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Sample records for cz silicon final

  1. PV Cz silicon manufacturing technology improvements

    Science.gov (United States)

    Jester, T.

    1995-09-01

    This describes work done in the final phase of a 3-y, 3-phase contract to demonstrate cost reductions and improvements in manufacturing technology. The work focused on near-term projects in the SSI (Siemens Solar Industries) Czochralski (Cz) manufacturing facility in Camarillo, CA; the final phase was concentrated in areas of crystal growth, wafer technology, and environmental, safety, and health issues. During this period: (1) The crystal-growing operation improved with increased growth capacity; (2) Wafer processing with wire saws continued to progress; the wire saws yielded almost 50 percent more wafers per inch in production. The wire saws needs less etching, too; (3) Cell processing improvements focused on better handling and higher mechanical yield. The cell electrical distribution improved with a smaller standard deviation in the distribution; and (4) Module designs for lower material and labor costs continued, with focus on a new junction box, larger modules with larger cells, and less costly framing techniques. Two modules demonstrating these cost reductions were delivered during this phase.

  2. Degradation of bulk diffusion length in CZ silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reiss, J.H.; King, R.R.; Mitchell, K.W. [Siemens Solar Industries, Camarillo, CA (United States)

    1995-08-01

    Commercially-produced, unencapsulated, CZ silicon solar cells can lose 3 to 4% of their initial efficiency after exposure to light. After this initial, rapid ( < 30 min.) decrease, the cell power output remains stable. The cell performance recovers in a matter of hours in the dark at room temperature, and degrades again under light exposure. The different conditions under which CZ silicon cells degrade, and the reverse process, annealing, are characterized with the methods of spectral response and current-voltage (I-V) measurements. Iron impurities are a possible cause of this effect.

  3. Silicon nitride passivated bifacial Cz-silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, L. [Institute of Semiconductor Electronics, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen (Germany); Solland Solar Cells GmbH, Bohr 12, 52072 Aachen (Germany); Windgassen, H.; Baetzner, D.L. [Institute of Semiconductor Electronics, RWTH Aachen University, Sommerfeldstr. 24, 52074 Aachen (Germany); Bitnar, B.; Neuhaus, H. [Deutsche Cell GmbH, Berthelsdorfer Str. 111a, 09599 Freiberg (Germany)

    2009-08-15

    A new process for all silicon nitride passivated silicon solar cells with screen printed contacts is analysed in detail. Since the contacts are fired through the silicon nitride layers on both sides, the process is easy to adapt to industrial production. The potential and limits of the presented bifacial design are simulated and discussed. The effectiveness of the presented process depends strongly on the base doping of the substrate, but only the open circuit voltage is affected. The current is mainly determined by the rear surface passivation properties. Thus, using a low resistivity (<1.5{omega}cm) base material higher efficiencies compared to an aluminium back surface field can be achieved. (author)

  4. Infrared absorption peaks in nitrogen doped CZ silicon

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, N. [RIAST, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8570 (Japan); JEITA Nitrogen Measurement WG, 3-11 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan)]. E-mail: inouen@riast.osakafu-u.ac.jp; Nakatsu, M. [RIAST, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8570 (Japan); Ono, H. [Japan Fine Ceramics Center, 2-4-3 Nishi-shinbashi, Minato-ku, Tokyo 105-0003 (Japan); JEITA Nitrogen Measurement WG, 3-11 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Inoue, Y. [Tokyo University of Education, Bunkyo-ku, Tokyo 117-0002 (Japan)

    2006-10-15

    Dependences on annealing temperature and nitrogen concentration were examined for new local vibration mode infrared absorption peaks at 856, 973, 984 and 1002 cm{sup -1} in nitrogen-doped CZ silicon crystal. The new absorption peaks were so weak that two sets of samples were examined for temperature and concentration dependences, respectively, to get reliable results. The peak at 1002 cm{sup -1} behaved similarly for annealing, though much weaker, to the known peaks at 810 and 1018 cm{sup -1} which are attributed to interstitial N pair accompanied by the two oxygen interstitials (NNO {sub i}O {sub i}). This suggests that the origin contains 2 O {sub i} also. It was strong in low concentration regime, which is similar to the behavior of shallow thermal donors. This suggests that the structure contains one nitrogen rather than two (N-O interstitial pair). The results were compared with the electronic transition absorption by shallow thermal donors (STD). The absorptions at 1002 and 240 cm{sup -1} behaved similarly. These suggest that the peak at 1002 cm{sup -1} is likely due to NOO {sub i}O {sub i} which is the candidate for STD. The temperature dependence of the other new peaks was slightly different from each other. Origin of the other peaks is not clear yet.

  5. Minority carrier lifetime in furnace and E-beam annealed CZ silicon

    Energy Technology Data Exchange (ETDEWEB)

    Susi, E.; Lulli, G.; Passari, L.

    1987-05-01

    Thermally induced defects in CZ silicon are studied, with the aim of identifying the mechanisms responsible for lifetime changes and the role of oxygen in them. For low temperature heatings lifetime can either decrease or increase: a gettering activity of neutral oxygen clusters which participate in the dissociation equilibria of Fe-B pairs is postulated. The effects of pretreatments performed by a conventional diffusion furnace or by rapid thermal annealing are discussed.

  6. Plasma texturing on large-area industrial grade CZ silicon solar cells

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Nordseth, Ørnulf; Boisen, Anja

    2013-01-01

    -mono-crystalline Si. The process was successfully integrated in fabrication of solar cells using only industry standard processes on a Czochralski (CZ) silicon starting material. The resulting cell performance was compared to cells with conventional texturing. For cells, where the nanostructuring was not fully......We report on an experimental study of nanostructuring of silicon solar cells using reactive ion etching (RIE). A simple mask-less, scalable RIE nanostructuring of the solar cell surface is shown to reduce the AM1.5-weighted average reflectance to a level below 1 % in a fully optimized RIE texturing......, and thus holds a significant potential for improvement of the cell performance compared to current industrial standards. The reflectance is shown to remain below that of conventional textured cells also at high angle of incidence. The process is shown to be equally applicable to mono-, multi- and quasi...

  7. Local vibration modes of shallow thermal donors in nitrogen-doped CZ silicon crystals

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, N. [RIAST, Osaka Prefecture University, Sakai, 599-8570 (Japan) and Nitrogen Measurement WG, JEITA, Tokyo, 101-0062 (Japan)]. E-mail: inouen@riast.osakafu-u.ac.jp; Nakatsu, M. [RIAST, Osaka Prefecture University, Sakai, 599-8570 (Japan); Ono, H. [Japan Fine Ceramics Center, Tokyo, 105-0003 (Japan); Nitrogen Measurement WG, JEITA, Tokyo, 101-0062 (Japan)

    2006-04-01

    Local vibration mode (LVM) infrared absorption from shallow thermal donors (STD) composed of nitrogen-oxygen complexes in nitrogen-doped CZ silicon crystals was examined. The samples whose STD concentration had been determined were measured. The sample dependence of the peaks at 810 and 1018cm{sup -1} was similar to that of STD but the estimated concentration was slightly higher. New LVM peaks were found at 855, 973, 982, 1002cm{sup -1} and so on. Their magnitude and sample dependence agreed well with those of STD. Annealing temperature dependence of other samples supported the results. Annealing time dependence of STD concentration at 650 deg. C was examined. STD peaks at 250, 242 and those at 240, 234 and 238cm{sup -1} behaved differently, suggesting the presence of two kinds of STD origin.

  8. Utilization of Tabula Rasa to Stabilize Bulk Lifetimes in n-Cz Silicon for High-Performance Solar Cell Processing

    Energy Technology Data Exchange (ETDEWEB)

    LaSalvia, Vincenzo; Jensen, Mallory Ann; Youssef, Amanda; Nemeth, William; Page, Matthew; Buonassisi, Tonio; Stradins, Paul

    2016-11-21

    We investigate a high temperature, high cooling-rate anneal Tabula Rasa (TR) and report its implications on n-type Czochralski-grown silicon (n-Cz Si) for photovoltaic fabrication. Tabula Rasa aims at dissolving and homogenizing oxygen precipitate nuclei that can grow during the cell process steps and degrade the cell performance due to their high internal gettering and recombination activity. The Tabula Rasa thermal treatment is performed in a clean tube furnace with cooling rates >100 degrees C/s. We characterize the bulk lifetime by Sinton lifetime and photoluminescence mapping just after Tabula Rasa, and after the subsequent cell processing. After TR, the bulk lifetime surprisingly degrades to <; 0.1ms, only to recover to values equal or higher than the initial non-treated wafer (several ms), after typical high temperature cell process steps. Those include boron diffusion and oxidation; phosphorus diffusion/oxidation; ambient annealing at 850 degrees C; and crystallization annealing of tunneling-passivating contacts (doped polycrystalline silicon on 1.5 nm thermal oxide). The drastic lifetime improvement during high temperature cell processing is attributed to improved external gettering of metal impurities and annealing of intrinsic point defects. Time and injection dependent lifetime spectroscopy further reveals the mechanisms of lifetime improvement after Tabula Rasa treatment. Additionally, we report the efficacy of Tabula Rasa on n-type Cz-Si wafers and its dependence on oxygen concentration, correlated to position within the ingot.

  9. Temperature-dependent Hall effect measurements on Cz-grown silicon pulled from compensated and recycled feedstock materials

    Science.gov (United States)

    Zhang, Song; Modanese, Chiara; Di Sabatino, Marisa; Tranell, Gabriella

    2015-11-01

    In this work, temperature-dependent Hall effect measurements in the temperature range 88-350 K were carried out to investigate the electrical properties of three solar grade p-type Czochralski (Cz) silicon ingots, pulled from recycled p-type multi-crystalline silicon top cuts and compensated solar grade (SoG) feedstock. Material bulk properties including Hall mobility, carrier density and resistivity as functions of temperature were studied to evaluate the influence of compensation and impurities. Recycled top cut replacing poly-silicon as feedstock leads to a more uniform resistivity. In addition, higher concentrations of O and C, give rise to oxygen related defects, which act as neutral scattering centers displaying only a slight influence on the electrical properties at low temperature compared to the dominant compensation effect. The electrical performances of all samples are shown to be strongly dependent on compensation level, especially at the lowest temperature (~88 K). A significant presence of incompletely ionized phosphorus was deduced through the measured carrier density. The temperature-dependent Hall effect measurements fit Klaassen's mobility model very well at low temperatures (doped silicon, while the deviation at the high temperature probably may be accounted for by the presence of as-grown defects, such as oxygen related defects and phosphorus clusters, which are usually neglected in most mobility models.

  10. MCZ: Striations in CZ silicon crystals grown under various axial magnetic field strengths

    Science.gov (United States)

    Kim, G. K. M.

    1985-01-01

    Suppression of fluid flow instabilities in the melt by the axial magnetic field in Czochralski silicon crystal growth (AMCZ) is investigated precisely by a high-sensitivity striation etching in conjunction with temperature measurements. The magnetic strength (B) was varied up to 4.0 kG, incremented in 0.5 kG/5 cm crystal length. The convection flow was substantially suppressed at B 1.0 kG. A low oxygen level of 2-3 ppma and a high resistivity of 400 ohm-cm is achieved in the AMCZ silicon crystals at B 1.0 kG. Details of the striation formation as a function of B are presented. Computer simulation of the magnetohydrodynamics of the AMCZ silicon crystal growth are discussed briefly with regard to the solute, especially oxygen segregation at B=0, 1.0, and 2.0 kG. Earlier studies in the inverted Bridgman growth of InSb and Ge, which have established the cause and effect relationship between the convection in the melt and the striation formation as well as the suppression of the convections in the melt by transverse magnetic field are reviewed.

  11. Crystal shape 2D modeling for transient CZ silicon crystal growth

    Science.gov (United States)

    Sabanskis, A.; Bergfelds, K.; Muiznieks, A.; Schröck, Th.; Krauze, A.

    2013-08-01

    A non-stationary axisymmetric model of Czochralski silicon single crystal growth is presented. The model describes transient behavior of crystal-melt, melt-gas and crystal-gas interfaces in connection with PID-based control of crystal diameter by changing crystal pulling velocity and heater power. To calculate significant crystal shape changes, unstructured finite element mesh is used in crystal and melt together with automatic element size control. Heater temperature changes are modeled with a simplified integral model. A numerical simulation example of start cone growth is given.

  12. Thermal history effect on the nucleation of oxygen precipitates in germanium doped Cz-silicon studied by high-energy X-ray diffraction

    Science.gov (United States)

    Li, Zhen; Will, Johannes; Dong, Peng; Yang, Deren

    2017-12-01

    The oxygen (O) precipitate growth kinetics from moderate and high germanium (Ge) doped Czochralski-growth silicon (Cz-Si) are in-situ investigated at 1000 °C utilizing high-energy X-ray diffraction and analyzed with respect to precipitate density within a diffusion-driven growth model. Distinct different precipitation kinetics are observed for high Ge doped specimens. From the comparison of three thermal treatments, it was found that even for a high Ge concentration the nucleation rate at 800 °C is not influenced, however it facilitates larger grown-in precipitates of smaller amount as compared to the precipitates in undoped and moderately Ge doped samples. However, those grown-in O precipitates can be erased either by a direct annealing at 1200 °C or 1000 °C , but on the other hand stabilized by an annealing step at 800 °C, which in this manner as a drift step of grown-in precipitates for the high Ge-doped samples. In comparison additional nuclei are formed at 800 °C in the moderate and undoped cases.

  13. Numerical simulation of thermal history for Czochralski growth of silicon single crytals. CZ ho ni yoru silicon tankessho seicho katei no netsurireki kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Fujioka, K.; Sugino, Y. (Hitachi, Ltd., Tokyo (Japan)); Nakayama, W. (Tokyo Institute of Tecnology, Tokyo (Japan). Faculty of Engineering)

    1992-10-25

    In order to reveal the effect of thermal parameters on the thermal history of crystals in Czochralski growth of silicon single crystals, the numerical simulation was conducted under conditions of 16-26 cm in crystal diameter and 0.1-0.5 in emissivity on a crucible inner wall. As a result, radiation from the crucible inner wall and melt free surface had great effect on crystal growth. The pull speed of crystals decreased and the concavity of a solid-melt interface into crystals increased with an increase in crystal diameter. As the emissivity on the crucible inner wall was reduced from 0.5 to 0.3, the pull speed of the crystal of 21 cm in diameter was equivalent to that of 16 cm. In addition, the analytical result well agreed with the pull speeds measured on production equipment, and the shape of the crystal-melt interface showed a tendency to qualitatively agree with observations by X-ray diffraction. 11 refs., 15 figs., 3 tabs.

  14. 78 FR 29322 - Silicon Metal From the People's Republic of China: Final Results and Final No Shipments...

    Science.gov (United States)

    2013-05-20

    ... International Trade Administration Silicon Metal From the People's Republic of China: Final Results and Final No... the antidumping duty order on silicon metal from the People's Republic of China (``PRC'').\\1\\ The...\\ See Silicon Metal From the People's Republic of China: Preliminary Results of Antidumping Duty...

  15. Silicon solar cells with high efficiencies. Final report; Silicium-Solarzellen mit hoechsten Wirkungsgraden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Wettling, W.; Knobloch, J.; Glunz, S.W.; Henninger, V.; Kamerewerd, F.J.; Koester, B.; Leimenstoll, A.; Schaeffer, E.; Schumacher, J.; Sterk, S.; Warta, W.

    1996-06-01

    In this report the basic activities for the development of the silicon high efficiency solar cell technology are described. The project had two main goals: (i) The improvement of efficiencies using a systematic optimization of all cell parameters and technology steps and (ii) the simplification of the technology towards the possibilities of an industrial production, keeping the cell efficiency at a high level. Starting from the LBSF technology, developed at Fraunhofer ISE, the reduction of all loss mechanisms led to efficiencies up to 22.5% on FZ-silicon. Using a modification of this technology efficiencies of up to 21.7% have been reached on Cz-silicon. Even after the reduction of the number of photolithographic steps from six to three efficiencies up to 21.6% on FZ- and 19.5% on Cz-silicon have been obtained. These are best values in an international comparison. (orig.) [Deutsch] In diesem Projektbericht werden grundlegende Arbeiten zur Entwicklung der Silicium-`Highefficiency`-Solarzellentechnologie beschrieben. Das Projekt hatte zwei Hauptziele: (i) Die Erhoehung der Wirkungsgrade durch eine systematische Optimierung aller Zellparameter und aller Technologieschritte und (ii) die Vereinfachung der Technologie unter Beibehaltung sehr hoher Wirkungsgrade mit dem Ziel einer Annaeherung an die Moeglichkeiten der Industriefertigung. Ausgehend von der im Fraunhofer ISE entwickelten LBSF-Technologie gelang es durch Reduzierung aller Verlustmechanismen, Wirkungsgrade bis zu 22.5% auf FZ-Silicium zu erreichen. Nach Anpassung der Technologie wurden auf Cz-Silicium Wirkungsgrade bis 21.7% erzielt. Ein von sechs auf drei Fotomaskenschritte reduzierter Prozess erzielte immerhin noch Werte bis 21.6% auf FZ- und 19.5% auf Cz-Material. Alle dieser Werte stellen im internationalen Vergleich Spitzenleistungen dar. (orig.)

  16. 77 FR 54563 - Silicon Metal from the People's Republic of China: Final Results of Antidumping Duty...

    Science.gov (United States)

    2012-09-05

    ...] Silicon Metal from the People's Republic of China: Final Results of Antidumping Duty Administrative Review... administrative review of the antidumping duty order on silicon metal from the People's Republic of China (``PRC..., respectively. SUPPLEMENTARY INFORMATION: On March 7, 2012, the Department published Silicon Metal from the...

  17. Processing development for ceramic structural components: the influence of a presintering of silicon on the final properties of reaction bonded silicon nitride. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1982-03-01

    The influence of a presintering of silicon on the final properties of reaction bonded silicon nitride has been studied using scanning electron and optical microscopy, x-ray diffraction analysis, 4 pt. bend test, and mecury intrusion porosimetry. It has been shown that presintering at 1050/sup 0/C will not affect the final nitrided properties. At 1200/sup 0/C, the oxide layer is removed, promoting the formation of B-phase silicon nitride. Presintering at 1200/sup 0/C also results in compact weight loss due to the volatilization of silicon, and the formation of large pores which severely reduce nitrided strength. The development of the structure of sintered silicon compacts appears to involve a temperature gradient, with greater sintering observed near the surface.

  18. 76 FR 7811 - Silicon Metal From the People's Republic of China: Amended Final Results of Antidumping Duty...

    Science.gov (United States)

    2011-02-11

    ... International Trade Administration Silicon Metal From the People's Republic of China: Amended Final Results of... the final results of the antidumping duty administrative review of silicon metal from the People's Republic of China (``PRC''). See Silicon Metal From the People's Republic of China: Final Results and...

  19. Low Cost Solar Array Project cell and module formation research area. Process research of non-CZ silicon material. Final report, November 26, 1980-September 30, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R.B.

    1983-01-01

    The primary objective of the work reported was to investigate high-risk, high-payoff research areas associated with the Westinghouse process for producing photovoltaic modules using non-Czochralski sheet material. These tasks were addressed: technical feasibility study of forming front and back junctions using liquid dopant techniques, liquid diffusion mask feasibility study, application studies of antireflective material using a meniscus coater, ion implantation compatibility/feasibility study, and cost analysis. (LEW)

  20. Silicon halide-alkali metal flames as a source of solar grade silicon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Olson, D.B.; Miller, W.J.; Gould, R.K.

    1980-01-01

    The object of this program was to determine the feasibility of using continuous high-temperature reactions of alkali metals and silicon halides to produce silicon in large quantities and of suitable purity for use in the production of photovoltaic solar cells. Equilibrium calculations showed that a range of conditions were available where silicon was produced as a condensed phase but the byproduct alkali metal salt was a vapor. A process was proposed using the vapor phase reaction of Na with SiCl/sub 4/. Low pressure experiments were performed demonstrating that free silicon was produced and providing experience with the construction of reactant vapor generators. Further experiments at higher reagent flow rates were performed in a low temperature flow tube configuration with co-axial injection of reagents. Relatively pure silicon was produced in these experiments. A high temperature graphite flow tube was built and continuous separation of Si from NaCl was demonstrated. A larger-scaled well-stirred reactor was built. Experiments were performed to investigate the compatibility of graphite-based reactor materials of construction with sodium. At 1100 to 1200 K none of these materials were found to be suitable. At 1700 K the graphites performed well with little damage except to coatings of pyrolytic graphite and silicon carbide which were damaged.

  1. 77 FR 10477 - Silicon Metal From the People's Republic of China: Final Results of the Expedited Third Sunset...

    Science.gov (United States)

    2012-02-22

    ... International Trade Administration Silicon Metal From the People's Republic of China: Final Results of the... (``the Department'') initiated the third sunset review of the antidumping duty order on silicon metal..., the Department conducted an expedited (120-day) sunset review of the antidumping duty order on silicon...

  2. 75 FR 15412 - Silicon Metal From the People's Republic of China: Notice of Amended Final Results of New Shipper...

    Science.gov (United States)

    2010-03-29

    ... International Trade Administration Silicon Metal From the People's Republic of China: Notice of Amended Final... (``the Department'') determination of the appropriate surrogate value for silica fume in Silicon Metal... Order at 14. \\1\\ Respondents referenced here are (1) Jiangxi Gangyuan Silicon Industry Co., Ltd...

  3. 78 FR 61334 - Silicon Metal From the Russian Federation: Final Results of the Expedited Second Sunset Review of...

    Science.gov (United States)

    2013-10-03

    ... International Trade Administration Silicon Metal From the Russian Federation: Final Results of the Expedited... silicon metal from the Russian Federation.\\1\\ The Department finds that revocation of this antidumping...-0197. SUPPLEMENTARY INFORMATION: Background The antidumping duty order on silicon metal from the...

  4. 75 FR 1592 - Silicon Metal from the People's Republic of China: Final Results and Partial Rescission of...

    Science.gov (United States)

    2010-01-12

    ... International Trade Administration A-570-806 Silicon Metal from the People's Republic of China: Final Results... administrative review of the antidumping duty order on silicon metal from the People's Republic of China (``PRC... value during the period of review (``POR''), June 1, 2007, through May 31, 2008. \\1\\ See Silicon Metal...

  5. 75 FR 20812 - Silicon Metal from Brazil: Amended Final Results of Administrative Review Pursuant to Court Decision

    Science.gov (United States)

    2010-04-21

    ... International Trade Administration Silicon Metal from Brazil: Amended Final Results of Administrative Review... Commerce (``the Department'') regarding the administrative review of the antidumping duty order on Silicon Metal from Brazil for the period of review beginning July 1, 1996, through June 30, 1997. See Silicon...

  6. 77 FR 35425 - Crystalline Silicon Photovoltaic Cells and Modules From China; Scheduling of the Final Phase of...

    Science.gov (United States)

    2012-06-13

    ... amorphous silicon (a-Si), cadmium telluride (CdTe), or copper indium gallium selenide (CIGS). Also excluded... COMMISSION Crystalline Silicon Photovoltaic Cells and Modules From China; Scheduling of the Final Phase of... crystalline silicon photovoltaic cells and modules, provided for in subheadings 8501.31.80, 8501.61.00, 8507...

  7. High temperature Hexoloy{trademark} SX silicon carbide. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, G.V.; Lau, S.K.; Storm, R.S. [Carborundum Co., Niagara Falls, NY (United States)

    1994-09-01

    HEXOLOY{reg_sign} SX-SiC, fabricated with Y and Al containing compounds as sintering aids, has been shown to possess significantly improved strength and toughness over HEXOLOY{reg_sign}SA-SiC. This study was undertaken to establish and benchmark the complete mechanical property database of a first generation material, followed by a process optimization task to further improve the properties. Mechanical characterization on the first generation material indicated that silicon-rich pools, presumably formed as a reaction product during sintering, controlled the strength from room temperature to 1,232 C. At 1,370 C in air, the material was failing due to a glass-phase formation at the surface. This glass-phase formation was attributed to the reaction of yttrium aluminates, which exist as a second phase in the material, with the ambient. This process was determined to be a time-dependent one that leads to slow crack growth. Fatigue experiments clearly indicated that the slow crack growth driven by the reaction occurred only at temperatures >1,300 C, above the melting point of the glass phase. Process optimization tasks conducted included the selection of the best SiC powder source, studies on mixing/milling conditions for SiC powder with the sintering aids, and a designed experiment involving a range of sintering and post-treatment conditions. The optimization study conducted on the densification variables indicated that lower sintering temperatures and higher post-treatment pressures reduce the Si-rich pool formation, thereby improving the room-temperature strength. In addition, it was also determined that furnacing configuration and atmosphere were critical in controlling the Si-rich formation.

  8. Analytical and experimental evaluation of joining silicon carbide to silicon carbide and silicon nitride to silicon nitride for advanced heat engine applications Phase 2. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, G.J.; Vartabedian, A.M.; Wade, J.A.; White, C.S. [Norton Co., Northboro, MA (United States). Advanced Ceramics Div.

    1994-10-01

    The purpose of joining, Phase 2 was to develop joining technologies for HIP`ed Si{sub 3}N{sub 4} with 4wt% Y{sub 2}O{sub 3} (NCX-5101) and for a siliconized SiC (NT230) for various geometries including: butt joins, curved joins and shaft to disk joins. In addition, more extensive mechanical characterization of silicon nitride joins to enhance the predictive capabilities of the analytical/numerical models for structural components in advanced heat engines was provided. Mechanical evaluation were performed by: flexure strength at 22 C and 1,370 C, stress rupture at 1,370 C, high temperature creep, 22 C tensile testing and spin tests. While the silicon nitride joins were produced with sufficient integrity for many applications, the lower join strength would limit its use in the more severe structural applications. Thus, the silicon carbide join quality was deemed unsatisfactory to advance to more complex, curved geometries. The silicon carbide joining methods covered within this contract, although not entirely successful, have emphasized the need to focus future efforts upon ways to obtain a homogeneous, well sintered parent/join interface prior to siliconization. In conclusion, the improved definition of the silicon carbide joining problem obtained by efforts during this contract have provided avenues for future work that could successfully obtain heat engine quality joins.

  9. Final Size Planar Edgeless Silicon Detectors for the TOTEM Experiment

    CERN Document Server

    Noschis, E; Anelli, G; Avati, V; Berardi, V; Boccone, V; Bozzo, M; Brucken, E; Buzzo, A; Catanesi, M G; Cereseto, R; Cuneo, S; Da Vià, C; Deile, M; Dinapoli, R; Eggert, K; Egorov, N; Eremin, I; Ferro, F; Hasi, J; Haug, F; Heino, J; Jarron, P; Kalliopuska, J; Kaspar, J; Kok, A; Kozlov, Y; Kundrat, W; Kurvinen, K; Lauhakangas, R; Lokajícek, M; Luntama, T; Macina, D; Macri, M; Minutoli, S; Mirabito, L; Morelli, A; Musico, P; Negri, M; Niewiadomski, H; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Perrot, A L; Puppo, R; Radermacher, E; Radicioni, E; Saarikko, H; Santroni, A; Sette, G; Sidorov, A; Siegrist, P; Smotlacha, J; Snoeys, W; Taylor, C; Watts, S; Whitmoree, J

    2006-01-01

    The TOTEM experiment will detect leading protons scattered in angles of microradians from the interaction point at the Large Hadron Collider. This will be achieved using detectors with a minimized dead area at the edge. The collaboration has developed an innovative structure at the detector edge reducing the conventional dead width to less than 100 microns, still using standard planar fabrication technology. In this new development, the current of the surface is decoupled from the sensitive volume current within a few tens of micrometers. The basic working principle is explained in this paper. Final size detectors have been produced using this approach. The current-voltage and current-temperature characteristics of the detectors were studied and the detectors were successfully tested in a coasting beam experiment.

  10. Final size planar edgeless silicon detectors for the TOTEM experiment

    Science.gov (United States)

    Noschis, E.; Alagoz, E.; Anelli, G.; Avati, V.; Berardi, V.; Boccone, V.; Bozzo, M.; Brucken, E.; Buzzo, A.; Catanesi, M. G.; Cereseto, R.; Cuneo, S.; Da Viá, C.; Deile, M.; Dinapoli, R.; Eggert, K.; Egorov, N.; Eremin, I.; Ferro, F.; Hasi, J.; Haug, F.; Heino, J.; Jarron, P.; Kalliopuska, J.; Kašpar, J.; Kok, A.; Kozlov, Y.; Kundrát, W.; Kurvinen, K.; Lauhakangas, R.; Lokajíček, M.; Luntama, T.; Macina, D.; Macrí, M.; Minutoli, S.; Mirabito, L.; Morelli, A.; Musico, P.; Negri, M.; Niewiadomski, H.; Oljemark, F.; Orava, R.; Oriunno, M.; Österberg, K.; Perrot, A.-L.; Puppo, R.; Radermacher, E.; Radicioni, E.; Saarikko, H.; Santroni, A.; Sette, G.; Sidorov, A.; Siegrist, P.; Smotlacha, J.; Snoeys, W.; Taylor, C.; Watts, S.; Whitmore, J.

    2006-07-01

    The TOTEM experiment will detect leading protons scattered in angles of microradians from the interaction point at the large hadron collider. This will be achieved using detectors with a minimized dead area at the edge. The collaboration has developed an innovative structure at the detector edge reducing the conventional dead width to less than 100 μm, still using standard planar fabrication technology. In this new development, the current of the surface is decoupled from the sensitive volume current within a few tens of micrometers. The basic working principle is explained in this paper. Final size detectors have been produced using this approach. The current-voltage and current-temperature characteristics of the detectors were studied and the detectors were successfully tested in a coasting beam experiment.

  11. Evaluation and silicon nitride internal combustion engine components. Final report, Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Voldrich, W. [Allied-Signal Aerospace Co., Torrance, CA (United States). Garrett Ceramic Components Div.

    1992-04-01

    The feasibility of silicon nitride (Si{sub 3}N{sub 4}) use in internal combustion engines was studied by testing three different components for wear resistance and lower reciprocating mass. The information obtained from these preliminary spin rig and engine tests indicates several design changes are necessary to survive high-stress engine applications. The three silicon nitride components tested were valve spring retainers, tappet rollers, and fuel pump push rod ends. Garrett Ceramic Components` gas-pressure sinterable Si{sub 3}N{sub 4} (GS-44) was used to fabricate the above components. Components were final machined from densified blanks that had been green formed by isostatic pressing of GS-44 granules. Spin rig testing of the valve spring retainers indicated that these Si{sub 3}N{sub 4} components could survive at high RPM levels (9,500) when teamed with silicon nitride valves and lower spring tension than standard titanium components. Silicon nitride tappet rollers showed no wear on roller O.D. or I.D. surfaces, steel axles and lifters; however, due to the uncrowned design of these particular rollers the cam lobes indicated wear after spin rig testing. Fuel pump push rod ends were successful at reducing wear on the cam lobe and rod end when tested on spin rigs and in real-world race applications.

  12. Thin film silicon solar cells: advanced processing and characterization - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ballif, Ch.

    2008-04-15

    This final report elaborated for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a project carried out at the photovoltaics laboratory at the University of Neuchatel in Switzerland. The project aimed to demonstrate the production of high-efficiency thin-film silicon devices on flexible substrates using low cost processes. New ways of improving processing and characterisation are examined. The process and manufacturing know-how necessary to provide support for industrial partners within the framework of further projects is discussed. The authors state that the efficiency of most devices was significantly improved, both on glass substrates and on flexible plastic foils. The process reproducibility was also improved and the interactions between the different layers in the device are now said to be better understood. The report presents the results obtained and discusses substrate materials, transparent conductors, defect analyses and new characterisation tools. Finally, the laboratory infrastructure is described.

  13. DML-CZ v systému DSpace

    OpenAIRE

    Krejčíř Vlastimil

    2008-01-01

    Prezentace se věnuje popisu projektu České digitální matematické knihovny (DML-CZ) a její implementaci v open-source systému DSpace. Shrnuje základní funkce a navržený datový model DML-CZ pro systém DSpace. Presentation is on building Czech digital library (DML-CZ) in open-source system DSpace. It sums up general functions and shows designed data model of DML-CZ in DSpace system.

  14. Thermal aging effect in oxi-reduction properties and catalytic activity of CZ and Pd-CZ catalyst; O efeito da desativacao termica nas propriedades oxirredutoras e na atividade catalitica de catalisadores CZ e Pd-CZ

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Daniela Cruz Damasceno da; Zotin, Fatima Maria Zanon, E-mail: fmzzotin@gmail.com [Departamento de Operacoes e Projetos Industriais, Instituto de Quimica, Universidade do Estado do Rio de Janeiro, RJ (Brazil); Neumann, Reiner [Coordenacao de Analises Minerais, Centro de Tecnologia Mineral, Rio de Janeiro, RJ (Brazil); Hori, Carla Eponina [Faculdade de Engenharia Quimica, Universidade Federal de Uberlandia, MG (Brazil); Cardoso, Mauri Jose Baldini [Centro de Pesquisas e Desenvolvimento Leopoldo Americo Miguez de Melo - PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Automotive catalyst, using in Brazil since 1992, is a essential technology for vehicular emissions control. Noble metals are the active phase of these catalysts, and cerium zirconium mixed oxides (CZ), responsible for the oxygen storage capacity (OSC), one of the most important aspect for the operational performance of the catalyst. In this context, the oxireduction properties analysis of CZ and Pd/CZ (palladium supported in CZ) system are the objective of this study, as well as, the impact of the thermal aging in the OSC. Aging consisted of treatments at 900 or 1200 degree C, for 12 or 36 h, in oxidizing condition. (author)

  15. Revitalize the US silicon/ferrosilicon industry through energy-efficient technology. Part 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Larson, H.R.; Welborn, J.H.

    1995-02-01

    It is concluded that silicon metal and ferrosilicon can be very effectively produced in a DC submerged arc furnace. Specific energy consumption factors measured were favorable to the technology. Significant energy savings over conventional AC practice are likely. Hollow electrode feeding of the furnace does not appear feasible. Electrode consumption was 0.144 lbs/lb so silicon while making metal, much of which occurred above the burden pile. Silicon loss to fume averaged 19.5% of the silicon charge. In this furnace, 50% FeSi was more difficult to produce than silicon metal, and the furnace could not be run with full burden; it was operated successfully about 3/4 full. In the silicon metal portion, the furnace was operated in a fully submerged mode for several 3-day test campaigns. The industry must seriously consider the identified benefits of DC plasma arc technology for retrofit or new added silicon capacity.

  16. Quantitative analysis of defects in silicon. Silicon sheet growth development for the Large Area Silicon Sheet Task of the Low-Cost Solar Array Project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Natesh, R.; Smith, J.M.; Bruce, T.; Qidwai, H.A.

    1980-04-01

    The complete procedures for the defect analysis of silicon samples using a QTM-720 Image Analyzing System are described, chemical polishing, etching, and QTM operation are discussed. The data from one hundred and seventy four (174) samples, and a discussion of the data are included. The data include twin boundary density, dislocation pit density, and grain boundary length. (WHK)

  17. Final report on LDRD Project: Quantum confinement and light emission in silicon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Guilinger, T.R.; Kelly, M.J.; Follstaedt, D.M. [and others

    1995-02-01

    Electrochemically formed porous silicon (PS) was reported in 1991 to exhibit visible photoluminescence. This discovery could lead to the use of integrated silicon-based optoelectronic devices. This LDRD addressed two general goals for optical emission from Si: (1) investigate the mechanisms responsible for light emission, and (2) tailor the microstructure and composition of the Si to obtain photoemission suitable for working devices. PS formation, composition, morphology, and microstructure have been under investigation at Sandia for the past ten years for applications in silicon-on-insulator microelectronics, micromachining, and chemical sensors. The authors used this expertise to form luminescent PS at a variety of wavelengths and have used analytical techniques such as in situ Raman and X-ray reflectivity to investigate the luminescence mechanism and quantify the properties of the porous silicon layer. Further, their experience with ion implantation in Si lead to an investigation into alternate methods of producing Si nanostructures that visibly luminesce.

  18. Large-area Silicon-Film{trademark} panels and solar cells. Final technical report, July 1995--March 1998

    Energy Technology Data Exchange (ETDEWEB)

    Rand, J.A.; Bai, Y.; Barnett, A.M.; Culik, J.S.; Ford, D.H.; Hall, R.B.; Kendall, C.L. [AstroPower, Inc., Newark, DE (US)

    1998-09-01

    This report will detail substantial improvements in each of the task areas. A number of new products were developed, including a 130 kW array built using a new panel design. Improvements in laboratory-scale solar cell processing resulted in a confirmed efficiency of 16.6%. A new Silicon-Film{trademark} production sheet machine was built which increased throughput by 70%. Three solar cell fabrication processes were converted from low throughout batch processes to high throughput, continuous, belt processes. These new processes are capable of processing sheet over 31 cm in width. Finally, a new Silicon-Film{trademark} sheet machine was built that demonstrated a sheet width of 38 cm. This tool enabled AstroPower to demonstrate a wide range of solar cell sizes, many of which have generated considerable market interest.

  19. Rf-plasma synthesis of nanosize silicon carbide and nitride. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Buss, R.J.

    1997-02-01

    A pulsed rf plasma technique is capable of generating ceramic particles of 10 manometer dimension. Experiments using silane/ammonia and trimethylchlorosilane/hydrogen gas mixtures show that both silicon nitride and silicon carbide powders can be synthesized with control of the average particle diameter from 7 to 200 nm. Large size dispersion and much agglomeration appear characteristic of the method, in contrast to results reported by another research group. The as produced powders have a high hydrogen content and are air and moisture sensitive. Post-plasma treatment in a controlled atmosphere at elevated temperature (800{degrees}C) eliminates the hydrogen and stabilizes the powder with respect to oxidation or hydrolysis.

  20. Determination of a definition of solar grade silicon. Final report, October 1975--September 1976

    Energy Technology Data Exchange (ETDEWEB)

    Christ, M.H.; Gupta, K.P.; Gutsche, H.W.; Hill, D.E.; Tucker, W.F.; Wang, M.S.

    1976-01-01

    The results are given of work on the effects of the impurities Al, C, Cr, Cu, Fe, Mg, Mn, Na, Ni, O, Ti, V, and Zr on the performance of silicon solar cells. A series of experimental silicon crystals were prepared containing controlled amounts of these impurities in otherwise semiconductor-grade silicon single crystals. Using these crystals, solar cells were prepared and the solar energy conversion efficiencies of these devices were measured against a standard cell. As expected, cell efficiency was found to be degraded in various degrees by most of the impurities under investigation. Surprisingly, degradation of efficiency was most severe in the presence of titanium and vanadium. For a greater than or equal to 10% device the concentration of Ti must be kept below approximately 6 x 10/sup 13/ atoms/cm/sup 3/ and that of V below approximately 1.2 10/sup 14/ atoms/cm/sup 3/. On the other hand, silicon solar cell material may contain as much as 10/sup 17/ atoms/cm/sup 3/ of aluminum or carbon, 10/sup 16/ atoms/cm/sup 3/ of nickel, but only about 10/sup 15/ atoms/cm/sup 3/ of manganese, chromium, iron, copper, zirconium, and magnesium to yield a solar device of acceptable performance.

  1. Patterning of hydrogenated microcrystalline silicon growth by magnetic field

    Czech Academy of Sciences Publication Activity Database

    Fejfar, Antonín; Stuchlík, Jiří; Mates, Tomáš; Ledinský, Martin; Honda, Shinya; Kočka, Jan

    2005-01-01

    Roč. 87, č. 1 (2005), 011901/1-011901/3 ISSN 0003-6951 R&D Projects: GA AV ČR(CZ) IAA1010316; GA AV ČR(CZ) IAA1010413; GA ČR(CZ) GD202/05/H003 Institutional research plan: CEZ:AV0Z10100521 Keywords : hydrogenated microcrystalline silicon * magnet ic field growth Subject RIV: BM - Solid Matter Physics ; Magnet ism Impact factor: 4.127, year: 2005

  2. Light-trapped, interconnected, Silicon-Film{trademark} modules. Final technical status report

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B.; Rand, J.A.; Ford, D.H.; Ingram, A.E. [AstroPower, Inc., Newark, DE (United States)

    1998-04-01

    AstroPower has continued its development of an advanced thin-silicon-based photovoltaic module product. This module combines the performance advantages of thin light-trapped silicon layers with the capability of integration into a low-cost, monolithically interconnected module. This report summarized work carried out over a 3-year, cost-shared contract. Key results accomplished during this phase include an NREL-verified conversion efficiency of 12.5% on a 0.47-cm{sup 2} device. The device structure used an insulating substrate and an active layer less than 100 {micro}m thick. A new metalization scheme was designed using insulating crossovers. This technology was demonstrated on a 36-segment, 321-cm{sup 2}, interconnected module. That module was tested at NREL with an efficiency of 9.79%. Further advances in metalization have led to an advanced single back-contact design that will offer low cost through ease of processing and higher performance through reduced shading.

  3. Development of a model and computer code to describe solar grade silicon production processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gould, R K; Srivastava, R

    1979-12-01

    Models and computer codes which may be used to describe flow reactors in which high purity, solar grade silicon is produced via reduction of gaseous silicon halides are described. A prominent example of the type of process which may be studied using the codes developed in this program is the SiCl/sub 4//Na reactor currently being developed by the Westinghouse Electric Corp. During this program two large computer codes were developed. The first is the CHEMPART code, an axisymmetric, marching code which treats two-phase flows with models describing detailed gas-phase chemical kinetics, particle formation, and particle growth. This code, based on the AeroChem LAPP (Low Altitude Plume Program) code can be used to describe flow reactors in which reactants mix, react, and form a particulate phase. Detailed radial gas-phase composition, temperature, velocity, and particle size distribution profiles are computed. Also, depositon of heat, momentum, and mass (either particulate or vapor) on reactor walls is described. The second code is a modified version of the GENMIX boundary layer code which is used to compute rates of heat, momentum, and mass transfer to the reactor walls. This code lacks the detailed chemical kinetics and particle handling features of the CHEMPART code but has the virtue of running much more rapidly than CHEMPART, while treating the phenomena occurring in the boundary layer in more detail than can be afforded using CHEMPART. These two codes have been used in this program to predict particle formation characteristics and wall collection efficiencies for SiCl/sub 4//Na flow reactors. Results are described.

  4. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. 76 FR 3084 - Silicon Metal From the People's Republic of China: Final Results and Partial Rescission of the...

    Science.gov (United States)

    2011-01-19

    ... this order. This order is not limited to silicon metal used only as an alloy agent or in the chemical... Silicon Co., Ltd. (``Datong Jinneng''),\\1\\ Jiangxi Gangyuan Silicon Industry Co., Ltd. (``Jiangxi Gangyuan... abbreviation ``Ltd.'' should have been used. \\2\\ We have used the abbreviation ``Co.'' rather than ``Company...

  6. 75 FR 62765 - Silicon Metal From the People's Republic of China; Extension of Time Limit for the Final Results...

    Science.gov (United States)

    2010-10-13

    ... International Trade Administration Silicon Metal From the People's Republic of China; Extension of Time Limit...'') initiated the administrative review (``AR'') of the antidumping duty order on silicon metal from the People... (July 29, 2009). On July 15, 2010, the Department published its preliminary results. See Silicon Metal...

  7. Amorphous silicon research. Final technical progress report, 1 August 1994--28 February 1998

    Energy Technology Data Exchange (ETDEWEB)

    Guha, S [United Solar Systems Corp., Troy, MI (United States)

    1998-05-01

    This report describes the status and accomplishments of work performed under this subcontract by United Solar Systems. United Solar researchers explored several new deposition regimes/conditions to investigate their effect on material/device performance. To facilitate optimum ion bombardment during growth, a large parameter space involving chamber pressure, rf power, and hydrogen dilution were investigated. United Solar carried out a series of experiments using discharge modulation at various pulsed-plasma intervals to study the effect of Si-particle incorporation on solar cell performance. Hydrogen dilution during deposition is found to improve both the initial and stable performance of a-Si and a-SiGe alloy cells. Researchers conducted a series of temperature-ramping experiments on samples prepared with high and low hydrogen dilutions to study the effect of hydrogen effusion on solar cell performance. Using an internal photoemission method, the electrical bandgap of a microcrystalline p layer used in high-efficiency solar cells was measured to be 1.6 eV. New measurement techniques were developed to evaluate the interface and bulk contributions of losses to solar cell performance. Researchers replaced hydrogen with deuterium and found deuterated amorphous silicon alloy solar cells exhibit reduced light-induced degradation. The incorporation of a microcrystalline n layer in a multijunction cell is seen to improve cell performance. United Solar achieved a world-record single-junction a-Si alloy stable cell efficiency of 9.2% with an active area of 0.25 cm{sup 2} grown with high hydrogen dilution. They also achieved a world-record triple-junction, stable, active-area cell efficiency of 13.0% with an active area of 0.25 cm{sup 2}.

  8. Simulation of V/G During Φ450 mm Czochralski Grown Silicon Single Crystal Growth Under the Different Crystal and Crucible Rotation Rates

    National Research Council Canada - National Science Library

    Guan X J; Zhang X Y

    2016-01-01

    ... of Φ450 mm Czochralski grown silicon single crystal (shortly called Cz silicon crystal), the effects of crystal rotation rate and crucible one on the V/G ratio were simulated by using CGSim software...

  9. Polyhydroxyalkanoates accumulation by Methylobacterium organophilum CZ-2 during methane degradation using citrate or propionate as cosubstrates.

    Science.gov (United States)

    Zuñiga, Cristal; Morales, Marcia; Revah, Sergio

    2013-02-01

    Methylobacterium organophilum CZ-2 synthesized polyhydroxyalkanoates (PHAs) under nitrogen limitation with CH4 as carbon source and when either citrate or propionate was added as cosubstrates. The highest PHAs content (yPHA) in closed flasks was obtained in the CH4-citrate and CH4-propionate experiments attaining values of 0.82 and 0.68, respectively. M. organophilum CZ-2 cultivated in bioreactors with citrate and continuous CH4 addition yielded a final PHAs concentration of 143 gm(-3) containing hydroxybutyrate (HB), hydroxyvalerate (HV) and hydroxyoctanoate (HO), in a 55:35:10 ratio, with, yPHA of 0.88 and a CH4 elimination capacity (EC) of 20 gm(-3) h(-1). With propionate, the yPHA was 0.3 and the EC around 8 gm(-3) h(-1). From 1H and 13C NMR experiments it was found that the polymer produced with CH4-citrate contained six different monomers: 3HB, 3HV, 4HV, 4-hydroxyheptanoate (4HH), 3HO and 4HO, showing the great versatility of this PHAs producing bacterium. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. First Measurement of Beam-Recoil Observables Cx and Cz

    Energy Technology Data Exchange (ETDEWEB)

    R. Bradford; R.A. Schumacher; G. Adams; M.J. Amaryan; P. Ambrozewicz; E. Anciant; M. Anghinolfi; B. Asavapibhop; G. Asryan; G. Audit; H. Avakian; H. Bagdasaryan; N. Baillie; J.P. Ball; N.A. Baltzell; S. Barrow; V. Batourine; M. Battaglieri; K. Beard; I. Bedlinskiy; M. Bektasoglu; M. Bellis; N. Benmouna; B.L. Berman; N. Bianchi; A.S. Biselli; B.E. Bonner; S. Bouchigny; S. Boiarinov; D. Branford; W.J. Briscoe; W.K. Brooks; S. B¨ultmann; V.D. Burkert; C. Butuceanu; J.R. Calarco; S.L. Careccia; D.S. Carman; B. Carnahan; S. Chen; P.L. Cole; A. Coleman; P. Collins; P. Coltharp; D. Cords; † P. Corvisiero; D. Crabb; H. Crannell; V. Crede; J.P. Cummings; R. De Masi; E. De Sanctis; R. De Vita; P.V. Degtyarenko; H. Denizli; L. Dennis; A. Deur; K.V. Dharmawardane; R. Dickson; C. Djalali; G.E. Dodge; J. Donnelly; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; O.P. Dzyubak; H. Egiyan; ; K.S. Egiyan; L. El Fassi; L. Elouadrhiri; A. Empl; P. Eugenio; R. Fatemi; G. Fedotov; G. Feldman; R.J. Feuerbach; T.A. Forest; H. Funsten; M. Garcon; G. Gavalian; ; G.P. Gilfoyle; K.L. Giovanetti; F.X. Girod; J.T. Goetz; A. Gonenc; R.W. Gothe; K.A. Griffioen; M. Guidal; M. Guillo; N. Guler; L. Guo; V. Gyurjyan; C. Hadjidakis; K. Hafidi; H. Hakobyan; R.S. Hakobyan; J. Hardie; D. Heddle; F.W. Hersman; K. Hicks; I. Hleiqawi; M. Holtrop; J. Hu; M. Huertas; C.E. Hyde-Wright; Y. Ilieva; D.G. Ireland; B.S. Ishkhanov; E.L. Isupov; M.M. Ito; D. Jenkins; H.S. Jo; K. Joo; H.G. Juengst; N. Kalantarians; J.D. Kellie; M. Khandaker; K.Y. Kim; K. Kim; W. Kim; A. Klein; F.J. Klein; M. Klusman; M. Kossov; L.H. Kramer; V. Kubarovsky; J. Kuhn; S.E. Kuhn; S.V. Kuleshov; J. Lachniet; J.M. Laget; J. Langheinrich; D. Lawrence; A.C.S. Lima; K. Livingston; H.Y. Lu; K. Lukashin; M. MacCormick; J.J. Manak; C. Marchand; N. Markov; S. McAleer; B. McKinnon; J.W.C. McNabb; B.A. Mecking; M.D. Mestayer; C.A. Meyer; T. Mibe; K. Mikhailov; M. Mirazita; R. Miskimen; V. Mokeev; K. Moriya; S.A. Morrow; M. Moteabbed; V. Muccifora; J. Mueller; G.S. Mutchler; P. Nadel-Turonski; J. Napolitano; R. Nasseripour; N. Natasha; S. Niccolai; G. Niculescu; I. Niculescu; B.B. Niczyporuk; M.R. Niroula; R.A. Niyazov; M. Nozar; G.V. O’Rielly; M. Osipenko; A.I. Ostrovidov; K. Park; E. Pasyuk; C. Paterson; S.A. Philips; J. Pierce; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; I. Popa; S. Pozdniakov; B.M. Preedom; J.W. Price; Y. Prok; D. Protopopescu; L.M. Qin; B.P. Quinn; B.A. Raue; G. Riccardi; G. Ricco; M. Ripani; B.G. Ritchie; F. Ronchetti; G. Rosner; P. Rossi; D. Rowntree; P.D. Rubin; F. Sabatie; J. Salamanca; C. Salgado; J.P. Santoro; ; V. Sapunenko; V.S. Serov; A. Shafi; Y.G. Sharabian; J. Shaw; N.V. Shvedunov; S. Simionatto; A.V. Skabelin; E.S. Smith; L.C. Smith; D.I. Sober; D. Sokhan; M. Spraker; A. Stavinsky; S.S. Stepanyan; S. Stepanyan; B.E. Stokes; P. Stoler; I.I. Strakovsky; S. Strauch; M. Taiuti; S. Taylor; D.J. Tedeschi; U. Thoma; R. Thompson; A. Tkabladze; S. Tkachenko; L. Todor; C. Tur; M. Ungaro; M.F. Vineyard; A.V. Vlassov; K. Wang; D.P. Watts; L.B. Weinstein; H. Weller; D.P. Weygand; M. Williams; E. Wolin; M.H. Wood; A. Yegneswaran; J. Yun; L. Zana; J. Zhang; B. Zhao; and Z.W. Zhao

    2007-03-01

    Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $\\vec\\gamma + p \\to K^+ + \\vec\\Lambda$ and $\\vec\\gamma + p \\to K^+ + \\vec\\Sigma^0$. The data were obtained using the CLAS detector at Jefferson Lab for center-of-mass energies $W$ between 1.6 and 2.53 GeV, and for $-0.85<\\cos\\theta_{K^+}^{c.m.}< +0.95$. For the $\\Lambda$, the polarization transfer coefficient along the photon momentum axis, $C_z$, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient, $C_x$, is smaller than $C_z$ by a roughly constant difference of unity. Most significantly, the {\\it total} $\\Lambda$ polarization vector, including the induced polarization $P$, has magnitude consistent with unity at all measured energies and production angles when the beam is fully polarized. For the $\\Sigma^0$ this simple phenomenology does not hold. All existing hadrodynamic models are in poor agreement with these results.

  11. Eutanazja. Potwierdzenie czy zaprzeczenie człowieczeństwa?

    OpenAIRE

    Kosowicz, Marcel

    2015-01-01

    Rozwój cywilizacji wpływa na jakość życia człowieka. Wraz z postępującymi przemianami pojawiają się pytania o moralność oraz godność ludzi. Zmianie ulegają także poglądy nt. eutanazji. Kościół, lekarze czy filozofowie w odmienny sposób motywują swoje stanowiska. Bez względu na przytaczane opinie i argumenty, eutanazja jest naruszeniem wartości życia. Zgoda na takie i inne działania powoduje erozję systemu wartości. Powoduje brak kontroli oraz niewiedzę, kiedy powiedzieć stop. The developme...

  12. 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.)

  13. La varias veces pionera Capilla Bakócz = The several times pioneer chapel Bakócz

    Directory of Open Access Journals (Sweden)

    Laura Corrales Pérez

    2014-12-01

    Full Text Available Resumen Levantada a principios del siglo XVI en Esztergom, la capilla  funeraria del cardenal Tamás Bakócz se aleja del gótico  dominante para constituir el ejemplo más precoz y depurado de arquitectura renacentista al norte de los Alpes. Prematuramente próxima a sus contemporáneos italianos, se vio influenciada por la procedencia artística de sus maestros constructores, y por la poderosa figura de su mecenas y su estrecha relación con el papa Julio II, embarcado en la concepción de la nueva basílica  vaticana. Relevante es también su historia tras la muerte de su patrón. Tras sobrevivir ilesa a casi 150 años de dominación  otomana, fue objeto a comienzos del siglo XIX de una  impresionante y pionera operación de despiece y traslado que aún hoy sigue sorprendiendo por su contemporánea concepción sobre el valor de lo monumental. Abstract Built in the first decade of the 16th century in the Hungarian city of Esztergom, the burial chapel of Cardinal Tamás Bakócz  abandoned the dominant Gothic style to constitute the earliest and most perfect example of Renaissance architecture north of the Alps. Surprisingly close to Italian examples from the same period, this Hungarian building was strongly conditioned by the artistic background of its building masters. However, its main influence came from the leading figure of the Cardinal and his close relationship with the Pope Julius II, who was working at that time in the project for the new Vatican basilica. It is also highly relevant the evolution of the chapel after Bakócz's death. It survived to 150 years of Turkish occupation before being cut into pieces and transferred to a new place. This pioneer process took place in the early beginning of XIX century and is still surprising for the modern concept about restoration that it involves.

  14. Hot forming of silicon sheet, silicon sheet growth development for the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project. Final report, May 12, 1976--August 11, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Jr, C D; Pope, D P; Kulkarni, S

    1978-04-14

    Results of an experimental program investigating the hot workability of polytextuerystalline silicon are reported. Uniaxial stress-strain curves are given for strain rates in the range of 10/sup -5/ to 10/sup 1/ sec/sup -1/ and temperatures from 1100 to 1380/sup 0/C. At the highest strain rates at 1380/sup 0/C axial strains in excess of 20% were easily obtainable without cracking; although special preparation of the compression platens allows strains in excess of 50%. After deformations of 36%, recrystallization is completed within 0.1 hr at 1380/sup 0/C. When the recrystallization is ''complete,'' there is still a small volume fraction of unrecrystallized material which appears very stable and may degrade the electronic properties of the bulk material. Texture measurements show that the as-produced vapor deposited polycrystalline rods have a <110> fiber texture with the <110> direction parallel to the growth direction and no preferred orientation about this axis. Upon axial compression perpendicular to the growth direction the former <110> fiber axis changes to <111> and the compression axis becomes <110>. Recrystallization changes the texture to <110> along the former fiber axis and <100> along the compression axis.

  15. Dependence of Precipitation Behavior of Cu and Ni in CZ Multicrystalline Silicon on Cooling Conditions: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Istratov, A. A.; Buonassisi, T.; Marcus, M. A.; Ciszek, T. F.; Weber, E. R.

    2004-08-01

    The objective of this study was to investigate the size, chemical state, and spatial distribution of metal clusters formed in substantially different cooling conditions of the samples. All samples were scratched on the back with Fe, Cu, and Ni wires and annealed at 1200 C for 2.5 hours in forming gas (N2+5% H2 ambient).

  16. Data of evolutionary structure change: 1CZ7B-2REPA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CZ7B-2REPA 1CZ7 2REP B A ELETCKEQLFQSNMERKELHNTVMDLRGNIRVFCRIRPPLESEENRMCCTWTYH--...2REP A 2REPA LLLFPSDPPTRL...2REP A 2REPA EGGPGGDPQLEGLI...2REP A 2REPA LLATG---CEIRR...2REP A 2REPA EIRRA---SEELT

  17. Data of evolutionary structure change: 1CZ7C-2REPA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CZ7C-2REPA 1CZ7 2REP C A ALSTEVVHLRQRTEELLRCNEQQAAELETCKEQLFQSNMERKELHNTVMDLRGNIR...2REP A 2REPA LLLFPSDPPTRL...2REP A 2REPA EGGPGGDPQLEGLI...2REP A 2REPA LLATG---CEIRR...2REP A 2REPA EIRRA---SEELT

  18. Data of evolutionary structure change: 1CZ7D-2REPA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CZ7D-2REPA 1CZ7 2REP D A LSTEVVHLRQRTEELLRCNEQQAAELETCKEQLFQSNMERKELHNTVMDLRGNIRV...2REP A 2REPA LLLFPSDPPTRL...2REP A 2REPA EGGPGGDPQLEGLI...2REP A 2REPA LLATG---CEIRR...2REP A 2REPA EIRRA---SEELT

  19. Data of evolutionary structure change: 1CZ7A-2REPA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CZ7A-2REPA 1CZ7 2REP A A ELETCKEQLFQSNMERKELHNTVMDLRGNIRVFCRIRPPLESEENRMCCTWTYH--...2REP A 2REPA LLLFPSDPPTRL...2REP A 2REPA EGGPGGDPQLEGLI...2REP A 2REPA EIRRA---SEELT...2REP A 2REPA QNRAV-----ARRSS

  20. Analytical and experimental evaluation of joining silicon nitride to metal and silicon carbide to metal for advanced heat engine applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S.; Selverian, J.H.; O`Neil, D.; Kim, H. [GTE Labs., Inc., Waltham, MA (US); Kim, K. [Brown Univ., Providence, RI (US). Div. of Engineering

    1993-05-01

    This report summarizes the results of Phase 2 of Analytical and Experimental Evaluation of Joining Silicon Nitride to Metal and Silicon Carbide to Metal for Advanced Heat Engine Applications. A general methodology was developed to optimize the joint geometry and material systems for 650{degrees}C applications. Failure criteria were derived to predict the fracture of the braze and ceramic. Extensive finite element analyses (FEA) were performed to examine various joint geometries and to evaluate the affect of different interlayers on the residual stress state. Also, material systems composed of coating materials, interlayers, and braze alloys were developed for the program based on the chemical stability and strength of the joints during processing, and service. The FEA results were compared with experiments using two methods: (1) an idealized strength relationship of the ceramic, and (2) a probabilistic analysis of the ceramic strength (NASA CARES). The results showed that the measured strength of the joint reached 30--80% of the strength predicted by FEA. Also, potential high-temperature braze alloys were developed and evaluated for the high-temperature application of ceramic-metal joints. 38 tabs, 29 figs, 20 refs.

  1. Silicon-Film(TM) Solar Cells by a Flexible Manufacturing System: Final Report, 16 April 1998 -- 31 March 2001

    Energy Technology Data Exchange (ETDEWEB)

    Rand, J.

