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Sample records for svx ii silicon

  1. The CDF-II silicon tracking system

    Energy Technology Data Exchange (ETDEWEB)

    F. Palmonari et al.

    2002-01-18

    The CDFII silicon tracking system, SVX, for Run II of the Fermilab Tevatron has up to 8 cylindrical layers with average radii spanning from {approx} (1.5 to 28.7) cm, and lengths ranging from {approx} (90 to 200) cm for a total active-area of {approx} 6 m{sup 2} and {approx} 7.2 x 10{sup 5} readout channels. SVX will improve the CDFII acceptance and efficiency for both B and high-Pt physics dependent upon b-tagging. Along with the description of the SVX we report some alignment survey data from the SVX assembly phase and the actual status of the alignment as it results from the offline data analysis. The problems encountered are also reviewed.

  2. Evaluation of FOXFET biased ac-coupled silicon strip detector prototypes for CDF SVX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Laakso, M. (Fermi National Accelerator Lab., Batavia, IL (United States) Research Inst. for High Energy Physics (SEFT), Helsinki (Finland))

    1992-03-01

    Silicon microstrip detectors for high-precision charged particle position measurements have been used in nuclear and particle physics for years. The detectors have evolved from simple surface barrier strip detectors with metal strips to highly complicated double-sided AC-coupled junction detectors. The feature of AC-coupling the readout electrodes from the diode strips necessitates the manufacture of a separate biasing structure for the strips, which comprises a common bias line together with a means for preventing the signal from one strip from spreading to its neighbors through the bias line. The obvious solution to this is to bias the strips through individual high value resistors. These resistors can be integrated on the detector wafer by depositing a layer of resistive polycrystalline silicon and patterning it to form the individual resistors. To circumvent the extra processing step required for polysilicon resistor processing and the rather difficult tuning of the process to obtain uniform and high enough resistance values throughout the large detector area, alternative methods for strip biasing have been devised. These include the usage of electron accumulation layer resistance for N{sup +}{minus} strips or the usage of the phenomenon known as the punch-through effect for P{sup +}{minus} strips. In this paper we present measurement results about the operation and radiation resistance of detectors with a punch-through effect based biasing structure known as a Field OXide Field-Effect Transistor (FOXFET), and present a model describing the FOXFET behavior. The studied detectors were prototypes for detectors to be used in the CDF silicon vertex detector upgrade.

  3. Preliminary test results for the SVX4

    Energy Technology Data Exchange (ETDEWEB)

    Christofek, L.; Hanagaki, K.; Rapidis, P.; Utes, M.; /Fermilab

    2005-06-01

    We present and summarize the preliminary test results for SVX4 chip testing. There are presently two versions of the SVX4. Version 2 has on-chip bypassing and Version 1 does not. The on-chip bypassing is a layer of transistors under the front-end analog pipeline that acts as a bypassing capacitor for the voltage supply. Its size is about a microfarad. We aggressively choose to test Version 2 because of this feature. The feature is advantageous for hybrid design because it eliminates the need for an additional passive component on the hybrid itself by placing it on the actual SVX4 die. Also, the SVX4 was designed to operate in two modes: D. and CDF. One can set which mode the chip will operate by placing a jumper in the proper position on the SVX4 chip carrier. In either mode, the chip can either use the operating parameters from the shift register or the shadow register. Similarly, this is selected by placing a jumper on the SVX4 chip carrier. This chip has this feature because it was unknown whether the new design of the shadow register would be operable. The shadow register is also call the SEU register or Single Event Upset register. An introduction into the functionality of the chip and an explanation on the difference between D. and CDF mode can be found in the SVX4 User's Manual [1].

  4. SVX4: A New Deep-Submicron Readout IC for the Tevatron Collider at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Krieger, B.; Alfonsi, S.; Bacchetta, N.; Centro, S.; Christofek, L.; Garcia-Sciveres, M.; Haber, C.; Hanagaki, K.; Hoff, J.; Johnson, M.; vonderLippe, H.; Lujan, P.; Mandelli, E.; Meng, G.; Nomerotski, A.; Pellet, D.; Rapidis, P.; Utes, M.; Walder, J.-P.; Weber, M.; Wester, W.; /LBL, Berkeley /Padua U. /INFN, Padua /Kansas U. /Fermilab /UC,

    2003-10-01

    SVX4 is the new silicon strip readout IC designed to meet the increased radiation tolerance requirements for Run IIb at the Tevatron collider. Devices have been fabricated, tested, and approved for production. The SVX4 design is a technology migration of the SVX3D design currently in use by CDF. Whereas SVX3D was fabricated in a 0.8 {micro}m radiation-hard process, SVX4 was fabricated in a standard 0.25 {micro}m mixed-signal CMOS technology using the ''radiation tolerant by design'' transistor topologies devised by the RD-49 collaboration. The specific cell layouts include digital cells developed by the ATLAS Pixel group, and full-custom analog blocks. Unlike its predecessors, the new design also includes the necessary features required for generic use by both the CDF and D0 experiments at Fermilab. Performance of the IC includes >20 MRad total dose tolerance, and {approx}2000 e-rms equivalent input noise charge with 40 pF input capacitance, when sampled at 132 ns period with an 80 ns preamp risetime. At the nominal digitize/readout rate of 106/53 MHz, the 9 mm x 6.3 mm die dissipates {approx}2 mW/channel average at 2.5 V. A review of typical operation, details of the design conversion process, and performance measurements are covered.

