate Silicon On Insulator

    Science.gov (United States)

    Jafar, N.; Soin, N.

    2009-06-01

    This work presents the noise behaviour due to the applied Dual Material Gate (DMG) on the 75 nm n-channel Silicon On Insulator (SOI) device operating in the fully depletion mode, particularly for microwave circuit design. Influences of DMG properties namely the gate length ratio (L1:L2) and gate material workfunction difference (ΔΦM) as well as structural and operational parameters which are silicon thickness (TSi) and threshold voltage (VTH) setting variation on the noise performance were carried out on simulation basis using ATLAS 2D. Results show better noise performance in DMG as compare to the standard gate structure of FD-SOI devices. Higher VTH for DMG design is recommended for minimized noise figure in line with the advantage of inverse VTH roll-off characteristics for short channel effects suppression.

  4. Fine defective structure of silicon carbide powders obtained from different starting materials

    Directory of Open Access Journals (Sweden)

    Tomila T.V.

    2006-01-01

    Full Text Available The fine defective structure of silicon carbide powders obtained from silicic acid-saccharose, aerosil-saccharose, aerosil-carbon black, and hydrated cellulose-silicic acid gel systems was investigated. The relation between IR absorption characteristics and the microstructure of SiC particles obtained from different starting materials was established. The numerical relationship between the lattice parameter a and the frequency νTO is presented.

  5. Influence of ion bombardment on microcrystalline silicon material quality and solar cell performances

    OpenAIRE

    Bugnon, G; Feltrin, A; Sculati-Meillaud, F; Bailat, J; Ballif, C

    2008-01-01

    Microcrystalline hydrogenated silicon growth with VHF-PECVD was examined in an industrial type parallel plate KAITM reactor. The influence of pressure on material quality was studied in single junction solar cells. Solar cells with their intrinsic layer prepared at higher pressures exhibit remarkable improvements, reaching 8.2% efficiency at 3.5 mbar. Further analyzes showed that μc- Si:H intrinsic layers grown at higher pressures have a significantly lower defect density. These results are a...

  6. 17th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Workshop Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B. L.

    2007-08-01

    The National Center for Photovoltaics sponsored the 17th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, held in Vail, CO, August 5-8, 2007. This meeting provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The theme of this year's meeting was 'Expanding Technology for a Future Powered by Si Photovoltaics.'

  7. High-precision drop shape analysis (HPDSA) of quasistatic contact angles on silanized silicon wafers with different surface topographies during inclining-plate measurements: Influence of the surface roughness on the contact line dynamics

    International Nuclear Information System (INIS)

    Heib, F.; Hempelmann, R.; Munief, W.M.; Ingebrandt, S.; Fug, F.; Possart, W.; Groß, K.; Schmitt, M.

    2015-01-01

    Highlights: • Analysis of the triple line motion on surfaces with nanoscale surface topographies. • Analysis of the triple line motion is performed in sub-pixel resolution. • A special fitting and statistical approach for contact angle analysis is applied. • The analyses result set of contact angle data which is independent of “user-skills”. • Characteristically density distributions in dependence on the surface properties. - Abstract: Contact angles and wetting of solid surfaces are strongly influenced by the physical and chemical properties of the surfaces. These influence quantities are difficult to distinguish from each other if contact angle measurements are performed by measuring only the advancing θ a and the receding θ r contact angle. In this regard, time-dependent water contact angles are measured on two hydrophobic modified silicon wafers with different physical surface topographies. The first surface is nearly atomically flat while the second surface is patterned (alternating flat and nanoscale rough patterns) which is synthesized by a photolithography and etching procedure. The different surface topographies are characterized with atomic force microscopy (AFM), Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) and Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR). The resulting set of contact angle data obtained by the high-precision drop shape analysis approach is further analyzed by a Gompertzian fitting procedure and a statistical counting procedure in dependence on the triple line velocity. The Gompertzian fit is used to analyze overall properties of the surface and dependencies between the motion on the front and the back edge of the droplets. The statistical counting procedure results in the calculation of expectation values E(p) and standard deviations σ(p) for the inclination angle φ, contact angle θ, triple line velocity vel and the covered distance of the triple line dis

  8. High-precision drop shape analysis (HPDSA) of quasistatic contact angles on silanized silicon wafers with different surface topographies during inclining-plate measurements: Influence of the surface roughness on the contact line dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Heib, F., E-mail: f.heib@mx.uni-saarland.de [Department of Physical Chemistry, Saarland University, 66123 Saarbrücken (Germany); Hempelmann, R. [Department of Physical Chemistry, Saarland University, 66123 Saarbrücken (Germany); Munief, W.M.; Ingebrandt, S. [Department of Informatics and Microsystem Technology, University of Applied Sciences, Kaiserslautern, 66482 Zweibrücken (Germany); Fug, F.; Possart, W. [Department of Adhesion and Interphases in Polymers, Saarland University, 66123 Saarbrücken (Germany); Groß, K.; Schmitt, M. [Department of Physical Chemistry, Saarland University, 66123 Saarbrücken (Germany)

    2015-07-01

    Highlights: • Analysis of the triple line motion on surfaces with nanoscale surface topographies. • Analysis of the triple line motion is performed in sub-pixel resolution. • A special fitting and statistical approach for contact angle analysis is applied. • The analyses result set of contact angle data which is independent of “user-skills”. • Characteristically density distributions in dependence on the surface properties. - Abstract: Contact angles and wetting of solid surfaces are strongly influenced by the physical and chemical properties of the surfaces. These influence quantities are difficult to distinguish from each other if contact angle measurements are performed by measuring only the advancing θ{sub a} and the receding θ{sub r} contact angle. In this regard, time-dependent water contact angles are measured on two hydrophobic modified silicon wafers with different physical surface topographies. The first surface is nearly atomically flat while the second surface is patterned (alternating flat and nanoscale rough patterns) which is synthesized by a photolithography and etching procedure. The different surface topographies are characterized with atomic force microscopy (AFM), Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) and Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR). The resulting set of contact angle data obtained by the high-precision drop shape analysis approach is further analyzed by a Gompertzian fitting procedure and a statistical counting procedure in dependence on the triple line velocity. The Gompertzian fit is used to analyze overall properties of the surface and dependencies between the motion on the front and the back edge of the droplets. The statistical counting procedure results in the calculation of expectation values E(p) and standard deviations σ(p) for the inclination angle φ, contact angle θ, triple line velocity vel and the covered distance of the triple

  9. Experimental investigation on material migration phenomena in micro-EDM of reaction-bonded silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Liew, Pay Jun [Department of Mechanical Systems and Design, Tohoku University, Aramaki Aoba 6-6-01, Aoba-ku, Sendai, 980-8579 (Japan); Manufacturing Process Department, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100, Durian Tunggal, Melaka (Malaysia); Yan, Jiwang, E-mail: yan@mech.keio.ac.jp [Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Hiyoshi 3-14-1, Kohoku-ku, Yokohama, 223-8522 (Japan); Kuriyagawa, Tsunemoto [Department of Mechanical Systems and Design, Tohoku University, Aramaki Aoba 6-6-01, Aoba-ku, Sendai, 980-8579 (Japan)

    2013-07-01

    Material migration between tool electrode and workpiece material in micro electrical discharge machining of reaction-bonded silicon carbide was experimentally investigated. The microstructural changes of workpiece and tungsten tool electrode were examined using scanning electron microscopy, cross sectional transmission electron microscopy and energy dispersive X-ray under various voltage, capacitance and carbon nanofibre concentration in the dielectric fluid. Results show that tungsten is deposited intensively inside the discharge-induced craters on the RB-SiC surface as amorphous structure forming micro particles, and on flat surface region as a thin interdiffusion layer of poly-crystalline structure. Deposition of carbon element on tool electrode was detected, indicating possible material migration to the tool electrode from workpiece material, carbon nanofibres and dielectric oil. Material deposition rate was found to be strongly affected by workpiece surface roughness, voltage and capacitance of the electrical discharge circuit. Carbon nanofibre addition in the dielectric at a suitable concentration significantly reduced the material deposition rate.

  10. Experimental investigation on material migration phenomena in micro-EDM of reaction-bonded silicon carbide

    International Nuclear Information System (INIS)

    Liew, Pay Jun; Yan, Jiwang; Kuriyagawa, Tsunemoto

    2013-01-01

    Material migration between tool electrode and workpiece material in micro electrical discharge machining of reaction-bonded silicon carbide was experimentally investigated. The microstructural changes of workpiece and tungsten tool electrode were examined using scanning electron microscopy, cross sectional transmission electron microscopy and energy dispersive X-ray under various voltage, capacitance and carbon nanofibre concentration in the dielectric fluid. Results show that tungsten is deposited intensively inside the discharge-induced craters on the RB-SiC surface as amorphous structure forming micro particles, and on flat surface region as a thin interdiffusion layer of poly-crystalline structure. Deposition of carbon element on tool electrode was detected, indicating possible material migration to the tool electrode from workpiece material, carbon nanofibres and dielectric oil. Material deposition rate was found to be strongly affected by workpiece surface roughness, voltage and capacitance of the electrical discharge circuit. Carbon nanofibre addition in the dielectric at a suitable concentration significantly reduced the material deposition rate.

  11. Bacterial adhesion to conventional hydrogel and new silicone-hydrogel contact lens materials.

    Science.gov (United States)

    Kodjikian, Laurent; Casoli-Bergeron, Emmanuelle; Malet, Florence; Janin-Manificat, Hélène; Freney, Jean; Burillon, Carole; Colin, Joseph; Steghens, Jean-Paul

    2008-02-01

    As bacterial adhesion to contact lenses may contribute to the pathogenesis of keratitis, the aim of our study was to investigate in vitro adhesion of clinically relevant bacteria to conventional hydrogel (standard HEMA) and silicone-hydrogel contact lenses using a bioluminescent ATP assay. Four types of unworn contact lenses (Etafilcon A, Galyfilcon A, Balafilcon A, Lotrafilcon B) were incubated with Staphylococcus epidermidis (two different strains) and Pseudomonas aeruginosa suspended in phosphate buffered saline (PBS). Lenses were placed with the posterior surface facing up and were incubated in the bacterial suspension for 4 hours at 37 degrees C. Bacterial binding was then measured and studied by bioluminescent ATP assay. Six replicate experiments were performed for each lens and strain. Adhesion of all species of bacteria to standard HEMA contact lenses (Etafilcon A) was found to be significantly lower than that of three types of silicone-hydrogel contact lenses, whereas Lotrafilcon B material showed the highest level of bacterial binding. Differences between species in the overall level of adhesion to the different types of contact lenses were observed. Adhesion of P. aeruginosa was typically at least 20 times greater than that observed with both S. epidermidis strains. Conventional hydrogel contact lenses exhibit significantly lower bacterial adhesion in vitro than silicone-hydrogel ones. This could be due to the greater hydrophobicity but also to the higher oxygen transmissibility of silicone-hydrogel lenses.

  12. Trace elements determination in silicon and ferrosilicon reference materials by instrumental neutron activation analysis method

    International Nuclear Information System (INIS)

    Moreira, Edson Goncalves; Vasconcellos, Marina Beatriz Agostini; Saiki, Mitiko; Iamashita, Celia Omine

    2002-01-01

    The use of certified reference materials, CRM, is of uppermost importance in the rastreability realization of the measurement process. At times, CRM use is restricted by the non existence of a suitable CRM with similarity to the sample in respect to matrix composition or with element levels in different orders of magnitude. IPT Chemical Division launched a project to prepare a metallic silicon CRM, due to the requirements of the industries in this field. To characterize this new CRM, IPEN Nuclear Reactor Center is able to perform instrumental neutron activation analysis, INAA, a very suitable method for silicon matrix samples because they produce basically the short lived radionuclide 3 1 Si under thermal neutrons flux, which after radioactive decay, does not interfere in the determination of other elements. In this paper, it is presented the determination of As, Br, Co, Cr, K, Eu, Fe, La, Mn, Na Nb, Sb, Sm, Sc, Th, Tb, U, V, W and Yb in silicon CRM NBS SRM 57; ferrosilicon CRM IPT 56; IPT 70; NBS SRM 58a; NBS SRM 59a and silicon RM under preparation IPT 132. From the results, the accuracy and the precision of the process were assessed. (author)

  13. [Influence of autoclave sterilization on dimensional stability and detail reproduction of 5 additional silicone impression materials].

    Science.gov (United States)

    Xu, Tong-kai; Sun, Zhi-hui; Jiang, Yong

    2012-03-01

    To evaluate the dimensional stability and detail reproduction of five additional silicone impression materials after autoclave sterilization. Impressions were made on the ISO 4823 standard mold containing several marking lines, in five kinds of additional silicone. All the impressions were sterilized by high temperature and pressure (135 °C, 212.8 kPa) for 25 min. Linear measurements of pre-sterilization and post-sterilization were made with a measuring microscope. Statistical analysis utilized single-factor analysis with pair-wise comparison of mean values when appropriate. Hypothesis testing was conducted at alpha = 0.05. No significant difference was found between the pre-sterilization and post-sterilization conditions for all locations, and all the absolute valuse of linear rate of change less than 8%. All the sterilization by the autoclave did not affect the surfuce detail reproduction of the 5 impression materials. The dimensional stability and detail reproduction of the five additional silicone impression materials in the study was unaffected by autoclave sterilization.

  14. Final report. Fabrication of silicon carbide/silicon nitride nanocomposite materials and characterization of their performance; Herstellung von Siliciumcarbid/Siliciumnitrid-Nanocomposite-Werkstoffen und Charakterisierung ihrer Leistungsfaehigkeit. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Westerheide, R.; Woetting, G.; Schmitz, H.W.

    1998-07-01

    The presented activities were initiated by the well known publications of Niihara and Ishizaki. There, the strengthening and toughening of silicon nitride by nanoscaled silicon carbide particles are described. Both authors have used expensive powder production routes to achieve the optimum mechanical properties. However, for a commercial purpose these routes are not applicable due to their high cost and low reproducibility. The production route chosen by H.C. Starck together with CFI and the Fraunhofer-Institute is a powder synthesis based on the carbothermal reaction of silicon nitride as a low cost synthesis method. The investigations were performed for materials made from synthesis powders and other reference materials. The materials were densified with relatively high amounts of conventional sintering additives by gas pressure sintering. It is shown, that the postulated maxima of strength and fracture toughness behaviour at room temperature with maxima at about 5% to 25% nanoscaled SiC cannot be achieved. However, the mechanical high temperature material behaviour is as good as the behaviour of highly developed silicon nitride materials, which are produced by HIP or by consequent minimisation of the additive content with the well known difficulties to densify these materials. An overview will be given here on the powder production route and their specific problems, the mechanical properties, the microstructure and the possible effects of the microstructure, which result in an improvement of the creep resistance. (orig.)

  15. Hybrid sol-gel optical materials

    Science.gov (United States)

    Zeigler, John M.

    1992-01-01

    Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

  16. Dissolution chemistry and biocompatibility of single-crystalline silicon nanomembranes and associated materials for transient electronics.

    Science.gov (United States)

    Hwang, Suk-Won; Park, Gayoung; Edwards, Chris; Corbin, Elise A; Kang, Seung-Kyun; Cheng, Huanyu; Song, Jun-Kyul; Kim, Jae-Hwan; Yu, Sooyoun; Ng, Joanne; Lee, Jung Eun; Kim, Jiyoung; Yee, Cassian; Bhaduri, Basanta; Su, Yewang; Omennetto, Fiorenzo G; Huang, Yonggang; Bashir, Rashid; Goddard, Lynford; Popescu, Gabriel; Lee, Kyung-Mi; Rogers, John A

    2014-06-24

    Single-crystalline silicon nanomembranes (Si NMs) represent a critically important class of material for high-performance forms of electronics that are capable of complete, controlled dissolution when immersed in water and/or biofluids, sometimes referred to as a type of "transient" electronics. The results reported here include the kinetics of hydrolysis of Si NMs in biofluids and various aqueous solutions through a range of relevant pH values, ionic concentrations and temperatures, and dependence on dopant types and concentrations. In vitro and in vivo investigations of Si NMs and other transient electronic materials demonstrate biocompatibility and bioresorption, thereby suggesting potential for envisioned applications in active, biodegradable electronic implants.

  17. Degree of dissociation measured by FTIR absorption spectroscopy applied to VHF silane plasmas

    International Nuclear Information System (INIS)

    Sansonnens, L.; Howling, A.A.; Hollenstein, C.

    1997-10-01

    In situ Fourier transform infrared (FTIR) absorption spectroscopy has been used to determine the fractional depletion of silane in a radio-frequency (rf) glow discharge. The technique used a simple single pass arrangement and was implemented in a large area industrial reactor for deposition of amorphous silicon. Measurements were made on silane plasmas for a range of excitation frequencies. It was observed that at constant plasma power, the fractional depletion increased from 35% at 13.56 MHz to 70% at 70 MHz. With a simple model based on the density continuity equations in the gas phase, it was shown that this increase is due to a higher dissociation rate and is largely responsible for the observed increase in the deposition rate with the frequency. (author) 5 figs., 30 refs

  18. Composite materials and bodies including silicon carbide and titanium diboride and methods of forming same

    Science.gov (United States)

    Lillo, Thomas M.; Chu, Henry S.; Harrison, William M.; Bailey, Derek

    2013-01-22

    Methods of forming composite materials include coating particles of titanium dioxide with a substance including boron (e.g., boron carbide) and a substance including carbon, and reacting the titanium dioxide with the substance including boron and the substance including carbon to form titanium diboride. The methods may be used to form ceramic composite bodies and materials, such as, for example, a ceramic composite body or material including silicon carbide and titanium diboride. Such bodies and materials may be used as armor bodies and armor materials. Such methods may include forming a green body and sintering the green body to a desirable final density. Green bodies formed in accordance with such methods may include particles comprising titanium dioxide and a coating at least partially covering exterior surfaces thereof, the coating comprising a substance including boron (e.g., boron carbide) and a substance including carbon.

  19. Hardness of model dental composites - the effect of filler volume fraction and silanation.

    Science.gov (United States)

    McCabe, J F; Wassell, R W

    1999-05-01

    The relationship between structure and mechanical properties for dental composites has often proved difficult to determine due to the use of commercially available materials having a number of differences in composition i.e. different type of resin, different type of filler, etc. This makes a scientific study of any one variable such as filler content difficult if not impossible. In the current study it was the aim to test the hypothesis that hardness measurements of dental composites could be used to monitor the status of the resin-filler interface and to determine the efficacy of any particle silanation process. Ten model composites formulated from a single batch of resin and containing a common type of glass filler were formulated to contain varying amounts of filler. Some materials contained silanated filler, others contained unsilanated filler. Specimens were prepared and stored in water and hardness (Vickers') was determined at 24 h using loads of 50, 100, 200 and 300 g. Composites containing silanated fillers were significantly harder than materials containing unsilanated fillers. For unsilanated products hardness was independent of applied load and in this respect they behaved like homogeneous materials. For composites containing silanated fillers there was a marked increase in measured hardness as applied load was increased. This suggests that the hardness-load profile could be used to monitor the status of the resin-filler interface. Copyright 1999 Kluwer Academic Publishers

  20. Signals from fluorescent materials on the surface of silicon micro-strip sensors

    CERN Document Server

    Sperlich, Dennis; The ATLAS collaboration

    2017-01-01

    For the High-Luminosity Upgrade of the Large Hadron Collider at CERN, the ATLAS Inner Detector will be replaced with a new, all-silicon tracker. In order to minimise the amount of material in the detector, circuit boards with readout electronics will be glued on to the active area of the sensor. Several adhesives investigated to be used for the construction of detector modules were found to become fluorescent when exposed to UV light. These adhesives could become a light source in the high-radiation environment of the ATLAS detector. The effect of fluorescent material covering the sensor surface in a high- radiation environment has been studied for a silicon micro-strip sensor using a micro-focused X-ray beam. By pointing the beam both inside the sensor and parallel to the sensor surface, the sensor responses from direct hits and fluorescence can be compared with high precision. This contribution presents a setup to study the susceptibility of silicon strip sensors to light contamination from fluorescent mate...

  1. Nanostructured 2D cellular materials in silicon by sidewall transfer lithography NEMS

    Science.gov (United States)

    Syms, Richard R. A.; Liu, Dixi; Ahmad, Munir M.

    2017-07-01

    Sidewall transfer lithography (STL) is demonstrated as a method for parallel fabrication of 2D nanostructured cellular solids in single-crystal silicon. The linear mechanical properties of four lattices (perfect and defected diamond; singly and doubly periodic honeycomb) with low effective Young’s moduli and effective Poisson’s ratio ranging from positive to negative are modelled using analytic theory and the matrix stiffness method with an emphasis on boundary effects. The lattices are fabricated with a minimum feature size of 100 nm and an aspect ratio of 40:1 using single- and double-level STL and deep reactive ion etching of bonded silicon-on-insulator. Nanoelectromechanical systems (NEMS) containing cellular materials are used to demonstrate stretching, bending and brittle fracture. Predicted edge effects are observed, theoretical values of Poisson’s ratio are verified and failure patterns are described.

  2. Eighth Workshop on Crystalline Silicon Solar Cell Materials and Processes; Summary Discussion Sessions

    International Nuclear Information System (INIS)

    Sopori, B.; Swanson, D.; Sinton, R.; Stavola, M.; Tan, T.

    1998-01-01

    This report is a summary of the panel discussions included with the Eighth Workshop on Crystalline Silicon Solar Cell Materials and Processes. The theme of the workshop was ''Supporting the Transition to World Class Manufacturing.'' This workshop provided a forum for an informal exchange of information between researchers in the photovoltaic and nonphotovoltaic fields on various aspects of impurities and defects in silicon, their dynamics during device processing, and their application in defect engineering. This interaction helped establish a knowledge base that can be used for improving device-fabrication processes to enhance solar-cell performance and reduce cell costs. It also provided an excellent opportunity for researchers from industry and universities to recognize mutual needs for future joint research

  3. Minority carrier diffusion lengths and absorption coefficients in silicon sheet material

    Science.gov (United States)

    Dumas, K. A.; Swimm, R. T.

    1980-01-01

    Most of the methods which have been developed for the measurement of the minority carrier diffusion length of silicon wafers require that the material have either a Schottky or an ohmic contact. The surface photovoltage (SPV) technique is an exception. The SPV technique could, therefore, become a valuable diagnostic tool in connection with current efforts to develop low-cost processes for the production of solar cells. The technique depends on a knowledge of the optical absorption coefficient. The considered investigation is concerned with a reevaluation of the absorption coefficient as a function of silicon processing. A comparison of absorption coefficient values showed these values to be relatively consistent from sample to sample, and independent of the sample growth method.

  4. Effect of calcium/silicon ratio on retention of uranium (VI) in portland cement materials

    International Nuclear Information System (INIS)

    Tan Hongbin; Li Yuxiang

    2005-01-01

    Calcium silicate hydrate (CSH) materials of varied calcium to silicon (Ca/Si) ratios were prepared by hydrothermal synthesis at 80 degree C, with calcium oxide and micro-silicon employed. These products were determined to be of gel phase by XRD. Leaching tests with 1% hydrochloric acid indicated that more Uranium (VI) was detained by CSH with lower Ca/Si ratios. Alkali-activated slag cement (with a lower Ca/Si ratio) was found to have a stronger retention capacity than Portland cement (with a higher Ca/Si ratio), at 25 degree C in 102-days leaching tests with simulated solidified forms containing Uranium (VI). The accumulative leaching fraction of Uranium (VI) for Alkali-activated slag cement solidified forms is 17.6% lower than that for Portland cement. The corresponding difference of diffusion coefficients is 40.6%. This could be correlated with the difference of Ca/Si ratios between cements of two kinds. (authors)

  5. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Directory of Open Access Journals (Sweden)

    Lyndon Jones

    2012-01-01

    Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

  6. Evaluation of selected chemical processes for production of low-cost silicon phase 2. silicon material task, low-cost silicon solar array project

    Science.gov (United States)

    Blocher, J. M., Jr.; Browning, M. F.; Rose, E. E.; Thompson, W. B.; Schmitt, W. A.; Fippin, J. S.; Kidd, R. W.; Liu, C. Y.; Kerbler, P. S.; Ackley, W. R.

    1978-01-01

    Progress from October 1, 1977, through December 31, 1977, is reported in the design of the 50 MT/year experimental facility for the preparation of high purity silicon by the zinc vapor reduction of silicon tetrachloride in a fluidized bed of seed particles to form a free flowing granular product.

  7. Does 8-methacryloxyoctyl trimethoxy silane (8-MOTS) improve initial bond strength on lithium disilicate glass ceramic?

    Science.gov (United States)

    Maruo, Yukinori; Nishigawa, Goro; Yoshihara, Kumiko; Minagi, Shogo; Matsumoto, Takuya; Irie, Masao

    2017-03-01

    Dental ceramic surfaces are modified with silane coupling agents, such as γ-methacryloxypropyl trimethoxy silane (γ-MPTS), to improve bond strength. For bonding between lithium disilicate glass ceramic and resin cement, the objective was to investigate if 8-methacryloxyoctyl trimethoxy silane (8-MOTS) could yield a similar performance as the widely used γ-MPTS. One hundred and ten lithium disilicate glass ceramic specimens were randomly divided into 11 groups (n=10) according to pretreatment regime. All specimens were pretreated with a different solution composed of one or a combination of these agents: 10 or 20wt% silane coupling agent of γ-MPTS or 8-MOTS, followed by a hydrolysis solution of acetic acid or 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). Each pretreated surface was luted to a stainless steel rod of 3.6mm diameter and 2.0mm height with resin cement. Shear bond strength between ceramic and cement was measured after 24-h storage in 37°C distilled water. 8-MOTS produced the same bonding performance as γ-MPTS. Both silane coupling agents significantly increased the bond strength of resin cement, depending on their concentration. When activated by 10-MDP hydrolysis solution, 20wt% concentration produced the highest values (γ-MPTS: 24.9±5.1MPa; 8-MOTS: 24.6±7.4MPa). Hydrolysis with acetic acid produced lower bond strengths than with 10-MDP. Silane coupling pretreatment with 8-MOTS increased the initial bond strength between lithium disilicate glass ceramic and resin cement, rendering the same bonding effect as the conventional γ-MPTS. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Materials and fabrication sequences for water soluble silicon integrated circuits at the 90 nm node

    International Nuclear Information System (INIS)

    Yin, Lan; Harburg, Daniel V.; Rogers, John A.; Bozler, Carl; Omenetto, Fiorenzo

    2015-01-01

    Tungsten interconnects in silicon integrated circuits built at the 90 nm node with releasable configurations on silicon on insulator wafers serve as the basis for advanced forms of water-soluble electronics. These physically transient systems have potential uses in applications that range from temporary biomedical implants to zero-waste environmental sensors. Systematic experimental studies and modeling efforts reveal essential aspects of electrical performance in field effect transistors and complementary ring oscillators with as many as 499 stages. Accelerated tests reveal timescales for dissolution of the various constituent materials, including tungsten, silicon, and silicon dioxide. The results demonstrate that silicon complementary metal-oxide-semiconductor circuits formed with tungsten interconnects in foundry-compatible fabrication processes can serve as a path to high performance, mass-produced transient electronic systems

  9. Materials and fabrication sequences for water soluble silicon integrated circuits at the 90 nm node

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Lan; Harburg, Daniel V.; Rogers, John A., E-mail: jrogers@illinois.edu [Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 S Goodwin Ave., Urbana, Illinois 61801 (United States); Bozler, Carl [Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, Massachusetts 02420 (United States); Omenetto, Fiorenzo [Department of Biomedical Engineering, Department of Physics, Tufts University, 4 Colby St., Medford, Massachusetts 02155 (United States)

    2015-01-05

    Tungsten interconnects in silicon integrated circuits built at the 90 nm node with releasable configurations on silicon on insulator wafers serve as the basis for advanced forms of water-soluble electronics. These physically transient systems have potential uses in applications that range from temporary biomedical implants to zero-waste environmental sensors. Systematic experimental studies and modeling efforts reveal essential aspects of electrical performance in field effect transistors and complementary ring oscillators with as many as 499 stages. Accelerated tests reveal timescales for dissolution of the various constituent materials, including tungsten, silicon, and silicon dioxide. The results demonstrate that silicon complementary metal-oxide-semiconductor circuits formed with tungsten interconnects in foundry-compatible fabrication processes can serve as a path to high performance, mass-produced transient electronic systems.

  10. Spectroscopic diagnostics and modelling of silane microwave plasmas

    International Nuclear Information System (INIS)

    Fantz, U.

    1998-01-01

    Low-pressure silane plasmas (2-20 Pa) diluted with the noble gases helium and argon as well as hydrogen were generated by microwave excitation in order to determine plasma parameters and absolute particle number densities. Specific silane radicals (SiH, Si, H 2 , H) were measured by means of optical emission spectroscopy, whereas particle densities of silane, disilane and molecular hydrogen were measured with mass spectroscopy. Experimental results confirm model calculations, which were carried out to determine number densities of all silane radicals and of higher silanes as well as electron temperature. The electron temperature varies from 1.5 to 4 eV depending on pressure and gas mixture. The temperature of heavy particles is 450 K and the electron number density is 9x10 16 m -3 . The rotational temperatures of SiH are between room temperature and 2000 K due to increasing dissociative excitation. In the plasma the number density of silane is reduced, whereas the number density of molecular hydrogen is close to the silane density, which is fed in. Particle densities of SiH 3 , disilane and atomic hydrogen are in the range of a few per cent of the silane number density. At low pressure the SiH 2 density is similar to SiH 3 and decreases with increasing pressure due to heavy particle collisions with silane producing higher silanes. Particle densities of SiH and Si are only in the range of some 10 -3 of the silane density decreasing with increasing collisions of heavy particles with silane and molecular hydrogen. In mixtures with argon Penning reactions increase the silane dissociation. (author)

  11. Intensifying the Casimir force between two silicon substrates within three different layers of materials

    International Nuclear Information System (INIS)

    Seyedzahedi, A.; Moradian, A.; Setare, M.R.

    2016-01-01

    We investigate the Casimir force for a system composed of two thick slabs as substrates within three different homogeneous layers. We use the scattering approach along with the Matsubara formalism in order to calculate the Casimir force at finite temperature. First, we focus on constructing the reflection matrices and then we calculate the Casimir force for a water–lipid system. According to the conventional use of silicon as a substrate, we apply the formalism to calculate the Casimir force for layers of Au, VO 2 , mica, KCl and foam rubber on the thick slabs of silicon. Afterwards, introducing an increasing factor, we compare our results with Lifshitz force in the vacuum between two semispaces of silicon in order to illustrate the influence of the layers on intensifying the Casimir force. We also calculate the Casimir force between two slabs of the forementioned materials with finite thicknesses to indicate the substrate's role in increasing the obtained Casimir force. Our simple calculation is interesting since one can extend it along with the Rigorous Coupled Wave Analysis to systems containing inhomogeneous layers as good candidates for designing nanomechanical devices.

  12. Intensifying the Casimir force between two silicon substrates within three different layers of materials

    Energy Technology Data Exchange (ETDEWEB)

    Seyedzahedi, A. [Department of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Moradian, A., E-mail: a.moradian@uok.ac.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Setare, M.R., E-mail: rezakord@ipm.ir [Department of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2016-04-01

    We investigate the Casimir force for a system composed of two thick slabs as substrates within three different homogeneous layers. We use the scattering approach along with the Matsubara formalism in order to calculate the Casimir force at finite temperature. First, we focus on constructing the reflection matrices and then we calculate the Casimir force for a water–lipid system. According to the conventional use of silicon as a substrate, we apply the formalism to calculate the Casimir force for layers of Au, VO{sub 2}, mica, KCl and foam rubber on the thick slabs of silicon. Afterwards, introducing an increasing factor, we compare our results with Lifshitz force in the vacuum between two semispaces of silicon in order to illustrate the influence of the layers on intensifying the Casimir force. We also calculate the Casimir force between two slabs of the forementioned materials with finite thicknesses to indicate the substrate's role in increasing the obtained Casimir force. Our simple calculation is interesting since one can extend it along with the Rigorous Coupled Wave Analysis to systems containing inhomogeneous layers as good candidates for designing nanomechanical devices.

  13. Design and evaluation of carbon nanofiber and silicon materials for neural implant applications

    Science.gov (United States)

    McKenzie, Janice L.

    Reduction of glial scar tissue around central nervous system implants is necessary for improved efficacy in chronic applications. Design of materials that possess tunable properties inspired by native biological tissue and elucidation of pertinent cellular interactions with these materials was the motivation for this study. Since nanoscale carbon fibers possess the fundamental dimensional similarities to biological tissue and have attractive material properties needed for neural biomaterial implants, this present study explored cytocompatibility of these materials as well as modifications to traditionally used silicon. On silicon materials, results indicated that nanoscale surface features reduced astrocyte functions, and could be used to guide neurite extension from PC12 cells. Similarly, it was determined that astrocyte functions (key cells in glial scar tissue formation) were reduced on smaller diameter carbon fibers (125 nm or less) while PC12 neurite extension was enhanced on smaller diameter carbon fibers (100 nm or less). Further studies implicated laminin adsorption as a key mechanism in enhancing astrocyte adhesion to larger diameter fibers and at the same time encouraging neurite extension on smaller diameter fibers. Polycarbonate urethane (PCU) was then used as a matrix material for the smaller diameter carbon fibers (100 and 60 nm). These composites proved very versatile since electrical and mechanical properties as well as cell functions and directionality could be influenced by changing bulk and surface composition and features of these matrices. When these composites were modified to be smooth at the micronscale and only rough at the nanoscale, P19 cells actually submerged philopodia, extensions, or whole cells bodies beneath the PCU in order to interact with the carbon nanofibers. These carbon nanofiber composites that have been formulated are a promising material to coat neural probes and thereby enhance functionality at the tissue interface. This

  14. X-Ray Researches GF Siliconized Materials on Pyrocarbon Sheaf and on the Basis of Graphite of Mark EG-0

    International Nuclear Information System (INIS)

    Gurin, V.A.; Gurin, I.V.; Kovtun, G.P.; Malykhin, D.G.; Bukolov, A.N.

    2005-01-01

    A methodological addition to a quantitative analysis of binary phase structure of materials on measurements of X-ray lines intensities worked out conformably to research of siliconized graphitic materials. Distinctions in X-rays absorption factors of phase components at a various degree of phases mixture are taken into account. An apparatus of the probability theory is applied. A parameter of mixture degree of phases is submitted as a specific area size of interphase. Quantitative X-ray researches of a phase structure of siliconized materials are carried out on the basis of carbon fabrics and graphitic powders; both were sheafed by pyrocarbon. In examined samples structures C-SiC and SiC-Si were obtained. The correlation of the phase structure of materials with the apparent density of the initial carbon basis is seen. The opportunity of a practical obtaining of materials with the host degree of their siliconizing is confirmed

  15. Novel scalable silicone elastomer and poly(2-hydroxyethyl methacrylate) (PHEMA) composite materials for tissue engineering and drug delivery applications

    DEFF Research Database (Denmark)

    Mohanty, Soumyaranjan; Hemmingsen, Mette; Wojcik, Magdalena

    2013-01-01

    material with increased hydrophilicity in regard to virgin silicone elastomer, making it suitable as a scaffold for tissue engineering and with the concomitant possibility for delivering drug from the scaffold to the tissue. Interpenetrating polymer networks (IPNs) of silicone elastomer and PHEMA......In recent years hydrogels have received increasing attention as potential materials for applications in regenerative medicine. They can be used for scaffold materials providing structural integrity to tissue constructs, for controlled delivery of drugs and proteins to cell and tissues......, and for support materials in tissue growth. However, the real challenge is to obtain sufficiently good mechanical properties of the hydrogel. The present study shows the combination of two normally non-compatible materials, silicone elastomer and poly(2-hydroxyethyl methacrylate) (PHEMA), into a novel composite...

  16. Comparison of pad detectors produced on different silicon materials after irradiation with neutrons, protons and pions

    International Nuclear Information System (INIS)

    Kramberger, G.; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

    2010-01-01

    A set of 44 pad detectors produced on p- and n-type MCz and Fz wafers was irradiated with 23 GeV protons, 200 MeV pions and reactor neutrons up to the equivalent fluences of Φ eq =3x10 15 cm -2 . The evolution of the full depletion voltage and the leakage current were monitored during short- and long-term annealing. At selected representative annealing steps, charge collection measurements were performed for all samples with LHC speed electronics. Measurements of full depletion voltage, leakage current and charge collection efficiency were compared for different irradiation particles and silicon materials.

  17. Comparison of pad detectors produced on different silicon materials after irradiation with neutrons, protons and pions

    Energy Technology Data Exchange (ETDEWEB)

    Kramberger, G., E-mail: Gregor.Kramberger@ijs.s [Jozef Stefan Institute and Department of Physics, University of Ljubljana, SI-1000 Ljubljana (Slovenia); Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M. [Jozef Stefan Institute and Department of Physics, University of Ljubljana, SI-1000 Ljubljana (Slovenia)

    2010-01-01

    A set of 44 pad detectors produced on p- and n-type MCz and Fz wafers was irradiated with 23 GeV protons, 200 MeV pions and reactor neutrons up to the equivalent fluences of PHI{sub eq}=3x10{sup 15}cm{sup -2}. The evolution of the full depletion voltage and the leakage current were monitored during short- and long-term annealing. At selected representative annealing steps, charge collection measurements were performed for all samples with LHC speed electronics. Measurements of full depletion voltage, leakage current and charge collection efficiency were compared for different irradiation particles and silicon materials.

  18. Current and future priorities for mass and material in silicon PV module recycling

    Energy Technology Data Exchange (ETDEWEB)

    Olson, C.L.; Geerligs, L.J.; Goris, M.J.A.A.; Bennett, I.J. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Clyncke, J. [PV CYCLE, Rue Montoyer 23, 1000 Brussels (Belgium)

    2013-10-15

    A full description of the state-of-the-art PV recycling methods and their rationale is presented, which discusses the quality of the recycled materials and the fate of the substances which end up in the landfill. The aim is to flag the PV module components currently not recycled, which may have a priority in terms of their embedded energy, chemical nature or scarcity, for the next evolution of recycling. The sustainability of different recycling options, emerging in the literature on electronic waste recycling, and the possible improvement of the environmental footprint of silicon PV modules, will be discussed.

  19. Determination of silicon in biological and botanical reference materials by epithermal INAA and Compton suppression

    International Nuclear Information System (INIS)

    Landsberger, S.; Peshev, S.; Becker, D.A.

    1994-01-01

    Silicon determination in sixteen botanical and biological standard reference materials is described using the 29 Si(n, p) 29 Al reaction through instrumental epithermal neutron activation analysis and Compton suppression gamma-ray spectroscopy. By simultaneous utilization of both cadmium and boron epithermal filters along with anticoincidence gamma-counting, detection limits as low as 12 ppm were obtained for certain matrices, much lower than previously reported values for this type of analysis. The method is applicable to many botanical and biological matrices and is attractive with its interference free, purely instrumental nature, compared with methods using the 28 Si(n, p) 28 Al reaction or chemical separation techniques. ((orig.))

  20. Hot Ta filament resistance in-situ monitoring under silane containing atmosphere

    International Nuclear Information System (INIS)

    Grunsky, D.; Schroeder, B.

    2008-01-01

    Monitoring of the electrical resistance of the Ta catalyst during the hot wire chemical vapor deposition (HWCVD) of thin silicon films gives information about filament condition. Using Ta filaments for silane decomposition not only the well known strong changes at the cold ends, but also changes of the central part of the filament were observed. Three different phenomena can be distinguished: silicide (stoichiometric Ta X Si Y alloys) growth on the filament surfaces, diffusion of Si into the Ta filament and thick silicon deposits (TSD) formation on the filament surface. The formation of different tantalum silicides on the surface as well as the in-diffusion of silicon increase the filament resistance, while the TSDs form additional electrical current channels and that result in a decrease of the filament resistance. Thus, the filament resistance behaviour during ageing is the result of the competition between these two processes

  1. Effect of Projectile Materials on Foreign Object Damage of a Gas-Turbine Grade Silicon Nitride

    Science.gov (United States)

    Choi, Sung R.; Racz, Zsolt; Bhatt, Ramakrishna T.; Brewer, David N.; Gyekenyesi, John P.

    2005-01-01

    Foreign object damage (FOD) behavior of AS800 silicon nitride was determined using four different projectile materials at ambient temperature. The target test specimens rigidly supported were impacted at their centers by spherical projectiles with a diameter of 1.59 mm. Four different types of projectiles were used including hardened steel balls, annealed steel balls, silicon nitride balls, and brass balls. Post-impact strength of each target specimen impacted was determined as a function of impact velocity to better understand the severity of local impact damage. The critical impact velocity where target specimens fail upon impact was highest with brass balls, lowest with ceramic ball, and intermediate with annealed and hardened steel balls. Degree of strength degradation upon impact followed the same order as in the critical impact velocity with respect to projectile materials. For steel balls, hardened projectiles yielded more significant impact damage than annealed counterparts. The most important material parameter affecting FOD was identified as hardness of projectiles and was correlated in terms of critical impact velocity, impact deformation, and impact load.

  2. Characterization of silicon sensor materials and designs for the CMS Tracker Upgrade

    CERN Document Server

    Dierlamm, Alexander Hermann

    2012-01-01

    During the high luminosity phase of the LHC (HL-LHC, starting around 2020) the inner tracking system of CMS will be exposed to harsher conditions than the current system was designed for. Therefore a new tracker is planned to cope with higher radiation levels and higher occupancies. Within the strip sensor developments of CMS a comparative survey of silicon materials and technologies is being performed in order to identify the baseline material for the future tracker. Hence, a variety of materials (float-zone, magnetic Czochralski and epitaxially grown silicon with thicknesses from 50$\\mu$m to 320$\\mu$m as p- and n-type) has been processed at one company (Hamamatsu Photonics K.K.), irradiated (proton, neutron and mixed irradiations up to 1.5e15n$_{eq}$/cm$^2$ and beyond) and tested under identical conditions. The wafer layout includes a variety of devices to investigate different aspects of sensor properties like simple diodes, test-structures, small strip sensors and a strip sensor array with varying strip p...