    2002-02-01

    This report describes the overall goal to engineer and develop flexible manufacturing methods and equipment to process Silicon-Film solar cells and modules. Three major thrusts of this three-year effort were to: develop a new larger-area (208 mm x 208 mm) Silicon-Film solar cell, the APx-8; construct and operate a new high-throughput wafer-making system; and develop a 15-MW single-thread manufacturing process. Specific technical accomplishments from this period are: Increase solar cell area by 80%, increase the generation capacity of a Silicon-Film wafer-making system by 350%, use a new in-line HF etch system in solar cell production, design and develop an in-line NaOH etch system, eliminate cassettes in solar cell processing, and design a new family of module products.

  2. Heat exchanger-ingot casting/slicing process. Silicon sheet growth development for the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project. Final report, Phase I, November 20, 1975--November 20, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, F; Khattak, C P

    1977-12-01

    The proof of concept for silicon casting by the Heat Exchanger Method has been established. One of the major hurdles of ingot cracking has been eliminated with the development of graded crucibles. Such crucibles are compatible with the casting process in that the integrity of the container is maintained at high temperature; however, during the cool-down cycle the crucible fails, thereby leaving a crack-free boule. The controlled growth, heat-flow and cool-down has yielded silicon with a high degree of single crystallinity. Even when the seed melted out, very large grains formed. Solar cell samples made from cast material have yielded conversion efficiency of over 9% (AMI). Representative characterizations of silicon grown has demonstrated a dislocation density of less than 100/cm/sup 2/ and a minority carrier diffusion length of 31 ..mu..m. Excellent surface quality, i.e., surface smoothness and 3 to 5 ..mu..m surface damage, was achieved by multiple wire slicing with fixed diamond abrasive. To achieve this, the silicon workpiece was non-synchronously rocked to produce a radial cut profile and minimize wire contact length. Wire wander was reduced an order of magnitude over the original results by supporting and guiding the wires with grooved rollers. Commercially available impregnated wires that were used failed due to diamond pull-out. Plating after impregnation or electroplating diamonds directly on the core minimized diamond pull-out and corresponding loss in cutting effectiveness. Tungsten wire was the best core material tested because of its high strength, high Young's modulus, and resistance to hydrogen embrittlement. A lighter and longer blade carriage can be used for slicing with wire. This will allow the blade carriage to be reciprocated more rapidly to increase the surface speed. A projected add-on cost calculation shows that these methods will yield silicon for solar cell applications within ERDA/JPL cost goals.

  3. High Volume Manufacturing of Silicon-Film Solar Cells and Modules; Final Subcontract Report, 26 February 2003 - 30 September 2003

    Energy Technology Data Exchange (ETDEWEB)

    Rand, J. A.; Culik, J. S.

    2005-10-01

    The objective of the PV Manufacturing R&D subcontract was to continue to improve AstroPower's technology for manufacturing Silicon-Film* wafers, solar cells, and modules to reduce costs, and increase production yield, throughput, and capacity. As part of the effort, new technology such as the continuous back metallization screen-printing system and the laser scribing system were developed and implemented. Existing processes, such as the silicon nitride antireflection coating system and the fire-through process were optimized. Improvements were made to the statistical process control (SPC) systems of the major manufacturing processes: feedstock preparation, wafer growth, surface etch, diffusion, and the antireflection coating process. These process improvements and improved process control have led to an increase of 5% relative power, and nearly 15% relative improvement in mechanical and visual yield.

  4. Homogenization of CZ Si wafers by Tabula Rasa annealing

    Energy Technology Data Exchange (ETDEWEB)

    Meduna, M., E-mail: mjme@physics.muni.c [Department of Condensed Matter Physics, Masaryk University, Kotlarska 2, CZ-61137 Brno (Czech Republic); Caha, O.; Kubena, J.; Kubena, A. [Department of Condensed Matter Physics, Masaryk University, Kotlarska 2, CZ-61137 Brno (Czech Republic); Bursik, J. [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, CZ-61662 Brno (Czech Republic)

    2009-12-15

    The precipitation of interstitial oxygen in Czochralski grown silicon has been investigated by infrared absorption spectroscopy, chemical etching, transmission electron microscopy and X-ray diffraction after application of homogenization annealing process called Tabula Rasa. The influence of this homogenization step consisting in short time annealing at high temperature has been observed for various temperatures and times. The experimental results involving the interstitial oxygen decay in Si wafers and absorption spectra of SiO{sub x} precipitates during precipitation annealing at 1000 deg. C were compared with other techniques for various Tabula Rasa temperatures. The differences in oxygen precipitation, precipitate morphology and evolution of point defects in samples with and without Tabula Rasa applied is evident from all used experimental techniques. The results qualitatively correlate with prediction of homogenization annealing process based on classical nucleation theory.

  5. Floating Substrate Process. Large-Area Silicon Sheet Task, Low-Cost Solar Array Project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Garfinkel, M.; Hall, R.N.

    1978-06-23

    The work described was directed toward the demonstration of the practical feasibility of the Floating Substrate Process for the growth of silicon sheet. Supercooling of silicon--tin alloy melts was studied. Values as high as 78/sup 0/C at 1100/sup 0/C and 39/sup 0/C at 1200/sup 0/C were observed, corresponding to supersaturation parameter values 0.025 and 0.053 at 1050/sup 0/C and 1150/sup 0/C, respectively. The interaction of tin with silane gas streams was investigated over the temperature range 1000 to 1200/sup 0/C. Single-pass conversion efficiencies exceeding 30% were obtained. The growth habit of spontaneously-nucleated surface growth was determined to be consistent with dendritic and web growth from <111> singly-twinned triangular nucleii. Surface growth of interlocking silicon crystals, thin enough to follow the surface of the liquid and with growth velocity as high as 5 mm/min, was obtained. Large area single-crystal growth along the melt surface was not achieved. Small single-crystal surface growth was obtained which did not propagate beyond a few millimeters. The probable reason for the polycrystalline growth is the poisoning of the growth interface by impurities.

  6. Impurity Precipitation, Dissolution, Gettering and Passivation in PV Silicon: Final Technical Report, 30 January 1998--29 August 2001

    Energy Technology Data Exchange (ETDEWEB)

    Weber, E. R.

    2002-02-01

    This report describes the major progress in understanding the physics of transition metals in silicon and their possible impact on the efficiency of solar cells that was achieved during the three-year span of this subcontract. We found that metal-silicide precipitates and dissolved 3d transition metals can be relatively easily gettered. Gettering and passivating treatments must take into account the individuality of each transition metal. Our studies demonstrated how significant is the difference between defect reactions of copper and iron. Copper does not significantly affect the minority-carrier diffusion length in p-type silicon, at least as long as its concentration is low, but readily precipitates in n-type silicon. Therefore, copper precipitates may form in the area of p-n junctions and cause shunts in solar cells. Fortunately, copper precipitates are present mostly in the chemical state of copper-silicide and can relatively easily be dissolved. In contrast, iron was found to form clusters of iron-oxides and iron-silicates in the wafers. These clusters are thermodynamically stable even in high temperatures and are extremely difficult to remove. The formation of iron-silicates was observed at temperatures over 900C.

  7. High Efficiency Triple-Junction Amorphous Silicon Alloy Photovoltaic Technology, Final Technical Report, 6 March 1998 - 15 October 2001

    Energy Technology Data Exchange (ETDEWEB)

    Guha, S.

    2001-11-08

    This report describes the research program intended to expand, enhance, and accelerate knowledge and capabilities for developing high-performance, two-terminal multijunction amorphous silicon (a-Si) alloy cells, and modules with low manufacturing cost and high reliability. United Solar uses a spectrum-splitting, triple-junction cell structure. The top cell uses an amorphous silicon alloy of {approx}1.8-eV bandgap to absorb blue photons. The middle cell uses an amorphous silicon germanium alloy ({approx}20% germanium) of {approx}1.6-eV bandgap to capture green photons. The bottom cell has {approx}40% germanium to reduce the bandgap to {approx}1.4-eV to capture red photons. The cells are deposited on a stainless-steel substrate with a predeposited silver/zinc oxide back reflector to facilitate light-trapping. A thin layer of antireflection coating is applied to the top of the cell to reduce reflection loss. The major research activities conducted under this program were: (1) Fundamental studies to improve our understanding of materials and devices; the work included developing and analyzing a-Si alloy and a-SiGe alloy materials prepared near the threshold of amorphous-to-microcrystalline transition and studying solar cells fabricated using these materials. (2) Deposition of small-area cells using a radio-frequency technique to obtain higher deposition rates. (3) Deposition of small-area cells using a modified very high frequency technique to obtain higher deposition rates. (4) Large-area cell research to obtain the highest module efficiency. (5) Optimization of solar cells and modules fabricated using production parameters in a large-area reactor.

  8. Fabrication and characterization of ITO/silicon SIS solar cells. Final report, October 1, 1978-April 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    DuBow, J. B.

    1980-06-01

    The objectives of this research were to optimize the performance of ITO/polycrystalline silicon solar cells, identify performance limitations, identify major stability problems which would inhibit terrestrial application of these devices, evaluate the impact of indium supply and price on terrestrial applications, and evaluate the economic viability of ITO sputter deposited solar cells. These goals were successfully achieved during the course of this multipronged effort. Both area scaling with efficiency maintenance were achieved by process modifications including surface preparation and in-situ passivation techniques. Indium tin oxide on Wacker polycrystalline silicon solar cells were fabricated which achieved 13.7% efficiency for 11 cm/sup 2/ devices. Typical open circuit voltages were 0.525 volts, short circuit currents, 34 mA/cm/sup 2/, and fill factors of 0.75. In the course of this project, three device measurement techniques which assisted in improving cell efficiency and which have broad applicability to all photovoltaic devices were introduced. These were automated admittance and surface state analysis, noise spectral density analysis, and automated I-V and C-V analysis. These measurements were combined with Auger/ESCA, EBIC and flying spot scanner, and other measurement techniques to identify grain boundaries, intragrain defects, edge leakage, and interface losses which were subsequently alleviated through process improvements. It is concluded from this work that prototype production of cells and modules based on this technology would be warranted in the near term.

  9. Research on stable, high-efficiency amorphous silicon multijunction modules. Final subcontract report, 1 January 1991--31 August 1994

    Energy Technology Data Exchange (ETDEWEB)

    Guha, S. [United Solar Systems Corp., Troy, MI (United States)

    1994-10-01

    The principal objective of this program is to conduct research on semiconductor materials and non-semiconductor materials to enhance the performance of multibandgap, multijunction, large-area amorphous silicon-based alloy modules. The goal for this program is to demonstrate stabilized module efficiency of 12% for multijunction modules of area greater than 900 cm{sup 2}. Double-junction and triple-junction cells are made on Ag/ZnO back reflector deposited on stainless steel substrates. The top cell uses a-Si alloy; a-SiGe alloy is used for the i layer in the middle and the bottom cells. After evaporation of antireflection coating, silver grids and bus bars are put on the top surface, and the panel is encapsulated in an ethylene vinyl acetate (EVA)/Tefzel structure to make a one-square-foot monolithic module.

  10. Fundamental Research and Development for Improved Crystalline Silicon Solar Cells: Final Subcontract Report, March 2002 - July 2006

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.

    2007-11-01

    This report summarizes the progress made by Georgia Tech in the 2002-2006 period toward high-efficiency, low-cost crystalline silicon solar cells. This program emphasize fundamental and applied research on commercial substrates and manufacturable technologies. A combination of material characterization, device modeling, technology development, and complete cell fabrication were used to accomplish the goals of this program. This report is divided into five sections that summarize our work on i) PECVD SiN-induced defect passivation (Sections 1 and 2); ii) the effect of material inhomogeneity on the performance of mc-Si solar cells (Section 3); iii) a comparison of light-induced degradation in commercially grown Ga- and B-doped Czochralski Si ingots (Section 4); and iv) the understanding of the formation of high-quality thick-film Ag contacts on high sheet-resistance emitters (Section 5).

  11. Large area multicrystalline silicon solar cells with high efficiency. Final report; Grossflaechige multikristalline Silizium-Solarzellen mit hohen Wirkungsraden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Ebest, G.; Erler, K.; Mrwa, A.; Ball, M.

    2001-09-01

    Solar cells were produced of wafers of die-cast and strip-drawn multicrystalline silicon and characterized. Production methods like SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) and screen printing were investigated. The results are summarized as follows: 1. Layer resistance can be adjusted by variation of the RTP temperature cycle and by selecting appropriate doping materials (P507 by Filmtronics); 2. The low resistance required for screen printing metallization are obtained only with a different doping material (P8545SF-Filmtronics); 3. Metallized aluminium and copper require a 30 nm TiN layer as diffusion barrier; 4. Reflectivity will be reduced most effectively by RIE with chlorine gas on monocrystalline and multicrystalline silicon wafers. [German] Im Rahmen des Projektes wurden auf Wafern aus blockgegossenem und bandgezogenem multikristallinen Silizium Solarzellen hergestellt und charakterisiert. Fuer die Herstellung wurden Verfahren wie SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) und Siebdruck untersucht. Die Ergebnisse lassen sich wie folgt zusammenfassen: 1. eine Einstellung des Schichtwiderstandes wird durch Variation des RTP-Temperaturzyklus sowie Auswahl verschiedener Dotierstoffe (P507 von Filmtronics) erreicht; 2. die fuer die Siebdruckmetallisierung erforderlichen geringen Schichtwiderstaende werden nur durch die Wahl eines anderen Dotierstoffes (P8545SF-Filmtronics) erreicht; 3. Aluminium- und Kupfermetallisierungen benoetigen eine 30 nm dicke TiN-Schicht als Diffusionsbarriere; und 4. die wirksamste Verminderung des Reflexionsgrades ist mittels RIE-Verfahren unter Verwendung von Chlorgas auf ein- und multikristalline Siliziumwafer erreichbar.

  12. Research on silicon-carbon alloys and interfaces. Final subcontract report, 15 February 1991--31 July 1994

    Energy Technology Data Exchange (ETDEWEB)

    Abelson, J.R. [Illinois Univ., Urbana, IL (United States)

    1995-07-01

    This report describes work performed to develop improved p-type wide-band-gap hydrogenated amorphous silicon-carbon alloy (a-Si{sub 1-x}C{sub x:}H) thin films and interfaces for the ``top junction`` in hydrogenated amorphous silicon (a-Si:H)-based p-i-n solar cells. We used direct current reactive magnetron sputtering to deposit undoped a-Si{sub 1-x}C{sub x}H films with a Tauc band gap E{sub g} of 1.90 eV, a sub-band-gap absorption of 0.4 (at 1.2 eV), an Urbach energy of 55 MeV, an ambipolar diffusion length of 100 nm, an air-mass-one photoconductivity of 10{sup {minus}6}/{Omega}-cm, and a dark conductivity of 8{times} 1O{sup {minus}11}/{Omega}-cm. p{sup +}a-Si{sub 1-x}C{sub x}:H films with a Tauc band gap of 1.85 eV have a dark conductivity of 8 {times} 10{sup {minus}6}/{Omega}-cm and thermal activation energy of 0.28 eV. We used in-situ spectroscopic ellipsometry and post-growth X-ray photoelectron spectroscopy to determine the relative roles of H and Si in the chemical reduction of SnO{sub 2} in the early stages of film growth. We used in-situ spectroscopic ellipsometry to show that a-Si:H can be transformed into {mu}c-Si:H in a subsurface region under appropriate growth conditions. We also determined substrate cleaning and ion bombardment conditions which improve the adhesion of a-Si{sub 1-x}C{sub x}:H films.

  13. LSA large area silicon sheet task, continuous liquid feed Czochralski growth. Quarterly report No. 4, July--September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Fiegl, G.

    1978-09-01

    Siltec Corporation's contract with JPL is directed towards the design and development of equipment and processes, to demonstrate continuous growth of crystals by the Czochralski method, suitable for producing single silicon crystals for use in solar cells. Continuous growth is defined as the growth of 100 Kg of single silicon crystal, 10 cm in diameter, from one container. Siltec's approach to meeting this goal is to develop a furnace with continuous liquid replenishment of the growth crucible, accomplished by a melt-down system and a liquid transfer mechanism, with associated automatic feedback controls. Fabrication of all furnace parts was completed during the past quarter. Mechanical assembly of the furnace was accomplished and all electrical work completed. The furnace underwent final systems testing and is now ready for test runs. Two crystals from 15 Kg charges were grown by conventional CZ technique. Simulated transfer of molten silicon was performed using a liquid of approximately the same kinematic viscosity as that of molten silicon. A study was made to determine the effects of a stationary 7 mm O.D. quartz tube submerged into the molten silicon in the rotating crucible during the growth of a 2-inch diameter crystal. Results are reported.

  14. Investigation of Backside Textures for Genesis Solar Wind Silicon Collectors

    Science.gov (United States)

    Gonzalez, C. P.; Burkett, P. J.; Rodriguez, M. C.; Allton, J. H.

    2014-01-01

    Genesis solar wind collectors were comprised of a suite of 15 types of ultrapure materials. The single crystal, pure silicon collectors were fabricated by two methods: float zone (FZ) and Czochralski (CZ). Because of slight differences in bulk purity and surface cleanliness among the fabrication processes and the specific vendor, it is desirable to know which variety of silicon and identity of vendor, so that appropriate reference materials can be used. The Czochralski method results in a bulk composition with slightly higher oxygen, for example. The CZ silicon array wafers that were Genesis-flown were purchased from MEMC Electronics. Most of the Genesis-flown FZ silicon was purchased from Unisil and cleaned by MEMC, although a few FZ wafers were acquired from International Wafer Service (IWS).

  15. N-type compensated silicon: resistivity, crystal growth, carrier lifetime, and relevant application for HIT solar cells

    Science.gov (United States)

    Li, Shuai; Gao, Wenxiu; Li, Zhen; Cheng, Haoran; Lin, Jinxia; Cheng, Qijin

    2017-05-01

    N-type compensated silicon shows unusual distribution of resistivity as crystal grows compared to the n-type uncompensated silicon. In this paper, evolutions of resistivities with varied concentrations of boron and varied starting resistivities of the n-type silicon are intensively calculated. Moreover, reduction of carrier mobility is taken into account by Schindler’s modified model of carrier mobility for the calculation of resistivity of the compensated silicon. As for substrates of solar cells, optimized starting resistivity and corresponding concentration of boron are suggested for better uniformity of resistivity and higher yield (fraction with ρ >0.5 ~ Ω \\centerdot \\text{cm} ) of the n-type compensated Cz crystal rod. A two-step growth method is investigated to obtain better uniformity of resistivity of crystal rod, and this method is very practical especially for the n-type compensated silicon. Regarding the carrier lifetime, the recombination by shallow energy-level dopants is taken into account for the compensated silicon, and evolution of carrier lifetime is simulated by considering all main recombination centers which agrees well with our measured carrier lifetimes as crystal grows. The n-type compensated silicon shows a larger reduction of carrier lifetime compared to the uncompensated silicon at the beginning of crystal growth, and recombination with a oxygen-related deep defect is sufficient to describe the reduction of degraded lifetime. Finally, standard heterojunction with intrinsic thin-layer (HIT) solar cells are made with substrates from the n-type compensated silicon rod, and a high efficiency of 22.1% is obtained with a high concentration (0.8× {{10}16}~\\text{c}{{\\text{m}}-3} ) of boron in the n-type compensated silicon feedstock. However, experimental efficiencies of HIT solar cells based on the n-type compensated silicon show an average reduction of 4% along with the crystal length compared to the uncompensated silicon. The

  16. Development of low cost contacts to silicon solar cells. Final report, 15 October 1978-30 April 1980

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, D.P.; Iles, P.A.

    1980-01-01

    A summary of work done on the development of a copper based contact system for silicon solar cells is presented. The work has proceeded in three phases: (1) Development of a copper based contact system using plated Pd-Cr-Cu. Good cells were made but cells degraded under low temperature (300/sup 0/C) heat treatments. (2) The degradation in Phase I was identified as copper migration into the cells junction region. A paper study was conducted to find a proper barrier to the copper migration problem. Nickel was identified as the best candidate barrier and this was verified in a heat treatment study using evaporated metal layers. (3) An electroless nickel solution was substituted for the electroless chrominum solution in the original process. Efforts were made to replace the palladium bath with an appropriate nickel layer, but these were unsuccessful. 150 cells using the Pd-Ni-Cu contact system were delivered to JPL. Also a cost study was made on the plating process to assess the chance of reaching 5 cents/watt.

  17. Product technology and market assessment for silicon carbide whisker reinforced alumina heat-exchanger tubes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Loutfy, R.O.; Withers, J.C. [Materials and Electrochemical Research Corp., Tucson, AZ (United States); Chakravarti, D. [Arizona Univ., Tucson, AZ (United States)

    1993-10-01

    This report describes a study designed to develop an assessment of key performance features, desirable technical specifications and market potential for silicon carbide whisker-reinforced alumina (henceforth SCWRA) tubes for heat exchanger applications in a number of industries. The results of the first stage of a Delphi study conducted in the US market are presented. The second phase of the study is in progress. The first stage results suggest that there is a small market for SCWRA tubes in heat exchanger applications. The market is expected to grow steadily during the 1990`s. With appropriate performance specifications and competitive pricing, growth should come from (a) new applications that permit recovery in cases that were previously infeasible and (b) selective, partial substitution and replacement of current ceramics and metal/ceramic composites in existing applications. We identify key performance factors and detailed specifications needed in six designated industries (primary metals, fabricated metals, chemicals, glass, utility and incinerators). Reliability, durability and low maintenance costs emerge as critical performance factors across these industries. The data show that although ceramics are recognized as having better properties, enhancing reliability and durability and thus improving maintenance cost performance is a key priority. Such improvements, reflected in the objectives for SCWRA tubes, should facilitate adoption in both new and existing applications. At this time, we are unable to assess market size directly. However, expert judgment provided indices tracking the projected market for heat exchanger tubes from 1990 to 2005.

  18. A Novel Non-Destructive Silicon-on-Insulator Nonvolatile Memory - LDRD 99-0750 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    DRAPER,BRUCE L.; FLEETWOOD,D. M.; MEISENHEIMER,TIMOTHY L.; MURRAY,JAMES R.; SCHWANK,JAMES R.; SHANEYFELT,MARTY R.; SMITH,PAUL M.; VANHEUSDEN,KAREL J.; WARREN,WILLIAM L.

    1999-11-01

    Defects in silicon-on-insulator (SOI) buried oxides are normally considered deleterious to device operation. Similarly, exposing devices to hydrogen at elevated temperatures often can lead to radiation-induced charge buildup. However, in this work, we take advantage of as-processed defects in SOI buried oxides and moderate temperature hydrogen anneals to generate mobile protons in the buried oxide to form the basis of a ''protonic'' nonvolatile memory. Capacitors and fully-processed transistors were fabricated. SOI buried oxides are exposed to hydrogen at moderate temperatures using a variety of anneal conditions to optimize the density of mobile protons. A fast ramp cool down anneal was found to yield the maximum number of mobile protons. Unfortunately, we were unable to obtain uniform mobile proton concentrations across a wafer. Capacitors were irradiated to investigate the potential use of protonic memories for space and weapon applications. Irradiating under a negative top-gate bias or with no applied bias was observed to cause little degradation in the number of mobile protons. However, irradiating to a total dose of 100 krad(SiO{sub 2}) under a positive top-gate bias caused approximately a 100% reduction in the number of mobile protons. Cycling capacitors up to 10{sup 4} cycles had little effect on the switching characteristics. No change in the retention characteristics were observed for times up to 3 x 10{sup 4} s for capacitors stored unbiased at 200 C. These results show the proof-of-concept for a protonic nonvolatile memory. Two memory architectures are proposed for a protonic non-destructive, nonvolatile memory.

  19. DML-CZ : the experience of a medium-sized Digital Mathematics Library

    Czech Academy of Sciences Publication Activity Database

    Bartošek, M.; Rákosník, Jiří

    2013-01-01

    Roč. 60, č. 8 (2013), s. 1028-1033 ISSN 0002-9920 Institutional support: RVO:67985840 Keywords : Czech Digital Mathematics Library * DML-CZ * digital libraries Subject RIV: BA - General Mathematics http://www.ams.org/notices/201308/rnoti-p1028.pdf

  20. Intrinsic gettering of Czochralski silicon annealed in argon and nitrogen atmosphere

    Science.gov (United States)

    Shui, Qiong; Yang, Deren; Li, Liben; Pi, Xiaodong; Que, Duanlin

    2001-12-01

    The intrinsic gettering of nitrogen-doped Czochralski (NCZ) and nitrogen-undoped Czochralski (CZ) silicon annealed in argon and nitrogen ambient has been investigated by three-step annealing. It is found that the threshold oxygen concentration for effective precipitation is about 4.8×10 17 cm -3 at 1150°C. No difference of the denuded zone (DZ) width between the NCZ and CZ silicon samples was found when they were annealed in argon ambient. However, a few of small etching pits occurred in the DZ region for both of NCZ and CZ silicon samples. It is suggested that nitrogen could diffuse into the DZ region and form N-O complexes as heterogeneous nuclei, which can enhance oxygen precipitates, when the samples were annealed in nitrogen ambient.

  1. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Final Subcontract Report, 1 April 2002--28 February 2006

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Narayanan, M.

    2006-07-01

    The major objectives of this program were to continue advances of BP Solar polycrystalline silicon manufacturing technology. The Program included work in the following areas. (1) Efforts in the casting area to increase ingot size, improve ingot material quality, and improve handling of silicon feedstock as it is loaded into the casting stations. (2) Developing wire saws to slice 100-..mu..m-thick silicon wafers on 290-..mu..m-centers. (3) Developing equipment for demounting and subsequent handling of very thin silicon wafers. (4) Developing cell processes using 100-..mu..m-thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%. (5) Expanding existing in-line manufacturing data reporting systems to provide active process control. (6) Establishing a 50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology. (7) Facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock..

  2. Implementation of Tunneling Passivated Contacts into Industrially Relevant n-Cz Si Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Nemeth, William; LaSalvia, Vincenzo; Page, Matthew R.; Warren, Emily L.; Dameron, Arrelaine; Norman, Andrew G.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

    2015-06-14

    We identify bottlenecks, and propose solutions, to implement a B-diffused front emitter and a backside pc-Si/SiO2 pasivated tunneling contact into high efficiency n-Cz Si cells in an industrially relevant way. We apply an O-precipitate dissolution treatment to make n-Cz wafers immune to bulk lifetime process degradation, enabling robust, passivated B front emitters with J0 <; 20fA/cm2. Adding ultralow recombination n+ pc-Si/SiO2 back contacts enables pre-metallized cells with iVoc=720 mV and J0=8.6 fA/cm2. However, metallization significantly degrades performance of these contacts due to pinholes and possibly, grain boundary diffusion of primary metal and source contaminates such as Cu. An intermediate, doped a-Si:H capping layer is found to significantly block the harmful metal penetration into pc-Si.

  3. Návrh strategie inbound marketingu pro start-up Stips.cz

    OpenAIRE

    Horáčková, Simona

    2017-01-01

    The aim of this diploma thesis is to analyze and create an inbound marketing strategy for e-shop Stips.cz, which sells experience gifts. The theoretical part includes describing what inbound marketing is and the phases and rules of inbound marketing. In another part many tools of inbound marketing are covered. In the practical part a detailed analysis of visits to the website, competitors, SEO factors and inbound marketing tools is conducted. After the analysis the inbound marketing strategy ...

  4. The biobanking research infrastructure BBMRI_CZ: a critical tool to enhance translational cancer research.

    Science.gov (United States)

    Holub, P; Greplova, K; Knoflickova, D; Nenutil, R; Valik, D

    2012-01-01

    We introduce the national research biobanking infrastructure, BBMRI_CZ. The infrastructure has been founded by the Ministry of Education and became a partner of the European biobanking infrastructure BBMRI.eu. It is designed as a network of individual biobanks where each biobank stores samples obtained from associated healthcare providers. The biobanks comprise long term storage (various types of tissues classified by diagnosis, serum at surgery, genomic DNA and RNA) and short term storage (longitudinally sampled patient sera). We discuss the operation workflow of the infrastructure that needs to be the distributed system: transfer of the samples to the biobank needs to be accompanied by extraction of data from the hospital information systems and this data must be stored in a central index serving mainly for sample lookup. Since BBMRI_CZ is designed solely for research purposes, the data is anonymised prior to their integration into the central BBMRI_CZ index. The index is then available for registered researchers to seek for samples of interest and to request the samples from biobank managers. The paper provides an overview of the structure of data stored in the index. We also discuss monitoring system for the biobanks, incorporated to ensure quality of the stored samples.

  5. Process research of non-CZ silicon material. Quarterly report No. 2, January 1, 1984-March 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R.B.

    1984-05-01

    In this program, which started November 4, 1983, the fabrication of solar cells on N-base material using simultaneous diffusion of liquid boron and phosphorus dopants to from the desired P/sup +/NN/sup +/ cell structure is being studied. This simultaneous junction formation method is being compared to the sequential junction formation method where phosphorus is diffused to form an N/sup +/N back surface field followed by a boron diffusion for the P/sup +/N front junction. During the contract, the sensitivity of the process parameters will also be studied; and a cost analysis of the new junction formation process will be performed using SAMICS-IPEG methodology.

  6. „Rocznik Muzeum Częstochowskiego” w latach 2005-2014. Analiza jakościowa czasopisma naukowego

    Directory of Open Access Journals (Sweden)

    Małgorzata Wrześniewska

    2015-12-01

    Full Text Available Artykuł przedstawia analizę jakościową czasopisma naukowego pt. „Rocznik Muzeum Częstochowskiego” w latach 2005-2014. Jest on kontynuacją artykułu pt. „Rocznik Muzeum Częstochowskiego” w latach 1965-1993. Analiza jakościowa czasopisma naukowego” opublikowanego w 2015 r.

  7. Vliv sociálních medií na společnost Answear cz.

    OpenAIRE

    Zuková, Nela

    2017-01-01

    The dissertation Social Media effect on Answear CZ company focuses on marketing and on-line marketing issues and social media potential in terms of business performance and marketing awareness. In the theoretical part, a marketing and on-line marketing will be defined and described, followed by social media and possibilities of their application in business, such as Facebook, Instagram, Twitter and others. In practical part, a social media strategy of Answear CZ company will be presented, dis...

  8. Online marketingová strategie portálu Divadlo.cz

    OpenAIRE

    Jermářová, Karolína

    2010-01-01

    The objective of this thesis is to propose an online marketing strategy for the Divadlo.cz web portal, which is currently undergoing a complete redesign including the extension of functions and services provided to its users. The proposed mix of marketing activities should help to increase the target groups' awareness of news on the web and provide the increase of the targeted visit rate. At the same time I focused on the possibilities of the increase of the web conversion ratio and, on the b...

  9. Ocenění firmy ELIT CZ, spol. s r.o.

    OpenAIRE

    Nováková, Lucie

    2016-01-01

    This thesis deals with methods and options of valuation of companies, valuation process and everything that goes with it. An integral part of the strategic analysis is financial analysis and financial plan to years 2016 - 2020. For the financial analysis following methods have been used: vertical and horizontal analysis, a ratio indexes and the balancing rules. The financial plan has been drawn up by value generators. The aim is to valuate a specific company ELIT CZ, Ltd., which is engaged in...

  10. Phase 2 of the automated array assembly task of the low-cost silicon solar array project. Final report, 1 April 1979-31 March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, M.G.; Pryor, R.A.; Sparks, T.G.; Legge, R.M.; Saltzman, D.L.

    1980-01-01

    Several specific processing steps, as part of a total process sequence for manufacturing silicon solar cells, were studied during this contract. Ion implantation has been identified as the Motorola preferred process step for impurity doping. Unanalyzed beam ion implantation has been shown to have major cost advantages over analyzed beam implantation. Further, high quality cells have been fabricated using a high current unanalyzed beam. Mechanically masked plasma patterning of silicon nitride has been shown to be capable of forming fine lines on silicon surfaces with spacings between mask and substrate as great as 250 ..mu..m (10 mils). Extensive work was performed on advances in plated metallization. The need for the thick electroless palladium layer has been eliminated. Further, copper has been successfully utilized as a conductor layer, utilizing nickel as a barrier to copper diffusion into the silicon. Plasma etching of silicon for texturing and saw damage removal has been shown technically feasible, but not cost-effective compared to wet chemical etching techniques.

  11. Light management in large area thin-film silicon solar modules

    Czech Academy of Sciences Publication Activity Database

    Losio, P.A.; Caglar, O.; Cashmore, J.S.; Hötzel, J.E.; Ristau, S.; Holovský, Jakub; Remeš, Zdeněk; Sinicco, I.

    2015-01-01

    Roč. 143, Dec (2015), s. 375-385 ISSN 0927-0248 R&D Projects: GA ČR(CZ) GA14-05053S Institutional support: RVO:68378271 Keywords : micromorph * thin-film silicon solar cells * light management * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.732, year: 2015

  12. Silicon applications in photonics

    Science.gov (United States)

    Jelenski, A. M.; Gawlik, G.; Wesolowski, M.

    2005-09-01

    Silicon technology enabled the miniaturization of computers and other electronic system for information storage, transmission and transformation allowing the development of the Knowledge Based Information Society. Despite the fact that silicon roadmap indicates possibilities for further improvement, already now the speed of electrons and the bandwidth of electronic circuits are not sufficient and photons are commonly utilized for signal transmission through optical fibers and purely photonic circuits promise further improvements. However materials used for these purposes II/V semiconductor compounds, glasses make integration of optoelectronic circuits with silicon complex an expensive. Therefore research on light generation, transformation and transmission in silicon is very active and recently, due to nanotechnology some spectacular results were achieved despite the fact that mechanisms of light generation are still discussed. Three topics will be discussed. Porous silicon was actively investigated due to its relatively efficient electroluminescence enabling its use in light sources. Its index of refraction, differs considerably from the index of silicon, and this allows its utilization for Bragg mirrors, wave guides and photonic crystals. The enormous surface enables several applications on medicine and biotechnology and in particular due to the effective chemo-modulation of its refracting index the design of optical chemosensors. An effective luminescence of doped and undoped nanocrystalline silicon opened another way for the construction of silicon light sources. Optical amplification was already discovered opening perspectives for the construction of nanosilicon lasers. Luminescences was observed at red, green and blue wavelengths. The used technology of silica and ion implantation are compatible with commonly used CMOS technology. Finally the recently developed and proved idea of optically pumped silicon Raman lasers, using nonlinearity and vibrations in the

  13. Near infrared photoluminescence of the hydrogenated amorphous silicon thin films with in-situ embedded silicon nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Remeš, Zdeněk; Stuchlík, Jiří; Purkrt, Adam; Ledinský, Martin; Kupčík, Jaroslav

    2017-01-01

    Roč. 61, č. 2 (2017), s. 136-140 ISSN 0862-5468 R&D Projects: GA ČR GC16-10429J Grant - others:AV ČR(CZ) KONNECT-007 Program:Bilaterální spolupráce Institutional support: RVO:68378271 ; RVO:61388980 Keywords : amorphous silicon * chemical vapor deposition * photothermal deflection spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.439, year: 2016

  14. Particle detectors made of high-resistivity Czochralski silicon

    CERN Document Server

    Härkönen, J; Ivanov, A; Li, Z; Luukka, Panja; Pirojenko, A; Riihimaki, I; Tuominen, E; Tuovinen, E; Verbitskaya, E; Virtanen, A

    2005-01-01

    We have processed pin-diodes and strip detectors on n- and p-type high-resistivity silicon wafers grown by magnetic Czochralski method. The Czochralski silicon (Cz-Si) wafers manufactured by Okmetic Oyj have nominal resistivity of 900 Omega cm and 1.9 kOmega cm for n- and p-type, respectively. The oxygen concentration in these substrates is slightly less than typically in wafers used for integrated circuit fabrication. This is optimal for semiconductor fabrication as well as for radiation hardness. The radiation hardness of devices has been investigated with several irradiation campaigns including low- and high-energy protons, neutrons, gamma-rays, lithium ions and electrons. Cz-Si was found to be more radiation hard than standard Float Zone silicon (Fz-Si) or oxygenated Fz-Si. When irradiated with protons, the full depletion voltage in Cz-Si has not exceeded its initial value of 300 V even after the fluence of 5 multiplied by 10**1**4 cm**-**2 1-MeV eq. n cm **-**2 that equals more than 30 years operation of...

  15. Efficiency of commercial Cz-Si solar cell with a shallow emitter

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, C.; Alonso, J.; Vazquez, M.A.; Caballero, L.J. [Isofoton S.A., c/Severo Ochoa 50, PTA, 29590 Malaga (Spain); Romero, R. [Laboratorio de Materiales y Superficie (Unidad asociada al CSIC), Dpto. Fisica Aplicada Facultad de Ciencias, Universidad de Malaga, E29071 Malaga (Spain); Ramos-Barrado, J.R., E-mail: barrado@uma.es [Laboratorio de Materiales y Superficie (Unidad asociada al CSIC), Dpto. Fisica Aplicada Facultad de Ciencias, Universidad de Malaga, E29071 Malaga (Spain)

    2010-08-15

    The increase of a commercial solar cell performance implies an improvement in the different processes in the industrial production. In order to know the main limitations in the efficiency of Czocharalski-Si (Cz-Si) photovoltaic cells, the loss distribution was studied by means of external quantum efficiency, I-V measurements and PC-1D simulation in the current device. One of the most relevant losses is due to recombination in the emitter. The emitters with a low resistance (40 {Omega}/{open_square}) and a deep pn-junction, display a considerable loss ratio. Shallower emitters (80 {Omega}/{open_square}) with low doping density and a new paste for the front side result in a relative improvement in cell efficiency of 3.5%.

  16. Collection and conversion of silicon furnace waste gas into higher value products: Phase 3, 6 MW pilot plant dc closed furnace technology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dosaj, V.D.

    1995-01-01

    The construction and operation of a 6 MW, closed dc furnace for smelting silicon was the primary focus of Phase 3. A 6 MW, dc closed furnace pilot plant was built in East Selkirk, Manitoba, Canada. The furnace is equipped with world`s most modern automatic control system used to control and monitor the process variables and operational data. This control system is suitable for commercial applications and could be used with either closed or open dc furnaces for smelting silicon or ferrosilicon. The construction was started in September 1990, and the facility was operational within 18 months. Following successful commissioning of the pilot plant in June 1992, twelve smelting test campaigns were conducted through November 1994.

  17. Nutritional Requirements for the Mycelial Biomass and Exopolymer Production by Hericium erinaceus CZ-2

    Directory of Open Access Journals (Sweden)

    Daming Huang

    2007-01-01

    Full Text Available In this work, the effects of medium composition and fermentation parameters on the simultaneous production of mycelial biomass and exopolymer by medicinal mushroom Hericium erinaceus CZ-2 were investigated in shake flask cultures using one-factor-at-a-time method and orthogonal array design. Results showed that the most suitable carbon, nitrogen, mineral sources, and cofactors for the mycelial biomass and exopolymer production were: corn flour combined with 1 % glucose, yeast extract, KH2PO4 and corn steep liquor. The intuitive analysis of orthogonal array design results indicated that the effects of nutritional requirement on the mycelial growth of Hericium erinaceus CZ-2 were in regular sequence of corn flour combined with 1 % glucose > yeast extract > corn steep liquor > KH2PO4, and those on exopolymer production were in the order of corn flour combined with glucose > KH2PO4 > yeast extract > corn steep liquor. The maximal yield of mycelial biomass (16.07 g/L was obtained when the composition of the culture medium was (in g/L: corn flour 30, glucose 10, yeast extract 3, KH2PO4 1, CaCO3 0.5, and 15 mL/L of corn steep liquor; while the maximal exopolymer yield (1.314 g/L was achieved when the composition of medium was (in g/L: corn flour 30, glucose 10, yeast extract 5, KH2PO4 3, CaCO3 0.5, and 15 mL/L of corn steep liquor. In the 15-litre scale-up fermentation, the maximum mycelial biomass yield of 20.50 g/L was achieved using the optimized medium.

  18. Spatial Pattern of Copper Phosphate Precipitation Involves in Copper Accumulation and Resistance of Unsaturated Pseudomonas putida CZ1 Biofilm.

    Science.gov (United States)

    Chen, Guangcun; Lin, Huirong; Chen, Xincai

    2016-12-28

    Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a 75 μm thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling Cu₃(PO₄)₂ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were Cu₃(PO₄)₂-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% Cu₃(PO₄)₂, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.

  19. The Electroluminescence Mechanism of Solution-Processed TADF Emitter 4CzIPN Doped OLEDs Investigated by Transient Measurements

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2016-10-01

    Full Text Available High efficiency, solution-processed, organic light emitting devices (OLEDs, using a thermally-activated delayed fluorescent (TADF emitter, 1,2,3,5-tetrakis(carbazol-9-yl-4,6-dicyanobenzene (4CzIPN, are fabricated, and the transient electroluminescence (EL decay of the device with a structure of [ITO/PEDOT: PSS/4CzIPN 5 wt % doped 4,40-N,N0-dicarbazolylbiphenyl(CBP/bis-4,6-(3,5-di-4-pyridylphenyl-2-methylpyrimidine (B4PyMPM/lithium fluoride (LiF/Al], is systematically studied. The results shed light on the dominant operating mechanism in TADF-based OLEDs. Electroluminescence in the host–guest system is mainly produced from the 4CzIPN emitter, rather than the exciplex host materials.

  20. 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.

  1. Medium-Range Order in Amorphous Silicon Measured by Fluctuation Electron Microscopy: Final Report, 23 June 1999--23 August 2002

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, P. M.; Abelson, J. R.

    2003-10-01

    Despite occasional experimental hints, medium-range structural order in covalently bonded amorphous semiconductors had largely escaped detection until the advent of fluctuation electron microscopy (FEM) in 1996. Using FEM, we find that every sample of amorphous silicon and germanium we have investigated, regardless of deposition method or hydrogen content, is rich in medium-range order. The paracrystalline structural model, which consists of small, topologically ordered grains in an amorphous matrix, is consistent with the FEM data; but due to strain effects, materials with a paracrystalline structure appear to be amorphous in diffraction measurements. We present measurements on hydrogenated amorphous silicon deposited by different methods, some of which are reported to have greater stability against the Staebler-Wronski effect. FEM reveals that the matrix material of these samples is relatively similar, but the order changes in different ways upon both light soaking and thermal annealing. Some materials are inhomogeneous, with either nanocrystalline inclusions or large area-to-area variation in the medium-range order. We cite recent calculations that electronic states in the conduction band tail are preferentially located around the boundaries of the nm-scale paracrystalline regions that we have identified. This is new evidence in support of spatially inhomogeneous conduction mechanisms in a-Si. The key discovery in our work is that all samples of amorphous silicon must be described as having nm-scale topological crystalline order. This strongly modifies the long-standing model of a covalent random network. Our new understanding of medium-range order must be considered in all future models of electronic properties and the Staebler-Wronski effect.

  2. High-Efficiency Amorphous Silicon Alloy Based Solar Cells and Modules; Final Technical Progress Report, 30 May 2002--31 May 2005

    Energy Technology Data Exchange (ETDEWEB)

    Guha, S.; Yang, J.

    2005-10-01

    The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low manufacturing cost and high reliability. Our strategy has been to use the spectrum-splitting triple-junction structure, a-Si:H/a-SiGe:H/a-SiGe:H, to improve solar cell and module efficiency, stability, and throughput of production. The methodology used to achieve the objectives included: (1) explore the highest stable efficiency using the triple-junction structure deposited using RF glow discharge at a low rate, (2) fabricate the devices at a high deposition rate for high throughput and low cost, and (3) develop an optimized recipe using the R&D batch large-area reactor to help the design and optimization of the roll-to-roll production machines. For short-term goals, we have worked on the improvement of a-Si:H and a-SiGe:H alloy solar cells. a-Si:H and a-SiGe:H are the foundation of current a-Si:H based thin-film photovoltaic technology. Any improvement in cell efficiency, throughput, and cost reduction will immediately improve operation efficiency of our manufacturing plant, allowing us to further expand our production capacity.

  3. Modular fabrication and characterization of complex silicon carbide composite structures Advanced Reactor Technologies (ART) Research Final Report (Feb 2015 – May 2017)

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, Hesham [General Atomics, San Diego, CA (United States)

    2017-08-03

    Advanced ceramic materials exhibit properties that enable safety and fuel cycle efficiency improvements in advanced nuclear reactors. In order to fully exploit these desirable properties, new processing techniques are required to produce the complex geometries inherent to nuclear fuel assemblies and support structures. Through this project, the state of complex SiC-SiC composite fabrication for nuclear components has advanced significantly. New methods to produce complex SiC-SiC composite structures have been demonstrated in the form factors needed for in-core structural components in advanced high temperature nuclear reactors. Advanced characterization techniques have been employed to demonstrate that these complex SiC-SiC composite structures provide the strength, toughness and hermeticity required for service in harsh reactor conditions. The complex structures produced in this project represent a significant step forward in leveraging the excellent high temperature strength, resistance to neutron induced damage, and low neutron cross section of silicon carbide in nuclear applications.

  4. Low Cost Glass and Glass-Ceramic Substrates for Thin-Film Silicon Solar Cells: Final Subcontract Report, 25 January 2001

    Energy Technology Data Exchange (ETDEWEB)

    Ast, D.; Nemchuk, N.; Krasula, S.

    2002-07-01

    This report describes how Cornell University researchers developed several low-cost and simple barrier layers and tested their effectiveness both analytically (by SIMS) and by evaluating the electrical characteristics of devices fabricated on barrier-coated substrates. Devices fabricated included both majority-carrier devices (thin-film transistors) and minority-carrier devices (p-i-n junction diodes simulating solar cells) using various deposition techniques including the chemical vapor deposition of polysilicon from silane at low pressures (at Cornell University) and from dichlorosilane at atmospheric pressure (cooperation with Neudeck at Purdue University). The structure of the films deposited was investigated by using TEM and X-ray analysis. The performance of the minority- and majority-carrier devices fabricated on barrier-coated glass ceramic substrates was found to be identical to devices fabricated on control substrates of oxidized silicon and fused silica.

  5. The community-driven BiG CZ software system for integration and analysis of bio- and geoscience data in the critical zone

    Science.gov (United States)

    Aufdenkampe, A. K.; Mayorga, E.; Horsburgh, J. S.; Lehnert, K. A.; Zaslavsky, I.; Valentine, D. W., Jr.; Richard, S. M.; Cheetham, R.; Meyer, F.; Henry, C.; Berg-Cross, G.; Packman, A. I.; Aronson, E. L.

    2014-12-01

    Here we present the prototypes of a new scientific software system designed around the new Observations Data Model version 2.0 (ODM2, https://github.com/UCHIC/ODM2) to substantially enhance integration of biological and Geological (BiG) data for Critical Zone (CZ) science. The CZ science community takes as its charge the effort to integrate theory, models and data from the multitude of disciplines collectively studying processes on the Earth's surface. The central scientific challenge of the CZ science community is to develop a "grand unifying theory" of the critical zone through a theory-model-data fusion approach, for which the key missing need is a cyberinfrastructure for seamless 4D visual exploration of the integrated knowledge (data, model outputs and interpolations) from all the bio and geoscience disciplines relevant to critical zone structure and function, similar to today's ability to easily explore historical satellite imagery and photographs of the earth's surface using Google Earth. This project takes the first "BiG" steps toward answering that need. The overall goal of this project is to co-develop with the CZ science and broader community, including natural resource managers and stakeholders, a web-based integration and visualization environment for joint analysis of cross-scale bio and geoscience processes in the critical zone (BiG CZ), spanning experimental and observational designs. We will: (1) Engage the CZ and broader community to co-develop and deploy the BiG CZ software stack; (2) Develop the BiG CZ Portal web application for intuitive, high-performance map-based discovery, visualization, access and publication of data by scientists, resource managers, educators and the general public; (3) Develop the BiG CZ Toolbox to enable cyber-savvy CZ scientists to access BiG CZ Application Programming Interfaces (APIs); and (4) Develop the BiG CZ Central software stack to bridge data systems developed for multiple critical zone domains into a single

  6. Superdiffusion of Carbon by Vacancies Irradiated with Soft X-Rays in CZ Silicon / Superdifūzija Ar Vakancēm Iestarota Ar Mīkstajiem Rentgenstariem CZ Silīcijā

    Directory of Open Access Journals (Sweden)

    Janavičius A. J.

    2015-10-01

    Full Text Available Rezumējums: Rentgena staru fotoni, absorbēti Si atoma iekšējos slāņos, izstaro fotoelektronus un Ožē elektronus, ģenerējot vakances, starpmezglu silīcija atomus, vakanču un skābekļa kompleksus. Čohraļska silīcija kristāli, kas pārklāti ar oglekli 0.1 μm biezuma kārtā, tika apstaroti ar rentgena stariem, izmantojot krievu difraktometru DRON-3M. Oglekļa un skābekļa difūzija un koncentrāciju izmaiņa silīcijā tika izmērīta izmantojot infrasarkano staru FTIR spektroskopiju. Rentgena staru ģenerētās ļoti ātrās oglekļa difūzijas vai superdifūzijas koeficients istabas temperatūrā silīcijā ir simtiem tūkstošu reižu lielāks nekā termodifūzijas gadījumā.

  7. Large area lateral epitaxial overgrowth (LEO) of gallium nitride (GAN) thin films on silicon substrates and their characterization. Final report 1 March--30 September 99

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.F.; Linthicum, K.J.; Gehrke, T.; Thomson, D.; Ronning, C.

    1999-09-01

    Pendeo-epitaxial lateral growth (PE) of GaN epilayers on (0001) 6H-silicon carbide and (111) Si substrates has been achieved. Growth on the latter substrate was accomplished through the use of a 3C-SiC transition layer. The coalesced PE GaN epilayers were characterized using scanning electron diffraction, x-ray diffraction and photoluminescence spectroscopy. The regions of lateral growth exhibited {approximately} 0.2 deg crystallographic tilt relative to the seed layer. The GaN seed and PE epilayers grown on the 3C-SiC/Si substrates exhibited comparable optical characteristics to the GaN seed and PE grown on 6H- SiC substrates. The near band-edge emission of the GaN/3C-SiC/Si seed was 3.450 eV (FWHM approx. 19 meV) and the GaN/6H-SiC seed was 3.466 eV (FWHM approx. 4 meV).

  8. The effect of radiation damage on optical and scintillation properties of BGO crystals grown by the LTG Cz technique

    CERN Document Server

    Gusev, V A; Kupriyanov, I N; Kuznecov, G N; Shlegel, V N; Antsygin, V D; Vasiliev, Y V

    2002-01-01

    BGO crystals grown by the low-thermal-gradient Czochralski technique (LTG Cz) exhibit two distinct types of behavior upon radiation damage and recovery. The crystals termed as of L-type remain colorless after gamma-radiation doses as high as 10 Mrad. As the irradiation dose increases the scintillation light output shows a weak monotonous degradation to 15-25%, saturating at around several hundreds krad doses. The crystals termed as of N-type attain yellow coloration after irradiation. The light output drops abruptly for 35-50% as early as after 1 krad and does not change further on. The present work is devoted to the study of radiation damage effects, self-recovery, optically stimulated recovery and thermo-stimulated current in the L- and N-type BGO crystals produced by LTG Cz.

  9. Recent progress and patents in silicon nanotubes.

    Science.gov (United States)

    Pei, Li Z; Wang, Shang B; Fan, Chuan G

    2010-01-01

    Silicon nanotubes, as a novel kind of silicon nanomaterials, exhibit good application prospect in lithium ion battery, field effect transistors, magnetic nanodevices, hydrogen storage, nanoscale electron and field emitting devices. This article reviews the recent progress and patents in silicon nanotubes. The progress and corresponding patents for the synthesis of silicon nanotubes using different templates, hydrothermal method, electrochemical deposition, plasma method and laser ablation method are demonstrated. The experimental application and patents of silicon nanotubes as field effect transistors and lithium ion battery are discussed. The application potential of silicon nanotubes in magnetic devices, hydrogen storage, nanoscale electron and field-emitting devices is demonstrated. Finally, the future development of silicon nanotubes for the synthesis and practice application is also discussed.

  10. Liquid phase epitaxial growth of silicon on porous silicon for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Berger, S.; Quoizola, S.; Fave, A.; Kaminski, A.; Perichon, S.; Barbier, D.; Laugier, A. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France). Lab. de Physique de la Matiere; Ouldabbes, A.; Chabane-Sari, N.E. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France). Lab. de Physique de la Matiere; Lab. des Materiaux et Energies Renouvelables, Tlemcen (Algeria)

    2001-07-01

    The aim of this experiment is to grow a thin silicon layer (<50{mu}m) by liquid phase epitaxy (LPE) onto porous silicon. This one acts as a sacrificial layer in order to transfer the 50 {mu}m epitaxial layer onto foreign substrates like ceramics. After transfer, the silicon wafer is then re-usable. In this work, we used the following procedure : the porous silicon formation by HF anodisation on (100) or (111) Si wafers is realised in first step, followed by an eventual annealing in H{sub 2} atmosphere, and finally LPE silicon growth with different temperature profiles in order to obtain a silicon layer on the sacrificial porous silicon (p-Si). We observed a pyramidal growth on the surface of the (100) porous silicon but the coalescence was difficult to obtain. However, on a p-Si (111) oriented wafer, homogeneous layers were obtained. (orig.)

  11. Silicon entering through silicon utilizing organisms has biological effects in human beings

    Science.gov (United States)

    Shraddhamayananda, S.

    2012-12-01

    Except in the lungs, there is no evidence that silicon can do any harm in our body and Silicon is as essential as magnesium and calcium for us. It helps in proper activities of the bone tissues and all of the components in the human skeletal system. It can prevent osteoporosis in bones and also helps in lowering of blood pressure. Silicon can also inhibit fungal disease by physically inhibiting fungal germ tube penetration of the epidermis. Many of our foods which are associated with silicon utilizing organisms like rice, vegetables, wheat etc, contain plenty silicon, however, during processing most silicon get lost. In alternative medicine silicon is used to promote expulsion of foreign bodies from tissue, in formation of suppuration and finally expulsion of pus from abscesses. Silicon is also used to remove fibrotic lesions and scar tissue and in this way it can prevent formation of keloids. Sometimes it is also used to treat chronic otitis media, and chronic fistula,

  12. Marketingová analýza úspěšnosti projektu ZaNázory.cz

    OpenAIRE

    Pohan, Lukáš

    2012-01-01

    The bachelor thesis analyses the ZaNázory.cz project, its various parts and its success as well as its target audience. The analysis of the project is based on experience from the making of this project. Other field of interest of this thesis is to evaluate the success of this project in present and its future forecasts and compares the estimated target audience with real target audience at present.

  13. New, mechanically textured high-efficiency solar cells of low-cost silicon foil material. Final report; Neuartige, mechanisch texturierte Hochleistungssolarzellen aus kostenguenstigem Siliziumfolienmaterial. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bucher, E.; Fath, P.; Boueke, A.; Gerhards, C.; Huster, F.; Kuehn, R.; Hahn, G.; Terheiden, B.

    2001-07-01

    The project investigated the efficiency increase of solar cells made of multicrystalline silicon. Since 1992, Constance University has been working on a texturing process based on fast rotating profile tools. The technology is a low-cost grinding technology and will enhance the efficiency of multicrystalline Si solar cell processes in industrial applications. Combined with innovative cell concepts (semi-transparent POWER solar cells, rolling pressure metallization, innovative cell connection), the process has considerable technology transfer and marketing potential. The project intended a systematic improvement of the results achieved so far on the basis of new ideas and full exploitation of the available technological potential in the field of wafer, foil and thin film processes. [German] Zu Beginn des Vorhabens zeichnete sich weltweit der Trend ab, zunehmend multikristallines Silizium, blockgegossenes sowie foliengezogenes, in der Photovoltaik einzusetzen. Daraus ergab sich die Fragestellung der Steigerung des Solarzellenwirkungswirkungsgrades insbesondere auf diesen Materialien. Zwei wesentliche Aspekte sind dabei zu beruecksichtigen: eine effiziente Oberflaechentextur und eine angepasste Prozessoptimierung inklusive Volumenpasssivierung. Bei dem an der Universitaet Konstanz seit 1992 in der Laborentwicklung befindlichen Texturierungsverfahren auf Basis schnellrotierenden Profilwerkzeuge handelte es sich um eine vielseitig verwendbare Technologie, die zum einen als reines mechanisches Schleifverfahren kostenguenstig erscheint und zum anderen zu Wirkungsgradsteigerungen bei industrienahen multikristallinen Silizium-Solarzellenprozessen fuehrt. In Verbindung mit innovativen Zellkonzepten (semitransparente POWER-Solarzellen, Rolldruckmetallisierung, innovative Zellverschaltung) verfuegt dieses Verfahren ueber ein erhebliches Technologietransfer- und Marktpotential. Das vorliegende Vorhaben verfolgte eine systematische Verbesserung der bereits erzielten Ergebnisse

  14. Three-dimensional amorphous silicon solar cells on periodically ordered ZnO nanocolumns

    Czech Academy of Sciences Publication Activity Database

    Neykova, Neda; Moulin, E.; Campa, A.; Hruška, Karel; Poruba, Aleš; Stückelberger, M.; Haug, F.J.; Topič, M.; Ballif, C.; Vaněček, Milan

    2015-01-01

    Roč. 212, č. 8 (2015), s. 1823-1829 ISSN 1862-6300 R&D Projects: GA MŠk 7E12029; GA ČR(CZ) GA14-05053S EU Projects: European Commission(XE) 283501 - FAST TRACK Institutional support: RVO:68378271 Keywords : amorphous materials * hydrothermal growth * nanostructures * silicon * solar cells * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.648, year: 2015

  15. Synthesis of carbon fibre-reinforced, silicon carbide composites by ...

    Indian Academy of Sciences (India)

    pyrolysis (PIP), liquid silicon infiltration (LSI), sol–gel, reaction hot-pressing, have been used for ... resin matrix and is then infiltrated with molten silicon (Krenkel 2001); but the presence of free silicon may act as a ... and (iv) finally carbothermal reduction of oxides to carbides/borides at 1873 and 1973 K for 3 h as shown by ...

  16. Budování značek Google a Seznam.cz na českém trhu: komparativní studie

    OpenAIRE

    Bešťák, Václav

    2016-01-01

    For many years, the Czech Republic was one of the six countries (including Russia, Japan, Taiwan, China, and Korea), where Google was not the number one search engine. Google increased its market share in the year 2011, in comparison with the local leader Seznam.cz. Nevertheless, the Czech market stays still highly specific and both companies are still competing and striving for the first position. Bachelor thesis "Brand building of Google and Seznam.cz on the Czech market: comparative study"...

  17. Lithographically patterned silicon nanostructures on silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Megouda, Nacera [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Universite Lille1, Parc de la Haute Borne, 50 Avenue de Halley-BP 70478, 59658 Villeneuve d' Ascq and Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, CNRS-8520), Cite Scientifique, Avenue Poincare-B.P. 60069, 59652 Villeneuve d' Ascq (France); Faculte des Sciences, Universite Mouloud Mammeri, Tizi-Ouzou (Algeria); Unite de Developpement de la Technologie du Silicium (UDTS), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 merveilles, Alger (Algeria); Piret, Gaeelle; Galopin, Elisabeth; Coffinier, Yannick [Institut de Recherche Interdisciplinaire (IRI, USR 3078), Universite Lille1, Parc de la Haute Borne, 50 Avenue de Halley-BP 70478, 59658 Villeneuve d' Ascq and Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, CNRS-8520), Cite Scientifique, Avenue Poincare-B.P. 60069, 59652 Villeneuve d' Ascq (France); Hadjersi, Toufik, E-mail: hadjersi@yahoo.com [Unite de Developpement de la Technologie du Silicium (UDTS), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 merveilles, Alger (Algeria); Elkechai, Omar [Faculte des Sciences, Universite Mouloud Mammeri, Tizi-Ouzou (Algeria); and others

    2012-06-01

    The paper reports on controlled formation of silicon nanostructures patterns by the combination of optical lithography and metal-assisted chemical dissolution of crystalline silicon. First, a 20 nm-thick gold film was deposited onto hydrogen-terminated silicon substrate by thermal evaporation. Gold patterns (50 {mu}m Multiplication-Sign 50 {mu}m spaced by 20 {mu}m) were transferred onto the silicon wafer by means of photolithography. The etching process of crystalline silicon in HF/AgNO{sub 3} aqueous solution was studied as a function of the silicon resistivity, etching time and temperature. Controlled formation of silicon nanowire arrays in the unprotected areas was demonstrated for highly resistive silicon substrate, while silicon etching was observed on both gold protected and unprotected areas for moderately doped silicon. The resulting layers were characterized using scanning electron microscopy (SEM).