  5. SVX4 a new deep submicron readout IC for the Tevatron Collider at Fermilab

    CERN Document Server

    Krieger, B; Bacchetta, N; Centro, Sandro; Christofek, L; García-Sciveres, M; Haber, C; Hanagaki, K; Hoff, J; Johnson, M; Von der Lippe, H; Mandelli, E; Meng, G; Nomerotski, A; Pellet, D; Rapidis, P; Utes, M; Walder, J P; Weber, M; Wester, W; Wilkes, T; Yarema, R J; Yao, W; Zimmerman, T

    2004-01-01

    SVX4 is the new silicon strip readout IC designed to meet the increased radiation tolerance requirements for Run IIb at the Tevatron collider. Devices have been fabricated, tested, and approved for production. The SVX4 design is a technology migration of the SVX3D design currently in use by CDF. Whereas SVX3D was fabricated in a 0.8 mu m radiation-hard process, SVX4 was fabricated in a standard 0.25 mu m mixed-signal CMOS technology using the "radiation tolerant by design" transistor topologies devised by the RD-49 collaboration. The specific cell layouts include digital cells developed by the ATLAS Pixel group, and full-custom analog blocks. Unlike its predecessors, the new design also includes the necessary features required for generic use by both the CDF and DO experiments at Fermilab. Performance of the IC includes >20 Mrad total dose tolerance, and ~2000 e- rms equivalent input noise charge with 40 pF input capacitance, when sampled at 132 ns period with an 80 ns preamp risetime. At the nominal digitize...

  6. Measurement of SEU cross sections in the CDF SVX3 ASIC using 63 MeV protons

    CERN Document Server

    Grim, G P; Gay, C; Hill, C; Nahn, S; Pellett, D E; Pope, G; Shepard, P F; Slaughter, A J; Wester, W C

    2000-01-01

    The single event upset (SEU) cross section has been measured for 63 MeV protons incident on static memory cells in the CDF SVX3 pipelined silicon strip readout ASIC. The device was fabricated in the Honeywell 0.8 mu m RICMOS IV bulk process, and contains a number of cells with minimum gate length transistors to control the mode of operation of the chip. Cross sections per cell of (4.4+-1.8)x10 sup - sup 1 sup 6 cm sup 2 , (2.1+-0.7)x10 sup - sup 1 sup 5 cm sup 2 , and (3.9+-0.9)x10 sup - sup 1 sup 5 cm sup 2 were measured for angles of incidence of 0 deg. , 45 deg. , and 80 deg. , respectively, for cells with 0.8 mu m gate length. The SVX3 SEU rate in Run II at the Fermilab Tevatron was estimated to be sufficiently low that it would not affect the performance of the CDF Silicon Tracker.

  7. 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

  8. Silicon Photonics II Components and Integration

    CERN Document Server

    Lockwood, David J

    2011-01-01

    This book is volume II of a series of books on silicon photonics. It gives a fascinating picture of the state-of-the-art in silicon photonics from a component perspective. It presents a perspective on what can be expected in the near future. It is formed from a selected number of reviews authored by world leaders in the field, and is written from both academic and industrial viewpoints. An in-depth discussion of the route towards fully integrated silicon photonics is presented. This book will be useful not only to physicists, chemists, materials scientists, and engineers but also to graduate students who are interested in the fields of micro- and nanophotonics and optoelectronics.

  9. The Belle II Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, M., E-mail: markus.friedl@oeaw.ac.at [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Ackermann, K. [MPI Munich, Föhringer Ring 6, 80805 München (Germany); Aihara, H. [University of Tokyo, Department of Physics, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Aziz, T. [Tata Institute of Fundamental Research, Experimental High Energy Physics Group, Homi Bhabha Road, Mumbai 400 005 (India); Bergauer, T. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Bozek, A. [Institute of Nuclear Physics, Division of Particle Physics and Astrophysics, ul. Radzikowskiego 152, 31 342 Krakow (Poland); Campbell, A. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Dingfelder, J. [University of Bonn, Department of Physics and Astronomy, Nussallee 12, 53115 Bonn (Germany); Drasal, Z. [Charles University, Institute of Particle and Nuclear Physics, Ke Karlovu 3, 121 16 Praha 2 (Czech Republic); Frankenberger, A. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Gadow, K. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Gfall, I. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Haba, J.; Hara, K.; Hara, T. [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Higuchi, T. [University of Tokyo, Kavli Institute for Physics and Mathematics of the Universe, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Himori, S. [Tohoku University, Department of Physics, Aoba Aramaki Aoba-ku, Sendai 980-8578 (Japan); Irmler, C. [HEPHY – Institute of High Energy Physics, Nikolsdorfer Gasse 18, 1050 Vienna (Austria); Ishikawa, A. [Tohoku University, Department of Physics, Aoba Aramaki Aoba-ku, Sendai 980-8578 (Japan); Joo, C. [Seoul National University, High Energy Physics Laboratory, 25-107 Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of); and others