  3. Corrosion protection of galvanized steels by silane-based treatments

    Science.gov (United States)

    Yuan, Wei

    The possibility of using silane coupling agents as replacements for chromate treatments was investigated on galvanized steel substrates. In order to understand the influence of deposition parameters on silane film formation, pure zinc substrates were first used as a model for galvanized steel to study the interaction between silane coupling agents and zinc surfaces. The silane films formed on pure zinc substrates from aqueous solutions were characterized by ellipsometry, contact angle measurements, reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscopy. The deposition parameters studied include solution concentration, solution dipping time and pH value of the applied solution. It appears that silane film formation involved a true equilibrium of hydrolysis and condensation reactions in aqueous solutions. It has been found that the silane film thickness obtained depends primarily on the solution concentration and is almost independent of the solution dipping time. The molecular orientation of applied silane films is determined by the pH value of applied silane solutions and the isoelectric point of metal substrates. The deposition window in terms of pH value for zinc substrates is between 6.0 and 9.0. The total surface energy of the silane-coated pure zinc substrates decreases with film aging time, the decrease rate, however, is determined by the nature of silane coupling agents. Selected silane coupling agents were applied as prepaint or passivation treatments onto galvanized steel substrates. The corrosion protection provided by these silane-based treatments were evaluated by salt spray test, cyclic corrosion test, electrochemical impedance spectroscopy, and stack test. The results showed that silane coupling agents can possibly be used to replace chromates for corrosion control of galvanized steel substrates. Silane coatings provided by these silane treatments serve mainly as physical barriers. Factors that

  4. Thermally Induced Silane Dehydrocoupling on Silicon Nanostructures (International ed.)

    Science.gov (United States)

    2016-07-29

    Chemistry and Biochemistry University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093 (USA) E-mail: msailor@ucsd.edu Dr. Y. Pan, Dr. B...M.Wayner, D. J. Lockwood, J. Electrochem. Soc. 2002, 149, H59 –H63; c) S. Ciampi, J. B. Harper , J. J. Gooding, Chem. Soc. Rev. 2010, 39, 2158 – 2183; d

  5. Recent Progress in Synthesis and Application of Low-Dimensional Silicon Based Anode Material for Lithium Ion Battery

    Directory of Open Access Journals (Sweden)

    Yuandong Sun

    2017-01-01

    Full Text Available Silicon is regarded as the next generation anode material for LIBs with its ultra-high theoretical capacity and abundance. Nevertheless, the severe capacity degradation resulting from the huge volume change and accumulative solid-electrolyte interphase (SEI formation hinders the silicon based anode material for further practical applications. Hence, a variety of methods have been applied to enhance electrochemical performances in terms of the electrochemical stability and rate performance of the silicon anodes such as designing nanostructured Si, combining with carbonaceous material, exploring multifunctional polymer binders, and developing artificial SEI layers. Silicon anodes with low-dimensional structures (0D, 1D, and 2D, compared with bulky silicon anodes, are strongly believed to have several advanced characteristics including larger surface area, fast electron transfer, and shortened lithium diffusion pathway as well as better accommodation with volume changes, which leads to improved electrochemical behaviors. In this review, recent progress of silicon anode synthesis methodologies generating low-dimensional structures for lithium ion batteries (LIBs applications is listed and discussed.

  6. 3D printing PLA and silicone elastomer structures with sugar solution support material

    Science.gov (United States)

    Hamidi, Armita; Jain, Shrenik; Tadesse, Yonas

    2017-04-01

    3D printing technology has been used for rapid prototyping since 1980's and is still developing in a way that can be used for customized products with complex design and miniature features. Among all the available 3D printing techniques, Fused Deposition Modeling (FDM) is one of the most widely used technologies because of its capability to build different structures by employing various materials. However, complexity of parts made by FDM is greatly limited by restriction of using support materials. Support materials are often used in FDM for several complex geometries such as fully suspended shapes, overhanging surfaces and hollow features. This paper describes an approach to 3D print a structure using silicone elastomer and polylactide fiber (PLA) by employing a novel support material that is soluble in water. This support material is melted sugar which can easily be prepared at a low cost. Sugar is a carbohydrate, which is found naturally in plants such as sugarcane and sugar beets; therefore, it is completely organic and eco-friendly. As another advantage, the time for removing this material from the part is considerably less than other commercially available support materials and it can be removed easily by warm water without leaving any trace. Experiments were done using an inexpensive desktop 3D printer to fabricate complex structures for use in soft robots. The results envision that further development of this system would contribute to a method of fabrication of complex parts with lower cost yet high quality.

  7. Energy Conversion Properties of ZnSiP2, a Lattice-Matched Material for Silicon-Based Tandem Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aaron D.; Warren, Emily L.; Gorai, Prashun; Borup, Kasper A.; Krishna, Lakshmi; Kuciauskas, Darius; Dippo, Patricia C.; Ortiz, Brenden R.; Stradins, Paul; Stevanovic, Vladan; Toberer, Eric S.; Tamboli, Adele C.

    2016-11-21

    ZnSiP2 demonstrates promising potential as an optically active material on silicon. There has been a longstanding need for wide band gap materials that can be integrated with Si for tandem photovoltaics and other optoelectronic applications. ZnSiP2 is an inexpensive, earth abundant, wide band gap material that is stable and lattice matched with silicon. This conference proceeding summarizes our PV-relevant work on bulk single crystal ZnSiP2, highlighting the key findings and laying the ground work for integration into Si-based tandem devices.

  8. Determination of a silane intermolecular force field potential model from an ab initio calculation

    International Nuclear Information System (INIS)

    Li, Arvin Huang-Te; Chao, Sheng D.; Chang, Chien-Cheng

    2010-01-01

    Intermolecular interaction potentials of the silane dimer in 12 orientations have been calculated by using the Hartree-Fock (HF) self-consistent theory and the second-order Moeller-Plesset (MP2) perturbation theory. We employed basis sets from Pople's medium-size basis sets [up to 6-311++G(3df, 3pd)] and Dunning's correlation consistent basis sets (up to the triply augmented correlation-consistent polarized valence quadruple-zeta basis set). We found that the minimum energy orientations were the G and H conformers. We have suggested that the Si-H attractions, the central silicon atom size, and electronegativity play essential roles in weakly binding of a silane dimer. The calculated MP2 potential data were employed to parametrize a five-site force field for molecular simulations. The Si-Si, Si-H, and H-H interaction parameters in a pairwise-additive, site-site potential model for silane molecules were regressed from the ab initio energies.

  9. Negative ion mass spectra and particulate formation in rf silane plasma deposition experiments

    International Nuclear Information System (INIS)

    Howling, A.A.; Dorier, J.L.; Hollenstein, C.

    1992-09-01

    Negative ions have been clearly identified in silane rf plasmas used for the deposition of amorphous silicon. Mass spectra were measured for monosilicon up to pentasilicon negative ion radical groups in power-modulated plasmas by means of a mass spectrometer mounted just outside the glow region. Negative ions were only observed over a limited range of power modulation frequency which corresponds to particle-free conditions. The importance of negative ions regarding particulate formation is demonstrated and commented upon. (author) 3 figs., 19 refs

  10. Charge transfer processes in hybrid solar cells composed of amorphous silicon and organic materials

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Sebastian; Neher, Dieter [Universitaet Potsdam, Inst. Physik u. Astronomie, Karl-Liebknecht-Strasse 24/25, 14467 Potsdam-Golm (Germany); Schulze, Tim; Korte, Lars [Helmholtz Zentrum Berlin, Inst. fuer Silizium Photovoltaik, Kekulestrasse 5, 12489 Berlin (Germany)

    2011-07-01

    The efficiency of hybrid solar cells composed of organic materials and amorphous hydrogenated silicon (a-Si:H) strongly depends upon the efficiency of charge transfer processes at the inorganic-organic interface. We investigated the performance of devices comprising an ITO/a-Si:H(n-type)/a-Si:H(intrinsic)/organic/metal multilayer structure and using two different organic components: zinc phthalocyanine (ZnPc) and poly(3-hexylthiophene) (P3HT). The results show higher power conversion- and quantum efficiencies for the P3HT based cells, compared to ZnPc. This can be explained by larger energy-level offset at the interface between the organic layer and a-Si:H, which facilitates hole transfer from occupied states in the valence band tail to the HOMO of the organic material and additionally promotes exciton splitting. The performance of the a-Si:H/P3HT cells can be further improved by treatment of the amorphous silicon surface with hydrofluoric acid (HF) and p-type doping of P3HT with F4TCNQ. The improved cells reached maximum power conversion efficiencies of 1%.

  11. Signals from fluorescent materials on the surface of silicon micro-strip sensors

    CERN Document Server

    Sperlich, Dennis; The ATLAS collaboration

    2018-01-01

    For the High-Luminosity Upgrade of the Large Hadron Collider at CERN, the ATLAS Inner Detector will be replaced with a new, all-silicon tracker (ITk). In order to minimise the amount of material in the ITk, circuit boards with readout electronics will be glued onto the active area of the sensor. Several adhesives, investigated to be used for the construction of detector modules, were found to become fluorescent when exposed to UV light. These adhesives could become a light source in the high-radiation environment of the ATLAS detector. The effect of fluorescent material covering the sensor surface in a high-radiation environment has been studied for a silicon micro-strip sensor using a micro-focused X-ray beam. By positioning the beam parallel to the sensor surfave and pointing it both inside the sensor and above the sensor surface inside the deposited glue, the sensor responses from direct hits and fluorescence can be compared with high precision. This contribution presents a setup to study the susceptibilit...

  12. Irradiation study of different silicon materials for the CMS tracker upgrade

    International Nuclear Information System (INIS)

    Erfle, Joachim

    2014-05-01

    Around 2022, an upgrade of the LHC collider complex is planned to significantly increase the luminosity (the High Luminosity LHC, HL-LHC). This means that the experiments have to cope with a higher number of collisions per bunch crossing and survive in a radiation environment much harsher than that at the present LHC. Especially the tracking detectors have to be improved for the HL-LHC. The increased number of tracks requires an increase of the number of readout channels while the higher radiation makes new sensor materials necessary. Within CMS, a measurement campaign was initiated to study the performance of different silicon materials in a corresponding radiation environment. To simulate the expected radiation the samples were irradiated with neutrons and with protons with two different energies. Radiation damage can be divided in two categories. First, ionizing energy loss in the surface isolation layers of the sensor leads to a change of the concentration of charged states in the sensor surface and therefore alters the distribution of the electrical fields in the sensor. Second, non-ionizing energy loss in the bulk of the sensor material leads to a variety of defects in the silicon lattice. Electrically active defects can influence the material properties. The three properties under investigation are the reverse current, the full depletion voltage and the charge collection. While the reverse current and full depletion voltage influence the power dissipation and the noise of the detector, the charge collection directly influences the measurement. The material properties were studied using pad and strip sensor. The structures were electrically characterized before and after irradiation with different fluences of neutrons and protons, corresponding to the expected fluences at different radii of the outer tracker after 3000 fb -1 . The charge collection measurements were mainly performed using the ALiBaVa readout system and the charge was induced with

  13. Use of Silicon Carbide as Beam Intercepting Device Material: Tests, Issues and Numerical Simulations

    CERN Document Server

    Delonca, M; Gil Costa, M; Vacca, A

    2014-01-01

    Silicon Carbide (SiC) stands as one of the most promising ceramic material with respect to its thermal shock resistance and mechanical strengths. It has hence been considered as candidate material for the development of higher performance beam intercepting devices at CERN. Its brazing with a metal counterpart has been tested and characterized by means of microstructural and ultrasound techniques. Despite the positive results, its use has to be evaluated with care, due to the strong evidence in literature of large and permanent volumetric expansion, called swelling, under the effect of neutron and ion irradiation. This may cause premature and sudden failure, and can be mitigated to some extent by operating at high temperature. For this reason limited information is available for irradiation below 100°C, which is the typical temperature of interest for beam intercepting devices like dumps or collimators. This paper describes the brazing campaign carried out at CERN, the results, and the theoretical and numeric...

  14. Contactless Spectral-dependent Charge Carrier Lifetime Measurements in Silicon Photovoltaic Materials

    Science.gov (United States)

    Roller, John; Hamadani, Behrang; Dagenais, Mario

    Charge carrier lifetime measurements in bulk or unfinished photovoltaic (PV) materials allow for a more accurate estimate of power conversion efficiency in completed solar cells. In this work, carrier lifetimes in PV-grade silicon wafers are obtained by way of quasi-steady state photoconductance measurements. These measurements use a contactless RF system coupled with varying narrow spectrum input LEDs, ranging in wavelength from 460 nm to 1030 nm. Spectral dependent lifetime measurements allow for determination of bulk and surface properties of the material, including the intrinsic bulk lifetime and the surface recombination velocity. The effective lifetimes are fit to an analytical physics-based model to determine the desired parameters. Passivated and non-passivated samples are both studied and are shown to have good agreement with the theoretical model.

  15. Double-shelled silicon anode nanocomposite materials: A facile approach for stabilizing electrochemical performance via interface construction

    Science.gov (United States)

    Du, Lulu; Wen, Zhongsheng; Wang, Guanqin; Yang, Yan-E.

    2018-04-01

    The rapid capacity fading induced by volumetric changes is the main issue that hinders the widespread application of silicon anode materials. Thus, double-shelled silicon composite materials where lithium silicate was located between an Nb2O5 coating layer and a silicon active core were configured to overcome the chemical compatibility issues related to silicon and oxides. The proposed composites were prepared via a facile co-precipitation method combined with calcination. Transmission electron microscopy and X-ray photoelectron spectroscopy analysis demonstrated that a transition layer of lithium silicate was constructed successfully, which effectively hindered the thermal inter-diffusion between the silicon and oxide coating layers during heat treatment. The electrochemical performance of the double-shelled silicon composites was enhanced dramatically with a retained specific capacity of 1030 mAh g-1 after 200 cycles at a current density of 200 mA g-1 compared with 598 mAh g-1 for a core-shell Si@Nb2O5 composite that lacked the interface. The lithium silicate transition layer was shown to play an important role in maintaining the high electrochemical stability.

  16. Rolling-element fatigue life of silicon nitride balls. [as compared to that of steel, ceramic, and cermet materials

    Science.gov (United States)

    Parker, R. J.; Zaretsky, E. V.

    1974-01-01

    The five-ball fatigue tester was used to evaluate silicon nitride as a rolling-element bearing material. Results indicate that hot-pressed silicon nitride running against steel may be expected to yield fatigue lives comparable to or greater than those of bearing quality steel running against steel at stress levels typical rolling-element bearing application. The fatigue life of hot-pressed silicon nitride is considerably greater than that of any ceramic or cermet tested. Computer analysis indicates that there is no improvement in the lives of 120-mm-bore angular--contact ball bearings of the same geometry operating at DN values from 2 to 4 million where hot-pressed silicon nitride balls are used in place of steel balls.

  17. Topological investigation of electronic silicon nanoparticulate aggregates using ultra-small-angle X-ray scattering

    CSIR Research Space (South Africa)

    Jonah, EO

    2012-10-01

    Full Text Available The network topology of two types of silicon nanoparticles, produced by high energy milling and pyrolysis of silane, in layers deposited from inks on permeable and impermeable substrates has been quantitatively characterized using ultra-small-angle...

  18. Enhancement of mechanical strength of TiO2/high-density polyethylene composites for bone repair with silane-coupling treatment

    International Nuclear Information System (INIS)

    Hashimoto, Masami; Takadama, Hiroaki; Mizuno, Mineo; Kokubo, Tadashi

    2006-01-01

    Mechanical properties of composites made up of high-density polyethylene (HDPE) and silanated TiO 2 particles for use as a bone-repairing material were investigated in comparison with those of the composites of HDPE with unsilanized TiO 2 particles. The interfacial morphology and interaction between silanated TiO 2 and HDPE were analyzed by means of Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The absorption in spectral bands related to the carboxyl bond in the silane-coupling agent, the vinyl group in the HDPE, and the formation of the ether bond was studied in order to assess the influence of the silane-coupling agent. The SEM micrograph showed that the 'bridging effect' between HDPE and TiO 2 was brought about by the silane-coupling agent. The use of the silane-coupling agent and the increase of the hot-pressing pressure for shaping the composites facilitated the penetration of polymer into cavities between individual TiO 2 particles, which increased the density of the composite. Therefore, mechanical properties such as bending yield strength and Young's modulus increased from 49 MPa and 7.5 GPa to 65 MPa and 10 GPa, respectively, after the silane-coupling treatment and increase in the hot-pressing pressure

  19. The influence of silane evaporation procedures on microtensile bond strength between a dental ceramic and a resin cement

    Directory of Open Access Journals (Sweden)

    Pereira Carolina

    2010-01-01

    Full Text Available Aim: To assess the influence of silane evaporation procedures on bond strength between a dental ceramic and a chemically activated resin cement. Materials and Methods: Eighteen blocks (6 mm Χ 14 mm Χ 14 mm of ceramic IPS Empress 2 were cemented (C and B to composite resin (InTen-S blocks using a chemical adhesive system (Lok. Six groups were analyzed, each with three blocks divided according to ceramic surface treatment: two control groups (no treatment, NT; 10% hydrofluoric acid plus silane Monobond-S dried at room temperature, HFS; the other four groups comprised different evaporation patterns (silane rinsed and dried at room temperature, SRT; silane rinsed in boiling water and dried as before, SBRT; silane rinsed with boiling water and heat dried at 50°C, SBH; silane dried at 50 ± 5°C, rinsed in boiling water and dried at room temperature, SHBRT. The cemented blocks were sectioned to obtain specimens for microtensile test 7 days after cementation and were stored in water for 30 days prior to testing. Fracture patterns were analyzed by optical and scanning electron microscopy. Statistics and Results: All blocks of NT debonded during sectioning. One way ANOVA tests showed higher bond strengths for HFS than for the other groups. SBRT and SBH were statistically similar, with higher bond strengths than SRT and SHBRT. Failures were 100% adhesive in SRT and SHBRT. Cohesive failures within the "adhesive zone" were detected in HFS (30%, SBRT (24% and SBH (40%. Conclusion: Silane treatment enhanced bond strength in all conditions evaluated, showing best results with HF etching.

  20. Penis augmentation by application of silicone material: complications and surgical treatment.

    Science.gov (United States)

    Sukop, A; Heracek, J; Mestak, O; Borský, J; Bayer, J; Schwarzmannová, K

    2013-01-01

    Complications resulting from enlargement of the penis by applications of unknown types of silicone and mineral oils are well described. Surgical removal of the tissue altered by inflammation leads to the development of defects of various sizes, often circular from the glans penis to the scrotum. The options of subsequent surgical treatment described in literature are not very extensive. Most defects are managed with skin grafting, rarely V-Y advancement or bilateral scrotal flaps. We present a 36-year-old patient after application of unknown silicone material into the penis for cosmetic enlargement. After the application developed severe inflammation with ulceration and necrosis around the penis. Conservative treatment was not effective, therefore, the infiltrated skin with subcutaneous tissue of the entire penis was surgically removed. The resulting defect was covered by implantation of the penis under the skin of the scrotum. There were no complications in the postoperative course, pain that was present before the surgery immediately subsided. Skin suture healed completely within 14 days. Three months after the surgery the patient returned to normal sexual life. Implantation of the penis under the skin of the scrotum is a fast, safe and effective method that can treat most of the circular skin defects of the penis. Scrotal skin is thin, soft, elastic and creates abundant and good cover around the entire penis.

  1. Silane decorated metallic nanorods for hydrophobic applications

    International Nuclear Information System (INIS)

    Kannarpady, Ganesh K.; Sharma, Rajesh; Liu Bo; Trigwell, Steve; Ryerson, Charles; Biris, Alexandru S.

    2010-01-01

    A novel technique to modify a metallic surface for anti-icing applications is presented. An oblique angle deposition (OAD) technique has been used to fabricate metallic nanorods of Aluminum and Tungsten on a glass substrate. A conformal coating of a silane has been applied using a molecular vapor deposition technique. The resulting surface has shown a static contact angle of 134 deg. with the water droplet. SEM, AFM and XPS have been used to study the surface modification. This is a highly promising approach for anti-icing applications due to its scalability at a very low cost.

  2. Aluminum and silicon based phase change materials for high capacity thermal energy storage

    International Nuclear Information System (INIS)

    Wang, Zhengyun; Wang, Hui; Li, Xiaobo; Wang, Dezhi; Zhang, Qinyong; Chen, Gang; Ren, Zhifeng

    2015-01-01

    Six compositions of aluminum (Al) and silicon (Si) based materials: 87.8Al-12.2Si, 80Al–20Si, 70Al–30Si, 60Al–40Si, 45Al–40Si–15Fe, and 17Al–53Si–30Ni (atomic ratio), were investigated for potentially high thermal energy storage (TES) application from medium to high temperatures (550–1200 °C) through solid–liquid phase change. Thermal properties such as melting point, latent heat, specific heat, thermal diffusivity and thermal conductivity were investigated by differential scanning calorimetry and laser flash apparatus. The results reveal that the thermal storage capacity of the Al–Si materials increases with increasing Si concentration. The melting point and latent heat of 45Al–40Si–15Fe and 17Al–53Si–30Ni are ∼869 °C and ∼562 J g −1 , and ∼1079 °C and ∼960 J g −1 , respectively. The measured thermal conductivity of Al–Si binary materials depend on Si concentration and is higher than 80 W m −1  K −1 from room temperature to 500 °C, which is almost two orders of magnitude higher than those of salts that are commonly used phase change material for thermal energy storage. - Highlights: • Six kinds of materials were investigated for thermal energy storage (550–1200 °C). • Partial melting of Al–Si materials show progressively changing temperatures. • Studied materials can be used in three different working temperature ranges. • Materials are potentially good candidates for thermal energy storage applications.

  3. Low-temperature synthesis of homogeneous nanocrystalline cubic silicon carbide films

    International Nuclear Information System (INIS)

    Cheng Qijin; Xu, S.

    2007-01-01

    Silicon carbide films are fabricated by inductively coupled plasma chemical vapor deposition from feedstock gases silane and methane heavily diluted with hydrogen at a low substrate temperature of 300 deg. C. Fourier transform infrared absorption spectroscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy analyses show that homogeneous nanocrystalline cubic silicon carbide (3C-SiC) films can be synthesized at an appropriate silane fraction X[100%xsilane flow(SCCM)/silane+methane flow(SCCM)] in the gas mixture. The achievement of homogeneous nanocrystalline 3C-SiC films at a low substrate temperature of 300 deg. C is a synergy of a low deposition pressure (22 mTorr), high inductive rf power (2000 W), heavy dilution of feedstock gases silane and methane with hydrogen, and appropriate silane fractions X (X≤33%) in the gas mixture employed in our experiments

  4. Extraction of Kinetic Parameters for the Chemical Vapor Deposition of Polycrystalline Silicon at Medium and Low Pressures

    NARCIS (Netherlands)

    Holleman, J.; Verweij, J.F.; Verweij, Jan F.

    1993-01-01

    The deposition of silicon (Si) from silane (SiH4) was studied in the silane pressure range from 0.5 to 100 Pa (0.005 to1 mbar) and total pressure range from 10 to 1000 Pa using N2 or He as carrier gases. The two reaction paths, namely,heterogeneous and homogeneous decomposition could be separated by

  5. Effects of Non-equilibrium Solidification on the Material Properties of Brick Silicon for Photovoltaics

    Science.gov (United States)

    Regnault, W. F.; Yoo, K. C.; Soltani, P. K.; Johnson, S. M.

    1984-01-01

    Silicon ingot growth technologies like the Ubiquitous Crystallization Process (UCP) are solidified within a shaping crucible. The rate at which heat can be lost from this crucible minus the rate at which heat is input from an external source determines the rate at which crystallization will occur. Occasionally, when the process parameters for solidification are exceeded, the normally large multi-centimeter grain size material assocated with the UCP will break down into regions containing extremely small, millimeter or less, grain size material. Accompanying this breakdown in grain growth is the development of so called sinuous grain boundaries. The breakdown in grain growth which results in this type of small grain structure with sinuous boundaries is usually associated with the rapid crystallization that would accompany a system failure. This suggests that there are limits to the growth velocity that one can obtain and still expect to produce material that would possess good photovoltaic properties. It is the purpose to determine the causes behind the breakdown of this material and what parameters will determine the best rates of solidification.

  6. Ninth workshop on crystalline silicon solar cell materials and processes: Summary discussion sessions

    International Nuclear Information System (INIS)

    Sopori, B.; Tan, T.; Swanson, D.; Rosenblum, M.; Sinton, R.

    1999-01-01

    This report is a summary of the panel discussions included with the Ninth Workshop on Crystalline Silicon Solar Cell Materials and Processes. The theme for the workshop was ''R and D Challenges and Opportunities in Si Photovoltaics''. This theme was chosen because it appropriately reflects a host of challenges that the growing production of Si photovoltaics will be facing in the new millennium. The anticipated challenges will arise in developing strategies for cost reduction, increased production, higher throughput per manufacturing line, new sources of low-cost Si, and the introduction of new manufacturing processes for cell production. At the same time, technologies based on CdTe and CIS will come on line posing new competition. With these challenges come new opportunities for Si PV to wean itself from the microelectronics industry, to embark on a more aggressive program in thin-film Si solar cells, and to try new approaches to process monitoring

  7. Terahertz optical-Hall effect for multiple valley band materials: n-type silicon

    International Nuclear Information System (INIS)

    Kuehne, P.; Hofmann, T.; Herzinger, C.M.; Schubert, M.

    2011-01-01

    The optical-Hall effect comprises generalized ellipsometry at long wavelengths on samples with free-charge carriers placed within external magnetic fields. Measurement of the anisotropic magneto-optic response allows for the determination of the free-charge carrier properties including spatial anisotropy. In this work we employ the optical-Hall effect at terahertz frequencies for analysis of free-charge carrier properties in multiple valley band materials, for which the optical free-charge carrier contributions originate from multiple Brillouin-zone conduction or valence band minima or maxima, respectively. We investigate exemplarily the room temperature optical-Hall effect in low phosphorous-doped n-type silicon where free electrons are located in six equivalent conduction-band minima near the X-point. We simultaneously determine their free-charge carrier concentration, mobility, and longitudinal and transverse effective mass parameters.

  8. Single Photon Counting UV Solar-Blind Detectors Using Silicon and III-Nitride Materials

    Science.gov (United States)

    Nikzad, Shouleh; Hoenk, Michael; Jewell, April D.; Hennessy, John J.; Carver, Alexander G.; Jones, Todd J.; Goodsall, Timothy M.; Hamden, Erika T.; Suvarna, Puneet; Bulmer, J.; Shahedipour-Sandvik, F.; Charbon, Edoardo; Padmanabhan, Preethi; Hancock, Bruce; Bell, L. Douglas

    2016-01-01

    Ultraviolet (UV) studies in astronomy, cosmology, planetary studies, biological and medical applications often require precision detection of faint objects and in many cases require photon-counting detection. We present an overview of two approaches for achieving photon counting in the UV. The first approach involves UV enhancement of photon-counting silicon detectors, including electron multiplying charge-coupled devices and avalanche photodiodes. The approach used here employs molecular beam epitaxy for delta doping and superlattice doping for surface passivation and high UV quantum efficiency. Additional UV enhancements include antireflection (AR) and solar-blind UV bandpass coatings prepared by atomic layer deposition. Quantum efficiency (QE) measurements show QE > 50% in the 100–300 nm range for detectors with simple AR coatings, and QE ≅ 80% at ~206 nm has been shown when more complex AR coatings are used. The second approach is based on avalanche photodiodes in III-nitride materials with high QE and intrinsic solar blindness. PMID:27338399

  9. Influence of epoxy resin as encapsulation material of silicon photovoltaic cells on maximum current

    Directory of Open Access Journals (Sweden)

    Acevedo-Gómez David

    2017-01-01

    Full Text Available This work presents an analysis about how the performance of silicon photovoltaic cells is influenced by the use of epoxy resin as encapsulation material with flat roughness. The effect of encapsulation on current at maximum power of mono-crystalline cell was tested indoor in a solar simulator bench at 1000 w/m² and AM1.5G. The results show that implementation of flat roughness layer onto cell surface reduces the maximum current inducing on average 2.7% less power with respect to a cell before any encapsulation. The losses of power and, in consequence, the less production of energy are explained by resin light absorption, reflection and partially neutralization of non-reflective coating.

  10. Humidity dependence of adhesion for silane coated microcantilevers

    International Nuclear Information System (INIS)

    De Boer, Maarten P.; Mayer, Thomas M.; Carpick, Robert W.; Michalske, Terry A.; Srinivasan, U.; Maboudian, R.

    1999-01-01

    This study examines adhesion between silane-coated micromachined surfaces that are exposed to humid conditions. Our quantitative values for interfacial adhesion energies are determined from an in-situ optical measurement of deformations in partly-adhered cantilever beams. We coated micromachined cantilevers with either ODTS (C(sub 18)H(sub 37)SiCl(sub 3)) or FDTS (C(sub 8)F(sub 17)C(sub 2)H(sub 4)SiCl(sub 3)) with the objective of creating hydrophobic surfaces whose adhesion would be independent of humidity. In both cases, the adhesion energy is significantly lower than for uncoated, hydrophilic surfaces. For relative humidities (RH) less than 95% (ODTS) and 80% (FDTS) the adhesion energy was extremely low and constant. In fact, ODTS-coated beams exposed to saturated humidity conditions and long (48 hour) exposures showed only a factor of two increase in adhesion energy. Surprisingly, FDTS coated beams, which initially have a higher contact angle (115(degree)) with water than do ODTS coated beams (112(degree)), proved to be much more sensitive to humidity. The FDTS coated surfaces showed a factor of one hundred increase in adhesion energy after a seven hour exposure to 90% RH. Atomic force microscopy revealed agglomerated coating material after exposed to high RH, suggesting a redistribution of the monolayer film. This agglomeration was more prominent for FDTS than ODTS. These findings suggest a new mechanism for uptake of moisture under high humidity conditions. At high humidities, the silane coatings can reconfigure from a surface to a bulk phase leaving behind locally hydrophilic sites which increase the average measured adhesion energy. In order for the adhesion increase to be observed, a significant fraction of the monolayer must be converted from the surface to the bulk phase

  11. Magnetic behavioural change of silane exposed graphene nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Sekhar C., E-mail: raysc@unisa.ac.za [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg 1710 (South Africa); Mishra, D. K. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg 1710 (South Africa); Department of Physics, Institute of Technical Research and Education, Siksha ‘O’ Anusandhan University, Khandagiri Square, Bhubaneswar 751030, Odisha (India); Strydom, A. M. [Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Papakonstantinou, P. [Nanotechnology and Integrated Bioengineering Center (NIBEC), School of Engineering, University of Ulster, Jordanstown Campus, Newtownabbey BT37 0QB (United Kingdom)

    2015-09-21

    The electronic structures and magnetic properties of graphene nanoflakes (GNFs) exposed to an organo-silane precursor [tetra-methyl-silane, Si(CH{sub 3}){sub 4}] were studied using atomic force microscopy, electron field emission (EFE), x-ray photoelectron spectroscopy (XPS), and magnetization. The result of XPS indicates that silyl radical based strong covalent bonds were formed in GNFs, which induced local structural relaxations and enhanced sp{sup 3} hybridization. The EFE measurements show an increase in the turn-on electric field from 9.8 V/μm for pure GNFs to 26.3 V/μm for GNFs:Si having highest Si/(Si + C) ratio ( ≅ 0.35) that also suggests an enhancement of the non-metallic sp{sup 3} bonding in the GNFs matrix. Magnetic studies show that the saturation magnetization (Ms) is decreased from 172.53 × 10{sup −6} emu/g for pure GNFs to 13.00 × 10{sup −6} emu/g for GNFs:Si with the highest Si/(Si + C) ratio 0.35, but on the other side, the coercivity (Hc) increases from 66 to 149 Oe due to conversion of sp{sup 2} → sp{sup 3}-hybridization along with the formation of SiC and Si-O bonding in GNFs. The decrease in saturation magnetization and increase in coercivity (Hc) in GNFs on Si-functionalization are another routes to tailor the magnetic properties of graphene materials for magnetic device applications.

  12. Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Muhammad [Department of Chemistry, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of); Rafiq, Muhammad; Seo, Sung-Yum [Department of Biology, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of); Lee, Ki Hwan, E-mail: khlee@kongju.ac.kr [Department of Chemistry, Kongju National University, Gongju, Chungnam 314-701 (Korea, Republic of)

    2014-07-01

    Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635–670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

  13. Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

    International Nuclear Information System (INIS)

    Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

    2014-01-01

    Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635–670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

  14. Determination of the Wetting Angle of Germanium and Germanium-Silicon Melts on Different Substrate Materials

    Science.gov (United States)

    Kaiser, Natalie; Croell, Arne; Szofran, F. R.; Cobb. S. D.; Dold, P.; Benz, K. W.

    1999-01-01

    During Bridgman growth of semiconductors detachment of the crystal and the melt meniscus has occasionally been observed, mainly under microgravity (microg) conditions. An important factor for detached growth is the wetting angle of the melt with the crucible material. High contact angles are more likely to result in detachment of the growing crystal from the ampoule wall. In order to achieve detached growth of germanium (Ge) and germanium-silicon (GeSi) crystals under 1g and microg conditions, sessile drop measurements were performed to determine the most suitable ampoule material as well as temperature dependence of the surface tension for GeSi. Sapphire, fused quartz, glassy carbon, graphite, SiC, pyrolytic Boron Nitride (pBN), AIN, and diamond were used as substrates. Furthermore, different cleaning procedures and surface treatments (etching, sandblasting, etc.) of the same substrate material and their effect on the wetting behavior were studied during these experiments. pBN and AIN substrates exhibited the highest contact angles with values around 170 deg.

  15. Evaluation of secondary crystallization effect in poly hydroxybutyrate and silanized coir dust composites

    International Nuclear Information System (INIS)

    Mello, Carolina C. de; Costa, Marysilvia F. da; Thire, Rossana M.S.M.

    2011-01-01

    Polyhydroxybutyrate is a natural and biodegradable polyester, susceptible to secondary crystallization when it is stored at environment temperature. Coir dust is an agroindustrial waste which has good prospects for use as filler in composites. In this context, PHB-coir dust composites were produced. The compatibilization was made by coir dust silanization. The secondary crystallization evolution on materials was evaluated by x-ray diffraction. Its effect was verified by tension tests which presented that elastic modulus increases when crystallinity increases. (author)

  16. Towards Cost-Effective Crystalline Silicon Based Flexible Solar Cells: Integration Strategy by Rational Design of Materials, Process, and Devices

    KAUST Repository

    Bahabry, Rabab R.

    2017-01-01

    . However, silicon is a brittle material with a fracture strains <1%. Highly flexible Si-based solar cells are available in the form thin films which seem to be disadvantageous over thick Si solar cells due to the reduction of the optical absorption

  17. Plasma-enhanced growth, composition, and refractive index of silicon oxy-nitride films

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    1995-01-01

    Secondary ion mass spectrometry and refractive index measurements have been carried out on silicon oxy-nitride produced by plasma-enhanced chemical vapor deposition (PECVD). Nitrous oxide and ammonia were added to a constant flow of 2% silane in nitrogen, to produce oxy-nitride films with atomic...... nitrogen concentrations between 2 and 10 at. %. A simple atomic valence model is found to describe both the measured atomic concentrations and published material compositions for silicon oxy-nitride produced by PECVD. A relation between the Si–N bond concentration and the refractive index is found......-product. A model, that combine the chemical net reaction and the stoichiometric rules, is found to agree with measured deposition rates for given material compositions. Effects of annealing in a nitrogen atmosphere has been investigated for the 400 °C– 1100 °C temperature range. It is observed that PECVD oxy...

  18. Low cost solar array project. Cell and module formation research area. Process research of non-CZ silicon material

    Science.gov (United States)

    1983-01-01

    Liquid diffusion masks and liquid dopants to replace the more expensive CVD SiO2 mask and gaseous diffusion processes were investigated. Silicon pellets were prepared in the silicon shot tower; and solar cells were fabricated using web grown where the pellets were used as a replenishment material. Verification runs were made using the boron dopant and liquid diffusion mask materials. The average of cells produced in these runs was 13%. The relationship of sheet resistivity, temperature, gas flows, and gas composition for the diffusion of the P-8 liquid phosphorus solution was investigated. Solar cells processed from web grown from Si shot material were evaluated, and results qualified the use of the material produced in the shot tower for web furnace feed stock.

  19. Tenth Workshop on Crystalline Silicon Solar Cell Materials and Processes: A Summary of Discussion Sessions

    Energy Technology Data Exchange (ETDEWEB)

    Tan, T.; Swanson, D.; Sinton, R.; Sopori, B.

    2001-01-22

    The 10th Workshop on Silicon Solar Cell Materials and Processes was held in Copper Mountain, Colorado, on August 13-16, 2000. The workshop was attended by 85 scientists and engineers from 15 international photovoltaic (PV) companies and 24 research institutions. Review and poster presentations were augmented by discussion sessions to address the recent progress and critical issues in meeting the goals for Si in the PV Industry Roadmap. The theme of the workshop was Si Photovoltaics: 10 Years of Progress and Opportunities for the Future. Two special sessions were held: Advanced Metallization and Interconnections - covering recent advances in solar cell metallization, printed contacts and interconnections, and addressing new metallization schemes for low-cost cell interconnections; and Characterization Methods - addressing the growing need for process monitoring techniques in the PV industry. The following major issues emerged from the discussion sessions: (1) Mechanical breakage in the P V industry involves a large fraction, about 5%-10%, of the wafers. (2) The current use of Al screen-printed back-contacts appears to be incompatible with the PV Industry Roadmap requirements. (3) The PV manufacturers who use hydrogen passivation should incorporate the plasma-enhanced chemical vapor deposited (PECVD) nitride for antireflection coating and hydrogenation. (4) There is an imminent need to dissolve metallic precipitates to minimize the electrical shunt problem caused by the ''bad'' regions in wafers. (5) Industry needs equipment for automated, in-line monitoring and testing. There are simply not many tools available to industry. (6) In the Wrap-Up Session of the workshop, there was consensus to create four industry/university teams that would address critical research topics in crystalline silicon. (7) The workshop attendees unanimously agreed that the workshop has served well the PV community by promoting the fundamental understanding of industrial

  20. Silanization of boron nitride nanosheets (BNNSs) through microfluidization and their use for producing thermally conductive and electrically insulating polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Seyhan, A.Tuğrul, E-mail: atseyhan@anadolu.edu.tr [Department of Materials Science and Engineering, Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey); Composite Materials Manufacturing Science Laboratory (CMMSL), Research and Application Center of Civil Aviation (RACCA), Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey); Göncü, Yapıncak; Durukan, Oya; Akay, Atakan; Ay, Nuran [Department of Materials Science and Engineering, Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey)

    2017-05-15

    Chemical exfoliation of boron nitride nanosheets (BNNSs) from large flakes of specially synthesized micro-sized hexagonal boron nitride (h-BN) ceramics was carried out through microfluidization. The surface of BNNSs obtained was then functionalized with vinyl-trimethoxy silane (VTS) coupling agent through microfluidization once again in an effort to make them compatible with organic materials, especially those including polymers. The morphology of BNNSs with and without silane treatment was then systematically characterized by conducting various different analytical techniques, including Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Bright field Transmission Electron Microscopy (BF-TEM), Contact angle analyzer (CAA), Particle size analyzer (PSA) and Fourier Transmission Infrared (FTIR) spectroscopy attached with attenuated total reflectance (ATR) module. As a result, the silane treatment was determined to be properly and successfully carried out and to give rise to the irregularity of large flakes of the BNNSs by folding back their free edges upon themselves, which in turn assists in inducing further exfoliation of the few-layered nanosheets. To gain more insight into the effectiveness of the surface functionalization, thermal conductivity of polypropylene (PP) nanocomposites containing different amounts (1 wt% and 5 wt%) of BNNSs with and without silane treatment was experimentally investigated. Regardless of the weight content, PP nanocomposites containing silanized BNNSs were found to exhibit high thermal conductivity compared to PP nanocomposites containing BNNSs without silane treatment. It was concluded that microfluidization possesses the robustness to provide a reliable product quality, whether in small or large quantities, in a very time effective manner, when it comes to first exfoliating two-dimensional inorganic materials into few layered sheets, and functionalizing the surface of these sheets afterwards

  1. Porous silicon carbide and aluminum oxide with unidirectional open porosity as model target materials for radioisotope beam production

    CERN Document Server

    Czapski, M; Tardivat, C; Stora, T; Bouville, F; Leloup, J; Luis, R Fernandes; Augusto, R Santos

    2013-01-01

    New silicon carbide (SiC) and aluminum oxide (Al2O3) of a tailor-made microstructure were produced using the ice-templating technique, which permits controlled pore formation conditions within the material. These prototypes will serve to verify aging of the new advanced target materials under irradiation with proton beams. Before this, the evaluation of their mechanical integrity was made based on the energy deposition spectra produced by FLORA codes. (C) 2013 Elsevier B.V. All rights reserved.

  2. Porous silicon carbide and aluminum oxide with unidirectional open porosity as model target materials for radioisotope beam production

    Science.gov (United States)

    Czapski, M.; Stora, T.; Tardivat, C.; Deville, S.; Santos Augusto, R.; Leloup, J.; Bouville, F.; Fernandes Luis, R.

    2013-12-01

    New silicon carbide (SiC) and aluminum oxide (Al2O3) of a tailor-made microstructure were produced using the ice-templating technique, which permits controlled pore formation conditions within the material. These prototypes will serve to verify aging of the new advanced target materials under irradiation with proton beams. Before this, the evaluation of their mechanical integrity was made based on the energy deposition spectra produced by FLUKA codes.

  3. Graphene synthesized on porous silicon for active electrode material of supercapacitors

    Science.gov (United States)

    Su, B. B.; Chen, X. Y.; Halvorsen, E.

    2016-11-01

    We present graphene synthesized by chemical vapour deposition under atmospheric pressure on both porous nanostructures and flat wafers as electrode scaffolds for supercapacitors. A 3nm thin gold layer was deposited on samples of both porous and flat silicon for exploring the catalytic influence during graphene synthesis. Micro-four-point probe resistivity measurements revealed that the resistivity of porous silicon samples was nearly 53 times smaller than of the flat silicon ones when all the samples were covered by a thin gold layer after the graphene growth. From cyclic voltammetry, the average specific capacitance of porous silicon coated with gold was estimated to 267 μF/cm2 while that without catalyst layer was 145μF/cm2. We demonstrated that porous silicon based on nanorods can play an important role in graphene synthesis and enable silicon as promising electrodes for supercapacitors.