  18. Vliv zavedení placeného obsahu na zpravodajský server IHNED.cz

    OpenAIRE

    Janíková, Simona

    2017-01-01

    This diploma thesis summarises the development of paid content of ihned.cz, on-line news server of the Czech economic daily Hospodářské noviny. It observes the influence of paywall from August 2014 until April 2015. The aim of the implementation of paywall was to show that the content created on the server was valuable. The theoretical part deals with new challenges media face, including economic and technological changes; it describes the rise of commercialization and media reaction, and sol...

  19. Effect of the packing structure of silicon chunks on the melting process and carbon reduction in Czochralski silicon crystal growth

    Science.gov (United States)

    Liu, Xin; Nakano, Satoshi; Kakimoto, Koichi

    2017-06-01

    Carbon (C) contamination in Czochralski silicon (CZ-Si) crystal growth mainly originates from carbon monoxide (CO) generation on the graphite components, which reaches a maximum during the melting stage. Loading a crucible with poly-Si feedstock includes many technical details for optimization of the melting and growth processes. To investigate the effect of the packing structure of Si chunks on C accumulation in CZ-Si crystal growth, transient global simulations of heat and mass transport were performed for the melting process with different packing structures of poly-Si. The heat transport modeling took into account the effective thermal conductivity (ETC) of the Si feedstock, which is affected by the packing structure. The effect of the chunk size on the melting process and C accumulation were investigated by parametric studies of different packing structures. The heat transport and melting process in the crucible were affected by the ETC and the emissivity of the Si feedstock. It was found that smaller Si chunks packed in the upper part could speed up the melting process and smooth the power profile. Decreasing the duration of the melting process is favorable for reduction of C contamination in the Si feedstock. Parametric studies indicated that optimization of the melting process by the packing structure is possible and essential for C reduction in CZ-Si crystal growth.

  20. Responses of unsaturated Pseudomonas putida CZ1 biofilms to environmental stresses in relation to the EPS composition and surface morphology.

    Science.gov (United States)

    Lin, Huirong; Chen, Guangcun; Long, Dongyan; Chen, Xincai

    2014-12-01

    The extracellular polymeric substance (EPS) and surface properties of unsaturated biofilms of a heavy metal-resistant rhizobacterium Pseudomonas putida CZ1, in response to aging, pH, temperature and osmotic stress, were studied by quantitative analysis of EPS and atomic force microscope. It was found that EPS production increased approximately linearly with culture time, cells in the air-biofilm interface enhanced EPS production and decreased cell volume to cope with nutrient depletion during aging. Low pH, high temperature and certain osmotic stress (120 mM NaCl) distinctly stimulated EPS production, and the main component enhanced was extracellular protein. In addition to the enhancement of EPS production in response to high osmotic (328 mM NaCl) stress, cells in the biofilm adhere tightly together to maintain a particular microenvironment. These results indicated the variation of EPS composition and the cooperation of cells in the biofilms is important for the survival of Pseudomonas putida CZ1 from environmental stresses in the unsaturated environments such as rhizosphere.

  1. Delimitation of Areas of Environmental Conflicts on the Background of Geological Conditions, Exemplified by Stary Sącz Commune

    Directory of Open Access Journals (Sweden)

    Gałaś Slávka

    2014-12-01

    Full Text Available Delimitation and characterization of areas of conflict are essential to assess suitability of land for different activities carried out in the field of rational land use. In the paper, delimitation of the conflict areas and conflicts categorization in terms of possibility of their overcoming, the scale of the range and the period of their occurrence exemplified by urban - rural commune Stary Sącz have been presented. The software ArcGIS 10.1, the method of maps superimposing and analysis of interactions between different geoenvironmental factors have been applied to obtain the goal of the investigation. Specific geological structure together with morphological and climatic conditions in Stary Sącz commune create ideal conditions for occurrence of con-flict areas on the background of the geological conditions. Accurate and early recognition of these conflicts - existing and potential ones, is a prerequisite for the environmental risk prevention and elimination of its effects through the proper preparation of planning documents and development plans and programs.

  2. A DLTS study of hydrogen doped czochralski-grown silicon

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, M. [Infineon Technologies Austria AG, 9500 Villach (Austria); Laven, J.G. [Infineon Technologies AG, 81726 Munich (Germany); Kirnstoetter, S. [Institute of Solid State Physics, Graz University of Technology, 8010 Graz (Austria); Schustereder, W. [Infineon Technologies Austria AG, 9500 Villach (Austria); Schulze, H.-J. [Infineon Technologies AG, 81726 Munich (Germany); Rommel, M. [Fraunhofer Institute of Integrated Systems and Devices IISB, 91058 Erlangen (Germany); Frey, L. [Fraunhofer Institute of Integrated Systems and Devices IISB, 91058 Erlangen (Germany); Chair of Electron Devices, FAU Erlangen-Nuremberg, 91058 Erlangen (Germany)

    2015-12-15

    In this study we examine proton implanted and subsequently annealed commercially available CZ wafers with the DLTS method. Depth-resolved spreading resistance measurements are shown, indicating an additional peak in the induced doping profile, not seen in the impurity-lean FZ reference samples. The additional peak lies about 10–15 μm deeper than the main peak near the projected range of the protons. A DLTS characterization in the depth of the additional peak indicates that it is most likely not caused by classical hydrogen-related donors known also from FZ silicon but by an additional donor complex whose formation is assisted by the presence of silicon self-interstitials.

  3. Search for WW and WZ production in lepton, neutrino plus jets final states at CDF Run II and Silicon module production and detector control system for the ATLAS SemiConductor Tracker

    Energy Technology Data Exchange (ETDEWEB)

    Sfyrla, Anna [Univ. of Geneva (Switzerland)

    2008-03-10

    In the first part of this work, we present a search for WW and WZ production in charged lepton, neutrino plus jets final states produced in p$\\bar{p}$ collisions with √s = 1.96 TeV at the Fermilab Tevatron, using 1.2 fb-1 of data accumulated with the CDF II detector. This channel is yet to be observed in hadron colliders due to the large singleWplus jets background. However, this decay mode has a much larger branching fraction than the cleaner fully leptonic mode making it more sensitive to anomalous triple gauge couplings that manifest themselves at higher transverse W momentum. Because the final state is topologically similar to associated production of a Higgs boson with a W, the techniques developed in this analysis are also applicable in that search. An Artificial Neural Network has been used for the event selection optimization. The theoretical prediction for the cross section is σWW/WZtheory x Br(W → ℓv; W/Z → jj) = 2.09 ± 0.14 pb. They measured NSignal = 410 ± 212(stat) ± 102(sys) signal events that correspond to a cross section σWW/WZ x Br(W → ℓv; W/Z → jj) = 1.47 ± 0.77(stat) ± 0.38(sys) pb. The 95% CL upper limit to the cross section is estimated to be σ x Br(W → ℓv; W/Z → jj) < 2.88 pb. The second part of the present work is technical and concerns the ATLAS SemiConductor Tracker (SCT) assembly phase. Although technical, the work in the SCT assembly phase is of prime importance for the good performance of the detector during data taking. The production at the University of Geneva of approximately one third of the silicon microstrip end-cap modules is presented. This collaborative effort of the university of Geneva group that lasted two years, resulted in 655 produced modules, 97% of which were good modules, constructed within the mechanical and electrical specifications and delivered in the SCT collaboration for assembly on the end-cap disks. The SCT end-caps and barrels

  4. The LHCb silicon tracker project

    CERN Document Server

    Blouw, J

    2004-01-01

    Two silicon strip detectors, the Trigger Tracker(TT) and the Inner Tracker(IT) will be constructed for the LHCb experiment. Transverse momentum information extracted from the TT will be used in the Level 1 trigger. The IT is part of the main tracking system behind the magnet. Both silicon detectors will be read out using a custom-developed chip by the ASIC lab in Heidelberg. The signal-over-noise behavior and performance of various geometrical designs of the silicon sensors, in conjunction with the Beetle read-out chip, have been extensively studied in test beam experiments. Results from those experiments are presented, and have been used in the final choice of sensor geometry.

  5. Silicon Photonics-Silicon Raman Lasers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 10. Silicon Photonics - Silicon Raman Lasers. P K Basu. General Article Volume 12 ... Keywords. Silicon photonics; Si Raman laser; semiconductor laser; light emitter; optical interconnect; optical communication; Indirect gap semiconductors.

  6. Wybrane farmakokinetyczne interakcje leków w trakcie leczenia padaczki. Część II

    Directory of Open Access Journals (Sweden)

    Karol Jastrzębski

    2013-04-01

    Full Text Available Padaczka to choroba o nieznanej do końca etiologii, charakteryzująca się występowaniem nieprowokowanych napadów padaczkowych. Napad padaczkowy to z kolei przejściowa zmiana reaktywności lub zmiana stanu fizjologicznego części bądź całego mózgu. Napady dzielą się na: częściowe, uogólnione i niesklasyfikowane. Pojęcie padaczki lekoopornej może się wydawać oczywiste i zrozumiałe, niemniej jednak nie opracowano dotychczas powszechnie uznawanej szczegółowej definicji. W efekcie lekarze i badacze stosują bardzo różne kryteria, a w niektó- rych przypadkach nawet rezygnują z dokładnych kryteriów, co znacznie utrudnia porównywanie wyników badań klinicznych i tworzenie wytycznych. W leczeniu padaczki nie występuje jeden standardowy sposób postępowania. Celem terapii padaczki jest całkowita kontrola napadów i uzyskanie jak najmniejszych objawów niepożądanych podczas leczenia lekami przeciwpadaczkowymi. Lek powinien być dostosowany do typu napadu lub zespołu padaczkowego, częstości i ciężkości napadów. Wybór leków zależy od rodzaju napadów, przykładowo w napadach pierwotnych uogólnionych stosowany jest kwas walproinowy, natomiast we wtórnie uogólnionych i częściowych – karbamazepina. Leki starszej generacji (fenytoina, fenobarbital, prymidon powoli wychodzą z użycia. Mogą być jednak przepisywane z powodu indywidualnych wskazań. Jest też bardzo duża grupa nowych leków (lamotrygina, wigabatryna, okskarbazepina, gabapentyna, lewetyracetam, felbamat, topiramat, tiagabina, które stają się coraz bardziej popularne. Pojawienie się leków nowej generacji dało im pewną przewagę w stosunku do starszych leków. Cechują je: większa swoistość działania, lepsze właściwości farmakokinetyczne, lepsza ocena klinicznych prób i słabsze objawy niepożądane. Z badań klinicznych i z bezpośrednich obserwacji wynika, iż są to leki bardzo przydatne w niektórych typach padaczek. Nie ulega w

  7. Next generation structural silicone glazing

    Directory of Open Access Journals (Sweden)

    Charles D. Clift

    2015-06-01

    Full Text Available This paper presents an advanced engineering evaluation, using nonlinear analysis of hyper elastic material that provides significant improvement to structural silicone glazing (SSG design in high performance curtain wall systems. Very high cladding wind pressures required in hurricane zones often result in bulky SSG profile dimensions. Architectural desire for aesthetically slender curtain wall framing sight-lines in combination with a desire to reduce aluminium usage led to optimization of silicone material geometry for better stress distribution.To accomplish accurate simulation of predicted behaviour under structural load, robust stress-strain curves of the silicone material are essential. The silicone manufacturer provided physical property testing via a specialized laboratory protocol. A series of rigorous curve fit techniques were then made to closely model test data in the finite element computer analysis that accounts for nonlinear strain of hyper elastic silicone.Comparison of this advanced design technique to traditional SSG design highlights differences in stress distribution contours in the silicone material. Simplified structural engineering per the traditional SSG design method does not provide accurate forecasting of material and stress optimization as shown in the advanced design.Full-scale specimens subject to structural load testing were performed to verify the design capacity, not only for high wind pressure values, but also for debris impact per ASTM E1886 and ASTM E1996. Also, construction of the test specimens allowed development of SSG installation techniques necessitated by the unique geometry of the silicone profile. Finally, correlation of physical test results with theoretical simulations is made, so evaluation of design confidence is possible. This design technique will introduce significant engineering advancement to the curtain wall industry.

  8. Typology of the Author's Status: Two Experiences – Cz. Miłosz and G. von Rezzori

    Directory of Open Access Journals (Sweden)

    Tetiana Basniak

    2013-12-01

    Full Text Available A number of typological coincidences in the texts of the Polish-American writer Cz. Miłosz, a Nobel prize winner and German classic G. Von Rezzori are considered. The work of these authors is a result of the crisis of the twentieth century, tragic decline of the traditional culture that was associated with the status of a writer in exile. Biographical background appears very organic for their texts , and in this case it almost coincides: the parents of both future artists “temporarily” left their land when the the situation in the empires was not stable – the Austria-Hungarian (in the case of Rezzori and Russian ( in the case of Miłosz. Both writers lived in exile. In their opinion, topos of childhood tragically detached from the future life events, generated separate thematic and anthropological link in their creative work . In this sense “The Issa Valley” (“Dolina Issy” 1955 by Cz. Miłosz and “The Snows Of Yesteryear” (“Blumen im Schnee” 1989 by Rezzori are the most exemplary. The works of a number of other representatives of the European literature of the twentieth century (e.g., “Others shores” by V. Nabokov . The problem discussed is still relevant. Tendence to autobiographism as genre sign of their texts, and, in addition, the source of many images – primarily children and adolescent characters is evident. The most obvious typological parallels emerge in several dimensions: the perspective of ideological clichés (negation Nietzschean ideas of nihilism by each writer, specific system of images (including images of nannies Cassandra and Antonina, relection the typical paradigm , which presents a complete image of “the world of childhood”, besides – in relation to the issue of “language as poetic phenomenon” (Miłosz’s definition, that mirrors the multinational palette the lost homeland.

  9. Silicon nanostructures for cancer diagnosis and therapy.

    Science.gov (United States)

    Peng, Fei; Cao, Zhaohui; Ji, Xiaoyuan; Chu, Binbin; Su, Yuanyuan; He, Yao

    2015-01-01

    The emergence of nanotechnology suggests new and exciting opportunities for early diagnosis and therapy of cancer. During the recent years, silicon-based nanomaterials featuring unique properties have received great attention, showing high promise for myriad biological and biomedical applications. In this review, we will particularly summarize latest representative achievements on the development of silicon nanostructures as a powerful platform for cancer early diagnosis and therapy. First, we introduce the silicon nanomaterial-based biosensors for detecting cancer markers (e.g., proteins, tumor-suppressor genes and telomerase activity, among others) with high sensitivity and selectivity under molecular level. Then, we summarize in vitro and in vivo applications of silicon nanostructures as efficient nanoagents for cancer therapy. Finally, we discuss the future perspective of silicon nanostructures for cancer diagnosis and therapy.

  10. Intrinsic Gettering in Nitrogen-Doped and Hydrogen-Annealed Czochralski-Grown Silicon Wafers

    Science.gov (United States)

    Goto, Hiroyuki; Pan, Lian-Sheng; Tanaka, Masafumi; Kashima, Kazuhiko

    2001-06-01

    The properties of nitrogen-doped and hydrogen-annealed Czochralski-grown silicon (NHA-CZ-Si) wafers were investigated in this study. The quality of the subsurface was investigated by monitoring the generation lifetime of minority carriers, as measured by the capacitance-time measurements of a metal oxide silicon capacitor (MOS C-t). The intrinsic gettering (IG) ability was investigated by determining the nickel concentration on the surface and in the subsurface as measured by graphite furnace atomic absorption spectrometry (GFAAS) after the wafer was deliberately contaminated with nickel. From the results obtained, the generation lifetimes of these NHA-CZ-Si wafers were determined to be almost the same as, or a little longer than those of epitaxial wafers, and the IG ability was proportional to the total volume of oxygen precipitates [i.e., bulk micro defects (BMDs)], which was influenced by the oxygen and nitrogen concentrations in the wafers. Therefore, it is suggested that the subsurface of the NHA-CZ-Si wafers is of good quality and the IG capacity is controllable by the nitrogen and oxygen concentrations in the wafers.

  11. Characterization of the loss of the dislocation-free growth during Czochralski silicon pulling

    Science.gov (United States)

    Lanterne, Adeline; Gaspar, Guilherme; Hu, Yu; Øvrelid, Eivind; Di Sabatino, Marisa

    2017-01-01

    The loss of the dislocation-free growth (structure loss) during Czochralski (Cz) silicon pulling can have a strong negative impact on the production yield of the Cz photovoltaic industry. As almost no publication has been dedicated to this phenomenon in the past, this paper aims at investigate in detail the loss of the dislocation-free growth and its origin by characterizing an industrial-scale n-type Cz silicon ingot exhibiting such issue. After the occurrence of a perturbation, generation and propagation of slip dislocations in the already grown crystal have been observed. These dislocations, generated over the whole ingot cross-section, propagate with the solidification front during further growth. Additional small perturbations seem then to be responsible for their multiplication together with the transition to a multicrystalline structure. Investigations were conducted to find the perturbation causing the structure loss in the ingot. A pinhole, small gas bubble of 0.5 mm diameter, was identified as the main cause for the generation of dislocations.

  12. Silicone chain extender

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a silicone chain extender, more particularly a chain extender for silicone polymers and copolymers, to a chain extended silicone polymer or copolymer and to a functionalized chain extended silicone polymer or copolymer, to a method for the preparation thereof...

  13. New Perspectives in Silicon Micro and Nanophotonics

    Science.gov (United States)

    Casalino, M.; Coppola, G.; De Stefano, L.; Calio, A.; Rea, I.; Mocella, V.; Dardano, P.; Romano, S.; Rao, S.; Rendina, I.

    2015-05-01

    In the last two decades, there has been growing interest in silicon-based photonic devices for many optical applications: telecommunications, interconnects and biosensors. In this work, an advance overview of our results in this field is presented. Proposed devices allow overcoming silicon intrinsic drawbacks limiting its application as a photonic substrate. Taking advantages of both non-linear and linear effects, size reduction at nanometric scale and new two-dimensional emerging materials, we have obtained a progressive increase in device performance along the last years. In this work we show that a suitable design of a thin photonic crystal slab realized in silicon nitride can exhibit a very strong field enhancement. This result is very promising for all photonic silicon devices based on nonlinear phenomena. Moreover we report on the fabrication and characterization of silicon photodetectors working at near-infrared wavelengths based on the internal photoemission absorption in a Schottky junction. We show as an increase in device performance can be obtained by coupling light into both micro-resonant cavity and waveguiding structures. In addition, replacing metal with graphene in a Schottky junction, a further improve in PD performance can be achieved. Finally, silicon-based microarray for biomedical applications, are reported. Microarray of porous silicon Bragg reflectors on a crystalline silicon substrate have been realized using a technological process based on standard photolithography and electrochemical anodization of the silicon. Our insights show that silicon is a promising platform for the integration of various optical functionalities on the same chip opening new frontiers in the field of low-cost silicon micro and nanophotonics.

  14. The Silicon Lattice Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J

    2003-11-24

    Previously, the generalized luminosity L was defined and calculated for all incident channels based on an NLC e{sup +}e{sup -} design. Alternatives were then considered to improve the differing beam-beam effects in the e{sup -}e{sup -}, e{gamma} and {gamma}{gamma} channels. One example was tensor beams composed of bunchlets n{sub ijk} implemented with a laser-driven, silicon accelerator based on micromachining techniques. Problems were considered and expressions given for radiative broadening due to bunchlet manipulation near the final focus to optimize luminosity via charge enhancement, neutralization or bunch shaping. Because the results were promising, we explore fully integrated structures that include sources, optics (for both light and particles) and acceleration in a common format--an accelerator-on-chip. Acceptable materials (and wavelengths) must allow velocity synchronism between many laser and electron pulses with optimal efficiency in high radiation environments. There are obvious control and cost advantages that accrue from using silicon structures if radiation effects can be made acceptable and the structures fabricated. Tests related to deep etching, fabrication and radiation effects on candidate amorphous and crystalline materials indicate Si(1.2 < {lambda}{sub L} < 10 {micro}m) and fused c-SiO{sub 2}(0.3 < {lambda}{sub L} < 4 {micro}m) to be ideal.

  15. Rotational Period Determination of Two Mars-crossing, a Main Belt Asteroid and a PHA: (14309) Defoy, (56116) 1999 CZ7, (5813) Eizaburo and (3122) Florence.

    Science.gov (United States)

    Tomassini, Angelo; Scardella, Maurizio; Franceschini, Francesco; Pierri, Fernando

    2018-01-01

    The main-belt asteroids (5813) Eizaburo and two Mars crossing minor bodies, (14309) Defoy and (56116) 1999 CZ7, have been observed over several nights throughout 2017 March-September in order to determine their synodic rotational period. We also took the opportunity of the (3122) Florence close passage with the Earth in September-October to find its lightcurve.

  16. Optoelectronic Device Integration in Silicon (OpSIS)

    Science.gov (United States)

    2015-10-26

    AFRL-AFOSR-VA-TR-2016-0066 OPTOELECTRONIC DEVICE INTEGRATION IN SILICON Xiaodong Xu UNIVERSITY OF WASHINGTON Final Report 10/26/2015 DISTRIBUTION A... Optoelectronic Device Integration in Silicon 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-10-1-0439 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr...Delaware in the development of fundamental design tools and methodologies for optoelectronic devices in silicon photonics. We proposed to develop

  17. Evaluation of selected chemical processes for production of low-cost silocon. (Phases I and II. ) Final report, October 9, 1975--July 9, 1978. Silicon Material Task, Low-Cost Solar Array Project

    Energy Technology Data Exchange (ETDEWEB)

    Blocher, J.M. Jr.; Browning, M.F.

    1978-07-09

    The zinc reduction of silicon tetrachloride in a fluidized bed of seed particles to yield a granular product was studied along with several modifications of the thermal decomposition or hydrogen reduction of silicon tetraiodide. Although all contenders were believed to be capable of meeting the quality requirements of the LSA Project, it was concluded that only the zinc reduction of the chloride could be made economically feasible at a cost below $10/kg silicon (1975 dollars). Accordingly, subsequent effort was limited to evaluating that process. A miniplant, consisting of a 5-cm-diameter fluidized-bed reactor and associated equipment was used to study the deposition parameters, temperature, reactant composition, seed particle size, bed depth, reactant throughput, and methods of reactant introduction. It was confirmed that the permissible range of fluidized-bed temperature was limited at the lower end by zinc condensation (918 C) and at higher temperatures by rapidly decreasing conversion efficiency (by 0.1 percent per degree C from 72 percent (thermodynamic) at 927 for a stoichiometric mixture). Use of a graded bed temperature was shown to increase the conversion efficiency over that obtained in an isothermal bed. Other aspects of the process such as the condensation and fused-salt electrolysis of the ZnCl/sub 2/ by-product for recycle of zinc and chlorine were studied to provide information required for design of a 50 MT/year experimental facility, visualized as the next stage in the development. Projected silicon costs of $7.35 and $8.71 per kg (1975 dollars) for a 1000 MT/year facilitywere obtained, depending upon the number and size of the fluidized-bed reactors and ZnCl/sub 2/ electrolytic cells used. An energy payback time of 5.9 months was calculated for the product silicon.

  18. Silicon takes a spin

    NARCIS (Netherlands)

    Jansen, R.

    An efficient way to transport electron spins from a ferromagnet into silicon essentially makes silicon magnetic, and provides an exciting step towards integration of magnetism and mainstream semiconductor electronics.

  19. Photovoltaic Small Molecules of TPA(FxBT-T-Cz)3: Tuning Open-Circuit Voltage over 1.0 V for Their Organic Solar Cells by Increasing Fluorine Substitution.

    Science.gov (United States)

    Wang, Qiong; Duan, Linrui; Tao, Qiang; Peng, Wenhong; Chen, Jianhua; Tan, Hua; Yang, Renqiang; Zhu, Weiguo

    2016-11-09

    To simultaneously improve both open-circuit voltage (Voc) and short-circuit current density (Jsc) for organic solar cells, a novel D(A-π-Ar)3 type of photovoltaic small molecules of TPA(FxBT-T-3Cz)3 was designed and synthesized, which contain central triphenylamine (TPA), terminal carbazole (Cz), armed fluorine-substituted benzothiadiazole (FxBT, where x = 1 or 2), and bridged thiophene (T) units. A narrowed ultraviolet-visible absorption and a decreasing highest occupied molecular orbital energy level were observed from TPA(F1BT-T-3Cz)3 to TPA(F2BT-T-3Cz)3 with increasing fluorine substitution. However, the TPA(F2BT-T-3Cz)3/PC71BM-based solar devices showed a rising Voc of 1.01 V and an enhanced Jsc of 10.84 mA cm(-2) as well as a comparable power conversion efficiency of 4.81% in comparison to the TPA(F1BT-T-3Cz)3/PC71BM-based devices. Furthermore, in comparison to the parent TPA(BT-T-3Cz)3 molecule without fluorine substitution, the fluorine-substituted TPA(FxBT-T-3Cz)3 molecules exhibited significantly incremental Voc and Jsc values in their bulk heterojunction organic solar cells, owing to fluorine incorporation in the electron-deficient benzothiadiazole unit.

  20. Porous silicon nanocrystals in a silica aerogel matrix

    Science.gov (United States)

    2012-01-01

    Silicon nanoparticles of three types (oxide-terminated silicon nanospheres, micron-sized hydrogen-terminated porous silicon grains and micron-size oxide-terminated porous silicon grains) were incorporated into silica aerogels at the gel preparation stage. Samples with a wide range of concentrations were prepared, resulting in aerogels that were translucent (but weakly coloured) through to completely opaque for visible light over sample thicknesses of several millimetres. The photoluminescence of these composite materials and of silica aerogel without silicon inclusions was studied in vacuum and in the presence of molecular oxygen in order to determine whether there is any evidence for non-radiative energy transfer from the silicon triplet exciton state to molecular oxygen adsorbed at the silicon surface. No sensitivity to oxygen was observed from the nanoparticles which had partially H-terminated surfaces before incorporation, and so we conclude that the silicon surface has become substantially oxidised. Finally, the FTIR and Raman scattering spectra of the composites were studied in order to establish the presence of crystalline silicon; by taking the ratio of intensities of the silicon and aerogel Raman bands, we were able to obtain a quantitative measure of the silicon nanoparticle concentration independent of the degree of optical attenuation. PMID:22805684

  1. c.z. Roux

    African Journals Online (AJOL)

    of the possible output versus input relationships which remain invariant with time. Hence, it follows that in. (15) uI (t) can be interpreted as a growth law and u4 (t) can be interpreted as the main control law. If the second moment matrixC isof rank one and Ipl

  2. c.z. Roux

    African Journals Online (AJOL)

    series description can be transcribed to an optimal linear discrete time feedback control system. The origin of the present approach lies in the discovery. (Roux, 1974) that In (body mass) and In (cumulative feed intake) are linearly related and that cumulative feed intake, like body mass, can be described over time.

  3. Producing Silicon Carbide/Silicon Nitride Fibers

    Science.gov (United States)

    1986-01-01

    Manufacturing process makes CxSiyNz fibers. Precursor fibers spun from extruding machine charged with polycarbosilazane resin. When pyrolyzed, resin converted to cross-linked mixture of silicon carbide and silicon nitride, still in fiber form. CxSiyNz fibers promising substitutes for carbon fibers in high-strength, low-weight composites where high electrical conductivity unwanted.

  4. Czochralski silicon crystal growth: Modeling and simulation study

    Science.gov (United States)

    Javidi, Massoud

    Czochralski (CZ) crystal growth process is a widely used technique in the manufacturing of silicon crystals and other semiconductor materials such as germanium (Ge) and gallium arsenide (GaAs). The ultimate goal for the Integrated Circuit (IC) industry is to have the highest quality substrate. There is a huge interest to manipulate the thermal field in both the melt and crystal and control the melt convection and crystal-annealing rate in order to reduce growth striations, impurity and dopant inhomogeneity concentrations, excess point defects generation at interface, and micro defects nucleation and growth within the growing crystal. The objective of this investigation has been to facilitate and spearhead the development of a simple/efficient simulation tool for the accurate prediction of global thermal and flow fields and the melt-crystal interface position in the CZ process. The numerical algorithm employs a rectangular (fixed or non-uniform) mesh for enhanced computational efficiency and an enthalpy-based technique for interface tracking. Turbulent flow in the melt is accounted for by utilizing a K-ε model. Radiative heat transfer is modeled in a lumped parameter sense without appreciably compromising on solution accuracy to further allow for CPU times savings. The simulation tool is validated in a number of benchmark flows such as Wheeler's problem. For the CZ crystal growth process, an entire growth cycle has been computed and reliable predictions for the evolution of interface position, and flow/thermal field characteristics have been obtained. The enhanced CPU efficiency of the approach developed here could help integrate it into on-line control strategies.

  5. Silicon: electrochemistry and luminescence

    NARCIS (Netherlands)

    Kooij, Ernst Stefan

    1997-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible

  6. Silicon photonics beyond silicon-on-insulator

    Science.gov (United States)

    Chiles, Jeff; Fathpour, Sasan

    2017-05-01

    The standard platform for silicon photonics has been ridge or channel waveguides fabricated on silicon-on-insulator (SOI) wafers. SOI waveguides are so versatile and the technology built around it is so mature and popular that silicon photonics is almost regarded as synonymous with SOI photonics. However, due to several shortcomings of SOI photonics, novel platforms have been recently emerging. The shortcomings could be categorized into two sets: (a) those due to using silicon as the waveguide core material; and (b) those due to using silicon dioxide as the bottom cladding layer. Several heterogeneous platforms have been developed to address the first set of shortcomings. In such important heterogeneous integrated photonic platforms, the top silicon layer of SOI is typically replaced by a thin film of another optical material with a refractive index higher than the buried oxide (BOX) bottom cladding layer. Silicon is still usually preferred as the substrate of choice, but silicon has no optical functionality. In contrast, the second category of solutions aim at using silicon as the core waveguide material, while resolving issues related to the BOX layer. Particularly, one of the main drawbacks of SOI is that the BOX layer induces high optical loss in the mid-wavelength infrared (mid-IR) range. Accordingly, a host of platforms have been proposed, and some have been demonstrated, in which the BOX is replaced with insulating materials that have low intrinsic loss in the mid-IR. Examples are sapphire, lithium niobate, silicon nitride and air (suspended Si membrane waveguides). Although silicon is still the preferred substrate, sometimes a thin film of silicon, on which the optical waveguide is formed, is directly placed on top of another substrate (e.g., sapphire or lithium niobate). These alternative substrates act as both mechanical support and the lower cladding layer. In addition to the demands of mid-IR photonics, the non-SOI platforms can potentially offer other

  7. The chemistry of silicon

    CERN Document Server

    Rochow, E G; Emeléus, H J; Nyholm, Ronald

    1975-01-01

    Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

  8. Porous silicon gettering

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Menna, P.; Al-Jassim, M. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-08-01

    We have studied a novel extrinsic gettering method that utilizes the very large surface areas, produced by porous silicon etch on both front and back surfaces of the silicon wafer, as gettering sites. In this method, a simple and low-cost chemical etching is used to generate the porous silicon layers. Then, a high-flux solar furnace (HFSF) is used to provide high-temperature annealing and the required injection of silicon interstitials. The gettering sites, along with the gettered impurities, can be easily removed at the end the process. The porous silicon removal process consists of oxidizing the porous silicon near the end the gettering process followed by sample immersion in HF acid. Each porous silicon gettering process removes up to about 10 {mu}m of wafer thickness. This gettering process can be repeated so that the desired purity level is obtained.

  9. First-principles study of new series of quaternary Heusler alloys CsSrCZ (Z=Si, Ge, Sn, P, As, and Sb)

    Energy Technology Data Exchange (ETDEWEB)

    Bouabça, A. [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria); Rozale, H., E-mail: hrozale@yahoo.fr [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria); Amar, A. [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria); Wang, X.T. [School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 400044 (China); Sayade, A. [UCCS, CNRS-UMR 8181, Université d’Artois, Faculté des Sciences Jean Perrin, Rue Jean Souvraz, SP 18, 62307 Lens Cedex (France); Chahed, A. [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria)

    2016-12-01

    The structural, electronic, magnetic, and thermal properties of new quaternary Heusler alloys CsSrCZ (Z=Si, Ge, Sn, P, As, and Sb) were investigated using the full-potential linearized augmented plane wave (FPLAPW) within the generalized gradient approximation (GGA) and GGA plus modified Becke and Johnson as the exchange correlation. The results showed that all Heusler compounds were stable in Type (I) structure. The CsSrCZ (Z=Si, Ge, Sn) compounds had a nearly HM characteristic, and CsSrCZ (Z=P, As, Sb) compounds were true half-metallic (HM) ferromagnets. The strong spin polarization of p orbital for C, Si, Ge, Sn, P, As, and Sb atoms is found to be the origin of ferromagnetic. The half-metallicity is preserved up to a lattice contraction of 3.45%, 1.69%, 1.69%, 7.16%, 7.16%, and 11.2% for all six quaternary Heusler compounds. We also investigated the thermal effects using the quasi-harmonic Debye model. - Highlights: • Electronic, magnetic, and thermodynamic properties of CsSrCZ (Z=Si, Ge, Sn, P, As, and Sb) are investigated. • Until now, there have been no reports theoretical and experimental studies on d{sup 0} half-metals with quaternary structures. • The strong spin polarization of p orbital for C, Si, Ge, Sn, P, As, and Sb atoms is found to be the origin of ferromagnetic. • The half-metallicity is preserved up to a lattice contraction.

  10. Automatizované testování znalostí uživatelů v projektu StartupJobs.cz

    OpenAIRE

    Mikschik, Filip

    2013-01-01

    This diploma thesis is focused on proposal and implementation of automatized user testing in StartupJobs.cz project. It describes it from theoretical preparation through implemenation to evaluation of this project after first year. It is divided into two main parts. First one is about description of company which is implementing the testing. It describes reasons and expectations from testing implementation. It also creates a theoretical background by describing Classical Test Theory (CTT), It...

  11. Kvalitativní analýza mediálního diskurzu pravicově orientovaného blogu cz.altermedia.info

    OpenAIRE

    Bártová, Kateřina

    2011-01-01

    The thesis called Qualitative Analysis of Media Discourse of the Far-right Blog cz.altermedia.info deals with the discourse analysis of the Czech version of an international project Altermedia.info. Discourse analysis aims at differences between the discourse of the founding editor and the current one and analyses the neo-fascist nature of the blog. The theoretical framework of the analysis is based on the postmarxist theory of discourse introduced by Ernesto Laclau and Chantal Mouffe. The th...

  12. Recent Advances in Silicon Nanomaterial-Based Fluorescent Sensors.

    Science.gov (United States)

    Wang, Houyu; He, Yao

    2017-02-03

    During the past decades, owing to silicon nanomaterials' unique optical properties, benign biocompatibility, and abundant surface chemistry, different dimensional silicon nanostructures have been widely employed for rationally designing and fabricating high-performance fluorescent sensors for the detection of various chemical and biological species. Among of these, zero-dimensional silicon nanoparticles (SiNPs) and one-dimensional silicon nanowires (SiNWs) are of particular interest. Herein, we focus on reviewing recent advances in silicon nanomaterials-based fluorescent sensors from a broad perspective and discuss possible future directions. Firstly, we introduce the latest achievement of zero-dimensional SiNP-based fluorescent sensors. Next, we present recent advances of one-dimensional SiNW-based fluorescent sensors. Finally, we discuss the major challenges and prospects for the development of silicon-based fluorescent sensors.

  13. Optical studies of defects generated in neutron-irradiated Cz-Si during HP-HT treatment

    Energy Technology Data Exchange (ETDEWEB)

    Surma, B.; Wnuk, A. [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Misiuk, A. [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Londos, C.A. [Department of Physics, Panepistimiopolis, GR-15784 Zografos, Athens (Greece); Bukowski, A. [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Silicon CEMAT, Wolczynska 133, 01-919 Warsaw (Poland)

    2005-04-01

    Neutron-irradiated Czochralski grown silicon subjected to heat treatment (HT) at 350 C and 1000 C under enhanced hydrostatic pressure (HP) was studied in this work. It has been shown that external hydrostatic pressure enhances the creation of VO{sub 2} defects in neutron irradiated silicon subjected to the HP-HT treatment at 350 C. Enhanced formation of platelet-like oxygen precipitates was found in the samples treated at 1000 C under 1.1 GPa. This effect was more pronounced in the samples with VO{sub 2} defects. Presented results seem to suggest that probably HP helps to transform VO{sub 2} to some kind of defects or change alone VO{sub 2} defects in the form that can act as an additional nucleus for an additional oxygen precipitation at 1000 C. No correlation between the plate-like oxygen precipitates related absorption at 1225 cm{sup -1} and dislocation-related emission has been confirmed. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Silicone oil induced glaucoma: a review.

    Science.gov (United States)

    Ichhpujani, Parul; Jindal, Anjana; Jay Katz, L

    2009-12-01

    Silicone oil has been an important adjunct for internal tamponade in the treatment of complicated retinal detachment for the past 4 decades. A known complication of its use has been the development of secondary glaucoma. This article reviews the current body of literature documenting the different pathogeneses, predisposing factors and management of silicone oil induced pressure elevation and optic neuropathy. Categorization is clarified for the different types of secondary glaucomas due to silicone oil. Four different mechanisms have been proposed for the pathogenesis of glaucoma that require different therapeutic strategies: (1) overfill with total anterior chamber fill leads to an open-angle glaucoma due to mechanical obstruction of outflow, (2) pupillary block with silicone oil incites angle closure glaucoma, (3) denaturation of silicone oil into microdroplets may sweep into the trabecular meshwork with the development of secondary open angle glaucoma, or (4) finally, inflammation or exacerbation of pre-existing glaucoma. Understanding the risk factors and the pathogenesis of secondary glaucoma when using silicone oil helps guide the timely and appropriate course of treatment.

  15. Oxygen aggregation kinetics, thermal donors and carbon-oxygen defect formation in silicon containing carbon and tin

    Science.gov (United States)

    Angeletos, T.; Sgourou, E. N.; Andrianakis, A.; Diamantopoulou, A.; Chroneos, A.; Londos, C. A.

    2015-07-01

    Localized vibrational mode spectroscopy measurements on Czochralski silicon (Cz-Si) samples subjected to isothermal annealing at 450 °C are reported. First, we studied the effect of carbon (C) and tin (Sn) isovalent dopants on the aggregation kinetics of oxygen. It is determined that the reduction rate of oxygen is described by the Johnson-Mehl-Avrami equation in accordance with previous reports. The activation energy related with the reaction rate constant of the process is calculated to increase from Cz-Si, to C-doped Cz-Si (CCz-Si), to Sn-doped Cz-Si contained C (SnCz-Si). This is attributed to the presence of the isovalent dopants that may impact both the kinetics of the oxygen atoms and also may lead to the formation of other oxygen-related clusters. Second, we studied the effect of Sn on the formation and evolution of carbon-oxygen (C-O) defects. It was determined that the presence of Sn suppresses the formation of the C-O defects as indicated by the reduction in the strength of the 683, 626, and 586 cm-1 well-known bands of CsOi defect. The phenomenon is attributed to the association of Sn with C atoms that may prevent the pairing of O with C. Third, we investigated the effect of C and Sn on the formation of thermal donors (TDs). Regarding carbon our results verified previous reports that carbon suppresses the formation of TDs. Interestingly, when both C and Sn are present in Si, very weak bands of TDs were observed, although it is known that Sn alone suppress their formation. This may be attributed to the competing strains of C and Sn in the Si lattice.

  16. Oxygen aggregation kinetics, thermal donors and carbon-oxygen defect formation in silicon containing carbon and tin

    Energy Technology Data Exchange (ETDEWEB)

    Angeletos, T.; Sgourou, E. N.; Andrianakis, A.; Diamantopoulou, A.; Londos, C. A. [Solid State Section, Physics Department, University of Athens, Panepistimiopolis, Zografos, 157 84 Athens (Greece); Chroneos, A. [Faculty of Engineering and Computing, Coventry University, Priory Street, Coventry CV1 5FB (United Kingdom); Department of Materials, Imperial College London, London SW7 2BP (United Kingdom)

    2015-07-07

    Localized vibrational mode spectroscopy measurements on Czochralski silicon (Cz-Si) samples subjected to isothermal annealing at 450 °C are reported. First, we studied the effect of carbon (C) and tin (Sn) isovalent dopants on the aggregation kinetics of oxygen. It is determined that the reduction rate of oxygen is described by the Johnson-Mehl-Avrami equation in accordance with previous reports. The activation energy related with the reaction rate constant of the process is calculated to increase from Cz-Si, to C-doped Cz-Si (CCz-Si), to Sn-doped Cz-Si contained C (SnCz-Si). This is attributed to the presence of the isovalent dopants that may impact both the kinetics of the oxygen atoms and also may lead to the formation of other oxygen-related clusters. Second, we studied the effect of Sn on the formation and evolution of carbon-oxygen (C-O) defects. It was determined that the presence of Sn suppresses the formation of the C-O defects as indicated by the reduction in the strength of the 683, 626, and 586 cm{sup −1} well-known bands of C{sub s}O{sub i} defect. The phenomenon is attributed to the association of Sn with C atoms that may prevent the pairing of O with C. Third, we investigated the effect of C and Sn on the formation of thermal donors (TDs). Regarding carbon our results verified previous reports that carbon suppresses the formation of TDs. Interestingly, when both C and Sn are present in Si, very weak bands of TDs were observed, although it is known that Sn alone suppress their formation. This may be attributed to the competing strains of C and Sn in the Si lattice.

  17. Zeta function of the projective curve aY2 l = bX2 l + cZ2 l aY2 l = bX2 ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Zeta function of the projective curve aY2 l = bX2 l + cZ2 l. aY2 l = bX2 l + cZ2 l. aY2 l = bX2 l + cZ2 l over a class of finite fields, for odd primes l. N ANURADHA. Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600 113, India. E-mail: anuradha@imsc.res.in. MS received 18 June 2003. Abstract. Let p and ...

  18. Silicon spintronics: Progress and challenges

    Science.gov (United States)

    Sverdlov, Viktor; Selberherr, Siegfried

    2015-07-01

    Electron spin attracts much attention as an alternative to the electron charge degree of freedom for low-power reprogrammable logic and non-volatile memory applications. Silicon appears to be the perfect material for spin-driven applications. Recent progress and challenges regarding spin-based devices are reviewed. An order of magnitude enhancement of the electron spin lifetime in silicon thin films by shear strain is predicted and its impact on spin transport in SpinFETs is discussed. A relatively weak coupling between spin and effective electric field in silicon allows magnetoresistance modulation at room temperature, however, for long channel lengths. Due to tunneling magnetoresistance and spin transfer torque effects, a much stronger coupling between the spin (magnetization) orientation and charge current is achieved in magnetic tunnel junctions. Magnetic random access memory (MRAM) built on magnetic tunnel junctions is CMOS compatible and possesses all properties needed for future universal memory. Designs of spin-based non-volatile MRAM cells are presented. By means of micromagnetic simulations it is demonstrated that a substantial reduction of the switching time can be achieved. Finally, it is shown that any two arbitrary memory cells from an MRAM array can be used to perform a logic operation. Thus, an intrinsic non-volatile logic-in-memory architecture can be realized.

  19. Silicon spintronics: Progress and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Sverdlov, Viktor; Selberherr, Siegfried, E-mail: Selberherr@TUWien.ac.at

    2015-07-14

    Electron spin attracts much attention as an alternative to the electron charge degree of freedom for low-power reprogrammable logic and non-volatile memory applications. Silicon appears to be the perfect material for spin-driven applications. Recent progress and challenges regarding spin-based devices are reviewed. An order of magnitude enhancement of the electron spin lifetime in silicon thin films by shear strain is predicted and its impact on spin transport in SpinFETs is discussed. A relatively weak coupling between spin and effective electric field in silicon allows magnetoresistance modulation at room temperature, however, for long channel lengths. Due to tunneling magnetoresistance and spin transfer torque effects, a much stronger coupling between the spin (magnetization) orientation and charge current is achieved in magnetic tunnel junctions. Magnetic random access memory (MRAM) built on magnetic tunnel junctions is CMOS compatible and possesses all properties needed for future universal memory. Designs of spin-based non-volatile MRAM cells are presented. By means of micromagnetic simulations it is demonstrated that a substantial reduction of the switching time can be achieved. Finally, it is shown that any two arbitrary memory cells from an MRAM array can be used to perform a logic operation. Thus, an intrinsic non-volatile logic-in-memory architecture can be realized.

  20. Liquid Silicon Pouch Anode

    Science.gov (United States)

    2017-09-06

    Docket No. 300139 1 of 13 LIQUID SILICON POUCH ANODE STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured... silicon -based anodes during cycling, lithium insertion and deinsertion. Mitigation of this problem has long been sought and will result in improved...with other potential lithium alloy materials such as gallium and tin. Silicon -based solid state anodes are typically composed of small particles of

  1. Silicon spin communication

    OpenAIRE

    Dery, Hanan; Song, Yang; Li, Pengke; Zutic, Igor

    2011-01-01

    Recent experimental breakthroughs have demonstrated that the electron spin in silicon can be reliably injected and detected as well as transferred over distances exceeding 1 mm. We propose an on-chip communication paradigm which is based on modulating spin polarization of a constant current in silicon wires. We provide figures of merit for this scheme by studying spin relaxation and drift-diffusion models in silicon.

  2. Handbook of silicon photonics

    CERN Document Server

    Pavesi, Lorenzo

    2013-01-01

    The development of integrated silicon photonic circuits has recently been driven by the Internet and the push for high bandwidth as well as the need to reduce power dissipation induced by high data-rate signal transmission. To reach these goals, efficient passive and active silicon photonic devices, including waveguide, modulators, photodetectors, multiplexers, light sources, and various subsystems, have been developed that take advantage of state-of-the-art silicon technology.

  3. Development of an In-line Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells: Final Technical Report, 2 August 2002-15 November 2004

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R. A.

    2004-12-01

    The objective of this subcontract over its two-phase, two-year duration was to design and develop improvements to the existing Sinton Consulting R&D minority-carrier lifetime testers. The improvements enable the possibilities for performing various in-line diagnostics on crystalline silicon wafers and cells for solar cell manufacturing lines. This facilitates manufacturing optimization and improved process control. The scope of work for Phase I was to prototype industrial applications for the improved instruments. A small-sample-head version of the instrument was designed and developed in this effort. This new instrument was complemented by detailed application notes detailing the productive use of minority-carrier lifetime measurements for process optimization and routine process control. In Phase II, the results from the first year were applied to design new instruments for industrial applications. These instruments were then characterized and documented. We report here on four new instruments, each optimized for a specific application as demanded by industrial customers. The documentation for these instruments was very technical and involved considerable R&D. Applications were developed that applied the latest in R&D on industrial silicon materials. By investigating the compromises that would be necessary to measure industrial material directly without the sample preparation that is commonly done for good research, we were able to develop several very innovative applications that can now be done directly in the production line for process control.

  4. Silicon web process development

    Science.gov (United States)

    Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Skutch, M. E.; Driggers, J. M.; Hopkins, R. H.

    1981-01-01

    The silicon web process takes advantage of natural crystallographic stabilizing forces to grow long, thin single crystal ribbons directly from liquid silicon. The ribbon, or web, is formed by the solidification of a liquid film supported by surface tension between two silicon filaments, called dendrites, which border the edges of the growing strip. The ribbon can be propagated indefinitely by replenishing the liquid silicon as it is transformed to crystal. The dendritic web process has several advantages for achieving low cost, high efficiency solar cells. These advantages are discussed.

  5. Study of double porous silicon surfaces for enhancement of silicon solar cell performance

    Science.gov (United States)

    Razali, N. S. M.; Rahim, A. F. A.; Radzali, R.; Mahmood, A.

    2017-09-01

    In this work, design and simulation of double porous silicon surfaces for enhancement of silicon solar cell is carried out. Both single and double porous structures are constructed by using TCAD ATHENA and TCAD DEVEDIT tools of the SILVACO software respectively. After the structures were created, I-V characteristics and spectral response of the solar cell were extracted using ATLAS device simulator. Finally, the performance of the simulated double porous solar cell is compared with the performance of both single porous and bulk-Si solar cell. The results showed that double porous silicon solar cell exhibited 1.8% efficiency compared to 1.3% and 1.2% for single porous silicon and bulk-Si solar cell.

  6. Wybrane farmakokinetyczne interakcje leków w trakcie leczenia padaczki. Część I

    Directory of Open Access Journals (Sweden)

    Magdalena Justyna Kacperska

    2013-04-01

    Full Text Available Padaczka jest jedną z najdłużej znanych chorób. Słowo epilepsia liczy 2500 lat i pochodzi od greckiego epilamvanein, co znaczy ‘atakować’, ‘chwycić’, ‘posiąść’. Napady padaczkowe traktowane były jako wyraz owładnięcia przez demony, złe duchy, w związku z czym padaczkę przez długi czas uważano za „świętą chorobę”. Nie jest to choroba w klasycznym znaczeniu, a raczej skomplikowany proces patofizjologiczny, którego bardzo liczne i złożone objawy są wynikiem różnych zaburzeń funkcji mózgu. Padaczka należy do najtrudniejszych problemów neuroepidemiologicznych. Napady padaczkowe są wyrazem patologicznej czynności różnych obszarów mózgu w przebiegu wielu procesów chorobowych. Źródłem patologicznych wyładowań w klinicznej formie napadu padaczkowego mogą być blizny pourazowe, zmiany uciskowe, zapalne, zwyrodnieniowe, ogniska naczyniopochodne czy zaburzenia rozwojowe. Ogniskiem padaczkowym jest strefa zmienionej tkanki, leżącej między uszkodzeniem a okolicą zdrową. To grupa neuronów generująca okresowo napadową czynność bioelektryczną w formie napadowych wy- ładowań depolaryzacyjnych generujących kliniczny napad padaczkowy. Większość padaczek to zaburzenia pierwotne mózgowe, choć istnieje również wiele procesów pozamózgowych zaburzających homeostazę ustrojową. W leczeniu padaczki nie występuje jeden standardowy sposób postępowania. Celem terapii jest całkowita kontrola napadów i uzyskanie jak najmniejszych objawów niepożądanych podczas leczenia lekami przeciwpadaczkowymi. Wiedza i doświadczenie lekarzy praktyków są najistotniejszym czynnikiem wpływającym na opiekę nad chorym z padaczką. Lek powinien być dostosowany do typu napadu lub zespołu padaczkowego, częstości i ciężkości napadów. Pojawienie się leków nowej generacji dało im pewną przewagę w stosunku do starszych leków. Cechują je: większa swoistość działania, lepsze w

  7. Role of water in the tribochemical removal of bare silicon

    Science.gov (United States)

    Chen, Cheng; Xiao, Chen; Wang, Xiaodong; Zhang, Peng; Chen, Lei; Qi, Yaqiong; Qian, Linmao

    2016-12-01

    Nanowear tests of bare silicon against a SiO2 microsphere were conducted in air (relative humidity [RH] = 0%-89%) and water using an atomic force microscope. Experimental results revealed that the water played an important role in the tribochemical wear of the bare silicon. A hillock-like wear trace with a height of 0.7 nm was generated on the bare silicon surface in dry air. As the RH increased, the wear depth increased and reached the maximum level in water. Analysis of frictional dissipated energy suggested that the wear of the bare silicon was not dominated by mechanical interactions. High-resolution transmission electron microscopy detection demonstrated that the silicon atoms and crystal lattice underneath the worn area maintained integral perfectly and thus further confirmed the tribochemical wear mechanism of the bare silicon. Finally, the role of water in the tribochemical wear of the bare silicon may be explained by the following three aspects: the hydroxylation by hydroxyl ions auto-ionized in water, the hydrolytic reaction of water molecules, and the dissolution of the tribochemical product SiOmHn in liquid water. With increasing RH, a greater water amount would adsorb to the Si/SiO2 interface and induce a more serious tribochemical wear on the bare silicon surface. The results of this paper may provide further insight into the tribochemical removal mechanism of bare monocrystalline silicon and furnish the wider reaction cognition for chemical mechanical polishing.

  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. ALICE silicon strip module

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    This small silicon detector strip will be inserted into the inner tracking system (ITS) on the ALICE detector at CERN. This detector relies on state-of-the-art particle tracking techniques. These double-sided silicon strip modules have been designed to be as lightweight and delicate as possible as the ITS will eventually contain five square metres of these devices.

  10. Silicon Valley: Planet Startup

    NARCIS (Netherlands)

    Dr. P. Ester; dr. A. Maas

    2016-01-01

    For decades now, Silicon Valley has been the home of the future. It's the birthplace of the world's most successful high-tech companies-including Apple, Yahoo, Google, Facebook, Twitter, and many more. So what's the secret? What is it about Silicon Valley that fosters entrepreneurship and

  11. Advances in silicon nanophotonics

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Pu, Minhao

    plasma effect have been tested up to 40 Gbit/s, and hybrid evanescent silicon lasers have been realized both in the form of distributed feed-back lasers and micro-disk lasers. For enhancing the impact of silicon photonics in future ultrafast and energy-efficient all-optical signal processing, e......Silicon has long been established as an ideal material for passive integrated optical circuitry due to its high refractive index, with corresponding strong optical confinement ability, and its low-cost CMOS-compatible manufacturability. However, the inversion symmetry of the silicon crystal lattice...... has been an obstacle for a simple realization of electro-optic modulators, and its indirect band gap has prevented the realization of efficient silicon light emitting diodes and lasers. Still, significant progress has been made in the past few years. Electro-optic modulators based on the free carrier...

  12. Silicone-containing composition

    Science.gov (United States)

    Mohamed, Mustafa

    2012-01-24

    A silicone-containing composition comprises the reaction product of a first component and an excess of an isocyanate component relative to the first component to form an isocyanated intermediary. The first component is selected from one of a polysiloxane and a silicone resin. The first component includes a carbon-bonded functional group selected from one of a hydroxyl group and an amine group. The isocyanate component is reactive with the carbon-bonded functional group of the first component. The isocyanated intermediary includes a plurality of isocyanate functional groups. The silicone-containing composition comprises the further reaction product of a second component, which is selected from the other of the polysiloxane and the silicone resin. The second component includes a plurality of carbon-bonded functional groups reactive with the isocyanate functional groups of the isocyanated intermediary for preparing the silicone-containing composition.

  13. Intraventricular Silicone Oil

    Science.gov (United States)

    Mathis, Stéphane; Boissonnot, Michèle; Tasu, Jean-Pierre; Simonet, Charles; Ciron, Jonathan; Neau, Jean-Philippe

    2016-01-01

    Abstract Intracranial silicone oil is a rare complication of intraocular endotamponade with silicone oil. We describe a case of intraventricular silicone oil fortuitously observed 38 months after an intraocular tamponade for a complicated retinal detachment in an 82 year-old woman admitted in the Department of Neurology for a stroke. We confirm the migration of silicone oil along the optic nerve. We discuss this rare entity with a review of the few other cases reported in the medical literature. Intraventricular migration of silicone oil after intraocular endotamponade is usually asymptomatic but have to be known of the neurologists and the radiologists because of its differential diagnosis that are intraventricular hemorrhage and tumor. PMID:26735537

  14. Soil weed seed bank at ploughingl layer on the Nałęczów Plateau in relation to cereal crops and sculpture elements

    Directory of Open Access Journals (Sweden)

    Marian Wesołowski

    2013-12-01

    Full Text Available The weed seed bank in the ploughing layer (0-25 cm deep of loess soils, located at top, slope and slope foot, is presented in the papaer. Soil samples, taken just affer the harvest of winter and spring cereals, in the Nal9cz6w surroundings (east-middle Poland were the investigative material. It was proved that the most of weed seeds and fruits were the winter cereals bocated at the slopes and slopes foot. The diaspors of short-lived weeds were dominant III-V degree of stability in the soil covered all sculpture elements.

  15. Silicon germanium mask for deep silicon etching

    KAUST Repository

    Serry, Mohamed

    2014-07-29

    Polycrystalline silicon germanium (SiGe) can offer excellent etch selectivity to silicon during cryogenic deep reactive ion etching in an SF.sub.6/O.sub.2 plasma. Etch selectivity of over 800:1 (Si:SiGe) may be achieved at etch temperatures from -80 degrees Celsius to -140 degrees Celsius. High aspect ratio structures with high resolution may be patterned into Si substrates using SiGe as a hard mask layer for construction of microelectromechanical systems (MEMS) devices and semiconductor devices.

  16. Transformational silicon electronics

    KAUST Repository

    Rojas, Jhonathan Prieto

    2014-02-25

    In today\\'s traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 μm), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry\\'s most advanced high-κ/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications. © 2014 American Chemical Society.

  17. Transformational silicon electronics.

    Science.gov (United States)

    Rojas, Jhonathan Prieto; Torres Sevilla, Galo Andres; Ghoneim, Mohamed Tarek; Inayat, Salman Bin; Ahmed, Sally M; Hussain, Aftab Mustansir; Hussain, Muhammad Mustafa

    2014-02-25

    In today's traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 μm), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry's most advanced high-κ/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications.

  18. Enhanced extraction of silicon-vacancy centers light emission using bottom-up engineered polycrystalline diamond photonic crystal slabs

    Czech Academy of Sciences Publication Activity Database

    Ondič, Lukáš; Varga, Marián; Hruška, Karel; Fait, J.; Kapusta, Peter

    2017-01-01

    Roč. 11, č. 3 (2017), s. 2972-2981 ISSN 1936-0851 R&D Projects: GA ČR GJ16-09692Y; GA MŠk LD15003; GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:68378271 ; RVO:61388955 Keywords : photonic crystal * diamond * silicon vacancy center Subject RIV: BM - Solid Matter Physics ; Magnetism; CF - Physical ; Theoretical Chemistry (UFCH-W) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Physical chemistry (UFCH-W) Impact factor: 13.942, year: 2016

  19. Znaczenie badań farmakogenetycznych w efektywności leczenia metotreksatem chorych na reumatoidalne zapalenie stawów (część 2

    Directory of Open Access Journals (Sweden)

    Jerzy Świerkot

    2011-01-01

    Full Text Available Obecnie dużą nadzieję wiąże się z indywidualizacją leczenia chorych na reumatoidalne zapalenie stawów (RZS. Trwają poszukiwania markerów biochemicznych i klinicznych, dzięki którym można by przewidzieć dobrą odpowiedź na leczenie metotreksatem (MTX. Oprócz czynników klinicznych pomocna w jej ustaleniu może być predyspozycja genetyczna. Polimorfizm genów biorących udział w metabolizmie MTX może wpływać na jego skuteczność i częstość występowania działań niepożądanych. Badania farmakogenetyczne mogą się przyczynić do skuteczniejszej indywidualizacji leczenia chorych na RZS. W pracy określono znaczenie polimorfizmów genów reduktazy metylenotetrahydrofolianowej MTHFR C677T i A1298C na efektywność terapii MTX u chorych na RZS. Obecność określonych polimorfizmów genowych związanych z możliwością wystąpienia działań niepożądanych powinna być związana ze szczególnie wnikliwą oceną chorych.

  20. Transport rumowiska w rzekach. Część II: prędkość graniczna oraz natężenie wleczenia

    Directory of Open Access Journals (Sweden)

    Mateusz Hämmerling

    2014-12-01

    Full Text Available W pracy przedstawiono dalszy ciąg opisu początku ruchu rumowiska w na­ wiązaniu do części I artykułu. Artykuł omawia prędkości graniczne, takie jak prędkość nierozmywającą, prędkość, przy której ziarna pozostają jeszcze w spoczynku. Przywołane wzory opisujące prędkości graniczne, stworzyli różni autorzy dla zmiennej charakterystyki rumowiska i warunków przepływu. W części tej również przedstawiono wybrane wzory pozwalające wyznaczyć intensywność transportu rumowiska i wpływ kryterium przyjętego do określenia początku ruchu ziarna na wyniki obliczeń.

  1. Silicon nanowire hybrid photovoltaics

    KAUST Repository

    Garnett, Erik C.