    2013-12-21

    The KEKB machine and the Belle experiment in Tsukuba (Japan) are now undergoing an upgrade, leading to an ultimate luminosity of 8×10{sup 35}cm{sup −2}s{sup −1} in order to measure rare decays in the B system with high statistics. The previous vertex detector cannot cope with this 40-fold increase of luminosity and thus needs to be replaced. Belle II will be equipped with a two-layer Pixel Detector surrounding the beam pipe, and four layers of double-sided silicon strip sensors at higher radii than the old detector. The Silicon Vertex Detector (SVD) will have a total sensitive area of 1.13m{sup 2} and 223,744 channels—twice as many as its predecessor. All silicon sensors will be made from 150 mm wafers in order to maximize their size and thus to reduce the relative contribution of the support structure. The forward part has slanted sensors of trapezoidal shape to improve the measurement precision and to minimize the amount of material as seen by particles from the vertex. Fast-shaping front-end amplifiers will be used in conjunction with an online hit time reconstruction algorithm in order to reduce the occupancy to the level of a few percent at most. A novel “Origami” chip-on-sensor scheme is used to minimize both the distance between strips and amplifier (thus reducing the electronic noise) as well as the overall material budget. This report gives an overview on the status of the Belle II SVD and its components, including sensors, front-end detector ladders, mechanics, cooling and the readout electronics.

  10. The silicon vertex detector of the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, T. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technology Guwahati, Assam 781039 (India); Bilka, T. [Faculty of Mathematics and Physics, Charles University, 121 16 Prague (Czech Republic); Bosi, F. [INFN Sezione di Pisa, I-56127 Pisa (Italy); Bosisio, L. [Dipartimento di Fisica, Universitá di Trieste, I-34127 Trieste (Italy); INFN Sezione di Trieste, I-34127 Trieste (Italy); Bozek, A. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); and others

    2016-07-11

    The silicon vertex detector of the Belle II experiment, structured in a lantern shape, consists of four layers of ladders, fabricated from two to five silicon sensors. The APV25 readout ASIC chips are mounted on one side of the ladder to minimize the signal path for reducing the capacitive noise; signals from the sensor backside are transmitted to the chip by bent flexible fan-out circuits. The ladder is assembled using several dedicated jigs. Sensor motion on the jig is minimized by vacuum chucking. The gluing procedure provides such a rigid foundation that later leads to the desired wire bonding performance. The full ladder with electrically functional sensors is consistently completed with a fully developed assembly procedure, and its sensor offsets from the design values are found to be less than 200 μm. The potential functionality of the ladder is also demonstrated by the radioactive source test.

  11. The CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, S.; Carter, H.; Flaugher, B. [and others

    1993-09-01

    A silicon strip vertex detector was designed, constructed and commissioned at the CDF experiment at the Tevatron collider at Fermilab. The mechanical design of the detector, its cooling and monitoring are presented. The front end electronics employing a custom VLSI chip, the readout electronics and various components of the SVX system are described. The system performance and the experience with the operation of the detector in the radiation environment are discussed. The device has been taking colliding beams data since May of 1992, performing at its best design specifications and enhancing the physics program of CDF.

  12. Phosphorous and aluminum gettering in Silicon-Film{trademark} Product II material

    Energy Technology Data Exchange (ETDEWEB)

    Cotter, J.E.; Barnett, A.M.; Hall, R.B. [AstroPower, Inc., Newark, DE (United States)] [and others

    1995-08-01

    Gettering processes are being developed for the Silicon-Film{trademark} Product II solar cell structure. These processes have been developed specifically for films of silicon grown on dissimilar substrates with barrier layers. Gettering with both phosphorous- and aluminum-based processing sequences has resulted in enhancement of minority carrier diffusion length. Long diffusion lengths have allowed the characterization of light trapping in thin films of silicon grown on barrier-coated substrates.

  13. 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).

  14. 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.

  15. The CDF Run IIb Silicon Detector

    Energy Technology Data Exchange (ETDEWEB)

    M. Aoki; N. Bacchetta; S. Behari et al.

    2004-02-25

    Fermilab plans to deliver 5-15 fb{sup -1} of integrated luminosity to the CDF and D0 experiments. The current inner silicon detectors at CDF (SVXIIa and L00) will not tolerate the radiation dose associated with high luminosity running and will need to be replaced. A new readout chip (SVX4) has been designed in radiation-hard 0.25 {micro}m CMOS technology. Single sided sensors are arranged in a compact structure, called a stave, with integrated readout and cooling systems. This paper describes the general design of the Run IIb system, testing results of prototype electrical components (staves), and prototype silicon sensor performance before and after irradiation.