  4. Graphene synthesized on porous silicon for active electrode material of supercapacitors

    International Nuclear Information System (INIS)

    Su, B B; Chen, X Y; Halvorsen, E

    2016-01-01

    We present graphene synthesized by chemical vapour deposition under atmospheric pressure on both porous nanostructures and flat wafers as electrode scaffolds for supercapacitors. A 3nm thin gold layer was deposited on samples of both porous and flat silicon for exploring the catalytic influence during graphene synthesis. Micro-four-point probe resistivity measurements revealed that the resistivity of porous silicon samples was nearly 53 times smaller than of the flat silicon ones when all the samples were covered by a thin gold layer after the graphene growth. From cyclic voltammetry, the average specific capacitance of porous silicon coated with gold was estimated to 267 μF/cm 2 while that without catalyst layer was 145μF/cm 2 . We demonstrated that porous silicon based on nanorods can play an important role in graphene synthesis and enable silicon as promising electrodes for supercapacitors. (paper)

  5. Pemanfaatan serat silicon carbon dan partikel alumina pada matrik aluminium untuk meningkatkan sifat mekanis material komposit

    Directory of Open Access Journals (Sweden)

    Ketut Suarsana

    2017-03-01

    Full Text Available Abstrak: Pemanfaatan penguat material komposit berbasis serat dan juga partikel pada pembuatan bahan komposit sekarang ini sangatpotensial untuk dikembangkan dan diteliti. Beragam sumber serat dan juga penguat dalam bentuk partikel bisa didapat dari seratalami dari tumbuh-tubuhan dan juga serat yang sudah dikenakan perlakuan sebelumnya. Indonesia memiliki potensi sumberalam yang sangat potensial terutama sebgai sumber serat dari tumbuhan juga berupa logam aluminium (bauxite dari fosil.Bahan ini dapat dimanfaatkan untuk kebutuhan masyarakat industri sebagai bahan dasar pembuatan komposit bermatrikAluminium dan sebagai penguat berupa serat maupun partikel alumina. Metode pembuatan Aluminum Matrix Composite (AMCdengan proses metalurgi serbuk pada gaya tekan/kompaksi 2,5 ton mengunakan alat press hydrolik, waktu penahanan 15menit, serta proses perlakuan pada variasi komposisi berat (%wt. Variasi komposisi penguat serat Silicon Carbon (SiC danAl2O3 (alumina pada matrik Aluminium adalah : 30% SiC + 0% Al203, 27% SiC + 3% Al203, 24% SiC + 6% Al203 dan 21% SiC+ 9% Al203 dengan matrik 70% Al, pada kondisi tempertaur 500oC, 550oC dan 600oC. Setelah material komposit terbentuk, diujiuntuk mengetahui sifat mekanik akibat pengaruh variasi komposisi antara matrik dan penguatan pada komposit. Uji karakteristikdilakukan di laboratorium untuk menggetahui sifat kekuatan dan kekerasan material komposit. Selanjutnya dicari hubunganantara sifat masing-masing komposisi penguat serat SiC dan Al2O3 pembentuk komposit yang dibuat untuk mengetahui manfaatdari penguat serat dan partikel alumina.Kata Kunci: Sifat kekuatan, kekerasan, serat SiC dan Al2O3 Abstract: Utilization reinforcement fiber-based composite material and particles in the manufacture of composite materials now havepotential to be developed and researched. Various sources of fiber and reinforcement in particle form can be obtained fromnatural fibers from plants and fiber that has been subjected to a

  6. Comparisons between a gas-phase model of silane chemical vapor deposition and laser-diagnostic measurements

    International Nuclear Information System (INIS)

    Breiland, W.G.; Coltrin, M.E.; Ho, P.

    1986-01-01

    Theoretical modeling and experimental measurements have been used to study gas-phase chemistry in the chemical vapor deposition (CVD) of silicon from silane. Pulsed laser Raman spectroscopy was used to obtain temperature profiles and to obtain absolute density profiles of silane during deposition at atmospheric and 6-Torr total pressures for temperatures ranging from 500 to 800 0 C. Laser-excited fluorescence was used to obtain relative density profiles of Si 2 during deposition at 740 0 C in helium with 0-12 Torr added hydrogen. These measurements are compared to predictions from the theoretical model of Coltrin, Kee, and Miller. The predictions agree qualitatively with experiment. These studies indicate that fluid mechanics and gas-phase chemical kinetics are important considerations in understanding the chemical vapor deposition process

  7. Materials and Light Management for High-Efficiency Thin-Film Silicon Solar Cells

    OpenAIRE

    Tan, H.

    2015-01-01

    Direct conversion of sunlight into electricity is one of the most promising approaches to provide sufficient renewable energy for humankind. Solar cells are such devices which can efficiently generate electricity from sunlight through the photovoltaic effect. Thin-film silicon solar cells, a type of photovoltaic (PV) devices which deploy the chemical-vapor-deposited hydrogenated amorphous silicon (a-Si:H) and nanocrystalline silicon (nc-Si:H) and their alloys as the absorber layers and doped ...

  8. Market Opportunity of Some Aluminium Silicon Alloys Materials through Changing the Casting Process

    Directory of Open Access Journals (Sweden)

    Delfim SOARES

    2012-08-01

    Full Text Available Fatigue is considered to be the most common mechanism by which engineering components fail, and it accounts for at least 90% of all service failures attributed to mechanical causes. Mechanical properties (tensile strength, tensile strain, Young modulus, etc as well as fatigue properties (fatigue life are very dependent on casting method. The most direct effects of casting techniques are on the metallurgical microstructure that bounds the mechanical properties. One of the important variables affected by the casting technique is the cooling rate which is well known to strongly restrict the microstructure. In the present research has been done a comparison of fatigue properties of two aluminum silicon alloys obtained by two casting techniques. It was observed that the fatigue life is increasing with 24% for Al12Si and 31% for AL18Si by using centrifugal casting process instead of gravity casting. This increasing in fatigue life means that a component tailored from materials obtained by centrifugal casting will stay longer in service. It was made an estimation of the time required to recover the costs of technology in order to use the centrifuge process that will allow to obtain materials with improved properties. The amortization can be achieved by using two different marketing techniques: through the release of the product at the old price and with much longer life of the component which means "same price - longer life", or increasing price, by highlighting new product performance which means "higher price - higher properties".

  9. Irradiation study of different silicon materials for the CMS tracker upgrade

    CERN Document Server

    Erfle, Joachim; Hansen, Wolfgang; Garutti, Erika

    Around 2022, an upgrade of the LHC collider complex is planned to significantly increase the luminosity (the High Luminosity LHC, HL-LHC). This means that the experiments have to cope with a higher number of collisions per bunch crossing and survive in a radiation environment much harsher than that at the present LHC. Especially the tracking detectors have to be improved for the HL-LHC. The increased number of tracks requires an increase of the number of readout channels while the higher radiation makes new sensor materials necessary. Within CMS, a measurement campaign was initiated to study the performance of different silicon materials in a corresponding radiation environment. To simulate the expected radiation the samples were irradiated with neutrons and with protons with two different energies. Radiation damage can be divided in two categories. First, ionizing energy loss in the surface isolation layers of the sensor leads to a change of the concentration of charged states in the sensor surface and there...

  10. Tribology and Stability of Organic Monolayers on CrN: A Comparison among Silane, Phosphate, Alkene, and Alkyne Chemistries

    NARCIS (Netherlands)

    Pujari, S.P.; Li, F.; Regeling, R.; Zuilhof, H.

    2013-01-01

    The fabrication of chemically and mechanically stable monolayers on the surfaces of various inorganic hard materials is crucial to the development of biomedical/electronic devices. In this Article, monolayers based on the reactivity of silane, phosphonate, 1-alkene, and 1-alkyne moieties were

  11. Protein deposition on a lathe-cut silicone hydrogel contact lens material.

    Science.gov (United States)

    Subbaraman, Lakshman N; Woods, Jill; Teichroeb, Jonathan H; Jones, Lyndon

    2009-03-01

    To determine the quantity of total protein, total lysozyme, and the conformational state of lysozyme deposited on a novel, lathe-cut silicone hydrogel (SiHy) contact lens material (sifilcon A) after 3 months of wear. Twenty-four subjects completed a prospective, bilateral, daily-wear, 9-month clinical evaluation in which the subjects were fitted with a novel, custom-made, lathe-cut SiHy lens material. The lenses were worn for three consecutive 3-month periods, with lenses being replaced after each period of wear. After 3 months of wear, the lenses from the left eye were collected and assessed for protein analysis. The total protein deposited on the lenses was determined by a modified Bradford assay, total lysozyme using Western blotting and the lysozyme activity was determined using a modified micrococcal assay. The total protein recovered from the custom-made lenses was 5.3 +/- 2.3 microg/lens and the total lysozyme was 2.4 +/- 1.2 microg/lens. The denatured lysozyme found on the lenses was 1.9 +/- 1.0 microg/lens and the percentage of lysozyme denatured was 80 +/- 10%. Even after 3 months of wear, the quantity of protein and the conformational state of lysozyme deposited on these novel lens materials was very similar to that found on similar surface-coated SiHy lenses after 2 to 4 weeks of wear. These results indicate that extended use of the sifilcon A material is not deleterious in terms of the quantity and quality of protein deposited on the lens.

  12. Removal of Silicone Oil From Intraocular Lens Using Novel Surgical Materials

    Science.gov (United States)

    Paschalis, Eleftherios I.; Eliott, Dean; Vavvas, Demetrios G.

    2014-01-01

    Purpose To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery. Methods Three different designs were fabricated using soft lithography of polydimethylsiloxane (PDMS), three-dimensional (3D) inverse PDMS fabrication using water dissolvable particles, and atomic layer deposition (ALD) of alumina (Al2O3) on surgical cellulose fibers. Laboratory tests included static and dynamic contact angle (CA) measurements with water and SiO, nondestructive x-ray microcomputer tomography (micro-CT), and microscopy. SiO removal was performed in vitro and ex vivo using implantable IOLs and explanted porcine eyes. Results All designs exhibited enhanced hydrophobicity and oleophilicity. Static CA measurements with water ranged from 131° to 160° and with SiO CA approximately 0° in 120 seconds following exposure. Nondestructive x-ray analysis of the 3D PDMS showed presence of interconnected polydispersed porosity of 100 to 300 μm in diameter. SiO removal from IOLs was achieved in vitro and ex vivo using standard 20-G vitrectomy instrumentation. Conclusion Removal of SiO from IOLs can be achieved using materials with lower surface energy than that of the IOLs. This can be achieved using appropriate surface chemistry and surface topography. Three designs, with enhanced hydrophobic properties, were fabricated and tested in vitro and ex vivo. All materials remove SiO within an aqueous environment. Preliminary ex vivo results were very promising, opening new possibilities for SiO removal in vitreoretinal surgeries. Translational Relevance This is the first report of an instrument that can lead to successful removal of SiO from the surface of IOL. In addition to the use of this instrument/material in medicine it can also be used in the industry, for example, retrieval of oil spills from bodies of water. PMID:25237593

  13. Removal of Silicone Oil From Intraocular Lens Using Novel Surgical Materials.

    Science.gov (United States)

    Paschalis, Eleftherios I; Eliott, Dean; Vavvas, Demetrios G

    2014-09-01

    To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery. Three different designs were fabricated using soft lithography of polydimethylsiloxane (PDMS), three-dimensional (3D) inverse PDMS fabrication using water dissolvable particles, and atomic layer deposition (ALD) of alumina (Al 2 O 3 ) on surgical cellulose fibers. Laboratory tests included static and dynamic contact angle (CA) measurements with water and SiO, nondestructive x-ray microcomputer tomography (micro-CT), and microscopy. SiO removal was performed in vitro and ex vivo using implantable IOLs and explanted porcine eyes. All designs exhibited enhanced hydrophobicity and oleophilicity. Static CA measurements with water ranged from 131° to 160° and with SiO CA approximately 0° in 120 seconds following exposure. Nondestructive x-ray analysis of the 3D PDMS showed presence of interconnected polydispersed porosity of 100 to 300 μm in diameter. SiO removal from IOLs was achieved in vitro and ex vivo using standard 20-G vitrectomy instrumentation. Removal of SiO from IOLs can be achieved using materials with lower surface energy than that of the IOLs. This can be achieved using appropriate surface chemistry and surface topography. Three designs, with enhanced hydrophobic properties, were fabricated and tested in vitro and ex vivo. All materials remove SiO within an aqueous environment. Preliminary ex vivo results were very promising, opening new possibilities for SiO removal in vitreoretinal surgeries. This is the first report of an instrument that can lead to successful removal of SiO from the surface of IOL. In addition to the use of this instrument/material in medicine it can also be used in the industry, for example, retrieval of oil spills from bodies of water.

  14. Advanced Non-Destructive Assessment Technology to Determine the Aging of Silicon Containing Materials for Generation IV Nuclear Reactors

    Science.gov (United States)

    Koenig, T. W.; Olson, D. L.; Mishra, B.; King, J. C.; Fletcher, J.; Gerstenberger, L.; Lawrence, S.; Martin, A.; Mejia, C.; Meyer, M. K.; Kennedy, R.; Hu, L.; Kohse, G.; Terry, J.

    2011-06-01

    To create an in-situ, real-time method of monitoring neutron damage within a nuclear reactor core, irradiated silicon carbide samples are examined to correlate measurable variations in the material properties with neutron fluence levels experienced by the silicon carbide (SiC) during the irradiation process. The reaction by which phosphorus doping via thermal neutrons occurs in the silicon carbide samples is known to increase electron carrier density. A number of techniques are used to probe the properties of the SiC, including ultrasonic and Hall coefficient measurements, as well as high frequency impedance analysis. Gamma spectroscopy is also used to examine residual radioactivity resulting from irradiation activation of elements in the samples. Hall coefficient measurements produce the expected trend of increasing carrier concentration with higher fluence levels, while high frequency impedance analysis shows an increase in sample impedance with increasing fluence.

  15. Determinations of silicon and phosphorus in Pepperbush standard reference material by neutron activation and x-ray fluorescence methods

    International Nuclear Information System (INIS)

    Mizumoto, Yoshihiko; Nishio, Hirofumi; Hayashi, Takeshi; Kusakabe, Toshio; Iwata, Shiro.

    1987-01-01

    Silicon and phosphorus contents in Pepperbush standard reference material were determined by neutron activation and X-ray fluorescence methods. In neutron activation analysis, β-ray spectra of 32 P produced by 31 P(n,γ) 32 P reaction on Pepperbush and standard samples were measured by a low background β-ray spectrometer. In X-ray fluorescence analysis, the standard samples were prepared by mixing the Pepperbush powder with silicon dioxide and diammonium hydrogenphosphate. Characteristic X-rays from the samples were analyzed by a wavelength dispersive X-ray fluorescence spectrometer. From the β and X-ray intensities, silicon and phosphorus contents in Pepperbush were determined to be 1840 ± 80 and 1200 ± 50 μg g -1 , respectively. (author)

  16. Study program to develop and evaluate die and container materials for the growth of silicon ribbons. [for development of low cost solar cells

    Science.gov (United States)

    Addington, L. A.; Ownby, P. D.; Yu, B. B.; Barsoum, M. W.; Romero, H. V.; Zealer, B. G.

    1979-01-01

    The development and evaluation of proprietary coatings of pure silicon carbide, silicon nitride, and aluminum nitride on less pure hot pressed substrates of the respective ceramic materials, is described. Silicon sessile drop experiments were performed on coated test specimens under controlled oxygen partial pressure. Prior to testing, X-ray diffraction and SEM characterization was performed. The reaction interfaces were characterized after testing with optical and scanning electron microscopy and Auger electron spectroscopy. Increasing the oxygen partial pressure was found to increase the molten silicon contact angle, apparently because adsorbed oxygen lowers the solid-vapor interfacial free energy. It was also found that adsorbed oxygen increased the degree of attack of molten silicon upon the chemical vapor deposited coatings. Cost projections show that reasonably priced, coated, molten silicon resistant refractory material shapes are obtainable.

  17. Physico-mechanical properties of silanized-montmorillonite reinforced chitosan-co-poly(maleic anhydride) composites

    Science.gov (United States)

    Saputra, O. A.; Fajrin, A.; Nauqinida, M.; Suryanti, V.; Pramono, E.

    2017-07-01

    To solve the problems of dependence on petroleum as starting material in the manufacturing of plastics in Indonesia, green plastic from biopolymer like chitosan to be one of promising options and alternative to replace the conventional plastics. However, to overcome the mechanical and physical properties of chitosan, the addition of reinforcement agent was introduced. In this study, silanized-montmorillonite (sMMt) has been prepared as a reinforcement agent in the chitosan-co-poly(maleic anhydride) (referred as Cs-MAH) matrix. Silanizing of montmorillonite is one of strategy to improve the interaction between montmorillonite and chitosan, consequently, the mechanical properties, tensile strength of composites contained 6 phr of sMMt improved 56.5% to chitosan. Moreover, the presence both MAH and sMMt on the comosites also reduced swelling degree and swelling area by 20.6% and 26.7%.

  18. Electron spin resonance investigaton of semiconductor materials for application in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Lihong

    2012-07-01

    In the present work, hydrogenated silicon and its alloys silicon carbide and silicon oxide have been investigated using electron spin resonance (ESR). The microstructure of these materials ranges from highly crystalline to amorphous. The correlation between the paramagnetic defects, microstructure, optical and electrical properties has been discussed. Correspondingly, these properties were characterized by the spin density (N{sub S}), g-value and the lineshape of ESR spectra, Infrared (I{sup IR}{sub C}) and/or Raman crystallinity (I{sup RS}{sub C}) as well as optical absorption and electrical dark conductivity ({sigma}{sub D}). 1. As the light absorber, Si layers essentially should have low defect density and good stability against light exposure. The spin density (N{sub S}) measured by ESR is often used as a measure for the paramagnetic defect density (N{sub D}) in the material. However, ESR sample preparation procedures can potentially cause discrepancy between N{sub S} and N{sub D}. Using Mo-foil, Al-foil and ZnO:Al-covered glass as sacrificial substrates, {mu}c-Si:H and a-Si:H films were deposited by plasma-enhanced chemical vapor deposition (PECVD), and ESR powder samples have been prepared with corresponding procedures. Possible preparation-related metastability and instability effects have been investigated in terms of substrate dependence, HCl-etching and atmosphere exposure. A sequence of 'preparation - annealing - air-exposure - annealing' has been designed to investigate the metastability and instability effects. N{sub S} after post-preparation air exposure is higher than in the annealed states, especially for the highly crystalline {mu}c-Si:H material the discrepancy reached one order of magnitude. Low temperature ESR measurements at 40 K indicated that atmospheric exposure leads to a redistribution of the defect states which in turn influence the evaluated N{sub S}. In annealed conditions the samples tend to have lower N{sub S} presumably due

  19. Efficient Flame Detection and Early Warning Sensors on Combustible Materials Using Hierarchical Graphene Oxide/Silicone Coatings.

    Science.gov (United States)

    Wu, Qian; Gong, Li-Xiu; Li, Yang; Cao, Cheng-Fei; Tang, Long-Cheng; Wu, Lianbin; Zhao, Li; Zhang, Guo-Dong; Li, Shi-Neng; Gao, Jiefeng; Li, Yongjin; Mai, Yiu-Wing

    2018-01-23

    Design and development of smart sensors for rapid flame detection in postcombustion and early fire warning in precombustion situations are critically needed to improve the fire safety of combustible materials in many applications. Herein, we describe the fabrication of hierarchical coatings created by assembling a multilayered graphene oxide (GO)/silicone structure onto different combustible substrate materials. The resulting coatings exhibit distinct temperature-responsive electrical resistance change as efficient early warning sensors for detecting abnormal high environmental temperature, thus enabling fire prevention below the ignition temperature of combustible materials. After encountering a flame attack, we demonstrate extremely rapid flame detection response in 2-3 s and excellent flame self-extinguishing retardancy for the multilayered GO/silicone structure that can be synergistically transformed to a multiscale graphene/nanosilica protection layer. The hierarchical coatings developed are promising for fire prevention and protection applications in various critical fire risk and related perilous circumstances.

  20. Elastic silicone encapsulation of n-hexadecyl bromide by microfluidic approach as novel microencapsulated phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Zhenjin [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Su, Lin; Li, Jing; Yang, Ruizhuang; Zhang, Zhanwen; Liu, Meifang; Li, Jie [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Li, Bo, E-mail: LB6711@126.com [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China)

    2014-08-20

    Highlights: • n-Hexadecyl bromide was encapsuled in elastic silicone shell. • The surfaces of microcapsules were smooth and the cross sections were compact. • Latent heat of microcapsules was 76.35 J g{sup −1}. • The microencapsulation ratio was 49 wt.%. • The microcapsules had good thermal stability. - Abstract: The elastic silicone/n-hexadecyl bromide microcapsules were prepared as novel microencapsulated phase change materials by microfluidic approach with the co-flowing channels, where the double oil1-in-oil2-in-water (O1/O2/W) droplets with a core–shell geometry were fabricated. The thermal characterizations of the microcapsules were investigated using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The DSC results showed that the microcapsules had good energy storage capacity with melting and freezing enthalpies 76.35 J g{sup −1} and 78.67 J g{sup −1}, respectively. The TGA investigation showed that the microcapsules had good thermal stability. The surfaces of microcapsules were smooth and the cross sections were compact from the results of optical microscope and scanning electron microscopy (SEM). Optical microscope showed that the silicone shell can provide expansion place due to its elastic property. Therefore, the silicone/n-hexadecyl bromide microcapsules showed good potential as thermal regulating textile and thermal insulation materials.

  1. Elastic silicone encapsulation of n-hexadecyl bromide by microfluidic approach as novel microencapsulated phase change materials

    International Nuclear Information System (INIS)

    Fu, Zhenjin; Su, Lin; Li, Jing; Yang, Ruizhuang; Zhang, Zhanwen; Liu, Meifang; Li, Jie; Li, Bo

    2014-01-01

    Highlights: • n-Hexadecyl bromide was encapsuled in elastic silicone shell. • The surfaces of microcapsules were smooth and the cross sections were compact. • Latent heat of microcapsules was 76.35 J g −1 . • The microencapsulation ratio was 49 wt.%. • The microcapsules had good thermal stability. - Abstract: The elastic silicone/n-hexadecyl bromide microcapsules were prepared as novel microencapsulated phase change materials by microfluidic approach with the co-flowing channels, where the double oil1-in-oil2-in-water (O1/O2/W) droplets with a core–shell geometry were fabricated. The thermal characterizations of the microcapsules were investigated using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The DSC results showed that the microcapsules had good energy storage capacity with melting and freezing enthalpies 76.35 J g −1 and 78.67 J g −1 , respectively. The TGA investigation showed that the microcapsules had good thermal stability. The surfaces of microcapsules were smooth and the cross sections were compact from the results of optical microscope and scanning electron microscopy (SEM). Optical microscope showed that the silicone shell can provide expansion place due to its elastic property. Therefore, the silicone/n-hexadecyl bromide microcapsules showed good potential as thermal regulating textile and thermal insulation materials

  2. Process for making silicon

    Science.gov (United States)

    Levin, Harry (Inventor)

    1987-01-01

    A reactor apparatus (10) adapted for continuously producing molten, solar grade purity elemental silicon by thermal reaction of a suitable precursor gas, such as silane (SiH.sub.4), is disclosed. The reactor apparatus (10) includes an elongated reactor body (32) having graphite or carbon walls which are heated to a temperature exceeding the melting temperature of silicon. The precursor gas enters the reactor body (32) through an efficiently cooled inlet tube assembly (22) and a relatively thin carbon or graphite septum (44). The septum (44), being in contact on one side with the cooled inlet (22) and the heated interior of the reactor (32) on the other side, provides a sharp temperature gradient for the precursor gas entering the reactor (32) and renders the operation of the inlet tube assembly (22) substantially free of clogging. The precursor gas flows in the reactor (32) in a substantially smooth, substantially axial manner. Liquid silicon formed in the initial stages of the thermal reaction reacts with the graphite or carbon walls to provide a silicon carbide coating on the walls. The silicon carbide coated reactor is highly adapted for prolonged use for production of highly pure solar grade silicon. Liquid silicon (20) produced in the reactor apparatus (10) may be used directly in a Czochralski or other crystal shaping equipment.

  3. Electrochemical characteristics of bundle-type silicon nanorods as an anode material for lithium ion batteries

    International Nuclear Information System (INIS)

    Nguyen, Si Hieu; Lim, Jong Choo; Lee, Joong Kee

    2012-01-01

    Highlights: ► A metal-assisted chemical etching technique was performed on Si thin films. ► The etching process resulted in the formation of bundle-type Si nanorods. ► The morphology of Si electrodes closely relate to electrochemical characteristics. - Abstract: In order to prepare bundle-type silicon nanorods, a silver-assisted chemical etching technique was used to modify a 1.6 μm silicon thin film, which was deposited on Cu foil by Electron Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition. The bundle-type silicon nanorods on Cu foil were employed as anodes for a lithium secondary battery, without further treatment. The electrochemical characteristics of the pristine silicon thin film anodes and the bundle-type silicon nanorod anodes are different from one another. The electrochemical performance of the bundle-type silicon nanorod anodes exceeded that of the pristine Si thin film anodes. The specific capacity of the bundle-type silicon nanorod anodes is much higher than 3000 mAh g −1 at the first charge (Li insertion) cycle. The coulombic efficiency of bundle-type silicon anodes was stable at more than 97%, and the charge capacity remained at 1420 mAh g −1 , even after 100 cycles of charging and discharging. The results from the differential voltage analysis showed a side reaction at around 0.44–0.5 V, and the specific potential of this side reaction decreased after each cycle. The apparent diffusion coefficients of the two anode types were in the range of 10 −13 –10 −16 cm 2 s −1 in the first cycle. In subsequent charge cycles, these values for the silicon thin film anodes and the silicon nanorod bundle anode were approximately 10 −12 –10 −14 and 10 −13 –10 −15 cm 2 s −1 , respectively.

  4. Silane coupling agent for enhanced epoxy-iron oxide nanocomposite

    Directory of Open Access Journals (Sweden)

    Hamdy M. Naguib

    2018-01-01

    Full Text Available In this study, silane-treated Fe2O3 nanoparticles were successfully prepared using (3-aminopropyl triethoxysilane (APTES. The chemical structure and morphology of the obtained nanoparticles were investigated by several analysis techniques including FTIR, XRD, TEM and DLS. Both of untreated Fe2O3 (IO and silane-treated Fe2O3 (SIO nanoparticles were used in the preparation of epoxy nanocomposites with 5% by weight fraction. FTIR and XRD approved that SIO was successfully prepared with highly crystalline structure. TEM and DLS indicated the good dispersion of treated nanoparticles in the nanocomposite matrix, also the average particle size of nanofiller decreased to ∼200 nm after silane treatment. The dynamic properties for the prepared nanocomposites were studied using DMA and confirmed by nanoindentation technique. The results indicated that silane-treated nanoparticles can improve the hardness and Tg by 87.5% and 5 °C respectively at 5% weight fraction.

  5. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Science.gov (United States)

    Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

    2011-10-01

    Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  6. Oxidation behaviour of silicon-free tungsten alloys for use as the first wall material

    Science.gov (United States)

    Koch, F.; Brinkmann, J.; Lindig, S.; Mishra, T. P.; Linsmeier, Ch

    2011-12-01

    The use of self-passivating tungsten alloys as armour material of the first wall of a fusion power reactor may be advantageous concerning safety issues. In earlier studies good performance of the system W-Cr-Si was demonstrated. Thin films of such alloys showed a strongly reduced oxidation rate compared to pure tungsten. However, the formation of brittle tungsten silicides may be disadvantageous for the powder metallurgical production of bulk W-Cr-Si alloys if a good workability is needed. This paper shows the results of screening tests to identify suitable silicon-free alloys with distinguished self-passivation and a potentially good workability. Of all the tested systems W-Cr-Ti alloys showed the most promising results. The oxidation rate was even lower than the one of W-Cr-Si alloys, the reduction factor was about four orders of magnitude compared to pure tungsten. This performance could be conserved even if the content of alloying elements was reduced.

  7. Oxidation behaviour of silicon-free tungsten alloys for use as the first wall material

    International Nuclear Information System (INIS)

    Koch, F; Brinkmann, J; Lindig, S; Mishra, T P; Linsmeier, Ch

    2011-01-01

    The use of self-passivating tungsten alloys as armour material of the first wall of a fusion power reactor may be advantageous concerning safety issues. In earlier studies good performance of the system W-Cr-Si was demonstrated. Thin films of such alloys showed a strongly reduced oxidation rate compared to pure tungsten. However, the formation of brittle tungsten silicides may be disadvantageous for the powder metallurgical production of bulk W-Cr-Si alloys if a good workability is needed. This paper shows the results of screening tests to identify suitable silicon-free alloys with distinguished self-passivation and a potentially good workability. Of all the tested systems W-Cr-Ti alloys showed the most promising results. The oxidation rate was even lower than the one of W-Cr-Si alloys, the reduction factor was about four orders of magnitude compared to pure tungsten. This performance could be conserved even if the content of alloying elements was reduced.

  8. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    International Nuclear Information System (INIS)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T; Padipatvuthikul, P

    2011-01-01

    Silicon nitride (Si 3 N 4 ) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si 3 N 4 ceramic as a dental core material. The white Si 3 N 4 was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si 3 N 4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si 3 N 4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder ( 2 O 3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si 3 N 4 specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10 -6 deg. C -1 , rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  9. 14th Workshop on Crystalline Silicon Solar Cells& Modules: Materials and Processes; Extended Abstracts and Papers

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B. L.

    2004-08-01

    The 14th Workshop will provide a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. It will offer an excellent opportunity for researchers in private industry and at universities to prioritize mutual needs for future collaborative research. The workshop is intended to address the fundamental properties of PV silicon, new solar cell designs, advanced solar cell processing techniques, and cell-related module issues. A combination of oral presentations by invited speakers, poster sessions, and discussion sessions will review recent advances in crystal growth, new cell designs, new processes and process characterization techniques, cell fabrication approaches suitable for future manufacturing demands, and solar cell encapsulation. This year's theme, ''Crystalline Si Solar Cells: Leapfrogging the Barriers,'' reflects the continued success of crystalline Si PV in overcoming technological barriers to improve solar cell performance and lower the cost of Si PV. The workshop will consist of presentations by invited speakers, followed by discussion sessions. In addition, there will be two poster sessions presenting the latest research and development results. Some presentations will address recent technologies in the microelectronics field that may have a direct bearing on PV. The sessions will include: Advances in crystal growth and material issues; Impurities and defects; Dynamics during device processing; Passivation; High-efficiency Si solar cells; Advanced processing; Thin Si solar cells; and Solar cell reliability and module issues.

  10. Emission of blue light from hydrogenated amorphous silicon carbide

    Science.gov (United States)

    Nevin, W. A.; Yamagishi, H.; Yamaguchi, M.; Tawada, Y.

    1994-04-01

    THE development of new electroluminescent materials is of current technological interest for use in flat-screen full-colour displays1. For such applications, amorphous inorganic semiconductors appear particularly promising, in view of the ease with which uniform films with good mechanical and electronic properties can be deposited over large areas2. Luminescence has been reported1 in the red-green part of the spectrum from amorphous silicon carbide prepared from gas-phase mixtures of silane and a carbon-containing species (usually methane or ethylene). But it is not possible to achieve blue luminescence by this approach. Here we show that the use of an aromatic species-xylene-as the source of carbon during deposition results in a form of amorphous silicon carbide that exhibits strong blue luminescence. The underlying structure of this material seems to be an unusual combination of an inorganic silicon carbide lattice with a substantial 'organic' π-conjugated carbon system, the latter dominating the emission properties. Moreover, the material can be readily doped with an electron acceptor in a manner similar to organic semiconductors3, and might therefore find applications as a conductivity- or colour-based chemical sensor.

  11. Device and material characterization and analytic modeling of amorphous silicon thin film transistors

    Science.gov (United States)

    Slade, Holly Claudia

    Hydrogenated amorphous silicon thin film transistors (TFTs) are now well-established as switching elements for a variety of applications in the lucrative electronics market, such as active matrix liquid crystal displays, two-dimensional imagers, and position-sensitive radiation detectors. These applications necessitate the development of accurate characterization and simulation tools. The main goal of this work is the development of a semi- empirical, analytical model for the DC and AC operation of an amorphous silicon TFT for use in a manufacturing facility to improve yield and maintain process control. The model is physically-based, in order that the parameters scale with gate length and can be easily related back to the material and device properties. To accomplish this, extensive experimental data and 2D simulations are used to observe and quantify non- crystalline effects in the TFTs. In particular, due to the disorder in the amorphous network, localized energy states exist throughout the band gap and affect all regimes of TFT operation. These localized states trap most of the free charge, causing a gate-bias-dependent field effect mobility above threshold, a power-law dependence of the current on gate bias below threshold, very low leakage currents, and severe frequency dispersion of the TFT gate capacitance. Additional investigations of TFT instabilities reveal the importance of changes in the density of states and/or back channel conduction due to bias and thermal stress. In the above threshold regime, the model is similar to the crystalline MOSFET model, considering the drift component of free charge. This approach uses the field effect mobility to take into account the trap states and must utilize the correct definition of threshold voltage. In the below threshold regime, the density of deep states is taken into account. The leakage current is modeled empirically, and the parameters are temperature dependent to 150oC. The capacitance of the TFT can be

  12. Corrosion Processes of the CANDU Steam Generator Materials in the Presence of Silicon Compounds

    International Nuclear Information System (INIS)

    Lucan, Dumitra; Fulger, Manuela; Velciu, Lucian; Lucan, Georgiana; Jinescu, Gheorghita

    2006-01-01

    The feedwater that enters the steam generators (SG) under normal operating conditions is extremely pure but, however, it contains low levels (generally in the μg/l concentration range) of impurities such as iron, chloride, sulphate, silicate, etc. When water is converted into steam and exits the steam generator, the non-volatile impurities are left behind. As a result of their concentration, the bulk steam generator water is considerably higher than the one in the feedwater. Nevertheless, the concentrations of corrosive impurities are in general sufficiently low so that the bulk water is not significantly aggressive towards steam generator materials. The impurities and corrosion products existing in the steam generator concentrate in the porous deposits on the steam generator tubesheet. The chemical reactions that take place between the components of concentrated solutions generate an aggressive environment. The presence of this environment and of the tubesheet crevices lead to localized corrosion and thus the same tubes cannot ensure the heat transfer between the fluids of the primary and secondary circuits. Thus, it becomes necessary the understanding of the corrosion process that develops into SG secondary side. The purpose of this paper is the assessment of corrosion behavior of the tubes materials (Incoloy-800) at the normal secondary circuit parameters (temperature = 2600 deg C, pressure = 5.1 MPa). The testing environment was demineralized water containing silicon compounds, at a pH=9.5 regulated with morpholine and cyclohexyl-amine (all volatile treatment - AVT). The paper presents the results of metallographic examinations as well as the results of electrochemical measurements. (authors)

  13. Hydrogenated amorphous silicon radiation detectors: Material parameters; radiation hardness; charge collection

    International Nuclear Information System (INIS)

    Qureshi, S.

    1991-01-01

    Properties of hydrogenated amorphous silicon p-i-n diodes relevant to radiation detection applications were studied. The interest in using this material for radiation detection applications in physics and medicine was motivated by its high radiation hardness and the fact that it can be deposited over large area at relatively low cost. Thick, fully depleted a-Si:H diodes are required for sufficient energy deposition by a charged particle and better signal to noise ratio. A sizeable electric field is essential for charge collection in a -Si:H diodes. The large density of ionized defects that exist in the i layer when the diode is under DC bias causes the electric field to be uniform. Material parameters, namely carrier mobility and lifetime and the ionized defect density in thick a-Si:H p-i-n diodes were studied by the transient photoconductivity method. The increase in diode leakage current with reverse bias over the operating bias was consistent with the Poole-Frenkel effect, involving excitation of carriers from neutral defects. The diode noise over the operating voltage range was completely explained in terms of the shot noise component for CR-(RC) 4 (pseudo-Gaussian) shaping at 3 μs shaping time and the noise component at 0 V bias (delta and thermal noise) added in quadrature. Irradiation with 1 Mev neutrons produced no significant degradation in leakage current and noise at fluences exceeding 4 x 10 14 cm -2 . Irradiation with 1.4 Mev proton fluence of 1 x 10 14 cm -2 decreased carrier lifetime by a factor of ∼4. Degradation in leakage current and noise became significant at proton fluence of ∼10 13 cm -2

  14. Carbon nanotube-coated silicone as a flexible and electrically conductive biomedical material

    International Nuclear Information System (INIS)

    Matsuoka, Makoto; Akasaka, Tsukasa; Totsuka, Yasunori; Watari, Fumio

    2012-01-01

    Artificial cell scaffolds that support cell adhesion, growth, and organization need to be fabricated for various purposes. Recently, there have been increasing reports of cell patterning using electrical fields. We fabricated scaffolds consisting of silicone sheets coated with single-walled (SW) or multi-walled (MW) carbon nanotubes (CNTs) and evaluated their electrical properties and biocompatibility. We also performed cell alignment with dielectrophoresis using CNT-coated sheets as electrodes. Silicone coated with 10 μg/cm 2 SWCNTs exhibited the least sheet resistance (0.8 kΩ/sq); its conductivity was maintained even after 100 stretching cycles. CNT coating also improved cell adhesion and proliferation. When an electric field was applied to the cell suspension introduced on the CNT-coated scaffold, the cells became aligned in a pearl-chain pattern. These results indicate that CNT coating not only provides electro-conductivity but also promotes cell adhesion to the silicone scaffold; cells seeded on the scaffold can be organized using electricity. These findings demonstrate that CNT-coated silicone can be useful as a biocompatible scaffold. - Highlights: ► We fabricated a CNT-coated silicone which has conductivity and biocompatibility. ► The conductivity was maintained after 100 cycles of stretching. ► CNT coatings enabled C2C12 cells adhere to the silicone surface. ► Cells were aligned with dielectrophoresis between CNT-coated silicone surfaces.

  15. Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

    Science.gov (United States)

    Ji, Xiaoyu; Cheng, Hiu Yan; Grede, Alex J.; Molina, Alex; Talreja, Disha; Mohney, Suzanne E.; Giebink, Noel C.; Badding, John V.; Gopalan, Venkatraman

    2018-04-01

    Conformally coating textured, high surface area substrates with high quality semiconductors is challenging. Here, we show that a high pressure chemical vapor deposition process can be employed to conformally coat the individual fibers of several types of flexible fabrics (cotton, carbon, steel) with electronically or optoelectronically active materials. The high pressure (˜30 MPa) significantly increases the deposition rate at low temperatures. As a result, it becomes possible to deposit technologically important hydrogenated amorphous silicon (a-Si:H) from silane by a simple and very practical pyrolysis process without the use of plasma, photochemical, hot-wire, or other forms of activation. By confining gas phase reactions in microscale reactors, we show that the formation of undesired particles is inhibited within the microscale spaces between the individual wires in the fabric structures. Such a conformal coating approach enables the direct fabrication of hydrogenated amorphous silicon-based Schottky junction devices on a stainless steel fabric functioning as a solar fabric.

  16. Report for fiscal 1998 on results of research and development of silicon-based polymeric material. Material research for the liquid methane fueled aircraft engine; 1998 nendo keisokei kobunshi zairyo no kenkyu kaihatsu seika hokokusho. Methane nenryo kokukiyo engine kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Research was conducted for the purpose of establishing basic technology concerning molecular design, synthesis, material formation, and evaluation of silicon-based polymers which are expected to provide superior electronic/optical functions, high heat/combustion resistance and dynamic properties. The research subjects were such as following: research and development of silicon-based polymeric materials with sea-island microstructures; research and development of silicon-based polymeric materials with sea-island microstructures; research and development on IPN formation with silicon-based polymers; research and development of hybrid silicon polymers with organometallic compounds; research and development of silicon containing polymer materials with ring structures; general committee for investigation and research; the optimized low-temperature Wurtz synthesis and modification of polysilanes; study of unsaturated and hypercoordinate organosilicon compounds; basic studies on the synthesis and properties of silicon-based high polymers; studies of new monomer-synthesis and their polymerization reaction; studies on new method of preparation and functionalization of polysilanes; novel applications of silicon-based polymers in imaging devices for information display, memory, and recordings; and molecular design of silicon-containing {pi}-conjugated and {sigma}-conjugated compounds. (NEDO)

  17. Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final Report. Volume II: Silicon material

    OpenAIRE

    Lutwack, R.

    1986-01-01

    The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development. The goal of the Silicon Material Task, a part of the FSA Project, was to develop and ...

  18. Obtaining of polycrystalline silicon for semiconductor industry

    International Nuclear Information System (INIS)

    Mukashev, F.; Nauryzbaev, M.; Kolesnikov, B.; Ivanov, Y.

    1996-01-01

    The purpose of the project is to create pilot equipment and optimize the process of obtaining polycrystalline silicon on semi-industrial level. In the past several decades, the historical experience in the developing countries has shown that one of the most promising ways to improve the economy,of a country is to establish semiconductor industry. First of all, the results can help increase defense, national security and create industrial production. The silane method, which has been traditionally' used for obtaining technical and polycrystalline silicon, is to obtain and then to pyrolyzed mono-and poly silanes. Although the traditional methods of obtaining silicon hydrides have specific advantages, such as utilizing by-products, they also have clear shortcomings, i.e. either low output of the ultimate product ( through hydrolysis of Mg 2 Si) or high contents of by-products in it or high contents of dissolving vapors (through decomposing Mg 2 Si in non-water solutions)

  19. Hyperpolarized Porous Silicon Nanoparticles: Potential Theragnostic Material for ²⁹Si Magnetic Resonance Imaging.

    Science.gov (United States)

    Seo, Hyeonglim; Choi, Ikjang; Whiting, Nicholas; Hu, Jingzhe; Luu, Quy Son; Pudakalakatti, Shivanand; McCowan, Caitlin; Kim, Yaewon; Zacharias, Niki; Lee, Seunghyun; Bhattacharya, Pratip; Lee, Youngbok

    2018-05-20

    Porous silicon nanoparticles have recently garnered attention as potentially-promising biomedical platforms for drug delivery and medical diagnostics. Here, we demonstrate porous silicon nanoparticles as contrast agents for ²⁹Si magnetic resonance imaging. Size-controlled porous silicon nanoparticles were synthesized by magnesiothermic reduction of silica nanoparticles and were surface activated for further functionalization. Particles were hyperpolarized via dynamic nuclear polarization to enhance their ²⁹Si MR signals; the particles demonstrated long ²⁹Si spin-lattice relaxation (T₁) times (~ 25 mins), which suggests potential applicability for medical imaging. Furthermore, ²⁹Si hyperpolarization levels were sufficient to allow ²⁹Si MRI in phantoms. These results underscore the potential of porous silicon nanoparticles that, when combined with hyperpolarized magnetic resonance imaging, can be a powerful theragnostic deep tissue imaging platform to interrogate various biomolecular processes in vivo. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Patterned Array of Poly(ethylene glycol Silane Monolayer for Label-Free Detection of Dengue

    Directory of Open Access Journals (Sweden)

    Nor Zida Rosly

    2016-08-01

    Full Text Available In the present study, the construction of arrays on silicon for naked-eye detection of DNA dengue was demonstrated. The array was created by exposing a polyethylene glycol (PEG silane monolayer to 254 nm ultraviolet (UV light through a photomask. Formation of the PEG silane monolayer and photomodifed surface properties was thoroughly characterized by using atomic force microscopy (AFM, X-ray photoelectron spectroscopy (XPS, and contact angle measurements. The results of XPS confirmed that irradiation of ultraviolet (UV light generates an aldehyde functional group that offers conjugation sites of amino DNA probe for detection of a specific dengue virus target DNA. Employing a gold enhancement process after inducing the electrostatic interaction between positively charged gold nanoparticles and the negatively charged target DNA hybridized to the DNA capture probe allowed to visualize the array with naked eye. The developed arrays demonstrated excellent performance in diagnosis of dengue with a detection limit as low as 10 pM. The selectivity of DNA arrays was also examined using a single base mismatch and noncomplementary target DNA.