    2010-06-01

    Silicon nanowire Schottky junction solar cells have been fabricated using n-type silicon nanowire arrays and a spin-coated conductive polymer (PEDOT). The polymer Schottky junction cells show superior surface passivation and open-circuit voltages compared to standard diffused junction cells with native oxide surfaces. External quantum efficiencies up to 88% were measured for these silicon nanowire/PEDOT solar cells further demonstrating excellent surface passivation. This process avoids high temperature processes which allows for low-cost substrates to be used. © 2010 IEEE.

  2. 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.

  3. Silicon tracker for LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bencze, G.; Bosteels, M.; Brenner, R.; Czellar, S.; Ekman, K.; Hentinen, A.; Hietanen, I.; Huhtinen, M.; Inkinen, S.; Karimaeki, V.; Karttaavi, T.; Kinnunen, R.; Lindgren, J.; Merlo, J.P.; Oksakivi, T.; Onnela, A.; Orava, R.; Pietarinen, E.; Pimiae, M.; Roth, W.; Roennqvist, C.; Saarikko, J.P.; Schulman, T.; Tuuva, T.; Voutilainen, M.; Vuoskoski, J.; Oesterberg, K. (Research Inst. for High Energy Physics, SEFT, Helsinki (Finland) Physics Dept., Univ. of Helsinki (Finland) Univ. of Technology, Helsinki, Espoo (Finland) AAbo Akademi, Domkyrkotorget, Turku (Finland) Univ. of Technology, Tampere (Finland) DAPNIA, Centre d' Etudes Nucleaires, 91 Gif-sur-Yvette, Saclay (France) CERN, Geneva (Switzerland))

    1993-05-01

    A study of a possible layout of a Silicon tracker has been done. The design is based on simulations done in the context of the Compact Muon Solenoid (CMS) detector for the LHC. The high granularity of the silicon strip detectors yields to low occupancies. New type of a silicon strip detector, single sided stereo angle detector (SSSD), has been designed to match the requirements of a LHC tracker. This detector allows a z-coordinate measurement without increasing the number of channels i.e. power consumption and it facilitates a tracker design with reasonable complicity. (orig.)

  4. Effect of Silicon in U-10Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kautz, Elizabeth J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kovarik, Libor [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-08-31

    This document details a method for evaluating the effect of silicon impurity content on U-10Mo alloys. Silicon concentration in U-10Mo alloys has been shown to impact the following: volume fraction of precipitate phases, effective density of the final alloy, and 235-U enrichment in the gamma-UMo matrix. This report presents a model for calculating these quantities as a function of Silicon concentration, which along with fuel foil characterization data, will serve as a reference for quality control of the U-10Mo final alloy Si content. Additionally, detailed characterization using scanning electron microscope imaging, transmission electron microscope diffraction, and atom probe tomography showed that Silicon impurities present in U-10Mo alloys form a Si-rich precipitate phase.

  5. Advanced silicon on insulator technology

    Science.gov (United States)

    Godbey, D.; Hughes, H.; Kub, F.

    1991-01-01

    Undoped, thin-layer silicon-on-insulator was fabricated using wafer bonding and selective etching techniques employing a molecular beam epitaxy (MBE) grown Si0.7Ge0.3 layer as an etch stop. Defect free, undoped 200-350 nm silicon layers over silicon dioxide are routinely fabricated using this procedure. A new selective silicon-germanium etch was developed that significantly improves the ease of fabrication of the bond and etch back silicon insulator (BESOI) material.

  6. Silicon microfabricated beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Othman, A., E-mail: aliman@ppinang.uitm.edu.my; Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A. [Faculty of Electrical Engineering, Universiti Teknologi MARA Malaysia, 40450, Shah Alam, Selangor (Malaysia); Ain, M. F. [School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300,Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-30

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  7. Porous Silicon Nanowires

    Science.gov (United States)

    Qu, Yongquan; Zhou, Hailong; Duan, Xiangfeng

    2011-01-01

    In this minreview, we summarize recent progress in the synthesis, properties and applications of a new type of one-dimensional nanostructures — single crystalline porous silicon nanowires. The growth of porous silicon nanowires starting from both p- and n-type Si wafers with a variety of dopant concentrations can be achieved through either one-step or two-step reactions. The mechanistic studies indicate the dopant concentration of Si wafers, oxidizer concentration, etching time and temperature can affect the morphology of the as-etched silicon nanowires. The porous silicon nanowires are both optically and electronically active and have been explored for potential applications in diverse areas including photocatalysis, lithium ion battery, gas sensor and drug delivery. PMID:21869999

  8. ALICE Silicon Pixel Detector

    CERN Multimedia

    2003-01-01

    The Silicon Pixel Detector (SPD) is part of the Inner Tracking System (ITS) of the ALICE experiment : . SPD Structure . Bump Bonding . Test beam . ALICE1LHCb Readout Chip . Chip Tests . Data from the SPD

  9. Silicon production process evaluations

    Science.gov (United States)

    1982-05-01

    Engineering design of the third distillation column in the process was accomplished. The initial design is based on a 94.35% recovery of dichlorosilane in the distillate and a 99.9% recovery of trichlorosilane in the bottoms. The specified separation is achieved at a reflux ratio of 15 with 20 trays (equilibrium stages). Additional specifications and results are reported including equipment size, temperatures and pressure. Specific raw material requirements necessary to produce the silicon in the process are presented. The primary raw materials include metallurgical grade silicon, silicon tetrachloride, hydrogen, copper (catalyst) and lime (waste treatment). Hydrogen chloride is produced as by product in the silicon deposition. Cost analysis of the process was initiated during this reporting period.

  10. Amorphous silicon crystalline silicon heterojunction solar cells

    CERN Document Server

    Fahrner, Wolfgang Rainer

    2013-01-01

    Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to "fill in the blanks" on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the current developmental states of the devices. Prof. Dr. Wolfgang R. Fahrner is a professor at the University of Hagen, Germany and Nanchang University, China.

  11. 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.

  12. Silicon-Based Light Sources for Silicon Integrated Circuits

    Directory of Open Access Journals (Sweden)

    L. Pavesi

    2008-01-01

    Full Text Available Silicon the material per excellence for electronics is not used for sourcing light due to the lack of efficient light emitters and lasers. In this review, after having introduced the basics on lasing, I will discuss the physical reasons why silicon is not a laser material and the approaches to make it lasing. I will start with bulk silicon, then I will discuss silicon nanocrystals and Er3+ coupled silicon nanocrystals where significant advances have been done in the past and can be expected in the near future. I will conclude with an optimistic note on silicon lasing.

  13. Silicon Germanium Cryogenic Low Noise Amplifiers

    Science.gov (United States)

    Bardin, J. C.; Montazeri, S.; Chang, Su-Wei

    2017-05-01

    Silicon germanium heterojunction bipolar transistors have emerged in the last decade as an excellent option for use in cryogenic low noise amplifiers. This paper begins with a review of the critical developments that have led to today’s cryogenic low noise amplifiers. Next, recent work focused on minimizing the power consumption of SiGe cryogenic amplifiers is presented. Finally, open issues related to the cryogenic noise properties of SiGe HBTs are discussed.

  14. Industrial Silicon Wafer Solar Cells

    Directory of Open Access Journals (Sweden)

    Dirk-Holger Neuhaus

    2007-01-01

    Full Text Available In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future efficiency potential of this technology. In research and development, more various advanced solar cell concepts have demonstrated higher efficiencies. The question which arises is “why are new solar cell concepts not transferred into industrial production more frequently?”. We look into the requirements a new solar cell technology has to fulfill to have an advantage over the current approach. Finally, we give an overview of high-efficiency concepts which have already been transferred into industrial production.

  15. Znaczenie badań farmakogenetycznych w efektywności leczenia metotreksatem chorych na reumatoidalne zapalenie stawów (część 1

    Directory of Open Access Journals (Sweden)

    Jerzy Świerkot

    2011-01-01

    Full Text Available Metotreksat (MTX jest nadal złotym standardem w leczeniu RZS i jest stosowany na świecie u ponad 0,5 mln chorych na RZS. Obecnie dużą nadzieję wiąże się z indywidualizacją leczenia chorych na RZS. Oprócz czynników klinicznych pomocna w jej ustaleniu może być predyspozycja genetyczna. Polimorfizm genów biorących udział w metabolizmie MTX może wpływać na jego skuteczność i częstość występowania działań niepożądanych. Badania farmakogenetyczne mogą się przyczynić do skuteczniejszej indywidualizacji leczenia chorych na RZS. Istnieje wiele potencjalnych enzymów i białek transportujących występujących w postaciach polimorficznych, które biorą udział w transporcie MTX do komórki, jego metabolizmie i wydalaniu z komórki. Obecnie próbuje się określić przydatność badań polimorfizmów genów do oceny skuteczności leczenia i występowania potencjalnych działań niepożądanych biorąc pod uwagę analizę farmakoekonomiczną. Istnieje szansa, że w przyszłości dzięki indywidualizacji terapii będziemy mogli dostosowywać leczenie (rodzaj leku, dawka leku, droga podania do danego molekularnego podtypu choroby oraz genotypu chorego. Chorzy, u których występują niekorzystne polimorfizmy mogliby być leczeni innymi LMPCH lub już od początku wdrożono by terapię kombinowaną, a w razie niepowodzenia leczenie biologiczne. Chorzy z określonym typem polimorfizmu wymagaliby częstszej kontroli reumatologicznej oceniającej skuteczność i bezpieczeństwo leczenia. Należy jednak pamiętać, że predyspozycje genetyczne są tylko jednymi z czynników wpływających na różnice podczas farmakoterapii u poszczególnych chorych.

  16. Fabrication and Characterisation of Silicon Waveguides for High-Speed Optical Signal Processing

    DEFF Research Database (Denmark)

    Jensen, Asger Sellerup

    silicon waveguides. As an alternative to crystalline silicon waveguides for nonlinear optical applications, amorphous silicon was explored using RF sputtering potentially allowing for low density of detrimental hydrogen content in the final material. Unfortunately, the linear optical loss in the material...... was too high for any practical applications. It is speculated that the attempt at creating a material with low density of dangling bonds was unsuccessful. Nevertheless, linear losses of 2.4dB/cm at 1550nm wavelength in the silicon waveguides remained sufficiently low that high speed nonlinear optical...... signal processing could be demonstrated. This includes four wave mixing based wavelength conversion of a 320Gb/s Nyquist OTDM signal and cross phase modulation based signal regeneration of a 40Gb/s OTDM signal. Finally, a new type of low loss electrically driven optical modulator in silicon and silicon...

  17. Microcrystalline silicon prepared at magnetic field modified nucleation

    Czech Academy of Sciences Publication Activity Database

    Kočka, Jan; Mates, Tomáš; Ledinský, Martin; Stuchlíková, The-Ha; Stuchlík, Jiří; Fejfar, Antonín

    2006-01-01

    Roč. 352, - (2006), s. 901-905 ISSN 0022-3093 R&D Projects: GA MŽP(CZ) SM/300/1/03; GA MŽP(CZ) SN/3/172/05; GA AV ČR(CZ) IAA1010316; GA AV ČR(CZ) IAA1010413; GA MŠk(CZ) LC510 Institutional research plan: CEZ:AV0Z10100521 Keywords : amorphous semiconductors * nucleation * electrical and electronic properties * chemical vapor deposition * atomic force and scanning tunneling microscopy * microcrystallinity * optical properties Subject RIV: BM - Solid Matter Physics ; Magnet ism Impact factor: 1.362, year: 2006

  18. Gallium-Doped Poly-Si:Ga/SiO2 Passivated Emitters to n-Cz Wafers With iV oc >730 mV

    Energy Technology Data Exchange (ETDEWEB)

    Young, David L.; Lee, Benjamin G.; Fogel, Derek; Nemeth, William; LaSalvia, Vincenzo; Theingi, San; Page, Matthew; Young, Matthew; Perkins, Craig; Stradins, Paul

    2017-11-01

    We form gallium-doped poly-Si:Ga/SiO2 passivated contacts on n-type Czochralski (n-Cz) wafers using ion implantation of Ga and Ga-containing spin-on dopants. After annealing and passivation with Al2O3 , the contacts exhibit iVoc values of >730 mV with corresponding Joe values of <5 fA/cm2 . These are among the best-reported values for p-type poly-Si/SiO2 contacts. Secondary ion mass spectroscopic depth profile data show that, in contrast to B, Ga does not pileup at the SiO2 interface in agreement with its known high diffusivity in SiO2. This lack of Ga pileup may imply fewer dopant-related defects in the SiO2, compared with B dopants, and account for the excellent passivation.

  19. The use of Holt–Winters method for forecasting the amount of sewage inflowing into the wastewater treatment plant in Nowy Sącz

    Directory of Open Access Journals (Sweden)

    Wąsik Ewa

    2016-06-01

    Full Text Available The aim of the study was to determine changes of daily amount of sewage inflowing into a wastewater treatment plant in Nowy Sącz in the years 2008-2014. To this end, the data in the form of time series corresponding to the investigated multi-year period were analysed. Daily volume of sewage for annual periods was forecast using a seasonal method of Holt and Winters based on the exponential smoothing algorithms. The model fit to actual daily amount of sewage for 2014 was assessed using linear regression. The results of fit for the additive Holt-Winters model confirmed the usefulness of this tool for forecasting the amount of sewage inflowing into the wastewater treatment plant.

  20. Silicon Based Anodes for Li-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiguang; Wang, Wei; Xiao, Jie; Xu, Wu; Graff, Gordon L.; Yang, Zhenguo; Choi, Daiwon; Li, Xiaolin; Wang, Deyu; Liu, Jun

    2012-06-15

    Silicon is environmentally benign and ubiquitous. Because of its high specific capacity, it is considered one of the most promising candidates to replace the conventional graphite negative electrode used in today's Li ion batteries. Silicon has a theoretical specific capacity of nearly 4200 mAh/g (Li21Si5), which is 10 times larger than the specific capacity of graphite (LiC6, 372 mAh/g). However, the high capacity of silicon is associated with huge volume changes (more than 300 percent) when alloyed with lithium, which can cause severe cracking and pulverization of the electrode and lead to significant capacity loss. Significant scientific research has been conducted to circumvent the deterioration of silicon based anode materials during cycling. Various strategies, such as reduction of particle size, generation of active/inactive composites, fabrication of silicon based thin films, use of alternative binders, and the synthesis of 1-D silicon nanostructures have been implemented by a number of research groups. Fundamental mechanistic research has also been performed to better understand the electrochemical lithiation and delithiation process during cycling in terms of crystal structure, phase transitions, morphological changes, and reaction kinetics. Although efforts to date have not attained a commercially viable Si anode, further development is expected to produce anodes with three to five times the capacity of graphite. In this chapter, an overview of research on silicon based anodes used for lithium-ion battery applications will be presented. The overview covers electrochemical alloying of the silicon with lithium, mechanisms responsible for capacity fade, and methodologies adapted to overcome capacity degradation observed during cycling. The recent development of silicon nanowires and nanoparticles with significantly improved electrochemical performance will also be discussed relative to the mechanistic understanding. Finally, future directions on the

  1. Laser-zone Growth in a Ribbon-to-ribbon (RTR) Process Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Solar Array Project

    Science.gov (United States)

    Baghdadi, A.; Gurtler, R. W.; Legge, R.; Sopori, B.; Rice, M. J.; Ellis, R. J.

    1979-01-01

    A technique for growing limited-length ribbons continually was demonstrated. This Rigid Edge technique can be used to recrystallize about 95% of the polyribbon feedstock. A major advantage of this method is that only a single, constant length silicon ribbon is handled throughout the entire process sequence; this may be accomplished using cassettes similar to those presently in use for processing Czochralski waters. Thus a transition from Cz to ribbon technology can be smoothly affected. The maximum size being considered, 3 inches x 24 inches, is half a square foot, and will generate 6 watts for 12% efficiency at 1 sun. Silicon dioxide has been demonstrated as an effective, practical diffusion barrier for use during the polyribbon formation.

  2. Nanoslits in silicon chips.

    Science.gov (United States)

    Aref, Thomas; Brenner, Matthew; Bezryadin, Alexey

    2009-01-28

    Potassium hydroxide (KOH) etching of a patterned [100] oriented silicon wafer produces V-shaped etch pits. We demonstrate that the remaining thickness of silicon at the tip of the etch pit can be reduced to approximately 5 microm using an appropriately sized etch mask and optical feedback. Starting from such an etched chip, we have developed two different routes for fabricating 100 nm scale slits that penetrate through the macroscopic silicon chip (the slits are approximately 850 microm wide at one face of the chip and gradually narrow to approximately 100-200 nm wide at the opposite face of the chip). In the first process, the etched chips are sonicated to break the thin silicon at the tip of the etch pit and then further KOH etched to form a narrow slit. In the second process, focused ion beam milling is used to etch through the thin silicon at the tip of the etch pit. The first method has the advantage that it uses only low-resolution technology while the second method offers more control over the length and width of the slit. Our slits can be used for preparing mechanically stable, transmission electron microscopy samples compatible with electrical transport measurements or as nanostencils for depositing nanowires seamlessly connected to their contact pads.

  3. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

  4. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hameed A. Naseem, Husam H. Abu-Safe

    2007-02-09

    The purpose of this project was to investigate metal-induced crystallization of amorphous silicon at low temperatures using excitation sources such as laser and rapid thermal annealing, as well as, electric field. Deposition of high quality crystalline silicon at low temperatures allows the use of low cost soda-lime glass and polymeric films for economically viable photovoltaic solar cells and low cost large area flat panel displays. In light of current and expected demands on Si supply due to expanding use of consumer electronic products throughout the world and the incessant demand for electric power the need for developing high grade Si thin films on low cost substrate becomes even more important. We used hydrogenated and un-hydrogenated amorphous silicon deposited by plasma enhanced chemical vapor deposition and sputtering techniques (both of which are extensively used in electronic and solar cell industries) to fabricate nano-crystalline, poly-crystalline (small as well as large grain), and single-crystalline (epitaxial) films at low temperatures. We demonstrated Si nanowires on flat surfaces that can be used for fabricating nanometer scale transistors. We also demonstrated lateral crystallization using Al with and without an applied electric field. These results are critical for high mobility thin film transistors (TFT) for large area display applications. Large grain silicon (~30-50 µm grain size for < 0.5 µm thick films) was demonstrated on glass substrates at low temperatures. We also demonstrated epitaxial growth of silicon on (100) Si substrates at temperatures as low as 450°C. Thin film Si solar cells are being projected as the material of choice for low cost high efficiency solar cells when properly coupled with excellent light-trapping schemes. Ar ion laser (CW) was shown to produce dendritic nanowire structures at low power whereas at higher powers yielded continuous polycrystalline films. The power density required for films in contact with Al

  5. Silicon Bulk Micromachined Vibratory Gyroscope

    Science.gov (United States)

    Tang, T. K.; Gutierrez, R. C.; Wilcox, J. Z.; Stell, C.; Vorperian, V.; Calvet, R.; Li, W. J.; Charkaborty, I.; Bartman, R.; Kaiser, W. J.

    1996-01-01

    This paper reports on design, modeling, fabrication, and characterization of a novel silicon bulk micromachined vibratory rate gyroscope designed for microspacecraft applications. The new microgyroscope consists of a silicon four leaf cloverstructure with a post attached to the center.

  6. Neuromorphic Silicon Neuron Circuits

    Science.gov (United States)

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  7. The LHCb Silicon Tracker

    CERN Document Server

    Vollhardt, A

    2004-01-01

    The LHCb detector is a collider experiment at the new LHC at CERN/Switzerland. It is dedicated to measure precisely CP violation parameters in the B-system. The LHCb Silicon Tracker is covering the regions of the tracking detector with the highest particle fluences. The silicon sensors are wide pitch strip detectors connected to multi-channel analogue readout amplifiers. The analogue data is then digitized and transmitted optically to the counting room for further processing. The following paper describes R&D of the silicon sensors performed including testbeam data. We present readout chip performance followed by an overview of the used data transmission system, which has been designed for radiation tolerance and low cost.

  8. Integrated Silicon Optoelectronics

    CERN Document Server

    Zimmermann, Horst K

    2010-01-01

    Integrated Silicon Optoelectronics synthesizes topics from optoelectronics and microelectronics. The book concentrates on silicon as the major base of modern semiconductor devices and circuits. Starting from the basics of optical emission and absorption, as well as from the device physics of photodetectors, the aspects of the integration of photodetectors in modern bipolar, CMOS, and BiCMOS technologies are discussed. Detailed descriptions of fabrication technologies and applications of optoelectronic integrated circuits are included. The book, furthermore, contains a review of the newest state of research on eagerly anticipated silicon light emitters. In order to cover the topics comprehensively, also included are integrated waveguides, gratings, and optoelectronic power devices. Numerous elaborate illustrations facilitate and enhance comprehension. This extended edition will be of value to engineers, physicists, and scientists in industry and at universities. The book is also recommended to graduate student...

  9. Neuromorphic silicon neuron circuits

    Directory of Open Access Journals (Sweden)

    Giacomo eIndiveri

    2011-05-01

    Full Text Available Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance based Hodgkin-Huxley models to bi-dimensional generalized adaptive Integrate and Fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.

  10. Floating Silicon Method

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  11. Silicon containing copolymers

    CERN Document Server

    Amiri, Sahar; Amiri, Sanam

    2014-01-01

    Silicones have unique properties including thermal oxidative stability, low temperature flow, high compressibility, low surface tension, hydrophobicity and electric properties. These special properties have encouraged the exploration of alternative synthetic routes of well defined controlled microstructures of silicone copolymers, the subject of this Springer Brief. The authors explore the synthesis and characterization of notable block copolymers. Recent advances in controlled radical polymerization techniques leading to the facile synthesis of well-defined silicon based thermo reversible block copolymers?are described along with atom transfer radical polymerization (ATRP), a technique utilized to develop well-defined functional thermo reversible block copolymers. The brief also focuses on Polyrotaxanes and their great potential as stimulus-responsive materials which produce poly (dimethyl siloxane) (PDMS) based thermo reversible block copolymers.

  12. Silicon Based Photovoltaic Cells For Concentration-Research And Development Progress In Laser Grooved Buried Contact Cell Technology

    Science.gov (United States)

    Cole, A.; Baistow, I.; Brown, L.; Devenport, S.; Drew, K.; Heasman, K. C.; Morrison, D.; Bruton, T. M.; Serenelli, L.; De Iuliis, S.; Izzi, M.; Tucci, M.; Salza, E.; Pirozzi, L.

    2011-12-01

    The Laser grooved buried contact silicon solar cell (LGBC) process employed by Narec currently produces LGBC cells designed to operate at concentrations ranging from 1-100 suns and has demonstrated efficiencies at 50X of over 19% and at 100X of over 18.2% using 300 μm CZ silicon[1] wafers. As part of the LAB2LINE[1], APOLLON[2] and ASPIS[3] projects funded under the European Commission Framework Programs (FP6 and FP7) we have made improvements to the LGBC process to improve efficiency or make the cell technology more suitable for industrial CPV receiver manufacturing processes. We describe a process which hybridizes LGBC and more standard screen printing technologies which yields at least a 6% relative improvement at concentration when using more readily available 200 μm thick CZ wafers. We describe a pioneering front dicing technique (FDT). The FDT process is important in small cells where edge recombination effects are detrimental to the performance. We show that by using this new technique we can produce cells that perform better at concentration and improve the positioning of the front contact of the cell. We also describe a busbar technology that uses laser processing and electroless chemical plating to allow not only soldering to the front contact of the cell but also wire bonding. The advances in research and development of LGBC cells leading to improved cell performance may provide significant reductions in levilised cost of energy (LCOE) for low to medium CPV systems.

  13. The Silicon Cube detector

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I.; Adimi, N. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Blank, B. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France)], E-mail: blank@cenbg.in2p3.fr; Canchel, G.; Giovinazzo, J. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Borge, M.J.G.; Dominguez-Reyes, R.; Tengblad, O. [Insto. Estructura de la Materia, CSIC, Serrano 113bis, E-28006 Madrid (Spain); Thomas, J.-C. [GANIL, CEA/DSM - CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

    2009-08-21

    A new experimental device, the Silicon Cube detector, consisting of six double-sided silicon strip detectors placed in a compact geometry was developed at CENBG. Having a very good angular coverage and high granularity, it allows simultaneous measurements of energy and angular distributions of charged particles emitted from unbound nuclear states. In addition, large-volume Germanium detectors can be placed close to the collection point of the radioactive species to be studied. The setup is ideally suited for isotope separation on-line (ISOL)-type experiments to study multi-particle emitters and was tested during an experiment at the low-energy beam line of SPIRAL at GANIL.

  14. Silicon detectors at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Brau, James E. [University of Oregon, Eugene, OR 97405-1274 (United States)], E-mail: jimbrau@uoregon.edu; Breidenbach, Martin [Stanford Linear Accelerator Center, Menlo Park, CA 94025 (United States); Baltay, Charles [Yale University, New Haven, CT 06520-8120 (United States); Frey, Raymond E.; Strom, David M. [University of Oregon, Eugene, OR 97405-1274 (United States)

    2007-09-01

    Silicon detectors are being developed for several applications in ILC detectors. These include vertex detection, tracking, electromagnetic calorimetry, and forward detectors. The advantages of silicon detector technology have been incorporated into a full detector design, SiD (the Silicon Detector). A brief overview of this effort is presented.

  15. Silicon quantum dots: surface matters

    NARCIS (Netherlands)

    Dohnalová, K.; Gregorkiewicz, T.; Kůsová, K.

    2014-01-01

    Silicon quantum dots (SiQDs) hold great promise for many future technologies. Silicon is already at the core of photovoltaics and microelectronics, and SiQDs are capable of efficient light emission and amplification. This is crucial for the development of the next technological frontiers—silicon

  16. Characterization of oxygen dimer-enriched silicon detectors

    CERN Document Server

    Boisvert, V; Moll, M; Murin, L I; Pintilie, I

    2005-01-01

    Various types of silicon material and silicon p+n diodes have been treated to increase the concentration of the oxygen dimer (O2i) defect. This was done by exposing the bulk material and the diodes to 6 MeV electrons at a temperature of about 350 °C. FTIR spectroscopy has been performed on the processed material confirming the formation of oxygen dimer defects in Czochralski silicon pieces. We also show results from TSC characterization on processed diodes. Finally, we investigated the influence of the dimer enrichment process on the depletion voltage of silicon diodes and performed 24 GeV/c proton irradiations to study the evolution of the macroscopic diode characteristics as a function of fluence.

  17. Evolution of silicon sensor technology in particle physics

    CERN Document Server

    Hartmann, Frank

    2017-01-01

    This informative monograph describes the technological evolution of silicon detectors and their impact on high energy particle physics. The author here marshals his own first-hand experience in the development and also the realization of the DELPHI, CDF II and the CMS tracking detector. The basic principles of small strip- and pixel-detectors are presented and also the final large-scale applications. The Evolution of Silicon Detector Technology acquaints readers with the manifold challenges involving the design of sensors and pushing this technology to the limits. The expert will find critical information that is so far only available in various slide presentation scattered over the world wide web. This practical introduction of silicon sensor technology and its day to day life in the lab also offers many examples to illustrate problems and their solutions over several detector generations. The new edition gives a detailed overview of the silicon sensor technology used at the LHC, from basic principles to act...

  18. Identifying Electronic Properties Relevant to Improving the Performance and Stability of Amorphous Silicon Based Mid-Gap and Low-Gap Cells: Final Subcontract Report, 16 January 1998-15 October 2001

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, J. D.

    2002-07-01

    This report describes our experimental studies which have been concentrated in roughly five areas. Specifically: (1) We have examined a?Si:H grown very close to the microcrystalline phase boundary, so-called''edge material,'' to help understand why such material is more stable with respect to light-induced degradation; (2) We have also studied the electronic properties, and degradation characteristics of mixed phase material that is mostly a?Si:H, but which contains a significant microcrystalline component; (3) We have examined the electronic properties of high deposition rate material. These studies have included both moderately high deposition rate material (up to 6/s) produced by the PECVD growth method, and extremely high deposition rate material (up to 130/s) produced by the HWCVD growth method. (4) We have examined series of a-Si,Ge:H alloys from several sources. In one extensive series of studies we examined low Ge fraction alloys in an attempt to learn more about the fundamentals of degradation in general. In a couple other studies we evaluated the properties of a-Si,Ge:H alloys produced by methods we had not previously examined. (5) Finally, for three different types of samples we compared basic material properties with companion cell performance data. This was carried out in each case on series of samples for which one or more specific deposition parameters were varied systematically.

  19. Silicon-Light: a European FP7 Project Aiming at High Efficiency Thin Film Silicon Solar Cells on Foil

    DEFF Research Database (Denmark)

    Soppe, W.; Haug, F.-J.; Couty, P.

    2011-01-01

    calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils......Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano...... with nanotexture is shown. Microcrystalline and amorphous silicon single junction cells with stable efficiencies with more than 8 % have been made, paving the way towards a-Si/ c-Si tandem cells with more than 11% efficiency....

  20. Synthesis of colloidal solutions with silicon nanocrystals from porous silicon.

    Science.gov (United States)

    Luna López, José Alberto; Garzón Román, Abel; Gómez Barojas, Estela; Gracia, Jf Flores; Martínez Juárez, Javier; Carrillo López, Jesús

    2014-01-01

    In this work, we have obtained colloidal solutions of Si nanocrystals (Si-ncs), starting from free-standing porous silicon (PSi) layers. PSi layers were synthesized using a two-electrode Teflon electrochemical cell; the etching solution contained hydrogen peroxide 30%, hydrofluoric acid 40% (HF), and methanol. The anodizing current density was varied to 250 mA cm(-2), 1 A cm(-2), and 1.2 A cm(-2). Thus obtained, PSi was mechanically pulverized in a mortar agate; then, the PSi powders were poured into different solutions to get the final Si-ncs colloidal solutions. The different optical, morphological, and structural characteristics of the colloidal solutions with Si-ncs were measured and studied. These Si-ncs colloidal solutions, measured by photoluminescence (PL), revealed efficient blue-green or violet emission intensities. The results of X-ray diffraction (XRD) indicate that the colloidal solutions are mainly composed of silicon nanocrystallites. The result of UV-vis transmittance indicates that the optical bandgap energies of the colloidal solutions varied from 2.3 to 3.5 eV for colloids prepared in methanol, ethanol, and acetone. The transmission electron microscopy (TEM) images showed the size of the nanocrystals in the colloidal solutions. Fourier transform infrared spectroscopy (FTIR) spectra showed different types of chemical bonds such as Si-O-Si, Si-CH2, and SiH x , as well as some kind of defects. 61.46Df.-a; 61.43.Gt; 61.05.cp; 78.55.-m; 81.15.Gh.

  1. A silicon carbide array for electrocorticography and peripheral nerve recording

    Science.gov (United States)

    Diaz-Botia, C. A.; Luna, L. E.; Neely, R. M.; Chamanzar, M.; Carraro, C.; Carmena, J. M.; Sabes, P. N.; Maboudian, R.; Maharbiz, M. M.

    2017-10-01

    Objective. Current neural probes have a limited device lifetime of a few years. Their common failure mode is the degradation of insulating films and/or the delamination of the conductor-insulator interfaces. We sought to develop a technology that does not suffer from such limitations and would be suitable for chronic applications with very long device lifetimes. Approach. We developed a fabrication method that integrates polycrystalline conductive silicon carbide with insulating silicon carbide. The technology employs amorphous silicon carbide as the insulator and conductive silicon carbide at the recording sites, resulting in a seamless transition between doped and amorphous regions of the same material, eliminating heterogeneous interfaces prone to delamination. Silicon carbide has outstanding chemical stability, is biocompatible, is an excellent molecular barrier and is compatible with standard microfabrication processes. Main results. We have fabricated silicon carbide electrode arrays using our novel fabrication method. We conducted in vivo experiments in which electrocorticography recordings from the primary visual cortex of a rat were obtained and were of similar quality to those of polymer based electrocorticography arrays. The silicon carbide electrode arrays were also used as a cuff electrode wrapped around the sciatic nerve of a rat to record the nerve response to electrical stimulation. Finally, we demonstrated the outstanding long term stability of our insulating silicon carbide films through accelerated aging tests. Significance. Clinical translation in neural engineering has been slowed in part due to the poor long term performance of current probes. Silicon carbide devices are a promising technology that may accelerate this transition by enabling truly chronic applications.

  2. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  3. Silicone/Acrylate Copolymers

    Science.gov (United States)

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

  4. On nanostructured silicon success

    DEFF Research Database (Denmark)

    Sigmund, Ole; Jensen, Jakob Søndergaard; Frandsen, Lars Hagedorn

    2016-01-01

    Recent Letters by Piggott et al. 1 and Shen et al. 2 claim the smallest ever dielectric wave length and polarization splitters. The associated News & Views article by Aydin3 states that these works “are the first experimental demonstration of on-chip, silicon photonic components based on complex ...

  5. DELPHI Silicon Tracker

    CERN Document Server

    DELPHI was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. The silicon tracking detector was nearest to the collision point in the centre of the detector. It was used to pinpoint the collision and catch short-lived particles.

  6. ALICE Silicon Pixel Detector

    CERN Multimedia

    Manzari, V

    2013-01-01

    The Silicon Pixel Detector (SPD) forms the innermost two layers of the 6-layer barrel Inner Tracking System (ITS). The SPD plays a key role in the determination of the position of the primary collision and in the reconstruction of the secondary vertices from particle decays.

  7. Silicon in cereal straw

    DEFF Research Database (Denmark)

    Murozuka, Emiko

    Silicon (Si) is known to be a beneficial element for plants. However, when plant residues are to be used as feedstock for second generation bioenergy, Si may reduce the suitability of the biomass for biochemical or thermal conversion technologies. The objective of this PhD study was to investigate...

  8. Electrometallurgy of Silicon

    Science.gov (United States)

    1988-01-01

    on record is that of St. Claire DeVille, who claimed that silicon was produced by electrolysing an impure melt of NaAlC14, but his material did not...this composition and purified melts were electrolysed at about 14500C in graphite crucible and using graphite electrodes. Applied potentials were

  9. OPAL Silicon Tungsten Luminometer

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. The Silicon Tungsten Luminometer was part of OPAL's calorimeter which was used to measure the energy of particles. Most particles end their journey in calorimeters. These detectors measure the energy deposited when particles are slowed down and stopped.

  10. Hybrid silicon ring lasers

    Science.gov (United States)

    Liang, Di; Fiorentino, Marco; Bowers, John E.; Beausoleil, Raymond G.

    2011-01-01

    Hybrid silicon platform provides a solution to integrate active components (lasers, amplifiers, photodetectors, etc.) with passive ones on the same silicon substrate, which can be used for building an optical interconnect system. Owing to the advantages in footprint, power consumption, and high-speed modulation, hybrid silicon microring lasers have been demonstrated as a potential candidate for on-chip silicon light source. In this paper we review the progress to improve the performance of recently demonstrated compact microring lasers with ring diameter of 50 μm. A simple approach to enhance optical mode and electron-hole recombination, which results in threshold reduction and efficiency improvement is developed. This is done by appropriately undercutting the multiple quantum well (MQW) region to force carriers to flow towards the outer edge of the microring for better gain/optical mode overlap. We observe a reduction of the threshold of over 20% and up to 80% output power enhancement. The model and the experimental results highlight the benefits, as well as the negative effects from excessive undercutting, including lower MQW confinement, higher modal loss and higher thermal impedance. A design rule for MQW undercutting is therefore provided. Application as on-chip optical interconnects is discussed from a system perspective.

  11. Modeling Raman scattering in porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Miguel [Seccion de Estudios de Posgrado, ESIME-Culhuacan, IPN, Av. Santa Ana 1000, 04430, Mexico, D.F. (Mexico); Wang, Chumin [Instituto de Investigaciones en Materiales, UNAM, A.P. 70-360, 04510, Mexico, D.F. (Mexico)

    2005-06-01

    In this work, we model the Raman scattering by phonons using the Born potential and the Green's function formalism, which takes into account the long-range correlation of atomic vibrations. The porous silicon is viewed as a sponge, in which periodical column pores are dug in direction [001] from crystalline silicon, i.e., a supercell model is used to calculate the Raman response. The results show that the main Raman peak shifts to lower energies when the porosity increases, and for square pores it asymptotically approaches to a limit value of 475 cm{sup -1}. Finally, the supercell results are compared with the quantum wire model, in which the main Raman peaks move to higher energies as the width of the wires grows. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Effect of controlled crucible movement on melting process and carbon contamination in Czochralski silicon crystal growth

    Science.gov (United States)

    Liu, Xin; Han, Xue-Feng; Nakano, Satoshi; Kakimoto, Koichi

    2018-02-01

    In Czochralski silicon (CZ-Si) crystal growth, packed Si chunks experience collapse and volume shrinkage during the melting process. The axial movements of the crucible and the melting of the Si feedstock lead to dynamic thermal and flow fields and affect mass transport. To study the effect of crucible movement on the melting process and carbon (C) contamination, the cases of fixed and lifting crucible were investigated by the transient global simulation with dynamic mesh deformation. The gap width between the gas-guide and the top surface of Si feedstock was kept constant during the crucible lifting process. Impurity and species transport in Si feedstock and argon gas was investigated for the cases with the fixed and lifting crucibles. The comparison of C accumulation processes indicated that the lifting crucible case resulted in higher C contamination than that found in the fixed crucible case. Furthermore, lifting crucible cases with different gap widths were investigated to elaborate strategies for controlling the crucible movement for its effect on the melting process and C contamination in CZ-Si crystal growth. It was observed that the optimum gap width for C reduction results from the trade-off between the back diffusion and gas convection.

  13. Silicon in beer and brewing.

    Science.gov (United States)

    Casey, Troy R; Bamforth, Charles W

    2010-04-15

    It has been claimed that beer is one of the richest sources of silicon in the diet; however, little is known of the relationship between silicon content and beer style and the manner in which beer is produced. The purpose of this study was to measure silicon in a diversity of beers and ascertain the grist selection and brewing factors that impact the level of silicon obtained in beer. Commercial beers ranged from 6.4 to 56.5 mg L(-1) in silicon. Products derived from a grist of barley tended to contain more silicon than did those from a wheat-based grist, likely because of the high levels of silica in the retained husk layer of barley. Hops contain substantially more silicon than does grain, but quantitatively hops make a much smaller contribution than malt to the production of beer and therefore relatively less silicon in beer derives from them. During brewing the vast majority of the silicon remains with the spent grains; however, aggressive treatment during wort production in the brewhouse leads to increased extraction of silicon into wort and much of this survives into beer. It is confirmed that beer is a very rich source of silicon. (c) 2010 Society of Chemical Industry.

  14. Formation of silicon nanoparticles from high temperature annealed silicon rich silicon oxynitride films

    Science.gov (United States)

    Slaoui, Abdelilah; Ehrhardt, Fabien; Delachat, Florian; Ferblantier, Gérald; Muller, Dominique

    2012-10-01

    Silicon rich silicon oxynitride layers were deposited by ECR-PECVD in order to form silicon nanoparticles upon high thermal annealing at 1100°C. The effect of the gas precursor type and flows on the atomic composition and the structural properties was assessed by RBS and ERDA analysis as well as by Raman spectroscopy. The morphological and crystalline properties of the resulting nanoparticles were investigated by TEM analysis. We have found that the silicon nanoparticules average size and the crystalline fraction depend strongly on the silicon excess in the SiN and SiON layer.

  15. Comparison between strong η-fiber-oriented high-silicon steel and grain-oriented high-silicon steel on magnetic properties

    Science.gov (United States)

    Qin, Jing; Yue, Ye; Zhang, Yinghui; Cao, Yanyan; Yang, Ping

    2017-10-01

    Two kinds of 0.23 mm-thick high-silicon steel sheets with strong η-fiber texture and Goss texture were produced by rolling methods. Their final microstructures, textures and magnetic properties were analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive spectroscopy (EDS), X-ray diffractometer (XRD), electron backscattered diffraction (EBSD) and classical loss separation. The results showed that the core loss of strong η-fiber-oriented high-silicon steel was lower than that of grain-oriented high-silicon steel at frequencies ranging from 40 Hz to 20 kHz, and their differences in core loss were more obvious at 400 Hz and higher frequencies. The hysteresis losses and anomalous losses of the strong η-fiber-oriented high-silicon steel were lower than that of grain-oriented high-silicon steel at frequencies ranging from 40 Hz to 1000 Hz, and the losses were closely related to final cleanness and grain sizes. A few stable remained nitride precipitates increased the hysteresis loss of the grain-oriented high-silicon steel. The effect of decreasing grain sizes on decreasing core losses at high frequencies was significant, and the strong η-fiber-oriented high-silicon steel was more suitable for high frequency applications because of smaller grain sizes compared to the grain-oriented high-silicon steel.

  16. Characterization and optimization of Silicon Photomultipliers and small size scintillator tiles for future calorimeter applications

    CERN Document Server

    AUTHOR|(CDS)2095312; Horváth, Ákos

    For the active layers of highly granular sampling calorimeters, small scintillator tiles read out by Silicon Photomultipliers (SiPM) can be an interesting and cost effective alternative to silicon sensors. At CERN a test setup was realized for the development of new generations of calorimeters to characterize new types of Silicon Photomultipliers in terms of gain, noise, afterpulses and crosstalk and to study the impact of scintillator wrappings and the tile size on the measured light yield and uniformity. In this thesis work, the experimental setup is described and the steps for commissioning the equipment are discussed. Then, the temperature dependence of the Silicon Photomultiplier response will be investigated, including the dependence of bare Silicon Photomultipliers as well as Silicon Photomultipliers coupled to scintillator tiles. Finally, the tile-photomultiplier response for different tile sizes and coating options will be evaluated. The experimental setup will be extended to allow for the characteri...

  17. Characterization of New-Generation Silicon Photomultipliers for Nuclear Security Applications

    Directory of Open Access Journals (Sweden)

    Wonders Marc A.

    2018-01-01

    Full Text Available Silicon photomultipliers have received a great deal of interest recently for use in applications spanning a wide variety of fields, including nuclear safeguards and nonproliferation. For nuclear-related applications, the ability of silicon photomultipliers to discriminate neutrons from gamma rays using pulse shape discrimination when coupled with certain organic scintillators is a characteristic of utmost importance. This work reports on progress characterizing the performance of twenty different silicon photomultipliers from five manufacturers with an emphasis on pulse shape discrimination performance and timing. Results are presented on pulse shape discrimination performance as a function of overvoltage for 6-mm x 6-mm silicon photomultipliers, and the time response to stilbene is characterized for silicon photomultipliers of three different sizes. Finally, comparison with a photomultiplier tube shows that some new-generation silicon photomultipliers can perform as well as photomultiplier tubes in neutron-gamma ray discrimination.

  18. p-Type Quasi-Mono Silicon Solar Cell Fabricated by Ion Implantation

    Directory of Open Access Journals (Sweden)

    Chien-Ming Lee

    2013-01-01

    Full Text Available The p-type quasi-mono wafer is a novel type of silicon material that is processed using a seed directional solidification technique. This material is a promising alternative to traditional high-cost Czochralski (CZ and float-zone (FZ material. Here, we evaluate the application of an advanced solar cell process featuring a novel method of ion implantation on p-type quasi-mono silicon wafer. The ion implantation process has simplified the normal industrial process flow by eliminating two process steps: the removal of phosphosilicate glass (PSG and the junction isolation process that is required after the conventional thermal POCl3 diffusion process. Moreover, the good passivation performance of the ion implantation process improves Voc. Our results show that, after metallization and cofiring, an average cell efficiency of 18.55% can be achieved using 156 × 156 mm p-type quasi-mono silicon wafer. Furthermore, the absolute cell efficiency obtained using this method is 0.47% higher than that for the traditional POCl3 diffusion process.

  19. Accelerated light-induced degradation for detecting copper contamination in p-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Inglese, Alessandro, E-mail: alessandro.inglese@aalto.fi; Savin, Hele [Department of Micro- and Nanosciences, Aalto University, Tietotie 3, 02150 Espoo (Finland); Lindroos, Jeanette [Department of Micro- and Nanosciences, Aalto University, Tietotie 3, 02150 Espoo (Finland); Department of Engineering and Physics, Karlstad University, Universitetsg. 2, 65188 Karlstad (Sweden)

    2015-08-03

    Copper is a harmful metal impurity that significantly impacts the performance of silicon-based devices if present in active regions. In this contribution, we propose a fast method consisting of simultaneous illumination and annealing for the detection of copper contamination in p-type silicon. Our results show that, within minutes, such method is capable of producing a significant reduction of the minority carrier lifetime. A spatial distribution map of copper contamination can then be obtained through the lifetime values measured before and after degradation. In order to separate the effect of the light-activated copper defects from the other metastable complexes in low resistivity Cz-silicon, we carried out a dark anneal at 200 °C, which is known to fully recover the boron-oxygen defect. Similar to the boron-oxygen behavior, we show that the dark anneal also recovers the copper defects. However, the recovery is only partial and it can be used to identify the possible presence of copper contamination.

  20. Room-temperature near-infrared electroluminescence from boron-diffused silicon pn junction diodes

    Directory of Open Access Journals (Sweden)

    Si eLi

    2015-02-01

    Full Text Available Silicon pn junction diodes with different doping concentrations were prepared by boron diffusion into Czochralski (CZ n-type silicon substrate. Their room-temperature near-infrared electroluminescence (EL was measured. In the EL spectra of the heavily boron doped diode, a luminescence peak at ~1.6 m (0.78 eV was observed besides the band-to-band line (~1.1eV under the condition of high current injection, while in that of the lightly boron doped diode only the band-to-band line was observed. The intensity of peak at 0.78 eV increases exponentially with current injection with no observable saturation at room temperature. Furthermore, no dislocations were found in the cross-sectional transmission electron microscopy image, and no dislocation-related luminescence was observed in the low-temperature photoluminescence spectra. We deduce the 0.78 eV emission originates from the irradiative recombination in the strain region of diodes caused by the diffusion of large number of boron atoms into silicon crystal lattice.

  1. The tourism resources and possibilities using of its for development of the town and commune of Nałęczów and the commune of Wojciechów

    Science.gov (United States)

    Świeca, Andrzej; Brzezińska-Wójcik, Teresa

    2009-01-01

    Structural part of the resources of the tourism potential of the town and commune of Nałęczów and the commune of Wojciechów was studied in this paper. In the study, the attractiveness of tourism resources of the communes was assessed based on 48 features grouped into four divisions: sightseeing assets, recreational and special assets, tourist infrastructure and environmental protection. A field survey (listing, query) and a quantitative evaluation of tourist resources, carried out by means of a multidimensional comparative analysis, indicated an appreciable difference in features between the commune of Nałęczów and commune of Wojciechów. The tourist attractiveness index determined for the commune of Nałęczów was 0.695, almost twice as high as the index for the commune of Wojciechów (0.349). In the light of carrying out of investigations, the tourist attractiveness of the commune of Nałęczów results primarily from its environmental (mineral springs, unique flora) and cultural assets (historic monuments) as well as recreational assets (bioclimate, forest complexes, ravines; more than half of the commune's territory is within the Kazimierz Landscape Park) and special assets (angling). The tourism potential of the commune of Wojciechów is primarily determined by its recreational assets (diverse land relief) and special assets (hunting). The commune of Nałęczów is superior with regard to tourist infrastructure and environmental protection. Owing to the diversity of tourist assets, different degrees of tourist infrastructure development and varying quality of the natural environment, various forms of tourism exist in the two communes, i.e. educational tourism (environmental, geotourism, ecotourism, cultural and festival tourism), recreational tourism (agritourism), adventure tourism (walking, cycling, skiing and cross-country skiing) as well as health tourism (health, spa and wellness tourism).

  2. Non ideal dark I-V curves behavior of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, A.; Marchand, J.J.; Laugier, A. [Institut National des Sciences Appliquees, Laboratoire de Physique de la Matiere-UMR no. 5511, Villeurbanne (France)

    1998-02-27

    Dark I-V experiments have been performed on directional solidification (DS), Czochralsky (CZ) and cold crucible casting (CCC) silicon solar cells. Series and shunt resistances, ideality factors and saturation currents have been determined. However, the usual equations (recombination and diffusion current) cannot fit some cells, maybe because they are too approximated or because other mechanisms are present. The aim of this work is to explain the mechanisms occurring in these cells and to correlate them with the device characteristics. We show that for some solar cells we must add to the usual two-exponential model (diffusion and recombination), trap-assisted tunneling current and field-assisted recombination. The influence of the material on these currents has also been investigated

  3. Porous-like structures prepared by temperature-pressure treatment of heavily hydrogenated silicon

    Energy Technology Data Exchange (ETDEWEB)

    Misiuk, A. [Institute of Electron Technology, Al. Lotnikow 46, 02-668 Warsaw (Poland); Shalimov, A.; Bak-Misiuk, J. [Institute of Physics, PAS, Al. Lotnikow 32, 02-668 Warsaw (Poland); Surma, B. [Institute of Electron Technology, Al. Lotnikow 46, 02-668 Warsaw (Poland); Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Wnuk, A. [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Antonova, I.V. [Institute of Semiconductor Physics, SB RAS, Lavrentieva 13, 630090 Novosibirsk (Russian Federation); Zavodinsky, V.G.; Gnidenko, A.A. [Institute of Materials Science, RAS, Tikhookeanskaya 153, 680042 Khabarovsk (Russian Federation)

    2005-06-01

    Microstructure and related properties of Czochralski silicon heavily doped with hydrogen by implantation (hydrogen dose 2.7 x 10{sup 17} cm{sup -2}, at 24 keV) or by hydrogen plasma etching (reference samples) and treated at up to 1270 K (HT) under argon pressure up to 1.1 GPa (HP) are investigated. The structure of HT-HP treated Cz-Si:H is similar to that of porous (spongy) Si. Visible photoluminescence at 2.0-2.8 eV originates from accumulation of hydrogen and oxygen atoms near the sample surface. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Naturally occurring 32 Si and low-background silicon dark matter detectors

    Energy Technology Data Exchange (ETDEWEB)

    Orrell, John L.; Arnquist, Isaac J.; Bliss, Mary; Bunker, Raymond; Finch, Zachary S.

    2018-05-01

    The naturally occurring radioisotope Si-32 represents a potentially limiting background in future dark matter direct-detection experiments. We investigate sources of Si-32 and the vectors by which it comes to reside in silicon crystals used for fabrication of radiation detectors. We infer that the Si-32 concentration in commercial single-crystal silicon is likely variable, dependent upon the specific geologic and hydrologic history of the source (or sources) of silicon “ore” and the details of the silicon-refinement process. The silicon production industry is large, highly segmented by refining step, and multifaceted in terms of final product type, from which we conclude that production of Si-32-mitigated crystals requires both targeted silicon material selection and a dedicated refinement-through-crystal-production process. We review options for source material selection, including quartz from an underground source and silicon isotopically reduced in Si-32. To quantitatively evaluate the Si-32 content in silicon metal and precursor materials, we propose analytic methods employing chemical processing and radiometric measurements. Ultimately, it appears feasible to produce silicon-based detectors with low levels of Si-32, though significant assay method development is required to validate this claim and thereby enable a quality assurance program during an actual controlled silicon-detector production cycle.

  5. Understanding and mitigating the lid in SP Al-BSF Cz-Si solar cell by use of IR-belt furnace Rapid Thermal Processing

    Science.gov (United States)

    Mvutu, Mayangi Ma

    In this study, Rapid Thermal Processing was used to understand and mitigate the light-induced degradation in boron-doped Cz-Si solar cells. Two different design-types of solar cells were used in the experiment to investigate the impact the solar cell design (structure) might have in lifetime recovery. The two design types include 5-Busbar (5BB) and 4-Street-5-Busbar (4S-5BB), with a resistivity of 2 O-cm, surface area of 239 cm2, thickness of 0.018 cm, and doping concentration of 7.22 x 10 15 cm-3. In the annealing process, the peak temperature of 795°C, belt speed of 210 ipm, and dwell time of less than 2 minutes were used. It was found that solar cell design-type does not affect the lifetime recovery, since both design-types showed similar trends in all electrical output parameters. Also, although the lifetime was fully recovered following the annealing, the efficiency was not, because of contact degradation that resulted in high series resistance and junction recombination. Thus contact firing is key to effective lifetime and efficiency recovery.

  6. Reduction of the environmental impacts in crystalline silicon module manufacturing

    NARCIS (Netherlands)

    Alsema, E.A.|info:eu-repo/dai/nl/073416258; de Wild-Schoten, M.J.

    2007-01-01

    In this paper we review the most important options to reduce environmental impacts of crystalline silicon modules. We investigate which are the main barriers for implementation of the measure. Finally we review which measures to reduce environmental impacts could also lead to a cost reduction.

  7. Surface chemistry of a hydrogenated mesoporous p-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Media, El-Mahdi, E-mail: belhadidz@tahoo.fr; Outemzabet, Ratiba, E-mail: oratiba@hotmail.com

    2017-02-15

    Highlights: • Due to its large specific surface porous silicon is used as substrate for drug therapy and biosensors. • We highlight the evidency of the contribution of the hydrides (SiHx) in the formation of the porous silicon. • The responsible species in the porous silicon formation are identified and quantified at different conditions. • By some chemical treatments we show that silicon surface can be turn from hydrophobic to hydrophilic. - Abstract: The finality of this work is devoted to the grafting of organic molecules on hydrogen passivated mesoporous silicon surfaces. The study would aid in the development for the formation of organic monolayers on silicon surface to be exploited for different applications such as the realisation of biosensors and medical devices. The basic material is silicon which has been first investigated by FTIR at atomistic plane during the anodic forward and backward polarization (i.e. “go” and “return”). For this study, we applied a numerical program based on least squares method to infrared absorbance spectra obtained by an in situ attenuated total reflection on p-type silicon in diluted HF electrolyte. Our numerical treatment is based on the fitting of the different bands of IR absorbance into Gaussians corresponding to the different modes of vibration of molecular groups such as siloxanes and hydrides. An adjustment of these absorbance bands is done systematically. The areas under the fitted bands permit one to follow the intensity of the different modes of vibration that exist during the anodic forward and backward polarization in order to compare the reversibility of the phenomenon of the anodic dissolution of silicon. It permits also to follow the evolution between the hydrogen silicon termination at forward and backward scanning applied potential. Finally a comparison between the states of the initial and final surface was carried out. We confirm the presence of clearly four and three distinct vibration modes

  8. Recent advances in silicon photonic integrated circuits

    Science.gov (United States)

    Bowers, John E.; Komljenovic, Tin; Davenport, Michael; Hulme, Jared; Liu, Alan Y.; Santis, Christos T.; Spott, Alexander; Srinivasan, Sudharsanan; Stanton, Eric J.; Zhang, Chong

    2016-02-01

    We review recent breakthroughs in silicon photonics technology and components and describe progress in silicon photonic integrated circuits. Heterogeneous silicon photonics has recently demonstrated performance that significantly outperforms native III-V components. The impact active silicon photonic integrated circuits could have on interconnects, telecommunications, sensors and silicon electronics is reviewed.

  9. The processing and potential applications of porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Shieh, Syyuan [Univ. of California, Berkeley, CA (United States)

    1992-07-01

    Stability of a cylindrical pore under the influence of surface energy is important for porous silicon (PS) processing in the integrated circuit industry. Once the zig-zag cylindrical pores of porous silicon or oxidized porous silicon (OPS) are unstable and breakup into rows of isolated spherical pores, oxidation of PS and densification/nitridation of OPS become difficult. Swing to difficulty transport of reactant gas (O2, NH3) or the trapped gas (for densification of OPS). A first order analysis of the stability of a cylindrical pore or cylinder is considered first. Growth of small sinusoidal perturbations by viscous flow or evaporation/condensation result in dependence of perturbation growth rate on perturbation wavelength. Rapid thermal oxidation (RTO) of porous silicon is proposed as an alternative for the tedious two-step 300 and 800C oxidation process. Transmission electron microscopy, energy dispersive spectroscopy ESCA are used for quality control. Also, rapid thermal nitridation of oxidized porous silicon in ammonia is proposed to enhance OPS resistance to HF solution. Pores breakup of OPS results in a trapped gas problem during densification. Wet helium is proposed as OPS densification ambient gas to shorten densification time. Finally, PS is proposed to be an extrinsic gettering center in silicon wafers. The suppression of oxidation-induced stacking faults is used to demonstrate the gettering ability. Possible mechanism is discussed.

  10. The processing and potential applications of porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Syyuan Shieh.

    1992-07-01

    Stability of a cylindrical pore under the influence of surface energy is important for porous silicon (PS) processing in the integrated circuit industry. Once the zig-zag cylindrical pores of porous silicon or oxidized porous silicon (OPS) are unstable and breakup into rows of isolated spherical pores, oxidation of PS and densification/nitridation of OPS become difficult. Swing to difficulty transport of reactant gas (O{sub 2}, NH{sub 3}) or the trapped gas (for densification of OPS). A first order analysis of the stability of a cylindrical pore or cylinder is considered first. Growth of small sinusoidal perturbations by viscous flow or evaporation/condensation result in dependence of perturbation growth rate on perturbation wavelength. Rapid thermal oxidation (RTO) of porous silicon is proposed as an alternative for the tedious two-step 300 and 800C oxidation process. Transmission electron microscopy, energy dispersive spectroscopy ESCA are used for quality control. Also, rapid thermal nitridation of oxidized porous silicon in ammonia is proposed to enhance OPS resistance to HF solution. Pores breakup of OPS results in a trapped gas problem during densification. Wet helium is proposed as OPS densification ambient gas to shorten densification time. Finally, PS is proposed to be an extrinsic gettering center in silicon wafers. The suppression of oxidation-induced stacking faults is used to demonstrate the gettering ability. Possible mechanism is discussed.

  11. Silicon germanium as a novel mask for silicon deep reactive ion etching

    KAUST Repository

    Serry, Mohamed Y.

    2013-10-01

    This paper reports on the use of p-type polycrystalline silicon germanium (poly-Si1-xGex) thin films as a new masking material for the cryogenic deep reactive ion etching (DRIE) of silicon. We investigated the etching behavior of various poly-Si1-xGex:B (0silicon, silicon oxide, and photoresist was determined at different etching temperatures, ICP and RF powers, and SF6 to O2 ratios. The study demonstrates that the etching selectivity of the SiGe mask for silicon depends strongly on three factors: Ge content; boron concentration; and etching temperature. Compared to conventional SiO2 and SiN masks, the proposed SiGe masking material exhibited several advantages, including high etching selectivity to silicon (>1:800). Furthermore, the SiGe mask was etched in SF6/O2 plasma at temperatures ≥ - 80°C and at rates exceeding 8 μm/min (i.e., more than 37 times faster than SiO2 or SiN masks). Because of the chemical and thermodynamic stability of the SiGe film as well as the electronic properties of the mask, it was possible to deposit the proposed film at CMOS backend compatible temperatures. The paper also confirms that the mask can easily be dry-removed after the process with high etching-rate by controlling the ICP and RF power and the SF6 to O2 ratios, and without affecting the underlying silicon substrate. Using low ICP and RF power, elevated temperatures (i.e., > - 80°C), and an adjusted O2:SF6 ratio (i.e., ~6%), we were able to etch away the SiGe mask without adversely affecting the final profile. Ultimately, we were able to develop deep silicon- trenches with high aspect ratio etching straight profiles. © 1992-2012 IEEE.

  12. Silicon oxidation by ozone

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Christian K; Jenkins, Stephen J [Department of Chemistry, University of Cambridge, Cambridge CB2 1EW (United Kingdom); Nakamura, Ken; Ichimura, Shingo [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)], E-mail: sjj24@cam.ac.uk

    2009-05-06

    Understanding the oxidation of silicon has been an ongoing challenge for many decades. Ozone has recently received considerable attention as an alternative oxidant in the low temperature, damage-free oxidation of silicon. The ozone-grown oxide was also found to exhibit improved interface and electrical characteristics over a conventionally dioxygen-grown oxide. In this review article, we summarize the key findings about this alternative oxidation process. We discuss the different methods of O{sub 3} generation, and the advantages of the ozone-grown Si/SiO{sub 2} interface. An understanding of the growth characteristics is of utmost importance for obtaining control over this alternative oxidation process. (topical review)

  13. Silicon Carbide Electronic Devices

    Science.gov (United States)

    Neudeck, P. G.