  16. Chip PCR. II. Investigation of different PCR amplification systems in microbabricated silicon-glass chips.

    Science.gov (United States)

    Cheng, J; Shoffner, M A; Hvichia, G E; Kricka, L J; Wilding, P

    1996-01-01

    We examined PCR in silicon dioxide-coated silicon-glass chips (12 microl in volume with a surface to volume ratio of approximately 17.5 mm(2)/microl) using two PCR reagent systems: (i) the conventional reagent system using Taq DNA polymerase; (ii) the hot-start reagent system based on a mixture of TaqStart antibody and Taq DNA polymerase. Quantitative results obtained from capillary electrophoresis for the expected amplification products showed that amplification in microchips was reproducible (between batch coefficient of variation 7.71%) and provided excellent yields. We also used the chip for PCR directly from isolated intact human lymphocytes. The amplification results were comparable with those obtained using extracted human genomic DNA. This investigation is fundamental to the integration of sample preparation, polynucleotide amplification and amplicate detection on a microchip. PMID:8628666

  17. Construction of the new silicon microstrips tracker for the Phase-II ATLAS detector

    CERN Document Server

    Liang, Zhijun; The ATLAS collaboration

    2018-01-01

    The inner detector of the present ATLAS detector has been designed and developed to function in the environment of the present Large Hadron Collider (LHC). At the next-generation tracking detector proposed for the High Luminosity LHC (HL-LHC), the so-called ATLAS Phase-II Upgrade, the particle densities and radiation levels will be higher by as much as a factor of ten. The new detectors must be faster, they need to be more highly segmented, and covering more area. They also need to be more resistant to radiation, and they require much greater power delivery to the front-end systems. For those reasons, the inner tracker of the ATLAS detector must be redesigned and rebuilt completely. The design of the ATLAS Upgrade inner tracker (ITk) has already been defined. It consists of several layers of silicon particle detectors. The innermost layers will be composed of silicon pixel sensors, and the outer layers will consist of silicon microstrip sensors. This paper will focus on the latest research and development act...

  18. Characterization of thin irradiated epitaxial silicon sensors for the CMS phase II pixel 2 upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Centis Vignali, Matteo; Garutti, Erika; Junkes, Alexandra; Steinbrueck, Georg [Institut fuer Experimentalphysik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Eckstein, Doris; Eichhorn, Thomas [Deutsches Elektronen Synchrotron, DESY, Notkestrasse 85, 22607 Hamburg (Germany)

    2015-07-01

    The high-luminosity upgrade of the Large Hadron Collider foreseen around 2023 resulted in the decision to replace the entire tracking system of the CMS experiment. The new pixel detector will be exposed to severe radiation corresponding to 1 MeV neutron equivalent fluence up to φ{sub eq} ∼ 10{sup 16} cm{sup -2} and ionizing dose of ∼ 5 MGy after 3000 fb{sup -1}. Thin planar silicon sensors are good candidates to build the pixel detector since the degradation of the signal is less severe than for thicker devices. A study has been carried out in order to characterize highly irradiated planar epitaxial silicon sensors with an active thickness of 100 μm, in addition other silicon materials with a thickness of 200 μm have been studied. The investigation includes pad diodes and strip detectors irradiated up to a fluence of φ{sub eq} = 1.3 x 10{sup 16} cm{sup -2}. The diodes have been characterized using laboratory measurements, while measurements have been carried out at the DESY II test beam facility to characterize the charge collection of the strip detectors. In this talk, the results obtained for p-bulk sensors are shown.

  19. A bonding study toward the quality assurance of Belle-II silicon vertex detector modules

    Energy Technology Data Exchange (ETDEWEB)

    Kang, K.H.; Jeon, H.B. [RSRI, Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Park, H., E-mail: sunshine@knu.ac.kr [RSRI, Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Uozumi, S. [RSRI, Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, T. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S. [Dipartimento di Fisica, Universitá di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technology Guwahati, Assam 781039 (India); and others

    2016-09-21

    A silicon vertex detector (SVD) for the Belle-II experiment comprises four layers of double-sided silicon strip detectors (DSSDs), assembled in a ladder-like structure. Each ladder module of the outermost SVD layer has four rectangular and one trapezoidal DSSDs supported by two carbon-fiber ribs. In order to achieve a good signal-to-noise ratio and minimize material budget, a novel chip-on-sensor “Origami” method has been employed for the three rectangular sensors that are sandwiched between the backward rectangular and forward (slanted) trapezoidal sensors. This paper describes the bonding procedures developed for making electrical connections between sensors and signal fan-out flex circuits (i.e., pitch adapters), and between pitch adapters and readout chips as well as the results in terms of the achieved bonding quality and pull force. - Highlights: • Gluing and wire binding for Belle-II SVD are studied. • Gluing robot and Origami module are used. • QA are satisfied in terms of the achieved bonding throughput and the pull force. • Result will be applied for L6 ladder assembly.