  1. Economic assessment of possible electron accelerator applications in curing silicon rubber based electric installation material

    International Nuclear Information System (INIS)

    Rmot, L.

    1976-01-01

    A description is given of the conventional technology of production of conductors with silicon rubber insulation and of the radiation vulcanization method, i.e., the radiation cross-linking of silicon rubber. An economic comparison is shown for both technologies. The analysis shows that the indices for the radiation cross-linking technology are favourable and that the introduction thereof would be advantageous. (J.P.)

  2. Determination of silicon in plant materials by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Paulino Florêncio de [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Centro de Tecnologia Canavieira, PO Box 162, 13400-970 Piracicaba, SP (Brazil); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Prof. Artur Riedel, 275, 09972-270, Diadema, SP (Brazil); Gustinelli Arantes de Carvalho, Gabriel; Nunes, Lidiane Cristina [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Silva Gomes, Marcos da [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP (Brazil); Guerra, Marcelo Braga Bueno [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Krug, Francisco José, E-mail: fjkrug@cena.usp.br [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil)

    2013-05-01

    In spite of the importance of Si for improving the productivity of many important crops, such as those from the Poaceae family (e.g. sugar cane, maize, wheat, rice), its quantitative determination in plants is seldom carried out and restricted to few laboratories in the world. There is a survey of methods in the literature, but most of them are either laborious or difficult to validate in view of the low availability of reference materials with a certified Si mass fraction. The aim of this study is to propose a method for the direct determination of Si in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device. Experiments were carried out with leaves from 24 sugar cane varieties, with mass fractions varying from ca. 2 to 10 g kg{sup −1} Si. Pellets prepared from cryogenically ground leaves were used as test samples for both method development and validation of the calibration model. Best results were obtained when the test samples were interrogated with laser fluence of 50 J cm{sup −2} (750 μm spot size) and measurements carried out at Si I 212.412 nm emission line. The results obtained by LIBS were compared with those from inductively coupled plasma optical emission spectrometry after oven-induced alkaline digestion, and no significant differences were observed after applying the Student's t-test at 95% confidence level. The trueness of the proposed LIBS method was also confirmed from the analysis of CRM GBW 07603 (Bush branches and leaves). - Highlights: • This is the first application of LIBS for determination of Si in plant materials. • Data indicate that the method is appropriate for Si diagnosis in routine analysis. • Silicon can be simultaneously determined with macro- and

  3. Determination of silicon in plant materials by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Souza, Paulino Florêncio de; Santos, Dário; Gustinelli Arantes de Carvalho, Gabriel; Nunes, Lidiane Cristina; Silva Gomes, Marcos da; Guerra, Marcelo Braga Bueno; Krug, Francisco José

    2013-01-01

    In spite of the importance of Si for improving the productivity of many important crops, such as those from the Poaceae family (e.g. sugar cane, maize, wheat, rice), its quantitative determination in plants is seldom carried out and restricted to few laboratories in the world. There is a survey of methods in the literature, but most of them are either laborious or difficult to validate in view of the low availability of reference materials with a certified Si mass fraction. The aim of this study is to propose a method for the direct determination of Si in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device. Experiments were carried out with leaves from 24 sugar cane varieties, with mass fractions varying from ca. 2 to 10 g kg −1 Si. Pellets prepared from cryogenically ground leaves were used as test samples for both method development and validation of the calibration model. Best results were obtained when the test samples were interrogated with laser fluence of 50 J cm −2 (750 μm spot size) and measurements carried out at Si I 212.412 nm emission line. The results obtained by LIBS were compared with those from inductively coupled plasma optical emission spectrometry after oven-induced alkaline digestion, and no significant differences were observed after applying the Student's t-test at 95% confidence level. The trueness of the proposed LIBS method was also confirmed from the analysis of CRM GBW 07603 (Bush branches and leaves). - Highlights: • This is the first application of LIBS for determination of Si in plant materials. • Data indicate that the method is appropriate for Si diagnosis in routine analysis. • Silicon can be simultaneously determined with macro- and micronutrients

  4. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Energy Technology Data Exchange (ETDEWEB)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

    2011-10-29

    Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  5. Silicon anode materials with ultra-low resistivity from the inside out for lithium ion batteries

    Science.gov (United States)

    Xu, Guojun; Jin, Chenxin; Liu, Liekai; Lan, Yu; Yue, Zhihao; Li, Xiaomin; Sun, Fugen; Huang, Haibin; Zhou, Lang

    2017-12-01

    Broken silicon (Si) wafers with electrical resistivity of 1 and 0.001 Ω cm were respectively ball-milled to Si particles with median diameters of less than 1 μm. Both these two types of Si particles were deposited with silver (Ag) nanoparticles by self-selective electroless deposition method. 1-Ω cm-Si particles, 0.001-Ω cm-Si particles, Ag-deposited 1-Ω cm-Si particles and Ag-deposited 0.001-Ω cm-Si particles were, respectively, mixed with graphite particles in weight ratio of 1:9 to form four types of Si-C anode materials and then they were assembled into coin cells. The experimental results indicate that the Ag-deposited 0.001-Ω cm-Si sample shows the higher capacity, better rate and cycle performance than other three samples, due to the high conductivity of Ag-deposited 0.001-Ω cm-Si sample from the inside out. At the current density of 750 mA g-1, the discharge capacity gap of Ag-deposited 0.001-Ω cm-Si sample and 0.001-Ω cm-Si sample is as high as 141.7 mA h g-1, which is almost equal to the discharge capacity of the latter. Besides, the discharge capacity retention ratio of Ag-deposited 0.001-Ω cm-Si sample after 50 cycles is 70%, which is 23.5% higher than that of 0.001-Ω cm-Si sample.

  6. Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants.

    Science.gov (United States)

    Gryshkov, Oleksandr; Klyui, Nickolai I; Temchenko, Volodymyr P; Kyselov, Vitalii S; Chatterjee, Anamika; Belyaev, Alexander E; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

    2016-11-01

    Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO2) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Fiscal 2000 achievement report. Development of energy use rationalization-oriented silicon manufacturing process (Survey and study of analysis of commercialization of solar-grade silicon material manufacturing technology); 2000 nendo shin energy sangyo gijutsu sogo kaihatsu kiko kyodo kenkyu gyomu seika hokokusho. Energy shiyo gorika silicon seizo process kaihatsu (Taiyodenchiyou silicon genryo seizo gijutsu no jitsuyoka kaiseki ni kansuru chosa kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The trend of technology development, problems harbored therein, trend of the market, and the like were investigated for supporting the development of technologies for the mass production and commercialization of solar-grade silicon materials. Concerning the future of production enhancement and cost reduction in the manufacture of polycrystalline silicon solar cells, studies were made from the technological viewpoint. The results are shown below. It is estimated that approximately 4,500 tons of material silicon will be necessary in 2005 and 6,500-10,700 tons in 2010. Since the melting purification method of NEDO (New Energy and Industrial Technology Development Organization) now under development step by step toward commercialization as well as the conventional source will provide the necessary amount of material silicon, it is inferred that the development of solar cells will go on without any restraint originating in the semiconductor industry. With the commercialization of the technologies so far developed and the development/commercialization of the fast-acting high-performance solar cell technology, probabilities are high that the polycrystalline silicon solar cell manufacturing cost in 2010 will be as low as to be on the 100 yen/W (93-118 yen/W) level which is the level now held up as the goal. (NEDO)

  8. Athermal silicon optical add-drop multiplexers based on thermo-optic coefficient tuning of sol-gel material.

    Science.gov (United States)

    Namnabat, Soha; Kim, Kyung-Jo; Jones, Adam; Himmelhuber, Roland; DeRose, Christopher T; Trotter, Douglas C; Starbuck, Andrew L; Pomerene, Andrew; Lentine, Anthony L; Norwood, Robert A

    2017-09-04

    Silicon photonics has gained interest for its potential to provide higher efficiency, bandwidth and reduced power consumption compared to electrical interconnects in datacenters and high performance computing environments. However, it is well known that silicon photonic devices suffer from temperature fluctuations due to silicon's high thermo-optic coefficient and therefore, temperature control in many applications is required. Here we present an athermal optical add-drop multiplexer fabricated from ring resonators. We used a sol-gel inorganic-organic hybrid material as an alternative to previously used materials such as polymers and titanium dioxide. In this work we studied the thermal curing parameters of the sol-gel and their effect on thermal wavelength shift of the rings. With this method, we were able to demonstrate a thermal shift down to -6.8 pm/°C for transverse electric (TE) polarization in ring resonators with waveguide widths of 325 nm when the sol-gel was cured at 130°C for 10.5 hours. We also achieved thermal shifts below 1 pm/°C for transverse magnetic (TM) polarization in the C band under different curing conditions. Curing time compared to curing temperature shows to be the most important factor to control sol-gel's thermo-optic value in order to obtain an athermal device in a wide temperature range.

  9. Collision processes of hydrocarbon species in hydrogen plasmas. Pt. 3. The Silane-family

    CERN Document Server

    Janev, R K

    2003-01-01

    Cross sections are provided for most important collision processes of the Silicon-Hydrides from the ''Silane-family'': SiH sub y (y = 1 - 4) molecules and their ions SiH sub y sup + , with (plasma) electrons and protons. The processes include: electron impact ionization and dissociation of SiH sub y , dissociative excitation, ionization and recombination of SiH sub y sup + ions with electrons, and charge - and atom - exchange in proton collisions with SiH sub y. All important channels of dissociative processes are considered. Information is also provided on the energetics (reactants/products energy loss / gain) of each individual reaction channel. Total and partial cross sections are presented in compact analytic forms. The critical assessment of data, derivation of new data and presentation of results follow closely the concepts of the recently published related databases for Carbon-Hydrides, namely for the Methane family, and for the Ethane- and the Propane families, respectively.

  10. Ionization measurement as a function of the electric field in tetramethyl-silane (TMS)

    International Nuclear Information System (INIS)

    Daba, A.G.

    1992-07-01

    The WALIC collaboration has built a calorimeter prototype using the tetramethyl-pentane (TMP) as active medium and lead as absorber medium in order to study the response of electrons and hadrons. The aim of this work is to study the response of tetramethyl-silane to high electric fields knowing that TMP and TMS have similar properties and similar behaviour with electric field. A test bench is mounted to measure the charge deposited by electrons emitted by a ruthenium source. The trigger was made using a silicon detector. Low noise amplifiers were designed and built for the signal conditioning and in order to reduce the pick-up noise, the system is completely isolated in a double Faraday cage. A theoretical study of noise has been developed. The signal allowed to study the behaviour of warm liquid in presence of a high electric field

  11. Synthesis and characterization of hybrid silicon based complexing materials: extraction of transuranic elements from high level liquid waste; Synthese et caracterisation de gels hybrides de silice a proprietes complexantes: applications a l'extraction des transuraniens des effluents aqueux

    Energy Technology Data Exchange (ETDEWEB)

    Conocar, O

    1999-07-01

    Hybrid organic/inorganic silica compounds with extractive properties have been developed under an enhanced decontamination program for radioactive aqueous nitric acid waste in nuclear facilities. The materials were obtained by the sol-gel process through hydrolysis and poly-condensation of complexing organo-tri-alkoxy-silanes with the corresponding tetra-alkoxy-silane. Hybrid silica compounds were initially synthesized and characterized from mono- and bis-silyl precursors with malonamide or ethylenediamine patterns. Solids with different specific areas and pore diameters were obtained depending on the nature of the precursor, its functionality and its concentration in the tetra-alkoxy-silane. These compounds were then considered and assessed for use in plutonium and americium extraction. Excellent results-partitioning coefficients and capacities have been obtained with malonamide hybrid silica. The comparison with silica compounds impregnated or grafted with the same type of organic group is significant in this respect. Much of the improved performance obtained with hybrid silica may be attributed to the large quantity of complexing groups that can be incorporated in these materials. The effect of the solid texture on the extraction performance was also studied. Although the capacity increased with the specific area, little effect was observed on the distribution coefficients -notably for americium- indicating that the most favorable complexation sites are found on the outer surface. Macroporous malonamide hybrid silica compounds were synthesized to study the effects of the pore diameter, but the results have been inconclusive to date because of the unexpected molecular composition of the materials. (author)

  12. Low cost solar array project cell and module formation research area: Process research of non-CZ silicon material

    Science.gov (United States)

    1981-01-01

    Liquid diffusion masks and liquid applied dopants to replace the CVD Silox masking and gaseous diffusion operations specified for forming junctions in the Westinghouse baseline process sequence for producing solar cells from dendritic web silicon were investigated. The baseline diffusion masking and drive processes were compared with those involving direct liquid applications to the dendritic web silicon strips. Attempts were made to control the number of variables by subjecting dendritic web strips cut from a single web crystal to both types of operations. Data generated reinforced earlier conclusions that efficiency levels at least as high as those achieved with the baseline back junction formation process can be achieved using liquid diffusion masks and liquid dopants. The deliveries of dendritic web sheet material and solar cells specified by the current contract were made as scheduled.

  13. Time-resolved measurements of highly-polymerised negative ions in rf silane plasma deposition experiments

    International Nuclear Information System (INIS)

    Howling, A.A.; Sansonnens, L.; Dorier, J.L.; Hollenstein, C.

    1993-07-01

    The time-resolved fluxes of negative polysilicon hydride ions from a power-modulated rf silane plasma have been measured by quadrupole mass spectrometry and modeled using a simple polymerisation scheme. Experiments were performed with plasma parameters suitable for high-quality amorphous silicon deposition. Polysilicon hydride anions diffuse from the plasma with low energy (approximately 0.5 eV) during the afterglow after the electron density has decayed and the sheath fields have collapsed. The mass-dependence of the temporal behavior of the anion loss flux demonstrates that the plasma composition is influenced by the modulation frequency. The negative species attain much higher masses than the positive or neutral species, and anions containing as many as sixteen silicon atoms have been observed, corresponding to the 500 amu limit of the mass spectrometer. This suggests that negative ions could be the precursors to particle formation. Ion-molecule and ion-ion reactions are discussed and a simple negative ion polymerisation scheme is proposed which qualitatively reproduces the experimental results. The model shows that the densities of high mass negative ions in the plasma are strongly reduced by modulation frequencies near 1 kHz. Each plasma period is then too short for the polymerisation chain to propagate to high masses before the elementary anions are lost in each subsequent afterglow period. This explains why modulation of the rf power can reduce particle contamination. We conclude that, for the case of silane rf plasmas, the initiation steps which ultimately lead to particle contamination proceed by negative ion polymerisation. (author) 15 figs., 72 refs

  14. Substrate temperature dependence of microcrystallinity in plasma-deposited, boron-doped hydrogenated silicon alloys

    International Nuclear Information System (INIS)

    Rajeswaran, G.; Kampas, F.J.; Vanier, P.E.; Sabatini, R.L.; Tafto, J.

    1983-01-01

    The glow-discharge decomposition of silane diluted in hydrogen using diborane as a dopant results in the deposition of p-type microcrystalline silicon films at relatively low temperatures. The conductivity of these films is critically dependent on the substrate temperature when the ratio of silane flow rate to total gas flow rate is 1%. Electron micrographs show that highly conducting films contain numerous clusters of 2.5-nm crystallites that are embedded in an amorphous medium

  15. Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants

    Energy Technology Data Exchange (ETDEWEB)

    Gryshkov, Oleksandr, E-mail: gryshkov@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany); Klyui, Nickolai I., E-mail: klyuini@ukr.net [College of Physics, Jilin University, 130012 Changchun (China); V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Temchenko, Volodymyr P., E-mail: tvp@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Kyselov, Vitalii S., E-mail: kyselov@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Chatterjee, Anamika, E-mail: chatterjee@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany); Belyaev, Alexander E., E-mail: belyaev@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Lauterboeck, Lothar, E-mail: lauterboeck@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany); Iarmolenko, Dmytro, E-mail: iarmolenko.dmytro@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Glasmacher, Birgit, E-mail: glasmacher@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany)

    2016-11-01

    Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO{sub 2}) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO{sub 2} using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO{sub 2} to the initial HA powder resulted in significant decomposition of the final HA/ZrO{sub 2} coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO{sub 2} coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. - Highlights: • Synthesis and characterization of porous biomorphic SiC ceramics derived from wood • Successful deposition of bioactive calcium phosphate coatings using gas detonation deposition • Porosity and pore size of Si

  16. Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants

    International Nuclear Information System (INIS)

    Gryshkov, Oleksandr; Klyui, Nickolai I.; Temchenko, Volodymyr P.; Kyselov, Vitalii S.; Chatterjee, Anamika; Belyaev, Alexander E.; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

    2016-01-01

    Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO 2 ) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO 2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO 2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO 2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO 2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. - Highlights: • Synthesis and characterization of porous biomorphic SiC ceramics derived from wood • Successful deposition of bioactive calcium phosphate coatings using gas detonation deposition • Porosity and pore size of SiC ceramics depend on wood

  17. Achievement report for fiscal 1999 on the development of silicon manufacturing process rationalizing energy utilization. Research and study on analysis to put silicon raw material manufacturing technology for solar cells into practical use; 1999 nendo energy shiyo gorika silicon seizo process kaihatsu seika hokokusho. Taiyo denchi silicon genryo seizo gijutsu no jitsuyoka kaiseki ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    In order to support the development and practical application of a mass production technology for manufacturing silicon raw materials for solar cells, research and study were performed on trends of developing the related technologies, and movements in markets and industries. This paper reports the achievements thereof in fiscal 1999. Markets for solar cells are growing favorably, and the worldwide solar cell production in 1999 was 200 MWp, of which 80% or more is occupied by crystalline silicon solar cell. While development of the manufacturing technology for SOG-Si mass-production is in the stage of operation research of pilot plants, it has been verified that problems of impurity contamination was resolved, and high-purity silicon can be manufactured. In developing the silicon scrap utilization technology and a technology to integrate silicon refinement with casting, a conversion efficiency of 14% or higher was acquired in prototype sample substrates. It has been verified that a variety of raw materials can be dealt with by using the above technology, which has a possibility of cost reduction. In developing a substrate manufacturing technology, a great progress has been made in enhancing the productivity and reducing the cost by developing the continuous casting in the electromagnetic casting and the automation technology. (NEDO)

  18. Effects of silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets

    Directory of Open Access Journals (Sweden)

    Saadet Atsü

    2011-06-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effects of tribochemical silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets. MATERIAL AND METHODS: Twenty debonded metal and 20 debonded ceramic brackets were randomly assigned to receive one of the following surface treatments (n=10 for each group: (1 sandblasting (control; (2 tribochemical silica coating combined with silane. Brackets were rebonded to the enamel surface on the labial and lingual sides of premolars with a light-polymerized resin composite. All specimens were stored in distilled water for 1 week and then thermocycled (5,000 cycles between 5-55ºC. Shear bond strength values were measured using a universal testing machine. Student's t-test was used to compare the data (α=0.05. Failure mode was assessed using a stereomicroscope, and the treated and non-treated bracket surfaces were observed by scanning electron microscopy. RESULTS: Rebonded ceramic brackets treated with silica coating followed by silanization had significantly greater bond strength values (17.7±4.4 MPa than the sandblasting group (2.4±0.8 MPa, P<0.001. No significant difference was observed between the rebonded metal brackets treated with silica coating with silanization (15±3.9 MPa and the sandblasted brackets (13.6±3.9 MPa. Treated rebonded ceramic specimens primarily exhibited cohesive failure in resin and adhesive failure at the enamel-adhesive interface. CONCLUSIONS: In comparison to sandblasting, silica coating with aluminum trioxide particles followed by silanization resulted in higher bond strengths of rebonded ceramic brackets.

  19. Low-temperature radiation damage in silicon - 1: Annealing studies on N-type material

    International Nuclear Information System (INIS)

    Awadelkarim, O.O.

    1986-07-01

    The presence of electrically active defects in electron-irradiated P-doped n-type silicon was monitored using capacitance and loss factor measurements. Irradiations were performed at temperatures c - 0.14) eV and (E c - 0.24) eV in the gap are ascribed to the carbon interstitial and the divacancy, respectively. (author)

  20. Silicone-based composite materials simulate breast tissue to be used as ultrasonography training phantoms.

    Science.gov (United States)

    Ustbas, Burcin; Kilic, Deniz; Bozkurt, Ayhan; Aribal, Mustafa Erkin; Akbulut, Ozge

    2018-03-02

    A silicone-based composite breast phantom is fabricated to be used as an education model in ultrasonography training. A matrix of silicone formulations is tracked to mimic the ultrasonography and tactile response of human breast tissue. The performance of two different additives: (i) silicone oil and (ii) vinyl-terminated poly (dimethylsiloxane) (PDMS) are monitored by a home-made acoustic setup. Through the use of 75 wt% vinyl-terminated PDMS in two-component silicone elastomer mixture, a sound velocity of 1.29 ± 0.09 × 10 3  m/s and an attenuation coefficient of 12.99 ± 0.08 dB/cm-values those match closely to the human breast tissue-are measured with 5 MHz probe. This model can also be used for needle biopsy as well as for self-exam trainings. Herein, we highlight the fabrication of a realistic, durable, accessible, and cost-effective training platform that contains skin layer, inner breast tissue, and tumor masses. Copyright © 2018. Published by Elsevier B.V.

  1. Materials and Light Management for High-Efficiency Thin-Film Silicon Solar Cells

    NARCIS (Netherlands)

    Tan, H.

    2015-01-01

    Direct conversion of sunlight into electricity is one of the most promising approaches to provide sufficient renewable energy for humankind. Solar cells are such devices which can efficiently generate electricity from sunlight through the photovoltaic effect. Thin-film silicon solar cells, a type of

  2. Silicon doped InP as an alternative plasmonic material for mid-infrared

    DEFF Research Database (Denmark)

    Panah, Mohammad Esmail Aryaee; Han, Li; Christensen, Dennis Valbjørn

    2016-01-01

    Silicon-doped InP is grown on top of semiinsulating iron-doped and sulfur-doped InP substrates by metalorganic vapor phase epitaxy (MOVPE), and the growth parameters are adjusted to obtain various free carrier concentrations from 1.05×1019 cm-3 up to 3.28×1019 cm-3. Midinfrared (IR) reflection...

  3. Synthesis and Characterization of Silicon Nanoparticles Inserted into Graphene Sheets as High Performance Anode Material for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2014-01-01

    Full Text Available Silicon nanoparticles have been successfully inserted into graphene sheets via a novel method combining freeze-drying and thermal reduction. The structure, electrochemical performance, and cycling stability of this anode material were characterized by SEM, X-ray diffraction (XRD, charge/discharge cycling, and cyclic voltammetry (CV. CV showed that the Si/graphene nanocomposite exhibits remarkably enhanced cycling performance and rate performance compared with bare Si nanoparticles for lithium ion batteries. XRD and SEM showed that silicon nanoparticles inserted into graphene sheets were homogeneous and had better layered structure than the bare silicon nanoparticles. Graphene sheets improved high rate discharge capacity and long cycle-life performance. The initial capacity of the Si nanoparticles/graphene keeps above 850 mAhg−1 after 100 cycles at a rate of 100 mAg−1. The excellent cycle performances are caused by the good structure of the composites, which ensured uniform electronic conducting sheet and intensified the cohesion force of binder and collector, respectively.

  4. Preparation and characterization of flake graphite/silicon/carbon spherical composite as anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Lai Jun; Guo Huajun; Wang Zhixing; Li Xinhai; Zhang Xiaoping; Wu Feixiang; Yue Peng

    2012-01-01

    Highlights: ► Flake graphite/silicon/carbon composite is synthesized via spray drying. ► Flake graphite of ∼0.5 μm and glucose are used to prepare the composite. ► The as-prepared composite shows spherical and porous appearance. ► The composite shows nearly the same cycleability as commercial graphite in 20 cycles. ► The composite shows a reversible capacity of 552 mAh/g at the 20th cycle. - Abstract: Using nano-Si, glucose and flake graphite of ∼0.5 μm as raw materials, flake graphite/silicon/carbon composite is successfully synthesized via spray drying and subsequent pyrolysis. The samples are characterized by XRD, SEM, TEM and electrochemical measurements. The composite is composed of flake graphite, nano-Si and amorphous glucose-pyrolyzed carbon and presents good spherical appearance. Some micron pores arising from the decomposition of glucose exist on the surface of the composite particles. The composite has a high reversible capacity of 602.7 mAh/g with an initial coulombic efficiency of 69.71%, and shows nearly the same cycleability as the commercial graphite in 20 cycles. Both the glucose-pyrolyzed carbon and the micron pores play important roles in improving the cycleability of the composite. The flake graphite/silicon/carbon composite electrode is a potential alternative to graphite for high energy-density lithium ion batteries.

  5. Dependence of the absorption of pulsed CO2-laser radiation by silane on wavenumber, fluence, pulse duration, temperature, optical path length, and pressure of absorbing and nonabsorbing gases

    International Nuclear Information System (INIS)

    Blazejowski, J.; Gruzdiewa, L.; Rulewski, J.; Lampe, F.W.

    1995-01-01

    The absorption of three lines [P(20), 944.2 cm -1 ; P(14), 949.2 cm -1 ; and R(24), 978.5 cm -1 ] of the pulsed CO 2 laser (00 0 1--10 0 0 transition) by SiH 4 was measured at various pulse energy, pulse duration, temperature, optical path length, and pressure of the compound and nonabsorbing foreign gases. In addition, low intensity infrared absorption spectrum of silane was compared with high intensity absorption characteristics for all lines of the pulsed CO 2 laser. The experimental dependencies show deviations from the phenomenological Beer--Lambert law which can be considered as arising from the high intensity of an incident radiation and collisions of absorbing molecules with surroundings. These effects were included into the expression, being an extended form of the Beer--Lambert law, which reasonably approximates all experimental data. The results, except for extending knowledge on the interaction of a high power laser radiation with matter, can help understanding and planning processes leading to preparation of silicon-containing technologically important materials

  6. Hydrogen concentration profiles and chemical bonding in silicon nitride

    International Nuclear Information System (INIS)

    Peercy, P.S.; Stein, H.J.; Doyle, B.L.; Picraux, S.T.

    1978-01-01

    The complementary technique of nuclear reaction analysis and infrared absorption were used to study the concentration profile and chemical bonding of hydrogen in silicon nitride for different preparation and annealing conditions. Silicon nitride prepared by chemical vapor deposition from ammonia-silane mixtures is shown to have hydrogen concentrations of 8.1 and 6.5 at.% for deposition temperatures of 750 and 900 0 C, respectively. Plasma deposition at 300 0 C from these gases results in hydrogen concentrations of approximately 22 at.%. Comparison of nuclear reaction analysis and infrared absorption measurements after isothermal annealing shows that all of the hydrogen retained in the films remains bonded to either silicon or nitrogen and that hydrogen release from the material on annealing is governed by various trap energies involving at least two N-H and one Si-H trap. Reasonable estimates of the hydrogen release rates can be made from the effective diffusion coefficient obtained from measurements of hydrogen migration in hydrogen implanted and annealed films

  7. PREFACE: E-MRS 2012 Spring Meeting, Symposium M: More than Moore: Novel materials approaches for functionalized Silicon based Microelectronics

    Science.gov (United States)

    Wenger, Christian; Fompeyrine, Jean; Vallée, Christophe; Locquet, Jean-Pierre

    2012-12-01

    More than Moore explores a new area of Silicon based microelectronics, which reaches beyond the boundaries of conventional semiconductor applications. Creating new functionality to semiconductor circuits, More than Moore focuses on motivating new technological possibilities. In the past decades, the main stream of microelectronics progresses was mainly powered by Moore's law, with two focused development arenas, namely, IC miniaturization down to nano scale, and SoC based system integration. While the microelectronics community continues to invent new solutions around the world to keep Moore's law alive, there is increasing momentum for the development of 'More than Moore' technologies which are based on silicon technologies but do not simply scale with Moore's law. Typical examples are RF, Power/HV, Passives, Sensor/Actuator/MEMS or Bio-chips. The More than Moore strategy is driven by the increasing social needs for high level heterogeneous system integration including non-digital functions, the necessity to speed up innovative product creation and to broaden the product portfolio of wafer fabs, and the limiting cost and time factors of advanced SoC development. It is believed that More than Moore will add value to society on top of and beyond advanced CMOS with fast increasing marketing potentials. Important key challenges for the realization of the 'More than Moore' strategy are: perspective materials for future THz devices materials systems for embedded sensors and actuators perspective materials for epitaxial approaches material systems for embedded innovative memory technologies development of new materials with customized characteristics The Hot topics covered by the symposium M (More than Moore: Novel materials approaches for functionalized Silicon based Microelectronics) at E-MRS 2012 Spring Meeting, 14-18 May 2012 have been: development of functional ceramics thin films New dielectric materials for advanced microelectronics bio- and CMOS compatible

  8. Silane pre-treatments on copper and aluminium

    International Nuclear Information System (INIS)

    Deflorian, F.; Rossi, S.; Fedrizzi, L.

    2006-01-01

    A large part of aluminium products are coated with an organic layer in order to improve the corrosion resistance. Copper surfaces are also sometimes protected with an organic coating to improve the durability or the aesthetic properties. Examples of industrial applications are household appliances and heat exchanger components. For these applications it is not rare to have the industrial need to treat at the same time components made of aluminium and copper. In order to extend the service life of the organic coated copper a specific surface pre-treatment is often required. Nevertheless, probably because of the limited market of this application, no specific pre-treatments for copper are industrially developed, with the exception of cleaning procedures, but simply extensions of existing pre-treatments optimised for other metals (aluminium, zinc) are used. The application of silane pre-treatments as adhesion promoters for organic coated metals is remarkably increasing in the last decade, because silanes offer very good performance together with high environmental compatibility. The idea is therefore to try to develop a specific silane based pre-treatment for copper. The starting point is the existing silane products for aluminium, optimising the composition and the application conditions (concentration, temperature, pH of the bath, etc.) in order to develop a high performance copper alloy pre-treatment increasing the protective properties and the adhesion of a successively applied organic coating. Moreover these pre-treatments could be used for aluminium alloys too and therefore could be suggested for multi-metals components. The deposits were analysed using FTIR spectroscopy and optical and electron microscopic observations. A careful electrochemical characterisation, mainly by electrochemical impedance spectroscopy measurements (EIS) was carried out to highlight the presence of silane and to evaluate the performance of the different deposits. In order to study an

  9. Towards Cost-Effective Crystalline Silicon Based Flexible Solar Cells: Integration Strategy by Rational Design of Materials, Process, and Devices

    KAUST Repository

    Bahabry, Rabab R.

    2017-11-30

    The solar cells market has an annual growth of more than 30 percent over the past 15 years. At the same time, the cost of the solar modules diminished to meet both of the rapid global demand and the technological improvements. In particular for the crystalline silicon solar cells, the workhorse of this technology. The objective of this doctoral thesis is enhancing the efficiency of c-Si solar cells while exploring the cost reduction via innovative techniques. Contact metallization and ultra-flexible wafer based c-Si solar cells are the main areas under investigation. First, Silicon-based solar cells typically utilize screen printed Silver (Ag) metal contacts which affect the optimal electrical performance. To date, metal silicide-based ohmic contacts are occasionally used for the front contact grid lines. In this work, investigation of the microstructure and the electrical characteristics of nickel monosilicide (NiSi) ohmic contacts on the rear side of c-Si solar cells has been carried out. Significant enhancement in the fill factor leading to increasing the total power conversion efficiency is observed. Second, advanced classes of modern application require a new generation of versatile solar cells showcasing extreme mechanical resilience. However, silicon is a brittle material with a fracture strains <1%. Highly flexible Si-based solar cells are available in the form thin films which seem to be disadvantageous over thick Si solar cells due to the reduction of the optical absorption with less active Si material. Here, a complementary metal oxide semiconductor (CMOS) technology based integration strategy is designed where corrugation architecture to enable an ultra-flexible solar cell module from bulk mono-crystalline silicon solar wafer with 17% efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness and achieves flexibility via interdigitated back contacts. These cells

  10. First-principles studies of a photovoltaic material based on silicon heavily codoped with sulfur and nitrogen

    Science.gov (United States)

    Dong, Xiao; Wang, Yongyong; Song, Xiaohui; Yang, Feng

    2018-03-01

    In silicon co-hyperdoped with nitrogen and sulfur, dopant atoms tend to form dimers in the near-equilibrium process. The dimer that contains substitutional N and S atoms has the lowest formation energy and can form an impurity band that overlaps with the conduction band (CB). When separating the two atoms far apart from each other, the impurity band is clearly isolated from the CB and becomes an intermediate band (IB). The sub-band-gap absorption decreases with the decrease in the substitutional atom distance. The sub-band-gap absorption of the material is the combined effect of the configurations with different N-S distances.

  11. Material synthesis for silicon integrated-circuit applications using ion implantation

    Science.gov (United States)

    Lu, Xiang

    As devices scale down into deep sub-microns, the investment cost and complexity to develop more sophisticated device technologies have increased substantially. There are some alternative potential technologies, such as silicon-on-insulator (SOI) and SiGe alloys, that can help sustain this staggering IC technology growth at a lower cost. Surface SiGe and SiGeC alloys with germanium peak composition up to 16 atomic percent are formed using high-dose ion implantation and subsequent solid phase epitaxial growth. RBS channeling spectra and cross-sectional TEM studies show that high quality SiGe and SiGeC crystals with 8 atomic percent germanium concentration are formed at the silicon surface. Extended defects are formed in SiGe and SiGeC with 16 atomic percent germanium concentration. X-ray diffraction experiments confirm that carbon reduces the lattice strain in SiGe alloys but without significant crystal quality improvement as detected by RBS channeling spectra and XTEM observations. Separation by plasma implantation of oxygen (SPIMOX) is an economical method for SOI wafer fabrication. This process employs plasma immersion ion implantation (PIII) for the implantation of oxygen ions. The implantation rate for Pm is considerably higher than that of conventional implantation. The feasibility of SPIMOX has been demonstrated with successful fabrication of SOI structures implementing this process. Secondary ion mass spectrometry (SIMS) analysis and cross-sectional transmission electron microscopy (XTEM) micrographs of the SPIMOX sample show continuous buried oxide under single crystal overlayer with sharp silicon/oxide interfaces. The operational phase space of implantation condition, oxygen dose and annealing requirement has been identified. Physical mechanisms of hydrogen induced silicon surface layer cleavage have been investigated using a combination of microscopy and hydrogen profiling techniques. The evolution of the silicon cleavage phenomenon is recorded by a series

  12. Porous silicon carbide and aluminum oxide with unidirectional open porosity as model target materials for radioisotope beam production

    Energy Technology Data Exchange (ETDEWEB)

    Czapski, M., E-mail: michal.czapski@cern.ch [CERN, Genève 23 CH-1211 (Switzerland); Stora, T. [CERN, Genève 23 CH-1211 (Switzerland); Tardivat, C.; Deville, S. [Lab. de Synthèse et Fonctionnalisation des Céramiques, CNRS/Saint-Gobain, Av. Jauffret 84306 Cavaillon (France); Santos Augusto, R. [CERN, Genève 23 CH-1211 (Switzerland); Leloup, J.; Bouville, F. [Lab. de Synthèse et Fonctionnalisation des Céramiques, CNRS/Saint-Gobain, Av. Jauffret 84306 Cavaillon (France); Fernandes Luis, R. [Univ. Técnica de Lisboa Estrada Nacional 10, 2686-953 Sacavem, Loures (Portugal)

    2013-12-15

    Highlights: • SiC and Al{sub 2}O{sub 3} of uniaxial porosity were produced with ice-templating method. • The method allows controlled pore formation within the material. • Calculation of mechanical integrity under irradiation with protons was performed. • Generated thermal stresses should not exceed material’s strength. -- Abstract: New silicon carbide (SiC) and aluminum oxide (Al{sub 2}O{sub 3}) of a tailor-made microstructure were produced using the ice-templating technique, which permits controlled pore formation conditions within the material. These prototypes will serve to verify aging of the new advanced target materials under irradiation with proton beams. Before this, the evaluation of their mechanical integrity was made based on the energy deposition spectra produced by FLUKA codes.

  13. Oxide-Free Bonding of III-V-Based Material on Silicon and Nano-Structuration of the Hybrid Waveguide for Advanced Optical Functions

    Directory of Open Access Journals (Sweden)

    Konstantinos Pantzas

    2015-10-01

    Full Text Available Oxide-free bonding of III-V-based materials for integrated optics is demonstrated on both planar Silicon (Si surfaces and nanostructured ones, using Silicon on Isolator (SOI or Si substrates. The hybrid interface is characterized electrically and mechanically. A hybrid InP-on-SOI waveguide, including a bi-periodic nano structuration of the silicon guiding layer is demonstrated to provide wavelength selective transmission. Such an oxide-free interface associated with the nanostructured design of the guiding geometry has great potential for both electrical and optical operation of improved hybrid devices.

  14. Development and Evaluation of Die Materials for Use in the Growth of Silicon Ribbons by the Inverted Ribbon Growth Process. Task 2: LSSA Project

    Science.gov (United States)

    Duffy, M. T.; Berkman, S.; Moss, H. I.; Cullen, G. W.

    1978-01-01

    Several ribbon growth experiments were performed from V-shaped dies coated with CVD Si3N4. The most significant result was the ability to perform five consecutive growth runs from the same die without mechanical degradation of the die through temperature cycling. The die was made from vitreous carbon coated with CVD Si3N4. Silicon oxynitride, Si2N2O, was examined with respect to thermal stability in contact with molten silicon. The results of X-ray analysis indicate that this material is converted to both alpha - and beta-Si3N4 in the presence of molten silicon. Experiments on the stability of CVD SiOxNy shoe that this material can be maintained in contact with molten silicon (sessile drop test) for greater than 30 h at 1450 C without total decompositon. These layers are converted mainly to beta-Si3N4.

  15. Preparation and characterisation of mixed silicon oxycarbide materials; Preparacion y caracterizacion de materiales de oxicarburo de silicio mixtos

    Energy Technology Data Exchange (ETDEWEB)

    Tellez, L.; Tamayo, A.; Mazo, M. A.; Rubio, F.; Rubio, J.

    2010-07-01

    In this work different mixed Silicon oxicarbide materials have been prepared. Si, Si-Ti, Si-Zr and Si-Al oxicarbide materials have been obtained from pyrolisis at 1000 degree centigrade and 1300 degree centigrade of the respective preceramic materials. After pyrolisis X, D and T units of the oxycarbide structure have been observed in such materials. They show the presence of Si-C and Si-O bonds in a given material. The characterization has been carried out by means of FT-IR, Raman NMR {sup 2}9Si, NMR {sup 1}3C and XRD. The formation of Si-Ti, Si-Zr and Si-Al bonds has been estimated in accordance with the decrease of the Si-O-Si wave number observed in the FT-IR spectra. Si and Si-Ti oxycarbide materials do not lead to crystallisation after pyrolisis at highest temperatures, however for Si-Zr and Si-Al oxycarbide materials different crystalline phases have been observed. All pyrolised materials present free and carbidic carbon. After pyrolisis at 1300 degree centigrade the free carbon reacts with Si-O bonds to form SiC{sub 4} groups which must be assigned to nucleus of the {beta}-SiC crystals. (Author)

  16. Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

    International Nuclear Information System (INIS)

    Yasar-Inceoglu, Ozgul; Mangolini, Lorenzo; Zhong, Lanlan

    2015-01-01

    Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3–4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented. (paper)

  17. Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

    Science.gov (United States)

    Yasar-Inceoglu, Ozgul; Zhong, Lanlan; Mangolini, Lorenzo

    2015-08-01

    Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3-4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented.

  18. Report for fiscal 1998 on results of research and development of silicon-based polymeric material; 1998 nendo keisokei kobunshi zairyo no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The research and development of 'silicon-based polymeric materials' has been implemented under ten year plan since 1991 by the research and development system for industrial science and technology, with the following subjects conducted in the general accounting section of fiscal 1998. In the research and development of the synthetic technology of electrically conductive silicon-based polymeric materials, a synthetic method was established for unsaturated side-chain group polysilanes as a basic structural unit for structuring multidimensions. In the research and development of the synthetic technology of new silicon-based polymeric materials capable of plotting circuits, network-shaped polysilanes with various amino groups introduced were synthesized, for which electrical conductivity and temperature dependency were measured. In the research and development of new silicon-based polymeric materials with an electro-luminous function and the like, polymeric synthesis began developing smoothly that has hole-transporting and electron transporting properties concerning the electro-luminous function. In the research and development of silicon-based photoelectric conversion materials, examination was made on the improvement of photoelectric conversion performance by materialization technology including lamination and mixture. The general investigation and research committee contrived further advancement of the research and development. (NEDO)

  19. Photoluminescent silicon nanocrystals with chlorosilane surfaces - synthesis and reactivity

    Science.gov (United States)

    Höhlein, Ignaz M. D.; Kehrle, Julian; Purkait, Tapas K.; Veinot, Jonathan G. C.; Rieger, Bernhard

    2014-12-01

    We present a new efficient two-step method to covalently functionalize hydride terminated silicon nanocrystals with nucleophiles. First a reactive chlorosilane layer was formed via diazonium salt initiated hydrosilylation of chlorodimethyl(vinyl)silane which was then reacted with alcohols, silanols and organolithium reagents. With organolithium compounds a side reaction is observed in which a direct functionalization of the silicon surface takes place.We present a new efficient two-step method to covalently functionalize hydride terminated silicon nanocrystals with nucleophiles. First a reactive chlorosilane layer was formed via diazonium salt initiated hydrosilylation of chlorodimethyl(vinyl)silane which was then reacted with alcohols, silanols and organolithium reagents. With organolithium compounds a side reaction is observed in which a direct functionalization of the silicon surface takes place. Electronic supplementary information (ESI) available: Detailed experimental procedures and additional NMR, PL, EDX, DLS and TEM data. See DOI: 10.1039/C4NR05888G

  20. 18th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Workshop Proceedings, 3-6 August 2008, Vail, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B. L.