    2001-01-01

    The status of emerging silicon carbide (SiC) widebandgap semiconductor electronics technology is briefly surveyed. SiC-based electronic devices and circuits are being developed for use in high-temperature, high-power, and/or high-radiation conditions under which conventional semiconductors cannot function. Projected performance benefits of SiC electronics are briefly illustrated for several applications. However, most of these operational benefits of SiC have yet to be realized in actual systems, primarily owing to the fact that the growth techniques of SiC crystals are relatively immature and device fabrication technologies are not yet sufficiently developed to the degree required for widespread, reliable commercial use. Key crystal growth and device fabrication issues that limit the performance and capability of high-temperature and/or high-power SiC electronics are identified. The electrical and material quality differences between emerging SiC and mature silicon electronics technology are highlighted.

  14. Germanium epitaxy on silicon

    Directory of Open Access Journals (Sweden)

    Hui Ye

    2014-03-01

    Full Text Available With the rapid development of on-chip optical interconnects and optical computing in the past decade, silicon-based integrated devices for monolithic and hybrid optoelectronic integration have attracted wide attention. Due to its narrow pseudo-direct gap behavior and compatibility with Si technology, epitaxial Ge-on-Si has become a significant material for optoelectronic device applications. In this paper, we describe recent research progress on heteroepitaxy of Ge flat films and self-assembled Ge quantum dots on Si. For film growth, methods of strain modification and lattice mismatch relief are summarized, while for dot growth, key process parameters and their effects on the dot density, dot morphology and dot position are reviewed. The results indicate that epitaxial Ge-on-Si materials will play a bigger role in silicon photonics.

  15. Silicone breast implants: complications.

    Science.gov (United States)

    Iwuagwu, F C; Frame, J D

    1997-12-01

    Silicone breast implants have been used for augmentation mammoplasty for cosmetic purposes as well as for breast reconstruction following mastectomy for more than three decades. Though the use of the silicone gel filled variety has been banned in the USA except for special cases, they continue to be available elsewhere in the world including the UK. Despite the immense benefit they provide, their usage is associated with some complications. Most of these are related to the surgery and can be reduced by good surgical management. The major complications associated with their use is adverse capsular contracture, an outcome which can be very frustrating to manage. This article reviews the commonly reported complications and suggested management alternatives.

  16. Silicon nanowire transistors

    CERN Document Server

    Bindal, Ahmet

    2016-01-01

    This book describes the n and p-channel Silicon Nanowire Transistor (SNT) designs with single and dual-work functions, emphasizing low static and dynamic power consumption. The authors describe a process flow for fabrication and generate SPICE models for building various digital and analog circuits. These include an SRAM, a baseband spread spectrum transmitter, a neuron cell and a Field Programmable Gate Array (FPGA) platform in the digital domain, as well as high bandwidth single-stage and operational amplifiers, RF communication circuits in the analog domain, in order to show this technology’s true potential for the next generation VLSI. Describes Silicon Nanowire (SNW) Transistors, as vertically constructed MOS n and p-channel transistors, with low static and dynamic power consumption and small layout footprint; Targets System-on-Chip (SoC) design, supporting very high transistor count (ULSI), minimal power consumption requiring inexpensive substrates for packaging; Enables fabrication of different types...

  17. Processing technology for high efficiency silicon solar cells

    Science.gov (United States)

    Spitzer, M. B.; Keavney, C. J.

    1985-01-01

    Recent advances in silicon solar cell processing have led to attainment of conversion efficiency approaching 20%. The basic cell design is investigated and features of greatest importance to achievement of 20% efficiency are indicated. Experiments to separately optimize high efficiency design features in test structures are discussed. The integration of these features in a high efficiency cell is examined. Ion implantation has been used to achieve optimal concentrations of emitter dopant and junction depth. The optimization reflects the trade-off between high sheet conductivity, necessary for high fill factor, and heavy doping effects, which must be minimized for high open circuit voltage. A second important aspect of the design experiments is the development of a passivation process to minimize front surface recombination velocity. The manner in which a thin SiO2 layer may be used for this purpose is indicated without increasing reflection losses, if the antireflection coating is properly designed. Details are presented of processing intended to reduce recombination at the contact/Si interface. Data on cell performance (including CZ and ribbon) and analysis of loss mechanisms are also presented.

  18. Electrons in silicon microstructures.

    Science.gov (United States)

    Howard, R E; Jackel, L D; Mankiewich, P M; Skocpol, W J

    1986-01-24

    Silicon microstructures only a few hundred atoms wide can be fabricated and used to study electron transport in narrow channels. Spatially localized voltage probes as close together as 0.1 micrometer can be used to investigate a variety of physical phenomena, including velocity saturation due to phonon emission, the local potentials caused by scattering from a single trapped electron, and quantum tunneling or hopping among very few electron states.

  19. Bringing Silicon Valley inside.

    Science.gov (United States)

    Hamel, G

    1999-01-01

    In 1998, Silicon Valley companies produced 41 IPOs, which by January 1999 had a combined market capitalization of $27 billion--that works out to $54,000 in new wealth creation per worker in a single year. Multiply the number of employees in your company by $54,000. Did your business create that much new wealth last year? Half that amount? It's not a group of geniuses generating such riches. It's a business model. In Silicon Valley, ideas, capital, and talent circulate freely, gathering into whatever combinations are most likely to generate innovation and wealth. Unlike most traditional companies, which spend their energy in resource allocation--a system designed to avoid failure--the Valley operates through resource attraction--a system that nurtures innovation. In a traditional company, people with innovative ideas must go hat in hand to the guardians of the old ideas for funding and for staff. But in Silicon Valley, a slew of venture capitalists vie to attract the best new ideas, infusing relatively small amounts of capital into a portfolio of ventures. And talent is free to go to the companies offering the most exhilarating work and the greatest potential rewards. It should actually be easier for large, traditional companies to set up similar markets for capital, ideas, and talent internally. After all, big companies often already have extensive capital, marketing, and distribution resources, and a first crack at the talent in their own ranks. And some of them are doing it. The choice is yours--you can do your best to make sure you never put a dollar of capital at risk, or you can tap into the kind of wealth that's being created every day in Silicon Valley.

  20. Structure of Silicon Clusters

    OpenAIRE

    Pan, Jun; Bahel, Atul; Ramakrishna, Mushti V.

    1995-01-01

    We determined the structures of silicon clusters in the 11-14 atom size range using the tight-binding molecular dynamics method. These calculations reveal that \\Si{11} is an icosahedron with one missing cap, \\Si{12} is a complete icosahedron, \\Si{13} is a surface capped icosahedron, and \\Si{14} is a 4-4-4 layer structure with two caps. The characteristic feature of these clusters is that they are all surface.

  1. Dynamic Silicon Nanophotonics

    Science.gov (United States)

    2013-07-31

    the waveguide. Furthermore, the design is fabricated using standard contact’s/via’s in a CMOS process (i.e. that traditionally connect metal layers to...process steps or even materials. It directly makes use of the standard metal contacts/via’s used to connect upper Metal layers to the active Silicon...Low-Voltage Lithium Niobate Electro-Optic Modulator,” In Preparation PERSONNEL SUPPORTED The following personnel have been supported by the YIP

  2. 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...

  3. Silicon photonics fundamentals and devices

    CERN Document Server

    Deen, M Jamal

    2012-01-01

    The creation of affordable high speed optical communications using standard semiconductor manufacturing technology is a principal aim of silicon photonics research. This would involve replacing copper connections with optical fibres or waveguides, and electrons with photons. With applications such as telecommunications and information processing, light detection, spectroscopy, holography and robotics, silicon photonics has the potential to revolutionise electronic-only systems. Providing an overview of the physics, technology and device operation of photonic devices using exclusively silicon and related alloys, the book includes: * Basic Properties of Silicon * Quantum Wells, Wires, Dots and Superlattices * Absorption Processes in Semiconductors * Light Emitters in Silicon * Photodetectors , Photodiodes and Phototransistors * Raman Lasers including Raman Scattering * Guided Lightwaves * Planar Waveguide Devices * Fabrication Techniques and Material Systems Silicon Photonics: Fundamentals and Devices outlines ...

  4. Annihilation of low energy antiprotons in silicon

    CERN Document Server

    Aghion, S; Belov, A S; Bonomi, G; Bräunig, P; Bremer, J; Brusa, R S; Burghart, G; Cabaret, L; Caccia, M; Canali, C; Caravita, R; Castelli, F; Cerchiari, G; Cialdi, S; Comparat, D; Consolati, G; Derking, J H; Di Domizio, S; Di Noto, L; Doser, M; Dudarev, A; Ferragut, R; Fontana, A; Genova, P; Giammarchi, M; Gligorova, A; Gninenko, S N; Haider, S; Harasimovic, J; Huse, T; Jordan, E; Jørgensen, L V; Kaltenbacher, T; Kellerbauer, A; Knecht, A; Krasnický, D; Lagomarsino, V; Magnani, A; Mariazzi, S; Matveev, V A; Moia, F; Nebbia, G; Nédélec, P; Pacifico, N; Petrácek, V; Prelz, F; Prevedelli, M; Regenfus, C; Riccardi, C; Røhne, O; Rotondi, A; Sandaker, H; Susa, A; Vasquez, M A Subieta; Špacek, M; Testera, G; Welsch, C P; Zavatarelli, S

    2013-01-01

    The goal of the AE$\\mathrm{\\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\\mathrm{\\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$%$ precision on the measurement of $\\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\\mathrm{\\bar{g}}$IS experiment. We also pr...

  5. Epitaxial Silicon Doped With Antimony

    Science.gov (United States)

    Huffman, James E.; Halleck, Bradley L.

    1996-01-01

    High-purity epitaxial silicon doped with antimony made by chemical vapor deposition, using antimony pentachloride (SbCI5) as source of dopant and SiH4, SiCI2H2, or another conventional source of silicon. High purity achieved in layers of arbitrary thickness. Epitaxial silicon doped with antimony needed to fabricate impurity-band-conduction photodetectors operating at wavelengths from 2.5 to 40 micrometers.

  6. Radiation hardening of silicon detectors

    CERN Document Server

    Lemeilleur, F

    1999-01-01

    The radiation hardness of high grade silicon detectors is summarized in terms of an increase of the diode reverse current and evolution of the full depletion voltage and charge collection efficiency. With the aim of improving their radiation tolerance, detectors have been produced from non-standard, float-zone silicon containing various atomic impurities and from epitaxial silicon materials. Some recent results concerning their radiation hardness are presented. (15 refs).

  7. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gurney, Kevin R. [Arizona Univ., Mesa, AZ (United States)

    2015-01-12

    This document constitutes the final report under DOE grant DE-FG-08ER64649. The organization of this document is as follows: first, I will review the original scope of the proposed research. Second, I will present the current draft of a paper nearing submission to Nature Climate Change on the initial results of this funded effort. Finally, I will present the last phase of the research under this grant which has supported a Ph.D. student. To that end, I will present the graduate student’s proposed research, a portion of which is completed and reflected in the paper nearing submission. This final work phase will be completed in the next 12 months. This final workphase will likely result in 1-2 additional publications and we consider the results (as exemplified by the current paper) high quality. The continuing results will acknowledge the funding provided by DOE grant DE-FG-08ER64649.

  8. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    DeTar, Carleton [P.I.

    2012-12-10

    This document constitutes the Final Report for award DE-FC02-06ER41446 as required by the Office of Science. It summarizes accomplishments and provides copies of scientific publications with significant contribution from this award.

  9. Silicon processing for photovoltaics II

    CERN Document Server

    Khattak, CP

    2012-01-01

    The processing of semiconductor silicon for manufacturing low cost photovoltaic products has been a field of increasing activity over the past decade and a number of papers have been published in the technical literature. This volume presents comprehensive, in-depth reviews on some of the key technologies developed for processing silicon for photovoltaic applications. It is complementary to Volume 5 in this series and together they provide the only collection of reviews in silicon photovoltaics available.The volume contains papers on: the effect of introducing grain boundaries in silicon; the

  10. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it ... options Linkedin Pin it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell ...

  11. Role of water in the tribochemical removal of bare silicon

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Cheng; Xiao, Chen [Tribology Research Institute, National Traction Power Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); Wang, Xiaodong [Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang 212013 (China); Zhang, Peng; Chen, Lei; Qi, Yaqiong [Tribology Research Institute, National Traction Power Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); Qian, Linmao, E-mail: linmao@swjtu.edu.cn [Tribology Research Institute, National Traction Power Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)

    2016-12-30

    Highlights: • The wear of bare silicon against SiO{sub 2} micro-spherical tip is a tribochemical process with participation of water. • The water amount at Si/SiO{sub 2} interface plays a significant role on the wear of bare silicon. • The role of water relies on the hydroxylation by auto-ionized OH{sup −}, the hydrolysis of H{sub 2}O molecules, and the dissolution of SiO{sub m}H{sub n} in water. - Abstract: Nanowear tests of bare silicon against a SiO{sub 2} microsphere were conducted in air (relative humidity [RH] = 0%–89%) and water using an atomic force microscope. Experimental results revealed that the water played an important role in the tribochemical wear of the bare silicon. A hillock-like wear trace with a height of 0.7 nm was generated on the bare silicon surface in dry air. As the RH increased, the wear depth increased and reached the maximum level in water. Analysis of frictional dissipated energy suggested that the wear of the bare silicon was not dominated by mechanical interactions. High-resolution transmission electron microscopy detection demonstrated that the silicon atoms and crystal lattice underneath the worn area maintained integral perfectly and thus further confirmed the tribochemical wear mechanism of the bare silicon. Finally, the role of water in the tribochemical wear of the bare silicon may be explained by the following three aspects: the hydroxylation by hydroxyl ions auto-ionized in water, the hydrolytic reaction of water molecules, and the dissolution of the tribochemical product SiO{sub m}H{sub n} in liquid water. With increasing RH, a greater water amount would adsorb to the Si/SiO{sub 2} interface and induce a more serious tribochemical wear on the bare silicon surface. The results of this paper may provide further insight into the tribochemical removal mechanism of bare monocrystalline silicon and furnish the wider reaction cognition for chemical mechanical polishing.

  12. Silicone and Fluorosilicone Based Materials for Biomedical Applications

    Science.gov (United States)

    Palsule, Aniruddha S.

    coating that is covalently grafted on the silicone surface in the form of dense polymer brushes. The research also attempts to validate the use of sterilization of the implant with gamma irradiation by comprehensively reviewing the existing literature and then summarizing the effects of gamma irradiation on linear, cyclic and crosslinked silicones. We have predicted a model describing the effects of irradiation and supplemented that with data in the laboratory. Finally we have investigated the use of biological enzymes as alternate catalyst systems for the synthesis of silicone copolymers. We have demonstrated the use of the enzyme Lipase (CALB), as a catalyst for the synthesis of fluorosilicone copolymers containing ester and amide linkages.

  13. Wybrane aspekty wpływu asymetrii funkcjonalnej półkul mózgowych na funkcjonowanie poznawcze oraz emocjonalne człowieka

    Directory of Open Access Journals (Sweden)

    Magdalena Sabiniewicz

    2015-12-01

    Full Text Available Przez wiele lat asymetria półkul mózgowych rozpatrywana była jako wyraźny podział funkcjonalny. W tym dychotomicznym modelu badacze wiązali półkulę lewą wyłącznie z funkcjami werbalnymi, a prawą – ze zdolnościami niewerbalnymi. Podział ten jest jednak niewyczerpujący i zdecydowanie upraszcza tematykę specjalizacji półkul mózgowych. Najnowsze doniesienia wskazują na współpracę i zarazem pewną niezależność międzypółkulową w zakresie kontroli funkcjonowania człowieka. Ponadto podkreśla się, że różnice funkcjonalne istnieją, ale są znacznie subtelniejsze, niż zakładano na początku badań dotyczących tej tematyki. Aby ułatwić zrozumienie istoty asymetrii funkcjonalnej, stworzono modele, które wyjaśniały mechanizm specjalizacji półkulowej i odrębność stylów przetwarzania bodźców. Dane potwierdzające istnienie asymetrii funkcjonalnej półkul pochodzą m.in. z doniesień o jednostronnych uszkodzeniach mózgu, agenezji spoidła wielkiego, zabiegach komisurotomii czy hemisferektomii. Na tej podstawie dokonano analizy funkcjonowania kognitywnego i emocjonalnego pacjentów. Wykryto pewne prawidłowości dotyczące różnic i podobieństw w funkcjonowaniu półkul mózgowych w zakresie percepcji wzrokowej, funkcji werbalnych, praksji, uwagi, pamięci i uczenia się czy funkcji wykonawczych. Jeśli chodzi o lateralizację emocji w mózgu, pojawia się wiele sprzecznych doniesień. Potrzebne są dalsze, dobrze zaprojektowane badania, które pomogą zrozumieć, czy istnieje lateralizacja emocji w mózgu, a jeśli tak, to jakich aspektów funkcjonowania afektywnego ona dotyczy. Niniejsza praca przedstawia przegląd poglądów na wpływ asymetrii półkul mózgowych na funkcjonowanie poznawcze, emocjonalne i behawioralne człowieka.

  14. Miłosz’s Response to Brzozowski. On Człowiek wśród skorpionów... [Man among Scorpions...] and More

    Directory of Open Access Journals (Sweden)

    Sylwia Panek

    2012-01-01

    Full Text Available The aim of the author of the article is to investigate Miłosz’s relation to Stanisław Brzozowski. Proceeding from the interpretation of Miłosz’s Człowiek wśród skorpionów..., and diagnosing his personal motivation for turning to Brzozowski’s works in 1963, the author investigates the avenues of dialogue between Miłosz and Brzozowski, and their unsys­tematically expresses common points. The article, thus, presents various stages of influence of Brzozowski’s work and ideas on Miłosz: from the 1930s, when Miłosz was inspired by Brzozowski’s left-wing fanaticism, through the common opposition against anti-intellectualism and the Polish identity understood as a set of Romantic symbols and gestures, up to the fascination with Russian culture and Marxism. The deepest affinity of both authors seems to be the attitude of anthropocentrism, identified and exposed by Miłosz himself, and understood as hostility towards nature and belief in nature’s determinism, but also as a formula that gives coherence to the philosophical themes, found in both authors’ work, which are thought to be polarised and incompatible. In the conclusion, the author of the article states that positioning himself with reference to Brzozowski was, for Miłosz, a tool of self-creation, an attempt to control the reception and interpretation of his own work, and to place Miłosz in a separate and exceptional position, akin to the position of Brzozowski, the extraordinary and unrecognized philosopher and critic of Polish early modernism.

  15. Inżynierowany jedwab pajęczy: inteligentny biomateriał przyszłości. Część II

    Directory of Open Access Journals (Sweden)

    Katarzyna Kaźmierska

    2011-06-01

    Full Text Available Opracowanie i rozwój technologii produkcji inżynierowanego jedwabiu stworzyły realne możliwości jego praktycznych zastosowań. Rekombinowany inżynierowany pajęczy jedwab (IPJ stanowi substrat do produkcji różnych biomateriałów, takich jak: filmy, hydrożele, włókna, rusztowania, mikrokapsułki, mikro- i nanosfery. Wytwarzanie in vitro włókien odbywa się w sposób naśladujący warunki naturalnie panujące w gruczole przędnym pająka: w obecności jonów fosforanowych oraz sił ciągnących. Filmy otrzymywane są przez odparowanie rozpuszczalnika z roztworu jedwabiu, natomiast rezultatem odparowywania rozpuszczalnika w obecności porogenu są jedwabne rusztowania. Hydrożele powstają w wyniku polimeryzacji cząstek jedwabiu w roztworach o niskim pH. Polimer jedwabiu powstający na granicy niemieszających się faz wykorzystywany jest do otrzymywania mikrokapsułek. Najmniejsze z opisywanych form – jedwabne sfery powstają przez wysolenie białek jedwabiu jonami fosforanowymi. Cechami wspólnymi jedwabnych biomateriałów są biokompatybilność oraz biodegradowalność pozwalające na wykorzystanie ich w medycynie i farmacji, a strategia konstrukcji białek hybrydowych polegająca na nadaniu metodami inżynierii genetycznej pożądanej funkcji dalej rozszerza możliwości ich wykorzystania.

  16. Low level of genetic variation within Melica transsilvanica populations from the Kraków-Częstochowa Upland and the Pieniny Mts revealed by AFLPs analysis

    Directory of Open Access Journals (Sweden)

    Magdalena Szczepaniak

    2011-01-01

    Full Text Available Fragmented distribution, the breeding system and effects of genetic drift in small-size populations occurring at edge of the species range play an important role in shaping genetic diversity of such a species. Melica transsilvanica is a plant rare in the flora of Poland, where it reaches the northern limit of its continuous range. Amplified Fragment Length Polymorphism (AFLP DNA profiling method was applied to measure genetic diversity among and within populations of M. transsilvanica. Additionally, genetic relationships between M. transsilvanica and Melica ciliata, two closely related species, were explored. A total of 68 plants from 7 populations of M. transsilvanica and 24 plants from 2 populations of M. ciliata, collected in Poland and outside it, were analyzed. Using 294 AFLP fragments from 3 primer combinations, accessions were grouped into two major clusters associating with M. ciliata and M. transsilvanica, respectively. Further, two subclusters, corresponding to the samples collected from the Pieniny Mts and from the Kraków - Częstochowa Upland were clearly distinguished within the M. transsilvanica group. The hierarchical AMOVA exhibited significant genetic distinction between these geographic regions (60.89%, p < 0.001. The obtained results showed that the most genetic diversity resided between the populations of M. transsilvanica (86.03% while considerably lower genetic variation was found within the populations (13.97%, which is consistent with the results reported for self-plants. The low level of AFLP genetic variation of M. transsilvanica can be caused by the geographic isolation of populations, which preserves the dominant self-mating breeding system of the species. Individual populations of M. transsilvanica are characterized by isolated gene pools differing by a small number of loci.

  17. Production of the LHCb Silicon Tracker Readout Electronics

    CERN Document Server

    Vollhardt, Achim; Carron, Benjamin; Fauland, Peter; Frei, Raymond; Jimenez-Otero, S; Perrin, A; Tran, Minh Tâm; Van Hunen, Jeroen; Vervink, Kim; Agari, Michaela; Bauer, Christian; Blouw, Johan; Hofmann, Werner; Knöpfle, K T; Löchner, S; Schmelling, Michael; Schwingenheuer, Bernhard; Smale, Nigel; Adeva, Bernardo; Esperante, Daniel; Lois, Cristina; Vazquez, Pablo; Bernhard, Ralf Patrick; Bernet, Roland; Gassner, Johannes; Köstner, S; Lehner, Frank; Needham, Matthew; Steinkamp, Olaf; Straumann, Ulrich; Volyanskyy, Dmytro; Voss, Helge; Wenger, Andreas

    2005-01-01

    We give an overview on the status of production of the LHCb Silicon Tracker Electronics. Lessons learned together with industry in the preseries production of the Silicon Tracker Digitizer Boards were integrated into the design to optimize the production and assembly yield for the main batch of 700 Digitizer Boards. A report on the preseries readout module performance and on the testing procedures for the full production lot is given. In addition, a final proton irradiation test of a complete readout system has been performed, of which results will be presented.

  18. Energy Harvesting Using Screen Printed PZT on Silicon

    DEFF Research Database (Denmark)

    Lei, Anders

    thickness being two orders of magnitude smaller than the cantilever length and width, is accomplished using the high control and precision of the silicon processing technology. With extensive process development the issue of fragility is minimised, and fabrication yields exceeding 90% are routinely achieved....... The final fabrication process features a sequence with screen printing of the PZT thick film at an early stage and cantilever definition by etching at a later stage. Screen printing PZT on a full thickness silicon wafer enables efficient use of a high pressure treatment process with improved performance...

  19. Indentation fatigue in silicon nitride, alumina and silicon carbide ...

    Indian Academy of Sciences (India)

    Repeated indentation fatigue (RIF) experiments conducted on the same spot of different structural ceramics viz. a hot pressed silicon nitride (HPSN), sintered alumina of two different grain sizes viz. 1 m and 25 m, and a sintered silicon carbide (SSiC) are reported. The RIF experiments were conducted using a Vicker's ...

  20. Narrative Finality

    Directory of Open Access Journals (Sweden)

    Armine Kotin Mortimer

    1981-01-01

    Full Text Available The cloturai device of narration as salvation represents the lack of finality in three novels. In De Beauvoir's Tous les hommes sont mortels an immortal character turns his story to account, but the novel makes a mockery of the historical sense by which men define themselves. In the closing pages of Butor's La Modification , the hero plans to write a book to save himself. Through the thrice-considered portrayal of the Paris-Rome relationship, the ending shows the reader how to bring about closure, but this collective critique written by readers will always be a future book. Simon's La Bataille de Pharsale , the most radical attempt to destroy finality, is an infinite text. No new text can be written. This extreme of perversion guarantees bliss (jouissance . If the ending of De Beauvoir's novel transfers the burden of non-final world onto a new victim, Butor's non-finality lies in the deferral to a future writing, while Simon's writer is stuck in a writing loop, in which writing has become its own end and hence can have no end. The deconstructive and tragic form of contemporary novels proclaims the loss of belief in a finality inherent in the written text, to the profit of writing itself.

  1. Silicon on insulator with active buried regions

    Science.gov (United States)

    McCarthy, Anthony M.

    1996-01-01

    A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

  2. Formation of aligned silicon nanowire on silicon by electroless etching in HF solution

    Energy Technology Data Exchange (ETDEWEB)

    Megouda, N.; Douani, R. [Faculte des Sciences, Universite Mouloud Mammeri, Tizi-Ouzou (Algeria); Hadjersi, T., E-mail: hadjersi@yahoo.co [Unite de Developpement de la Technologie du Silicium (UDTS), 2, Bd. Frantz Fanon, B.P. 140 Alger-7 merveilles, Alger (Algeria); Boukherroub, R. [Institut de Recherche Interdisciplinaire (IRI, FRE 2963), Institut d' Electronique, de Microelectronique et de Nanotechnologie (IEMN, CNRS-8520), Cite Scientifique, Avenue Poincare-B.P. 60069, 59652 Villeneuve d' Ascq (France)

    2009-12-15

    It was demonstrated that the etching in HF-based aqueous solution containing AgNO{sub 3} and Na{sub 2}S{sub 2}O{sub 8} as oxidizing agents or by Au-assisted electroless etching in HF/H{sub 2}O{sub 2} solution at 50 deg. C yields films composed of aligned Si nanowire (SiNW). SiNW of diameters {approx}10 nm were formed. The morphology and the photoluminescence (PL) of the etched layer as a function of etching solution composition were studied. The SiNW layers formed on silicon were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and photoluminescence. It was demonstrated that the morphology and the photoluminescence of the etched layers strongly depends on the type of etching solution. Finally, a discussion on the formation process of the silicon nanowires is presented.

  3. The LHCb Silicon Tracker

    CERN Document Server

    Elsasser, Ch; Gallas Torreira, A; Pérez Trigo, A; Rodríguez Pérez, P; Bay, A; Blanc, F; Dupertuis, F; Haefeli, G; Komarov, I; Märki, R; Muster, B; Nakada, T; Schneider, O; Tobin, M; Tran, M T; Anderson, J; Bursche, A; Chiapolini, N; Saornil, S; Steiner, S; Steinkamp, O; Straumann, U; Vollhardt, A; Britsch, M; Schmelling, M; Voss, H; Okhrimenko, O; Pugatch, V

    2013-01-01

    The aim of the LHCb experiment is to study rare heavy quark decays and CP vio- lation with the high rate of beauty and charmed hadrons produced in $pp$ collisions at the LHC. The detector is designed as a single-arm forward spectrometer with excellent tracking and particle identification performance. The Silicon Tracker is a key part of the tracking system to measure the particle trajectories to high precision. This paper reports the performance as well as the results of the radiation damage monitoring based on leakage currents and on charge collection efficiency scans during the data taking in the LHC Run I.

  4. Edgeless silicon pad detectors

    Energy Technology Data Exchange (ETDEWEB)

    Perea Solano, B. [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: blanca.perea.solano@cern.ch; Abreu, M.C. [LIP and University of Algarve, 8000 Faro (Portugal); Avati, V. [CERN, CH-1211 Geneva 23 (Switzerland); Boccali, T. [INFN Sez. di Pisa and Scuola Normale Superiore, Pisa (Italy); Boccone, V. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Bozzo, M. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Capra, R. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Casagrande, L. [INFN Sez. di Roma 2 and Universita di Roma 2, Rome (Italy); Chen, W. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Eggert, K. [CERN, CH-1211 Geneva 23 (Switzerland); Heijne, E. [CERN, CH-1211 Geneva 23 (Switzerland); Klauke, S. [CERN, CH-1211 Geneva 23 (Switzerland); Li, Z. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Maeki, T. [Helsinki Institute of Physics, Helsinki (Finland); Mirabito, L. [CERN, CH-1211 Geneva 23 (Switzerland); Morelli, A. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Niinikoski, T.O. [CERN, CH-1211 Geneva 23 (Switzerland); Oljemark, F. [Helsinki Institute of Physics, Helsinki (Finland); Palmieri, V.G. [Helsinki Institute of Physics, Helsinki (Finland); Rato Mendes, P. [LIP and University of Algarve, 8000 Faro (Portugal); Rodrigues, S. [LIP and University of Algarve, 8000 Faro (Portugal); Siegrist, P. [CERN, CH-1211 Geneva 23 (Switzerland); Silvestris, L. [INFN Sez. Di Bari, Bari (Italy); Sousa, P. [LIP and University of Algarve, 8000 Faro (Portugal); Tapprogge, S. [Helsinki Institute of Physics, Helsinki (Finland); Trocme, B. [Institut de Physique Nucleaire, Villeurbanne (France)

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in 'edgeless' planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5{+-}8{sub stat.}.{+-}6{sub syst.}) {mu}m.

  5. Edgeless silicon pad detectors

    Science.gov (United States)

    Perea Solano, B.; Abreu, M. C.; Avati, V.; Boccali, T.; Boccone, V.; Bozzo, M.; Capra, R.; Casagrande, L.; Chen, W.; Eggert, K.; Heijne, E.; Klauke, S.; Li, Z.; Mäki, T.; Mirabito, L.; Morelli, A.; Niinikoski, T. O.; Oljemark, F.; Palmieri, V. G.; Rato Mendes, P.; Rodrigues, S.; Siegrist, P.; Silvestris, L.; Sousa, P.; Tapprogge, S.; Trocmé, B.

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in "edgeless" planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5±8 stat..±6 syst.) μm.

  6. Impurity doping processes in silicon

    CERN Document Server

    Wang, FFY

    1981-01-01

    This book introduces to non-experts several important processes of impurity doping in silicon and goes on to discuss the methods of determination of the concentration of dopants in silicon. The conventional method used is the discussion process, but, since it has been sufficiently covered in many texts, this work describes the double-diffusion method.

  7. Development of an In-Line Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells: Annual Subcontract Report, June 2003 (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R. A.

    2004-04-01

    Under the PV Manufacturing R&D subcontract''Development of an In-Line, Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells'', Sinton Consulting developed prototypes for several new instruments for use in the manufacture of silicon solar cells. These instruments are based on two families of R&D instruments that were previously available, an illumination vs. open-circuit-voltage technique and the quasi-steady state RF photoconductance technique for measuring minority-carrier lifetime. Compared to the previous instruments, the new prototypes are about 20 times faster per measurement, and have automated data analysis that does not require user intervention even when confronted by challenging cases. For example, un-passivated multi-crystalline wafers with large variations in lifetime and trapping behavior can be measured sequentially without error. Five instruments have been prototyped in this project to date, including a block tester for evaluating cast or HEM silicon blocks, a CZ ingot tester, an FZ boule tester for use with long-lifetime silicon, and an in-line sample head for measuring wafers. The CZ ingot tester and the FZ boule tester are already being used within industry and there is interest in the other prototypes. For each instrument, substantial R&D work was required in developing the device physics and analysis as well as for the hardware. This work has been documented in a series of application notes and conference publications, and will result in significant improvements for both the R&D and the industrial types of instruments.

  8. Silicon-micromachined microchannel plates

    CERN Document Server

    Beetz, C P; Steinbeck, J; Lemieux, B; Winn, D R

    2000-01-01

    Microchannel plates (MCP) fabricated from standard silicon wafer substrates using a novel silicon micromachining process, together with standard silicon photolithographic process steps, are described. The resulting SiMCP microchannels have dimensions of approx 0.5 to approx 25 mu m, with aspect ratios up to 300, and have the dimensional precision and absence of interstitial defects characteristic of photolithographic processing, compatible with positional matching to silicon electronics readouts. The open channel areal fraction and detection efficiency may exceed 90% on plates up to 300 mm in diameter. The resulting silicon substrates can be converted entirely to amorphous quartz (qMCP). The strip resistance and secondary emission are developed by controlled depositions of thin films, at temperatures up to 1200 deg. C, also compatible with high-temperature brazing, and can be essentially hydrogen, water and radionuclide-free. Novel secondary emitters and cesiated photocathodes can be high-temperature deposite...

  9. Etched silicon gratings for NGST

    Energy Technology Data Exchange (ETDEWEB)

    Ge, J.; Ciarlo, D.; Kuzmenko, P.; Macintosh, B.; Alcock, C.; Cook, K.

    1999-10-28

    The authors have developed the world's first etched silicon grisms at LLNL in September 1999. The high optical surface quality of the grisms allows diffraction-limited spectral resolution in the IR wavelengths where silicon has good transmission. They estimated that the scattering light level is less than 4% at 2.2 {micro}m. Silicon can significantly increase the dispersive power of spectroscopic instruments for NGST due to its very large refractive index (n = 3.4). For example, a silicon grism with 40 mm clear entrance aperture and a 46 wedge angle can provide R = 10,000--100,000 in {approximately} 1--10 {micro}m. The same grating working in the immersed reflection mode can provide {approximately} three times higher spectral resolution than in the transmission mode. To achieve a desired spectral resolution for NGST, the spectrograph size and weight can be significantly reduced if silicon gratings are used instead of conventional gratings.

  10. Final Report

    DEFF Research Database (Denmark)

    Heiselberg, Per; Brohus, Henrik; Nielsen, Peter V.

    This final report for the Hybrid Ventilation Centre at Aalborg University describes the activities and research achievement in the project period from August 2001 to August 2006. The report summarises the work performed and the results achieved with reference to articles and reports published...

  11. Evolution of silicon sensor technology in particle physics

    CERN Document Server

    AUTHOR|(CDS)2069083

    2009-01-01

    This informative monograph describes the technological evolution of silicon detectors and their impact on high- energy particle physics. The author here marshals his own first-hand experience in the development and also the realization of the DELPHI, CDF II and the CMS tracking detector. The basic principles of small strip- and pixel-detectors are presented and also the final large-scale applications. The Evolution of Silicon Detector Technology acquaints readers with the manifold challenges involving the design of sensors and pushing this technology to the limits. The expert will find critical information that is so far only available in various slide presentation scattered over the world wide web. This practical introduction of silicon sensor technology and its day to day life in the lab also offers many examples to illustrate problems and their solutions over several detector generations.

  12. Commissioning and Performance of the LHCb Silicon Tracker

    CERN Multimedia

    van Tilburg, J; Buechler, A; Bursche , A; Chiapolini, N; Elsaesser, C; Hangartner, V; Salzmann, C; Steiner, S; Steinkamp, O; Staumann, U; Tobin, M; Vollhardt, A; Bay, A; Bettler, M O; Blanc, F; Bressieux, J; Conti, G; Fave, V; Frei, R; Gauvin, N; Gonzalez, R; Haefeli, G; Hicheur, A; Keune, A; Luisier, J; Muresan, R; Nakada, T; Needham, M; Nicolas, L; Knecht, M; Perrin, A; Potterat, C; Schneider, O; Tran, M; Aquines Gutierrez, O; Bauer, C; Britsch, M; Hofmann, W; Maciuc, F; Schmelling, M; Voss, H; Adeva, B; Esperante, D; Fungueiriño Pazos, J; Gallas, A; Pazos-Alvarez, A; Pérez-Trigo, E; Pló Casasús, M; Rogríguez Pérez, P; Saborido, J; Vázquez, P; Iakovenko, V; Okhrimenko, O; Pugatch, V

    2010-01-01

    The LHCb Silicon Tracker is a silicon micro-strip detector with a sensitive area of 12 m$^2$ and a total of 272k readout channels. The Silicon Tracker consists of two parts that use different detector modules. The detector installation was completed by early summer 2008 and the commissioning without beam has reached its finals stage, successfully overcoming most of the encountered problems. Currently, the detector has more than 99% of the channels fully functioning. Commissioning with particles has started using beam-induced events from the LHC injection tests in 2008 and 2009. These events allowed initial studies of the detector performance. Especially, the detector modules could be aligned with an accuracy of about 20 $\\mu$m. Furthermore, with the first beam collisions that took place end of 2009 we could further study the performance and improve the alignment of the detector.

  13. Quantum dynamics of charge state in silicon field evaporation

    Directory of Open Access Journals (Sweden)

    Elena P. Silaeva

    2016-08-01

    Full Text Available The charge state of an ion field-evaporating from a silicon-atom cluster is analyzed using time-dependent density functional theory coupled to molecular dynamics. The final charge state of the ion is shown to increase gradually with increasing external electrostatic field in agreement with the average charge state of silicon ions detected experimentally. When field evaporation is triggered by laser-induced electronic excitations the charge state also increases with increasing intensity of the laser pulse. At the evaporation threshold, the charge state of the evaporating ion does not depend on the electrostatic field due to the strong contribution of laser excitations to the ionization process both at low and high laser energies. A neutral silicon atom escaping the cluster due to its high initial kinetic energy is shown to be eventually ionized by external electrostatic field.

  14. Quantum dynamics of charge state in silicon field evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Silaeva, Elena P.; Uchida, Kazuki; Watanabe, Kazuyuki, E-mail: kazuyuki@rs.kagu.tus.ac.jp [Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601 (Japan)

    2016-08-15

    The charge state of an ion field-evaporating from a silicon-atom cluster is analyzed using time-dependent density functional theory coupled to molecular dynamics. The final charge state of the ion is shown to increase gradually with increasing external electrostatic field in agreement with the average charge state of silicon ions detected experimentally. When field evaporation is triggered by laser-induced electronic excitations the charge state also increases with increasing intensity of the laser pulse. At the evaporation threshold, the charge state of the evaporating ion does not depend on the electrostatic field due to the strong contribution of laser excitations to the ionization process both at low and high laser energies. A neutral silicon atom escaping the cluster due to its high initial kinetic energy is shown to be eventually ionized by external electrostatic field.

  15. Dynamic Wet Etching of Silicon through Isopropanol Alcohol Evaporation

    Directory of Open Access Journals (Sweden)

    Tiago S. Monteiro

    2015-10-01

    Full Text Available In this paper, Isopropanol (IPA availability during the anisotropic etching of silicon in Potassium Hydroxide (KOH solutions was investigated. Squares of 8 to 40 µm were patterned to (100 oriented silicon wafers through DWL (Direct Writing Laser photolithography. The wet etching process was performed inside an open HDPE (High Density Polyethylene flask with ultrasonic agitation. IPA volume and evaporation was studied in a dynamic etching process, and subsequent influence on the silicon etching was inspected. For the tested conditions, evaporation rates for water vapor and IPA were determined as approximately 0.0417 mL/min and 0.175 mL/min, respectively. Results demonstrate that IPA availability, and not concentration, plays an important role in the definition of the final structure. Transversal SEM (Scanning Electron Microscopy analysis demonstrates a correlation between microloading effects (as a consequence of structure spacing and the angle formed towards the (100 plane.

  16. Modelling and fabrication of high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Smith, A.W.; Salami, J. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical Engineering

    1991-10-01

    This report covers the research conducted on modelling and development of high-efficiency silicon solar cells during the period May 1989 to August 1990. First, considerable effort was devoted toward developing a ray-tracing program for the photovoltaic community to quantify and optimize surface texturing for solar cells. Second, attempts were made to develop a hydrodynamic model for device simulation. Such a model is somewhat slower than drift-diffusion type models like PC-1D, but it can account for more physical phenomena in the device, such as hot carrier effects, temperature gradients, thermal diffusion, and lattice heat flow. In addition, Fermi-Dirac statistics have been incorporated into the model to deal with heavy doping effects more accurately. Third and final component of the research includes development of silicon cell fabrication capabilities and fabrication of high-efficiency silicon cells. 84 refs., 46 figs., 10 tabs.

  17. Micromachined silicon seismic transducers

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Sniegowski, J.J.; Armour, D.L.; Fleming, R.P.

    1995-08-01

    Batch-fabricated silicon seismic transducers could revolutionize the discipline of CTBT monitoring by providing inexpensive, easily depolyable sensor arrays. Although our goal is to fabricate seismic sensors that provide the same performance level as the current state-of-the-art ``macro`` systems, if necessary one could deploy a larger number of these small sensors at closer proximity to the location being monitored in order to compensate for lower performance. We have chosen a modified pendulum design and are manufacturing prototypes in two different silicon micromachining fabrication technologies. The first set of prototypes, fabricated in our advanced surface- micromachining technology, are currently being packaged for testing in servo circuits -- we anticipate that these devices, which have masses in the 1--10 {mu}g range, will resolve sub-mG signals. Concurrently, we are developing a novel ``mold`` micromachining technology that promises to make proof masses in the 1--10 mg range possible -- our calculations indicate that devices made in this new technology will resolve down to at least sub-{mu}G signals, and may even approach to 10{sup {minus}10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

  18. Microplasticity of silicon crystals

    Science.gov (United States)

    Drozhzhin, A. I.; Sidel'Nikov, I. V.; Antipov, S. A.; Sedykh, N. K.

    1980-05-01

    The low-frequency (˜1 Hz) internal friction (Q-1) method was used to study the microplasticity of silicon whisker crystals grown by the method of chemical gas-transport reactions in a closed ampoule. A study was made of p-type crystals with the growth axis , 1 60 μ in diameter, working length 1 3 mm, both in the original state and after plastic (γ ˜ 1%) deformtion by torsion. The temperature and amplitude dependences of Q-1 were studied in ˜5·10-5 torr vacuum. The amplitude of alternating vibrations was within the range ˜10-5 10-3 and the axial stresses were ˜106 107 N/m2. The experimental results led to the conclusion that the microplasticity of undeformed silicon whiskers was due to heterogeneous nucleation of dislocations in stress concentration regions near surface defects, assisted by thermal fluctuations. In deformed whiskers the microplasticity was attributed to the nucleation and motion along dislocations of single and double thermal kinks in accordance with the Seeger model.

  19. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Meng Tao

    2010-12-22

    The objective of this DOE SAI project is to demonstrate the feasibility of electrodeposited and solution-doped transparent conducting oxides (TCOs) such as zinc oxide with resistivity in the mid-10{sup -4} {Omega}-cm range. The target application is an 'on-top' TCO which can be deposited on semiconductors in thin-film and future solar cells including amorphous silicon, copper indium gallium selenide and emerging solar cells. There is no solution-prepared on-top TCO currently used in commercial solar cells. This project, if successful, will fill this gap. Our technical objectives include electrodeposited TCOs with (1) resistivity in the mid-10{sup -4} {Omega}-cm range, (2) post-deposition annealing below 300 C and (3) no-vacuum processing or low-vacuum processing. All the three research objectives listed above have been accomplished in the 14-month period from July 1, 2009 through September 30, 2010. The most noticeable accomplishments of this project are (1) identification of a terawatt-scale dopant for zinc oxide, i.e. yttrium, whose known reserve is enough for 60 peak terawatts of thin-film solar cells; (2) demonstration of a record-low resistivity, 6.3 x 10{sup -5} {Omega}-cm, in solution-deposited zinc oxide with an abundant dopant; and (3) the record-low resistivity was accomplished with a maximum process temperature of 300 C and without vacuum annealing. Industrial applications of the new yttrium-doped zinc oxide are being pursued, including (1) green deposition of yttrium-doped zinc oxide to reduce water consumption during deposition and (2) search for an industrial partner to develop an electrochemical tool for large-area uniform deposition of yttrium-doped zinc oxide.

  20. Selective emitter using porous silicon for crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Inyong; Kim, Kyunghae; Kim, Youngkuk; Han, Kyumin; Kyeong, Doheon; Kwon, Taeyoung; Vinh Ai, Dao; Lee, Jeongchul; Yi, Junsin [School of Information and Communication Engineering, Sungkyunkwan University, Chunchun-dong, Jangan-Gu, Suwon-City, Kyunggi-Do 440-746 (Korea); Thamilselvan, M. [School of Information and Communication Engineering, Sungkyunkwan University, Chunchun-dong, Jangan-Gu, Suwon-City, Kyunggi-Do 440-746 (Korea); Government College of Technology, Coimbatore, Tamilnadu (India); Ju, Minkyu; Lee, Kyungsoo [KPE Ins. Chunchun-dong, Jangan-Gu, Suwon-City, Kyunggi-Do 440-746 (Korea)

    2009-06-15

    This study is devoted to the formation of high-low-level-doped selective emitter for crystalline silicon solar cells for photovoltaic application. We report here the formation of porous silicon under chemical reaction condition. The chemical mixture containing hydrofluoric and nitric acid, with de-ionized water, was used to make porous on the half of the silicon surface of size 125 x 125 cm. Porous and non-porous areas each share half of the whole silicon surface. H{sub 3}PO{sub 4}:methanol gives the best deposited layer with acceptable adherence and uniformity on the non-porous and porous areas of the silicon surface to get high- and low-level-doped regions. The volume concentration of H{sub 3}PO{sub 4} does not exceed 10% of the total volume emulsion. Phosphoric acid was used as an n-type doping source to make emitter for silicon solar cells. The measured emitter sheet resistances at the high- and low-level-doped regions were 30-35 and 97-474 {omega}/{open_square} respectively. A simple process for low- and high-level doping has been achieved by forming porous and porous-free silicon surface, in this study, which could be applied for solar cells selective emitter doping. (author)

  1. Stoichiometry of silicon-rich dielectrics for silicon nanocluster formation

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Jorge; Morales, Alfredo; Dominguez, Carlos [Centro Nacional de Microelectronica, IMB-CNM (CSIC), Campus UAB, 08193 Cerdanyola del Valles (Spain); Peralvarez, Mariano; Garrido, Blas [EME, Departament d' Electronica, Universitat de Barcelona, 08028 Barcelona (Spain)

    2011-03-15

    Silicon photonics has been bred by several techniques including Chemical Vapour Deposition (CVD) and ion implantation amongst others in order to synthesize silicon nanoclusters with CMOS-compatible technologies. Most of these techniques end up relying on the formation of nanoclusters through the diffusion and segregation of silicon atoms in a silicon-rich dielectric matrix. In this work we present a parallel analysis on silicon rich dielectric layers obtained by different methods. X-Ray Photoelectron Spectroscopy, ellipsometry and photoluminescence are used to characterize Low Pressure CVD and Plasma Enhanced CVD samples in the same theoretical silicon excess range. The analysis shows that independently on the obtaining method the initial concentration of silicon excess can be used to estimate some properties. The actual binding of the atoms can change as well regardless of their initial quantity. However secondary parameters such as the obtaining temperature and the nitrogen concentration in the layer have to be taken into account. Therefore, experimental parameters such as the flow ratio between reactant gases or the refractive index prove to be insufficient if samples obtained by different methods are compared. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Soft chemical synthesis of silicon nanosheets and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Hideyuki; Ikuno, Takashi [Toyota Central R& D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan)

    2016-12-15

    Two-dimensional silicon nanomaterials are expected to show different properties from those of bulk silicon materials by virtue of surface functionalization and quantum size effects. Since facile fabrication processes of large area silicon nanosheets (SiNSs) are required for practical applications, a development of soft chemical synthesis route without using conventional vacuum processes is a challenging issue. We have recently succeeded to prepare SiNSs with sub-nanometer thicknesses by exfoliating layered silicon compounds, and they are found to be composed of crystalline single-atom-thick silicon layers. In this review, we present the synthesis and modification methods of SiNSs. These SiNSs have atomically flat and smooth surfaces due to dense coverage of organic moieties, and they are easily self-assembled in a concentrated state to form a regularly stacked structure. We have also characterized the electron transport properties and the electronic structures of SiNSs. Finally, the potential applications of these SiNSs and organic modified SiNSs are also reviewed.

  3. Aluminum-doped crystalline silicon and its photovoltaic application

    Science.gov (United States)

    Yuan, Shuai; Yu, Xuegong; Gu, Xin; Feng, Yan; Lu, Jinggang; Yang, Deren

    2016-11-01

    The impact of Al doping with the concentrations in the range of 0.01-0.1 ppmw on the performance of silicon wafers and solar cells is studied. The effective segregation coefficient of impurity keff of Al in Si is obtained as 0.0029, which is calculated as 0.0027, supporting that Al should be totally ionized and occupy the substitutional sites in silicon and serve as the +1 dopant. It is found that the open-circuit voltages (Uoc), short-circuit currents (Isc) and photo-electrical conversion efficiency of the Al-containing solar cells decrease with the increase of Al concentrations because of Al-related deep level recombination centers. The average absolute efficiency of Al-doped silicon solar cells is 0.34% lower than that of Ga-doped-only cells, and the largest difference can be about 0.62%. Moreover, Al doped silicon solar cells show no light induced efficiency degradation, and the average efficiency maintains above 17.78%, which is comparable at the final state to that of normal B-doped silicon solar cells.

  4. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Stinis, Panos [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-07

    This is the final report for the work conducted at the University of Minnesota (during the period 12/01/12-09/18/14) by PI Panos Stinis as part of the "Collaboratory on Mathematics for Mesoscopic Modeling of Materials" (CM4). CM4 is a multi-institution DOE-funded project whose aim is to conduct basic and applied research in the emerging field of mesoscopic modeling of materials.

  5. Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites

    Science.gov (United States)

    Corman, Gregory Scot; Luthra, Krishan Lal

    1999-01-01

    A fiber-reinforced silicon--silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon--silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

  6. Lipid membranes on nanostructured silicon.

    Energy Technology Data Exchange (ETDEWEB)

    Slade, Andrea Lynn; Lopez, Gabriel P. (University of New Mexico, Albuquerque, NM); Ista, Linnea K. (University of New Mexico, Albuquerque, NM); O' Brien, Michael J. (University of New Mexico, Albuquerque, NM); Sasaki, Darryl Yoshio; Bisong, Paul (University of New Mexico, Albuquerque, NM); Zeineldin, Reema R. (University of New Mexico, Albuquerque, NM); Last, Julie A.; Brueck, Stephen R. J. (University of New Mexico, Albuquerque, NM)

    2004-12-01

    A unique composite nanoscale architecture that combines the self-organization and molecular dynamics of lipid membranes with a corrugated nanotextured silicon wafer was prepared and characterized with fluorescence microscopy and scanning probe microscopy. The goal of this project was to understand how such structures can be assembled for supported membrane research and how the interfacial interactions between the solid substrate and the soft, self-assembled material create unique physical and mechanical behavior through the confinement of phases in the membrane. The nanometer scale structure of the silicon wafer was produced through interference lithography followed by anisotropic wet etching. For the present study, a line pattern with 100 nm line widths, 200 nm depth and a pitch of 360 nm pitch was fabricated. Lipid membranes were successfully adsorbed on the structured silicon surface via membrane fusion techniques. The surface topology of the bilayer-Si structure was imaged using in situ tapping mode atomic force microscopy (AFM). The membrane was observed to drape over the silicon structure producing an undulated topology with amplitude of 40 nm that matched the 360 nm pitch of the silicon structure. Fluorescence recovery after photobleaching (FRAP) experiments found that on the microscale those same structures exhibit anisotropic lipid mobility that was coincident with the silicon substructure. The results showed that while the lipid membrane maintains much of its self-assembled structure in the composite architecture, the silicon substructure indeed influences the dynamics of the molecular motion within the membrane.

  7. Intracellular trafficking of silicon particles and logic-embedded vectors

    Science.gov (United States)

    Ferrati, Silvia; Mack, Aaron; Chiappini, Ciro; Liu, Xuewu; Bean, Andrew J.; Ferrari, Mauro; Serda, Rita E.

    2010-08-01

    Mesoporous silicon particles show great promise for use in drug delivery and imaging applications as carriers for second-stage nanoparticles and higher order particles or therapeutics. Modulation of particle geometry, surface chemistry, and porosity allows silicon particles to be optimized for specific applications such as vascular targeting and avoidance of biological barriers commonly found between the site of drug injection and the final destination. In this study, the intracellular trafficking of unloaded carrier silicon particles and carrier particles loaded with secondary iron oxide nanoparticles was investigated. Following cellular uptake, membrane-encapsulated silicon particles migrated to the perinuclear region of the cell by a microtubule-driven mechanism. Surface charge, shape (spherical and hemispherical) and size (1.6 and 3.2 μm) of the particle did not alter the rate of migration. Maturation of the phagosome was associated with an increase in acidity and acquisition of markers of late endosomes and lysosomes. Cellular uptake of iron oxide nanoparticle-loaded silicon particles resulted in sorting of the particles and trafficking to unique destinations. The silicon carriers remained localized in phagosomes, while the second stage iron oxide nanoparticles were sorted into multi-vesicular bodies that dissociated from the phagosome into novel membrane-bound compartments. Release of iron from the cells may represent exocytosis of iron oxide nanoparticle-loaded vesicles. These results reinforce the concept of multi-functional nanocarriers, in which different particles are able to perform specific tasks, in order to deliver single- or multi-component payloads to specific sub-cellular compartments.Mesoporous silicon particles show great promise for use in drug delivery and imaging applications as carriers for second-stage nanoparticles and higher order particles or therapeutics. Modulation of particle geometry, surface chemistry, and porosity allows silicon

  8. Silicon force sensor

    Energy Technology Data Exchange (ETDEWEB)

    Galambos, Paul C.; Crenshaw, Thomas B.; Nishida, Erik E.; Burnett, Damon J.; Lantz, Jeffrey W.

    2016-07-05

    The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload upon the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor.

  9. Silicon-to-silicon wafer bonding using evaporated glass

    DEFF Research Database (Denmark)

    Weichel, Steen; Reus, Roger De; Lindahl, M.

    1998-01-01

    Anodic bending of silicon to silicon 4-in. wafers using an electron-beam evaporated glass (Schott 8329) was performed successfully in air at temperatures ranging from 200 degrees C to 450 degrees C. The composition of the deposited glass is enriched in sodium as compared to the target material...... of silicon/glass structures in air around 340 degrees C for 15 min leads to stress-free structures. Bonded wafer pairs, however, show no reduction in stress and always exhibit compressive stress. The bond yield is larger than 95% for bonding temperatures around 350 degrees C and is above 80% for bonding...... from 25 N/mm(2) to 0 N/mm(2) at 200 degrees C. A weak dependence on feature size was observed. For bonding temperatures higher than 300 degrees C fracture occurs randomly in the bulk of the silicon, whereas for bonding temperatures lower than 300 degrees C fracture always occurs at the bonding...

  10. Silicon Carbide Nanotube Synthesized

    Science.gov (United States)

    Lienhard, Michael A.; Larkin, David J.

    2003-01-01

    Carbon nanotubes (CNTs) have generated a great deal of scientific and commercial interest because of the countless envisioned applications that stem from their extraordinary materials properties. Included among these properties are high mechanical strength (tensile and modulus), high thermal conductivity, and electrical properties that make different forms of single-walled CNTs either conducting or semiconducting, and therefore, suitable for making ultraminiature, high-performance CNT-based electronics, sensors, and actuators. Among the limitations for CNTs is their inability to survive in high-temperature, harsh-environment applications. Silicon carbon nanotubes (SiCNTs) are being developed for their superior material properties under such conditions. For example, SiC is stable in regards to oxidation in air to temperatures exceeding 1000 C, whereas carbon-based materials are limited to 600 C. The high-temperature stability of SiCNTs is envisioned to enable high-temperature, harsh-environment nanofiber- and nanotube-reinforced ceramics. In addition, single-crystal SiC-based semiconductors are being developed for hightemperature, high-power electronics, and by analogy to CNTs with silicon semiconductors, SiCNTs with single-crystal SiC-based semiconductors may allow high-temperature harsh-environment nanoelectronics, nanosensors, and nanoactuators to be realized. Another challenge in CNT development is the difficulty of chemically modifying the tube walls, which are composed of chemically stable graphene sheets. The chemical substitution of the CNTs walls will be necessary for nanotube self-assembly and biological- and chemical-sensing applications. SiCNTs are expected to have a different multiple-bilayer wall structure, allowing the surface Si atoms to be functionalized readily with molecules that will allow SiCNTs to undergo self-assembly and be compatible with a variety of materials (for biotechnology applications and high-performance fiber-reinforced ceramics).

  11. Poly(3-hexylthiophene) films by electrospray deposition for crystalline silicon/organic hybrid junction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hiate, Taiga; Miyauchi, Naoto; Tang, Zeguo; Ishikawa, Ryo; Ueno, Keiji; Shirai, Hajime [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura, Saitama 858-3676 (Japan)

    2012-10-15

    The electrospray deposition (ESD) of poly(3-hexylthiophene) (P3HT) and conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) on P3HT for use in crystalline silicon/organic hybrid heterojunction solar cells on CZ crystalline silicon (c-Si) (100) wafer was investigated using real-time characterization by spectroscopic ellipsometry (SE). In contrast to the nonuniform deposition of products frequently obtained by conventional spin-coating, a uniform deposition of P3HT and PEDOT:PSS films were achieved on flat and textured hydrophobic c-Si(100) wafers by adjusting the deposition conditions. The c-Si/P3HT/PEDOT:PSS heterojunction solar cells exhibited efficiencies of 4.1 and 6.3% on flat and textured c-Si(100) wafers, respectively. These findings suggest that ESD is a promising method for the uniform deposition of P3HT and PEDOT:PSS films on flat and textured hydrophobic substrates. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. 75 FR 28560 - Prestressed Concrete Steel Wire Strand From the People's Republic of China: Final Determination...

    Science.gov (United States)

    2010-05-21

    ... not to value movement expenses between the pickling plant and the main factory as a factor of...''), as amplified by Notice of Final Determination of Sales at Less Than Fair Value: Silicon Carbide From the People's Republic of China, 59 FR 22585 (May 2, 1994) (``Silicon Carbide''), and 19 CFR 351.107(d...

  13. Efficiency Enhancement of Silicon Solar Cells by Porous Silicon Technology

    Directory of Open Access Journals (Sweden)

    Eugenijus SHATKOVSKIS

    2012-09-01

    Full Text Available Silicon solar cells produced by a usual technology in p-type, crystalline silicon wafer were investigated. The manufactured solar cells were of total thickness 450 mm, the junction depth was of 0.5 mm – 0.7 mm. Porous silicon technologies were adapted to enhance cell efficiency. The production of porous silicon layer was carried out in HF: ethanol = 1 : 2 volume ratio electrolytes, illuminating by 50 W halogen lamps at the time of processing. The etching current was computer-controlled in the limits of (6 ÷ 14 mA/cm2, etching time was set in the interval of (10 ÷ 20 s. The characteristics and performance of the solar cells samples was carried out illuminating by Xenon 5000 K lamp light. Current-voltage characteristic studies have shown that porous silicon structures produced affect the extent of dark and lighting parameters of the samples. Exactly it affects current-voltage characteristic and serial resistance of the cells. It has shown, the formation of porous silicon structure causes an increase in the electric power created of solar cell. Conversion efficiency increases also respectively to the initial efficiency of cell. Increase of solar cell maximum power in 15 or even more percent is found. The highest increase in power have been observed in the spectral range of Dl @ (450 ÷ 850 nm, where ~ 60 % of the A1.5 spectra solar energy is located. It has been demonstrated that porous silicon technology is effective tool to improve the silicon solar cells performance.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2428

  14. Silicon Quantum Dots for Quantum Information Processing

    Science.gov (United States)

    2013-11-01

    16 2.2.2 Si/SiGe Heterostructures . . . . . . . . . . . . . . . . . . . 18 2.2.3 Silicon Nanowires ...Recently, silicon MOS, silicon/silicon- germanium (Si/SiGe) heterostructures and silicon nanowire architectures have also achieved spin manipulation and...Churchill, D. J. Reilly, J. Xiang, C. M. Lieber, and C. M. Marcus. A Ge/Si heterostructure nanowire -based double quantum dot with integrated charge

  15. Solar silicon refining; Inclusions, settling, filtration, wetting

    OpenAIRE

    Ciftja, Arjan

    2009-01-01

    The main objective of the present work is the removal of inclusions from silicon scrap and metallurgical grade silicon. To reach this goal, two various routes are investigated. First, settling of SiC particles from molten silicon followed by directional solidification is reported in this thesis. Then, removal of SiC and Si3N4 inclusions in silicon scrap by filtration with foam filters and wettabilities of silicon on graphite materials are studied. To supply the increasing needs of the...