  20. Operational Experience, Improvements, and Performance of the CDF Run II Silicon Vertex Detector

    CERN Document Server

    Aaltonen, T; Boveia, A.; Brau, B.; Bolla, G; Bortoletto, D; Calancha, C; Carron, S.; Cihangir, S.; Corbo, M.; Clark, D.; Di Ruzza, B.; Eusebi, R.; Fernandez, J.P.; Freeman, J.C.; Garcia, J.E.; Garcia-Sciveres, M.; Gonzalez, O.; Grinstein, S.; Hartz, M.; Herndon, M.; Hill, C.; Hocker, A.; Husemann, U.; Incandela, J.; Issever, C.; Jindariani, S.; Junk, T.R.; Knoepfel, K.; Lewis, J.D.; Martinez-Ballarin, R.; Mathis, M.; Mattson, M.; Merkel, P; Mondragon, M.N.; Moore, R.; Mumford, J.R.; Nahn, S.; Nielsen, J.; Nelson, T.K.; Pavlicek, V.; Pursley, J.; Redondo, I.; Roser, R.; Schultz, K.; Spalding, J.; Stancari, M.; Stanitzki, M.; Stuart, D.; Sukhanov, A.; Tesarek, R.; Treptow, K.; Wallny, R.; Worm, S.

    2013-01-01

    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, an...

  1. Testbeam evaluation of silicon strip modules for ATLAS Phase - II Strip Tracker Upgrade

    CERN Document Server

    Blue, Andrew; The ATLAS collaboration; Ai, Xiaocong; Allport, Phillip; Arling, Jan-Hendrik; Atkin, Ryan Justin; Bruni, Lucrezia Stella; Carli, Ina; Casse, Gianluigi; Chen, Liejian; Chisholm, Andrew; Cormier, Kyle James Read; Cunningham, William Reilly; Dervan, Paul; Diez Cornell, Sergio; Dolezal, Zdenek; Dopke, Jens; Dreyer, Etienne; Dreyling-Eschweiler, Jan Linus Roderik; Escobar, Carlos; Fabiani, Veronica; Fadeyev, Vitaliy; Fernandez Tejero, Javier; Fleta Corral, Maria Celeste; Gallop, Bruce; Garcia-Argos, Carlos; Greenall, Ashley; Gregor, Ingrid-Maria; Greig, Graham George; Guescini, Francesco; Hara, Kazuhiko; Hauser, Marc Manuel; Huang, Yanping; Hunter, Robert Francis Holub; Keller, John; Klein, Christoph; Kodys, Peter; Koffas, Thomas; Kotek, Zdenek; Kroll, Jiri; Kuehn, Susanne; Lee, Steven Juhyung; Liu, Yi; Lohwasser, Kristin; Meszarosova, Lucia; Mikestikova, Marcela; Mi\\~nano Moya, Mercedes; Mori, Riccardo; Moser, Brian; Nikolopoulos, Konstantinos; Peschke, Richard; Pezzullo, Giuseppe; Phillips, Peter William; Poley, Anne-luise; Queitsch-Maitland, Michaela; Ravotti, Federico; Rodriguez Rodriguez, Daniel

    2018-01-01

    The planned HL-LHC (High Luminosity LHC) is being designed to maximise the physics potential of the LHC with 10 years of operation at instantaneous luminosities of \\mbox{$7.5\\times10^{34}\\;\\mathrm{cm}^{-2}\\mathrm{s}^{-1}$}. A consequence of this increased luminosity is the expected radiation damage requiring the tracking detectors to withstand hadron equivalences to over $1x10^{15}$ 1 MeV neutron equivalent per $cm^{2}$ in the ATLAS Strips system. The silicon strip tracker exploits the concept of modularity. Fast readout electronics, deploying 130nm CMOS front-end electronics are glued on top of a silicon sensor to make a module. The radiation hard n-in-p micro-strip sensors used have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics. A series of tests were performed at the DESY-II test beam facility to investigate the detailed performance of a strip module with both 2.5cm and 5cm length strips before irradiation. The DURANTA telescope was used to obtain a pointing...

  2. Characterization of irradiated thin silicon sensors for the CMS phase II pixel upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Centis Vignali, Matteo; Garutti, Erika; Junkes, Alexandra; Steinbrueck, Georg [Institut fuer Experimentalphysik, Universitaet Hamburg (Germany); Eckstein, Doris; Eichhorn, Thomas [Deutsches Elektronen Synchrotron (DESY) (Germany)

    2016-07-01

    The high-luminosity upgrade of the Large Hadron Collider, foreseen for 2025, necessitates the replacement of the tracker of the CMS experiment. The innermost layer of the new pixel detector will be exposed to severe radiation corresponding to a 1 MeV neutron equivalent fluence up to Φ{sub eq} = 2 . 10{sup 16} cm{sup -2} and an ionizing dose of ∼ 10 MGy after an integrated luminosity of 3000 fb{sup -1}. Silicon crystals grown with different methods and sensor designs are under investigation in order to optimize the sensors for such high fluences. Thin planar silicon sensors are good candidates to achieve this goal, since the degradation of the signal produced by traversing particles is less severe than for thicker devices. Epitaxial pad diodes and strip sensors irradiated up to fluences of Φ{sub eq} = 1.3 . 10{sup 16} cm{sup -2} have been characterized in laboratory measurements and beam tests at the DESY II facility. The active thickness of the strip sensors and pad diodes is 100 μm. In addition, strip sensors produced using other growth techniques with a thickness of 200 μm have been studied. In this talk, the results obtained for p-bulk sensors are shown.