    2008-09-01

    The National Center for Photovoltaics sponsored the 18th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, held in Vail, CO, August 3-6, 2008. This meeting provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The theme of this year's meeting was 'New Directions for Rapidly Growing Silicon Technologies.'

  1. 13th Workshop on Crystalline Silicon Solar Cell Materials and Processes: Extended Abstracts and Papers

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B. L.; Rand, J.; Saitoh, T.; Sinton, R.; Stavola, M.; Swanson, D.; Tan, T.; Weber, E.; Werner, J.; Al-Jassim, M.

    2003-08-01

    The 13th Workshop will provide a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. It will offer an excellent opportunity for researchers in private industry and at universities to prioritize mutual needs for future collaborative research. The workshop is intended to address the fundamental aspects of impurities and defects in silicon: their properties, the dynamics during device processing, and their application for developing low-cost processes for manufacturing high-efficiency silicon solar cells. A combination of oral, poster, and discussion sessions will review recent advances in crystal growth, new cell structures, new processes and process characterization techniques, and cell fabrication approaches suitable for future manufacturing demands.

  2. Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

    International Nuclear Information System (INIS)

    Gunda, Naga Siva Kumar; Singh, Minashree; Norman, Lana; Kaur, Kamaljit; Mitra, Sushanta K.

    2014-01-01

    In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

  3. Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

    Energy Technology Data Exchange (ETDEWEB)

    Gunda, Naga Siva Kumar [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada); Singh, Minashree [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Norman, Lana [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada T6G 2V4 (Canada); Kaur, Kamaljit [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Mitra, Sushanta K., E-mail: sushanta.mitra@ualberta.ca [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada)

    2014-06-01

    In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

  4. Synthesis and properties of silane-fluoroacrylate grafted starch.

    Science.gov (United States)

    Qu, Jia; He, Ling

    2013-10-15

    The latex of silane-fluoroacrylate grafted starch for coating materials, VTMS-starch/P(MMA/BA/3FMA), is obtained by two step grafting reactions. Vinyltrimethoxysilane (VTMS) is primarily grafted onto starch by condensation between Si-OH and C-OH at 120 °C, and then the copolymer of methyl methacrylate (MMA), butyl acrylate (BA) and 2,2,2-trifluoroethyl methacrylate (3FMA) is grafted onto the VTMS-starch by emulsion polymerization. Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS) have been used to confirm the chemically grafting reactions in every step. The conversion percent, grafting percent and grafting efficiency for VTMS-starch/p(MMA/BA/3FMA) latex indicate that the optimum conditions should be controlled at 75 °C for 1h as VTMS-starch/P(MMA/BA/3FMA) in 1/3 weight ratio. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis have revealed that the latexes exhibit the uniform spherical particles of 40-60 nm in a narrow size distribution. The latex films perform the obvious hydrophobic (107°) property, lower surface free energy (25-35 mN/m) and the higher thermostability (330-440 °C) than starch (51°, 51.32 mN/m, 100-330 °C). Dynamic thermomechanical analysis (DMA) shows that the latex film could gain considerable toughness and strength with an elongation at break of 39.45% and a tensile strength of 11.97 MPa. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Low power high growth rate deposition of microcrystalline silicon

    OpenAIRE

    Feltrin, A; Bugnon, G; Meillaud, F; Bailat, J; Ballif, C

    2008-01-01

    Microcrystalline growth regimes and solar cells obtained in different pressure and silane depletion conditions are studied in a large area KAI-S plasma reactor. The microcrystalline material quality is systematically investigated by Fourier Transform Photocurrent Spectroscopy (FTPS) to evaluate the defect density. It is shown that higher pressure and silane depletion positively affect the material quality. A clear correlation between FTPS measurements and cell efficiency is established, showi...

  6. Process Research On Polycrystalline Silicon Material (PROPSM). [flat plate solar array project

    Science.gov (United States)

    Culik, J. S.

    1983-01-01

    The performance-limiting mechanisms in large-grain (greater than 1 to 2 mm in diameter) polycrystalline silicon solar cells were investigated by fabricating a matrix of 4 sq cm solar cells of various thickness from 10 cm x 10 cm polycrystalline silicon wafers of several bulk resistivities. Analysis of the illuminated I-V characteristics of these cells suggests that bulk recombination is the dominant factor limiting the short-circuit current. The average open-circuit voltage of the polycrystalline solar cells is 30 to 70 mV lower than that of co-processed single-crystal cells; the fill-factor is comparable. Both open-circuit voltage and fill-factor of the polycrystalline cells have substantial scatter that is not related to either thickness or resistivity. This implies that these characteristics are sensitive to an additional mechanism that is probably spatial in nature. A damage-gettering heat-treatment improved the minority-carrier diffusion length in low lifetime polycrystalline silicon, however, extended high temperature heat-treatment degraded the lifetime.

  7. Tin-free enantioselective radical reactions using silanes.

    Science.gov (United States)

    Sibi, Mukund P; Yang, Yong-Hua; Lee, Sunggi

    2008-12-04

    Readily available hexyl silane is an excellent choice as a H-atom donor and a chain carrier in Lewis acid mediated enantioselective radical reactions. Conjugate radical additions to alpha,beta-unsaturated imides at room temperature proceed in good yields and excellent enantioselectivities.

  8. Characterization of silane coated hollow sphere alumina-reinforced

    Indian Academy of Sciences (India)

    Silane coated hollow sphere alumina ceramic particles were moulded with ultra high molecular weight polyethylene (UHMWPE) to form a series of composites with alumina weight percent in the range from 15 to 50. The composites were prepared in a cylindrical mould using powder-processing technique. The composites ...

  9. 15th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Extended Abstracts and Papers

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B. L.

    2005-11-01

    The National Center for Photovoltaics sponsored the 15th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes, held in Vail, CO, August 7-10, 2005. This meeting provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The workshop addressed the fundamental properties of PV silicon, new solar cell designs, and advanced solar cell processing techniques. A combination of oral presentations by invited speakers, poster sessions, and discussion sessions reviewed recent advances in crystal growth, new cell designs, new processes and process characterization techniques, and cell fabrication approaches suitable for future manufacturing demands. The theme of this year's meeting was 'Providing the Scientific Basis for Industrial Success.' Specific sessions during the workshop included: Advances in crystal growth and material issues; Impurities and defects in Si; Advanced processing; High-efficiency Si solar cells; Thin Si solar cells; and Cell design for efficiency and reliability module operation. The topic for the Rump Session was ''Si Feedstock: The Show Stopper'' and featured a panel discussion by representatives from various PV companies.

  10. Micro-Raman spectroscopy as a tool for the characterization of silicon carbide in power semiconductor material processing

    Science.gov (United States)

    De Biasio, M.; Kraft, M.; Schultz, M.; Goller, B.; Sternig, D.; Esteve, R.; Roesner, M.

    2017-05-01

    Silicon carbide (SiC) is a wide band-gap semi-conductor material that is used increasingly for high voltage power devices, since it has a higher breakdown field strength and better thermal conductivity than silicon. However, in particular its hardness makes wafer processing difficult and many standard semi-conductor processes have to be specially adapted. We measure the effects of (i) mechanical processing (i.e. grinding of the backside) and (ii) chemical and thermal processing (i.e. doping and annealing), using confocal microscopy to measure the surface roughness of ground wafers and micro-Raman spectroscopy to measure the stresses induced in the wafers by grinding. 4H-SiC wafers with different dopings were studied before and after annealing, using depth-resolved micro-Raman spectroscopy to observe how doping and annealing affect: i.) the damage and stresses induced on the crystalline structure of the samples and ii.) the concentration of free electrical carriers. Our results show that mechanical, chemical and thermal processing techniques have effects on this semiconductor material that can be observed and characterized using confocal microscopy and high resolution micro Raman spectroscopy.

  11. Achievement report for fiscal 1997 on developing a silicon manufacturing process with reduced energy consumption. Investigation and research on analyzing practical application of a technology to manufacture solar cell silicon raw materials; 1997 nendo energy shiyo gorika silicon seizo process kaihatsu. Taiyo denchi silicon genryo seizo gijutsu no jitsuyoka kaiseki ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This paper describes the achievement in fiscal 1997 of analyzing practical application of a technology to manufacture solar cell silicon raw materials. Silicon consumption for solar cells in fiscal 1997 has increased to 2000-ton level, and the supply has been very tight. For drastic improvement in the demand and supply situation, development of SOG-Si manufacturing technology and its early practical application are desired. The development of the NEDO mass-production technology using melting and refining has completed constructing the process facilities in fiscal 1998, and will enter the stage of operational research. However, insufficiency in the basic data about behavior of impurities is inhibiting the development. In the substrate manufacturing technology, discussions have shown progress on use of diversifying silicons outside the standard by using the electromagnetic casting process. For slicing and processing the substrates, development of a high-performance slicing equipment and automatic rough rinsing machine is under way. Properties required on silicon raw materials vary considerably widely because of difference in cell making systems and conditions, which is attributable to unknown impurity behavior. When 1GW production is assumed, the cell module manufacturing cost is calculated as 137 yen/W, for which low-cost mass production for its realization, slicing productivity enhancement, and cost reduction are required. The paper also describes site surveys in overseas countries. (NEDO)

  12. Modeling the mechanical and aging properties of silicone rubber and foam - stockpile-historical & additively manufactured materials

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, A; Weisgraber, T H; Gee, R H

    2014-09-30

    M97* and M9763 belong to the M97xx series of cellular silicone materials that have been deployed as stress cushions in some of the LLNL systems. Their purpose of these support foams is to distribute the stress between adjacent components, maintain relative positioning of various components, and mitigate the effects of component size variation due to manufacturing and temperature changes. In service these materials are subjected to a continuous compressive strain over long periods of time. In order to ensure their effectiveness, it is important to understand how their mechanical properties change over time. The properties we are primarily concerned about are: compression set, load retention, and stress-strain response (modulus).

  13. Material parameters in a thick hydrogenated amorphous silicon detector and their effect on signal collection

    International Nuclear Information System (INIS)

    Qureshi, S.; Perez-Mendez, V.; Kaplan, S.N.; Fujieda, I.; Cho, G.; Street, R.A.

    1989-04-01

    Transient photoconductivity and ESR measurements were done to relate the ionized dangling bond density of thick hydrogenated amorphous silicon (a-Si:H) detectors. We found that only a fraction (/approximately/30--35%) of the total defect density as measured by ESR is ionized when the detector is biased into deep depletion. The measurements on annealed samples also show that this fraction is about 0.3. An explanation based on the shift of the Fermi energy is given. The measurements show that the time dependence of relaxation is a stretched exponential. 8 refs., 4 figs., 1 tab

  14. Advanced Silicon Carbide from Molecular Engineering and Actinide Fuels

    International Nuclear Information System (INIS)

    Meyer, D.J.M.; Garcia, J.; Guillaneux, D.; Wong-Chi-Man, M.; Moreau, J.J.E.

    2008-01-01

    In the frame of nuclear fuels studies for generation IV, carbides or oxycarbides assemblies are one of the engaged material for high temperature reactors. The design of the fuels is not yet defined but some structures are actually considered with SiC as matrix for the actinide fuel. In this work we have studied the synthesis of a multi-scale structure controlled SiC matrix using molecular silicon organometallic precursors. The aim of this work was to develop a way to obtain multi-scale SiC matrix material which could be engineered to fit in any fuel structure defined for generation IV fuels. The control of this multi-scale structure was done using several simulation methods specific of the low temperature solution synthesis of the precursor. In a first step, we have focused our effort on the synthesis of the SiC material. A first level of template was successfully done by the use of solid silica 500 nm balls. A second level of template was studied by the use of meso-porous silica, structured at a 50 nm level. At least, supra-molecular simulation in non aqueous media was considered with the difficulty to build a molecular assembly (inverse micelles). In a second step, we have functionalized the primary silane phase with actinide complexing agent in order to blend directly the actinide inside this primary phase in a controlled way. During these studies, a new one pot synthesis route to obtain the functionalized primary silane phase was developed. (authors)

  15. Preparation and characterization of flake graphite/silicon/carbon spherical composite as anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lai Jun [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Guo Huajun, E-mail: Lai_jun_@126.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Wang Zhixing; Li Xinhai; Zhang Xiaoping; Wu Feixiang; Yue Peng [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Flake graphite/silicon/carbon composite is synthesized via spray drying. Black-Right-Pointing-Pointer Flake graphite of {approx}0.5 {mu}m and glucose are used to prepare the composite. Black-Right-Pointing-Pointer The as-prepared composite shows spherical and porous appearance. Black-Right-Pointing-Pointer The composite shows nearly the same cycleability as commercial graphite in 20 cycles. Black-Right-Pointing-Pointer The composite shows a reversible capacity of 552 mAh/g at the 20th cycle. - Abstract: Using nano-Si, glucose and flake graphite of {approx}0.5 {mu}m as raw materials, flake graphite/silicon/carbon composite is successfully synthesized via spray drying and subsequent pyrolysis. The samples are characterized by XRD, SEM, TEM and electrochemical measurements. The composite is composed of flake graphite, nano-Si and amorphous glucose-pyrolyzed carbon and presents good spherical appearance. Some micron pores arising from the decomposition of glucose exist on the surface of the composite particles. The composite has a high reversible capacity of 602.7 mAh/g with an initial coulombic efficiency of 69.71%, and shows nearly the same cycleability as the commercial graphite in 20 cycles. Both the glucose-pyrolyzed carbon and the micron pores play important roles in improving the cycleability of the composite. The flake graphite/silicon/carbon composite electrode is a potential alternative to graphite for high energy-density lithium ion batteries.

  16. Apparatus for making molten silicon

    Science.gov (United States)

    Levin, Harry (Inventor)

    1988-01-01

    A reactor apparatus (10) adapted for continuously producing molten, solar grade purity elemental silicon by thermal reaction of a suitable precursor gas, such as silane (SiH.sub.4), is disclosed. The reactor apparatus (10) includes an elongated reactor body (32) having graphite or carbon walls which are heated to a temperature exceeding the melting temperature of silicon. The precursor gas enters the reactor body (32) through an efficiently cooled inlet tube assembly (22) and a relatively thin carbon or graphite septum (44). The septum (44), being in contact on one side with the cooled inlet (22) and the heated interior of the reactor (32) on the other side, provides a sharp temperature gradient for the precursor gas entering the reactor (32) and renders the operation of the inlet tube assembly (22) substantially free of clogging. The precursor gas flows in the reactor (32) in a substantially smooth, substantially axial manner. Liquid silicon formed in the initial stages of the thermal reaction reacts with the graphite or carbon walls to provide a silicon carbide coating on the walls. The silicon carbide coated reactor is highly adapted for prolonged use for production of highly pure solar grade silicon. Liquid silicon (20) produced in the reactor apparatus (10) may be used directly in a Czochralski or other crystal shaping equipment.

  17. Materials preparation and fabrication of pyroelectric polymer/silicon MOSFET detector arrays. Final report

    International Nuclear Information System (INIS)

    Bloomfield, P.

    1992-01-01

    The authors have delivered several 64-element linear arrays of pyroelectric elements fully integrated on silicon wafers with MOS readout devices. They have delivered detailed drawings of the linear arrays to LANL. They have processed a series of two inch wafers per submitted design. Each two inch wafer contains two 64 element arrays. After spin-coating copolymer onto the arrays, vacuum depositing the top electrodes, and polarizing the copolymer films so as to make them pyroelectrically active, each wafer was split in half. The authors developed a thicker oxide coating separating the extended gate electrode (beneath the polymer detector) from the silicon. This should reduce its parasitic capacitance and hence improve the S/N. They provided LANL three processed 64 element sensor arrays. Each array was affixed to a connector panel and selected solder pads of the common ground, the common source voltage supply connections, the 64 individual drain connections, and the 64 drain connections (for direct pyroelectric sensing response rather than the MOSFET action) were wire bonded to the connector panel solder pads. This entails (64 + 64 + 1 + 1) = 130 possible bond connections per 64 element array. This report now details the processing steps and the progress of the individual wafers as they were carried through from beginning to end

  18. Joining elements of silicon carbide

    International Nuclear Information System (INIS)

    Olson, B.A.

    1979-01-01

    A method of joining together at least two silicon carbide elements (e.g.in forming a heat exchanger) is described, comprising subjecting to sufficiently non-oxidizing atmosphere and sufficiently high temperature, material placed in space between the elements. The material consists of silicon carbide particles, carbon and/or a precursor of carbon, and silicon, such that it forms a joint joining together at least two silicon carbide elements. At least one of the elements may contain silicon. (author)

  19. Characterization of Amorphous Silicon Advanced Materials and PV Devices: Final Technical Report, 15 December 2001--31 January 2005

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P. C.

    2005-11-01

    The major objectives of this subcontract have been: (1) understand the microscopic properties of the defects that contribute to the Staebler-Wronski effect to eliminate this effect, (2) perform correlated studies on films and devices made by novel techniques, especially those with promise to improve stability or deposition rates, (3) understand the structural, electronic, and optical properties of films of hydrogenated amorphous silicon (a-Si:H) made on the boundary between the amorphous and microcrystalline phases, (4) search for more stable intrinsic layers of a-Si:H, (5) characterize the important defects, impurities, and metastabilities in the bulk and at surfaces and interfaces in a-Si:H films and devices and in important alloy systems, and (6) make state-of-the-art plasma-enhanced chemical vapor deposition (PECVD) devices out of new, advanced materials, when appropriate. All of these goals are highly relevant to improving photovoltaic devices based on a-Si:H and related alloys. With regard to the first objective, we have identified a paired hydrogen site that may be the defect that stabilizes the silicon dangling bonds formed in the Staebler-Wronski effect.

  20. Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

    KAUST Repository

    Ramadan, Khaled S.

    2013-02-08

    This work presents an SU-8 surface micromachining process using amorphous silicon as a sacrificial material, which also incorporates two metal layers for electrical excitation. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic applications due to its mechanical properties, biocompatibility and low cost. Amorphous silicon is used as a sacrificial layer in MEMS applications because it can be deposited in large thicknesses, and can be released in a dry method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using ;-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow out-of-plane electrostatic actuation for applications like MEMS switches and variable capacitors. In order to facilitate more flexibility for MEMS designers, the process can fabricate dimples that can be conductive or nonconductive. Additionally, this SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were optimized for two sets of thicknesses: thin (5-10 m) and thick (130 m). The process was tested fabricating MEMS switches, capacitors and thermal actuators. © 2013 IOP Publishing Ltd.

  1. Strengthening of oxidation resistant materials for gas turbine applications. [treatment of silicon ceramics for increased flexural strength and impact resistance

    Science.gov (United States)

    Kirchner, H. P.

    1974-01-01

    Silicon nitride and silicon carbide ceramics were treated to form compressive surface layers. On the silicon carbide, quenching and thermal exposure treatments were used, and on the silicon nitride, quenching, carburizing, and a combination of quenching and carburizing were used. In some cases substantial improvements in impact resistance and/or flexural strength were observed. The presence of compressive surface stresses was demonstrated by slotted rod tests.

  2. Disilane as a growth rate catalyst of plasma deposited microcrystalline silicon thin films

    Science.gov (United States)

    Dimitrakellis, P.; Kalampounias, A. G.; Spiliopoulos, N.; Amanatides, E.; Mataras, D.; Lahootun, V.; Coeuret, F.; Madec, A.

    2016-07-01

    The effect of small disilane addition on the gas phase properties of silane-hydrogen plasmas and the microcrystalline silicon thin films growth is presented. The investigation was conducted in the high pressure regime and for constant power dissipation in the discharge with the support of plasma diagnostics, thin film studies and calculations of discharge microscopic parameters and gas dissociation rates. The experimental data and the calculations show a strong effect of disilane on the electrical properties of the discharge in the pressure window from 2 to 3 Torr that is followed by significant raise of the electron number density and the drop of the sheaths electric field intensity. Deposition rate measurements show an important four to six times increase even for disilane mole fractions as low as 0.3 %. The deposition rate enhancement was followed by a drop of the material crystalline volume fraction but films with crystallinity above 40 % were deposited with different combinations of total gas pressure, disilane and silane molar ratios. The enhancement was partly explained by the increase of the electron impact dissociation rate of silane which rises by 40% even for 0.1% disilane mole fraction. The calculations of the gas usage, the dissociation and the deposition efficiencies show that the beneficial effect on the growth rate is not just the result of the increase of Si-containing molecules density but significant changes on the species participating to the deposition and the mechanism of the film growth are caused by the disilane addition. The enhanced participation of the highly sticking to the surface radical such as disilylene, which is the main product of disilane dissociation, was considered as the most probable reason for the significant raise of the deposition efficiency. The catalytic effect of such type of radical on the surface reactivity of species with lower sticking probability is further discussed, while it is also used to explain the restricted

  3. Disilane as a growth rate catalyst of plasma deposited microcrystalline silicon thin films

    International Nuclear Information System (INIS)

    Dimitrakellis, P.; Amanatides, E.; Mataras, D.; Kalampounias, A. G.; Spiliopoulos, N.; Lahootun, V.; Coeuret, F.; Madec, A.

    2016-01-01

    The effect of small disilane addition on the gas phase properties of silane-hydrogen plasmas and the microcrystalline silicon thin films growth is presented. The investigation was conducted in the high pressure regime and for constant power dissipation in the discharge with the support of plasma diagnostics, thin film studies and calculations of discharge microscopic parameters and gas dissociation rates. The experimental data and the calculations show a strong effect of disilane on the electrical properties of the discharge in the pressure window from 2 to 3 Torr that is followed by significant raise of the electron number density and the drop of the sheaths electric field intensity. Deposition rate measurements show an important four to six times increase even for disilane mole fractions as low as 0.3 %. The deposition rate enhancement was followed by a drop of the material crystalline volume fraction but films with crystallinity above 40 % were deposited with different combinations of total gas pressure, disilane and silane molar ratios. The enhancement was partly explained by the increase of the electron impact dissociation rate of silane which rises by 40% even for 0.1% disilane mole fraction. The calculations of the gas usage, the dissociation and the deposition efficiencies show that the beneficial effect on the growth rate is not just the result of the increase of Si-containing molecules density but significant changes on the species participating to the deposition and the mechanism of the film growth are caused by the disilane addition. The enhanced participation of the highly sticking to the surface radical such as disilylene, which is the main product of disilane dissociation, was considered as the most probable reason for the significant raise of the deposition efficiency. The catalytic effect of such type of radical on the surface reactivity of species with lower sticking probability is further discussed, while it is also used to explain the restricted

  4. Development in fiscal 1998 of silicon manufacturing process to rationalize energy usage. Surveys and researches on analysis of practical application of technology to manufacture silicon raw materials for solar cells; 1998 nendo energy shiyo gorika silicon seizo process kaihatsu seika hokokusho. Taiyo denchi silicon genryo seizo gijutsu no jitsuyoka kaiseki ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    With an objective to develop a mass production technology to manufacture silicon raw materials for solar cells, and assist its practical application, surveys and analyses were performed on trends in development of the related technologies, the problems therein , market trends and industrial trends thereof. This paper summarizes the achievements in fiscal 1998. The worldwide production amount of solar cells in 1998 is estimated to have achieved 150 MW, and the silicon consumption reached the level of 2,300 tons. In spite of the economic recession environment, there was no change in the expansion trend. In developing an SOG-Si mass production and manufacturing technology, construction of pilot plants for each process has been completed, and entered into the operation research phase. In developing a technology to manufacture high quality poly-crystalline silicon substrates, fabrication has been completed on the on-line ingot cutting equipment and the plasma heating equipment, and the stage is now in operation research of continuous electromagnetic casting process. The conversion efficiency of the poly-crystalline silicon solar cells is 14 to 16% at the mass production level, whose enhancement requires indispensably the improvement in quality of the substrate. Discussions are required on the ingot manufacturing conditions in coordination with improvement in the cell manufacturing technology. (NEDO)

  5. Fast Formation of Conductive Material by Simultaneous Chemical Process for Infilling Through-Silicon Via

    Science.gov (United States)

    Kawakita, Jin; Chikyow, Toyohiro

    2012-06-01

    It is necessary to develop a fast and inexpensive fabrication process of vertical electric wiring by through-silicon via (TSV) technology for advanced three-dimensional semiconductor devices. In this research, a fast-forming conductive composite was successfully developed by simultaneous deposition of conductive organic polymer (polypyrrole) and metal (silver) from the liquid phase, accelerated by photoirradiation. The growth rate of the composite was 38 nm·s-1, which is more than 10 times higher than that of copper by conventional plating. The electric conductivity of the composite was 2.1×104 Ω-1·cm-1, which is on the same level as general metal conductors. In addition, the effects of reaction conditions on the growth rate and the conductivity of the composites were revealed. From these results, the infilling time of the TSV was expected to shorten from the present 2-10 h to 5-10 m.

  6. Structure and properties of nanocrystalline soft magnetic composite materials with silicon polymer matrix

    International Nuclear Information System (INIS)

    Dobrzanski, L.A.; Nowosielski, R.; Konieczny, J.; PrzybyI, A.; WysIocki, J.

    2005-01-01

    The paper concerns investigation of nanocrystalline composites technology preparation. The composites in the form of rings with rectangular transverse section, and with polymer matrix and nanocrystalline metallic powders fulfillment were made, for obtaining good ferromagnetic properties. The nanocrystalline ferromagnetic powders were manufactured by high-energy ball milling of metallic glasses strips in an as-quenched state. Generally for investigation, Co matrix alloys with the silicon polymer were used. Magnetic properties in the form of hysteresis loop by rings method were measured. Generally composite cores showed lower soft ferromagnetic properties than winded cores of nanocrystalline strips, but composite cores showed interesting mechanical properties. Furthermore, the structure of strips and powders on properties of composites were investigated

  7. Comparative study on electrical properties of atomic layer deposited high-permittivity materials on silicon substrates

    International Nuclear Information System (INIS)

    Duenas, S.; Castan, H.; Garcia, H.; Barbolla, J.; Kukli, K.; Ritala, M.; Leskelae, M.

    2005-01-01

    Deep level transient spectroscopy, capacitance-voltage and conductance transient measurement techniques have been applied in order to evaluate the electrical quality of thin high-permittivity oxide layers on silicon. The oxides studied included HfO 2 film grown from two different oxygen-free metal precursors and Ta 2 O 5 and Nb 2 O 5 nanolaminates. The interface trap densities correlated to the oxide growth chemistry and semiconductor substrate treatment. No gap state densities induced by structural disorder were measured in the films grown on chemical SiO 2 . Trap densities were also clearly lower in HfO 2 films compared to Ta 2 O 5 -Nb 2 O 5

  8. Eighth workshop on crystalline silicon solar cell materials and processes: Extended abstracts and papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    The theme of this workshop is Supporting the Transition to World Class Manufacturing. This workshop provides a forum for an informal exchange of information between researchers in the photovoltaic and non-photovoltaic fields on various aspects of impurities and defects in silicon, their dynamics during device processing, and their application in defect engineering. This interaction helps establish a knowledge base that can be used for improving device fabrication processes to enhance solar-cell performance and reduce cell costs. It also provides an excellent opportunity for researchers from industry and universities to recognize mutual needs for future joint research. The workshop format features invited review presentations, panel discussions, and two poster sessions. The poster sessions create an opportunity for both university and industrial researchers to present their latest results and provide a natural forum for extended discussions and technical exchanges.

  9. Relationship of microstructure properties to oxygen impurities in nanocrystalline silicon photovoltaic materials

    Science.gov (United States)

    Xu, H.; Wen, C.; Liu, H.; Li, Z. P.; Shen, W. Z.

    2013-03-01

    We have fully investigated the correlation of microstructure properties and oxygen impurities in hydrogenated nanocrystalline silicon photovoltaic films. The achievement has been realized through a series of different hydrogen dilution ratio treatment by plasma enhanced chemical vapor deposition system. Raman scattering, x-ray diffraction, and ultraviolet-visible transmission techniques have been employed to characterize the physical structural characterization and to elucidate the structure evolution. The bonding configuration of the oxygen impurities was investigated by x-ray photoelectron spectroscopy and the Si-O stretching mode of infrared-transmission, indicating that the films were well oxidized in SiO2 form. Based on the consistence between the proposed structure factor and the oxygen content, we have demonstrated that there are two dominant disordered structure regions closely related to the post-oxidation contamination: plate-like configuration and clustered microvoids.

  10. Surface and interfacial chemistry of high-k dielectric and interconnect materials on silicon

    Science.gov (United States)

    Kirsch, Paul Daniel

    Surfaces and interfaces play a critical role in the manufacture and function of silicon based integrated circuits. It is therefore reasonable to study the chemistries at these surfaces and interfaces to improve existing processes and to develop new ones. Model barium strontium titanate high-k dielectric systems have been deposited on ultrathin silicon oxynitride in ultrahigh vacuum. The resulting nanostructures are characterized with secondary ion mass spectroscopy (SIMS) and X-ray photoelectron spectroscopy (XPS). An interfacial reaction between Ba and Sr atoms and SiOxNy was found to create silicates, BaSixOy or SrSi xOy. Inclusion of N in the interfacial oxide decreased silicate formation in both Ba and Sr systems. Furthermore, inclusion of N in the interfacial oxide decreased the penetration of Ba and Sr containing species, such as silicides and silicates. Sputter deposited HfO2 was studied on nitrided and unnitrided Si(100) surfaces. XPS and SIMS were used to verify the presence of interfacial HfSixOy and estimate its relative amount on both nitrided and unnitrided samples. More HfSixOy formed without the SiNx interfacial layer. These interfacial chemistry results are then used to explain the electrical measurements obtained from metal oxide semiconductor (MOS) capacitors. MOS capacitors with interfacial SiNx exhibit reduced leakage current and increased capacitance. Lastly, surface science techniques were used to develop a processing technique for reducing thin films of copper (II) and copper (I) oxide to copper. Deuterium atoms (D*) and methyl radicals (CH3*) were shown to reduce Cu 2+ and/or Cu1+ to Cu0 within 30 min at a surface temperature of 400 K under a flux of 1 x 1015 atoms/cm2s. Temperature programmed desorption experiments suggest that oxygen leaves the surface as D2O and CO2 for the D* and CH3* treated surfaces, respectively.

  11. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

    2014-11-14

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD.

  12. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    International Nuclear Information System (INIS)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam

    2014-01-01

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD

  13. Silicon as a virtual plasmonic material: Acquisition of its transient optical constants and the ultrafast surface plasmon-polariton excitation

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, P. A.; Ionin, A. A.; Kudryashov, S. I., E-mail: sikudr@sci.lebedev.ru; Makarov, S. V.; Rudenko, A. A. [Lebedev Physical Institute (Russian Federation); Saltuganov, P. N. [Moscow Institute of Physics and Technology (State University) (Russian Federation); Seleznev, L. V.; Yurovskikh, V. I.; Zayarny, D. A. [Lebedev Physical Institute (Russian Federation); Apostolova, T. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energetics (Bulgaria)

    2015-06-15

    Ultrafast intense photoexcitation of a silicon surface is complementarily studied experimentally and theoretically, with its prompt optical dielectric function obtained by means of time-resolved optical reflection microscopy and the underlying electron-hole plasma dynamics modeled numerically, using a quantum kinetic approach. The corresponding transient surface plasmon-polariton (SPP) dispersion curves of the photo-excited material were simulated as a function of the electron-hole plasma density, using the derived optical dielectric function model, and directly mapped at several laser photon energies, measuring spatial periods of the corresponding SPP-mediated surface relief nanogratings. The unusual spectral dynamics of the surface plasmon resonance, initially increasing with the increase in the electron-hole plasma density but damped at high interband absorption losses induced by the high-density electron-hole plasma through instantaneous bandgap renormalization, was envisioned through the multi-color mapping.

  14. 16th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes; Program, Extended Abstracts, and Papers

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B. L.

    2006-08-01

    The National Center for Photovoltaics sponsored the 16th Workshop on Crystalline Silicon Solar Cells and Modules: Materials and Processes held August 6-9, 2006 in Denver, Colorado. The workshop addressed the fundamental properties of PV-Si, new solar cell designs, and advanced solar cell processing techniques. It provided a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. The Workshop Theme was: "Getting more (Watts) for Less ($i)". A combination of oral presentations by invited speakers, poster sessions, and discussion sessions reviewed recent advances in crystal growth, new cell structures, new processes and process characterization techniques, and cell fabrication approaches suitable for future manufacturing demands. The special sessions included: Feedstock Issues: Si Refining and Purification; Metal-impurity Engineering; Thin Film Si; and Diagnostic Techniques.

  15. Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process, task 2. LSSA project

    Science.gov (United States)

    Duffy, M. T.; Berkman, S.; Moss, H. S.; Cullen, G. W.

    1978-01-01

    The results of emission spectroscopic analysis indicate that molten silicon can remain in contact with hot-pressed Si3N4 (99.2 percent theoretical density) for prolonged periods without attaining the impurity content level of the nitride. Although MgO was used as binder, Mg was not found present in the silicon sessile drop in quantities much above the level initially present in the silicon source material. Preliminary experiments with EFG-type dies coated with CVD Si3N4 or CVD SiOxNy indicate that capillary rise does not occur readily in these dies. The same was found to be true of hot-pressed and reaction-sintered Si3N4 obtained commercially. However, when dies were formed by depositing CVD layers on shaped silicon slabs, a column of molten silicon was maintained in each CVD die while being heated in contact with a crucible of molten silicon. Preliminary wetting of dies appears necessary for EFG growth. Several ribbon growth experiments were performed from V-shaped dies.

  16. FY 1991 Report on the results of the research and development of silicon-based high-molecular-weight materials; 1991 nendo keisokei kobunshi zairyo no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-03-01

    The research and development project has been started to establish the basic technologies for molecular designs, synthesis, material production and evaluation of silicon-based high-molecular-weight materials expected to exhibit excellent characteristics, e.g., electro-optical functions, resistance to heat, flame retardance and mechanical properties. The efforts in FY 1991, the first year for the 10-year project, are mainly directed to the surveys on the R and D trends, both domestic and foreign, to clarify the relationship between the structures and functions/properties. The R and D projects followed include the technologies for synthesizing (1) electroconductive silicon-based high-molecular-weight materials, (2) novel silicon-based high-molecular-weight materials capable of drawing circuits, (3) novel, light-emitting silicon-based high-molecular-weight materials and (4) silicon-based opto-electric conversion materials for the electro-optical functional high-molecular-weight materials; and (1) synthesis of high-molecular-weight structural materials of sea island structure, (2) technologies for forming inter-penetrating type structures (IPN), (3) development of composite structural materials of organometallic complex and silicon-based high-molecular-weight material, and (4) development of silicon-based high-molecular-weight materials of ring structure for the high-molecular-weight structural materials. (NEDO)

  17. Protein patterning on polycrystalline silicon-germanium via standard UV lithography for bioMEMS applications

    Energy Technology Data Exchange (ETDEWEB)

    Lenci, S., E-mail: silvia.lenci@gmail.com [Dipartimento di Ingegneria dell' Informazione, University of Pisa, Via G. Caruso 16, I-56122 Pisa (Italy); imec, Kapeldreef 75, Leuven B-3001 (Belgium); Tedeschi, L.; Domenici, C.; Lande, C. [Istituto di Fisiologia Clinica, CNR, via G. Moruzzi 1, Pisa I-56124 (Italy); Nannini, A.; Pennelli, G.; Pieri, F. [Dipartimento di Ingegneria dell' Informazione, University of Pisa, Via G. Caruso 16, I-56122 Pisa (Italy); Severi, S. [imec, Kapeldreef 75, Leuven B-3001 (Belgium)

    2010-10-12

    Polycrystalline silicon-germanium (poly-SiGe) is a promising structural material for the post-processing of micro electro-mechanical systems (MEMS) on top of complementary metal-oxide-semiconductor (CMOS) substrates. Combining MEMS and CMOS allows for the development of high-performance devices. We present for the first time selective protein immobilization on top of poly-SiGe surfaces, an enabling technique for the development of novel poly-SiGe based MEMS biosensors. Active regions made of 3-aminopropyl-triethoxysilane (APTES) were defined using silane deposition onto photoresist patterns followed by lift-off in organic solvents. Subsequently, proteins were covalently bound on the created APTES patterns. Fluorescein-labeled human serum albumin (HSA) was used to verify the immobilization procedure while the binding capability of the protein layer was tested by an antigen-labeled antibody pair. Inspection by fluorescence microscopy showed protein immobilization inside the desired bioactive areas and low non-specific adsorption outside the APTES pattern. Furthermore, the quality of the silane patches was investigated by treatment with 30 nm-diameter gold nanoparticles and scanning electron microscope observation. The developed technique is therefore a promising first step towards the realization of poly-SiGe based biosensors.

  18. Modification of silicon nitride surfaces with GOPES and APTES for antibody immobilization: computational and experimental studies

    International Nuclear Information System (INIS)

    To, Thien Dien; Nguyen, Anh Tuan; Phan, Khoa Nhat Thanh; Truong, An Thu Thi; Doan, Tin Chanh Duc; Dang, Chien Mau

    2015-01-01

    Chemical modification of silicon nitride (SiN) surfaces by silanization has been widely studied especially with 3-(aminopropyl)triethoxysilane (APTES) and 3-(glycidyloxypropyl) dimethylethoxysilane (GOPES). However few reports performed the experimental and computational studies together. In this study, surface modification of SiN surfaces with GOPES and APTES covalently bound with glutaraldehyde (GTA) was investigated for antibody immobilization. The monoclonal anti-cytokeratin-FITC (MACF) antibody was immobilized on the modified SiN surfaces. The modified surfaces were characterized by water contact angle measurements, atomic force microscopy and fluorescence microscopy. The FITC-fluorescent label indicated the existence of MACF antibody on the SiN surfaces and the efficiency of the silanization reaction. Absorption of APTES and GOPES on the oxidized SiN surfaces was computationally modeled and calculated by Materials Studio software. The computational and experimental results showed that modification of the SiN surfaces with APTES and GTA was more effective than the modification with GOPES. (paper)

  19. Impacts of Different Functional Groups on the Kinetic Rates of α-Amine Ketoximesilanes Hydrolysis in the Preparation of Room Temperature Vulcanized Silicone Rubber.

    Science.gov (United States)

    Xu, Huihui; Liu, Zihou; Liu, Qingyang; Bei, Yiling; Zhu, Qingzeng

    2018-05-13

    α-Amine ketoximesilanes are proven to be effective crosslinkers in the preparation of ketone-oxime one-component room temperature vulcanized (RTV) silicone rubber without the use of toxic metal catalyst. This work aimed to investigate the hydrolysis kinetic of α-amine ketoximesilanes, which is vitally important for the preparation of RTV silicone rubber. Five kinds of α-amine ketoximesilanes, namely α-(N,N-diethyl)aminomethyltri(methylethylketoxime)silane (DEMOS), α-(N,N-di-n-butyl)aminomethyltri(methylethylketoxime)silane (DBMOS), α-(N-n-butyl)aminomethyltri(methylethylketoxime)silane (n-BMOS), α-(N-cyclohexyl)aminomethyltri(methylethylketoxime)silane (CMOS) and α-(β-aminomethyl)aminomethyltri(methylethylketoxime)silane (AEMOS), were successfully obtained and confirmed using Fourier transform infrared spectrometer (FT-IR) and hydrogen-1 nuclear magnetic resonance ( ¹H NMR). Kinetics of hydrolysis reactions were measured by FT-IR and conductivity. Our results illustrated that the kinetic constant rates ranged from 12.2 × 10 −4 s −1 to 7.6 × 10 −4 s −1 , with the decreasing order of DEMOS > n-BMOS > DBMOS > CMOS > AEMOS at the given temperature and humidity. Better performances of thermal stability could be achieved when using the α-amine ketoximesilanes as crosslinkers in the preparation of RTV silicon rubber than that of RTV silicone rubber with the use of methyltri(methylethylketoxime)silane (MOS) as a crosslinker and organic tin as a catalyst.

  20. Development of antibacterial quaternary ammonium silane coatings on polyurethane catheters

    Czech Academy of Sciences Publication Activity Database

    Zanini, S.; Polissi, A.; Maccagni, E.A.; Dell'Orto, E.C.; Liberatore, Chiara; Riccardi, C.

    2015-01-01

    Roč. 451, Aug (2015), 78-84 ISSN 0021-9797 R&D Projects: GA MŠk EE2.3.20.0143 Grant - others:OP VK 6(XE) CZ.1.07/2.3.00/20.0143 Institutional support: RVO:68378271 Keywords : plasma-induced graft-polymerization * acrylic acid * ATR/FTIR * AFM * quaternary ammonium silane * Escherichia coli Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.782, year: 2015

  1. Fiscal 1992 R and D project for next generation infrastructure technology. Report on results of R and D on silicon-based polymeric material; 1992 nendo keisokei kobunshi zairyo no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-03-01

    R and D was conducted with the purpose of establishing fundamental technologies for molecular design, synthesis, material formation and evaluation method concerning silicon-based polymer. with the fiscal 1992 results summarized. In the studies on synthesis technology of electrically conductive silicon-based polymeric materials, silicon-based compounds were synthesized including in particular -Si-Si- bond and carbon multiple bond like -C-C-, with acquisition/analysis of material data started. In the studies on new silicon-based polymeric materials capable of circuit plotting, syntheses were performed for network polysilanes through the disproportionation reaction of alkoxydisilanes. In the studies on new silicon-based polymeric materials having a light emitting function, evaluation of oxidation-reduction potential and search for synthesizing conditions were performed for halosilanes and hydrosilanes. In the studies on silicon-based photoelectric conversion materials, molecular design progressed using a crystal orbital method. Furthermore, researches were implemented on such subjects as silicon-based polymeric materials having a sea-island structure, interpenetrating polymer network forming technologies, and composite structural materials composed of organic metallic complex and silicon-based polymers. (NEDO)

  2. Spectroscopy of nanosized composites silicon-organic polymer/nanoporous silicas

    International Nuclear Information System (INIS)

    Ostapenko, N.; Kozlova, N.; Suto, S.; Watanabe, A.