  16. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    R Paul Drake

    2004-01-12

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves.

  17. Components/factors of the Czech version of the Physical Self Perception Profile (PSPP-CZ among high school students [Komponenty/faktory české verze dotazníku tělesného sebepojetí (PSPP-CZ u středoškolských studentů

    Directory of Open Access Journals (Sweden)

    Vlastimil Kudláček

    2010-12-01

    Full Text Available BACKGROUND: The physical self has been widely investigated as a determinant of exercise behaviors as well as a contributor to mental health and well being (Fox, 1997. Self esteem has been generally accepted as an important mediator of exercise and self esteem (Fox, 2000; Sonstroem, 1997. Understanding self development processes has increased in importance as self esteem and self perception components have become increasingly valued in educational, clinical and community health programs (Ferreira & Fox, 2008. In order to examine the relationships between various levels of physical activities and self perception we need to use standardized instruments to measure physical self perception among Czech teenagers. OBJECTIVE: The purpose of this study was to analyse the structure of the translated PSPP-CZ questionnaire among the population of high school students by finding components of PSPP-CZ using principal component analysis. The Physical Self Perception Profile (PSPP has never been used in the CZ population before. METHODS: Participants were high school students from five schools representing three kinds of high schools in the Czech Republic. Of these participants, 666 were boys and 403 were girls. The average age of the participants was 17.00 (± 1.34 in boys and 16.63 (± 1.39 in girls. Participants received a test battery containing a Czech version of PSPP (Fox, 1990. PSPP has four subscales: (a sports competence – SPORT; (b attractiveness of the figure – BODY; (c physical strength and musculature – STRENGTH; and (d physical conditioning and exercise – CONDITION (Fox, 1990. RESULTS: Data were analyzed using SPSS PC 11.0. Cronbach Alpha, representing the internal consistency measure consisted of: (a sport subscale (males = .86, females = .86; (b physical condition subscales (males = .82, females = .85; (c attractiveness of figure subscales (males = .78, females = .88; and (d strength subscale (males = .87, females = .85. Initially we

  18. Mesoporous silicon synthesis and applications in Li-ion batteries and solar hydrogen fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Donghai; Dai, Fang; Yi, Ran; Zai, Jianto

    2017-05-23

    We provide a mesoporous silicon material (PSi) prepared via a template-free and HF-free process. The production process is facile and scalable, and it may be conducted under mild reaction conditions. The silicon may be produced directly by the reduction of a silicon-halogenide precursor (for example, SiCl.sub.4) with an alkaline alloy (for example, NaK alloy). The resulting Si-salt matrix is then annealed for the pore formation and crystallite growth. Final product is obtained by removal of the salt by-products with water.

  19. Induction of resistance by silicon in wheat plants to alate and apterous morphs of Sitobion avenae (Hemiptera: Aphididae).

    Science.gov (United States)

    Dias, P A S; Sampaio, M V; Rodrigues, M P; Korndörfer, A P; Oliveira, R S; Ferreira, S E; Korndörfer, G H

    2014-08-01

    Despite the knowledge about the effects of silicon augmenting antibiosis and nonpreference of plants by apterous aphids, few studies exist on such effects with alate aphids. This study evaluated the effects of silicon fertilization on the biology of alate and apterous morphs of Sitobion avenae (F.) (Hemiptera: Aphididae), and the effect on nonpreference by S. avenae alates for wheat plants with or without silicon fertilization. A method for rearing aphids on detached leaves was evaluated comparing the biology of apterous aphids reared on wheat leaf sections and on whole plants with and without silicon fertilization. Because the use of detached leaves was a reliable method, the effect of silicon fertilization on the biology of apterous and alate S. avenae was assessed using wheat leaf sections. Biological data of aphids were used to calculate a fertility life table. Finally, the effect of silicon fertilization on the nonpreference of alate aphids was carried out for both vegetative and reproductive phases of wheat. Thirty alate aphids were released in the center of a cage, and the number of aphids per whole plant with or without silicon fertilization was observed. Silicon fertilization induced antibiosis resistance in wheat plants to apterous morphs as shown by reduced fecundity, reproductive period, longevity, intrinsic rate of increase, and net reproductive rate; however, alates were unaffected. Plants that received silicon fertilization had fewer alate aphids in both the vegetative and reproductive phases. Thus, silicon fertilization can reduce colonization by alates, enhancing nonpreference resistance, and population growth of apterous S. avenae in wheat plants.

  20. Argon plasma treatment of silicon nitride (SiN) for improved antireflection coating on c-Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Hemanta; Mitra, Suchismita; Saha, Hiranmay; Datta, Swapan Kumar; Banerjee, Chandan, E-mail: chandanbanerjee74@gmail.com

    2017-01-15

    Highlights: • Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell. • The reduction in reflection due to the formation of a silicon oxynitride/silicon nitride double layer. • EQE reveals a relative increase of 2.72% in J{sub sc} and 4.46% in conversion efficiency. - Abstract: Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell is presented here. Hydrogenated silicon nitride (a-SiN:H) layer has been deposited on a silicon substrate by Plasma Enhanced Chemical Vapour Deposition (PECVD) using a mixture of silane (SiH{sub 4}), ammonia (NH{sub 3}) and hydrogen (H{sub 2}) gases followed by a argon plasma treatment. Optical analysis reveals a significant reduction in reflectance after argon plasma treatment of silicon nitride layer. While FESEM shows nanostructures on the surface of the silicon nitride film, FTIR reveals a change in Si−N, Si−O and N−H bonds. On the other hand, ellipsometry shows the variation of refractive index and formation of double layer. Finally, a c-Si solar cell has been fabricated with the said anti-reflection coating. External quantum efficiency reveals a relative increase of 2.72% in the short circuit current density and 4.46% in conversion efficiency over a baseline efficiency of 16.58%.

  1. Stiction, friction, and wear reduction in silicon microelectromechanical systems

    Science.gov (United States)

    Mantiziba, Fadziso Mabel

    Current reliability issues in silicon based microelectromechanical systems (MEMS) pose a challenge in the advancement of this pervasive technology. Silicon Microsystems are encumbered with adhesion induced catastrophic failures (stiction) during the final fabrication step where a wet chemical etch release is often conducted to produce functional, suspended microstructures. Irreversible adhesion of active device layer components to the substrate can drastically reduce yields of fully functional devices. Potential in-use problems of a tribological nature also limit the reliability and device lifetimes of these microstructures, particularly where intermittent or continuous contacting of surfaces occurs during a device's normal operation. Understanding the fundamental tribological properties such as friction coefficients and wear mechanisms that occur in the normal operation of these devices is a necessity in providing potential long term solutions to such reliability issues. A unique, simple, yet inexpensive solution to release related adhesion failures that utilizes a temporary physical barrier during the final rinsing stage of a typical silicon wet etch release process is presented. This temporary barrier is accomplished using polystyrene microspheres that prevent contact between the substrate and the components of the suspended device layer during drying. The microspheres are subsequently removed using a plasma etching process. Improvement of yields of stiction-free, functional devices >90% in comparison to rinse liquids have been demonstated using this process. To address tribological reliability issues for silicon MEMS, friction testing devices are utilized to measure the friction coefficients of silicon. Thin ceramic coatings of oxides of aluminum, zirconium, or titanium are applied to the silicon MEMS devices using the atomic layer deposition technique and tested for comparison to non-coated silicon surfaces. Testing conducted under controlled humidity shows

  2. Characterization of silicon-silicon carbide ceramic derived from carbon-carbon silicon carbide composites

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Vijay K. [Indian Institute of Technology, Varanasi (India). Dept. of Mechanical Engineering; Krenkel, Walter [Univ. of Bayreuth (Germany). Dept. of Ceramic Materials Engineering

    2013-04-15

    The main objective of the present work is to process porous silicon - silicon carbide (Si - SiC) ceramic by the oxidation of carboncarbon silicon carbide (C/C - SiC) composites. Phase studies are performed on the oxidized porous composite to examine the changes due to the high temperature oxidation. Further, various characterization techniques are performed on Si- SiC ceramics in order to study the material's microstructure. The effects of various parameters such as fiber alignment (twill weave and short/chopped fiber) and phenolic resin type (resol and novolak) are characterized.

  3. Imprinted silicon-based nanophotonics

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Olsen, Brian Bilenberg; Frandsen, Lars Hagedorn

    2007-01-01

    We demonstrate and optically characterize silicon-on-insulator based nanophotonic devices fabricated by nanoimprint lithography. In our demonstration, we have realized ordinary and topology-optimized photonic crystal waveguide structures. The topology-optimized structures require lateral pattern ...

  4. Optical information capacity of silicon

    CERN Document Server

    Dimitropoulos, Dimitris

    2014-01-01

    Modern computing and data storage systems increasingly rely on parallel architectures where processing and storage load is distributed within a cluster of nodes. The necessity for high-bandwidth data links has made optical communication a critical constituent of modern information systems and silicon the leading platform for creating the necessary optical components. While silicon is arguably the most extensively studied material in history, one of its most important attributes, an analysis of its capacity to carry optical information, has not been reported. The calculation of the information capacity of silicon is complicated by nonlinear losses, phenomena that emerge in optical nanowires as a result of the concentration of optical power in a small geometry. Nonlinear losses are absent in silica glass optical fiber and other common communication channels. While nonlinear loss in silicon is well known, noise and fluctuations that arise from it have never been considered. Here we report sources of fluctuations...

  5. Characterization of Czochralski Silicon Detectors

    CERN Document Server

    Luukka, Panja-Riina

    2012-01-01

    This thesis describes the characterization of irradiated and non-irradiated segmenteddetectors made of high-resistivity (>1 kΩcm) magnetic Czochralski (MCZ) silicon. It isshown that the radiation hardness (RH) of the protons of these detectors is higher thanthat of devices made of traditional materials such as Float Zone (FZ) silicon or DiffusionOxygenated Float Zone (DOFZ) silicon due to the presence of intrinsic oxygen (> 5 x1017 cm-3). The MCZ devices therefore present an interesting alternative for future highenergy physics experiments. In the large hadron collider (LHC), the RH of the detectorsis a critical issue due to the high luminosity (1034 cm-2s-1) corresponding to the expectedtotal fluencies of fast hadrons above 1015 cm-2. This RH improvement is important sinceradiation damage in the detector bulk material reduces the detector performance andbecause some of the devices produced from standard detector-grade silicon, e.g. FZsilicon with negligible oxygen concentration, might not survive the plann...

  6. SILICONE RUBBER MOULDS FOR FOOTWEAR

    Directory of Open Access Journals (Sweden)

    Cornelia LUCA

    2013-05-01

    Full Text Available The leather confections industry uses the silicone rubber moulds for the symbols,notices and models stamping on the footwear or morocco goods parts. The paper presents somecontributions in this kind of devices manufacturing technology

  7. Silicon Solar Cell Turns 50

    Energy Technology Data Exchange (ETDEWEB)

    Perlin, J.

    2004-08-01

    This short brochure describes a milestone in solar (or photovoltaic, PV) research-namely, the 50th anniversary of the invention of the first viable silicon solar cell by three researchers at Bell Laboratories.

  8. Ultra-fast silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sadrozinski, H. F.-W., E-mail: hartmut@scipp.ucsc.edu [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Ely, S.; Fadeyev, V.; Galloway, Z.; Ngo, J.; Parker, C.; Petersen, B.; Seiden, A.; Zatserklyaniy, A. [Santa Cruz Institute for Particle Physics, UC Santa Cruz, Santa Cruz, CA 95064 (United States); Cartiglia, N.; Marchetto, F. [INFN Torino, Torino (Italy); Bruzzi, M.; Mori, R.; Scaringella, M.; Vinattieri, A. [University of Florence, Department of Physics and Astronomy, Sesto Fiorentino, Firenze (Italy)

    2013-12-01

    We propose to develop a fast, thin silicon sensor with gain capable to concurrently measure with high precision the space (∼10 μm) and time (∼10 ps) coordinates of a particle. This will open up new application of silicon detector systems in many fields. Our analysis of detector properties indicates that it is possible to improve the timing characteristics of silicon-based tracking sensors, which already have sufficient position resolution, to achieve four-dimensional high-precision measurements. The basic sensor characteristics and the expected performance are listed, the wide field of applications are mentioned and the required R and D topics are discussed. -- Highlights: •We are proposing thin pixel silicon sensors with 10's of picoseconds time resolution. •Fast charge collection is coupled with internal charge multiplication. •The truly 4-D sensors will revolutionize imaging and particle counting in many applications.

  9. Scattering characteristics from porous silicon

    Directory of Open Access Journals (Sweden)

    R. Sabet-Dariani

    2000-12-01

    Full Text Available   Porous silicon (PS layers come into existance as a result of electrochemical anodization on silicon. Although a great deal of research has been done on the formation and optical properties of this material, the exact mechanism involved is not well-understood yet.   In this article, first, the optical properties of silicon and porous silicon are described. Then, previous research and the proposed models about reflection from PS and the origin of its photoluminescence are reveiwed. The reflecting and scattering, absorption and transmission of light from this material, are then investigated. These experiments include,different methods of PS sample preparation their photoluminescence, reflecting and scattering of light determining different characteristics with respect to Si bulk.

  10. Synthesis, passivation and charging of silicon nanocrystals

    Science.gov (United States)

    Boer, Elizabeth A.

    2001-10-01

    Silicon nanocrystals are intriguing from both a fundamental and an applied physics point of view. The efficient room temperature luminescence exhibited by Si nanocrystals (as compared to bulk silicon) and the apparent size-dependent bandgap, of Si nanocrystals are two incompletely explained phenomena. Meanwhile, the applied physicist may take advantage of the optical and electronic properties of small Si structures to build devices not possible with only bulk silicon. In this thesis, nanocrystal samples produced by aerosol techniques were investigated. The aerosol samples were size-classified in the size range of 2-50 nm with a size variation of 15-20%. Conducting tip atomic force microscopy (AFM) was used to manipulate and investigate the samples' charging characteristics. The AFM was used to inject charge into single Si nanocrystals and to observe the dissipation. The charging characteristics of samples made by ion implantation and annealing were also explored. An atomic force microscope was used to locally inject, detect and quantify the amount and location of charge in SiO 2 films containing Si nanocrystals (size ~2-6 nm). By comparison with control samples, charge trapping was shown to be due to nanocrystals and not ion implantation-induced defects in these samples. Two models were developed for quantitative charge imaging with an atomic force microscope, one appropriate for non- contact mode and the other for intermittent contact (tapping) mode imaging. From the models, estimates of the best charge sensitivity of an unbiased standard AFM cantilever were found to be on the order of a few electrons. The models were used to estimate the amount of charge injected in the charging experiments: in typical experiments, on the order of 60 electrons were injected in an isolated Si nanoparticle, and a few hundred electrons were injected in SiO2 films containing Si nanocrystals. Finally, for optical studies, nanocrystal passivation with hydrogen and SiO2 were briefly

  11. New applications of silicon micromachining

    Energy Technology Data Exchange (ETDEWEB)

    Lauf, R.J.; Wood, R.F.; Fleming, P.H.; Bauer, M.L.

    1988-06-01

    The use of photolithography and anisotropic etching of silicon wafers to make strong, thin membranes has created a large family of miniature sensing devices such as pressure transducers and accelerometers. This report describes several entirely new devices in which silicon membranes are used for their strength and for their transparency to certain kinds of radiation. Two applications are described: a rugged alpha detector and a fluid sample cell for small-angle x-ray scattering. 8 refs., 12 figs., 2 tabs.

  12. Topological Order in Silicon Photonics

    Science.gov (United States)

    2017-02-07

    AFRL-AFOSR-VA-TR-2017-0037 Topological orders in Silicon photonics Mohammad Hafezi MARYLAND UNIV COLLEGE PARK 3112 LEE BLDG COLLEGE PARK, MD 20742...15 SEP 2016 4. TITLE AND SUBTITLE Topological Order in Silicon Photonics 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA-9550-14-1-0267 5c. PROGRAM...DISTRIBUTION/AVAILABILITY STATEMENT DISTRIBUTION A: Distribution approved for public release. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Topological features

  13. Silicon Sensors for HEP Experiments

    CERN Document Server

    Dierlamm, Alexander Hermann

    2017-01-01

    With increasing luminosity of accelerators for experiments in High Energy Physics the demands on the detectors increase as well. Especially tracking and vertexing detectors made of silicon sensors close to the interaction point need to be equipped with more radiation hard devices. This article introduces the different types of silicon sensors, describes measures to increase radiation hardness and provides an overview of present upgrade choices of HEP experiments.

  14. Silicone nanocomposite coatings for fabrics

    Science.gov (United States)

    Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

    2011-01-01

    A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

  15. Metallization of Large Silicon Wafers

    Science.gov (United States)

    Pryor, R. A.

    1978-01-01

    A metallization scheme was developed which allows selective plating of silicon solar cell surfaces. The system is comprised of three layers. Palladium, through the formation of palladium silicide at 300 C in nitrogen, makes ohmic contact to the silicon surface. Nickel, plated on top of the palladium silicide layer, forms a solderable interface. Lead-tin solder on the nickel provides conductivity and allows a convenient means for interconnection of cells. To apply this metallization, three chemical plating baths are employed.

  16. Evanescent field phase shifting in a silicon nitride waveguide using a coupled silicon slab

    DEFF Research Database (Denmark)

    Jensen, Asger Sellerup; Oxenløwe, Leif Katsuo; Green, William M. J.

    2015-01-01

    An approach for electrical modulation of low-loss silicon nitride waveguides is proposed, using a silicon nitride waveguide evanescently loaded with a thin silicon slab. The thermooptic phase-shift characteristics are investigated in a racetrack resonator configuration.......An approach for electrical modulation of low-loss silicon nitride waveguides is proposed, using a silicon nitride waveguide evanescently loaded with a thin silicon slab. The thermooptic phase-shift characteristics are investigated in a racetrack resonator configuration....

  17. Derywaty z interfiksem -i- / -i/y- oraz pierwszym członem czasownikowym w języku serbskim, rosyjskim oraz polskim

    Directory of Open Access Journals (Sweden)

    Dragana Ratković

    2016-12-01

    formed by means of this derivational model is almost equally developed conceptually and relates predominantly to the same phenomena. Expressive words in all three languages are formed in the processes of metonymisation, metaphorisation, personification, hyperbolization and grotesque, and are characterized by numerous derivational and semantic equivalents.   Derywaty z interfiksem -i- / -i/y- oraz pierwszym członem czasownikowym w języku serbskim, rosyjskim oraz polskim Artykuł zawiera analizę historyczno-porównawczą wyrazów z interfiksem -i- / -i/y- oraz pierwszym członem czasownikowym (modelu A (czas. + -i- / -i/y- + B w języku serbskim, rosyjskim oraz polskim z punktu widzenia współczesnej derywatologii slawistycznej. Celem badań jest opis analizowanych derywatów według ich zróżnicowania znaczeniowego. Autorka wykazuje, że we wszystkich trzech językach według tego modelu słowotwórczego powstaje przede wszystkim słownictwo ekspresywne, głównie rzeczowniki, o znaczeniu żartobliwym i pejoratywnym. Taki typ wyrazów w języku serbskim i rosyjskim pojawia się po raz pierwszy w źródłach z XIII wieku (możliwe, że w serbskim już w XI w., natomiast w polszczyźnie w przebadanym materiale z XV wieku. Sądząc po źródłach, model słowotwórczy, według którego tworzone są analizowane wyrazy, jest produktywny we wszystkich trzech językach, zarówno w ich stadium historycznym, jak i w języku współczesnym, przy czym w języku serbskim i polskim jest takich derywatów więcej niż w języku rosyjskim. W źródłach sprzed XIX stulecia w języku serbskim i rosyjskim odnotowano głównie imiona i przydomki przetworzone w nazwiska (w języku rosyjskim również pewne nazwy zwierząt i roślin oraz rzeczowniki abstrakcyjne. W staropolszczyźnie jest to leksyka zoologiczna i botaniczna, а w dobie średniopolskiej wyrazy modelu A (czas. + -i/y- + B obejmują prawie wszystkie kategorie pojęciowe, do których przynależą wyrazy tego

  18. Annealing of silicon optical fibers

    Science.gov (United States)

    Gupta, N.; McMillen, C.; Singh, R.; Podila, R.; Rao, A. M.; Hawkins, T.; Foy, P.; Morris, S.; Rice, R.; Poole, K. F.; Zhu, L.; Ballato, J.

    2011-11-01

    The recent realization of silicon core optical fibers has the potential for novel low insertion loss rack-to-rack optical interconnects and a number of other uses in sensing and biomedical applications. To the best of our knowledge, incoherent light source based rapid photothermal processing (RPP) was used for the first time to anneal glass-clad silicon core optical fibers. X-ray diffraction examination of the silicon core showed a considerable enhancement in the length and amount of single crystallinity post-annealing. Further, shifts in the Raman frequency of the silicon in the optical fiber core that were present in the as-drawn fibers were removed following the RPP treatment. Such results indicate that the RPP treatment increases the local crystallinity and therefore assists in the reduction of the local stresses in the core, leading to more homogenous fibers. The dark current-voltage characteristics of annealed silicon optical fiber diodes showed lower leakage current than the diodes based on as-drawn fibers. Photons in UV and vacuum ultraviolet (VUV) regions play a very important role in improving the bulk and carrier transport properties of RPP-treated silicon optical fibers, and the resultant annealing permits a path forward to in situ enhancement of the structure and properties of these new crystalline core optical fibers.

  19. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jarillo-Herrero, Pablo [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-02-07

    This is the final report of our research program on electronic transport experiments on Topological Insulator (TI) devices, funded by the DOE Office of Basic Energy Sciences. TI-based electronic devices are attractive as platforms for spintronic applications, and for detection of emergent properties such as Majorana excitations , electron-hole condensates , and the topological magneto-electric effect . Most theoretical proposals envision geometries consisting of a planar TI device integrated with materials of distinctly different physical phases (such as ferromagnets and superconductors). Experimental realization of physics tied to the surface states is a challenge due to the ubiquitous presence of bulk carriers in most TI compounds as well as degradation during device fabrication.

  20. Optical properties of silicon germanium waveguides at telecommunication wavelengths.

    Science.gov (United States)

    Hammani, Kamal; Ettabib, Mohamed A; Bogris, Adonis; Kapsalis, Alexandros; Syvridis, Dimitris; Brun, Mickael; Labeye, Pierre; Nicoletti, Sergio; Richardson, David J; Petropoulos, Periklis

    2013-07-15

    We present a systematic experimental study of the linear and nonlinear optical properties of silicon-germanium (SiGe) waveguides, conducted on samples of varying cross-sectional dimensions and Ge concentrations. The evolution of the various optical properties for waveguide widths in the range 0.3 to 2 µm and Ge concentrations varying between 10 and 30% is considered. Finally, we comment on the comparative performance of the waveguides, when they are considered for nonlinear applications at telecommunications wavelengths.

  1. Direct Production of Silicones From Sand

    Energy Technology Data Exchange (ETDEWEB)

    Larry N. Lewis; F.J. Schattenmann: J.P. Lemmon

    2001-09-30

    Silicon, in the form of silica and silicates, is the second most abundant element in the earth's crust. However the synthesis of silicones (scheme 1) and almost all organosilicon chemistry is only accessible through elemental silicon. Silicon dioxide (sand or quartz) is converted to chemical-grade elemental silicon in an energy intensive reduction process, a result of the exceptional thermodynamic stability of silica. Then, the silicon is reacted with methyl chloride to give a mixture of methylchlorosilanes catalyzed by cooper containing a variety of tract metals such as tin, zinc etc. The so-called direct process was first discovered at GE in 1940. The methylchlorosilanes are distilled to purify and separate the major reaction components, the most important of which is dimethyldichlorosilane. Polymerization of dimethyldichlorosilane by controlled hydrolysis results in the formation of silicone polymers. Worldwide, the silicones industry produces about 1.3 billion pounds of the basic silicon polymer, polydimethylsiloxane.

  2. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-01-01

    with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  3. Silicon Photomultiplier charaterization

    Science.gov (United States)

    Munoz, Leonel; Osornio, Leo; Para, Adam

    2014-03-01

    Silicon Photo Multiples (SiPM's) are relatively new photon detectors. They offer many advantages compared to photo multiplier tubes (PMT's) such as insensitivity to magnetic field, robustness at varying lighting levels, and low cost. The SiPM output wave forms are poorly understood. The experiment conducted collected waveforms of responses of Hamamatsu SiPM to incident laser pulse at varying temperatures and bias voltages. Ambient noise was characterized at all temperatures and bias voltages by averaging the waveforms. Pulse shape of the SiPM response was determined under different operating conditions: the pulse shape is nearly independent of the bias voltage but exhibits strong variation with temperature, consistent with the temperature variation of the quenching resistor. Amplitude of responses of the SiPM to low intensity laser light shows many peaks corresponding to the detection of 1,2,3 etc. photons. Amplitude of these pulses depends linearly on the bias voltage, enabling determination of the breakdown voltage at each temperature. Poisson statistics has been used to determine the average number of detected photons at each operating conditions. Department of Education Grant No. P0315090007 and the Department of Energy/ Fermi National Accelerator Laboratory.

  4. Silicon Carbide Growth

    Science.gov (United States)

    2005-01-01

    Andrew Trunek has focused on supporting the Sic team through the growth of Sic crystals, making observations and conducting research that meets the collective needs and requirements of the team while fulfilling program commitments. Cancellation of the Ultra Efficient Engine Technology (UEET) program has had a significant negative impact on resources and research goals. This report highlights advancements and achievements made with this cooperative agreement over the past year. NASA Glenn Research Center (GRC) continues to make advances in silicon carbide (SiC) research during the past year. Step free surfaces were used as substrates for the deposition of GaN epilayers that yielded very low dislocation densities. Defect free 3C- SiC was successfully nucleated on step free mesas and test diodes were fabricated. Web growth techniques were used to increase the usable surface area of dislocation free SiC by approximately equal to 40%. The greatest advancement has been attained on stepped surfaces of SiC. A metrology standard was developed using high temperature etching techniques titled "Nanometer Step Height Standard". This development culminated in being recognized for a 2004 R&D100 award and the process to produce the steps received a NASA Space Act award.

  5. Collimation: a silicon solution

    CERN Multimedia

    2007-01-01

    Silicon crystals could be used very efficiently to deflect high-energy beams. Testing at CERN has produced conclusive results, which could pave the way for a new generation of collimators. The set of five crystals used to test the reflection of the beams. The crystals are 0.75 mm wide and their alignment is adjusted with extreme precision. This figure shows the deflection of a beam by channelling and by reflection in the block of five crystals. Depending on the orientation of the crystals: 1) The beam passes without "seeing" the crystals and is not deflected 2) The beam is deflected by channelling (with an angle of around 100 μrad) 3) The beam is reflected (with an angle of around 50 μrad). The intensity of the deflected beam is illustrated by the intensity of the spot. The spot of the reflected beam is clearly more intense than that one of the channelled beam, demonstrating the efficiency of t...

  6. Jak różnicować wymioty u noworodków i niemowląt? Część IV. Metaboliczne, endokrynologiczne i sercowo-naczyniowe przyczyny wymiotów

    OpenAIRE

    Zbigniew Krenc

    2014-01-01

    Wymioty u niemowląt są często obserwowanym objawem chorobowym, o bardzo zróżnicowanym podłożu patogenetycznym. Do rzadkich przyczyn wymiotów w tej grupie wiekowej należą choroby metaboliczne i endokrynologiczne, a wyjątkowo także schorzenia układu sercowo-naczyniowego. Do chorób metabolicznych przebiegających ze zwracaniem pokarmu należą zaburzenia metabolizmu białek, m.in. fenyloketonuria, leucynoza, zaburzenia cyklu mocznikowego i kwasice organiczne. Wymioty w zaburzeniach metab...

  7. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Robert C. [Texas A& M University; Kamon, Teruki [Texas A& M University; Toback, David [Texas A& M University; Safonov, Alexei [Texas A& M University; Dutta, Bhaskar [Texas A& M University; Dimitri, Nanopoulos [Texas A& M University; Pope, Christopher [Texas A& M University; White, James [Texas A& M University

    2013-11-18

    Overview The High Energy Physics Group at Texas A&M University is submitting this final report for our grant number DE-FG02-95ER40917. This grant has supported our wide range of research activities for over a decade. The reports contained here summarize the latest work done by our research team. Task A (Collider Physics Program): CMS & CDF Profs. T. Kamon, A. Safonov, and D. Toback co-lead the Texas A&M (TAMU) collider program focusing on CDF and CMS experiments. Task D: Particle Physics Theory Our particle physics theory task is the combined effort of Profs. B. Dutta, D. Nanopoulos, and C. Pope. Task E (Underground Physics): LUX & NEXT Profs. R. Webb and J. White(deceased) lead the Xenon-based underground research program consisting of two main thrusts: the first, participation in the LUX two-phase xenon dark matter search experiment and the second, detector R&D primarily aimed at developing future detectors for underground physics (e.g. NEXT and LZ).

  8. Tests of timing properties of silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Ronzhin, A.; Albrow, M.; /Fermilab; Byrum, K.; /Argonne; Demarteau, M.; Los, S.; /Fermilab; May, E.; /Argonne; Ramberg, A.; /Fermilab; Va' vra, J.; /SLAC; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

    2010-03-01

    Timing measurements of Silicon Photomultipliers (SiPM) [1] and [2] at the picosecond level were performed at Fermilab. The core timing resolution of the electronic measurement technique is approximately 2 ps. The single photoelectron time resolution (SPTR) was measured for the signals coming from the SiPM's. A SPTR of about one hundred picoseconds was obtained for SiPM's illuminated by laser pulses. The dependence of the SPTR on applied bias voltage and on the wavelength of the light was measured. A simple model is proposed to explain the difference in the SPTR for blue and red light. A time of flight system based on the SiPM's, with quartz Cherenkov radiators, was tested in a proton beam at Fermilab. The time resolution obtained is 35 ps per SiPM. Finally, requirements for the SiPM's temperature and bias voltage stability to maintain the time resolution are discussed.

  9. Multivariate data analysis of process control data from neutron transmutation doping of silicon

    DEFF Research Database (Denmark)

    Heydorn, K.; Hegaard, N.

    1994-01-01

    Final resistivities obtained by neutron transmutation doping (NTD) of silicon can be measured only after an annealing process has been carried out at the manufacturer's plant. The reactor centre carrying out the neutron doping process by irradiation under selected conditions must control the proc...... the process by indirect measurement of the product quality. The method of partial least squares was used to identify important parameters for improving the quality of the NTD-silicon, as well as for predicting the final quality data observed by the customer.......Final resistivities obtained by neutron transmutation doping (NTD) of silicon can be measured only after an annealing process has been carried out at the manufacturer's plant. The reactor centre carrying out the neutron doping process by irradiation under selected conditions must control...

  10. Silicon PM Radiation Hardness

    Energy Technology Data Exchange (ETDEWEB)

    Rohlf, James [Boston Univ., MA (United States)

    2016-08-25

    Detailed measurements have been made of 9 mm2 SiPMs from Hamamatsu (MPPC) and Zecotek (MAPD) after room temperature annealing after exposure to fluences of 1012 to 1013 cm-2. The data was used to complete the final ADR report.

  11. Polycystalline silicon thin films for electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Christian Claus

    2012-01-15

    with an activation energy of E{sub A}{sup poly-Si}=1.1 eV. By long-lasting tempering or a short high-temperature step finally the stable layer configuration substrate/Al+Si islands(hillocks)/poly-Si can be reached (E{sub A}{sup hillocks}=2.4 eV). The further main topic of this thesis is the study of the applicability of the poly-silicon layers fabricated by means of the ALILE and R-ALILE process for electronic applications. First thin-film transistors were studied. Additionally thin-film solar cells with microcrystalline silicon as absorber material on polycrystalline R-ALILE seed layers were fabricated. Finally the suitedness of the fabricated poly-silicon layers for crytographic applications were studied.

  12. Silicon nitride equation of state

    Science.gov (United States)

    Brown, Robert C.; Swaminathan, Pazhayannur K.

    2017-01-01

    This report presents the development of a global, multi-phase equation of state (EOS) for the ceramic silicon nitride (Si3N4).1 Structural forms include amorphous silicon nitride normally used as a thin film and three crystalline polymorphs. Crystalline phases include hexagonal α-Si3N4, hexagonal β-Si3N4, and the cubic spinel c-Si3N4. Decomposition at about 1900 °C results in a liquid silicon phase and gas phase products such as molecular nitrogen, atomic nitrogen, and atomic silicon. The silicon nitride EOS was developed using EOSPro which is a new and extended version of the PANDA II code. Both codes are valuable tools and have been used successfully for a variety of material classes. Both PANDA II and EOSPro can generate a tabular EOS that can be used in conjunction with hydrocodes. The paper describes the development efforts for the component solid phases and presents results obtained using the EOSPro phase transition model to investigate the solid-solid phase transitions in relation to the available shock data that have indicated a complex and slow time dependent phase change to the c-Si3N4 phase. Furthermore, the EOSPro mixture model is used to develop a model for the decomposition products; however, the need for a kinetic approach is suggested to combine with the single component solid models to simulate and further investigate the global phase coexistences.

  13. Nanocrystalline silicon in biological studies

    Energy Technology Data Exchange (ETDEWEB)

    Fucikova, Anna [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2 (Czech Republic); Institute of Physics AS CR, v. v. i., Cukrovarnicka 10, 162 53 Prague 6 (Czech Republic); Valenta, Jan [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2 (Czech Republic); Pelant, Ivan; Kusova, Katerina [Institute of Physics AS CR, v. v. i., Cukrovarnicka 10, 162 53 Prague 6 (Czech Republic); Brezina, Vitezslav [Institute of Systems Biology and Ecology AS CR, v. v. i., Zamek 136, 373 33 Nove Hrady (Czech Republic)

    2011-03-15

    Porous silicon and similar materials, like micro- and nanocrystalline silicon, are nowadays studied not only in physical research (e.g. optical gain studies, electro-optical devices, solar energy conversion), but they are very promising also in biological research as fluorescent labels, biological sensors, drug delivery systems or scaffold for various tissues. We are giving an overview of various approaches of preparation of micro- and nanocrystalline silicon and current studies of applications with main focus on biology and medicine. In contrast to other nanomaterials used in biological studies (e.g. carbon nanotubes, fullerenes, cadmium containing quantum dots) silicon based nanomaterials show very good biocompatibility and low cytotoxicity. Therefore, these materials have potential to become powerful tools for in vivo investigation of life processes on subcellular and molecular level. Our group concentrates on developing of gentle fluorescent label based on porous silicon for single molecule detection in the cell. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. H2 sensing properties of modified silicon nanowires

    Directory of Open Access Journals (Sweden)

    Latefa Baba Ahmed

    2015-04-01

    Full Text Available It has been found that the silicon nanowires modified with noble metals can be used to fabricate an effective H2 gas sensor in the present study. The preparation and surface modification of silicon nanowires (SiNWs were carried out by chemical methods. The morphology of the silicon nanowires unmodified and modified with nanoparticles of platinum, palladium, silver and gold was investigated using scanning electron microscopy (SEM. The chemical composition of the silicon nanowire layers was studied by secondary ion mass spectroscopy (SIMS and energy dispersive X-ray analysis (EDX. The structures of type metal/SiNWs/p-Si/Al were fabricated. The electrical characterization (I–V was performed in primary vacuum and H2 at different concentrations. It was found that the metal type used to modify the SiNWs strongly influenced the I–V characteristics. The response of these structures toward H2 gas was studied as a function of the metal type. Finally, the sensing characteristics and performance of the sensors were investigated.

  15. Lithium ion irradiation of standard and oxygenated silicon diodes

    CERN Document Server

    Candelori, A; Bisello, D; Giubilato, P; Kaminski, A; Litovchenko, A P; Lozano, A; Petrie, J R; Rando, R; Ullán, M; Wyss, J

    2004-01-01

    The next generation silicon detectors for future very high luminosity colliders or a possible LHC upgrade scenario will require radiation- hard detectors for fluences up to 10/sup 16/ 1-MeV equivalent neutrons/cm/sup 2/. These high fluences present strong constraints because long irradiation times are required at the currently available proton irradiation facilities. Energetic (58 MeV) lithium ions present a non-ionizing energy loss approximately=27.3 times higher than 27 MeV protons, and could consequently be a new promising radiation source for investigating the radiation hardness of silicon detectors up to very high particle fluences. Starting from this premise, we have investigated the degradation, as measured by the leakage current density increase and depletion voltage variations in the short and long-term characteristics, induced by 58 MeV Li ions in state-of-the-art silicon diodes processed by two different manufacturers on standard and oxygenated silicon substrates. Finally, the correlation between t...

  16. Tin oxide - silicon dioxide - silicon MIS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Llabres, K.; Dominguez, E.; Lora-Tamayo, E.; Arjona, F.

    1981-01-01

    The results obtained in tin oxide-silicon dioxide-n type silicon Schottky barrier solar cells are presented. Samples were prepared in a two-zone furnace where the thermal oxidation of the wafer and the SnO/sub 2/ deposition were carried out without further handling. The tin oxide layer was grown using a gas transport method in an open tube. The characteristic parameters of the solar cell performance gave the following results: short circuit current density.21 mA/cm/sup 2/, open circuit voltage.550 mV. 7 refs.

  17. Search for microscopic black holes in a like-sign dimuon final state using large track multiplicity with the ATLAS detector

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lysák, Roman; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Vrba, Václav

    2013-01-01

    Roč. 88, č. 7 (2013), "072001-1"-"072001-22" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : tracks * multiplicity * final state * dimuon * same sign * black hole * mass * gravitation * model * ATLAS * CERN LHC Coll * background Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.864, year: 2013

  18. Back-contacted back-junction silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mangersnes, Krister

    2010-10-15

    have developed a two-dimensional BC-BJ silicon solar cell device model. The simulations, which are based on the finite element method, have been performed with the ATLAS device simulator within the Silvaco simulation framework from Silvaco Inc., USA. The device model has been used to optimize the design of a BC-BJ silicon solar cell based on experimental results obtained during the work with this thesis. The model is able to quantitatively predict the performance of cells with different designs, qualities, and dimensions through optical and electrical simulations, and thereby giving us a good indication of the efficiency potential of the cell structure. It has also given us valuable insight into the physics determining the performance of a BC-BJ silicon solar cell. From this insight, important conclusions regarding the design rules of this type of solar cell devices could be drawn. Finally, the device model was used to investigate quantum mechanical tunneling mechanisms in the junction between the adjacent, highly-doped regions of opposite polarity on the backside of the cell. Through the simulations we found some simple design rules that need to be followed in order to avoid shunting-like behavior due to unwanted trap-assisted tunneling in the lateral tunneling junction. At the same time, band-to-band tunneling entails potential current breakdowns at low to moderate reverse biases. This implies that local hot-spots can be avoided since the heat distribution under reverse bias will be distributed throughout the whole junction area. Thus, by careful optimization and tailoring of the doping profiles, the tunneling may enable the use of back-junction silicon solar cells in a solar module without the need for bypass diodes. (Author)

  19. Silicon Nitride Bearings for Total Joint Arthroplasty

    National Research Council Canada - National Science Library

    McEntire, Bryan; Lakshminarayanan, Ramaswamy; Ray, Darin; Clarke, Ian; Puppulin, Leonardo; Pezzotti, Giuseppe

    2016-01-01

      The articulation performance of silicon nitride against conventional and highly cross-linked polyethylene, as well as for self-mated silicon nitride bearings, was examined in a series of standard hip simulation studies...

  20. SILICON REFINING BY VACUUM TREATMENT

    Directory of Open Access Journals (Sweden)

    André Alexandrino Lotto

    2014-12-01

    Full Text Available This work aims to investigate the phosphorus removal by vacuum from metallurgical grade silicon (MGSi (98.5% to 99% Si. Melting experiments were carried out in a vacuum induction furnace, varying parameters such as temperature, time and relation area exposed to the vacuum / volume of molten silicon. The results of chemical analysis were obtained by inductively coupled plasma (ICP, and evaluated based on thermodynamic and kinetic aspects of the reaction of vaporization of the phosphorus in the silicon. The phosphorus was decreased from 33 to approximately 1.5 ppm after three hours of vacuum treatment, concluding that the evaporation step is the controlling step of the process for parameters of temperature, pressure and agitation used and refining by this process is technically feasible.

  1. A silicon tracker for Christmas

    CERN Multimedia

    2008-01-01

    The CMS experiment installed the world’s largest silicon tracker just before Christmas. Marcello Mannelli: physicist and deputy CMS project leader, and Alan Honma, physicist, compare two generations of tracker: OPAL for the LEP (at the front) and CMS for the LHC (behind). There is quite a difference between 1m2 and 205m2.. CMS received an early Christmas present on 18 December when the silicon tracker was installed in the heart of the CMS magnet. The CMS tracker team couldn’t have hoped for a better present. Carefully wrapped in shiny plastic, the world’s largest silicon tracker arrived at Cessy ready for installation inside the CMS magnet on 18 December. This rounded off the year for CMS with a major event, the crowning touch to ten years of work on the project by over five hundred scientists and engineers. "Building a scientific instrument of this size and complexity is a huge technical a...

  2. 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.

  3. Silicon-Light: a European project aiming at high efficiency thin film silicon solar cells on foil

    Directory of Open Access Journals (Sweden)

    Soppe W.

    2014-07-01

    Full Text Available In the European project Silicon-Light we developed concepts and technologies to increase conversion efficiencies of thin film silicon solar cells on foil. Main focus was put on improved light management, using NIL for creating light scattering textures, improved TCOs using sputtering, and improved silicon absorber material made by PECVD. On foil we achieved initial cell efficiencies of 11% and on rigid substrates stable efficiencies of 11.6% were achieved. Finally, the project demonstrated the industrial scale feasibility of the developed technologies and materials. Cost of ownership calculations showed that implementation of these technologies on large scale would enable the production of these high efficiency solar modules at manufacturing cost of 0.65 €/Wp with encapsulation costs (0.20 €/Wp being the dominant costs. Life cycle analysis showed that large scale production of modules based on the technologies developed in Silicon-Light would have an energy payback time of 0.85 years in Central European countries.

  4. Semiconducting silicon nanowires for biomedical applications

    CERN Document Server

    Coffer, JL

    2014-01-01

    Biomedical applications have benefited greatly from the increasing interest and research into semiconducting silicon nanowires. Semiconducting Silicon Nanowires for Biomedical Applications reviews the fabrication, properties, and applications of this emerging material. The book begins by reviewing the basics, as well as the growth, characterization, biocompatibility, and surface modification, of semiconducting silicon nanowires. It goes on to focus on silicon nanowires for tissue engineering and delivery applications, including cellular binding and internalization, orthopedic tissue scaffol

  5. Energy Harvesting from Energetic Porous Silicon

    Science.gov (United States)

    2016-07-01

    wafers backed with platinum are patterned into 2- mm devices with bridge wires (Fig. 1 [left]). Using a silicon nitride layer as a mask, the silicon is...ARL-TR-7719 ● JULY 2016 US Army Research Laboratory Energy Harvesting from Energetic Porous Silicon by Louis B Levine, Matthew...Harvesting from Energetic Porous Silicon by Louis B Levine Academy of Applied Science, Concord, NH Matthew H Ervin and Wayne A Churaman Sensors and

  6. Silicon Photonics Cloud (SiCloud)

    DEFF Research Database (Denmark)

    DeVore, P. T. S.; Jiang, Y.; Lynch, M.

    2015-01-01

    Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths.......Silicon Photonics Cloud (SiCloud.org) is the first silicon photonics interactive web tool. Here we report new features of this tool including mode propagation parameters and mode distribution galleries for user specified waveguide dimensions and wavelengths....

  7. Silicon nanocrystal inks, films, and methods

    Science.gov (United States)

    Wheeler, Lance Michael; Kortshagen, Uwe Richard

    2015-09-01

    Silicon nanocrystal inks and films, and methods of making and using silicon nanocrystal inks and films, are disclosed herein. In certain embodiments the nanocrystal inks and films include halide-terminated (e.g., chloride-terminated) and/or halide and hydrogen-terminated nanocrystals of silicon or alloys thereof. Silicon nanocrystal inks and films can be used, for example, to prepare semiconductor devices.

  8. Silicon Based Mid Infrared SiGeSn Heterostructure Emitters and Detectors

    Science.gov (United States)

    2016-05-16

    AFRL-AFOSR-JP-TR-2016-0054 Silicon based mid infrared SiGeSn heterostrcture emitters and detectors Greg Sun UNIVERSITY OF MASSACHUSETTS Final Report...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD- MM -YYYY)      16-05-2016 2. REPORT...TYPE Final 3. DATES COVERED (From - To) 17 Jun 2014 to 16 Dec 2015 4. TITLE AND SUBTITLE Silicon based mid infrared SiGeSn heterostrcture emitters and

  9. Silicon sources for rice crop

    Directory of Open Access Journals (Sweden)

    Pereira Hamilton Seron

    2004-01-01

    Full Text Available Although silicon is not an essential nutrient, its application is beneficial for plant growth and development. To evaluate silicon sources in relation to agronomic efficiency and economic viability in rice crops (Oryza sativa L., a greenhouse experiment was conducted, Quartzipsamment soil, in a completely randomized experimental design (n = 4. Treatments were 12 silicon sources and a control. Silicon was applied at the rate of 125 kg Si ha-1. Data were compared to a standard response curve for Si using the standard source Wollastonite at rates of 0, 125, 250, 375, and 500 kg Si ha-1. All treatments received CaCO3 and MgCO3 to balance pH, Ca and Mg. One hundred and fifty days after sowing, evaluations on dry matter yield in the above-ground part of plants, grain yield, and Si contents in the soil and plant tissues were performed. Wollastonite had linear response, increasing silicon in the soil and plants with increasing application rates. Differences between silicon sources in relation to Si uptake were observed. Phosphate slag provided the highest Si uptake, followed by Wollastonite and electric furnace silicates which however, did not show differed among themselves. The highest Si accumulation in grain was observed for stainless steel, which significantly differed from the control, silicate clay, Wollastonite, and AF2 (blast furnace of the company 2 slag. Silicate clay showed the lowest Si accumulation in grain and did not differ from the control, AF2 slag, AF1 slag, schist ash, schist, and LD4 (furnace steel type LD of the company 4 slag.

  10. Laser wafering for silicon solar.

    Energy Technology Data Exchange (ETDEWEB)

    Friedmann, Thomas Aquinas; Sweatt, William C.; Jared, Bradley Howell

    2011-03-01

    Current technology cuts solar Si wafers by a wire saw process, resulting in 50% 'kerf' loss when machining silicon from a boule or brick into a wafer. We want to develop a kerf-free laser wafering technology that promises to eliminate such wasteful wire saw processes and achieve up to a ten-fold decrease in the g/W{sub p} (grams/peak watt) polysilicon usage from the starting polysilicon material. Compared to today's technology, this will also reduce costs ({approx}20%), embodied energy, and green-house gas GHG emissions ({approx}50%). We will use short pulse laser illumination sharply focused by a solid immersion lens to produce subsurface damage in silicon such that wafers can be mechanically cleaved from a boule or brick. For this concept to succeed, we will need to develop optics, lasers, cleaving, and high throughput processing technologies capable of producing wafers with thicknesses < 50 {micro}m with high throughput (< 10 sec./wafer). Wafer thickness scaling is the 'Moore's Law' of silicon solar. Our concept will allow solar manufacturers to skip entire generations of scaling and achieve grid parity with commercial electricity rates. Yet, this idea is largely untested and a simple demonstration is needed to provide credibility for a larger scale research and development program. The purpose of this project is to lay the groundwork to demonstrate the feasibility of laser wafering. First, to design and procure on optic train suitable for producing subsurface damage in silicon with the required damage and stress profile to promote lateral cleavage of silicon. Second, to use an existing laser to produce subsurface damage in silicon, and third, to characterize the damage using scanning electron microscopy and confocal Raman spectroscopy mapping.

  11. Vertical integration of high-Q silicon nitride microresonators into silicon-on-insulator platform.

    Science.gov (United States)

    Li, Qing; Eftekhar, Ali A; Sodagar, Majid; Xia, Zhixuan; Atabaki, Amir H; Adibi, Ali

    2013-07-29

    We demonstrate a vertical integration of high-Q silicon nitride microresonators into the silicon-on-insulator platform for applications at the telecommunication wavelengths. Low-loss silicon nitride films with a thickness of 400 nm are successfully grown, enabling compact silicon nitride microresonators with ultra-high intrinsic Qs (~ 6 × 10(6) for 60 μm radius and ~ 2 × 10(7) for 240 μm radius). The coupling between the silicon nitride microresonator and the underneath silicon waveguide is based on evanescent coupling with silicon dioxide as buffer. Selective coupling to a desired radial mode of the silicon nitride microresonator is also achievable using a pulley coupling scheme. In this work, a 60-μm-radius silicon nitride microresonator has been successfully integrated into the silicon-on-insulator platform, showing a single-mode operation with an intrinsic Q of 2 × 10(6).

  12. Polyelectrolyte multilayer-assisted fabrication of non-periodic silicon nanocolumn substrates for cellular interface applications

    Science.gov (United States)

    Lee, Seyeong; Kim, Dongyoon; Kim, Seong-Min; Kim, Jeong-Ah; Kim, Taesoo; Kim, Dong-Yu; Yoon, Myung-Han

    2015-08-01

    Recent advances in nanostructure-based biotechnology have resulted in a growing demand for vertical nanostructure substrates with elaborate control over the nanoscale geometry and a high-throughput preparation. In this work, we report the fabrication of non-periodic vertical silicon nanocolumn substrates via polyelectrolyte multilayer-enabled randomized nanosphere lithography. Owing to layer-by-layer deposited polyelectrolyte adhesives, uniformly-separated polystyrene nanospheres were securely attached on large silicon substrates and utilized as masks for the subsequent metal-assisted silicon etching in solution. Consequently, non-periodic vertical silicon nanocolumn arrays were successfully fabricated on a wafer scale, while each nanocolumn geometric factor, such as the diameter, height, density, and spatial patterning, could be fully controlled in an independent manner. Finally, we demonstrate that our vertical silicon nanocolumn substrates support viable cell culture with minimal cell penetration and unhindered cell motility due to the blunt nanocolumn morphology. These results suggest that vertical silicon nanocolumn substrates may serve as a useful cellular interface platform for performing a statistically meaningful number of cellular experiments in the fields of biomolecular delivery, stem cell research, etc.Recent advances in nanostructure-based biotechnology have resulted in a growing demand for vertical nanostructure substrates with elaborate control over the nanoscale geometry and a high-throughput preparation. In this work, we report the fabrication of non-periodic vertical silicon nanocolumn substrates via polyelectrolyte multilayer-enabled randomized nanosphere lithography. Owing to layer-by-layer deposited polyelectrolyte adhesives, uniformly-separated polystyrene nanospheres were securely attached on large silicon substrates and utilized as masks for the subsequent metal-assisted silicon etching in solution. Consequently, non-periodic vertical

  13. High-End Silicon PDICs

    Directory of Open Access Journals (Sweden)

    H. Zimmermann

    2008-05-01

    Full Text Available An overview on integrated silicon photodiodes and photodiode integrated circuits (PDICs or optoelectronic integrated circuits (OEICs for optical storage systems (OSS and fiber receivers is given. It is demonstrated, that by using low-cost silicon technologies high-performance OEICs being true competitors for some III/V-semiconductor OEICs can be realized. OSS-OEICs with bandwidths of up to 380 MHz and fiber receivers with maximum data rates of up to 11 Gbps are described. Low-cost data comm receivers for plastic optical fibers (POF as well as new circuit concepts for OEICs and highly parallel optical receivers are described also in the following.

  14. Microdefects in cast multicrystalline silicon

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, E.; Klinger, D.; Bergmann, S. [Inst. of Crystal Growth Berlin (Germany)

    1995-08-01

    The microdefect etching behavior of cast multicrystalline BAYSIX and SILSO samples is mainly the same as that of EFG silicon, in spite of the very different growth parameters applied to these two techniques and the different carbon contents of the investigated materials. Intentional decorating of mc silicon with copper, iron and gold did not influence the results of etching and with help of infrared transmission microscopy no metal precipitates at the assumed microdefects could be established. There are many open questions concerning the origin of the assumed, not yet doubtless proved microdefects.

  15. Advancements in silicon web technology

    Science.gov (United States)

    Hopkins, R. H.; Easoz, J.; Mchugh, J. P.; Piotrowski, P.; Hundal, R.

    1987-01-01

    Low defect density silicon web crystals up to 7 cm wide are produced from systems whose thermal environments are designed for low stress conditions using computer techniques. During growth, the average silicon melt temperature, the lateral melt temperature distribution, and the melt level are each controlled by digital closed loop systems to maintain thermal steady state and to minimize the labor content of the process. Web solar cell efficiencies of 17.2 pct AM1 have been obtained in the laboratory while 15 pct efficiencies are common in pilot production.

  16. A silicon microstrip gas chamber

    Energy Technology Data Exchange (ETDEWEB)

    Van der Marel, J. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Van den Bogaard, A. (Delft Inst. of Microelectronics and Submicrotechnology, Delft Univ. of Tech. (Netherlands)); Van Eijk, C.W.E. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Hollander, R.W. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Okx, W.J.C. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Sarro, P.M. (Delft Inst. of Microelectronics and Submicrotechnology, Delft Univ. of Tech. (Netherlands))

    1994-09-01

    We are manufacturing microstrip gas chambers (MSGC) on silicon with an insulating SiO[sub 2] layer. To study the effect of the sheet resistance of the SiO[sub 2] on the operation of the detector several processes to modify the SiO[sub 2] layer have been investigated: ion implantation, boron and phosphorus diffusion, phosphosilicate glass evaporation and polycrystalline silicon deposition. The dependence of the gas gain on the potentials of the different electrodes and the long term stability have been studied. ((orig.))

  17. Extrinsic doping in silicon revisited

    KAUST Repository

    Schwingenschlögl, Udo

    2010-06-17

    Both n-type and p-type doping of silicon is at odds with the charge transfer predicted by Pauling electronegativities and can only be reconciled if we no longer regarding dopant species as isolated atoms but rather consider them as clusters consisting of the dopant and its four nearest neighbor silicon atoms. The process that gives rise to n-type and p-type effects is the charge redistribution that occurs between the dopant and its neighbors, as we illustrate here using electronic structure calculations. This view point is able to explain why conventional substitutional n-type doping of carbon has been so difficult.

  18. Radiation effects in bulk silicon

    Science.gov (United States)

    Claeys, Cor; Vanhellemont, Jan

    1994-01-01

    This paper highlights important aspects related to irradiation effects in bulk silicon. Some basic principles related to the interaction of radiation with material, i.e. ionization and atomic displacement, are briefly reviewed. A physical understanding of radiation effects strongly depends on the availability of appropriate analytical tools. These tools are critically accessed from a silicon bulk viewpoint. More detailed information, related to the properties of the bulk damage and some dedicated application aspects, is given for both electron and proton irradiations. Emphasis is placed on radiation environments encountered during space missions and on their influence on the electrical performance of devices such as memories and image sensors.

  19. Silicon Nano-Photonic Devices

    DEFF Research Database (Denmark)

    Pu, Minhao

    to microwave systems and biosensing devices. An ultra-low loss inverse taper coupler for interfacing silicon ridge waveguides and optical bers is introduced and insertion losses of less than 1 dB are achieved for both transverse-electric (TE) and transversemagnetic (TM) polarizations. Integrated...... with the couplers, a silicon ridge waveguide is utilized in nonlinear all-optical signal processing for optical time division multiplexing (OTDM) systems. Record ultra-highspeed error-free optical demultiplexing and waveform sampling are realized and demonstrated for the rst time. Microwave phase shifters and notch...

  20. PECASE: New Directions for Silicon Integrated Optics

    Science.gov (United States)

    2013-04-30

    silicon microring resonators for label-free biosensing in undiluted human plasma,” Biosensors and Bioelectronics 42 (2013) A widely acknowledged...resonators as high sensitivity biosensors will be discussed. The results of the research including scientific publications and patents are...demonstrating mid-infrared integrated optics in silicon and pursuing new investigations into using silicon resonators as high sensitivity biosensors . A

  1. Surface Passivation for Silicon Heterojunction Solar Cells

    NARCIS (Netherlands)

    Deligiannis, D.

    2017-01-01

    Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type

  2. MITLL Silicon Integrated Photonics Process: Design Guide

    Science.gov (United States)

    2015-07-31

    MIT Lincoln Laboratory Silicon Integrated Photonics Process Design Guide Revision 2015:1a (31 July 2015) Comprehensive Design...Government. Rev.: 2015:1a (18 June 2015) i MITLL Silicon Integrated Photonics Process Comprehensive Design Guide ... Silicon Integrated Photonics Process Comprehensive Design Guide 16  Deep Etch for Fiber Coupling (DEEP_ETCH

  3. Silicon vertex detector for superheavy elements identification

    Directory of Open Access Journals (Sweden)

    Bednarek A.

    2012-07-01

    Full Text Available Silicon vertex detector for superheavy elements (SHE identification has been proposed. It will be constructed using very thin silicon detectors about 5 μm thickness. Results of test of 7.3 μm four inch silicon strip detector (SSD with fission fragments and α particles emitted by 252Cf source are presented

  4. Engineering piezoresistivity using biaxially strained silicon

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Richter, Jacob; Brandbyge, Mads

    2008-01-01

    of the piezocoefficient on temperature and dopant density is altered qualitatively for strained silicon. In particular, we find that a vanishing temperature coefficient may result for silicon with grown-in biaxial tensile strain. These results suggest that strained silicon may be used to engineer the iezoresistivity...

  5. ePIXfab - The silicon photonics platform

    NARCIS (Netherlands)

    Khanna, A.; Drissi, Y.; Dumon, P.; Baets, R.; Absil, P.; Pozo Torres, J.M.; Lo Cascio, D.M.R.; Fournier, M.; Fedeli, J.M.; Fulbert, L.; Zimmermann, L.; Tillack, B.; Aalto, T.; O'Brien, P.; Deptuck, D.; Xu, J.; Gale, D.

    2013-01-01

    ePIXfab-The European Silicon Photonics Support Center continues to provide state-of-the-art silicon photonics solutions to academia and industry for prototyping and research. ePIXfab is a consortium of EU research centers providing diverse expertise in the silicon photonics food chain, from training

  6. 21 CFR 573.940 - Silicon dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Silicon dioxide. 573.940 Section 573.940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Listing § 573.940 Silicon dioxide. The food additive silicon dioxide may be safely used in animal feed in...

  7. Analysis of silicon transporters in turfgrass species

    Science.gov (United States)

    Silicon is an abundant element on earth and is also known to be beneficial as an amendment in some crops such as rice. Despite its abundance in many soils, accumulation of silicon in plants is species-specific and can be widely different. It has been shown that the genes responsible for silicon upta...

  8. 21 CFR 172.480 - Silicon dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Silicon dioxide. 172.480 Section 172.480 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.480 Silicon dioxide. The food additive silicon dioxide may be safely used in food in...