  3. Simultaneous alignment and Lorentz angle calibration in the CMS silicon tracker using Millepede II

    Energy Technology Data Exchange (ETDEWEB)

    Bartosik, Nazar; Behr, Joerg; Flucke, Gero; Hellwig, Gregor; Kleinwort, Claus; Mankel, Rainer [DESY, Hamburg (Germany)

    2013-07-01

    An accurate determination of the positions and orientations of 25 684 sensors of the CMS silicon tracker is crucial for the physics performance of the whole experiment. This is achieved by track-based alignment using the global fit approach of the Millepede II program. About 200 000 parameters are determined simultaneously, including parameters describing sensor curvatures. The alignment framework has now been extended to treat position sensitive calibration parameters. Of special interest is the Lorentz angle which affects hit positions due to the drift of signal electrons in the magnetic field. The Lorentz angle and its time dependence, induced e.g. by the increasing accumulated radiation dose, have been determined for 2012, making use of data taken with magnetic field switched off.

  4. Simultaneous alignment and Lorentz angle calibration in the CMS silicon tracker using Millepede II

    CERN Document Server

    Bartosik, Nazar

    2013-01-01

    The CMS silicon tracker consists of 25 684 sensors that provide measurements of trajectories of charged particles that are used by almost every physics analysis at CMS. In order to achieve high measurement precision, the positions and orientations of all sensors have to be determined very accurately. This is achieved by track-based alignment using the global fit approach of the Millepede II program. This approach is capable of determining about 200 000 parameters simultaneously.The alignment precision reached such a high level that even small calibration inaccuracies are noticeable. Therefore the alignment framework has been extended to treat position sensitive calibration parameters. Of special interest is the Lorentz angle which affects the hit positions due to the drift of the signal electrons in the magnetic field. We present the results from measurements of the Lorentz angle and its time dependence during full 2012 data taking period as well as general description of the alignment and calibration procedu...

  5. The Donor-Stabilized Silylene Bis[N,N´-diisopropylbenzamidinato(–)]silicon(ii): Synthesis, Electronic Structure, and Reactivity

    NARCIS (Netherlands)

    Junold, K.; Nutz, M.; Baus, J.A.; Burschka, C.; Fonseca Guerra, C.; Bickelhaupt, F.M.; Tacke, R.

    2014-01-01

    A convenient and robust synthesis of bis[N,N′- diisopropylbenzamidinato(-)]silicon(II) (1), a donor-stabilized silylene, has been developed (35 g scale). To get further information about the reactivity profile of 1, a series of oxidative addition reactions were studied. Treatment of 1 with PhSe-SePh

  6. MEG II drift chamber characterization with the silicon based cosmic ray tracker at INFN Pisa

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M., E-mail: marco.venturini@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Baldini, A.M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Baracchini, E. [ICEPP, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Cei, F.; D' Onofrio, A. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, dell' Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dussoni, S.; Galli, L.; Grassi, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Nicolò, D. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, dell' Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Signorelli, G. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2016-07-11

    High energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to provide an external track reference. It consists of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15–30 μm. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He–isobutane 85–15%. The ionization density in this gas mixture is about 13 clusters/cm and this results in a non-negligible bias of the impact parameters for tracks crossing the cell close to the anode wire. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterization of a MEG II drift chamber prototype.

  7. MEG II drift chamber characterization with the silicon based cosmic ray tracker at INFN Pisa

    Science.gov (United States)

    Venturini, M.; Baldini, A. M.; Baracchini, E.; Cei, F.; D`Onofrio, A.; Dussoni, S.; Galli, L.; Grassi, M.; Nicolò, D.; Signorelli, G.

    2016-07-01

    High energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to provide an external track reference. It consists of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15-30 μm. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He-isobutane 85-15%. The ionization density in this gas mixture is about 13 clusters/cm and this results in a non-negligible bias of the impact parameters for tracks crossing the cell close to the anode wire. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterization of a MEG II drift chamber prototype.

  8. Silicon strip prototypes for the Phase-II upgrade of the ATLAS tracker for the HL-LHC

    CERN Document Server

    INSPIRE-00474514

    2013-01-01

    This paper describes the integration structures for the silicon strips tracker of the ATLAS detector proposed for the Phase-II upgrade of the Large Hadron Collider (LHC), also referred to as High Luminosity LHC (HL-LHC). In this proposed detector Silicon strip sensors are arranged in highly modular structures, called `staves' and `petals'. This paper presents performance results from the latest prototype stave built at Berkeley. This new, double-sided prototype is composed of a specialized core structure, in which a shield-less bus tape is embedded in between carbon fiber lay-ups. A detailed description of the prototype and its electrical performance are discussed in detail.