    2006-01-01

    Fluorescence and excitation spectra (T=5-290 K) of nanosized silicon-organic polymers poly(di-n-hexylsilane) and poly(methyl(phenyl)silane) incorporated into porous silica materials MCM-41 and SBA-15 have been studied with varying pore diameter from 2.8 to 10 nm. The controlled variation of the pore diameter in a wide range (2.8-10 nm) permitted us, for the first time, to investigate the optical properties of the polymers on their transition from isolated macromolecules to a film. It is found that this transition depends on polymer type and occurs via the formation of new spatially independent structures of the polymers not observed in the spectra of the film, namely, via the formation of disordered and (or) ordered conformations of polymer chains and clusters

  3. A molecular method to assess bioburden embedded within silicon-based resins used on modern spacecraft materials

    Science.gov (United States)

    Stam, Christina N.; Bruckner, James; Spry, J. Andy; Venkateswaran, Kasthuri; La Duc, Myron T.

    2012-07-01

    Current assessments of bioburden embedded in spacecraft materials are based on work performed in the Viking era (1970s), and the ability to culture organisms extracted from such materials. To circumvent the limitations of such approaches, DNA-based techniques were evaluated alongside established culturing techniques to determine the recovery and survival of bacterial spores encapsulated in spacecraft-qualified polymer materials. Varying concentrations of Bacillus pumilus SAFR-032 spores were completely embedded in silicone epoxy. An organic dimethylacetamide-based solvent was used to digest the epoxy and spore recovery was evaluated via gyrB-targeted qPCR, direct agar plating, most probably number analysis, and microscopy. Although full-strength solvent was shown to inhibit the germination and/or outgrowth of spores, dilution in excess of 100-fold allowed recovery with no significant decrease in cultivability. Similarly, qPCR (quantitative PCR) detection sensitivities as low as ~103 CFU ml-1 were achieved upon removal of inhibitory substances associated with the epoxy and/or solvent. These detection and enumeration methods show promise for use in assessing the embedded bioburden of spacecraft hardware.

  4. Silicon Qubits

    Energy Technology Data Exchange (ETDEWEB)

    Ladd, Thaddeus D. [HRL Laboratories, LLC, Malibu, CA (United States); Carroll, Malcolm S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-28

    Silicon is a promising material candidate for qubits due to the combination of worldwide infrastructure in silicon microelectronics fabrication and the capability to drastically reduce decohering noise channels via chemical purification and isotopic enhancement. However, a variety of challenges in fabrication, control, and measurement leaves unclear the best strategy for fully realizing this material’s future potential. In this article, we survey three basic qubit types: those based on substitutional donors, on metal-oxide-semiconductor (MOS) structures, and on Si/SiGe heterostructures. We also discuss the multiple schema used to define and control Si qubits, which may exploit the manipulation and detection of a single electron charge, the state of a single electron spin, or the collective states of multiple spins. Far from being comprehensive, this article provides a brief orientation to the rapidly evolving field of silicon qubit technology and is intended as an approachable entry point for a researcher new to this field.

  5. 太阳能硅料化学清洗研究进展%Development of chemical cleaning for solar energy silicon material

    Institute of Scientific and Technical Information of China (English)

    申燕; 贾艳飞; 姚旭; 张健; 廉佳林

    2016-01-01

    Silicon as the main material of solar photovoltaic power generation in the solar photovoltaic industry, the demand for silicon material cleanliness also gradualy increases under the background of the rapid development of the market. Chemical cleaning is the main method of silicon material cleaning. In this paper, the research progress of the standard cleaning method ( RCA ) and depending on the silicon material by RCA method to develop other chemical cleaning method was reviewed.%多晶硅作为太阳能光伏发电的主要材料,在太阳能光伏产业市场迅速发展的大背景下,对硅料清洁度的需求也逐步增加。化学清洗是目前硅料清洗的主要方法。本文综述了近年来硅料化学清洗的基本方法(RCA)及根据硅料的不同由RCA法发展出的其他化学清洗方法。

  6. A Difference in Using Atomic Layer Deposition or Physical Vapour Deposition TiN as Electrode Material in Metal-Insulator-Metal and Metal-Insulator-Silicon Capacitors

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, Robertus A.M.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2011-01-01

    In this work, metal-insulator-metal (MIM) and metal-insulator-silicon (MIS) capacitors are studied using titanium nitride (TiN) as the electrode material. The effect of structural defects on the electrical properties on MIS and MIM capacitors is studied for various electrode configurations. In the

  7. Influence of surface conditions and silane agent on the bond of resin to IPS Empress 2 ceramic.

    Science.gov (United States)

    Spohr, Ana Maria; Sobrinho, Lourenço Correr; Consani, Simonides; Sinhoreti, Mario Alexandre Coelho; Knowles, Jonathan C

    2003-01-01

    The aim of this study was to evaluate the effect of different ceramic surface treatments on the tensile bond strength between IPS Empress 2 ceramic framework and Rely X adhesive resin cement, with or without the application of a silane coupling agent. One hundred twenty disks were made, embedded in resin, and randomly divided into six groups: group 1 = sandblasting (100 microm), no silanation; group 2 = sandblasting (100 microm), silane treatment; group 3 = sandblasting (50 microm), no silanation; group 4 = sandblasting (50 microm), silane treatment; group 5 = hydrofluoric acid etching, no silanation; and group 6 = hydrofluoric acid etching, silane treatment. The disks were bonded into pairs with adhesive resin cement. All samples were stored in distilled water at 37 degrees C for 24 hours and then thermocycled. The samples were submitted to tensile testing. The use of silane improved the bond strength in relation to the groups in which silane was not applied (P Empress 2 ceramic framework and resin agent.

  8. Biosurfactants prevent in vitro Candida albicans biofilm formation on resins and silicon materials for prosthetic devices.

    Science.gov (United States)

    Cochis, Andrea; Fracchia, Letizia; Martinotti, Maria Giovanna; Rimondini, Lia

    2012-06-01

    The aim of this study was to evaluate in vitro the preventive antiadhesion activity of biosurfactants against Candida albicans biofilm. Disks of silicon and acrylic resin for denture prostheses were precoated with increasing concentrations of biosurfactants obtained from endophyte biofilms selected from Robinia pseudoacacia and from Nerium oleander, and afterward infected with C. albicans cells. The number of biofilm cells were detected by colony-forming unit (CFU) counting, cell viability was established by the 2,3-bis(2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenyl amino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay, and biosurfactant cytotoxicity was evaluated by the [3-(4,5-dimethyliazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium] (MTT) assay. Chlorhexidine was used as control. Precoating with biosurfactants caused a greater reduction (P biosurfactants was observed at low concentrations (78.12 μg/mL and 156.12 μg/mL) which were noncytotoxic. This study demonstrated the preventive antiadhesion activity of biosurfactants against C. albicans biofilm. These agents are amphiphilic, interfere with microbial adhesion, and demonstrate cycompatibility with epithelial cells and fibroblasts. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials

    Energy Technology Data Exchange (ETDEWEB)

    Fiorentino, Giuseppe, E-mail: g.fiorentino@tudelft.nl; Morana, Bruno [Department of Microelectronic, Delft University of Technology, Feldmannweg 17, 2628 CT Delft (Netherlands); Forte, Salvatore [Department of Electronic, University of Naples Federico II, Piazzale Tecchio, 80125 Napoli (Italy); Sarro, Pasqualina Maria [Department of Microelectronic, Delft University of Technology, Feldmannweg 17, 2628 CT, Delft (Netherlands)

    2015-01-15

    In this paper, the authors study the protective effect against oxidation of a thin layer of atomic layer deposited (ALD) aluminum oxide (Al{sub 2}O{sub 3}). Nitrogen doped silicon carbide (poly-SiC:N) based microheaters coated with ALD Al{sub 2}O{sub 3} are used as test structure to investigate the barrier effect of the alumina layers to oxygen and water vapor at very high temperature (up to 1000 °C). Different device sets have been fabricated changing the doping levels, to evaluate possible interaction between the dopants and the alumina layer. The as-deposited alumina layer morphology has been evaluated by means of AFM analysis and compared to an annealed sample (8 h at 1000 °C) to estimate the change in the grain structure and the film density. The coated microheaters are subjected to very long oxidation time in dry and wet environment (up to 8 h at 900 and 1000 °C). By evaluating the electrical resistance variation between uncoated reference devices and the ALD coated devices, the oxide growth on the SiC is estimated. The results show that the ALD alumina coating completely prevents the oxidation of the SiC up to 900 °C in wet environment, while an oxide thickness reduction of 50% is observed at 1000 °C compared to uncoated devices.

  10. Influence of Containment on the Growth of Silicon-Germanium (ICESAGE): A Materials Science Investigation

    Science.gov (United States)

    Volz, M. P.; Mazuruk, K.; Croll, A.

    2014-01-01

    A series of Ge Si crystal growth experiments are planned to be conducted in the Low 1-x x Gradient Furnace (LGF) onboard the International Space Station. The primary objective of the research is to determine the influence of containment on the processing-induced defects and impurity incorporation in germanium-silicon alloy crystals. A comparison will be made between crystals grown by the normal and "detached" Bridgman methods and the ground-based float zone technique. Crystals grown without being in contact with a container have superior quality to otherwise similar crystals grown in direct contact with a container, especially with respect to impurity incorporation, formation of dislocations, and residual stress in crystals. "Detached" or "dewetted" Bridgman growth is similar to regular Bridgman growth in that most of the melt is in contact with the crucible wall, but the crystal is separated from the wall by a small gap, typically of the order of 10-100 microns. Long duration reduced gravity is essential to test the proposed theory of detached growth. Detached growth requires the establishment of a meniscus between the crystal and the ampoule wall. The existence of this meniscus depends on the ratio of the strength of gravity to capillary forces. On Earth, this ratio is large and stable detached growth can only be obtained over limited conditions. Crystals grown detached on the ground exhibited superior structural quality as evidenced by measurements of etch pit density, synchrotron white beam X-ray topography and double axis X-ray diffraction.

  11. Structural and magnetic properties of the nanocomposite materials based on a mesoporous silicon dioxide matrix

    Energy Technology Data Exchange (ETDEWEB)

    Grigor’eva, N. A., E-mail: natali@lns.pnpi.spb.ru [St. Petersburg State University (Russian Federation); Eckerlebe, H. [Helmholtz-Zentrum Geesthacht (Germany); Eliseev, A. A.; Lukashin, A. V.; Napol’skii, K. S. [Moscow State University (Russian Federation); Kraje, M. [Reactor Institute Delft (Netherlands); Grigor’ev, S. V. [St. Petersburg State University (Russian Federation)

    2017-03-15

    The structural and magnetic properties of the mesoporous systems based on silicon dioxide with a regular hexagonal arrangement of pores several microns in length and several nanometers in diameter, which are filled with iron compound nanofilaments in various chemical states, are studied in detail. The studies are performed using the following mutually complementary methods: transmission electron microscopy, SQUID magnetometry, electron spin resonance, Mössbauer spectroscopy, polarized neutron small-angle diffraction, and synchrotron radiation diffraction. It is shown that the iron nanoparticles in pores are mainly in the γ phase of Fe{sub 2}O{sub 3} with a small addition of the α phase and atomic iron clusters. The effective magnetic field acting on a nanofilament from other nanofilaments is 11 mT and has a dipole nature, the ferromagnetic–paramagnetic transition temperature is in the range 76–94 K depending on the annealing temperature of the samples, and the temperature that corresponds to the change in the magnetic state of the iron oxide nanofilaments is T ≈ 50–60 K at H = 0 and T ≈ 80 K at H = 300 mT. It is also shown that the magnetization reversal of an array of nanofilaments is caused by the magnetostatic interaction between nanofilaments at the fields that are lower than the saturation field.

  12. Surface characterization and cytocompatibility evaluation of silanized magnesium alloy AZ91 for biomedical applications

    Directory of Open Access Journals (Sweden)

    Agnieszka Witecka, Akiko Yamamoto, Henryk Dybiec and Wojciech Swieszkowski

    2012-01-01

    Full Text Available Mg alloys with high Al contents have superior corrosion resistance in aqueous environments, but poor cytocompatibility compared to that of pure Mg. We have silanized the cast AZ91 alloy to improve its cytocompatibility using five different silanes: ethyltriethoxysilane (S1, 3-aminopropyltriethoxysilane (S2, 3-isocyanatopyltriethoxysilane (S3, phenyltriethoxysilane (S4 and octadecyltriethoxysilane (S5. The surface hydrophilicity/hydrophobicity was evaluated by water contact angle measurements. X-ray photoelectron analysis was performed to investigate the changes in surface states and chemical composition. All silane reagents increased adsorption of the albumin to the modified surface. In vitro cytocompatibility evaluation revealed that silanization improved cell growth on AZ91 modified by silane S1. Measurement of the concentration of Mg2+ ions released during the cell culture indicated that silanization does not affect substrate degradation.

  13. Stability and activity of lactate dehydrogenase on biofunctional layers deposited by activated vapor silanization (AVS) and immersion silanization (IS)

    Science.gov (United States)

    Calvo, Jorge Nieto-Márquez; Elices, Manuel; Guinea, Gustavo V.; Pérez-Rigueiro, José; Arroyo-Hernández, María

    2017-09-01

    The interaction between surfaces and biological elements, in particular, proteins is critical for the performance of biomaterials and biosensors. This interaction can be controlled by modifying the surface in a process known as biofunctionalization. In this work, the enzyme lactate dehydrogenase (LDH) is used to study the stability of the interaction between a functional protein and amine-functionalized surfaces. Two different functionalization procedures were compared: Activated Vapor Silanization (AVS) and Immersion Silanization (IS). Adsorption kinetics is shown to follow the Langmuir model for AVS-functionalized samples, while IS-functionalized samples show a certain instability if immersed in an aqueous medium for several hours. In turn, the enzymatic activity of LDH is preserved for longer times by using glutaraldehyde as crosslinker between the AVS biofunctional surface and the enzyme.

  14. The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials.

    Science.gov (United States)

    Nassar, Usama; Flores-Mir, Carlos; Heo, Giseon; Torrealba, Ysidora

    2017-06-01

    Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups ( P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.

  15. Rapid determination of main components by means of flame-atomic-absorption spectrometry for chromium, silicon and tungsten in CrSiW materials

    International Nuclear Information System (INIS)

    Mueller, E.; Stahlberg, R.

    1985-01-01

    The application of Flame-Atomic-Absorption Spectrometry (FAAS) for determining chromium, silicon and tungsten in CrSiW materials is described. The FAAS determinations of the main components are shown under optimum conditions. Sufficient precision and reliability have been achieved for routine analysis. The application of a mixture of acids for preparing CrSiW solutions is proposed. The preparation of samples is discussed in detail. Optimum conditions are recommended for determining chromium, silicon and tungsten using one solution only. (orig.) [de

  16. Silicon heterojunction transistor

    International Nuclear Information System (INIS)

    Matsushita, T.; Oh-uchi, N.; Hayashi, H.; Yamoto, H.

    1979-01-01

    SIPOS (Semi-insulating polycrystalline silicon) which is used as a surface passivation layer for highly reliable silicon devices constitutes a good heterojunction for silicon. P- or B-doped SIPOS has been used as the emitter material of a heterojunction transistor with the base and collector of silicon. An npn SIPOS-Si heterojunction transistor showing 50 times the current gain of an npn silicon homojunction transistor has been realized by high-temperature treatments in nitrogen and low-temperature annealing in hydrogen or forming gas

  17. Influence of Containment on the Growth of Silicon-Germanium: A Materials Science Flight Project

    Science.gov (United States)

    Volz, M. P.; Mazuruk, K.; Croell, A.

    2012-01-01

    A series of Ge(1-x)Si(x) crystal growth experiments are planned to be conducted in the Low Gradient Furnace (LGF) onboard the International Space Station. The primary objective of the research is to determine the influence of containment on the processing-induced defects and impurity incorporation in germanium-silicon alloy crystals. A comparison will be made between crystals grown by the normal and "detached" Bridgman methods and the ground-based float zone technique. Crystals grown without being in contact with a container have superior quality to otherwise similar crystals grown in direct contact with a container, especially with respect to impurity incorporation, formation of dislocations, and residual stress in crystals. "Detached" or "dewetted" Bridgman growth is similar to regular Bridgman growth in that most of the melt is in contact with the crucible wall, but the crystal is separated from the wall by a small gap, typically of the order of 10-100 microns. Long duration reduced gravity is essential to test the proposed theory of detached growth. Detached growth requires the establishment of a meniscus between the crystal and the ampoule wall. The existence of this meniscus depends on the ratio of the strength of gravity to capillary forces. On Earth, this ratio is large and stable detached growth can only be obtained over limited conditions. Crystals grown detached on the ground exhibited superior structural quality as evidenced by measurements of etch pit density, synchrotron white beam X-ray topography and double axis X-ray diffraction. The plans for the flight experiments will be described.

  18. Influence of Containment on the Growth of Silicon-Germanium (ICESAGE): A Materials Science ISS Investigation

    Science.gov (United States)

    Volz, M. P.; Mazuruk, K.; Croll, A.

    2014-01-01

    A series of Ge(1-x)Si(x) crystal growth experiments are planned to be conducted in the Low Gradient Furnace (LGF) onboard the International Space Station. The primary objective of the research is to determine the influence of containment on the processinginduced defects and impurity incorporation in germanium-silicon alloy crystals. A comparison will be made between crystals grown by the normal and "detached" Bridgman methods and the ground-based float zone technique. Crystals grown without being in contact with a container have superior quality to otherwise similar crystals grown in direct contact with a container, especially with respect to impurity incorporation, formation of dislocations, and residual stress in crystals. "Detached" or "dewetted" Bridgman growth is similar to regular Bridgman growth in that most of the melt is in contact with the crucible wall, but the crystal is separated from the wall by a small gap, typically of the order of 10-100 microns. Long duration reduced gravity is essential to test the proposed theory of detached growth. Detached growth requires the establishment of a meniscus between the crystal and the ampoule wall. The existence of this meniscus depends on the ratio of the strength of gravity to capillary forces. On Earth, this ratio is large and stable detached growth can only be obtained over limited conditions. Crystals grown detached on the ground exhibited superior structural quality as evidenced by measurements of etch pit density, synchrotron white beam X-ray topography and double axis X-ray diffraction. The plans for the flight experiments will be described.

  19. Porous silicon: some new applications of this material with astonishing properties; Le silicium poreux: nouvelles applications de ce materiau aux proprietes remarquables

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier-Manuel, B. [Laboratoire FEMTO-ST, Dept. MN2S, CNRS UMR 6174, 25 - Besancon (France)

    2009-02-15

    Anodic oxidation of silicon wafer in fluor-hydric acid solution leads to a porous material with surprising properties. Structures at nano-metric scale are source of deep photoluminescence. The very large scale of pore size available and the high specific surface obtained allows optical and microfabrication applications. This paper describes the electrochemical process of this material, some characterization methods, and some new applications in the fields of micro-energy and molecular separation. (author)

  20. Coupling of HDPE/hydroxyapatite composites by silane-based methodologies.

    Science.gov (United States)

    Sousa, R A; Reis, R L; Cunha, A M; Bevis, M J

    2003-06-01

    Several coupling treatments based on silane chemicals were investigated for the development of high density (HDPE)/hydroxyapatite (HA) composites. Two HA powders, sintered HA (HAs) and non sintered HA (HAns), were studied in combination with five silanes, namely y-methacryloxy propyltrimethoxy silane (MEMO), 3-(2-aminoethyl)aminopropyltrimethoxy silane (DAMO), vinyltrimethoxy silane (VTMO), 3-aminopropyltriethoxy silane (AMEO) and trimethoxypropyl silane (PTMO). The HA particles were treated by a dipping in method or by spraying with silane solutions. After drying, the treated powders were compounded with HDPE or HDPE with acrylic acid and/or organic peroxide and subsequently compression molded. The tensile test specimens obtained from the molded plates were tensile tested and their fracture surfaces were observed by scanning electron microscopy (SEM). For the sintered HA (HAs) composites, the most effective coupling treatments concerning stiffness are those based on MEMO and AMEO. The low influence of these coupling procedures on strength is believed to be associated to the low volume fraction and the relatively smooth surface of the used HA particles. For the non-sintered HA (HAns) composites, it was possible to improve significantly both the stiffness and the strength. Amino silanes demonstrated to be highly efficient concerning strength enhancement. The higher effectiveness of the coupling treatments for HAns filled composites is attributed to their higher particle surface area, smaller particle size distribution and expected higher chemical reactivity. For both cases, the improvement in mechanical performance after the coupling treatment is consistent with the enhancement in interfacial adhesion observed by SEM.

  1. Surface modification of basalt with silane coupling agent on asphalt mixture moisture damage

    Energy Technology Data Exchange (ETDEWEB)

    Min, Yahong; Fang, Ying; Huang, Xiaojun; Zhu, Yinhui; Li, Wensheng [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Yuan, Jianmin [College of Materials Engineering, Hunan University, Changsha, 410082 (China); Tan, Ligang [College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082 (China); Wang, Shuangyin [State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wu, Zhenjun, E-mail: wooawt@163.com [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • A new silane coupling agent was synthesized based on KH570. • Basalt surface was modified using the new silane coupling agent. • Chemical bond between basalt and the new silane coupling agent was formed. • Asphalt mixture which used modified basalt show superior water stability. - Abstract: A new silane coupling agent was synthesized based on γ-(methacryloyloxy) propyltrimethoxysilane (KH570). The surface of basalt rocks was modified by KH570 and the new silane coupling agent (NSCA), and the interfacial interaction between silane coupling agent and basalt was also studied. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis showed that the silane coupling agent molecule bound strongly with basalt rocks. Scanning electronic microscopy (SEM) observation showed that a thin layer of coupling agent was formed on the surface of modified basalt. The boiling test and immersion Marshall test confirmed that the moisture sensitivity of basalt modified with the new silane coupling agent increased more significantly than that untreated and treated with KH570. The Retained Marshall Strength of basalt modified with the new coupling agent increased from 71.74% to 87.79% compared with untreated basalt. The results indicated that the new silane coupling agent played an important role in improving the interfacial performance between basalt and asphalt.

  2. Radiation hardness of silicon detectors manufactured on epitaxial material and FZ bulk enriched with oxygen, carbon, tin and platinum

    CERN Document Server

    Ruzin, A; Glaser, M; Lemeilleur, F; Talamonti, R; Watts, S; Zanet, A

    1999-01-01

    Recent results on the radiation hardness of silicon detectors fabricated on epitaxial and float zone bulk silicon enriched by various impurities, such as carbon, oxygen, tin and platinum are reported. A new methodology of measurements of electrical properties of the devices has been utilized in the experiment. It has been shown that in the case of irradiation by protons, oxygen enriched silicon has better radiation hardness than standard float zone silicon. The carbon enriched silicon detectors, on the other hand, exhibited significantly inferior radiation hardness compared to standard detectors. This study shows for the first time, a violation of the widely used normalization technique of the various particle irradiations by NIEL coefficients. The study has been carried out in the framework of the RD48 (ROSE) collaboration, which studies the radiation hardening of silicon detectors. (5 refs).

  3. Physical adsorption vs. chemical binding of undecylenic acid on porous silicon surface: a comparative study of differently functionalized materials

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, J.; Lehto, V.P. [University of Turku (Finland). Department of Physics; Chirvony, V.; Matveeva, E. [Nanophotonics Technology Center, Technical University of Valencia (Spain); Pastor, E.

    2009-07-15

    To imply miscibility to porous silicon (PSi) used for biomedical purposes a number of functionalization methods are employed. In order to distinguish between a non-specific surfactant-like interaction (physical sorption) and chemical binding of unsaturated chemicals (undecylenic acid, UD) to H-terminated PSi surface we studied the two differently treated materials. Differential scanning calorimetry (DSC) and thermogravimetry (TGA), BET and FTIR measurements were performed with the PSi powder samples (n+ doped). Changes in surface area, weight loss, calorific effect and chemical composition that accompanied the thermal treatment have shown that the physisorbed UD molecules undergo a chemical process (binding) with the Si-H{sub x} surface groups at about 150 C in both, N{sub 2} inert atmosphere and in a synthetic air, oxidative atmosphere. Controlled conversion of physically sorbed molecules to the chemically attached ones is discussed with respect to methods of surface modification of PSi materials for increasing their biocompatibility. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Demonstrating the feasibility of monitoring the molecular-level structures of moving polymer/silane interfaces during silane diffusion using SFG.

    Science.gov (United States)

    Chen, Chunyan; Wang, Jie; Loch, Cheryl L; Ahn, Dongchan; Chen, Zhan

    2004-02-04

    In this paper, the feasibility of monitoring molecular structures at a moving polymer/liquid interface by sum frequency generation (SFG) vibrational spectroscopy has been demonstrated. N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (AATM, NH2(CH2)2NH(CH2)3Si(OCH3)3) has been brought into contact with a deuterated poly(methyl methacrylate) (d-PMMA) film, and the interfacial silane structure has been monitored using SFG. Upon initial contact, the SFG spectra can be detected, but as time progresses, the spectral intensity changes and finally disappears. Additional experiments indicate that these silane molecules can diffuse into the polymer film and the detected SFG signals are actually from the moving polymer/silane interface. Our results show that the molecular order of the polymer/silane interface exists during the entire diffusion process and is lost when the silane molecules traverse through the thickness of the d-PMMA film. The loss of the SFG signal is due to the formation of a new disordered substrate/silane interface, which contributes no detectable SFG signal. The kinetics of the diffusion of the silane into the polymer have been deduced from the time-dependent SFG signals detected from the AATM molecules as they diffuse through polymer films of different thickness.

  5. Oxidation and creep behaviour of dense silicon nitride materials with different compositions

    International Nuclear Information System (INIS)

    Ernstberger, U.

    1985-09-01

    The study was intended to yield information on the oxidation and creep behaviour of Si 3 N 4 materials of different composition and microstructure, and produced by different processes. The experiments carried out in a vast temperature and load range showed that the chemical grain boundary composition is the key parameter affecting the materials' high-temperature properties. Significant correlations could be established between oxidation and creep behaviour on the one hand, and between microstructure and the behaviour on the other. (orig./IHOE) [de

  6. GaN growth on silane exposed AlN seed layers

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Zepeda, F. [Posgrado en Fisica de Materiales, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Km. 107 Carret, Tijuana-Ensenada, C.P. 22860, Ensenada, B.C. (Mexico); Contreras, O. [Centro de Ciencias de la Materia Condesada, Universidad Nacional Autonoma de Mexico, Apdo. Postal 356, C.P. 22800, Ensenada, B.C. (Mexico); Dadgar, A.; Krost, A. [Otto-von-Guericke-Universitaet Magdeburg, FNW-IEP, Universitaetsplatz 2, 39106 Magdeburg (Germany)

    2008-07-01

    The microstructure and surface morphology of GaN films grown on AlN seed layers exposed to silane flow has been studied by TEM and AFM. The epilayers were grown on silicon(111) substrates by MOCVD. The AlN seed layer surface was treated at different SiH{sub 4} exposure times prior to the growth of the GaN film. A reduction in the density of threading dislocations is observed in the GaN films and their surface roughness is minimized for an optimal SiH{sub 4} exposure time between 75-90 sec. At this optimal condition a step-flow growth mode of GaN film is predominant. The improvement of the surface and structure quality of the epilayers is observed to be related to an annihilation process of threading dislocations done by SiN{sub x} masking. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Investigations of processes of mixing in fabrication of carbonaceous materials and materials of silicon carbide by means of tracer technique

    International Nuclear Information System (INIS)

    Vagner, K.; Bruchin, F.; Ritter, I.; Grech, T.; Tsimmermann, V.; Ebert, G.

    1979-01-01

    A necessary condition for production of carbonic and SiC materials is providing for good mixing of liquid and solid components. Some experiments have been done by application of the method of radioactive marking of one of the components to be mixed for the purpose of investigation of the mixing process in an installation with capacity up to 2000 kg. Marking by the bromine-82 - naphthalene has been found to be suitable. The state of mixture is characterized by the homogeneity of radioactivity distribution which can be determined by measurement of gamma-radiation of series of samples. The mass of sample is from 1 to 100 g, depending on the volume of mixer. Besides it, fine distribution of components was determined by the contact autoradiography of flat surfaces of samples. The results of investigations give possibility to establish technological time of mixing, to compare different mixers and technologies of mixing as well as to determine behaviour of the mixed components. Recommendations have been developed on standardization of this method. Necessary means of radiation protection have been described [ru

  8. Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

    Directory of Open Access Journals (Sweden)

    Lars Borchardt

    2011-09-01

    Full Text Available For the first time we present the synthesis of CeO2/Si(OC core–shell particles prepared by the miniemulsion technique. The Si(OC core was obtained by means of a polycarbosilane precursor (SMP10, which was subsequently functionalized with ceria and pyrolyzed to the ceramic. The size of these particles could easily be adjusted by varying the surfactants and the surfactant concentration, or by the addition of comonomers. Hence particle sizes ranged from 100 to 1000 nm, tunable by the preparation conditions. All materials were characterized by photon cross correlation spectroscopy, scanning electron microscopy and elemental mapping investigations. Furthermore, first catalytic tests were carried out by temperature programmed oxidation (TPO of methane, and the activity of this material in lowering the onset temperature of methane combustion by 262 K was documented.

  9. Nanocrystalline silicon as the light emitting material of a field emission display device

    International Nuclear Information System (INIS)

    Biaggi-Labiosa, A; Sola, F; Resto, O; Fonseca, L F; Gonzalez-BerrIos, A; Jesus, J De; Morell, G

    2008-01-01

    A nanocrystalline Si-based paste was successfully tested as the light emitting material in a field emission display test device that employed a film of carbon nanofibers as the electron source. Stable emission in the 550-850 nm range was obtained at 16 V μm -1 . This relatively low field required for intense cathodoluminescence (CL) from the PSi paste may lead to longer term reliability of both the electron emitting and the light emitting materials, and to lower power consumption. Here we describe the synthesis, characterization, and analyses of the light emitting nanostructured Si paste and the electron emitting C nanofibers used for building the device, including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The corresponding spectra and field emission curves are also shown and discussed

  10. Mechanical properties of silicone based composites as a temperature insensitive ballistic backing material for quantifying back face deformation.

    Science.gov (United States)

    Edwards, Tara D; Bain, Erich D; Cole, Shawn T; Freeney, Reygan M; Halls, Virginia A; Ivancik, Juliana; Lenhart, Joseph L; Napadensky, Eugene; Yu, Jian H; Zheng, James Q; Mrozek, Randy A

    2018-04-01

    This paper describes a new witness material for quantifying the back face deformation (BFD) resulting from high rate impact of ballistic protective equipment. Accurate BFD quantification is critical for the assessment and certification of personal protective equipment, such as body armor and helmets, and ballistic evaluation. A common witness material is ballistic clay, specifically, Roma Plastilina No. 1 (RP1). RP1 must be heated to nearly 38°C to pass calibration, and used within a limited time frame to remain in calibration. RP1 also exhibits lot-to-lot variability and is sensitive to time, temperature, and handling procedures, which limits the BFD accuracy and reproducibility. A new silicone composite backing material (SCBM) was developed and tested side-by-side with heated RP1 using quasi-static indentation and compression, low velocity impact, spherical projectile penetration, and both soft and hard armor ballistic BFD measurements to compare their response over a broad range of strain rates and temperatures. The results demonstrate that SCBM mimics the heated RP1 response at room temperature and exhibits minimal temperature sensitivity. With additional optimization of the composition and processing, SCBM could be a drop-in replacement for RP1 that is used at room temperature during BFD quantification with minimal changes to the current RP1 handling protocols and infrastructure. It is anticipated that removing the heating requirement, and temperature-dependence, associated with RP1 will reduce test variability, simplify testing logistics, and enhance test range productivity. Published by Elsevier B.V.

  11. Preparation and characterization of flame retardant n-hexadecane/silicon dioxide composites as thermal energy storage materials.

    Science.gov (United States)

    Fang, Guiyin; Li, Hui; Chen, Zhi; Liu, Xu

    2010-09-15

    Flame retardant n-hexadecane/silicon dioxide (SiO(2)) composites as thermal energy storage materials were prepared using sol-gel methods. In the composites, n-hexadecane was used as the phase change material for thermal energy storage, and SiO(2) acted as the supporting material that is fire resistant. In order to further improve flame retardant property of the composites, the expanded graphite (EG) was added in the composites. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD) and scanning electronic microscope (SEM) were used to determine chemical structure, crystalloid phase and microstructure of flame retardant n-hexadecane/SiO(2) composites, respectively. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the n-hexadecane was well dispersed in the porous network of the SiO(2). The DSC results indicated that the melting and solidifying latent heats of the composites are 147.58 and 145.10 kJ/kg when the mass percentage of the n-hexadecane in the composites is 73.3%. The TGA results showed that the loading of the EG increased the charred residue amount of the composites at 700 degrees C, contributing to the improved thermal stability of the composites. It was observed from SEM photographs that the homogeneous and compact charred residue structure after combustion improved the flammability of the composites. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Carbon Nanofiber/3D Nanoporous Silicon Hybrids as High Capacity Lithium Storage Materials.

    Science.gov (United States)

    Park, Hyeong-Il; Sohn, Myungbeom; Kim, Dae Sik; Park, Cheolho; Choi, Jeong-Hee; Kim, Hansu

    2016-04-21

    Carbon nanofiber (CNF)/3D nanoporous (3DNP) Si hybrid materials were prepared by chemical etching of melt-spun Si/Al-Cu-Fe alloy nanocomposites, followed by carbonization using a pitch. CNFs were successfully grown on the surface of 3DNP Si particles using residual Fe impurities after acidic etching, which acted as a catalyst for the growth of CNFs. The resulting CNF/3DNP Si hybrid materials showed an enhanced cycle performance up to 100 cycles compared to that of the pristine Si/Al-Cu-Fe alloy nanocomposite as well as that of bare 3DNP Si particles. These results indicate that CNFs and the carbon coating layer have a beneficial effect on the capacity retention characteristics of 3DNP Si particles by providing continuous electron-conduction pathways in the electrode during cycling. The approach presented here provides another way to improve the electrochemical performances of porous Si-based high capacity anode materials for lithium-ion batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Thermal-Hydraulic Aspects of Changing the Nuclear Fuel-Cladding Materials from Zircaloy to Silicon Carbides

    International Nuclear Information System (INIS)

    Niceno, Bojan; Pouchon, Manuel

    2014-01-01

    The accident in Fukushima has drastically shown the drawbacks of Zircaloy claddings despite their beneficial properties in normal use. The effect of the lack of cooling and the production of hydrogen would not have been so strong if the fuel cladding had not consisted of a zirconium (or metal) alloy. International activities have been started to search for an alternative to Zircaloy, however, still on a limited basis. A project sponsored by Swissnuclear has been conducted at Paul Scherrer Institute (PSI) with the aim to close the gap in knowledge on application of silicon carbides (SiC) as potential replacement for Zircaloys as material for nuclear fuel cladding. The work was interdisciplinary, result of collaboration between different laboratories at PSI, and has focused on SiC cladding material properties, implication of its usage on neutronics and on thermal-hydraulics. This paper summarizes thermal-hydraulic aspects of changing Zircaloy for SiC as the cladding material. The change of cladding material inevitably changes the surface properties thus making a significant impact on boiling curve, and critical heat flux (CHF). Low chemical reactivity of SiC means fewer particles in the flow (less crud), which leads to fewer failures, but also decreases the CHF. Due to differences in physical properties between SiC and Zircaloys, higher brittleness of SiC in particular, might have impact on fuel-rod assembly design, which has direct influence on flow patterns and heat transfer in the fuel assembly. Higher melting (i.e. decomposition) point for SiC means that severe accident management guidelines (SAMG) should have to be re-assessed. Not only would the core degrade later than in the case of conventional fuels, but the production of hydrogen would be quite different as well. All these issues are explored in this work in two steps; first the SiC properties which may have influence on thermal-hydraulics are outlined, then each thermal-hydraulic issues is explained from

  14. Development of technology of complex aluminum-silicon-chrome alloy with utilization of off grade raw materials

    Directory of Open Access Journals (Sweden)

    A. Mekhtiev

    2015-01-01

    Full Text Available Experimental studies on obtaining a complex aluminum-silicon-chrome alloy (FASCh from Karaganda high-ash coals and high-carbon ferrochromefines were carried out. A method for smelting low-carbon ferrochrome using aluminum-silicon-chrome alloy as a reductant is suggested.

  15. Functionalization of titanium surface with chitosan via silanation: 3D CLSM imaging of cell biocompatibility behaviour.

    Science.gov (United States)

    Attik, G N; D'Almeida, M; Toury, B; Grosgogeat, B

    2013-09-16

    Biocompatibility ranks as one of the most important properties of dental materials. One of the criteria for biocompatibility is the absence of material toxicity to cells, according to the ISO 7405 and 10993 recommendations. Among numerous available methods for toxicity assessment; 3-dimensional Confocal Laser Scanning Microscopy (3D CLSM) imaging was chosen because it provides an accurate and sensitive index of living cell behavior in contact with chitosan coated tested implants. The purpose of this study was to investigate the in vitro biocompatibility of functionalized titanium with chitosan via a silanation using sensitive and innovative 3D CLSM imaging as an investigation method for cytotoxicity assessment. The biocompatibility of four samples (controls cells, TA6V, TA6V-TESBA and TA6V-TESBAChitosan) was compared in vitro after 24h of exposure. Confocal imaging was performed on cultured human gingival fibroblast (HGF1) like cells using Live/Dead® staining. Image series were obtained with a FV10i confocal biological inverted system and analyzed with FV10-ASW 3.1 Software (Olympus France). Image analysis showed no cytotoxicity in the presence of the three tested substrates after 24 h of contact. A slight decrease of cell viability was found in contact with TA6V-TESBA with and without chitosan compared to negative control cells. Our findings highlighted the use of 3D CLSM confocal imaging as a sensitive method to evaluate qualitatively and quantitatively the biocompatibility behavior of functionalized titanium with chitosan via a silanation. The biocompatibility of the new functionalized coating to HGF1 cells is as good as the reference in biomedical device implantation TA6V.

  16. Functionalization of magnetic nanoparticles with 3-aminopropyl silane

    International Nuclear Information System (INIS)

    Campelj, Stanislav; Makovec, Darko; Drofenik, Miha

    2009-01-01

    Superparamagnetic maghemite nanoparticles were functionalized with 3-aminopropyl triethoxy silane (APS). The influence of the different experimental parameters (temperature, pH, and reactant concentration) on the efficiency of the APS bonding directly to the maghemite nanoparticles or after their coating with a thin layer of silica was systematically studied. The functionalization was followed with measurements of the ζ-potential and direct measurements of the surface APS concentration on the nanoparticles. The surface concentration of the APS was much higher in the case when the APS was bonded to the silica-coated nanoparticles compared to bonding directly to the surfaces of the iron-oxide nanoparticles.

  17. Electron impact spectroscopy of methane, silane, and germane

    International Nuclear Information System (INIS)

    Dillon, M.A.; Wang, R.G.; Spence, D.

    1985-01-01

    Electronic spectra of the group IV/sub a/ hydrides, i.e., methane (CH 4 ), silane (SiH 4 ), and germane (GeH 4 ) have been investigated by means of electron energy loss spectroscopy in an energy range that includes all single-electron excitation from the valence shell. Electron impact spectra of the three gases recorded using electrons of 200-eV incidence are presented. The conditions employed were chosen to favor the excitation of states by direct scattering and to exclude those transitions requiring an exchange mechanism

  18. Silicon carbide, a ceramic material for the pump technology?; Siliciumcarbid - eine Keramik fuer die Pumpentechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Vitzthum, E. [CeramTec AG, Lauf (Germany). Marketing und Customer Service

    2000-12-01

    Pumping of gases and liquids makes extreme demands on sliding bearings and their seals, especially if the material to be pumped is corrosive or contains abrasive constituents. Wear and corrosion are important economic factors. They shorten the life of machines and systems and cause standstill times and repair cost. All this decides the profitability of pumps and the competitive strength of products. In view of all this, it becomes clear why optimal materials selection is a crucial points in pumps and pumping systems. [German] Beim Foerdern von Gasen und Fluessigkeiten werden extrem hohe Anforderungen an Gleitlager und Gleitringdichtungen in Pumpen gestellt, die im direkten Kontakt mit dem zu foerdernden Medium sind, besonders dann, wenn das Medium korrosiv ist oder abrasive Bestandteile enthaelt. Verschleiss und Korrosion sind wesentliche Wirtschaftsfaktoren. Sie bestimmen die Standzeit von Maschinen und Anlagen, verursachen Betriebsstillstandszeiten und Reparaturkosten. Diese entscheiden ueber die Rentabilitaet von Prozessen und die Wettbewerbsfaehigkeit von Produkten, was eine optimale Auswahl des Werkstoffs auch in Pumpen und Pumpenanlagen unerlaesslich macht. (orig.)

  19. NDE methods for determining the materials properties of silicon carbide plates

    Science.gov (United States)

    Kenderian, Shant; Kim, Yong; Johnson, Eric; Palusinski, Iwona A.

    2009-08-01

    Two types of SiC plates, differing in their manufacturing processes, were interrogated using a variety of NDE techniques. The task of evaluating the materials properties of these plates was a challenge due to their non-uniform thickness. Ultrasound was used to estimate the Young's Modulus and calculate the thickness profile and Poisson's Ratio of the plates. The Young's Modulus profile plots were consistent with the thickness profile plots, indicating that the technique was highly influenced by the non-uniform thickness of the plates. The Poisson's Ratio is calculated from the longitudinal and shear wave velocities. Because the thickness is cancelled out, the result is dependent only on the time of flight of the two wave modes, which can be measured accurately. X-Ray was used to determine if any density variations were present in the plates. None were detected suggesting that the varying time of flight of the acoustic wave is attributed only to variations in the elastic constants and thickness profiles of the plates. Eddy Current was used to plot the conductivity profile. Surprisingly, the conductivity profile of one type of plates varied over a wide range rarely seen in other materials. The other type revealed a uniform conductivity profile.

  20. Dispersion and deagglomerat1on of nano-SiO2 particles with a silane modification reagent in supercritical CO2

    Directory of Open Access Journals (Sweden)

    Stojanović Dušica B.