  9. PECVD silicon nitride diaphragms for condenser microphones

    NARCIS (Netherlands)

    Scheeper, P.R.; Scheeper, P.R.; Voorthuyzen, J.A.; Voorthuyzen, J.A.; Bergveld, Piet

    1991-01-01

    The application of plasma-enhanced chemical vapour deposited (PECVD) silicon nitride as a diaphragm material for condenser microphones has been investigated. By means of adjusting the SiH4/NH3 gas-flow composition, silicon-rich silicon nitride films have been obtained with a relatively low tensile

  10. Aquaporins Mediate Silicon Transport in Humans.

    Science.gov (United States)

    Garneau, Alexandre P; Carpentier, Gabriel A; Marcoux, Andrée-Anne; Frenette-Cotton, Rachelle; Simard, Charles F; Rémus-Borel, Wilfried; Caron, Luc; Jacob-Wagner, Mariève; Noël, Micheline; Powell, Jonathan J; Bélanger, Richard; Côté, François; Isenring, Paul

    2015-01-01

    In animals, silicon is an abundant and differentially distributed trace element that is believed to play important biological functions. One would thus expect silicon concentrations in body fluids to be regulated by silicon transporters at the surface of many cell types. Curiously, however, and even though they exist in plants and algae, no such transporters have been identified to date in vertebrates. Here, we show for the first time that the human aquaglyceroporins, i.e., AQP3, AQP7, AQP9 and AQP10 can act as silicon transporters in both Xenopus laevis oocytes and HEK-293 cells. In particular, heterologously expressed AQP7, AQP9 and AQP10 are all able to induce robust, saturable, phloretin-sensitive silicon transport activity in the range that was observed for low silicon rice 1 (lsi1), a silicon transporter in plant. Furthermore, we show that the aquaglyceroporins appear as relevant silicon permeation pathways in both mice and humans based on 1) the kinetics of substrate transport, 2) their presence in tissues where silicon is presumed to play key roles and 3) their transcriptional responses to changes in dietary silicon. Taken together, our data provide new evidence that silicon is a potentially important biological element in animals and that its body distribution is regulated. They should open up original areas of investigations aimed at deciphering the true physiological role of silicon in vertebrates.

  11. 77 FR 20649 - Silicon Metal From China

    Science.gov (United States)

    2012-04-05

    ... COMMISSION Silicon Metal From China Determination On the basis of the record \\1\\ developed in the subject... order on silicon metal from China would be likely to lead to continuation or recurrence of material... Publication 4312 (March 2012), entitled Silicon Metal from China: Investigation No. 731-TA-472 (Third Review...

  12. Aquaporins Mediate Silicon Transport in Humans.

    Directory of Open Access Journals (Sweden)

    Alexandre P Garneau

    Full Text Available In animals, silicon is an abundant and differentially distributed trace element that is believed to play important biological functions. One would thus expect silicon concentrations in body fluids to be regulated by silicon transporters at the surface of many cell types. Curiously, however, and even though they exist in plants and algae, no such transporters have been identified to date in vertebrates. Here, we show for the first time that the human aquaglyceroporins, i.e., AQP3, AQP7, AQP9 and AQP10 can act as silicon transporters in both Xenopus laevis oocytes and HEK-293 cells. In particular, heterologously expressed AQP7, AQP9 and AQP10 are all able to induce robust, saturable, phloretin-sensitive silicon transport activity in the range that was observed for low silicon rice 1 (lsi1, a silicon transporter in plant. Furthermore, we show that the aquaglyceroporins appear as relevant silicon permeation pathways in both mice and humans based on 1 the kinetics of substrate transport, 2 their presence in tissues where silicon is presumed to play key roles and 3 their transcriptional responses to changes in dietary silicon. Taken together, our data provide new evidence that silicon is a potentially important biological element in animals and that its body distribution is regulated. They should open up original areas of investigations aimed at deciphering the true physiological role of silicon in vertebrates.

  13. Highly efficient silicon light emitting diode

    NARCIS (Netherlands)

    Le Minh, P.; Holleman, J.; Wallinga, Hans

    2002-01-01

    In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a

  14. Silicon carbide as platform for energy applications

    DEFF Research Database (Denmark)

    Syväjärvi, Mikael; Jokubavicius, Valdas; Sun, Jianwu

    Silicon carbide is emerging as a novel material for a range of energy and environmental technologies. Previously, silicon carbide was considered as a material mainly for transistor applications. We have initiated the use of silicon carbide material towards optoelectronics in general lighting and ...

  15. Radiation Damage in Silicon Detectors Caused by Hadronic and Electromagnetic Irradiation

    CERN Document Server

    Fretwurst, E.; Stahl, J.; Pintilie, I.

    2002-01-01

    The report contains various aspects of radiation damage in silicon detectors subjected to high intensity hadron and electromagnetic irradiation. It focuses on improvements for the foreseen LHC applications, employing oxygenation of silicon wafers during detector processing (result from CERN-RD48). An updated survey on hadron induced damage is given in the first article. Several improvements are outlined especially with respect to antiannealing problems associated with detector storage during LHC maintenance periods. Open questions are outlined in the final section, among which are a full understanding of differences found between proton and neutron induced damage, process related effects changing the radiation tolerance in addition to the oxygen content and the lack of understanding the changed detector properties on the basis of damage induced point and cluster defects. In addition to float zone silicon, so far entirely used for detector fabrication,Czochralski silicon was also studied and first promising re...

  16. Evaluation of a silicon oxynitride hydrophilic interaction liquid chromatography column in saccharide and glycoside separations.

    Science.gov (United States)

    Wan, Huihui; Sheng, Qianying; Zhong, Hongmin; Guo, Xiujie; Fu, Qing; Liu, Yanfang; Xue, Xingya; Liang, Xinmiao

    2015-05-01

    The retention characteristics of a silicon oxynitride stationary phase for carbohydrate separation were studied in hydrophilic interaction chromatography mode. Four saccharides including mono-, di-, and trisaccharides were employed to investigate the effects of water content and buffer concentration in the mobile phase on hydrophilic interaction liquid chromatography retention. For the tested saccharides, the silicon oxynitride column demonstrated excellent performance in terms of separation efficiency, hydrophilicity, and interesting separation selectivity for carbohydrates compared to the bare silica stationary phase. Finally, the silicon oxynitride hydrophilic interaction liquid chromatography column was employed in the separation of complex samples of fructooligosaccharides, saponins, and steviol glycoside from natural products. The resulting chromatograms demonstrated good separation efficiency and longer retention compared with silica, which further confirmed the advantages and potential application of silicon oxynitride stationary phase for hydrophilic interaction liquid chromatography separation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Determination of Shear Deformation Potentials from the Free-Carrier Piezobirefringence in Germanium and Silicon

    DEFF Research Database (Denmark)

    Riskaer, Sven

    1966-01-01

    The present investigations of the free-carrier piezobirefringence phenomenon verify that in n-type germanium and silicon as well as in p-type silicon this effect can be ascribed to intraband transitions of the carriers. It is demonstrated how a combined investigation of the low-stress and high......-stress piezobirefringence in these materials provides a direct and independent method for determining deformation-potential constants. For n-type germanium we obtain Ξu=18.0±0.5 eV, for n-type silicon Ξu=8.5±0.4 eV; for p-type silicon a rather crude analytical approximation yields b=-3.1 eV and d=-8.3 eV. Finally......, experimental evidence is given to support the assumption, that in p-type germanium intraband transitions alone cannot account for the free-carrier piezobirefringence....

  18. Design and test of a prototype silicon detector module for ATLAS Semiconductor Tracker endcaps

    CERN Document Server

    Clark, A G; Donega, M; Ferrère, D; Fortin, R; García, J E; González, S; Hirt, C; Ikegami, Y; Kagan, H; Kohriki, T; Kondo, T; Lindsay, S; MacPherson, A; Mangin-Brinet, M; Mikulec, B; Moorhead, G F; Niinikoski, T O; Pernegger, H; Perrin, E; Roe, S; Taylor, G N; Terada, S; Unno, Y; Vos, M; Wallny, R; Weber, M

    2005-01-01

    The ATLAS Semiconductor Tracker (SCT) will be a central part of the tracking system of the ATLAS experiment. The SCT consists of four concentric barrels of silicon detectors as well as two silicon endcap detectors formed by nine disks each. The layout of the forward silicon detector module presented in this paper is based on the approved layout of the silicon detectors of the SCT, their geometry and arrangement in disks, but uses otherwise components identical to the barrel modules of the SCT. The module layout is optimized for excellent thermal management and electrical performance, while keeping the assembly simple and adequate for a large scale module production. This paper summarizes the design and layout of the module and present results of a limited prototype production, which has been extensively tested in the laboratory and testbeam. The module design was not finally adopted for series production because a dedicated forward hybrid layout was pursued.

  19. 1366 Project Silicon: Reclaiming US Silicon PV Leadership

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Adam [1366 Technologies, Bedford, MA (United States)

    2016-02-16

    1366 Technologies’ Project Silicon addresses two of the major goals of the DOE’s PV Manufacturing Initiative Part 2 program: 1) How to reclaim a strong silicon PV manufacturing presence and; 2) How to lower the levelized cost of electricity (“LCOE”) for solar to $0.05-$0.07/kWh, enabling wide-scale U.S. market adoption. To achieve these two goals, US companies must commercialize disruptive, high-value technologies that are capable of rapid scaling, defensible from foreign competition, and suited for US manufacturing. These are the aims of 1366 Technologies Direct Wafer ™ process. The research conducted during Project Silicon led to the first industrial scaling of 1366’s Direct Wafer™ process – an innovative, US-friendly (efficient, low-labor content) manufacturing process that destroys the main cost barrier limiting silicon PV cost-reductions: the 35-year-old grand challenge of making quality wafers (40% of the cost of modules) without the cost and waste of sawing. The SunPath program made it possible for 1366 Technologies to build its demonstration factory, a key and critical step in the Company’s evolution. The demonstration factory allowed 1366 to build every step of the process flow at production size, eliminating potential risk and ensuring the success of the Company’s subsequent scaling for a 1 GW factory to be constructed in Western New York in 2016 and 2017. Moreover, the commercial viability of the Direct Wafer process and its resulting wafers were established as 1366 formed key strategic partnerships, gained entry into the $8B/year multi-Si wafer market, and installed modules featuring Direct Wafer products – the veritable proving grounds for the technology. The program also contributed to the development of three Generation 3 Direct Wafer furnaces. These furnaces are the platform for copying intelligently and preparing our supply chain – large-scale expansion will not require a bigger machine but more machines. SunPath filled the

  20. Elastically relaxed free-standing strained-silicon nanomembranes.

    Science.gov (United States)

    Roberts, Michelle M; Klein, Levente J; Savage, Donald E; Slinker, Keith A; Friesen, Mark; Celler, George; Eriksson, Mark A; Lagally, Max G

    2006-05-01

    Strain plays a critical role in the properties of materials. In silicon and silicon-germanium, strain provides a mechanism for control of both carrier mobility and band offsets. In materials integration, strain is typically tuned through the use of dislocations and elemental composition. We demonstrate a versatile method to control strain by fabricating membranes in which the final strain state is controlled by elastic strain sharing, that is, without the formation of defects. We grow Si/SiGe layers on a substrate from which they can be released, forming nanomembranes. X-ray-diffraction measurements confirm a final strain predicted by elasticity theory. The effectiveness of elastic strain to alter electronic properties is demonstrated by low-temperature longitudinal Hall-effect measurements on a strained-silicon quantum well before and after release. Elastic strain sharing and film transfer offer an intriguing path towards complex, multiple-layer structures in which each layer's properties are controlled elastically, without the introduction of undesirable defects.

  1. The silicon vertex detector of the Belle II experiment

    Science.gov (United States)

    Friedl, Markus; Bergauer, Thomas; Gfall, Immanuel; Irmler, Christian; Valentan, Manfred

    2011-02-01

    After 10 years of successful operation, the Belle experiment at KEK (Tsukuba, Japan) will be completed in 2010. Thereafter, a major upgrade of the KEK-B machine is foreseen until 2014, aiming at a final luminosity of 8×10 35 cm -2 s -1, which is about 40 times higher than the present peak value. Consequently, also the Belle experiment needs to be changed and the Silicon Vertex Detector (SVD) in particular will be completely replaced as it already operates close to its limits in the present system. The future SVD (a.k.a. SuperSVD) will consist of four layers of double-sided silicon strip detectors like the present one, but at larger radii, because it will be complemented by a two-layer pixel detector as the innermost sensing device. The SuperSVD will be entirely composed of silicon sensors made from 6 in. wafers read out by APV25 front-end chips that were originally developed for the CMS experiment at the LHC. Several years of R&D effort led to innovations such as the Origami chip-on-sensor concept and readout electronics with hit time finding which were successfully demonstrated on prototypes. These features will be included in the final system which is presently being designed. This paper will give an overview of the SuperSVD and present results from prototype tests ranging from detector modules to back-end electronics.

  2. III-V semiconductor devices integrated with silicon III-V semiconductor devices integrated with silicon

    Science.gov (United States)

    Hopkinson, Mark; Martin, Trevor; Smowton, Peter

    2013-09-01

    et al describe the transfer printing and bonding of III-V die on to CMOS wafers and Dastjerdi et al describe the optical performance of free-standing InGaAsP tube optical cavities which may be transferred to silicon substrates. Finally, describing important recent progress on GaN-based devices Jiang et al describe their work on InGaN light-emitting diodes on Si (1 1 1) substrates, Wallis et al describe similar structures with the emphasis on x-ray methods for the control of AlGaN buffer layer strain, Kumar et al describe low leakage current, large-area Schottky barrier photodetectors on Si, whilst Soltani et al describe their recent progress on AlGaN/GaN high electron mobility transistors grown on (1 0 0) and (1 1 0) silicon substrates. Overall, we think that this special issue of Semiconductor Science and Technology provides a timely overview of progress and the opportunities in this exciting and important field. Finally, we would like to thank the IOP editorial staff, in particular Alice Malhador, for their support, and we would also like to thank all contributors for their efforts in making this special issue possible.

  3. Silicon nanocrystals and defect states in silicon rich silicon nitride for optoelectronic applications

    Science.gov (United States)

    Mohammed, Shakil

    Research interest in silicon nanocrystals (Si-NC) has increased significantly as a result of the desire to improve the light emission efficiency of bulk silicon. Si-NCs embedded in silicon nitride have desirable characteristics for optoelectronic applications since they can increase the tunneling probability and have a lower tunneling barrier than silicon oxide. Higher tunneling probability is an important feature as it can be used to develop more efficient electroluminescent and photovoltaic devices. In this dissertation, the Si-rich Si3N 4 (SRN) was prepared using low pressure chemical vapor deposition (LPCVD) and RF sputtering followed by high temperature treatment in order to precipitate Si-NCs within the silicon nitride matrix. Several different characterization techniques were used on the Si-NC samples in order to understand the physical, structural, optical and electrical behavior of the nanocrystals. Characterization techniques used in this analysis included photoluminescence (PL), time resolved PL, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy, ellipsometry and capacitance-voltage (C-V) measurements. Silicon nitride was found to contain a high defect density which suppressed the PL effect from the Si-NC. The PL observed from each different SRN sample correlated to defect states, namely dangling bonds and oxygen related bonding. Although substantial evidence suggested that Si-NC had formed within the SRN sample, a PL effect due to the quantum confinement effect (QCE) from the nanocrystals could not be detected. However, Si rich SiOx samples exhibited excellent PL which correlated with the QCE for an indirect bandgap semiconductor. Further experiments were conducted using forming gas in order to passivate the defects in the SRN. Though significant changes in PL was not achieved due to passivation, the electrical behavior from the SRN indicated that the

  4. Silicon carbide fibers and articles including same

    Science.gov (United States)

    Garnier, John E; Griffith, George W

    2015-01-27

    Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500.degree. C. to approximately 2000.degree. C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01.times.10.sup.2 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.

  5. Methods for producing silicon carbide fibers

    Science.gov (United States)

    Garnier, John E.; Griffith, George W.

    2016-03-01

    Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500.degree. C. to approximately 2000.degree. C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01.times.10.sup.2 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.

  6. Solar silicon via the Dow Corning process

    Science.gov (United States)

    Hunt, L. P.; Dosaj, V. D.

    1979-01-01

    Technical feasibility for high volume production of solar cell-grade silicon is investigated. The process consists of producing silicon from pure raw materials via the carbothermic reduction of quartz. This silicon was then purified to solar grade by impurity segregation during Czochralski crystal growth. Commercially available raw materials were used to produce 100 kg quantities of silicon during 60 hour periods in a direct arc reactor. This silicon produced single crystalline ingot, during a second Czochralski pull, that was fabricated into solar cells having efficiencies ranging from 8.2 percent to greater than 14 percent. An energy analysis of the entire process indicated a 5 month payback time.

  7. Intraventricular Silicone Oil: A Case Report.

    Science.gov (United States)

    Mathis, Stéphane; Boissonnot, Michèle; Tasu, Jean-Pierre; Simonet, Charles; Ciron, Jonathan; Neau, Jean-Philippe

    2016-01-01

    Intracranial silicone oil is a rare complication of intraocular endotamponade with silicone oil. We describe a case of intraventricular silicone oil fortuitously observed 38 months after an intraocular tamponade for a complicated retinal detachment in an 82 year-old woman admitted in the Department of Neurology for a stroke. We confirm the migration of silicone oil along the optic nerve. We discuss this rare entity with a review of the few other cases reported in the medical literature. Intraventricular migration of silicone oil after intraocular endotamponade is usually asymptomatic but have to be known of the neurologists and the radiologists because of its differential diagnosis that are intraventricular hemorrhage and tumor.

  8. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Black, Marcie [Bandgap Engineering, Lincoln, MA (United States)

    2014-10-30

    This project aimed to demonstrate increased electronic coupling in silicon nanostructures relative to bulk silicon for the purpose of making high efficiency intermediate bandgap solar cells using silicon. To this end, we formed nanowires with controlled crystallographic orientation, small diameter, <111> sidewall faceting, and passivated surfaces to modify the electronic band structure in silicon by breaking down the symmetry of the crystal lattice. We grew and tested these silicon nanowires with <110>-growth axes, which is an orientation that should produce the coupling enhancement.

  9. Silicon on insulator self-aligned transistors

    Science.gov (United States)

    McCarthy, Anthony M.

    2003-11-18

    A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

  10. Method For Producing Mechanically Flexible Silicon Substrate

    KAUST Repository

    Hussain, Muhammad Mustafa

    2014-08-28

    A method for making a mechanically flexible silicon substrate is disclosed. In one embodiment, the method includes providing a silicon substrate. The method further includes forming a first etch stop layer in the silicon substrate and forming a second etch stop layer in the silicon substrate. The method also includes forming one or more trenches over the first etch stop layer and the second etch stop layer. The method further includes removing the silicon substrate between the first etch stop layer and the second etch stop layer.

  11. Hybrid Integrated Platforms for Silicon Photonics

    Directory of Open Access Journals (Sweden)

    John E. Bowers

    2010-03-01

    Full Text Available A review of recent progress in hybrid integrated platforms for silicon photonics is presented. Integration of III-V semiconductors onto silicon-on-insulator substrates based on two different bonding techniques is compared, one comprising only inorganic materials, the other technique using an organic bonding agent. Issues such as bonding process and mechanism, bonding strength, uniformity, wafer surface requirement, and stress distribution are studied in detail. The application in silicon photonics to realize high-performance active and passive photonic devices on low-cost silicon wafers is discussed. Hybrid integration is believed to be a promising technology in a variety of applications of silicon photonics.

  12. Aleph silicon microstrip vertex detector

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This microstrip vertex locator was located at the heart of the ALEPH experiment, one of the four experiments at the Large Electron-Positron (LEP) collider. In the experiments at CERN's LEP, which ran from 1989 to 2000, modern silicon microvertex detectors, such as those used at ALEPH, monitored the production of short-lived particles close to the beam pipe.

  13. Magnetically retained silicone facial prosthesis

    African Journals Online (AJOL)

    straps, spectacle frames, extension from the denture, magnets, adhesives and implants material.[4] In this case report using maxillofacial silicone material and magnets, the prosthesis was constructed to camouflage the facial defect more esthetically. Case Report. A 67‑year‑old male patient was referred to the department.

  14. Magnetically retained silicone facial prosthesis

    African Journals Online (AJOL)

    Key words: Magnet retention, oro cutaneous fistula, silicone maxillofacial prosthesis. Date of Acceptance: 09-Jun-2013. Address for correspondence: Dr. Suresh Venugopalan, Department of Prosthodontics,. Saveetha Dental College, Ponamalle High Road,. Chennai ‑ 600 077, Tamil Nadu, India. E‑mail: ...

  15. Behavior of dislocations in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Sumino, Koji [Nippon Steel Corp., Chiba Prefecture (Japan)

    1995-08-01

    A review is given of dynamic behavior of dislocations in silicon on the basis of works of the author`s group. Topics taken up are generation, motion and multiplication of dislocations as affected by oxygen impurities and immobilization of dislocations due to impurity reaction.

  16. Seedless electroplating on patterned silicon

    NARCIS (Netherlands)

    Vargas Llona, Laura Dolores; Jansen, Henricus V.; Elwenspoek, Michael Curt

    2006-01-01

    Nickel thin films have been electrodeposited without the use of an additional seed layer, on highly doped silicon wafers. These substrates conduct sufficiently well to allow deposition using a peripherical electrical contact on the wafer. Films 2 μm thick have been deposited using a nickel sulfamate

  17. Silicon nitride microwave photonic circuits

    NARCIS (Netherlands)

    Roeloffzen, C.G.H.; Zhuang, L.; Taddei, Caterina; Taddei, Caterina; Leinse, Arne; Heideman, Rene; van Dijk, Paulus W.L.; Oldenbeuving, Ruud; Marpaung, D.A.I.; Burla, M.; Buria, Maurizio; Boller, Klaus J.

    2013-01-01

    We present an overview of several microwave photonic processing functionalities based on combinations of Mach-Zehnder and ring resonator filters using the high index contrast silicon nitride (TriPleXTM) waveguide technology. All functionalities are built using the same basic building blocks, namely

  18. Theory of unsaturated silicon lattices

    Science.gov (United States)

    Zhang, Feng; Stucke, David; Stojkovic, Dragan; Crespi, Vincent

    2008-03-01

    Several molecules are known to contain stable silicon double or triple bonds that are sterically protected by bulky side groups. Through first-principles computation, we demonstrate that well-defined π bonds can also be formed in two prototypical crystalline Si structures: Schwarzite Si-168 and dilated diamond. The sp^2-bonded Si-168 is thermodynamically preferred over diamond silicon at a modest negative pressure of -2.5 GPa. Ab-initio molecular dynamics simulations of Si-168 at 1000 K reveal significant thermal stability. Si-168 is metallic in density functional theory, but with distinct π-like and &*circ;-like valence and conduction band complexes just above and below the Fermi energy. A bandgap buried in the valence band but close to the Fermi level can be accessed via hole doping in semiconducting Si144B24. A less-stable crystalline system with a silicon-silicon triple bond is also examined: a rare-gas intercalated open framework on a dilated diamond lattice.

  19. Mesoporous Silicon-Based Anodes

    Science.gov (United States)

    Peramunage, Dharmasena

    2015-01-01

    For high-capacity, high-performance lithium-ion batteries. A new high-capacity anode composite based on mesoporous silicon is being developed. With a structure that resembles a pseudo one-dimensional phase, the active anode material will accommodate significant volume changes expected upon alloying and dealloying with lithium (Li).

  20. Let’s talk silicon

    Science.gov (United States)

    While silicon (Si) has been a known plant nutrient for centuries, how plants use this element is still poorly understood. Researchers have identified how plants acquire Si from the environment and transport the element to all plant tissues, including roots, stems, petioles, leaves and flowers. We ...

  1. Pathology of silicon carbide pneumoconiosis.

    Science.gov (United States)

    Massé, S; Bégin, R; Cantin, A

    1988-03-01

    Silicon carbide is a widely used synthetic abrasive manufactured by heating silica and coke in electric furnaces at 2400 degrees C. Until recently it had been considered a relatively inert dust in humans and animals. However, several roentgenologic surveys had revealed lesions similar to low-grade silicosis. A recent epidemiological study has revealed a 35% incidence of pulmonary problems. Tissues from three such workers were available for light microscopy. A mixed pneumoconiosis was found, and lesions can be summarized as follows: (a) abundance of intraalveolar macrophages associated with a mixture of inhaled particles including carbon, silicon, pleomorphic crystals, silicon carbide, and ferruginous bodies showing a thin black central core; (b) nodular fibrosis, generally profuse, containing silica and ferruginous bodies and associated with large amount of carbon pigment; (c) interstitial fibrosis, less prominent than the nodular form; (d) carcinoma in two cases. We believe this pneumoconiosis is sufficiently characteristic to be recognized as a distinct entity. The Stanton hypothesis on fiber properties and carcinogenesis could be applied to silicon carbide dust. At present, it appears that the occupational hazard is limited to the manufacturing process and powdered product used in some industries.

  2. Microelectromechanical pump utilizing porous silicon

    Science.gov (United States)

    Lantz, Jeffrey W [Albuquerque, NM; Stalford, Harold L [Norman, OK

    2011-07-19

    A microelectromechanical (MEM) pump is disclosed which includes a porous silicon region sandwiched between an inlet chamber and an outlet chamber. The porous silicon region is formed in a silicon substrate and contains a number of pores extending between the inlet and outlet chambers, with each pore having a cross-section dimension about equal to or smaller than a mean free path of a gas being pumped. A thermal gradient is provided along the length of each pore by a heat source which can be an electrical resistance heater or an integrated circuit (IC). A channel can be formed through the silicon substrate so that inlet and outlet ports can be formed on the same side of the substrate, or so that multiple MEM pumps can be connected in series to form a multi-stage MEM pump. The MEM pump has applications for use in gas-phase MEM chemical analysis systems, and can also be used for passive cooling of ICs.

  3. Untreated silicone breast implant rupture.

    Science.gov (United States)

    Hölmich, Lisbet R; Vejborg, Ilse M; Conrad, Carsten; Sletting, Susanne; Høier-Madsen, Mimi; Fryzek, Jon P; McLaughlin, Joseph K; Kjøller, Kim; Wiik, Allan; Friis, Søren

    2004-07-01

    Implant rupture is a well-known complication of breast implant surgery that can pass unnoticed by both patient and physician. To date, no prospective study has addressed the possible health implications of silicone breast implant rupture. The aim of the present study was to evaluate whether untreated ruptures are associated with changes over time in magnetic resonance imaging findings, serologic markers, or self-reported breast symptoms. A baseline magnetic resonance imaging examination was performed in 1999 on 271 women who were randomly chosen from a larger cohort of women having cosmetic breast implants for a median period of 12 years (range, 3 to 25 years). A follow-up magnetic resonance imaging examination was carried out in 2001, excluding women who underwent explantation in the period between the two magnetic resonance imaging examinations (n = 44). On the basis of these examinations, the authors identified 64 women who had at least one ruptured implant at the first magnetic resonance imaging examination and, for comparison, all women who had intact implants at both examinations (n = 98). Magnetic resonance images from the two examinations were compared and changes in rupture configuration were evaluated. Comparisons were also made for self-reported breast symptoms occurring during the study period and for changes in serum values of antinuclear antibodies, rheumatoid factor, and cardiolipin antibodies immunoglobulin G and immunoglobulin M. The majority of the women with implant rupture had no visible magnetic resonance imaging changes of their ruptured implants. For 11 implants (11 percent) in 10 women, the authors observed progression of silicone seepage, either as a conversion from intracapsular into extracapsular rupture (n = 7), as progression of extra-capsular silicone (n = 3), or as increasing herniation of the silicone within the fibrous capsule (n = 1); however, in most cases, these changes were minor. Some changes could be ascribed to trauma, but

  4. Flexible Thermoelectric Generators on Silicon Fabric

    KAUST Repository

    Sevilla, Galo T.

    2012-11-01

    In this work, the development of a Thermoelectric Generator on Flexible Silicon Fabric is explored to extend silicon electronics for flexible platforms. Low cost, easily deployable plastic based flexible electronics are of great interest for smart textile, wearable electronics and many other exciting applications. However, low thermal budget processing and fundamentally limited electron mobility hinders its potential to be competitive with well established and highly developed silicon technology. The use of silicon in flexible electronics involve expensive and abrasive materials and processes. In this work, high performance flexible thermoelectric energy harvesters are demonstrated from low cost bulk silicon (100) wafers. The fabrication of the micro- harvesters was done using existing silicon processes on silicon (100) and then peeled them off from the original substrate leaving it for reuse. Peeled off silicon has 3.6% thickness of bulk silicon reducing the thermal loss significantly and generating nearly 30% more output power than unpeeled harvesters. The demonstrated generic batch processing shows a pragmatic way of peeling off a whole silicon circuitry after conventional fabrication on bulk silicon wafers for extremely deformable high performance integrated electronics. In summary, by using a novel, low cost process, this work has successfully integrated existing and highly developed fabrication techniques to introduce a flexible energy harvester for sustainable applications.

  5. Radiation damage in silicon. Defect analysis and detector properties

    Energy Technology Data Exchange (ETDEWEB)

    Hoenniger, F.

    2008-01-15

    Silicon microstrip and pixel detectors are vital sensor-components as particle tracking detectors for present as well as future high-energy physics (HEP) experiments. All experiments at the large Hadron Collider (LHC) are equipped with such detectors. Also for experiments after the upgrade of the LHC (the so-called Super-LHC), with its ten times higher luminosity, or the planned International Linear Collider (ILC) silicon tracking detectors are forseen. Close to the interaction region these detectors have to face harsh radiation fields with intensities above the presently tolerable level. defect engineering of the used material, e. g. oxygen enrichment of high resistivity float zone silicon and growing of thin low resistivityepitaxial layers on Czochralski silicon substrates has been established to improve the radiation hardness of silicon sensors. This thesis focuses mainly on the investigation of radiation induced defects and their differences observed in various kinds of epitaxial silicon material. Comparisons with other materials like float zone or Czochralski silicon are added. Deep Level Transient Spectroscopy (DLTS) and Thermally Stimulated Current (TSC) measurements have been performed after {gamma}-, electron-, proton- and neutron-irradiation. The differenced in the formation of vacancy and interstitial related defects as well as so-called clustered regions were investigated for various types of irradiation. In addition to the well known defects VO{sub i}, C{sub i}O{sub i}, C{sub i}C{sub s}, VP or V{sub 2} several other defect complexes have been found and investigated. Also the material dependence of the defect introduction rates and the defect annealing behavior has been studied by isothermal and isochronal annealing experiments. Especially the IO{sub 2} defect which is an indicator for the oxygen-dimer content of the material has been investigated in detail. On the basis of radiation induced defects like the bistable donor (BD) defect and a deep

  6. Aluminum gettering in single and multicrystalline silicon

    Energy Technology Data Exchange (ETDEWEB)

    McHugo, S.A.; Hieslmair, H.; Weber, E.R. [Univ. of California, Berkeley, CA (United States)

    1995-08-01

    Al gettering has been performed on integrated circuit (I.C.) quality silicon and a variety of single and multicrystalline silicon solar cell materials. The minority carrier diffusion length, Ln, has been used to quantify the gettering response. Vast differences in response to the Al gettering treatment are observed between the I.C. quality silicon and the solar cell materials. The I.C. silicon generally responds well while the solar cell silicon performance progressively degrades with increasing gettering temperature. Preliminary data shows that by performing a Rapid Thermal Annealing treatment prior to the Al gettering, an improved or further degraded Ln emerges in solar cell material depending on the material`s manufacturer. We explain these observed phenomena by suggesting that Al gettering in solar cell silicon is an impurity emission-limited process while for I.C. quality silicon it is diffusion limited.

  7. Structural and optical properties of porous silicon prepared by anodic etching of irradiated silicon

    Science.gov (United States)

    Vendamani, V. S.; Nageswara Rao, S. V. S.; Pathak, A. P.

    2013-11-01

    Porous silicon (pSi) is considered to be a potential material in the field of electronics and optoelectronics because of its strong luminescence in visible and near-infrared region. Swift Heavy Ion (SHI) beam irradiation shows versatile effects on physical and optical properties of porous silicon. The p-type (1 0 0) Si was irradiated with 80 MeV Ni ions at various fluences ranging from 1 × 1011 to 5 × 1013 ions/cm2. The irradiated samples were anodically etched to get porous Si. Field Emission Scanning Electron Microscope (FESEM) images confirm the presence of uniform sponge like surface in pSi layers. The photoluminescence (PL) peak position is found to shift towards the higher wavelength (red shift) by increase in fluence. The increased defect states are expected to be responsible for the observed exponential degradation in PL intensity. The pSi layer thickness is found to decrease with increase in fluence. The refractive index (n) measurements on pSi were consistent with structural and optical measurements. Finally we found that Ni ion irradiation promotes aging effects leading to some observable blue shift in PL.

  8. Silicon carbonitride nanolayers - Synthesis and chemical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, P.S., E-mail: dg7j@ca.tu-darmstadt.de [Technische Universitaet Darmstadt, Materials Science, Petersenstr. 23, 64287 Darmstadt (Germany); Fainer, N.I. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Acad. Lavrentjev Pr. 3, Novosibirsk 630090 (Russian Federation); Baake, O. [Technische Universitaet Darmstadt, Materials Science, Petersenstr. 23, 64287 Darmstadt (Germany); Kosinova, M.L.; Rumyantsev, Y.M.; Trunova, V.A. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Acad. Lavrentjev Pr. 3, Novosibirsk 630090 (Russian Federation); Klein, A. [Technische Universitaet Darmstadt, Materials Science, Petersenstr. 23, 64287 Darmstadt (Germany); Pollakowski, B.; Beckhoff, B. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Ensinger, W. [Technische Universitaet Darmstadt, Materials Science, Petersenstr. 23, 64287 Darmstadt (Germany)

    2012-07-01

    SiC{sub x}N{sub y} thin films were produced by plasma-enhanced chemical vapor deposition and characterized by ellipsometry, Fourier transform infrared and Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, as well as, by near-edge X-ray absorption fine structure measurements in total-reflection X-ray fluorescence geometry. The temperature of synthesis was varied between 100 Degree-Sign C and 800 Degree-Sign C, the precursors hexamethyldisilazane or hexamethylcyclotrisilazane were used with an addition of N{sub 2}, He, and NH{sub 3}, respectively. The composition of the products was determined to be constant in Si with about 20 at.%, whereas the sum of C and N results in 80 at.% (each varying between 20 and 60 at.%). Consequently, it can be stated, that in the produced silicon carbonitride a network of Si is built with Si-C-Si, Si-C-C-Si, and Si-N-Si bridges. The comparison of the chemical composition and of the physical properties shows for the samples produced with He or N{sub 2}, respectively (without NH{sub 3}) that the refractive index and the absorption coefficient are increasing with an increasing content of carbon in the final formula SiC{sub 4-n}N{sub n} (with n = 1, 2, or 3). - Highlights: Black-Right-Pointing-Pointer Silicon carbonitride nanolayers were produced by chemical vapor deposition. Black-Right-Pointing-Pointer The chemical bonds Si-C, Si-N, and C-C were identified. Black-Right-Pointing-Pointer The tetragonal structure contains cross-linking Si-C-Si, Si-N-Si, and Si-C-C-Si. Black-Right-Pointing-Pointer The elemental composition can be given as SiC{sub 4-n}N{sub n} (n = 1, 2, 3)

  9. Silicon-Based Anode and Method for Manufacturing the Same

    Science.gov (United States)

    Yushin, Gleb Nikolayevich (Inventor); Luzinov, Igor (Inventor); Zdyrko, Bogdan (Inventor); Magasinski, Alexandre (Inventor)

    2017-01-01

    A silicon-based anode comprising silicon, a carbon coating that coats the surface of the silicon, a polyvinyl acid that binds to at least a portion of the silicon, and vinylene carbonate that seals the interface between the silicon and the polyvinyl acid. Because of its properties, polyvinyl acid binders offer improved anode stability, tunable properties, and many other attractive attributes for silicon-based anodes, which enable the anode to withstand silicon cycles of expansion and contraction during charging and discharging.

  10. National solar technology roadmap: Film-silicon PV

    Energy Technology Data Exchange (ETDEWEB)

    Keyes, Brian [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2007-06-01

    Silicon photovoltaic (PV) technologies are addressed in two different technology roadmaps: Film-Silicon PV and Wafer-Silicon PV. This Film-Silicon PV roadmap applies to all silicon-film technologies that rely on a supporting substrate such as glass, polymer, aluminum, stainless steel, or metallurgical-grade silicon. Such devices typically use amorphous, nanocrystalline, fine-grained polycrystalline, or epitaxial silicon layers that are 1–20 μm thick.

  11. [A micro-silicon multi-slit spectrophotometer based on MEMS technology].

    Science.gov (United States)

    Hao, Peng; Wu, Yi-Hui; Zhang, Ping; Liu, Yong-Shun; Zhang, Ke; Li, Hai-Wen

    2009-06-01

    A new mini-spectrophotometer was developed by adopting micro-silicon slit and pixel segmentation technology, and this spectrophotometer used photoelectron diode array as the detector by the back-dividing-light way. At first, the effect of the spectral bandwidth on the tested absorbance linear correlation was analyzed. A theory for the design of spectrophotometer's slit was brought forward after discussing the relationships between spectrophotometer spectrum band width and pre-and post-slits width. Then, the integrative micro-silicon-slit, which features small volume, high precision, and thin thickness, was manufactured based on the MEMS technology. Finally, a test was carried on linear absorbance solution by this spectrophotometer. The final result showed that the correlation coefficients were larger than 0.999, which means that the new mini-spectrophotometer with micro-silicon slit pixel segmentation has an obvious linear correlation.

  12. Silica-sol-based spin-coating barrier layer against phosphorous diffusion for crystalline silicon solar cells

    Science.gov (United States)

    Uzum, Abdullah; Fukatsu, Ken; Kanda, Hiroyuki; Kimura, Yutaka; Tanimoto, Kenji; Yoshinaga, Seiya; Jiang, Yunjian; Ishikawa, Yasuaki; Uraoka, Yukiharu; Ito, Seigo

    2014-12-01

    The phosphorus barrier layers at the doping procedure of silicon wafers were fabricated using a spin-coating method with a mixture of silica-sol and tetramethylammonium hydroxide, which can be formed at the rear surface prior to the front phosphorus spin-on-demand (SOD) diffusion and directly annealed simultaneously with the front phosphorus layer. The optimization of coating thickness was obtained by changing the applied spin-coating speed; from 2,000 to 8,000 rpm. The CZ-Si p-type silicon solar cells were fabricated with/without using the rear silica-sol layer after taking the sheet resistance measurements, SIMS analysis, and SEM measurements of the silica-sol material evaluations into consideration. For the fabrication of solar cells, a spin-coating phosphorus source was used to form the n+ emitter and was then diffused at 930°C for 35 min. The out-gas diffusion of phosphorus could be completely prevented by spin-coated silica-sol film placed on the rear side of the wafers coated prior to the diffusion process. A roughly 2% improvement in the conversion efficiency was observed when silica-sol was utilized during the phosphorus diffusion step. These results can suggest that the silica-sol material can be an attractive candidate for low-cost and easily applicable spin-coating barrier for any masking purpose involving phosphorus diffusion.

  13. Silica-sol-based spin-coating barrier layer against phosphorous diffusion for crystalline silicon solar cells.

    Science.gov (United States)

    Uzum, Abdullah; Fukatsu, Ken; Kanda, Hiroyuki; Kimura, Yutaka; Tanimoto, Kenji; Yoshinaga, Seiya; Jiang, Yunjian; Ishikawa, Yasuaki; Uraoka, Yukiharu; Ito, Seigo

    2014-01-01

    The phosphorus barrier layers at the doping procedure of silicon wafers were fabricated using a spin-coating method with a mixture of silica-sol and tetramethylammonium hydroxide, which can be formed at the rear surface prior to the front phosphorus spin-on-demand (SOD) diffusion and directly annealed simultaneously with the front phosphorus layer. The optimization of coating thickness was obtained by changing the applied spin-coating speed; from 2,000 to 8,000 rpm. The CZ-Si p-type silicon solar cells were fabricated with/without using the rear silica-sol layer after taking the sheet resistance measurements, SIMS analysis, and SEM measurements of the silica-sol material evaluations into consideration. For the fabrication of solar cells, a spin-coating phosphorus source was used to form the n(+) emitter and was then diffused at 930°C for 35 min. The out-gas diffusion of phosphorus could be completely prevented by spin-coated silica-sol film placed on the rear side of the wafers coated prior to the diffusion process. A roughly 2% improvement in the conversion efficiency was observed when silica-sol was utilized during the phosphorus diffusion step. These results can suggest that the silica-sol material can be an attractive candidate for low-cost and easily applicable spin-coating barrier for any masking purpose involving phosphorus diffusion.

  14. Colloidal Photoluminescent Amorphous Porous Silicon, Methods Of Making Colloidal Photoluminescent Amorphous Porous Silicon, And Methods Of Using Colloidal Photoluminescent Amorphous Porous Silicon

    KAUST Repository

    Chaieb, Sahraoui

    2015-04-09

    Embodiments of the present disclosure provide for a colloidal photoluminescent amorphous porous silicon particle suspension, methods of making a colloidal photoluminescent amorphous porous silicon particle suspension, methods of using a colloidal photoluminescent amorphous porous silicon particle suspension, and the like.

  15. Debug automation from pre-silicon to post-silicon

    CERN Document Server

    Dehbashi, Mehdi

    2015-01-01

    This book describes automated debugging approaches for the bugs and the faults which appear in different abstraction levels of a hardware system. The authors employ a transaction-based debug approach to systems at the transaction-level, asserting the correct relation of transactions. The automated debug approach for design bugs finds the potential fault candidates at RTL and gate-level of a circuit. Debug techniques for logic bugs and synchronization bugs are demonstrated, enabling readers to localize the most difficult bugs. Debug automation for electrical faults (delay faults)finds the potentially failing speedpaths in a circuit at gate-level. The various debug approaches described achieve high diagnosis accuracy and reduce the debugging time, shortening the IC development cycle and increasing the productivity of designers. Describes a unified framework for debug automation used at both pre-silicon and post-silicon stages; Provides approaches for debug automation of a hardware system at different levels of ...

  16. Reactive magnetron sputtering of silicon to produce silicon oxide

    Science.gov (United States)

    Howson, R. P.; Danson, N.; Hall, G. W.

    1997-01-01

    Well controlled silicon dioxide films with refractive index 1.400-1.490 have been deposited at rates of up to 0.85 nm/s from a 100 mm diameter polycrystalline silicon cathode, sputtered at 200 W of 40 kHz rectified AC power in a reactive environment. This frequency used with control of the partial pressure of the oxygen in the system from the cathode potential has demonstrated an ability to reactively sputter silicon oxide of high quality. Stress/stoichiometry curves showed a peak in stress at a refractive index of 1.460 indicating both a dense structure and optimised SiO 2. We have demonstrated a pulsing system for the admission of oxygen into the silicon sputtering system which is under the control of a signal derived from the voltage appearing on the cathode when sputtering at constant power. Such a signal indicates the sputtering status of the target as to the degree to which the cathode is covered with oxide i.e. poisoned. By varying combinations of reactive gas flow rate and switching levels, different film compositions could be reproducibly and reliably obtained. The growing films could be subjected to a externally-varied degree of argon-ion bombardment with a simple modification of the geometry of the unbalanced magnetron used for the sputtering. The amount of ion bombardment with such a system was also a function of the argon sputtering pressure that was used. Increased argon-ion bombardment resulted in more compressive stress in the film that was produced.

  17. Arsenate reduction and methylation in the cells of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 investigated with X-ray absorption near edge structure

    Energy Technology Data Exchange (ETDEWEB)

    Su, S.M., E-mail: shimingsu@163.com [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing (China); Zeng, X.B., E-mail: zengxb@ieda.org.cn [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing (China); Li, L.F.; Duan, R.; Bai, L.Y. [Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Environment, Ministry of Agriculture, Beijing (China); Li, A.G.; Wang, J.; Jiang, S. [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Three fungal strains are capable of As(V) reduction and methylation. Black-Right-Pointing-Pointer As(V) reduction might be more easily processed than the methylation in fungal cells. Black-Right-Pointing-Pointer As sequestration and speciation transformation might be the detoxification processes. - Abstract: Synchrotron radiation-based X-ray absorption near edge structure (XANES) was introduced to directly analysis chemical species of arsenic (As) in the cells of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 capable of As accumulation and volatilisation. After exposure to As(V) of 500 mg L{sup -1} for 15 days, a total of 60.5% and 65.3% of the accumulated As in the cells of T. asperellum SM-12F1 and P. janthinellum SM-12F4, respectively, was As(III), followed by 31.3% and 32.4% DMA (dimethylarsinic acid), 8.3% and 2.3% MMA (monomethylarsonic acid), respectively. However, for F. oxysporum CZ-8F1, 54.5% of the accumulated As was As(III), followed by 37.8% MMA and 7.7% As(V). The reduction and methylation of As(V) formed As(III), MMA, and DMA as the primacy products, and the reduction of As(V) might be more easily processed than the methylation. These results will help to understanding the mechanisms of As detoxification and its future application in bioremediation.

  18. Model My Watershed and BiG CZ Data Portal: Interactive geospatial analysis and hydrological modeling web applications that leverage the Amazon cloud for scientists, resource managers and students

    Science.gov (United States)

    Aufdenkampe, A. K.; Mayorga, E.; Tarboton, D. G.; Sazib, N. S.; Horsburgh, J. S.; Cheetham, R.

    2016-12-01

    The Model My Watershed Web app (http://wikiwatershed.org/model/) was designed to enable citizens, conservation practitioners, municipal decision-makers, educators, and students to interactively select any area of interest anywhere in the continental USA to: (1) analyze real land use and soil data for that area; (2) model stormwater runoff and water-quality outcomes; and (3) compare how different conservation or development scenarios could modify runoff and water quality. The BiG CZ Data Portal is a web application for scientists for intuitive, high-performance map-based discovery, visualization, access and publication of diverse earth and environmental science data via a map-based interface that simultaneously performs geospatial analysis of selected GIS and satellite raster data for a selected area of interest. The two web applications share a common codebase (https://github.com/WikiWatershed and https://github.com/big-cz), high performance geospatial analysis engine (http://geotrellis.io/ and https://github.com/geotrellis) and deployment on the Amazon Web Services (AWS) cloud cyberinfrastructure. Users can use "on-the-fly" rapid watershed delineation over the national elevation model to select their watershed or catchment of interest. The two web applications also share the goal of enabling the scientists, resource managers and students alike to share data, analyses and model results. We will present these functioning web applications and their potential to substantially lower the bar for studying and understanding our water resources. We will also present work in progress, including a prototype system for enabling citizen-scientists to register open-source sensor stations (http://envirodiy.org/mayfly/) to stream data into these systems, so that they can be reshared using Water One Flow web services.

  19. A general classification of silicon utilizing organisms

    Science.gov (United States)

    Das, P.; Das, S.

    2010-12-01

    Silicon utilizing organisms may be defined as organisms with high silicon content (≥ 1% dry weight) and they can metabolize silicon with or without demonstrable silicon transporter genes (SIT) in them(Das,2010). Silicon is the second most abundant element in the lithosphere (27.70%) and it is as important as phosphorus and magnesium (0.03%) in the biota. Hydrated silica represents the second most abundant biogenic mineral after carbonate minerals. Silicon is accumulated and metabolized by some prokaryotes, and Si compounds can stimulate the growth of a range of fungi. It is well known that Si is essential for diatoms. In mammals, Si is considered an essential trace element, required in bone, cartilage and connective tissue formation, enzymatic activities and other metabolic processes. Silicon was suggested to act as a phosphoprotein effector in bone. In mammals, Si is also reported to positively influence the immune system and to be required for lymphocyte proliferation. The aqueous chemistry of Si is dominated by silicic acid at biological pH ranges. Monosilicic acid can form stable complexes with organic hydroxy-containing molecules . Biosilica also has been identified associated with various biomolecules including proteins and carbohydrates. There are main seven groups of silicon utilizing organisms belonging to Gram positive bacteria, algae, protozoa, sponges, fungi, lichens, and monocotyledon plants. In each group again all the members are not silicon utilizing organisms, thus selective members in each group are further classified depending their degree of silicon utilization. Important silicon utilizing bacteria are Mycobacteria, Nocardia, Streptomyces, Staphylococcus, Bacillus, Lactobacillus spp. etc., Important silicon utilizing algae are Centrobacillariophyceae, Pennatibacillariophyceae and Chrysophyceae. Many protozoa belonging to Heterokonta, Choanoflagellida, Actinopoda are well known silicon utilizing microorganisms. Hexactinellida ( glass sponges

  20. Silicon photonics: Design, fabrication, and characterization of on-chip optical interconnects

    Science.gov (United States)

    Hsieh, I.-Wei

    devices are quite different from those of electronic devices. Minimizing propagation losses by reducing sidewall roughness to nanometer scale over a device length of several millimeters or even centimeters has prompted researchers in academia and industry to refine the fabrication process. Chapter 3 of this thesis summarizes our efforts in fabricating silicon photonic devices using standard CMOS technology. Chapter 4 describes the characterization of nonlinear effects, including self-phase modulation (SPM), cross-phase modulation (XPM), and supercontinuum generation in silicon-wire waveguides. Silicon-wire waveguides are strip waveguides with submicron transverse dimensions, which allow strong light confinement inside the silicon core. This strong optical confinement, in addition to the large third-order nonlinear optical susceptibility of crystalline silicon, leads to a net nonlinearity which is several orders of magnitude higher than the nonlinearity of silica fiber. Significant nonlinear effects can be observed and characterized over a device length of only several millimeters in silicon wires with very small input power. These effects provide opportunities for engineers to design active silicon photonic devices which are compact and energy-efficient. Chapter 5 presents a realization of an integrated SOI optical isolator, which is a critical yet often overlooked component in photonic integrated circuits. This study shows the feasibility to make a hybrid garnet/SOI active device with very promising results. Finally, Chapter 6 summarizes our demonstration of transmitting terabit-scale data streams in silicon-wire waveguides, which is an important first-step towards enabling intra-chip interconnection networks with ultra-high bandwidths. Although the scope of this thesis is limited to providing only fractional views of the whole silicon photonics area, it provides enough references for interested readers to conduct further literature research in other aspects of silicon

  1. Choosing a Silicone Encapsulant for Photovoltaic Applications

    Science.gov (United States)

    Velderrain, Michelle

    2011-12-01

    Growth in the solar industry has resulted in newer technologies, specifically concentrator photovoltaic (CPV) modules, to explore using new types of materials such as silicone encapsulants. CPV and LCPV module designs are to achieve the most efficient energy conversion possible however it is equally important to demonstrate long term reliability. Silicone is a material of interest due to its thermal stability and ability to absorb stresses incurred during thermal cycling. The refractive index of clear silicone adhesives is advantageous because it can be optimized using phenyl groups to match BK7 glass and other substrates to minimize light loss at the interfaces but it is relatively unknown how the optical properties change over time possibly yellowing in such a harsh environment. A 1.41 silicone encapsulant is compared to a 1.52 refractive index silicone. Optical Absorption (300 nm-1300 nm), Water Vapor Permeability, Moisture Absorption and effects of oxidation at elevated temperatures will be compared of these materials to aid the engineer in choosing a silicone for their CPV application. Non-phenyl containing 1.41 RI silicones have been used for several years for bonding solar arrays in the satellite industry. Phenyl groups on the siloxane polymer can change various properties of the silicone. Understanding how phenyl affects these properties allows the engineer to understand the benefits and risks when using a RI matching silicone to minimize light loss versus a non-phenyl containing silicone.

  2. Creep analysis of silicone for podiatry applications.

    Science.gov (United States)

    Janeiro-Arocas, Julia; Tarrío-Saavedra, Javier; López-Beceiro, Jorge; Naya, Salvador; López-Canosa, Adrián; Heredia-García, Nicolás; Artiaga, Ramón

    2016-10-01

    This work shows an effective methodology to characterize the creep-recovery behavior of silicones before their application in podiatry. The aim is to characterize, model and compare the creep-recovery properties of different types of silicone used in podiatry orthotics. Creep-recovery phenomena of silicones used in podiatry orthotics is characterized by dynamic mechanical analysis (DMA). Silicones provided by Herbitas are compared by observing their viscoelastic properties by Functional Data Analysis (FDA) and nonlinear regression. The relationship between strain and time is modeled by fixed and mixed effects nonlinear regression to compare easily and intuitively podiatry silicones. Functional ANOVA and Kohlrausch-Willians-Watts (KWW) model with fixed and mixed effects allows us to compare different silicones observing the values of fitting parameters and their physical meaning. The differences between silicones are related to the variations of breadth of creep-recovery time distribution and instantaneous deformation-permanent strain. Nevertheless, the mean creep-relaxation time is the same for all the studied silicones. Silicones used in palliative orthoses have higher instantaneous deformation-permanent strain and narrower creep-recovery distribution. The proposed methodology based on DMA, FDA and nonlinear regression is an useful tool to characterize and choose the proper silicone for each podiatry application according to their viscoelastic properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. New developments of the R&D silicon tracking for linear collider on ...

    Indian Academy of Sciences (India)

    end and readout chips in deep sub-micron CMOS technology are discussed. Combined tests with other sub-detectors are finally addressed. This test beam program is inserted in the framework of the EUDET European project. Keywords. New generation of silicon tracking; new sensors; large area tracking systems.

  4. New developments of the R & D silicon tracking for linear collider on ...

    Indian Academy of Sciences (India)

    Keywords. New generation of silicon tracking; new sensors; large area tracking systems for international linear collider; deep sub-micron electronics. ... are discussed. Combined tests with other sub-detectors are finally addressed. This test beam program is inserted in the framework of the EUDET European project.

  5. Dry etch method for texturing silicon and device

    Science.gov (United States)

    Gershon, Talia S.; Haight, Richard A.; Kim, Jeehwan; Lee, Yun Seog

    2017-07-25

    A method for texturing silicon includes loading a silicon wafer into a vacuum chamber, heating the silicon wafer and thermal cracking a gas to generate cracked sulfur species. The silicon wafer is exposed to the cracked sulfur species for a time duration in accordance with a texture characteristic needed for a surface of the silicon wafer.

  6. Mechanical Properties and Microstructure of Biomorphic Silicon Carbide Ceramics Fabricated from Wood Precursors

    Science.gov (United States)

    Singh, Mrityunjay; Salem, J. A.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Silicon carbide based, environment friendly, biomorphic ceramics have been fabricated by the pyrolysis and infiltration of natural wood (maple and mahogany) precursors. This technology provides an eco-friendly route to advanced ceramic materials. These biomorphic silicon carbide ceramics have tailorable properties and behave like silicon carbide based materials manufactured by conventional approaches. The elastic moduli and fracture toughness of biomorphic ceramics strongly depend on the properties of starting wood preforms and the degree of molten silicon infiltration. Mechanical properties of silicon carbide ceramics fabricated from maple wood precursors indicate the flexural strengths of 3441+/-58 MPa at room temperature and 230136 MPa at 1350C. Room temperature fracture toughness of the maple based material is 2.6 +/- 0.2 MPa(square root of)m while the mahogany precursor derived ceramics show a fracture toughness of 2.0 +/- 0.2 Mpa(square root of)m. The fracture toughness and the strength increase as the density of final material increases. Fractographic characterization indicates the failure origins to be pores and chipped pockets of silicon.

  7. High temperature mechanical performance of a hot isostatically pressed silicon nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, A.A.; Ferber, M.K.; Jenkins, M.G.; Lin, C.K.J. [and others

    1996-01-01

    Silicon nitride ceramics are an attractive material of choice for designers and manufacturers of advanced gas turbine engine components for many reasons. These materials typically have potentially high temperatures of usefulness (up to 1400{degrees}C), are chemically inert, have a relatively low specific gravity (important for inertial effects), and are good thermal conductors (i.e., resistant to thermal shock). In order for manufacturers to take advantage of these inherent properties of silicon nitride, the high-temperature mechanical performance of the material must first be characterized. The mechanical response of silicon nitride to static, dynamic, and cyclic conditions at elevated temperatures, along with reliable and representative data, is critical information that gas turbine engine designers and manufacturers require for the confident insertion of silicon nitride components into gas turbine engines. This final report describes the high-temperature mechanical characterization and analyses that were conducted on a candidate structural silicon nitride ceramic. The high-temperature strength, static fatigue (creep rupture), and dynamic and cyclic fatigue performance were characterized. The efforts put forth were part of Work Breakdown Structure Subelement 3.2.1, {open_quotes}Rotor Data Base Generation.{close_quotes} PY6 is comparable to other hot isostatically pressed (HIPed) silicon nitrides currently being considered for advanced gas turbine engine applications.

  8. Status and Prospect of Test Methods of Quality Silicone Water Repellent for Protecting Reinforced Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Sun, H. Y.; Yuan, Z. Y.; Yang, Z.; Shan, G. L. [Nanjing Hydraulic Research Institute, Nanjing (China); Shen, M. X. [Hehai University, Nanjing (China)

    2017-06-15

    Impregnating with quality silicone water repellent on the concrete surface is an effective method of protecting concrete. Quality silicone water repellent has been widely used in the engineering profession because of its desirable properties such as hydrophobicity, keeping concrete breathable and preserving the original appearance of the concrete. The companies in China that produce silicone water repellent are listed. Test methods in the specifications or standards about silicone water repellent in China are summed. The test methods relative to durability of concrete impregnated with silicone water repellent (such as resistant to chloride ion penetration, resistant to alkali, resistance to freezing and thawing and weather ability etc.) and the constructive quality (such as water absorption rate, impregnating depth and the dry velocity coefficient etc.) are compared and analyzed. The results indicate that there are differences among test methods relative to different specifications with the same index and therefore, confusion has ensued when selecting test methods. All test methods with the exception of the method of water absorption rate by using a Karsten flask are not non-destructive methods or conducted in a laboratory. Finally, further research on silicone water repellent during application is proposed.

  9. Enhancement of heat transfer in Czochralski growth of silicon crystals with a chemical cooling technique

    Science.gov (United States)

    Ding, Junling; Liu, Lijun; Zhao, Wenhan

    2017-06-01

    The cost of producing single-crystalline silicon with the Czochralski method can be reduced by promoting the crystal size and/or crystal pulling rate. However, more latent heat of solidification needs to be released from the melt-crystal (m-c) interface during the crystal growth process. In this study, the C-CO2 chemical endothermic reaction is proposed as a novel and efficient cooling technique to solve this problem. Compared with the conventional gas cooling method, C-CO2 endothermic reaction method can significantly enhance the heat transfer in the crystal at the m-c interface. It was found that the heat transfer is more enhanced with a chemical reaction of smaller activation energy, and the m-c interface becomes flatter. The influence of the carbon concentration in the chemical reactive gas flow on the heat removal in the crystal at the m-c interface is also investigated. The cooling effect is significantly increased with the increase in the carbon concentration when it is small. However, when the carbon concentration in the reactive gas is high, the cooling effect just increases slightly. The research demonstrates that the proposed chemical endothermic reaction is a promising cooling technique to be applied in CZ-Si crystal growth with large size/high pulling rate.

  10. Characterisation of Silicon Pad Diodes

    CERN Document Server

    Hodson, Thomas Connor

    2017-01-01

    Silicon pad sensors are used in high luminosity particle detectors because of their excellent timing resolution, radiation tolerance and possible high granularity. The effect of different design decisions on detector performance can be investigated nondestructively through electronic characterisation of the sensor diodes. Methods for making accurate measurements of leakage current and cell capacitance are described using both a standard approach with tungsten needles and an automated approach with a custom multiplexer and probing setup.

  11. Spectroscopy of single silicon nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.; Cichos, F.; Borczyskowski, C. von E-mail: borczyskowski@physik.tu-chemnitz.de

    2004-06-01

    Confocal microscopy has been performed on silicon nanoparticles prepared by gas-phase methods and electrochemical etching (single particles), respectively. Spectral line narrowing has been obtained for single particles. Spectra are in agreement with interstellar extended red emission (ERE) when properly choosing size distributions. Independent of preparation techniques, both types show similar behaviour with respect to (partly reversible in the dark) photobleaching accompanied by spectral red shifts on timescales of seconds upon 514 nm laser irradiation.

  12. Coating of silicon pore optics

    DEFF Research Database (Denmark)

    Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland

    2009-01-01

    For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates...