  9. Silicon Sensor Prototypes for the Phase II Upgrade of the CMS Tracker

    CERN Document Server

    AUTHOR|(CDS)2068606

    2015-01-01

    The High-Luminosity LHC (HL-LHC) has been identified as the highest priority program in High Energy Physics in the mid-term future. It will provide the experiments an additional integrated luminosity of about 2500 fb$^{−1}$ over 10 years of operation, starting in 2025. In order to meet the experimental challenges of unprecedented p–p luminosity, especially in terms of radiation levels and occupancy, the CMS collaboration will need to replace its entire strip tracker by a new one. In this paper the baseline layout option for this new Phase-II tracker is shown, together with two variants using a tilted barrel geometry or larger modules from 8-inch silicon wafers. Moreover, the two module concepts are discussed, which consist either of two strip sensors (2S) or of one strip and one pixel sensor (PS). These two designs allow $p_{T}$ discrimination at module level enabling the tracker to contribute to the L1 trigger decision. The paper presents testing results of the macro-pixel-light sensor for the PS module...

  10. Commissioning of the control and data acquisition electronics for the CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, S.M.; Turner, K.J.; Nelson, C.A.; Shaw, T.M.; Wesson, T.R. [Fermi National Accelerator Lab., Batavia, IL (United States); Bailey, M.W.; Kruse, M.C. [Purdue Univ., Lafayette, IN (United States); Castro, A. [Padua Univ. (Italy)

    1991-11-01

    The SVX data acquisition system includes three components: a Fastbus Sequencer, an SVX Rabbit Crate Controller and a Digitizer. These modules are integrated into the CDF DAQ system and operate the readout chips. The results of the extensive functional tests of the SVX modules are reported. We discuss the stability of the Sequencers, systematic differences between them and methods of synchronization with the Tevatron beam crossings. The Digitizer ADC calibration procedure run on the microsequencer is described. The microsequencer code used for data taking and SVX chip calibration modes is described. Measurements of the SVX data scan time are discussed.

  11. Silicon strip tracking detector development and prototyping for the Phase-II upgrade of the ATLAS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S., E-mail: susanne.kuehn@cern.ch

    2016-07-11

    In about ten years from now, the Phase-II upgrade of the LHC will be carried out. Due to increased luminosity, a severe radiation dose and high particle rates will occur for the experiments. In consequence, several detector components will have to be upgraded. In the ATLAS experiment, the current inner detector will be replaced by an all-silicon tracking detector with the goal of at least delivering the present detector performance also in the harsh Phase-II LHC conditions. This report presents the current planning and results from first prototype measurements of the upgrade silicon strip tracking detector. - Highlights: • Upgrade of current inner detector of the ATLAS experiment foreseen for High-Luminosity-LHC. • Silicon strip tracker for the upgrade has a modular design, single units are built and tested standalone before assembly in larger structures. • The prototyping is well advanced and approaching maturity. • Several integrated objects have been built, e.g. 70 barrel and 40 endcap prototype modules show low noise test results. • Many additional R & D tasks are ongoing and the collaboration is planning for preparing a technical design report before the end of 2016.

  12. INVESTIGATION OF ADSORBABILITY OF SILICON DIOXIDE FROM RICE HULL AS REGARDS COPPER (II) AND MANGANESE (II) IONS

    OpenAIRE

    Холомейдик (Kholomeydik), Анна (Anna) Николаевна (Nikolaevna); Николенко (Nikolenko), Юрий (Jurij) Михайлович (Mihajlovich); Земнухова (Zemnuhova), Людмила (Ljudmila) Алексеевна (Alekseevna); Устинов (Ustinov), Алекандр (Alekandr) Юрьевич (Jur'evich); Майоров (Mayorov), Виталий (Vitalij) Юрьевич (Yur'evich); Полякова (Polyakova), Наталья (Natal'ja) Владимировна (Vladimirovna)

    2015-01-01

    The samples silicone dioxide containing 95−99,9% of the basic substance depending on conditions of the raw materials preparation and the temperature of treatment were obtained from rice hull by the oxidation burring method. Their phase composition and morphology were studied. The samples have amorphous and crystal state. Their specific surface and pore size distribution were determined by nitrogen adsorption. The specific surface value varied in the range of 6−230 m2/g and the pore diameters ...

  13. The effective determination of Cd(ii) and Pb(ii) simultaneously based on an aluminum silicon carbide-reduced graphene oxide nanocomposite electrode.

    Science.gov (United States)

    Wu, Yale; Yang, Tao; Chou, Kuo-Chih; Chen, Junhong; Su, Lei; Hou, Xinmei

    2017-07-24

    A platform for the simultaneous determination of Cd(ii) and Pb(ii) in aqueous solution has been applied based on an aluminum silicon carbide-reduced graphene oxide nanocomposite (Al4SiC4-RGO) modified bismuth film glassy carbon electrode (GCE) using square wave anodic stripping voltammetry (SWASV) for the first time. The Al4SiC4-RGO nanocomposite electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with the Al4SiC4 modified GCE and bare GCE, the electrochemical performance of the Al4SiC4-RGO nanocomposite electrode is obviously enhanced resulting from the synergistic effects of Al4SiC4, RGO and bismuth film. The chemical and electrochemical parameters that exert an influence on the deposition and stripping of metal ions, such as supporting electrolytes, pH values, concentrations of Bi3+, deposition potentials and deposition times, were carefully studied. Under optimal conditions, a linear relationship exists between the currents and the concentrations of Cd(ii) and Pb(ii) in the range of 50 to 2700 μg L-1. The limits of detection (S/N = 3) are estimated to be 1.30 μg L-1 for Pb(ii) and 2.15 μg L-1 for Cd(ii). Compared with the related work reported in the literature, the analytical performance in this work has a lower determination limit and a wider detection linear range. In addition, this electrode also exhibits good stability and reproducibility. These results imply that the Al4SiC4-RGO nanocomposite might be a promising candidate for practical applications in the electrochemical detection of metal ions.