    2007-01-01

    Full Text Available The supercritical CO2 method was used in order to perform deagglomeration and improve the dispersion of nano-SiO2 particles. γ-Met-hacryloxypropyltrimethoxysilane was used as the surface modification reagent. The conventional method for coating nano-SiO2 particles was used as the comparison method. Considerable improvement of the dispersion and deagglomeration was found using supercritical CO2. Analysis of the TEM micrographs and DLS results showed the reduction of the average size of the agglomerates with the silane coupling reagent. Thermogravimetric analysis (TGA showed that the particles treated in super­critical CO2 were more thermally stable than particles treated by conventional method. Encapsulation of several particles coated with the silane coupling reagent was observed in certain parts of the primary particles. A chemical reaction takes place between the modification reagent, MEMO silane, and active hydroxyl groups on the surface of the nano-SiO2 particles. A larger quantity of MEMO silane reacted using the con­ventional method instead of the supercritical method. On the other hand, the reacted silane molecules were better arranged around the particle surface in the supercritical method because of the formation of covalent or self-assembled structures. Polycondensed structures were preferentially obtained in the conventional method. This was achieved by using supercritical CO2, which has a high solvating power such as organic solvents and physical properties (low viscosity, low surface tension and high diffusion coefficient similar to gases on the other side. These properties enable the sufficient and uniform wettability of nano-SiO2 particle surfaces. These results are important for obtaining nanofillers with improved dispersion and polymer wettability. Such nanofillers can be used to obtain composite materials with considerably improved mechanical characteristics.

  1. Electrically active, doped monocrystalline silicon nanoparticles produced by hot wire thermal catalytic pyrolysis

    CSIR Research Space (South Africa)

    Scriba, MR

    2011-05-01

    Full Text Available Doped silicon nanoparticles have successfully been produced by hot wire thermal catalytic pyrolysis at 40 mbar and a filament temperature of 1800 °C, using a mixture of silane and diborane or phosphine. All particles are monocrystalline with shapes...

  2. Fault-tolerant epoxy-silane coating for corrosion protection of magnesium alloy AZ31

    NARCIS (Netherlands)

    Lamaka, S.V.; Xue, H.B.; Meis, N.N.A.H.; Esteves, A.C.C.; Ferreira, M.G.S.

    2015-01-01

    In this work, a hybrid epoxy-silane coating was developed for corrosion protection of magnesium alloy AZ31. The average thickness of the film produced by dip-coating procedure was 14 µm. The adhesion strength of the epoxy-silane coating to the Mg substrate was evaluated by pull-off tests and was

  3. Silane@TiO2 nanoparticles-driven expeditious synthesis of ...

    Indian Academy of Sciences (India)

    of substituted benzo[4,5]imidazo[1,2-a]chromeno[4,3-d]pyrimidin-6-one by a reaction of ..... mal decomposition of the grafted vinyltriethoxy silane on the TiO2 .... using silane@TiO2 nanoparticles.a. Entry. Ar. Product Time (h) Yield (%)c. M.p. (.

  4. Modification of eucalyptus pulp fiber using silane coupling agents with aliphatic side chains of different length

    Science.gov (United States)

    The objective of this work was to evaluate the effect of three silane coupling agents with different aliphatic chain lengths on the hydrophobicity of eucalyptus pulp fiber. The three silanes coupling agents used (isobutyltrimethoxysilane, methyltrimethoxysilane, and n-octyltriethoxysilane [OTES]) we...

  5. Amorphous and microcrystalline silicon applied in very thin tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schicho, Sandra

    2011-07-28

    wider band gap of the intrinsic absorber and window-p-type doped material was achieved. Higher opencircuit voltages were observed using such materials. Two different types of high band gap amorphous absorber layers with the associated p-doped layers were implemented into very thin tandem cells. An elongation of the light path in the absorber material, which is usually accomplished by using textured front contacts and back reflectors, is crucial for the performance of very thin tandem cells. Periodically patterned aluminum plates, which had shown very good light trapping properties for {mu}c-Si:H single junction solar cells, were suggested as substrates for very thin tandem cells. In comparison to tandem cells on standard substrates, higher short-circuit current densities and quantum efficiencies were observed on Al that indicated good light trapping. However, tandem cells on aluminum plates exhibited much lower open-circuit voltages. Raman measurements revealed a higher crystallinity and compressive stress in the microcrystalline bottom cells deposited on aluminum plates compared to cells deposited on standard substrates under the same deposition conditions. The silane concentration that is applied for the deposition of {mu}c-Si:H influences the crystalline volume fraction in a way that under otherwise constant deposition conditions lower values lead to higher crystalline volume fractions. By means of a sample series for which different silane concentrations were applied the orientation of the cubic silicon crystals and the appearance of stacking faults or twinning in the microcrystalline layers were investigated depending on silane concentration and crystalline volume fraction. For these studies, Raman spectroscopy with two different excitation lasers and X-ray diffraction in Bragg-Brentano and Grazing Incidence geometry were carried out. No preferential orientation of the silicon crystals in the investigated materials was detected by asymmetrical Grazing Incidence XRD

  6. Preliminary study for development of low dose radiation shielding material using liquid silicon and metallic compound

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seo Goo; Lee, Sung Soo [Dept. of Medical Science, Graduate School of Soonchunhyang University, Asan (Korea, Republic of); Han, Su Chul [Div. of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kang, Sung Jin [SoonChunHyang University Hospital, Seoul (Korea, Republic of); Lim, Sung Wook [Graduate school of SeJong University, Seoul (Korea, Republic of)

    2017-09-15

    This study measured and compared the protective clothing using Pb used for shielding in a diagnostic X-ray energy range, and the shielding rates of X-ray fusion shielding materials using Si and TiO{sub 2}. For the experiment, a pad type shielding with a thickness of 1 mm was prepared by mixing Si-TiO{sub 2}, and the X-ray shielding rate was compared with 0.5 mmPb plate of The shielding rate of shielding of 0.5 mmPb plate 95.92%, 85.26 % based on the case of no shielding under each 60kVp, 100kVp tube voltage condition. When the shielding of Si-TiO{sub 2} pad was applied, the shielding rate equal to or greater than 0.5 mmPb plate was obtained at a thickness of 11 mm or more, and the shielding rate of 100% or more was confirmed at a thickness of 13 nn in 60kVp condition. When the shielding of Si-TiO{sub 2} pad was applied, the shielding rate equal to or greater than 0.5 mmPb plate was obtained at a thickness of 17 mm or more, and a shielding rate of 0.5 mmPb plate was observed at a thickness of 23 mm in 100kVp condition. Through the results of this study, We could confirm the possibility of manufacturing radiation protective materials that does not contain lead hazard using various metallic compound and liquid Si. This study shows that possibility of liquid Si and other metallic compound can harmonize easily. Beside, It is flexible and strong to physical stress than Pb obtained radiation protective clothes. But additional studies are needed to increase the shielding rate and reduce the weight.

  7. Exploring novel silicon-containing polymers---From preceramic polymers to conducting polymers with nonlinear optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Yi.

    1991-10-07

    Several new types of silicon-containing preceramic polymers, i.e., poly(diorganosilacetylene) and poly(diorganosilvinylene) have been synthesized with molecular weights from 10,000 to 120,000. These polymers could be thermally converted to SiC with a moderate to high char yields. Ready solubility and good processability made these types of polymers attractive in their applications to ceramics. The thermal polymerization of diethynyldiphenyl-silane, which was reported in 1968 to afford poly(diphenylsilyldiacetylene) via dehydrogenation, was reinvestigated. Spectroscopic studies showed that the polymer had a structure of polyacetylene type not diacetylene. Diphenyldiethynylgermane and a series of diorganodiethynylsilances were synthesized. These could be polymerized in the presence of MoCl{sub 5} or WCl{sub 6} to afford a soluble, violet material with Mw as high as 108,000. 100 refs., 56 figs., 16 tabs.

  8. Biofunctionalized anti-corrosive silane coatings for magnesium alloys.

    Science.gov (United States)

    Liu, Xiao; Yue, Zhilian; Romeo, Tony; Weber, Jan; Scheuermann, Torsten; Moulton, Simon; Wallace, Gordon

    2013-11-01

    Biodegradable magnesium alloys are advantageous in various implant applications, as they reduce the risks associated with permanent metallic implants. However, a rapid corrosion rate is usually a hindrance in biomedical applications. Here we report a facile two step procedure to introduce multifunctional, anti-corrosive coatings on Mg alloys, such as AZ31. The first step involves treating the NaOH-activated Mg with bistriethoxysilylethane to immobilize a layer of densely crosslinked silane coating with good corrosion resistance; the second step is to impart amine functionality to the surface by treating the modified Mg with 3-amino-propyltrimethoxysilane. We characterized the two-layer anticorrosive coating of Mg alloy AZ31 by Fourier transform infrared spectroscopy, static contact angle measurement and optical profilometry, potentiodynamic polarization and AC impedance measurements. Furthermore, heparin was covalently conjugated onto the silane-treated AZ31 to render the coating haemocompatible, as demonstrated by reduced platelet adhesion on the heparinized surface. The method reported here is also applicable to the preparation of other types of biofunctional, anti-corrosive coatings and thus of significant interest in biodegradable implant applications. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. Inhibiting and healing effects of potassium permanganate for silane films

    Energy Technology Data Exchange (ETDEWEB)

    She, Zuxin; Li, Qing, E-mail: liqingswu@yeah.net; Wang, Shaoyin; Luo, Fei; Chen, Funan; Li, Longqin

    2013-07-31

    In this study, the inhibiting and healing effects of potassium permanganate for silane films were investigated, and the optimal mole ratio of MnO{sub 4}{sup −}/Cl{sup −} was also obtained. The inhibiting process and healing mechanism were studied by electrochemical measurements and scanning electron microcopy coupled with energy dispersive spectroscopy. Results demonstrated that the introduction of potassium permanganate to electrolyte could stop the development of corrosion process and the optimal inhibiting mole ratio of MnO{sub 4}{sup −}/Cl{sup −} is 2 × 10{sup −1} with a protective efficiency about 99.24%. According to its high protective efficiency and the nice results of long-term immersion test, potassium permanganate as an inhibitor could prolong the lifetime of silane films and expand its scope of application. - Highlights: • Healing sol–gel film was obtained by adding KMnO{sub 4} into electrolyte. • An optimal inhibitor mole ratio of MnO{sub 4}{sup −}/Cl{sup −} for Si sol–gel was 2 × 10{sup −1}. • The best protective efficiency was approximately 99.24%. • The inhibiting effect may be due to production of insoluble manganese hydroxide/oxide.

  10. Co-implantation of carbon and nitrogen into silicon dioxide for synthesis of carbon nitride materials

    CERN Document Server

    Huang, M B; Nuesca, G; Moore, R

    2002-01-01

    Materials synthesis of carbon nitride has been attempted with co-implantation of carbon and nitrogen into thermally grown SiO sub 2. Following implantation of C and N ions to doses of 10 sup 1 sup 7 cm sup - sup 2 , thermal annealing of the implanted SiO sub 2 sample was conducted at 1000 degree sign C in an N sub 2 ambient. As evidenced in Fourier transform infrared measurements and X-ray photoelectron spectroscopy, different bonding configurations between C and N, including C-N single bonds, C=N double bonds and C=N triple bonds, were found to develop in the SiO sub 2 film after annealing. Chemical composition profiles obtained with secondary ion mass spectroscopy were correlated with the depth information of the chemical shifts of N 1s core-level electrons, allowing us to examine the formation of C-N bonding for different atomic concentration ratios between N and C. X-ray diffraction and transmission electron microscopy showed no sign of the formation of crystalline C sub 3 N sub 4 precipitates in the SiO ...

  11. Effects of silane application on the shear bond strength of ceramic orthodontic brackets to enamel surface

    Directory of Open Access Journals (Sweden)

    Pinandi Sri Pudyani

    2016-12-01

    Full Text Available Background: Fixed orthodontic appliances with ceramic brackets are used frequently to fulfill the aesthetic demand of patient through orthodontic treatment. Ceramic brackets have some weaknesses such as bond strength and enamel surface damage. In high bond strength the risk of damage in enamel surfaces increases after debonding. Purpose: This study aimed to determine the effect of silane on base of bracket and adhesive to shear bond strength and enamel structure of ceramic bracket. Method: Sixteen extracted upper premolars were randomly divided into four groups based on silane or no silane on the bracket base and on the adhesive surface. Design of the base on ceramic bracket in this research was microcrystalline to manage the influence of mechanical interlocking. Samples were tested in shear mode on a universal testing machine after attachment. Following it, adhesive remnant index (ARI scores were used to assess bond failure site. Statistical analysis was performed using a two-way Anova and the Mann-Whitney test. A scanning electron microscope (SEM with a magnification of 2000x was used to observe enamel structure after debonding. Result: Shear bond strength was increased between group without silane and group with silane on the base of bracket (p<0,05. There was no significance different between group without silane and group with silane on adhesive (p<0,05. Conclusion: Application of silane on base of bracket increases shear bond strength, however, application of silane on adhesive site does not increase shear bond strength of ceramic bracket. Most bonding failure occurred at the enamel adhesive interface and damage occurred on enamel structure in group contains silane of ceramic bracket.

  12. Luminescence properties of Ce3+-activated alkaline earth silicon nitride M2Si5N8 (M = Ca, Sr, Ba) materials

    NARCIS (Netherlands)

    Li, Y.Q.; With, de G.; Hintzen, H.T.J.M.

    2006-01-01

    The luminescence properties of Ce3+, Li+ or Na+ co-doped alkaline-earth silicon nitride M2Si5N8 (M=Ca, Sr, Ba) are reported. The solubility of Ce3+ and optical properties of M2-2xCexLixSi5N8 (x0.1) materials have been investigated as function of the cerium concentration by X-ray powder diffraction

  13. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Jing; Sato, Riku [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Aisawa, Sumio, E-mail: aisawa@iwate-u.ac.jp [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Hirahara, Hidetoshi [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Mori, Kunio [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Sulfur Chemical Institute, 210, Collabo MIU, 4-3-5, Ueda, Morioka 020-0066 (Japan)

    2017-08-01

    Highlights: • We modify PA6 surface using silane coupling agent layer of APTMS to link HNBR. • APTMS greatly improved heat resistance of PA6 from 153 °C up to 325 °C. • A PA6/HNBR joined body was obtained, and it exhibits high adhesion strength with cohesive failure. • Chemical structures of the adhesion interfaces of PA6/HNBR were confirmed by Nano-IR. - Abstract: A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

  14. Facile synthesis and stable cycling ability of hollow submicron silicon oxide–carbon composite anode material for Li-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joong-Yeon; Nguyen, Dan Thien [Department of Fine Chemical Engineering & Applied Chemistry, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kang, Joon-Sup [Department of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Song, Seung-Wan, E-mail: swsong@cnu.ac.kr [Department of Fine Chemical Engineering & Applied Chemistry, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2015-06-05

    Highlights: • Hollow submicron SiO{sub 2}–carbon composite material was synthesized using Si{sup 4+}-citrate chelation. • Composite material possessed a homogeneous distribution of SiO{sub 2} and carbon. • Composite electrode delivered ⩾600 mAh/g with a stable cycling stability. • This materials design and synthesis provides a useful platform for scalable production. - Abstract: Advanced SiO{sub 2}–carbon composite anode active material for lithium-ion battery has been synthesized through a simple chelation of silicon cation with citrate in a glyme-based solvent. The resultant composite material demonstrates a homogeneous distribution of constituents over the submicron particles and a unique hollow spherical microstructure, which provides an enhanced electrical conductivity and better accommodation of volume change of silicon during electrochemical charge–discharge cycling, respectively. As a result, the composite electrode exhibits a high cycling stability delivering the capacity retention of 91% at the 100th cycle and discharge capacities of 662–602 mAh/g and coulombic efficiencies of 99.8%. This material synthesis is scalable and cost-effective in preparing various submicron or micron composite electrode materials.

  15. Singlet oxygen sensitizing materials based on porous silicone: photochemical characterization, effect of dye reloading and application to water disinfection with solar reactors.

    Science.gov (United States)

    Manjón, Francisco; Santana-Magaña, Montserrat; García-Fresnadillo, David; Orellana, Guillermo

    2010-06-01

    Photogeneration of singlet molecular oxygen ((1)O(2)) is applied to organic synthesis (photooxidations), atmosphere/water treatment (disinfection), antibiofouling materials and in photodynamic therapy of cancer. In this paper, (1)O(2) photosensitizing materials containing the dyes tris(4,4'-diphenyl-2,2'-bipyridine)ruthenium(II) (1, RDB(2+)) or tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) (2, RDP(2+)), immobilized on porous silicone (abbreviated RDB/pSil and RDP/pSil), have been produced and tested for waterborne Enterococcus faecalis inactivation using a laboratory solar simulator and a compound parabolic collector (CPC)-based solar photoreactor. In order to investigate the feasibility of its reuse, the sunlight-exposed RDP/pSil sensitizing material (RDP/pSil-a) has been reloaded with RDP(2+) (RDP/pSil-r). Surprisingly, results for bacteria inactivation with the reloaded material have demonstrated a 4-fold higher efficiency compared to those of either RDP/pSil-a, unused RDB/pSil and the original RDP/pSil. Surface and bulk photochemical characterization of the new material (RDP/pSil-r) has shown that the bactericidal efficiency enhancement is due to aggregation of the silicone-supported photosensitizer on the surface of the polymer, as evidenced by confocal fluorescence lifetime imaging microscopy (FLIM). Photogenerated (1)O(2) lifetimes in the wet sensitizer-doped silicone have been determined to be ten times longer than in water. These facts, together with the water rheology in the solar reactor and the interfacial production of the biocidal species, account for the more effective disinfection observed with the reloaded photosensitizing material. These results extend and improve the operational lifetime of photocatalytic materials for point-of-use (1)O(2)-mediated solar water disinfection.

  16. Process research of non-cz silicon material. Low cost solar array project, cell and module formation research area

    Science.gov (United States)

    1982-01-01

    Liquid diffusion masks and liquid applied dopants to replace the CVD Silox masking and gaseous diffusion operations specified for forming junctions in the Westinghouse baseline process sequence for producing solar cells from dendritic web silicon were investigated.

  17. Low cost solar array project: Cell and module formation research area. Process research of non-CZ silicon material

    Science.gov (United States)

    1983-01-01

    Meniscus coates tests, back junction formation using a new boron containing liquid, tests of various SiO2 and boron containing liquids, pelletized silicon for replenishment during web growth, and ion implantation compatibility/feasibility study are discussed.

  18. Oxygen defect processes in silicon and silicon germanium

    KAUST Repository

    Chroneos, A.; Sgourou, E. N.; Londos, C. A.; Schwingenschlö gl, Udo

    2015-01-01

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies.

  19. Oxygen defect processes in silicon and silicon germanium

    KAUST Repository

    Chroneos, A.

    2015-06-18

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies.

  20. Silicone metalization

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

    2008-12-09

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  1. Low cost solar array project silicon materials task. Development of a process for high capacity arc heater production of silicon for solar arrays

    Science.gov (United States)

    Fey, M. G.

    1981-01-01

    The experimental verification system for the production of silicon via the arc heater-sodium reduction of SiCl4 was designed, fabricated, installed, and operated. Each of the attendant subsystems was checked out and operated to insure performance requirements. These subsystems included: the arc heaters/reactor, cooling water system, gas system, power system, Control & Instrumentation system, Na injection system, SiCl4 injection system, effluent disposal system and gas burnoff system. Prior to introducing the reactants (Na and SiCl4) to the arc heater/reactor, a series of gas only-power tests was conducted to establish the operating parameters of the three arc heaters of the system. Following the successful completion of the gas only-power tests and the readiness tests of the sodium and SiCl4 injection systems, a shakedown test of the complete experimental verification system was conducted.

  2. Comparison of detailed and reduced kinetics mechanisms of silane oxidation in the basis of detonation wave structure problem

    Science.gov (United States)

    Fedorov, A. V.; Tropin, D. A.; Fomin, P. A.

    2018-03-01

    The paper deals with the problem of the structure of detonation waves in the silane-air mixture within the framework of mathematical model of a nonequilibrium gas dynamics. Detailed kinetic scheme of silane oxidation as well as the newly developed reduced kinetic model of detonation combustion of silane are used. On its basis the detonation wave (DW) structure in stoichiometric silane - air mixture and dependences of Chapman-Jouguet parameters of mixture on stoichiometric ratio between the fuel (silane) and an oxidizer (air) were obtained.

  3. The Effect of Aging and Silanization on the Mechanical Properties of Fumed Silica-based Dental Composite

    Directory of Open Access Journals (Sweden)

    Khaje S

    2015-12-01

    Full Text Available Statement of Problem: Mechanical strength and durability of dental composites are the main topics studied in this field of science today. This study examined fumed silica-based composite as a strong and durable restorative material through flexural and cycling test methods. Objectives: The purpose of this study was to evaluate the effect of silanization, ageing, cycling and hybridizing on mechanical properties of fumed silica-based resin composite. Materials and Methods: Composites were made of light-cured copolymer based on Bisphenol A glycolmethacrylate (Bis-GMA and Triethylene glycoldimethacrylate (TEGDMA at proportion of 50:50 which reinforced by fumed silica filler. For each composite sample, 5 specimen bars were made using Teflon mould (2 x 2 x 25 mm3. The samples with 12 wt% fumed silica (FS were considered as a base line group. The samples were exposed to cyclic cold water (FS-CCW and hot water (FS-CHW. The effect of silanization and adding more filler was studied together with samples containing 12 wt% (FS-S (12, 16 wt% (FS-S (16 and 20 wt% (FS-S (20 fumed silica filler. The filler was silanized with (γ-MPS. The degree of conversion was assessed with Fourier Transform Infra-Red spectroscopy. Flexural properties were evaluated with the Three-Point Bending test. Flexural data were analyzed with Excel software. Hardness was measured with an Atomic Force Microscope (AFM. Results: The degree of conversion of the resin reached 74% within 24 hrs. Salinization allowed more filler to be wetted by resin. Addition of silanized particles from sample FS-S (12 to sample FS-S (20 improved the mechanical strength. Hybridizing fumed silica with nano-silica (FS-N had no significant effect on the strength, but nano-hardness improved greatly. Ageing and cycling had adverse effects on the strength of the sample FS. The flexural strength of FS-CHW was 72% less than FS sample. Conclusions: Sample FS-N with low diluent and filler percentage complied with the

  4. Elite silicon and solar power

    International Nuclear Information System (INIS)

    Yasamanov, N.A.

    2000-01-01

    The article is of popular character, the following issues being considered: conversion of solar energy into electric one, solar batteries in space and on the Earth, growing of silicon large-size crystals, source material problems relating to silicon monocrystals production, outlooks of solar silicon batteries production [ru

  5. A Monte Carlo computer code for evaluating energy loss of 10 keV to 10 MeV ions in amorphous silicon materials

    International Nuclear Information System (INIS)

    Erramli, H.; Elbounagui, O.; Misdaq, M.A.; Merzouki, A.

    2007-01-01

    The basic concepts of a computer simulation code for determining the energy loss of ions in the 10 keV to 10 MeV energy range in amorphous silicon materials were presented and discussed. Data obtained were found in good agreement with those obtained by using a SRIM programme. Electronic and nuclear energy losses were evaluated. Variation of the energy loss as a function of the incident ion energy were studied. This new computer code is a good tool for evaluating stopping powers of various materials for light and heavy ions

  6. Fiscal 1993 R and D project for industrial science and technology. Report on results of R and D on silicon-based high polymer material; 1993 nendo keisokei kobunshi zairyo no kenkyu kaihtsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    R and D was conducted on the silicon-based high polymer that are hoped for superior electronic/optical functions and heat/flame-resistant dynamical properties, for the purpose of establishing fundamental technologies such as molecular design, synthesis, material forming and evaluation method, with the fiscal 1993 results summarized. In the synthesis of electrically conductive silicon-based polymeric materials, a concept of indirect doping was presented, revealing that workability and electrically conductive properties were enhanced by additives. In the synthesis of new silicon-based polymeric materials capable of circuit plotting, studies were made on Si-Si bond forming reaction of alkoxydisilanes as well as on the correlation between polysilane skeleton structure and its property. In the synthesis of new silicon-based polymeric materials having for example a light-emitting function, evaluation was made on synthesis and light emitting property concerning the compound that controlled the silicon skeleton structure. In addition, R and D was conducted on the precision synthesis technology of compounds, on which manifestation of photoelectric conversion function was expected. Further, research was done on unsaturated and high coordination organosilicic compound, functionality of silicon-based high polymer, and synthesis/polymerization of silicon monomer. (NEDO)

  7. Influence of silane coupling agent on microstructure and properties of CCTO-P(VDF-CTFE composites

    Directory of Open Access Journals (Sweden)

    Yang Tong

    2018-04-01

    Full Text Available Influence of the coupling agent on microstructure and dielectric properties of ceramic–polymer composites is systematically studied using CaCu3Ti4O12 (CCTO as the filler, trichloro-(1H,1H,2H,2H-perfluorooctyl-silane (Cl3-silane as coupling agent, and P(VDF-CTFE 88/12mol.% copolymer as the matrix. It is demonstrated that Cl3-silane molecules can be attached onto CCTO surface using a simple process. The experimental results show that coating CCTO with Cl3-silane can improve the microstructure uniformity of the composites due to the good wettability between Cl3-silane and P(VDF-CTFE, which also significantly improves the electric breakdown field of the composites. It is found that the composites using CCTO coated with 1.0wt.% Cl3-silane exhibit a higher dielectric constant with a higher electric breakdown field. For the composites with 15vol.% CCTO that is coated with 1.0wt.% Cl3-silane, an electric breakdown field of more than 240MV/m is obtained with an energy density of more than 4.5J/cm3. It is also experimentally found that the dielectric constant can be used to easily identify the optimized content of coupling agent.

  8. Influence of silane coupling agent on microstructure and properties of CCTO-P(VDF-CTFE) composites

    Science.gov (United States)

    Tong, Yang; Zhang, Lin; Bass, Patrick; Rolin, Terry D.; Cheng, Z.-Y.

    Influence of the coupling agent on microstructure and dielectric properties of ceramic-polymer composites is systematically studied using CaCu3Ti4O12 (CCTO) as the filler, trichloro-(1H,1H,2H,2H-perfluorooctyl)-silane (Cl3-silane) as coupling agent, and P(VDF-CTFE) 88/12mol.% copolymer as the matrix. It is demonstrated that Cl3-silane molecules can be attached onto CCTO surface using a simple process. The experimental results show that coating CCTO with Cl3-silane can improve the microstructure uniformity of the composites due to the good wettability between Cl3-silane and P(VDF-CTFE), which also significantly improves the electric breakdown field of the composites. It is found that the composites using CCTO coated with 1.0wt.% Cl3-silane exhibit a higher dielectric constant with a higher electric breakdown field. For the composites with 15vol.% CCTO that is coated with 1.0wt.% Cl3-silane, an electric breakdown field of more than 240MV/m is obtained with an energy density of more than 4.5J/cm3. It is also experimentally found that the dielectric constant can be used to easily identify the optimized content of coupling agent.

  9. An Atomic Force Microscopy Study of the Interactions Involving Polymers and Silane Networks

    Directory of Open Access Journals (Sweden)

    Rodrigo L. Oréfice

    1998-12-01

    Full Text Available ABSTRACT: Silane coupling agents have been frequently used as interfacial agents in polymer composites to improve interfacial strength and resistance to fluid migration. Although the capability of these agents in improving properties and performance of composites has been reported, there are still many uncertainties regarding the processing-structure-property relationships and the mechanisms of coupling developed by silane agents. In this work, an Atomic Force Microscope (AFM was used to measure interactions between polymers and silica substrates, where silane networks with a series of different structures were processed. The influence of the structure of silane networks on the interactions with polymers was studied and used to determine the mechanisms involved in the coupling phenomenon. The AFM results showed that phenomena such as chain penetration, entanglements, intersegment bonding, chain conformation in the vicinities of rigid surfaces were identified as being relevant for the overall processes of adhesion and adsorption of polymeric chains within a silane network. AFM adhesion curves showed that penetration of polymeric chains through a more open silane network can lead to higher levels of interactions between polymer and silane agents.

  10. Influence of silane content and filler distribution on chemical-mechanical properties of resin composites

    Directory of Open Access Journals (Sweden)

    Tathy Aparecida XAVIER

    2015-01-01

    Full Text Available This study investigated the influence of silane concentration and filler size distribution on the chemical-mechanical properties of experimental composites. Experimental composites with silane contents of 0%, 1% and 3% (in relation to filler mass and composites with mixtures of barium glass particles (median size = 0.4, 1 and 2 μm and nanometric silica were prepared for silane and filler analyses, respectively. The degree of conversion (DC was analyzed by FTIR. Biaxial flexural strength (BFS was tested after 24-h or 90-d storage in water, and fracture toughness, after 24 h. The data were subjected to ANOVA and Tukey’s test (p = 0.05. The DC was not significantly affected by the silane content or filler distribution. The 0% silane group had the lowest immediate BFS, and the 90-d storage time reduced the strength of the 0% and 3% groups. BFS was not affected by filler distribution, and aging decreased the BFS of all the groups. Silanization increased the fracture toughness of both the 1% and 3% groups, similarly. Significantly higher fracture toughness was observed for mixtures with 2 μm glass particles. Based on the results, 3% silane content boosted the initial strength, but was more prone to degradation after water storage. Variations in the filler distribution did not affect BFS, but fracture toughness was significantly improved by increasing the filler size.

  11. Nanoshaving and Nanografting of Water Soluble Polymers on Glass and Silicon Dioxide Surfaces with Applications to DNA Localization

    Science.gov (United States)

    Davis, Brian; Conley, Hiram; Ochoa, Rosie; Hurd, Katie; Linford, Matthew R.; Davis, Robert C.

    2008-10-01

    Chemical surface patterning at the nanoscale is a critical component of chemically directed assembly of nanoscale devices or sensitive biological molecules onto surfaces. Here we present a scanning probe lithography technique that allows for patterning of aqueous polymers on glass or silicon dioxide surfaces. The surfaces were functionalized by covalently bonding a silane monolayer with a known surface charge to either a glass slide or a silicon wafer. A polymer layer less then 2 nm in thickness was electrostatically bound to the silane layer, passivating the functionalized surface. An Atomic Force Microscope (AFM) probe was used to remove a portion of the polymer layer, exposing the functional silane layer underneath. Employing this method we made chemically active submicron regions. These regions were backfilled with a fluorescent polymer and Lambda-DNA. Chemical differentiation was verified through tapping mode AFM and optical fluorescent microscopy. Lines with a pitch as small as 20nm were observed with AFM height and phase mode data.

  12. Scalable Upcycling Silicon from Waste Slicing Sludge for High-performance Lithium-ion Battery Anodes

    International Nuclear Information System (INIS)

    Bao, Qi; Huang, Yao-Hui; Lan, Chun-Kai; Chen, Bing-Hong; Duh, Jenq-Gong

    2015-01-01

    Silicon (Si) has been perceived as a promising next-generation anode material for lithium ion batteries (LIBs) due to its superior theoretical capacity. Despite the natural abundance of this element on Earth, large-scale production of high-purity Si nanomaterials in a green and energy-efficient way is yet to become an industrial reality. Spray-drying methods have been exploited to recover Si particles from low-value sludge produced in the photovoltaic industry, providing a massive and cost-effective Si resource for fabricating anode materials. To address such drawbacks like volume expansion, low electrical and Li + conductivity and unstable solid electrolyte interphase (SEI) formation, the recycled silicon particles have been downsized into nanoscale and shielded by a highly conductive and protective graphene multilayer through high energy ball milling. Cyclic voltammetry and electrochemical impedance spectroscopy measurements have revealed that the graphene wrapping and size reduction approach have significantly improved the electrochemical performance. It delivers an excellent reversible capacity of 1,138 mA h g −1 and a long cycle life with 73% capacity retention over 150 cycles at a high current of 450 mA g −1 . The plentiful waste conversion methodology also provides considerable opportunities for developing additional rechargeable devices, ceramic, powder metallurgy and silane/siloxane products

  13. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Science.gov (United States)

    Sang, Jing; Sato, Riku; Aisawa, Sumio; Hirahara, Hidetoshi; Mori, Kunio

    2017-08-01

    A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

  14. Silicon photonic integration in telecommunications

    Directory of Open Access Journals (Sweden)

    Christopher Richard Doerr

    2015-08-01

    Full Text Available Silicon photonics is the guiding of light in a planar arrangement of silicon-based materials to perform various functions. We focus here on the use of silicon photonics to create transmitters and receivers for fiber-optic telecommunications. As the need to squeeze more transmission into a given bandwidth, a given footprint, and a given cost increases, silicon photonics makes more and more economic sense.

  15. [Investigation of emergency capacities for occupational hazard accidents in silicon solar cell producing enterprises].

    Science.gov (United States)

    Yang, D D; Xu, J N; Zhu, B L

    2016-11-20

    Objective: To investigate and analyze the influential factors of occupational hazard acci-dents, emergency facilities and emergency management in Silicon solar cell producing enterprises, then to pro-vide scientific strategies. Methods: The methods of occupationally healthy field investigating, inspecting of ven-tilation effectiveness, setup of emergency program and wearing chemical suit were used. Results: The mainly occupational hazard accidents factors in the process of Silicon solar cell producing included poisoning chemi-cals, high temperature, onizing radiation and some workplaces. The poisoning chemicals included nitric acid, hydrofluoric acid, sulfuric acid, hydrochloric acid, sodium hydroxide, potassium hydroxide, chlorine, phos-phorus oxychloride, phosphorus pentoxide, nitrogen dioxide, ammonia, silane, and so on; the workplaces in-cluded the area of producing battery slides and auxiliary producing area. Among the nine enterprises, gas detec-tors were installed in special gas supplying stations and sites, but the height, location and alarmvalues of gas detectors in six enterprises were not according with standard criteria; emergency shower and eyewash equip-ment were installed in workplaces with strong corrosive chemicals, but the issues of waste water were not solved; ventilation systems were set in the workplaces with ammonia and silane, but not qualified with part lo-cations and parameters in two enterprises; warehouses with materials of acid, alkali, chemical ammonia and phosphorus oxychloride were equipped with positive - pressure air respirator resuscitator and emergency cabi-nets, but with insufficient quantity in seven enterprises and expiration in part of products. The error rate of set-up emergency program and wearing chemical cloth were 30%~100% and 10%~30%, respectively. Among the nine enterprises, there were emergency rescue plans for dangerous chemical accidents, but without profession-al heatstroke and irradiation accident emergency plans

  16. Electrical Tracking Formation on Silane Epoxy Resin under Various Contaminants

    Directory of Open Access Journals (Sweden)

    NFN Rochmadi

    2013-03-01

    Full Text Available Contamination at the surface of the insulator becomes a serious problem in power system operation, especially for the tropical area. Humidity and rainfall play an important role in wetness by the water at the surface of the insulator, which result in the presence of contaminant and leakage current flowing at the surface of the insulator. This leakage current will generate heat which occurs at the surface of an insulator, so that dry band area will be formed. This ultimately leads to flashover. This paper presents the influence of contaminants to leakage current and formation of electrical tracking at the surface of epoxy resin compound wit silicon rubber. The test was based on Inclined-Planed Tracking method with NH4Cl as contaminants. The industrial and coastal contaminants are used to explain the effect of contaminant at surface tracking process. The flow rate of contaminant was 0.3 ml/min. The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes. It is found that industrial contamination resulting in the smallest surface leakage current is 327.6 mA. Also it is found that coastal contaminant (1420 mS/cm showed the severest damage at surface of test sample. Therefore, special treatment of the sample are needed under these conditions so that the material performance can be improved, especially against the electrical tracking.

  17. Organic coatings silane-based for AZ91D magnesium alloy

    International Nuclear Information System (INIS)

    Hu Junying; Li Qing; Zhong Xiankang; Li Longqin; Zhang Liang

    2010-01-01

    Organic coatings silane-based containing electron withdrawing group or electron donating group have been synthesized and evaluated as prospective surface treatments for AZ91D magnesium alloy by hydrolysis and condensation reaction of the different silanes. Electrochemical tests were employed to confirm the corrosion resistance ability of the two kinds of organic coatings. The results showed that the coating with electron donating group had better corrosion protection performance. On the basis of the spatial configuration and the density of charge of those silanes molecules which was obtained through Gaussian 03 procedure based on B3LYP and density functional theory, combining experiment results, the rational explanation was provided.

  18. Assessment of corrosion resistance of Nd–Fe–B magnets by silanization for orthodontic applications

    Energy Technology Data Exchange (ETDEWEB)

    Fabiano, F., E-mail: ffabiano@unime.it [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, Contrada di Dio, 98166 Messina (Italy); Department of Experimental, Specialized Medical-Surgical and Odontostomatological Sciences, Messina (Italy); Celegato, F. [INRIM Electromagnetism Division, Torino (Italy); Giordano, A. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, Contrada di Dio, 98166 Messina (Italy); Borsellino, C. [Department of Civil Engineering, Computing, Construction, Environmental and Applied Mathematics, Messina (Italy); Bonaccorsi, L.; Calabrese, L. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, Contrada di Dio, 98166 Messina (Italy); Tiberto, P. [INRIM Electromagnetism Division, Torino (Italy); Cordasco, G.; Matarese, G. [Department of Experimental, Specialized Medical-Surgical and Odontostomatological Sciences, Messina (Italy); Fabiano, V. [Department of Civil Engineering, Computing, Construction, Environmental and Applied Mathematics, Messina (Italy); Department of Experimental, Specialized Medical-Surgical and Odontostomatological Sciences, Messina (Italy); Azzerboni, B. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, Contrada di Dio, 98166 Messina (Italy)

    2014-02-15

    Nd–Fe–B permanent magnets are characterised by excellent magnetic properties. However, being extremely vulnerable to the attack of both climate and corrosive environments, their applications are limited. This paper describes how, at different thicknesses of N-propyl-trimetoxy-silane, the coating affects the magnetic force of nickel plated magnets. We also investigate if the corrosion resistance of silanized Nd–Fe–B magnets increases in mildly corrosive environments by immersing them in a synthetic saliva solution. It was found that the silanization treatment does not affect the strength of the magnetic force and provide an enhancement of the corrosion resistance of the substrate.

  19. Assessment of corrosion resistance of Nd-Fe-B magnets by silanization for orthodontic applications

    Science.gov (United States)

    Fabiano, F.; Celegato, F.; Giordano, A.; Borsellino, C.; Bonaccorsi, L.; Calabrese, L.; Tiberto, P.; Cordasco, G.; Matarese, G.; Fabiano, V.; Azzerboni, B.

    2014-02-01

    Nd-Fe-B permanent magnets are characterised by excellent magnetic properties. However, being extremely vulnerable to the attack of both climate and corrosive environments, their applications are limited. This paper describes how, at different thicknesses of N-propyl-trimetoxy-silane, the coating affects the magnetic force of nickel plated magnets. We also investigate if the corrosion resistance of silanized Nd-Fe-B magnets increases in mildly corrosive environments by immersing them in a synthetic saliva solution. It was found that the silanization treatment does not affect the strength of the magnetic force and provide an enhancement of the corrosion resistance of the substrate.

  20. Various Effects of Sandblasting of Dental Restorative Materials.

    Directory of Open Access Journals (Sweden)

    Goro Nishigawa

    Full Text Available Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials.We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC group and non-ultrasonic cleaning (NUSC group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength.For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group.Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.

  1. Initial and long-term bond strengths of one-step self-etch adhesives with silane coupling agent to enamel-dentin-composite in combined situation.

    Science.gov (United States)

    Mamanee, Teerapong; Takahashi, Masahiro; Nakajima, Masatoshi; Foxton, Richard M; Tagami, Junji

    2015-01-01

    This study evaluated the effect of adding silane coupling agent on initial and long-term bond strengths of one-step self-etch adhesives to enamel-dentin-composite in combined situation. Cervical cavities were prepared on extracted molars and filled with Clearfil AP-X. After water-storage for one-week, the filled teeth were sectioned in halves to expose enamel, dentin and composite surfaces and then enamel-dentin-composite surface was totally applied with one of adhesive treatments (Clearfil SE One, Clearfil SE One with Clearfil Porcelain Bond Activator, Beautibond Multi, Beautibond Multi with Beautibond Multi PR Plus and Scotchbond Universal). After designed period, micro-shear bond strengths (µSBSs) to each substrate were determined. For each period of water-storage, additive silane treatments significantly increased µSBS to composite (penamel (p>0.05). Moreover, the stability of µSBS was depended on materials and substrates used.

  2. Characteristics of MOSFETs fabricated in silicon-on-insulator material formed by high-dose oxygen ion implantation

    International Nuclear Information System (INIS)

    Lam, H.W.; Pinizzotto, R.F.; Yuan, H.T.; Bellavance, D.W.

    1981-01-01

    By implanting a dose of 6 x 10 17 cm -2 of 32 O 2 + at 300 keV into a silicon wafer, a buried oxide layer is formed. Crystallinity of the silicon layer above the buried oxide layer is maintained by applying a high (>200 0 C) substrate temperature during the ion implantation process. A two-step anneal cycle is found to be adequate to form the insulating buried oxide layer and to repair the implantation damage in the silicon layer on top of the buried oxide. A surface electron mobility as high as 710 cm 2 /Vs has been measured in n-channel MOSFETs fabricated in a 0.5 μm-thick epitaxial layer grown on the buried oxide wafer. A minimum subthreshold current of about 10 pA per micron of channel width at Vsub(DS)=2 V has been measured. (author)

  3. Wear characteristics of TiO[sub 2] coating and silicon carbide alloyed layer on Ti-6Al-4V material

    Energy Technology Data Exchange (ETDEWEB)

    Karamis, M.B. (Dept. of Mechanical Engineering, Erciyes Univ., Kayseri (Turkey))

    1992-08-14

    Wear properties of Ti-6Al-4V material (IMI-318) TiO[sub 2] coated and electron beam alloyed with silicon carbide were tested. Thickness of oxide coating, alloying conditions and properties of the alloyed layer such as hardness, layer thickness and microstructure are described. Wear tests were carried out on a general-purpose wear machine by using a disc-disc sample configuration under lubricated conditions. Counterface materials to oxide-coated and to surface-alloyed specimens were plasma-nitrided AISI 51100 and hardened AISI 4140 respectively. The resulting weight loss and wear resistance were monitored as a function of sliding distance and applied load. Although the electron beam alloying improved the wear resistance of Ti-6Al-4V material, the oxide coatings on the material were not resistant to wear. (orig.).