  13. The ATLAS Silicon Pixel Sensors

    CERN Document Server

    Alam, M S; Einsweiler, K F; Emes, J; Gilchriese, M G D; Joshi, A; Kleinfelder, S A; Marchesini, R; McCormack, F; Milgrome, O; Palaio, N; Pengg, F; Richardson, J; Zizka, G; Ackers, M; Andreazza, A; Comes, G; Fischer, P; Keil, M; Klasen, V; Kühl, T; Meuser, S; Ockenfels, W; Raith, B; Treis, J; Wermes, N; Gössling, C; Hügging, F G; Wüstenfeld, J; Wunstorf, R; Barberis, D; Beccherle, R; Darbo, G; Gagliardi, G; Gemme, C; Morettini, P; Musico, P; Osculati, B; Parodi, F; Rossi, L; Blanquart, L; Breugnon, P; Calvet, D; Clemens, J-C; Delpierre, P A; Hallewell, G D; Laugier, D; Mouthuy, T; Rozanov, A; Valin, I; Aleppo, M; Caccia, M; Ragusa, F; Troncon, C; Lutz, Gerhard; Richter, R H; Rohe, T; Brandl, A; Gorfine, G; Hoeferkamp, M; Seidel, SC; Boyd, GR; Skubic, P L; Sícho, P; Tomasek, L; Vrba, V; Holder, M; Ziolkowski, M; D'Auria, S; del Papa, C; Charles, E; Fasching, D; Becks, K H; Lenzen, G; Linder, C

    2001-01-01

    Prototype sensors for the ATLAS silicon pixel detector have been developed. The design of the sensors is guided by the need to operate them in the severe LHC radiation environment at up to several hundred volts while maintaining a good signal-to-noise ratio, small cell size, and minimal multiple scattering. The ability to be operated under full bias for electrical characterization prior to the attachment of the readout integrated circuit electronics is also desired.

  14. Silicon nanocrystals as handy biomarkers

    Science.gov (United States)

    Fujioka, Kouki; Hoshino, Akiyoshi; Manabe, Noriyoshi; Futamura, Yasuhiro; Tilley, Richard; Yamamoto, Kenji

    2007-02-01

    Quantum dots (QDs) have brighter and longer fluorescence than organic dyes. Therefore, QDs can be applied to biotechnology, and have capability to be applied to medical technology. Currently, among the several types of QDs, CdSe with a ZnS shell is one of the most popular QDs to be used in biological experiments. However, when the CdSe QDs were applied to clinical technology, potential toxicological problems due to CdSe core should be considered. To eliminate the problem, silicon nanocrystals, which have the potential of biocompatibility, could be a candidate of alternate probes. Silicon nanocrystals have been synthesized using several techniques such as aerosol, electrochemical etching, laser pyrolysis, plasma deposition, and colloids. Recently, the silicon nanocrystals were reported to be synthesized in inverse micelles and also stabilized with 1-heptene or allylamine capping. Blue fluorescence of the nanocrystals was observed when excited with a UV light. The nanocrystals covered with 1-heptene are hydrophobic, whereas the ones covered with allylamine are hydrophilic. To test the stability in cytosol, the water-soluble nanocrystals covered with allylamine were examined with a Hela cell incorporation experiment. Bright blue fluorescence of the nanocrystals was detected in the cytosol when excited with a UV light, implying that the nanocrystals were able to be applied to biological imaging. In order to expand the application range, we synthesized and compared a series of silicon nanocrystals, which have variable surface modification, such as alkyl group, alcohol group, and odorant molecules. This study will provide a wider range of optoelectronic applications and bioimaging technology.

  15. Purity of silicon: with great effect on its performance in graphite-silicon anode materials for lithium-ion batteries

    Science.gov (United States)

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

    2017-09-01

    Ferrosilicon, industrial grade silicon, solar grade silicon, and electronic grade silicon were ball-milled to form four types of silicon powders, which were mixed with graphite powders at weight ratio of 5:95, respectively, for being used as graphite-silicon anode materials in lithium-ion batteries (LIBs). The effect of the purity of silicon on its electrochemical performance in graphite-silicon anode materials for LIBs was investigated by the cycle and rate tests. Results show that silicon with higher purity shows higher capacity, better cycle, and rate performance. In addition, the significant difference in capacity of the four graphite-silicon anodes with different purities of silicon is not completely resulted from the content of silicon materials, and the influence of the impurity inside the silicon cannot be ignored as well. The sample prepared from electronic grade silicon presents the highest first discharge capacity, which is 440.5 mAh g-1.

  16. Modeling Indirect Tunneling in Silicon

    Science.gov (United States)

    Chen, Edward

    Indirect tunneling in silicon p-n junctions catches people's attention again in recent years. First, the phenomenon induces a serious leakage problem, so called gate-induced drain leakage (GIDL) effect, in modern metal-oxide-semiconductor field-effect transistors (MOSFETs). Second, it is utilized to develop a novel tunneling transistor with the sharp turn-on ability for continuing ITRS roadmap. Although the indirect tunneling is important for the state-of-the-art transistor-technology, the accuracy of the present tunneling models in technology computer-aided design (TCAD) tools is still vague. In the research work, the theory of indirect tunneling in silicon has been thoroughly studied. The phonon-assisted tunneling model has been developed and compared with the existing ones in the Sentaurus-Synopsys, Medici-Synopsys, and Atlas-Silvaco TCAD tools. Beyond these existing models, ours successfully predicts the indirect tunneling current under the different field direction in silicon. In addition, bandgap narrowing in heavily-doped p-n junctions under the reverse-biased condition is also studied during the model development. At the end of the research work, the application to low standby power (LSTP) transistors is demonstrated to show the capability of our tunneling model in the device level.

  17. Casting larger polycrystalline silicon ingots

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Tomlinson, T.; Cliber, J.; Shea, S.; Narayanan, M.

    1995-08-01

    Solarex has developed and patented a directional solidification casting process specifically designed for photovoltaics. In this process, silicon feedstock is melted in a ceramic crucible and solidified into a large grained semicrystalline silicon ingot. In-house manufacture of low cost, high purity ceramics is a key to the low cost fabrication of Solarex polycrystalline wafers. The casting process is performed in Solarex designed casting stations. The casting operation is computer controlled. There are no moving parts (except for the loading and unloading) so the growth process proceeds with virtually no operator intervention Today Solarex casting stations are used to produce ingots from which 4 bricks, each 11.4 cm by 11.4 cm in cross section, are cut. The stations themselves are physically capable of holding larger ingots, that would yield either: 4 bricks, 15 cm by 15 an; or 9 bricks, 11.4 cm by 11.4 an in cross-section. One of the tasks in the Solarex Cast Polycrystalline Silicon PVMaT Program is to design and modify one of the castings stations to cast these larger ingots. If successful, this effort will increase the production capacity of Solarex`s casting stations by 73% and reduce the labor content for casting by an equivalent percentage.

  18. Waveguiding Light into Silicon Oxycarbide

    Directory of Open Access Journals (Sweden)

    Faisal Ahmed Memon

    2017-05-01

    Full Text Available In this work, we demonstrate the fabrication of single mode optical waveguides in silicon oxycarbide (SiOC with a high refractive index n = 1.578 on silica (SiO2, exhibiting an index contrast of Δn = 8.2%. Silicon oxycarbide layers were deposited by reactive RF magnetron sputtering of a SiC target in a controlled process of argon and oxygen gases. The optical properties of SiOC film were measured with spectroscopic ellipsometry in the near-infrared range and the acquired refractive indices of the film exhibit anisotropy on the order of 10−2. The structure of the SiOC films is investigated with atomic force microscopy (AFM and scanning electron microscopy (SEM. The channel waveguides in SiOC are buried in SiO2 (n = 1.444 and defined with UV photolithography and reactive ion etching techniques. Propagation losses of about 4 dB/cm for both TE and TM polarizations at telecommunication wavelength 1550 nm are estimated with cut-back technique. Results indicate the potential of silicon oxycarbide for guided wave applications.

  19. The DAMPE silicon tungsten tracker

    CERN Document Server

    Gallo, Valentina; Asfandiyarov, R; Azzarello, P; Bernardini, P; Bertucci, B; Bolognini, A; Cadoux, F; Caprai, M; Domenjoz, M; Dong, Y; Duranti, M; Fan, R; Franco, M; Fusco, P; Gargano, F; Gong, K; Guo, D; Husi, C; Ionica, M; Lacalamita, N; Loparco, F; Marsella, G; Mazziotta, M N; Mongelli, M; Nardinocchi, A; Nicola, L; Pelleriti, G; Peng, W; Pohl, M; Postolache, V; Qiao, R; Surdo, A; Tykhonov, A; Vitillo, S; Wang, H; Weber, M; Wu, D; Wu, X; Zhang, F; De Mitri, I; La Marra, D

    2017-01-01

    The DArk Matter Particle Explorer (DAMPE) satellite has been successfully launched on the 17th December 2015. It is a powerful space detector designed for the identification of possible Dark Matter signatures thanks to its capability to detect electrons and photons with an unprecedented energy resolution in an energy range going from few GeV up to 10 TeV. Moreover, the DAMPE satellite will contribute to a better understanding of the propagation mechanisms of high energy cosmic rays measuring the nuclei flux up to 100 TeV. DAMPE is composed of four sub-detectors: a plastic strip scintillator, a silicon-tungsten tracker-converter (STK), a BGO imaging calorimeter and a neutron detector. The STK is made of twelve layers of single-sided AC-coupled silicon micro-strip detectors for a total silicon area of about 7 $m^2$ . To promote the conversion of incident photons into electron-positron pairs, tungsten foils are inserted into the supporting structure. In this document, a detailed description of the STK constructi...

  20. 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.

  1. Silicon quantum dot superlattice solar cell structure including silicon nanocrystals in a photogeneration layer.

    Science.gov (United States)

    Yamada, Shigeru; Kurokawa, Yasuyoshi; Miyajima, Shinsuke; Konagai, Makoto

    2014-01-01

    The solar cell structure of n-type poly-silicon/5-nm-diameter silicon nanocrystals embedded in an amorphous silicon oxycarbide matrix (30 layers)/p-type hydrogenated amorphous silicon/Al electrode was fabricated on a quartz substrate. An open-circuit voltage and a fill factor of 518 mV and 0.51 in the solar cell were obtained, respectively. The absorption edge of the solar cell was 1.49 eV, which corresponds to the optical bandgap of the silicon nanocrystal materials, suggesting that it is possible to fabricate the solar cells with silicon nanocrystal materials, whose bandgaps are wider than that of crystalline silicon. 85.35.Be; 84.60.Jt; 78.67.Bf.

  2. Silicon nanostructures in silicon oxynitride for PV application: effect of argon

    Energy Technology Data Exchange (ETDEWEB)

    Ehrhardt, Fabien; Ferblantier, Gerald; Muller, Dominique; Slaoui, Abdelilah [Institut d' Electronique du Solide et des Systemes, UMR CNRS-UdS 7163, 23 Rue du Loess, BP20, 67034 Strasbourg cedex 2 (France); Ulhaq-Bouillet, Corinne [Institut de Physique et Chimie des Materiaux de Strasbourg, UMR CNRS-UdS 7504, 23 Rue du Loess, BP43, 67034 Strasbourg cedex 2 (France)

    2012-10-15

    Silicon rich silicon oxynitride (SRSON) were deposited by ECR-PECVD to form silicon nanostructures. The effect of argon flow during the deposition was investigated. The silicon nanoparticles were fabricated by a classical thermal treatment of SRSON films. The structural properties of the SRSON films were investigated by RBS and FTIR measurements. We show that the silicon excess in the SiO{sub x}N{sub y} matrix changes slightly with Ar flow but it has a significant impact on the silicon nanoparticles morphology embedded in the silicon oxynitride layer. Different shapes for silicon nanostructures ranging from separated Si nanocrystals to Si nanocolumns were formed as studied by energy-filtred transmission electron microscopy analysis (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Single-Event Effects in Silicon and Silicon Carbide Power Devices

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

    2014-01-01

    NASA Electronics Parts and Packaging program-funded activities over the past year on single-event effects in silicon and silicon carbide power devices are presented, with focus on SiC device failure signatures.

  4. Development of Radiation Hard Radiation Detectors, Differences between Czochralski Silicon and Float Zone Silicon

    CERN Document Server

    Tuominen, Eija

    2012-01-01

    The purpose of this work was to develop radiation hard silicon detectors. Radiation detectors made ofsilicon are cost effective and have excellent position resolution. Therefore, they are widely used fortrack finding and particle analysis in large high-energy physics experiments. Silicon detectors willalso be used in the CMS (Compact Muon Solenoid) experiment that is being built at the LHC (LargeHadron Collider) accelerator at CERN (European Organisation for Nuclear Research). This work wasdone in the CMS programme of Helsinki Institute of Physics (HIP).Exposure of the silicon material to particle radiation causes irreversible defects that deteriorate theperformance of the silicon detectors. In HIP CMS Programme, our approach was to improve theradiation hardness of the silicon material with increased oxygen concentration in silicon material. Westudied two different methods: diffusion oxygenation of Float Zone silicon and use of high resistivityCzochralski silicon.We processed, characterised, tested in a parti...

  5. Signal development in irradiated silicon detectors

    CERN Document Server

    Kramberger, Gregor; Mikuz, Marko

    2001-01-01

    This work provides a detailed study of signal formation in silicon detectors, with the emphasis on detectors with high concentration of irradiation induced defects in the lattice. These defects give rise to deep energy levels in the band gap. As a consequence, the current induced by charge motion in silicon detectors is signifcantly altered. Within the framework of the study a new experimental method, Charge correction method, based on transient current technique (TCT) was proposed for determination of effective electron and hole trapping times in irradiated silicon detectors. Effective carrier trapping times were determined in numerous silicon pad detectors irradiated with neutrons, pions and protons. Studied detectors were fabricated on oxygenated and non-oxygenated silicon wafers with different bulk resistivities. Measured effective carrier trapping times were found to be inversely proportional to fuence and increase with temperature. No dependence on silicon resistivity and oxygen concentration was observ...

  6. Ultrafast Terahertz Conductivity of Photoexcited Nanocrystalline Silicon

    DEFF Research Database (Denmark)

    Cooke, David; MacDonald, A. Nicole; Hryciw, Aaron

    2007-01-01

    The ultrafast transient ac conductivity of nanocrystalline silicon films is investigated using time-resolved terahertz spectroscopy. While epitaxial silicon on sapphire exhibits a free carrier Drude response, silicon nanocrystals embedded in glass show a response that is best described by a class......The ultrafast transient ac conductivity of nanocrystalline silicon films is investigated using time-resolved terahertz spectroscopy. While epitaxial silicon on sapphire exhibits a free carrier Drude response, silicon nanocrystals embedded in glass show a response that is best described...... by a classical Drude–Smith model, suitable for disorder-driven metal–insulator transitions. In this work, we explore the time evolution of the frequency dependent complex conductivity after optical injection of carriers on a picosecond time scale. Furthermore, we show the lifetime of photoconductivity...

  7. Analytical and Experimental Evaluation of Joining Silicon Carbide to Silicon Carbide and Silicon Nitride to Silicon Nitride for Advanced Heat Engine Applications Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, G.J.

    1994-01-01

    Techniques were developed to produce reliable silicon nitride to silicon nitride (NCX-5101) curved joins which were used to manufacture spin test specimens as a proof of concept to simulate parts such as a simple rotor. Specimens were machined from the curved joins to measure the following properties of the join interlayer: tensile strength, shear strength, 22 C flexure strength and 1370 C flexure strength. In parallel, extensive silicon nitride tensile creep evaluation of planar butt joins provided a sufficient data base to develop models with accurate predictive capability for different geometries. Analytical models applied satisfactorily to the silicon nitride joins were Norton's Law for creep strain, a modified Norton's Law internal variable model and the Monkman-Grant relationship for failure modeling. The Theta Projection method was less successful. Attempts were also made to develop planar butt joins of siliconized silicon carbide (NT230).

  8. Fabrication of 25 μm-filter microfluidic chip on silicon substrate

    Science.gov (United States)

    Ngan Le, Nguyen; Khanh Huynh, Kim; Cam Hue Phan, Thi; Dung Dang, Thi My; Chien Dang, Mau

    2017-03-01

    This paper presents the entire fabrication process including photolithography, sputtering, deep reactive ion etching (Bosch DRIE process) on silicon substrate and bonding process between the lid and silicon substrate to create a designed filtration microfluidic chip with dimension of 28 mm × 7 mm, one inlet port and one outlet port. A pattered silver thin film was deposited on a silicon sample by the lift-off method. Subsequently the newly fabricated sample was anisotropically etched by Bosch DRIE process. Some parameters of Bosch DRIE process such as bias power, duration of etching step and passivation step, oxygen presence were studied to explore the dependence of silicon channel depth and etched shape profile on these parameters. An optimized process was utilized to fabricate a featured silicon channel with vertical, smooth sidewalls and an overall good uniformity. The silicon channel has four arrays of microposts with various distances between microposts from 25 μm to 100 μm. The depth of the silicon channel was about 150 μm. After that, silicon substrate was bonded with mica lid by adhesive bonding method to form the completed filtration microfluidic chip. The samples were characterized by scanning electron microscopy (SEM), mechanical profilometer (DEKTAK 6 M), optical microscopy (Olympus MX51). In this paper a test was performed to demonstrate how the microfluidic chip works by pumping solution with many various sizes of particles through the inlet port of the microfluidic chip and obtaining a solution with desired particles sizes (smaller than 25 μm) through another port. Moreover, the chip could be pumped de-ionized water through outlet port for backwash in order to make this microfluidic chip reusable. Finally, a few applications of microfluidic chips are presented to illustrate the advantages of this technology and the potential for future development. Invited talk at 8th International Workshop on Advanced Materials Science and Nanotechnology

  9. Aluminum-catalyzed silicon nanowires: Growth methods, properties, and applications

    Energy Technology Data Exchange (ETDEWEB)

    Hainey, Mel F.; Redwing, Joan M. [Department of Materials Science and Engineering, Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2016-12-15

    Metal-mediated vapor-liquid-solid (VLS) growth is a promising approach for the fabrication of silicon nanowires, although residual metal incorporation into the nanowires during growth can adversely impact electronic properties particularly when metals such as gold and copper are utilized. Aluminum, which acts as a shallow acceptor in silicon, is therefore of significant interest for the growth of p-type silicon nanowires but has presented challenges due to its propensity for oxidation. This paper summarizes the key aspects of aluminum-catalyzed nanowire growth along with wire properties and device results. In the first section, aluminum-catalyzed nanowire growth is discussed with a specific emphasis on methods to mitigate aluminum oxide formation. Next, the influence of growth parameters such as growth temperature, precursor partial pressure, and hydrogen partial pressure on nanowire morphology is discussed, followed by a brief review of the growth of templated and patterned arrays of nanowires. Aluminum incorporation into the nanowires is then discussed in detail, including measurements of the aluminum concentration within wires using atom probe tomography and assessment of electrical properties by four point resistance measurements. Finally, the use of aluminum-catalyzed VLS growth for device fabrication is reviewed including results on single-wire radial p-n junction solar cells and planar solar cells fabricated with nanowire/nanopyramid texturing.

  10. Aluminum-catalyzed silicon nanowires: Growth methods, properties, and applications

    Science.gov (United States)

    Hainey, Mel F.; Redwing, Joan M.

    2016-12-01

    Metal-mediated vapor-liquid-solid (VLS) growth is a promising approach for the fabrication of silicon nanowires, although residual metal incorporation into the nanowires during growth can adversely impact electronic properties particularly when metals such as gold and copper are utilized. Aluminum, which acts as a shallow acceptor in silicon, is therefore of significant interest for the growth of p-type silicon nanowires but has presented challenges due to its propensity for oxidation. This paper summarizes the key aspects of aluminum-catalyzed nanowire growth along with wire properties and device results. In the first section, aluminum-catalyzed nanowire growth is discussed with a specific emphasis on methods to mitigate aluminum oxide formation. Next, the influence of growth parameters such as growth temperature, precursor partial pressure, and hydrogen partial pressure on nanowire morphology is discussed, followed by a brief review of the growth of templated and patterned arrays of nanowires. Aluminum incorporation into the nanowires is then discussed in detail, including measurements of the aluminum concentration within wires using atom probe tomography and assessment of electrical properties by four point resistance measurements. Finally, the use of aluminum-catalyzed VLS growth for device fabrication is reviewed including results on single-wire radial p-n junction solar cells and planar solar cells fabricated with nanowire/nanopyramid texturing.

  11. McCarter superfinish grinding for silicon -- an update.

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, F.; Khounsary, A.; McCarter, D.; Krasnicki, F.; Tangedahl, M.

    2000-11-03

    A grinding technique, referred to as the McCarter Superfinish, for grinding large size optical components is discussed and certain surface characterization information about flatness and the relative magnitude of the subsurface damage in silicon substrates is reported. The flatness measurements were obtained with a Zygo surface analyzer, and the substrate damage measurements were made by x-ray diffraction and acid etching. Results indicate excellent control of flatness and fine surface finish. X-ray measurements show that the diamond wheels with small particle sizes used in the final phases of the grinding operation renders surfaces with relatively small subsurface damage.

  12. Silicon Photonics Platform for Government Applications

    Science.gov (United States)

    2016-03-31

    high difference in refractive index that allows the silicon to guide light around relatively sharp bends, facilitating devices with dimensions in the...978-1-4799-5380-6/15/$31.00 ©2015 IEEE Silicon Photonics Platform for Government Applications Anthony L. Lentine, Christopher T. DeRose, Paul...Labs PO Box 5800 MS1082 Albuquerque, NM 87185 505-284-1736 alentine@sandia.gov Abstract—   We review Sandia’s silicon photonics platform

  13. Silicon-based nanochannel glucose sensor

    OpenAIRE

    Wang, Xihua; Chen, Yu; Gibney, Katherine A.; Erramilli, Shyamsunder; Mohanty, Pritiraj

    2008-01-01

    Silicon nanochannel biological field effect transistors have been developed for glucose detection. The device is nanofabricated from a silicon-on-insulator wafer with a top-down approach and surface functionalized with glucose oxidase. The differential conductance of silicon nanowires, tuned with source-drain bias voltage, is demonstrated to be sensitive to the biocatalyzed oxidation of glucose. The glucose biosensor response is linear in the 0.5-8 mM concentration range with 3-5 min response...

  14. Silicon Photomultiplier - New Era of Photon Detection

    OpenAIRE

    Saveliev, Valeri

    2010-01-01

    Silicon photomultipliers is novel type of the semiconductor photodetector for the detecting of low photon flux. Already now the technology is developed and suitable for many critical application as medical imaging, and biology, homeland security, optic communications, experimental physics and military applications. Few world well known companies Hamamatsu, Sensl, Kotura are already producing or close to production of silicon photomultiplier type sensors. Near future of silicon photomultiplier...

  15. Silicon Light: a European FP7 project aiming at high efficiency thin film silicon solar cells on foil. Monolithic series interconnection of flexible thin-film PV devices

    Energy Technology Data Exchange (ETDEWEB)

    Soppe, W. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Haug, F.J. [Ecole Polytechnique Federale de Lausanne EPFL, Photovoltaics and Thin Film Electronics Laboratory, Rue A.-L. Breguet 2, 2000 Neuchatel (Switzerland); Couty, P. [VHFTechnologies SA, Rue Edouard-Verdan 2, CH-1400 Yverdon-les-Bains (Switzerland); Duchamp, M. [Technical University of Denmark, Center for Electron Nanoscopy, DK-2800 Kongens Lyngby (Denmark); Schipper, W. [Nanoptics GmbH, Innungstr.5, 21244 Buchholz (Germany); Krc, J. [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia); Sanchez, G. [Universidad Politecnica de Valencia, I.U.I. Centro de Tecnologia Nanofotonica, 46022 Valencia (Spain); Leitner, K. [Umicore Thin Film Products AG, Balzers (Liechtenstein); Wang, Q. [Shanghai Jiaotong University, Research Institute of Micro/Nanometer Science and Technology, 800 Dongchuan Road, Min Hang, 200240 Shanghai (China)

    2011-09-15

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: (a) advanced light trapping by implementing nanotexturization through UV Nano Imprinting Lithography (UV-NIL); (b) growth of crack-free silicon absorber layers on highly textured substrates; (c) development of new TCOs which should combine the best properties of presently available materials like ITO and AZO. The paper presents the midterm status of the project results, showing model calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils with nanotexture is shown. Microcrystalline and amorphous silicon single junction cells with stable efficiencies with more than 8% have been made, paving the way towards a-Si/{mu}c-Si tandem cells with more than 11% efficiency.

  16. Silicon and oxygen isotopic trends in Mesozoic radiolarites

    Science.gov (United States)

    Bôle, Maximlien; Baumgartner Peter, O.; Lukas, Baumgartner; Anne-Sophie, Bouvier; Rie, Hori; Masayuki, Ikeda

    2016-04-01

    the main extractors of light silicon in the oceans and lead to a δ30Si increase of the remaining ocean water reservoir. Rivers furnish the main supply of fresh silicon to the ocean but climate and exposed source rocks may determine the silicon isotopic composition of river water. Measurements of δ30Si in ocean water depth profiles were successful in characterizing watermasses of the Antarctic Ocean. Finally, proximity from continents may also contribute to the observed trends. Near continents, high productivity may lead to high δ30Si, whereas light, recycled silicon may be more important in locations far from continents. This recycled silicon should be relatively light considering that it results from biogenic and dissolution fractionation which are both negative. These factors might affect also the difference in δ30Si-trends of radiolarites between Panthalassa and western Tethys.

  17. Silicon photonics for telecommunications and biomedicine

    CERN Document Server

    Fathpour, Sasan

    2011-01-01

    Given silicon's versatile material properties, use of low-cost silicon photonics continues to move beyond light-speed data transmission through fiber-optic cables and computer chips. Its application has also evolved from the device to the integrated-system level. A timely overview of this impressive growth, Silicon Photonics for Telecommunications and Biomedicine summarizes state-of-the-art developments in a wide range of areas, including optical communications, wireless technologies, and biomedical applications of silicon photonics. With contributions from world experts, this reference guides

  18. Solar cell with silicon oxynitride dielectric layer

    Science.gov (United States)

    Shepherd, Michael; Smith, David D

    2015-04-28

    Solar cells with silicon oxynitride dielectric layers and methods of forming silicon oxynitride dielectric layers for solar cell fabrication are described. For example, an emitter region of a solar cell includes a portion of a substrate having a back surface opposite a light receiving surface. A silicon oxynitride (SiO.sub.xN.sub.y, 0silicon oxynitride dielectric layer.

  19. Silicon Micromachined Microlens Array for THz Antennas

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, IImran; Gill, John J.; Jung-Kubiak, Cecile D.; Llombart, Nuria

    2013-01-01

    5 5 silicon microlens array was developed using a silicon micromachining technique for a silicon-based THz antenna array. The feature of the silicon micromachining technique enables one to microfabricate an unlimited number of microlens arrays at one time with good uniformity on a silicon wafer. This technique will resolve one of the key issues in building a THz camera, which is to integrate antennas in a detector array. The conventional approach of building single-pixel receivers and stacking them to form a multi-pixel receiver is not suited at THz because a single-pixel receiver already has difficulty fitting into mass, volume, and power budgets, especially in space applications. In this proposed technique, one has controllability on both diameter and curvature of a silicon microlens. First of all, the diameter of microlens depends on how thick photoresist one could coat and pattern. So far, the diameter of a 6- mm photoresist microlens with 400 m in height has been successfully microfabricated. Based on current researchers experiences, a diameter larger than 1-cm photoresist microlens array would be feasible. In order to control the curvature of the microlens, the following process variables could be used: 1. Amount of photoresist: It determines the curvature of the photoresist microlens. Since the photoresist lens is transferred onto the silicon substrate, it will directly control the curvature of the silicon microlens. 2. Etching selectivity between photoresist and silicon: The photoresist microlens is formed by thermal reflow. In order to transfer the exact photoresist curvature onto silicon, there needs to be etching selectivity of 1:1 between silicon and photoresist. However, by varying the etching selectivity, one could control the curvature of the silicon microlens. The figure shows the microfabricated silicon microlens 5 x5 array. The diameter of the microlens located in the center is about 2.5 mm. The measured 3-D profile of the microlens surface has a

  20. Silicon solid state devices and radiation detection

    CERN Document Server

    Leroy, Claude

    2012-01-01

    This book addresses the fundamental principles of interaction between radiation and matter, the principles of working and the operation of particle detectors based on silicon solid state devices. It covers a broad scope with respect to the fields of application of radiation detectors based on silicon solid state devices from low to high energy physics experiments including in outer space and in the medical environment. This book covers stateof- the-art detection techniques in the use of radiation detectors based on silicon solid state devices and their readout electronics, including the latest developments on pixelated silicon radiation detector and their application.

  1. High breakdown-strength composites from liquid silicone rubbers

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Zakaria, Shamsul Bin; Yu, Liyun

    2014-01-01

    In this paper we investigate the performance of liquid silicone rubbers (LSRs) as dielectric elastomer transducers. Commonly used silicones in this application include room-temperature vulcanisable (RTV) silicone elastomers and composites thereof. Pure LSRs and their composites with commercially...

  2. Development of Solar Grade (SoG) Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, David B; Schmid, Frederick

    2008-01-18

    , as well as liners and coatings to allow the vacuum to be achieved. These developments also hold the promise of lower cost ingot growth, because several of these developments led to a reusable crucible. Liners and coatings were tested on 37 runs, under a variety of conditions. Although many of these did not fulfill the requirements of the program, several were very successful, particularly in allowing the crucible to be reused several times. The most interesting result was with slags and additives used to reduce P and Al. Although slags have been much studied with little success in removing P and B effectively, certain modeling suggested a particular type of slagging might be effective. This was tried, and found to be highly effective for P and surprisingly effective for B, as well. The best results indicate that > 99% of the P was removed, and > 75% of the B was removed by a slagging treatment. An operability issue involving separation of the slag and silicon was the final technical problem preventing the full-scale use of this technique, and there has been progress on this front. A slagging/additive technique is highly promising, because the rates of equilibration are very high, and this is a rapid technique that scales very well to large volumes with little increase in time. Materials of containment and slag/metal separation are issues that are continuing to be developed.

  3. Silicon and boron differ in their localization and loading in bone

    Directory of Open Access Journals (Sweden)

    Ravin Jugdaohsingh

    2015-01-01

    Full Text Available Silicon and boron share many similarities, both chemically and biochemically, including having similar effects on bone, although their mechanisms of action are not known. Here we compared the loading of silicon and boron into bone, their localization and how they are influenced by age (growth & development, to obtain further clues as to the biological effects of these elements and, especially, to see if they behave the same or not. Bone samples were obtained from two different studies where female Sprague Dawley rats had been maintained on a normal maintenance diet for up to 43 weeks. Total bone elemental levels were determined by ICP-OES following microwave assisted acid digestion. Silicon and boron levels in the decalcified bones (i.e. the collagen fraction were also investigated. Silicon and boron showed marked differences in loading and in their localization in bone. Highest silicon and lowest boron concentrations were found in the under-mineralized bone of younger rats and lowest silicon and highest boron concentrations were found in the fully mineralized bone of the adult rat. Overall, however total bone silicon content increased with age, as did boron content, the latter mirroring the increase in calcium (mineral content of bone. However, whereas silicon showed equal distribution in the collagen and mineral fractions of bone, boron was exclusively localized in the mineral fraction. These findings confirm the reported association between silicon and collagen, especially at the early stages of bone mineralization, and show that boron is associated with the bone mineral but not connective tissues. These data suggest that silicon and boron have different biological roles and that one is unlikely, therefore, to substitute for the other, or at least boron would not substitute for Si in the connective tissues. Finally, we noted that silicon levels in the mineral fraction varied greatly between the two studies, suggesting that one or more

  4. Low temperature surface passivation for silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Leguijt, C.; Loelgen, P.; Eikelboom, J.A.; Weeber, A.W.; Schuurmans, F.M.; Sinke, W.C. [Netherlands Energy Research Foundation ECN, Petten (Netherlands); Alkemade, P.F.A.; Sarro, P.M. [Delft Institute for MicroElectronics and Submicron Technology DIMES, Delft (Netherlands); Maree, C.H.M. [Department of Atomic and Interface Physics, Debye Institute, University of Utrecht, Utrecht (Netherlands); Verhoef, L.A. [R and S Renewable Energy Systems B.V., Helmond (Netherlands)

    1996-07-18

    Surface passivation at low processing temperatures becomes an important topic for cheap solar cell processing. In this study, we first give a broad overview of the state of the art in this field. Subsequently, the results of a series of mutually related experiments are given about surface passivation with direct Plasma Enhanced Chemical Vapour Deposition (PECVD) of silicon oxide (Si-oxide) and silicon nitride (Si-nitride). Results of harmonically modulated microwave reflection experiments are combined with Capacitance-Voltage measurements on Metal-Insulator-Silicon structures (CV-MIS), accelerated degradation tests and with Secondary Ion Mass Spectrometry (SIMS) and Elastic Recoil Detection (ERD) measurements of hydrogen and deuterium concentrations in the passivating layers. A large positive fixed charge density at the interface is very important for the achieved low surface recombination velocities S. The density of interface states D{sub i}t is strongly reduced by post deposition anneals. The lowest values of S are obtained with PECVD of Si-nitride. The surface passivation obtained with Si-nitride is stable under typical operating conditions for solar cells. By using deuterium as a tracer it is shown that hydrogen in the ambient of the post deposition anneal does not play a role in the passivation by Si-nitride. Finally, the results of CV-MIS measurements on deposited Si-nitride layers are used to calculate effective recombination velocities as a function of the injection level at the surface, using a model that is able to predict the surface recombination velocity S at thermally oxidized silicon surfaces. These results are not in agreement with the measured increase of S at low injection levels

  5. Systemic Sclerosis and Silicone Breast Implant: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Antonios Psarras

    2014-01-01

    Full Text Available Environmentally induced systemic sclerosis is a well-recognized condition, which is correlated with exposure to various chemical compounds or drugs. However, development of scleroderma-like disease after exposure to silicone has always been a controversial issue and, over time, it has triggered spirited debate whether there is a certain association or not. Herein, we report the case of a 35-year-old female who developed Raynaud’s phenomenon and, finally, systemic sclerosis shortly after silicone breast implantation surgery.

  6. Development of a silicone ablator for high-heat-flux and high-shear-rate condition

    Science.gov (United States)

    Campbell, R. A.; Ramseyer, J. A.; Huntress, A.

    1972-01-01

    A silicone material was developed which gives suitable ablative protection in the high heat flux, high shear environments encountered in severe reentry applications, such as nose cones for ballistic vehicles and protection of leading edges or other critical areas of a vehicle. In addition, the ease of handling, low application cost, and room temperature cure make such a silicon material suitable nozzles for the large rockets necessary for vehicle launching. The development of this product is traced from the selection of suitable polymers through the choice of fillers and the finalization of filler loadings.

  7. Progress on the Dow Corning process for solar-grade silicon

    Science.gov (United States)

    Hunt, L. P.; Dosaj, V. D.

    1979-01-01

    The Dow Corning approach to increasing the resistivity of solar-grade silicon from about 0.04 ohm-cm (40 ppma B) to greater than 0.1 ohm-cm (10 ppma B) involves the use of high-purity raw materials carbothermically reduced in a specially designed electric arc furnace. Final purification occurs during Czochralski crystal growth of a polycrystalline ingot. This small-scale purification technology has resulted in silicon that has been fabricated into solar cells with a maximum AM1 conversion efficiency of 13.4%.

  8. Stand-alone Cosmic Muon Reconstruction Before Installation of the CMS Silicon Strip Tracker

    CERN Document Server

    Adam, W; Dragicevic, M; Friedl, M; Fruhwirth, R; Hansel, S; Hrubec, J; Krammer, M; Oberegger, M; Pernicka, M; Schmid, S; Stark, RS; Steininger, H; Uhl, D; Waltenberger, W; Widl, E; Van Mechelen, P; Cardaci, M; Beaumont, W; de Langhe, E; de Wolf, E A; Delmeire, E; Hashemi, M; Bouhali, O; Charaf, O; Clerbaux, B; Dewulf, J P; Elgammal, S; Hammad, G; de Lentdecker, G; Marage, P; Vander Velde, C; Vanlaer, P; Wickens, J; Adler, V; Devroede, O; De Weirdt, S; D'Hondt, J; Goorens, R; Heyninck, J; Maes, J; Mozer, M; Tavernier, S; Van Lancker, L; Van Mulders, P; Villella, I; Wastiels, C; Bonnet, J L; Bruno, G; De Callatay, B; Florins, B; Giammanco, A; Gregoire, G; Keutgen, Th; Kcira, D; Lemaitre, V; Michotte, D; Militaru, O; Piotrzkowski, K; Quertermont, L; Roberfroid, V; Rouby, X; Teyssier, D; Daubie, E; Anttila, E; Czellar, S; Engstrom, P; Harkonen, J; Karimaki, V; Kostesmaa, J; Kuronen, A; Lampen, T; Linden, T; Luukka, P R; Maenpaa, T; Michal, S; Tuominen, E; Tuominiemi, J; Ageron, M; Baulieu, G; Bonnevaux, A; Boudoul, G; Chabanat, E; Chabert, E; Chierici, R; Contardo, D; Della Negra, R; Dupasquier, T; Gelin, G; Giraud, N; Guillot, G; Estre, N; Haroutunian, R; Lumb, N; Perries, S; Schirra, F; Trocme, B; Vanzetto, S; Agram, J L; Blaes, R; Drouhin, F; Ernenwein, J P; Fontaine, J C; Berst, J D; Brom, J M; Didierjean, F; Goerlach, U; Graehling, P; Gross, L; Hosselet, J; Juillot, P; Lounis, A; Maazouzi, C; Olivetto, C; Strub, R; Van Hove, P; Anagnostou, G; Brauer, R; Esser, H; Feld, L; Karpinski, W; Klein, K; Kukulies, C; Olzem, J; Ostapchuk, A; Pandoulas, D; Pierschel, G; Raupach, F; Schael, S; Schwering, G; Sprenger, D; Thomas, M; Weber, M; Wittmer, B; Wlochal, M; Beissel, F; Bock, E; Flugge, G; Gillissen, C; Hermanns, T; Heydhausen, D; Jahn, D; Kaussen, G; Linn, A; Perchalla, L; Poettgens, M; Pooth, O; Stahl, A; Zoeller, M H; Buhmann, P; Butz, E; Flucke, G; Hamdorf, R; Hauk, J; Klanner, R; Pein, U; Schleper, P; Steinbruck, G; Blum, P; De Boer, W; Dierlamm, A; Dirkes, G; Fahrer, M; Frey, M; Furgeri, A; Hartmann, F; Heier, S; Hoffmann, K H; Kaminski, J; Ledermann, B; Liamsuwan, T; Muller, S; Muller, Th; Schilling, F P; Simonis, H J; Steck, P; Zhukov, V; Cariola, P; De Robertis, G; Ferorelli, R; Fiore, L; Preda, M; Sala, G; Silvestris, L; Tempesta, P; Zito, G; Creanza, D; De Filippis, N; De Palma, M; Giordano, D; Maggi, G; Manna, N; My, S; Selvaggi, G; Albergo, S; Chiorboli, M; Costa, S; Galanti, M; Giudice, N; Guardone, N; Noto, F; Potenza, R; Saizu, M A; Sparti, V; Sutera, C; Tricomi, A; Tuve, C; Brianzi, M; Civinini, C; Maletta, F; Manolescu, F; Meschini, M; Paoletti, S; Sguazzoni, G; Broccolo, B; Ciulli, V; D'Alessandro, R; Focardi, E; Frosali, S; Genta, C; Landi, G; Lenzi, P; Macchiolo, A; Magini, N; Parrini, G; Scarlini, E; Cerati, G; Azzi, P; Bacchetta, N; Candelori, A; Dorigo, T; Kaminsky, A; Karaevski, S; Khomenkov, V; Reznikov, S; Tessaro, M; Bisello, D; De Mattia, M; Giubilato, P; Loreti, M; Mattiazzo, S; Nigro, M; Paccagnella, A; Pantano, D; Pozzobon, N; Tosi, M; Bilei, G M; Checcucci, B; Fano, L; Servoli, L; Ambroglini, F; Babucci, E; Benedetti, D; Biasini, M; Caponeri, B; Covarelli, R; Giorgi, M; Lariccia, P; Mantovani, G; Marcantonini, M; Postolache, V; Santocchia, A; Spiga, D; Bagliesi, G; Balestri, G; Berretta, L; Bianucci, S; Boccali, T; Bosi, F; Bracci, F; Castaldi, R; Ceccanti, M; Cecchi, R; Cerri, C; Cucoanes, A S; Dell'Orso, R; Dobur, D; Dutta, S; Giassi, A; Giusti, S; Kartashov, D; Kraan, A; Lomtadze, T; Lungu, G A; Magazzu, G; Mammini, P; Mariani, F; Martinelli, G; Moggi, A; Palla, F; Palmonari, F; Petragnani, G; Profeti, A; Raffaelli, F; Rizzi, D; Sanguinetti, G; Sarkar, S; Sentenac, D; Serban, A T; Slav, A; Soldani, A; Spagnolo, P; Tenchini, R; Tolaini, S; Venturi, A; Verdini, P G; Vos, M; Zaccarelli, L; Avanzini, C; Basti, A; Benucci, L; Bocci, A; Cazzola, U; Fiori, F; Linari, S; Massa, M; Messineo, A; Segneri, G; Tonelli, G; Azzurri, P; Bernardini, J; Borrello, L; Calzolari, F; Foa, L; Gennai, S; Ligabue, F; Petrucciani, G; Rizzi, A; Yang, Z; Benotto, F; Demaria, N; Dumitrache, F; Farano, R; Borgia, M A; Castello, R; Costa, M; Migliore, E; Romero, A; Abbaneo, D; Abbas, M; Ahmed, I; Akhtar, I; Albert, E; Bloch, C; Breuker, H; Butt, S; Buchmuller, O; Cattai, A; Delaere, C; Delattre, M; Edera, L M; Engstrom, P; Eppard, M; Gateau, M; Gill, K; Giolo-Nicollerat, A S; Grabit, R; Honma, A; Huhtinen, M; Kloukinas, K; Kortesmaa, J; Kottelat, L J; Kuronen, A; Leonardo, N; Ljuslin, C; Mannelli, M; Masetti, L; Marchioro, A; Mersi, S; Michal, S; Mirabito, L; Muffat-Joly, J; Onnela, A; Paillard, C; Pal, I; Pernot, J F; Petagna, P; Petit, P; Piccut, C; Pioppi, M; Postema, H; Ranieri, R; Ricci, D; Rolandi, G; Ronga, F; Sigaud, C; Syed, A; Siegrist, P; Tropea, P; Troska, J; Tsirou, A; Vander Donckt, M; Vasey, F; Alagoz, E; Amsler, C; Chiochia, V; Regenfus, Christian; Robmann, P; Rochet, J; Rommerskirchen, T; Schmidt, A; Steiner, S; Wilke, L; Church, I; Cole, J; Coughlan, J; Gay, A; Taghavi, S; Tomalin, I; Bainbridge, R; Cripps, N; Fulcher, J; Hall, G; Noy, M; Pesaresi, M; Radicci, V; Raymond, D M; Sharp, P; Stoye, M; Wingham, M; Zorba, O; Goitom, I; Hobson, P R; Reid, I; Teodorescu, L; Hanson, G; Jeng, G Y; Liu, H; Pasztor, G; Satpathy, A; Stringer, R; Mangano, B; Affolder, K; Affolder, T; Allen, A; Barge, D; Burke, S; Callahan, D; Campagnari, C; Crook, A; D'Alfonso, M; Dietch, J; Garberson, Jeffrey Ford; Hale, D; Incandela, H; Incandela, J; Jaditz, S; Kalavase, P; Kreyer, S; Kyre, S; Lamb, J; Mc Guinness, C; Mills, C; Nguyen, H; Nikolic, M; Lowette, S; Rebassoo, F; Ribnik, J; Richman, J; Rubinstein, N; Sanhueza, S; Shah, Y; Simms, L; Staszak, D; Stoner, J; Stuart, D; Swain, S; Vlimant, J R; White, D; Ulmer, K A; Wagner, S R; Bagby, L; Bhat, P C; Burkett, K; Cihangir, S; Gutsche, O; Jensen, H; Johnson, M; Luzhetskiy, N; Mason, D; Miao, T; Moccia, S; Noeding, C; Ronzhin, A; Skup, E; Spalding, W J; Spiegel, L; Tkaczyk, S; Yumiceva, F; Zatserklyaniy, A; Zerev, E; Anghel, I; Bazterra, V E; Gerber, C E; Khalatian, S; Shabalina, E; Baringer, P; Bean, A; Chen, J; Hinchey, C; Martin, C; Moulik, T; Robinson, R; Gritsan, A V; Lae, C K; Tran, N V; Everaerts, P; Hahn, K A; Harris, P; Nahn, S; Rudolph, M; Sung, K; Betchart, B; Demina, R; Gotra, Y; Korjenevski, S; Miner, D; Orbaker, D; Christofek, L; Hooper, R; Landsberg, G; Nguyen, D; Narain, M; Speer, T; Tsang, K V

    2009-01-01

    The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15% of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses.

  9. Texture evolution of experimental silicon steel grades. Part I: Hot rolling

    OpenAIRE

    Sandoval Robles, J. A.; Salas Zamarripa, A.; Martha P. Guerrero Mata; Cabrera Marrero, José M.

    2017-01-01

    The metallurgical understanding of the deformation processes during the fabrication of non-oriented electrical steels plays a key role in improving their final properties. Texture control and optimization is critical in these steels for the enhancement of their magnetic properties. The aim of the present work is to study the texture evolution of six non-oriented experimental silicon steel grades during hot rolling. These steels were low carbon steel with a silicon content from 0.5 to 3.0 wt%....

  10. Hot Electron Injection into Uniaxially Strained Silicon

    Science.gov (United States)

    Kim, Hyun Soo

    In semiconductor spintronics, silicon attracts great attention due to the long electron spin lifetime. Silicon is also one of the most commonly used semiconductor in microelectronics industry. The spin relaxation process of diamond crystal structure such as silicon is dominant by Elliot-Yafet mechanism. Yafet shows that intravalley scattering process is dominant. The conduction electron spin lifetime measured by electron spin resonance measurement and electronic measurement using ballistic hot electron method well agrees with Yafet's theory. However, the recent theory predicts a strong contribution of intervalley scattering process such as f-process in silicon. The conduction band minimum is close the Brillouin zone edge, X point which causes strong spin mixing at the conduction band. A recent experiment of electric field-induced hot electron spin relaxation also shows the strong effect of f-process in silicon. In uniaxially strained silicon along crystal axis [100], the suppression of f-process is predicted which leads to enhance electron spin lifetime. By inducing a change in crystal structure due to uniaxial strain, the six fold degeneracy becomes two fold degeneracy, which is valley splitting. As the valley splitting increases, intervalley scattering is reduced. A recent theory predicts 4 times longer electron spin lifetime in 0.5% uniaxially strained silicon. In this thesis, we demonstrate ballistic hot electron injection into silicon under various uniaxial strain. Spin polarized hot electron injection under strain is experimentally one of the most challenging part to measure conduction electron spin lifetime in silicon. Hot electron injection adopts tunnel junction which is a thin oxide layer between two conducting materials. Tunnel barrier, which is an oxide layer, is only 4 ˜ 5 nm thick. Also, two conducting materials are only tens of nanometer. Therefore, under high pressure to apply 0.5% strain on silicon, thin films on silicon substrate can be easily

  11. Emerging heterogeneous integrated photonic platforms on silicon

    Directory of Open Access Journals (Sweden)

    Fathpour Sasan

    2015-05-01

    Full Text Available Silicon photonics has been established as a mature and promising technology for optoelectronic integrated circuits, mostly based on the silicon-on-insulator (SOI waveguide platform. However, not all optical functionalities can be satisfactorily achieved merely based on silicon, in general, and on the SOI platform, in particular. Long-known shortcomings of silicon-based integrated photonics are optical absorption (in the telecommunication wavelengths and feasibility of electrically-injected lasers (at least at room temperature. More recently, high two-photon and free-carrier absorptions required at high optical intensities for third-order optical nonlinear effects, inherent lack of second-order optical nonlinearity, low extinction ratio of modulators based on the free-carrier plasma effect, and the loss of the buried oxide layer of the SOI waveguides at mid-infrared wavelengths have been recognized as other shortcomings. Accordingly, several novel waveguide platforms have been developing to address these shortcomings of the SOI platform. Most of these emerging platforms are based on heterogeneous integration of other material systems on silicon substrates, and in some cases silicon is integrated on other substrates. Germanium and its binary alloys with silicon, III–V compound semiconductors, silicon nitride, tantalum pentoxide and other high-index dielectric or glass materials, as well as lithium niobate are some of the materials heterogeneously integrated on silicon substrates. The materials are typically integrated by a variety of epitaxial growth, bonding, ion implantation and slicing, etch back, spin-on-glass or other techniques. These wide range of efforts are reviewed here holistically to stress that there is no pure silicon or even group IV photonics per se. Rather, the future of the field of integrated photonics appears to be one of heterogenization, where a variety of different materials and waveguide platforms will be used for

  12. Emerging heterogeneous integrated photonic platforms on silicon

    Science.gov (United States)

    Fathpour, Sasan

    2015-05-01

    Silicon photonics has been established as a mature and promising technology for optoelectronic integrated circuits, mostly based on the silicon-on-insulator (SOI) waveguide platform. However, not all optical functionalities can be satisfactorily achieved merely based on silicon, in general, and on the SOI platform, in particular. Long-known shortcomings of silicon-based integrated photonics are optical absorption (in the telecommunication wavelengths) and feasibility of electrically-injected lasers (at least at room temperature). More recently, high two-photon and free-carrier absorptions required at high optical intensities for third-order optical nonlinear effects, inherent lack of second-order optical nonlinearity, low extinction ratio of modulators based on the free-carrier plasma effect, and the loss of the buried oxide layer of the SOI waveguides at mid-infrared wavelengths have been recognized as other shortcomings. Accordingly, several novel waveguide platforms have been developing to address these shortcomings of the SOI platform. Most of these emerging platforms are based on heterogeneous integration of other material systems on silicon substrates, and in some cases silicon is integrated on other substrates. Germanium and its binary alloys with silicon, III-V compound semiconductors, silicon nitride, tantalum pentoxide and other high-index dielectric or glass materials, as well as lithium niobate are some of the materials heterogeneously integrated on silicon substrates. The materials are typically integrated by a variety of epitaxial growth, bonding, ion implantation and slicing, etch back, spin-on-glass or other techniques. These wide range of efforts are reviewed here holistically to stress that there is no pure silicon or even group IV photonics per se. Rather, the future of the field of integrated photonics appears to be one of heterogenization, where a variety of different materials and waveguide platforms will be used for different purposes with

  13. Theoretical studies of H-passivated silicon nanowires, silicon surface systems and silicon/germanium core/shell nanowires

    Science.gov (United States)

    Lu, Ning

    Global structural optimization with Genetic Algorithm and first principle analysis have been performed on the Silicon nanowires, Ag induced Si surface reconstruction systems and Si/Ge core/shell nanowires. By using genetic algorithm combined with ab-initio calculation, we determined the atomic structures H-passivated and silicon nanowires. We found that at certain values of the hydrogen chemical potential the nanowires can take relatively stable structures in SiNWs with rectangular cross sections bounded by monohydride {110} and {111} facets with dihydride wire edges. In SiNWs cross section of the nanowire evolves from chains of six-atom rings to fused pairs of such chains to hexagons bounded by {001} and {111} facets. Second, with the structural models of SiNWs, we further analyzed their electronic properties. We showed that the SiNWs have an indirect to quasi-direct band gap transition with the increasing sizes and the band gap properties under uniaxial stress and different aspect ratios. Third, we did a Ag-induced Si(111) (rt3xrt3) and (3x1) surface reconstruction search with our variablenumber GA with ab-initio relaxation. The (rt3xrt3) global search found the Inequivalent Triangle (IET) structure as the lowest energy. A model of combination of pure Ag films and IET structure is proposed to explain the islands-to-holes ratio (RIH) equals 3 situation observed in experiments. For the (3x1) reconstruction, a model with 2/3 ML Ag and 1Ml Si coverage has been found and it has lower surface energy than the widely accepted HCC model with only 1/3 ML Ag coverage. Finally, we did some DFT calculation on the Si/Ge and Ge/Si core/shell [112] nanowires. The charged localization inside the NWs reveals that the electrons and holes are seperated. The quantum confinement effect in the NWs is strongly modified by the band offsets. An indirect to quasi-direct band gap transition can be obtained with a compressive strain, and the depth of the quantum wells can be modulated by the

  14. Crystal growth and evaluation of silicon for VLSI and ULSI

    CERN Document Server

    Eranna, Golla

    2014-01-01

    PrefaceAbout the AuthorIntroductionSilicon: The SemiconductorWhy Single CrystalsRevolution in Integrated Circuit Fabrication Technology and the Art of Device MiniaturizationUse of Silicon as a SemiconductorSilicon Devices for Boolean ApplicationsIntegration of Silicon Devices and the Art of Circuit MiniaturizationMOS and CMOS Devices for Digital ApplicationsLSI, VLSI, and ULSI Circuits and ApplicationsSilicon for MEMS ApplicationsSummaryReferencesSilicon: The Key Material for Integrated Circuit Fabrication TechnologyIntroductionPreparation of Raw Silicon MaterialMetallurgical-Grade SiliconPuri

  15. Partitioning Effects in Recrystallization of Silicon from Silicon-Metal Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Good, E. A.; Wang, T. H.; Ciszek, T. F.; Frost, R. H.; Page, M. R.; Landry, M. D.

    2002-08-01

    The objective of this work is to investigate various silicon-metal eutectic systems that selectively retain detrimental impurities, such as Ni, Co, Fe, Cr, in the melt so that silicon may be purified. We studied possible interactions in the melt and in the silicon crystal between impurity elements and solvent metals that lead to reduced or enhanced impurity partition relative to the respective silicon-impurity binary systems. Systems such as Al- Si, Cu-Si, and In-Si show promises of reduced impurity incorporations in recrystallized silicon, which are good candidates for further investigation besides Ga-Si, Au-Si, and Ag-Si.

  16. The STAR silicon vertex tracker: a large area silicon drift detector

    CERN Document Server

    Lynn, D; Beuttenmüller, Rolf H; Caines, H; Chen, W; Dimassimo, D; Dyke, H; Elliot, D; Eremin, V; Grau, M; Hoffmann, G W; Humanic, T; Ilyashenko, Yu S; Kotov, I; Kraner, H W; Kuczewski, P; Leonhardt, B; Li, Z; Liaw, C J; Lo Curto, G; Middelkamp, P; Minor, R; Munhoz, M; Ott, G; Pandey, S U; Pruneau, C A; Rykov, V L; Schambach, J; Sedlmeir, J; Soja, B; Sugarbaker, E R; Takahashi, J; Wilson, K; Wilson, R

    2000-01-01

    The Solenoidal Tracker At RHIC-Silicon Vertex Tracker (STAR-SVT) is a three barrel microvertex detector based upon silicon drift detector technology. As designed for the STAR-SVT, silicon drift detectors (SDDs) are capable of providing unambiguous two-dimensional hit position measurements with resolutions on the order of 20 mu m in each coordinate. Achievement of such resolutions, particularly in the drift direction coordinate, depends upon certain characteristics of silicon and drift detector geometry that are uniquely critical for silicon drift detectors hit measurements. Here we describe features of the design of the STAR-SVT SDDs and the front-end electronics that are motivated by such characteristics.

  17. Toward quantitative modeling of silicon phononic thermocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Lacatena, V. [STMicroelectronics, 850, rue Jean Monnet, F-38926 Crolles (France); IEMN UMR CNRS 8520, Institut d' Electronique, de Microélectronique et de Nanotechnologie, Avenue Poincaré, F-59652 Villeneuve d' Ascq (France); Haras, M.; Robillard, J.-F., E-mail: jean-francois.robillard@isen.iemn.univ-lille1.fr; Dubois, E. [IEMN UMR CNRS 8520, Institut d' Electronique, de Microélectronique et de Nanotechnologie, Avenue Poincaré, F-59652 Villeneuve d' Ascq (France); Monfray, S.; Skotnicki, T. [STMicroelectronics, 850, rue Jean Monnet, F-38926 Crolles (France)

    2015-03-16

    The wealth of technological patterning technologies of deca-nanometer resolution brings opportunities to artificially modulate thermal transport properties. A promising example is given by the recent concepts of 'thermocrystals' or 'nanophononic crystals' that introduce regular nano-scale inclusions using a pitch scale in between the thermal phonons mean free path and the electron mean free path. In such structures, the lattice thermal conductivity is reduced down to two orders of magnitude with respect to its bulk value. Beyond the promise held by these materials to overcome the well-known “electron crystal-phonon glass” dilemma faced in thermoelectrics, the quantitative prediction of their thermal conductivity poses a challenge. This work paves the way toward understanding and designing silicon nanophononic membranes by means of molecular dynamics simulation. Several systems are studied in order to distinguish the shape contribution from bulk, ultra-thin membranes (8 to 15 nm), 2D phononic crystals, and finally 2D phononic membranes. After having discussed the equilibrium properties of these structures from 300 K to 400 K, the Green-Kubo methodology is used to quantify the thermal conductivity. The results account for several experimental trends and models. It is confirmed that the thin-film geometry as well as the phononic structure act towards a reduction of the thermal conductivity. The further decrease in the phononic engineered membrane clearly demonstrates that both phenomena are cumulative. Finally, limitations of the model and further perspectives are discussed.

  18. Fabrication of thick silicon nitride blocks embedded in low-resistivity silicon substrates for radio frequency applications

    OpenAIRE

    Fernandez, L.J.; Berenschot, Johan W.; Wiegerink, Remco J.; Flokstra, Jakob; Flokstra, Jan; Jansen, Henricus V.; Elwenspoek, Michael Curt

    2006-01-01

    Thick silicon nitride blocks embedded in silicon wafers were recently proposed as a substrate for RF devices. In this paper we show that deep trenches filled with silicon nitride—having thin slices of monocrystalline silicon in between—already result in a significantly improved RF behavior. Measurement results are presented on RF coplanar waveguides using solid silicon nitride blocks and silicon nitride filled trenches with various dimensions and orientations with respect to the transmission ...

  19. Effect of Silicon Nanowire on Crystalline Silicon Solar Cell Characteristics

    Directory of Open Access Journals (Sweden)

    Zahra Ostadmahmoodi Do

    2016-06-01

    Full Text Available Nanowires (NWs are recently used in several sensor or actuator devices to improve their ordered characteristics. Silicon nanowire (Si NW is one of the most attractive one-dimensional nanostructures semiconductors because of its unique electrical and optical properties. In this paper, silicon nanowire (Si NW, is synthesized and characterized for application in photovoltaic device. Si NWs are prepared using wet chemical etching method which is commonly used as a simple and low cost method for producing nanowires of the same substrate material. The process conditions are adjusted to find the best quality of Si NWs. Morphology of Si NWs is studied using a field emission scanning electron microscopic technique. An energy dispersive X-Ray analyzer is also used to provide elemental identification and quantitative compositional information. Subsequently, Schottky type solar cell samples are fabricated on Si and Si NWs using ITO and Ag contacts. The junction properties are calculated using I-V curves in dark condition and the solar cell I-V characteristics are obtained under incident of the standardized light of AM1.5. The results for the two mentioned Schottky solar cell samples are compared and discussed. An improvement in short circuit current and efficiency of Schottky solar cell is found when Si nanowires are employed.

  20. Optical manipulation of silicon nanowires on silicon nitride waveguides

    Science.gov (United States)

    Néel, D.; Gétin, S.; Fedeli, J.-M.; Baron, T.; Gentile, P.; Ferret, P.

    2007-01-01

    Semiconductor nanowires are drawing more and more interest due to their numerous potential applications in nanoelectronics devices [1,2], including interconnects, transistor channels, nanoelectrodes, or in the emerging application areas of photonics [3], chemistry [4] and photovoltaics [5]. In this context, optical tweezers appear like a pertinent tool for the manipulation and assembly of nanowires into complex structures. It was previously shown that the near-field existing at the surface of a waveguide allows the micromanipulation of nanoparticles and biological objects [6,7]. In this article, we investigate for the first time to our knowledge the motion of silicon nanowires above silicon nitride waveguides. The nanowires in aqueous solution are attracted toward the waveguide by optical gradient forces. The nanowires align themselves according to the axis of the waveguide and get propelled along the waveguide due to radiation pressure. Velocities are up to 40 μm/s. For a better understanding of the experimental results, the distribution of the electromagnetic field in the nanowire is calculated using the finite element method. Then, the resulting optical forces exerted on the nanowires are calculated, thanks to the Maxwell stress tensor formalism.