  4. Reactivity of sulfide-containing silane toward boehmite and in situ modified rubber/boehmite composites by the silane

    Science.gov (United States)

    Lin, Tengfei; Zhu, Lixin; Chen, Weiwei; Wu, Siwu; Guo, Baochun; Jia, Demin

    2013-09-01

    The silanization reaction between boehmite (BM) nanoplatelets and bis-[3-(triethoxysilyl)-propyl]-tetrasulfide (TESPT) was characterized in detail. Via such modification process, the grafted sulfide moieties on the BM endow reactivity toward rubber and substantially improved hydrophobicity for BM. Accordingly, TESPT was employed as in situ modifier for the nitrile rubber (NBR)/BM compounds to improve the mechanical properties of the reinforced vulcanizates. The effects of BM content and in situ modification on the mechanical properties, curing characteristics and morphology were investigated. BM was found to be effective in improving the mechanical performance of NBR vulcanizates. The NBR/BM composites could be further strengthened by the incorporation of TESPT. The interfacial adhesion of NBR/BM composites was obviously improved by the addition of TESPT. The substantially improved mechanical performance was correlated to the interfacial reaction and the improved dispersion of BM in rubber matrix.

  5. Luminescence of porous silicon doped by erbium

    International Nuclear Information System (INIS)

    Bondarenko, V.P.; Vorozov, N.N.; Dolgij, L.N.; Dorofeev, A.M.; Kazyuchits, N.M.; Leshok, A.A.; Troyanova, G.N.

    1996-01-01

    The possibility of the 1.54 μm intensive luminescence in the silicon dense porous layers, doped by erbium, with various structures is shown. Low-porous materials of both porous type on the p-type silicon and porous silicon with wood-like structure on the n + type silicon may be used for formation of light-emitting structures

  6. Designing high performance precursors for atomic layer deposition of silicon oxide

    Energy Technology Data Exchange (ETDEWEB)

    Mallikarjunan, Anupama, E-mail: mallika@airproducts.com; Chandra, Haripin; Xiao, Manchao; Lei, Xinjian; Pearlstein, Ronald M.; Bowen, Heather R.; O' Neill, Mark L. [Air Products and Chemicals, Inc., 1969 Palomar Oaks Way, Carlsbad, California 92011 (United States); Derecskei-Kovacs, Agnes [Air Products and Chemicals, Inc., 7201 Hamilton Blvd., Allentown, Pennsylvania 18195 (United States); Han, Bing [Air Products and Chemicals, Inc., 2 Dongsanhuan North Road, Chaoyang District, Beijing 100027 (China)

    2015-01-15

    Conformal and continuous silicon oxide films produced by atomic layer deposition (ALD) are enabling novel processing schemes and integrated device structures. The increasing drive toward lower temperature processing requires new precursors with even higher reactivity. The aminosilane family of precursors has advantages due to their reactive nature and relative ease of use. In this paper, the authors present the experimental results that reveal the uniqueness of the monoaminosilane structure [(R{sub 2}N)SiH{sub 3}] in providing ultralow temperature silicon oxide depositions. Disubstituted aminosilanes with primary amines such as in bis(t-butylamino)silane and with secondary amines such as in bis(diethylamino)silane were compared with a representative monoaminosilane: di-sec-butylaminosilane (DSBAS). DSBAS showed the highest growth per cycle in both thermal and plasma enhanced ALD. These findings show the importance of the arrangement of the precursor's organic groups in an ALD silicon oxide process.

  7. Characterization of amorphous silicon films by Rutherford backscattering spectrometry. [1. 5-MeV Ho/sup +/

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, K; Imura, T; Iwami, M; Hiraki, A [Osaka Univ., Suita (Japan). Dept. of Electrical Engineering; Satou, M [Government Industrial Research Inst., Osaka, Ikeda (Japan); Fujimoto, F [Tokyo Univ. (Japan). Coll. of General Education; Hamakawa, Y [Osaka Univ., Toyonaka (Japan). Faculty of Engineering Science; Minomura, S [Tokyo Univ. (Japan). Inst. for Solid State Physics; Tanaka, K [Electrotechnical Lab., Tanashi, Tokyo (Japan)

    1980-01-01

    Rutherford backscattering spectrometry (RBS) was applied to the characterization of amorphous silicon films prepared by glow discharge in silane, tetrode- and diode-sputterings of silicon target in ambient argon or hydrogen diluted by argon. This method was able to detect at least 5 at.% hydrogen atoms in amorphous silicon through the change of stopping power. Hydrogen content in films made by glow discharge at the substrate temperature 25/sup 0/C to 300/sup 0/C and at 2 torr of silane gas varied from 50% to 20%. A strong trend was found for oxygen to dissolve into films: Films produced by diode sputtering in argon gas with higher pressure than 3 x 10/sup -2/ torr absorbed oxygen. The potential and fitness of the RBS method for the characterization of amorphous silicon films are emphasized and demonstrated.

  8. Nonlinear silicon photonics

    Science.gov (United States)

    Borghi, M.; Castellan, C.; Signorini, S.; Trenti, A.; Pavesi, L.

    2017-09-01

    Silicon photonics is a technology based on fabricating integrated optical circuits by using the same paradigms as the dominant electronics industry. After twenty years of fervid development, silicon photonics is entering the market with low cost, high performance and mass-manufacturable optical devices. Until now, most silicon photonic devices have been based on linear optical effects, despite the many phenomenologies associated with nonlinear optics in both bulk materials and integrated waveguides. Silicon and silicon-based materials have strong optical nonlinearities which are enhanced in integrated devices by the small cross-section of the high-index contrast silicon waveguides or photonic crystals. Here the photons are made to strongly interact with the medium where they propagate. This is the central argument of nonlinear silicon photonics. It is the aim of this review to describe the state-of-the-art in the field. Starting from the basic nonlinearities in a silicon waveguide or in optical resonator geometries, many phenomena and applications are described—including frequency generation, frequency conversion, frequency-comb generation, supercontinuum generation, soliton formation, temporal imaging and time lensing, Raman lasing, and comb spectroscopy. Emerging quantum photonics applications, such as entangled photon sources, heralded single-photon sources and integrated quantum photonic circuits are also addressed at the end of this review.

  9. Confined high-pressure chemical deposition of hydrogenated amorphous silicon.

    Science.gov (United States)

    Baril, Neil F; He, Rongrui; Day, Todd D; Sparks, Justin R; Keshavarzi, Banafsheh; Krishnamurthi, Mahesh; Borhan, Ali; Gopalan, Venkatraman; Peacock, Anna C; Healy, Noel; Sazio, Pier J A; Badding, John V

    2012-01-11

    Hydrogenated amorphous silicon (a-Si:H) is one of the most technologically important semiconductors. The challenge in producing it from SiH(4) precursor is to overcome a significant kinetic barrier to decomposition at a low enough temperature to allow for hydrogen incorporation into a deposited film. The use of high precursor concentrations is one possible means to increase reaction rates at low enough temperatures, but in conventional reactors such an approach produces large numbers of homogeneously nucleated particles in the gas phase, rather than the desired heterogeneous deposition on a surface. We report that deposition in confined micro-/nanoreactors overcomes this difficulty, allowing for the use of silane concentrations many orders of magnitude higher than conventionally employed while still realizing well-developed films. a-Si:H micro-/nanowires can be deposited in this way in extreme aspect ratio, small-diameter optical fiber capillary templates. The semiconductor materials deposited have ~0.5 atom% hydrogen with passivated dangling bonds and good electronic properties. They should be suitable for a wide range of photonic and electronic applications such as nonlinear optical fibers and solar cells. © 2011 American Chemical Society

  10. Study of thermal stability of (3-aminopropyl)trimethoxy silane-grafted titanate nanotubes for application as nanofillers in polymers.

    Science.gov (United States)

    Plodinec, Milivoj; Gajović, Andreja; Iveković, Damir; Tomašić, Nenad; Zimmermann, Boris; Macan, Jelena; Haramina, Tatjana; Su, D S; Willinger, Marc

    2014-10-31

    Protonated titanate nanotubes (TiNT-H) were surface-modified with (3-aminopropyl)trimethoxy silane (APTMS) by a novel method suitable for the syntheses of large amounts of materials at a low cost. The usage of prepared nanotubes for polymer reinforcement was studied. Since the thermal stability of the nanofiller was important to preserve its functional properties, its stability was studied by in situ high-temperature measurements. The most thermally stable nanotubes were silanized for 20 min and used for the preparation of epoxy-based nanocomposites. The nanofiller formed smaller (a few hundred nm) and larger (a few μm) aggregates in the polymer matrix, and the amount of aggregates increased as the nanofiller content increased. The APTMS-modified titanate nanotubes bonded well with the epoxy matrix since amine groups on the TiNT's surface can react with an epoxy group to form covalent bonds between the matrix and the nanofiller. A very small addition (0.19-1.52 wt%) of the nanotubes significantly increased the glass transition temperature and the modulus in the rubbery state of the epoxy-based polymer. Smaller nanofiller content leads to a larger increase in these parameters and therefore better dynamic mechanical properties due to the smaller amount of large aggregates. APTMS-modified titanate nanotubes have proven to be a promising nanofiller in epoxy-based nanocomposites.

  11. Study of thermal stability of (3-aminopropyl)trimethoxy silane-grafted titanate nanotubes for application as nanofillers in polymers

    International Nuclear Information System (INIS)

    Plodinec, Milivoj; Gajović, Andreja; Iveković, Damir; Tomašić, Nenad; Zimmermann, Boris; Macan, Jelena; Haramina, Tatjana; Su, D S; Willinger, Marc

    2014-01-01

    Protonated titanate nanotubes (TiNT-H) were surface-modified with (3-aminopropyl)trimethoxy silane (APTMS) by a novel method suitable for the syntheses of large amounts of materials at a low cost. The usage of prepared nanotubes for polymer reinforcement was studied. Since the thermal stability of the nanofiller was important to preserve its functional properties, its stability was studied by in situ high-temperature measurements. The most thermally stable nanotubes were silanized for 20 min and used for the preparation of epoxy-based nanocomposites. The nanofiller formed smaller (a few hundred nm) and larger (a few μm) aggregates in the polymer matrix, and the amount of aggregates increased as the nanofiller content increased. The APTMS-modified titanate nanotubes bonded well with the epoxy matrix since amine groups on the TiNT’s surface can react with an epoxy group to form covalent bonds between the matrix and the nanofiller. A very small addition (0.19–1.52 wt%) of the nanotubes significantly increased the glass transition temperature and the modulus in the rubbery state of the epoxy-based polymer. Smaller nanofiller content leads to a larger increase in these parameters and therefore better dynamic mechanical properties due to the smaller amount of large aggregates. APTMS-modified titanate nanotubes have proven to be a promising nanofiller in epoxy-based nanocomposites. (paper)

  12. Characterization of silane reduced CVD tungsten films with respect to silicon content

    International Nuclear Information System (INIS)

    Suzuki, M.; Kobayashi, N.; Makai, K.

    1990-01-01

    Tungsten (W) films grown by LPCVD using WF 6 and SiH 4 are characterized with respect to Si content ([Si]) in the film. The Si content was influenced by the deposition temperature as well as the flow ratio of WF 6 /SiH 4 . The electrical resistance, film stress, and film composition of as-deposited films are categorized by [Si] into three groups: [Si] ≤ 2 atm%, 2 ≤ [Si] 40 atm%. When [Si] ≤ 2 atm%, the electrical resistance is almost proportional to [Si], and it is mainly determined by the impurity scattering of Si. In this [Si] region, W can be selectively deposited on Si. On the other hand, when 2 ≤ [Si] 20-40 atm%, the electrical resistance is only slightly affected by Si content, and its temperature dependence is peculiar to semiconductors. When [Si] > 40 atm%, the microcrystals of WSi 2 begins to form in the film

  13. A compilation of silicon, rare earth element and twenty-one other trace element concentrations in the natural river water reference material SLRS-5 (NRC-CNRC)

    International Nuclear Information System (INIS)

    Yeghicheyan, Delphine; Cloquet, Christophe; Bossy, Cecile; Bouhnik Le Coz, Martine; Douchet, Chantal; Granier, Guy; Heimburger, Alexie; Losno, Remi; Lacan, Francois; Labatut, Marie; Pradoux, Catherine; Lanzanova, Aurelie; Candaudap, Frederic; Chmeleff, Jerome; Rousseau, Tristan C.C.; Seidel, Jean-Luc; Delpoux, Sophie; Tharaud, Mickael; Sivry, Yann; Sonke, Jeroen E.

    2013-01-01

    The natural river water certified reference material SLRS-5 (NRC-CNRC) was routinely analysed in this study for major and trace elements by ten French laboratories. Most of the measurements were made using ICP-MS. Because no certified values are assigned by NRC-CNRC for silicon and 35 trace element concentrations (rare earth elements, Ag, B, Bi, Cs, Ga, Ge, Li, Nb, P, Rb, Rh, Re, S, Sc, Sn, Th, Ti, Tl, W, Y and Zr), or for isotopic ratios, we provide a compilation of the concentrations and related uncertainties obtained by the participating laboratories. Strontium isotopic ratios are also given. (authors)

  14. Hydrogen in amorphous silicon

    International Nuclear Information System (INIS)

    Peercy, P.S.

    1980-01-01

    The structural aspects of amorphous silicon and the role of hydrogen in this structure are reviewed with emphasis on ion implantation studies. In amorphous silicon produced by Si ion implantation of crystalline silicon, the material reconstructs into a metastable amorphous structure which has optical and electrical properties qualitatively similar to the corresponding properties in high-purity evaporated amorphous silicon. Hydrogen studies further indicate that these structures will accomodate less than or equal to 5 at.% hydrogen and this hydrogen is bonded predominantly in a monohydride (SiH 1 ) site. Larger hydrogen concentrations than this can be achieved under certain conditions, but the excess hydrogen may be attributed to defects and voids in the material. Similarly, glow discharge or sputter deposited amorphous silicon has more desirable electrical and optical properties when the material is prepared with low hydrogen concentration and monohydride bonding. Results of structural studies and hydrogen incorporation in amorphous silicon were discussed relative to the different models proposed for amorphous silicon

  15. Preparation and properties of lauric acid/silicon dioxide composites as form-stable phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Fang Guiyin; Li Hui; Liu Xu

    2010-01-01

    Form-stable lauric acid (LA)/silicon dioxide (SiO 2 ) composite phase change materials were prepared using sol-gel methods. The LA was used as the phase change material for thermal energy storage, with the SiO 2 acting as the supporting material. The structural analysis of these form-stable LA/SiO 2 composite phase change materials was carried out using Fourier transformation infrared spectroscope (FT-IR). The microstructure of the form-stable composite phase change materials was observed by a scanning electronic microscope (SEM). The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the LA was well dispersed in the porous network of SiO 2 . The DSC results indicated that the melting latent heat of the form-stable composite phase change material is 117.21 kJ kg -1 when the mass percentage of the LA in the SiO 2 is 64.8%. The results of the TGA showed that these materials have good thermal stability. The form-stable composite phase change materials can be used for thermal energy storage in waste heat recovery and solar heating systems.

  16. Silicon oxynitride based photonics

    NARCIS (Netherlands)

    Worhoff, Kerstin; Klein, E.J.; Hussein, M.G.; Driessen, A.; Marciniak, M.; Jaworski, M.; Zdanowicz, M.

    2008-01-01

    Silicon oxynitride is a very attractive material for integrated optics. Besides possessing excellent optical properties it can be deposited with refractive indices varying over a wide range by tuning the material composition. In this contribution we will summarize the key properties of this material

  17. Evaluación de dos silanos en compuestos deetilenvinilacetato y harina TelinneMonspessulana//Evaluation of two silanes in ethylenevinylacetate and TelinneMonspessulana flour compounds

    Directory of Open Access Journals (Sweden)

    Oscar Buitrago-Suescun

    2015-09-01

    Full Text Available Se realizó un estudio comparativo del efecto que produce la adición de agentes de acoplamiento tipo silanovinyltrimethoxysilano y 3-aminopropiltrietoxisilano sobre la mezcla de etilenvinilacetato con harina de TelinneMonspessulana. La incorporación de agentes de acoplamiento se hizo de manera directa sobre la mezcla empleando harina sin tratar y mercerizada. También se hicieron ensayos mezclando etilenvinilacetatoy harina injertada previamente con cada uno de los silanos. Los compuestos fueron sometidos a ensayos de tensión con el fin de evaluar los agentes de acoplamiento. Se encontró que la adición delsilano amino durante el mezclado de los compuestos aumentó la resistencia a la tracción, siendo un importante resultado pues estos son materiales livianos aplicables en la industria de construcción y automotriz.Palabras claves: etilenvinilacetato, harina telinnemonspessulana, compuestos de plástico con madera, agente de acoplamiento silano, viniltrimetoxisilano, aminopropiltrietoxisilano._____________________________________________________________________________AbstractA comparative study the effect of the addition of silane coupling agents, vinyltrimethoxysilane and 3-aminopropyltriethoxysilane on ethylenevinylacetate and Telinnemonspessulana flour composites was performed. The silane coupling agents were added in the mixing stage of ethylene vinyl acetate and wood flour (untreated and mercerized. Tests were also made by mixing ethylenevinylacetate with previously grafted wood flour. Flour graft was performed with vinyltrimethoxysilane and 3-aminopropiltrietoxisilano. The compounds were tested for tensile testing to evaluate the coupling agents. It was found that the addition of amino-silane during mixing increased tensile strength, being this an important result since these are lightweight materials that can be used in the construction and automobile industry. Key words: ethylene-vinyl acetate, telinnemonspessulana flour, wood

  18. Preparation and characterization of ultra-thin amphiphobic coatings on silicon wafers

    International Nuclear Information System (INIS)

    Mou, Chun-Yueh; Yuan, Wei-Li; Shih, Chih-Hsin

    2013-01-01

    Fluorine-based amphiphobic coatings have been widely used in commercial domestic utensils and textiles to repel water and oil contaminants. However, few reports from the literature survey have discussed the effects on amphiphobicity of the nano- to micro-scale surface features of such a coating. In this research thin amphiphobic epoxy coatings based on a mixture of bisphenol A diglycidyl ether, tetraethylorthosilicate (TEOS), and a particular alkoxy silane with fluorinated side chains (F-silane) are deposited on silicon wafers. Film amphiphobicity is characterized by the measurement of water and oil contact angles of the coating. Film morphology is revealed in the scanned images using atomic force microscopy. The deposited films free of F-silane are about 10 nm thick. When a small amount of F-silane was firstly added, the water and oil contact angles of the deposited films jumped up to 107° and 69° respectively and then flattened out with increased F-silane. Water droplets gave an average plateau contact angle about 110°, while vegetable oil ones, 40°. It was noted that there is a dramatic decrease in the lyophobicity causing a reduction in contact angles. However, surface lyophobicity also depends on sub-microscopic surface structures. In addition, by increasing TEOS, it was shown that the formed silica sols or granules were helpful in enhancing the mechanical strength along with retaining the lyophobicity of the film. - Highlights: • Epoxy ultrathin films about 10 nm thick deposited on silicon wafer. • Nominal fluorinated silane added to epoxy coatings for amphiphobicity. • Surface lyophobicity retained by sub-micrometer granules in ultrathin coatings. • Film hardness improved by adding tetraethylorthosilicate

  19. Preparation and characterization of ultra-thin amphiphobic coatings on silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Mou, Chun-Yueh, E-mail: cymou165@gmail.com; Yuan, Wei-Li; Shih, Chih-Hsin

    2013-06-30

    Fluorine-based amphiphobic coatings have been widely used in commercial domestic utensils and textiles to repel water and oil contaminants. However, few reports from the literature survey have discussed the effects on amphiphobicity of the nano- to micro-scale surface features of such a coating. In this research thin amphiphobic epoxy coatings based on a mixture of bisphenol A diglycidyl ether, tetraethylorthosilicate (TEOS), and a particular alkoxy silane with fluorinated side chains (F-silane) are deposited on silicon wafers. Film amphiphobicity is characterized by the measurement of water and oil contact angles of the coating. Film morphology is revealed in the scanned images using atomic force microscopy. The deposited films free of F-silane are about 10 nm thick. When a small amount of F-silane was firstly added, the water and oil contact angles of the deposited films jumped up to 107° and 69° respectively and then flattened out with increased F-silane. Water droplets gave an average plateau contact angle about 110°, while vegetable oil ones, 40°. It was noted that there is a dramatic decrease in the lyophobicity causing a reduction in contact angles. However, surface lyophobicity also depends on sub-microscopic surface structures. In addition, by increasing TEOS, it was shown that the formed silica sols or granules were helpful in enhancing the mechanical strength along with retaining the lyophobicity of the film. - Highlights: • Epoxy ultrathin films about 10 nm thick deposited on silicon wafer. • Nominal fluorinated silane added to epoxy coatings for amphiphobicity. • Surface lyophobicity retained by sub-micrometer granules in ultrathin coatings. • Film hardness improved by adding tetraethylorthosilicate.

  20. Radiation resistant passivation of silicon solar cells

    International Nuclear Information System (INIS)

    Swanson, R.M.; Gan, J.Y.; Gruenbaum, P.E.

    1991-01-01

    This patent describes a silicon solar cell having improved stability when exposed to concentrated solar radiation. It comprises a body of silicon material having a major surface for receiving radiation, a plurality of p and n conductivity regions in the body for collecting electrons and holes created by impinging radiation, and a passivation layer on the major surface including a first layer of silicon oxide in contact with the body and a polycrystalline silicon layer on the first layer of silicon oxide

  1. Periodically poled silicon

    Science.gov (United States)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

    2010-02-01

    Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

  2. Nanostructured silicon for thermoelectric

    Science.gov (United States)

    Stranz, A.; Kähler, J.; Waag, A.; Peiner, E.

    2011-06-01

    Thermoelectric modules convert thermal energy into electrical energy and vice versa. At present bismuth telluride is the most widely commercial used material for thermoelectric energy conversion. There are many applications where bismuth telluride modules are installed, mainly for refrigeration. However, bismuth telluride as material for energy generation in large scale has some disadvantages. Its availability is limited, it is hot stable at higher temperatures (>250°C) and manufacturing cost is relatively high. An alternative material for energy conversion in the future could be silicon. The technological processing of silicon is well advanced due to the rapid development of microelectronics in recent years. Silicon is largely available and environmentally friendly. The operating temperature of silicon thermoelectric generators can be much higher than of bismuth telluride. Today silicon is rarely used as a thermoelectric material because of its high thermal conductivity. In order to use silicon as an efficient thermoelectric material, it is necessary to reduce its thermal conductivity, while maintaining high electrical conductivity and high Seebeck coefficient. This can be done by nanostructuring into arrays of pillars. Fabrication of silicon pillars using ICP-cryogenic dry etching (Inductive Coupled Plasma) will be described. Their uniform height of the pillars allows simultaneous connecting of all pillars of an array. The pillars have diameters down to 180 nm and their height was selected between 1 micron and 10 microns. Measurement of electrical resistance of single silicon pillars will be presented which is done in a scanning electron microscope (SEM) equipped with nanomanipulators. Furthermore, measurement of thermal conductivity of single pillars with different diameters using the 3ω method will be shown.

  3. Radiation Hardening of Silicon Detectors

    CERN Multimedia

    Leroy, C; Glaser, M

    2002-01-01

    %RD48 %title\\\\ \\\\Silicon detectors will be widely used in experiments at the CERN Large Hadron Collider where high radiation levels will cause significant bulk damage. In addition to increased leakage current and charge collection losses worsening the signal to noise, the induced radiation damage changes the effective doping concentration and represents the limiting factor to long term operation of silicon detectors. The objectives are to develop radiation hard silicon detectors that can operate beyond the limits of the present devices and that ensure guaranteed operation for the whole lifetime of the LHC experimental programme. Radiation induced defect modelling and experimental results show that the silicon radiation hardness depends on the atomic impurities present in the initial monocrystalline material.\\\\ \\\\ Float zone (FZ) silicon materials with addition of oxygen, carbon, nitrogen, germanium and tin were produced as well as epitaxial silicon materials with epilayers up to 200 $\\mu$m thickness. Their im...

  4. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Silane coupling reagent (3-mercaptopropyl trimethoxysilane (MPTS)) was used to prepare twodimensional self-assembled monolayer (SAM) on silicon substrate. The terminal –SH group was in situ oxidized to –SO3H group to endow the film with good chemisorption ability. Then TiO2 thin films were deposited on the ...

  5. Functionalization of titanium with chitosan via silanation: evaluation of biological and mechanical performances.

    Directory of Open Access Journals (Sweden)

    Pauline Renoud

    Full Text Available Complications in dentistry and orthopaedic surgery are mainly induced by peri-implant bacterial infections and current implant devices do not prevent such infections. The coating of antibacterial molecules such as chitosan on its surface would give the implant bioactive properties. The major challenge of this type of coating is the attachment of chitosan to a metal substrate. In this study, we propose to investigate the functionalization of titanium with chitosan via a silanation. Firstly, the surface chemistry and mechanical properties of such coating were evaluated. We also verified if the coated chitosan retained its biocompatibility with the peri-implant cells, as well as its antibacterial properties. FTIR and Tof-SIMS analyses confirmed the presence of chitosan on the titanium surface. This coating showed great scratch resistance and was strongly adhesive to the substrate. These mechanical properties were consistent with an implantology application. The Chitosan-coated surfaces showed strong inhibition of Actinomyces naeslundii growth; they nonetheless showed a non significant inhibition against Porphyromonas gingivalis after 32 hours in liquid media. The chitosan-coating also demonstrated good biocompatibility to NIH3T3 fibroblasts. Thus this method of covalent coating provides a biocompatible material with improved bioactive properties. These results proved that covalent coating of chitosan has significant potential in biomedical device implantation.

  6. Porous silicon gettering

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Menna, P.; Pitts, J.R. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    The authors have studied a novel extrinsic gettering method that uses the large surface areas produced by a porous-silicon etch as gettering sites. The annealing step of the gettering used a high-flux solar furnace. They found that a high density of photons during annealing enhanced the impurity diffusion to the gettering sites. The authors used metallurgical-grade Si (MG-Si) prepared by directional solidification casing as the starting material. They propose to use porous-silicon-gettered MG-Si as a low-cost epitaxial substrate for polycrystalline silicon thin-film growth.

  7. Influence of Etching Protocol and Silane Treatment with a Universal Adhesive on Lithium Disilicate Bond Strength.

    Science.gov (United States)

    Kalavacharla, V K; Lawson, N C; Ramp, L C; Burgess, J O

    2015-01-01

    To measure the effects of hydrofluoric acid (HF) etching and silane prior to the application of a universal adhesive on the bond strength between lithium disilicate and a resin. Sixty blocks of lithium disilicate (e.max CAD, Ivoclar Vivadent) were sectioned into coupons and polished. Specimens were divided into six groups (n=10) based on surface pretreatments, as follows: 1) no treatment (control); 2) 5% HF etch for 20 seconds (5HF); 3) 9.5% HF etch for 60 seconds (9.5HF); 4) silane with no HF (S); 5) 5% HF for 20 seconds + silane (5HFS); and 6) 9.5% HF for 60 seconds + silane (9.5HFS). All etching was followed by rinsing, and all silane was applied in one coat for 20 seconds and then dried. The universal adhesive (Scotchbond Universal, 3M ESPE) was applied onto the pretreated ceramic surface, air thinned, and light cured for 10 seconds. A 1.5-mm-diameter plastic tube filled with Z100 composite (3M ESPE) was applied over the bonded ceramic surface and light cured for 20 seconds on all four sides. The specimens were thermocycled for 10,000 cycles (5°C-50°C/15 s dwell time). Specimens were loaded until failure using a universal testing machine at a crosshead speed of 1 mm/min. The peak failure load was used to calculate the shear bond strength. Scanning electron microscopy images were taken of representative e.max specimens from each group. A two-way analysis of variance (ANOVA) determined that there were significant differences between HF etching, silane treatment, and the interaction between HF and silane treatment (puniversal adhesive.

  8. Silane coupling agent for attaching fusion-bonded epoxy to steel.

    Science.gov (United States)

    Tchoquessi Diodjo, Madeleine R; Belec, Lénaïk; Aragon, Emmanuel; Joliff, Yoann; Lanarde, Lise; Perrin, François-Xavier

    2013-07-24

    We describe the possibility of using γ-aminopropyltriethoxysilane (γ-APS) to increase the durability of epoxy powder coating/steel joints. The curing temperature of epoxy powder coatings is frequently above 200 °C, which is seen so far as a major limitation for the use of the heat-sensitive aminosilane coupling agent. Despite this limitation, we demonstrate that aminosilane is a competitive alternative to traditional chromate conversion to enhance the durability of epoxy powder coatings/steel joints. Fourier-transform reflection-absorption infrared spectroscopy (FT-RAIRS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) were used to identify the silane deposition conditions that influence the adhesion of epoxy powder coatings on steel. We show that AFM analysis provides highly sensitive measurements of mechanical property development and, as such, the degree of condensation of the silane. The joint durability in water at 60 °C was lower when the pH of the γ-APS solution was controlled at 4.6 using formic acid, rather than that at natural pH (10.6). At the curing temperature of 220 °C, oxidation of the carbon adjacent to the amine headgroup of γ-APS gives amide species by a pseudofirst-order kinetics. However, a few amino functionalities remain to react with oxirane groups of epoxy resin and, thus, strengthen the epoxy/silane interphase. The formation of ammonium formate in the acidic silane inhibits the reaction between silane and epoxy, which consequently decreases the epoxy/silane interphase cohesion. We find that the nanoroughness of silane deposits increases with the cure temperature which is beneficial to the wet stability of the epoxy/steel joints, due to increased mechanical interlocking.

  9. Hybrid Silicon-Based Organic/Inorganic Block Copolymers with Sol-Gel Active Moieties: Synthetic Advances, Self-Assembly and Applications in Biomedicine and Materials Science.

    Science.gov (United States)

    Czarnecki, Sebastian; Bertin, Annabelle

    2018-03-07

    Hybrid silicon-based organic/inorganic (multi)block copolymers are promising polymeric precursors to create robust nano-objects and nanomaterials due to their sol-gel active moieties via self-assembly in solution or in bulk. Such nano-objects and nanomaterials have great potential in biomedicine as nanocarriers or scaffolds for bone regeneration as well as in materials science as Pickering emulsifiers, photonic crystals or coatings/films with antibiofouling, antibacterial or water- and oil-repellent properties. Thus, this Review outlines recent synthetic efforts in the preparation of these hybrid inorganic/organic block copolymers, gives an overview of their self-assembled structures and finally presents recent examples of their use in the biomedical field and material science. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Silicon detectors

    International Nuclear Information System (INIS)

    Klanner, R.

    1984-08-01

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  11. Chemical modification of silicon surfaces for the application in soft lithography

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, S.

    2007-05-15

    The objective of this work was to chemically modify silicon surfaces by anchoring functional molecules. A major part was devoted to the investigation and improvement of the self-assembly process of organosilanes on oxidized silicon surfaces. The formation of a release agent layer with perfluorinated alkylsilanes was performed by vapor phase deposition. An advanced vapor phase deposition device, called CASINO device, was built to enhance the qualities of the thin films. It is possible to carry out cleaning and silanization in a closed chamber without exposing the samples to air in between. Thereby surface contamination is avoided. Experiments with the new device were performed following examples given in literature. To optimize the silanization process in the CASINO device, it was also planned to apply heat treatment of the sample during or after the deposition process. Surface layers of thiolterminated and of aminoterminated molecules were investigated as adhesive layer for the linkage of metal structures to silicon surfaces, e.g. Shuttle-Transfer Printing with gold crossbar electrodes. First, thiol- and aminoterminated organosilane SAMs were tested as adhesive layers for gold. The surface modified with thiolterminated silane molecules was further examined. Adhesion was promoted only after heat treatment of a thiolmodified silicon substrate with a gold layer on top. (orig.)

  12. Enhanced lithium battery with polyethylene oxide-based electrolyte containing silane-Al2 O3 ceramic filler.

    Science.gov (United States)

    Zewde, Berhanu W; Admassie, Shimelis; Zimmermann, Jutta; Isfort, Christian Schulze; Scrosati, Bruno; Hassoun, Jusef

    2013-08-01

    A solid polymer electrolyte prepared by using a solvent-free, scalable technique is reported. The membrane is formed by low-energy ball milling followed by hot-pressing of dry powdered polyethylene oxide polymer, LiCF3 SO3 salt, and silane-treated Al2 O3 (Al2 O3 -ST) ceramic filler. The effects of the ceramic fillers on the properties of the ionically conducting solid electrolyte membrane are characterized by using electrochemical impedance spectroscopy, XRD, differential scanning calorimeter, SEM, and galvanostatic cycling in lithium cells with a LiFePO4 cathode. We demonstrate that the membrane containing Al2 O3 -ST ceramic filler performs well in terms of ionic conductivity, thermal properties, and lithium transference number. Furthermore, we show that the lithium cells, which use the new electrolyte together with the LiFePO4 electrode, operate within 65 and 90 °C with high efficiency and long cycle life. Hence, the Al2 O3 -ST ceramic can be efficiently used as a ceramic filler to enhance the performance of solid polymer electrolytes in lithium batteries. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A thermochemical approach to enhance hydrophobicity of SiC/SiO{sub 2} powder using γ-methacryloxypropyl trimethoxy silane and octylphenol polyoxyethylene ether (7)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chunxue; Feng, Dandan; Wang, Xiangke; Li, Zhihong; Zhu, Yumei, E-mail: zhuyumei@tju.edu.cn

    2016-01-01

    Graphical abstract: Through the exploration of modification mechanism, the hydrophilic properties of SiC/SiO{sub 2}-KH570-OP-7 were far superior to SiC/SiO{sub 2}-KH570. - Highlights: • A novel universal method is performed to enhance hydrophobicity of SiC/SiO{sub 2} powder. • Through pyrolysis of KH570 and OP-7, hydrophilic groups is grafted. • The hydrophobicity of SiC/SiO{sub 2}-KH570-OP-7 was far superior to SiC/SiO{sub 2}-KH570. • A possible formation mechanism of hydrophilic surface was proposed. • Surface changes on SiC/SiO{sub 2}-KH570-OP-7 powder were analyzed via SEM, FTIR, XPS. - Abstract: A thermochemical synthetic methodology for silicon carbide/silica (SiC/SiO{sub 2}) powder modified by integrating γ-methacryloxypropyl trimethoxy silane (KH570) and octylphenol polyoxyethylene ether (7) (OP-7) with hydrophilic SiC/SiO{sub 2} particles is described. On account of weak hydrophobicity of SiC/SiO{sub 2} powder modified by KH570 (SiC/SiO{sub 2}-KH570), the study focuses on the improvement of hydrophobicity utilizing alkylation reaction between OP-7 and KH570 at high temperature. Compared with using KH570 alone, SiC/SiO{sub 2} powder modified by KH570 and OP-7 (SiC/SiO{sub 2}-KH570-OP-7) shows better water resistance, and also an increased contact angle from 73.8° to 136.4°, resulting thus an improved hydrophobicity. Fourier transform infrared spectroscopy (FTIR), as well as X-ray photoelectron spectroscopy (XPS), was utilized to characterize these surfaces, and the results indicated that KH570 and OP-7 can be covalently bonded on the surface of SiC/SiO{sub 2} powder. Furthermore, it has been deeply investigated in the paper not only the possible modes of non-oxidative thermal degradation of OP-7 and KH570, but also the formation mechanism of more hydrophobic SiC/SiO{sub 2}-KH570-OP-7 powder, which probably will have a potential utility for other inorganic materials.

  14. Emission spectroscopy on a supersonically expanding argon/silane plasma

    NARCIS (Netherlands)

    Meeusen, G.J.; Ershov-Pavlov, E.A.; Meulenbroeks, R.F.G.; Sanden, van de M.C.M.; Schram, D.C.

    1992-01-01

    Results from emission spectroscopy measurements on an Ar/SiH/sub 4/ plasma jet which is used for fast deposition of amorphous hydrogenated silicon are presented. The jet is produced by allowing a thermal cascaded arc plasma in argon (I=60 A, V=80 V, Ar flow=60 scc/s and pressure 4*10/sup 4/ Pa) to

  15. Electrospun a-Si using Liquid Silane/Polymer Inks

    Energy Technology Data Exchange (ETDEWEB)

    Doug Schulz

    2010-12-09

    Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.

  16. [Spectroscopic study on film formation mechanism and structure of composite silanes-V-Zr passive film].

    Science.gov (United States)

    Wang, Lei; Liu, Chang-sheng; Shi, Lei; An, Cheng-qiang

    2015-02-01

    A composite silanes-V-Zr passive film was overlayed on hot-dip galvanized steel. Attenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometer (XPS) and radio frequency glow discharge optical emission spectrometry (rf-GD-OES) were used to characterize the molecular structure of the silanes-V-Zr passive film. The mechanism of film formation was discussed: The results show that the silane molecules are crosslinked as the main film former and inorganic inhibitor is even distributed in the film. The fitting peak of 100.7 eV in XPS single Si2p energy range spectra of the composite silanes-V-Zr passive film and the widening and strengthening of the Si--O infrared absorption peak at 1100 cm(-1) indicate that the silanes were adsorbed on the surface of zinc with chemical bond of Si--O--Zn, and the silane molecules were connected with each other by bond of Si--O--Si. Two characteristic absorption peaks of amide at 1650 and 1560 cm(-1) appear in the infrared spectroscopy of the composite silanes-V-Zr passive film, and a characteristic absorption peak of epoxy groups at 910 cm(-1) disappears in the infrared spectroscopy of the passive film. The results indicate that gamma-APT can be prepared through nucleophilic ring-opening of ethylene oxide in gamma-GPT molecule to form C--N covalent bonds. The rf-GD-OES results indicate that there is a oxygen enriched layer in 0.3 microm depth of the composite silanes-V-Zr passive film. Moreover, ZrF4, ZrO2 and some inorganic matter obtained by the reaction during the forming processof the composite silanes-V-Zr passive film are distributed evenly throughout the film. According to the film composition, the physical processes and chemical reactions during the film forming process were studied by using ATR-FTIR. Based on this, the film forming mechanism was proposed.

  17. Understanding the interface between silicon-based materials and water: Molecular-dynamics exploration of infrared spectra

    Directory of Open Access Journals (Sweden)

    José A. Martinez-Gonzalez

    2017-11-01

    Full Text Available Molecular-dynamics simulations for silicon, hydrogen- and hydroxyl-terminated silicon in contact with liquid water, at 220 and 300 K, display water-density ‘ordering’ along the laboratory z-axis, emphasising the hydrophobicity of the different systems and the position of this first adsorbed layer. Density of states (DOS of the oxygen and proton velocity correlation functions (VACFs and infrared (IR spectra of the first monolayer of adsorbed water, calculated via Fourier transformation, indicate similarities to more confined, ice-like dynamical behaviour (redolent of ice. It was observed that good qualitative agreement is obtained between the DOS for this first layer in all systems. The DOS for the lower-frequency zone indicates that for the interface studied (i.e., the first layer near the surface, the water molecules try to organise in a similar form, and that this form is intermediate between liquid water and ice. For IR spectra, scrutiny of the position of the highest-intensity peaks for the stretching and bending bands indicate that such water molecules in the first solvating layer are organised in an intermediate fashion between ice and liquid water.

  18. Chemical modification of organoclay cloisite ®30B with silane 3-aminopropyltriethoxysilane

    International Nuclear Information System (INIS)

    Bertuoli, P.T.; Frizzo, V.P.; Zattera, A.J.; Scienza, L.C.

    2014-01-01

    The montmorillonite (MMT) is the inorganic phase more used in obtaining polymer nanocomposites. To improve the compatibility and dispersion of MMT in the polymer resin, many researchers have performed the process of functionalization of the clay with silane. This study was performed with the objective of modifying the Cloisite®30B clay with 3-aminopropyltriethoxysilane (APS). The modification was carried out by ion-exchange method using 10 g of clay Cloisite®30B (MMT-30B), 500 mL of hydroalcoholic solution (75/25 v/v) and 10 g of silane. The clay modified with silane (S-MMT_3_0_B) was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR). Through the XRD was observed an increase in the basal spacing d_0_0_1 of 1.82 to 2.2 nm. With the analysis of TGA was observed that S-MMT_3_0_B showed greater weight loss than MMT-30B due to decomposition of the silane. The presence of band at 1562 cm-1 in the FTIR spectrum of S-MMT_3_0_B confirmed the presence of silane in the structure of the modified clay. (author)

  19. Structural and Chemical Characterization of Silica Spheres before and after Modification by Silanization for Trypsin Immobilization

    Directory of Open Access Journals (Sweden)

    Eduardo F. Barbosa

    2017-01-01

    Full Text Available In the last decades, silica particles of a variety of sizes and shapes have been characterized and chemically modified for several applications, from chromatographic separation to dental supplies. The present study proposes the use of aminopropyl triethoxysilane (APTS silanized silica particles to immobilize the proteolytic enzyme trypsin for the development of a bioreactor. The major advantage of the process is that it enables the polypeptides hydrolysis interruption simply by removing the silica particles from the reaction bottle. Silanized silica surfaces showed significant morphological changes at micro- and nanoscale level. Chemical characterization showed changes in elemental composition, chemical environment, and thermal degradation. Their application as supports for trypsin immobilization showed high immobilization efficiency at reduced immobilization times, combined with more acidic conditions. Indirect immobilization quantification by reversed-phase ultrafast high performance liquid chromatography proved to be a suitable approach due to its high linearity and sensitivity. Immobilized trypsin activities on nonmodified and silanized silica showed promising features (e.g., selective hydrolysis for applications in proteins/peptides primary structure elucidation for proteomics. Silanized silica system produced some preferential targeting peptides, probably due to the hydrophobicity of the nanoenvironment conditioned by silanization.

  20. Effect of silane coupling agent on interfacial adhesion of copper/glass fabric/epoxy composites

    International Nuclear Information System (INIS)

    Langroudi, A. E.; Yousefi, A. A.; Kabiri, Kourosh

    2003-01-01

    The effect of silane coupling agent on the peel strength of copper/prep reg/copper composites was investigated. The composite consisted of one or two sheets of prepress covered by two copper plates. The prep reg was prepared by hand dry-lay-up technique using an epoxy resin and an electrical resistant glass fabric (e-glass style 2165). 4,4'-methylene dianiline. An aromatic amine, was used as curing agent. curing times for prep reg and composite at 120 d ig C and 170 d ig C were 15 min and 1 h, respectively. γ-aminopropyl trimethoxy silane was used as coupling agent. The effect of aminopropyl trimethoxy silane on the adhesion of epoxy/glass and epoxy/copper interfaces was investigated by two methods. In the first method, the surface of the glass fabric and/or the copper plates were treated by aminopropyl trimethoxy silane. In the second method, aminopropyl trimethoxy silane was directly added to epoxy resin. In addition, the effect of additional resin on the adhesion strength was also studied by the latter method