  14. Elemental abundance studies of CP stars. II. The silicon stars HD 133029 and HD 192913

    CERN Document Server

    López-García, Z

    1999-01-01

    For pt.1 see ibid., vol.107, no.2, p.353-63 (1994). Fine analyses of the silicon stars HD 133029 and HD 192913 are presented using ATLAS9 model atmospheres whose predictions fit the optical region spectrophotometry and H gamma profiles and have the same bulk metallicity as the deduced abundances. Both are very He poor stars. The light elements are mostly solar except for silicon, and all the heavier elements, except nickel in HD 133029 which is solar, are greatly overabundant. The iron peak elements are typically 10 times overabundant. SrYZr are of order of 100 times solar. The rare earths are 1000 or more times overabundant. Table 4 is is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html. (50 refs).

  15. Characterisation of irradiated thin silicon sensors for the CMS phase II pixel upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Bergauer, T.; Brondolin, E. [Institut fuer Hochenergiephysik, Vienna (Austria); and others

    2017-08-15

    The high luminosity upgrade of the Large Hadron Collider, foreseen for 2026, necessitates the replacement of the CMS experiment's silicon tracker. The innermost layer of the new pixel detector will be exposed to severe radiation, corresponding to a 1 MeV neutron equivalent fluence of up to Φ{sub eq} = 2 x 10{sup 16} cm{sup -2}, and an ionising dose of ∼5 MGy after an integrated luminosity of 3000 fb{sup -1}. Thin, planar silicon sensors are good candidates for this application, since the degradation of the signal produced by traversing particles is less severe than for thicker devices. In this paper, the results obtained from the characterisation of 100 and 200 μm thick p-bulk pad diodes and strip sensors irradiated up to fluences of Φ{sub eq} = 1.3 x 10{sup 16} cm{sup -2} are shown. (orig.)

  16. Development of a 3D printable maxillofacial silicone: Part II. Optimization of moderator and thixotropic agent.

    Science.gov (United States)

    Jindal, Swati K; Sherriff, Martyn; Waters, Mark G; Smay, James E; Coward, Trevor J

    2018-02-01

    Conventionally, maxillofacial prostheses are fabricated by hand carving the missing anatomic defect in wax and creating a mold into which pigmented silicone elastomer is placed. Digital technologies such as computer numerical control milling and 3-dimensional (3D) printing have been used to prepare molds, directly or indirectly, into which a biocompatible pigmented silicone elastomer can be placed. The purpose of this in vitro study was to develop a silicone elastomer that could be 3D printed directly without a mold to create facial or body prostheses by varying its composition. The room temperature vulcanizing silicone composition was divided into 2 components which were mixed 1:1 to initiate polymerization in the printer before printing began. Different types of moderators and thixotropic agents were used, and the base composition was varied to obtain 11 formulations. The specimens were printed and polymerized from these formulations and tested for tear and tensile strength and hardness. Ten readings of the specimens were recorded for tear and tensile strength and 6 for hardness. Results were analyzed using ANOVA (α=.05). Visual assessment of uncured printed specimens was undertaken for 5 formulations to assess any differences in their ability to hold their shape after printing. The tear and tensile strength of the 11 formulations with varying moderators, thixotropic agents, and base compositions were statistically similar to each other (P>.05). Five of 11 formulations were chosen for the visual assessment as they had sufficient thixotropic agent to avoid slumping while printing. The specimens showed varied slumping behavior until they polymerized. The filler content was increased in the selected formulation, and the tear and tensile strength of the formulation was increased to 6.138 kNm -1 and 3.836 MPa; these increases were comparable to those of commercial silicones currently used for the fabrication of facial prostheses. The optimum combination of

  17. Test-beam evaluation of heavily irradiated silicon strip modules for ATLAS Phase-II Strip Tracker Upgrade

    CERN Document Server

    Blue, Andrew; The ATLAS collaboration

    2018-01-01

    The planned HL-LHC (High Luminosity LHC) is being designed to maximise the physics potential of the LHC with 10 years of operation at instantaneous luminosities of 7.5x1034cm−2s−1. A consequence of this increased luminosity is the expected radiation damage requiring the tracking detectors to withstand hadron equivalences to over 1x1015 1 MeV neutron equivalent per cm2 in the ATLAS Strips system. The silicon strip tracker exploits the concept of modularity. Fast readout electronics, deploying 130nm CMOS front-end electronics are glued on top of a silicon sensor to make a module. The radiation hard n-in-p micro-strip sensors used have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics. A series of tests were performed at the DESY-II and CERN SPS test beam facilities to investigate the detailed performance of a strip module with both 2.5cm and 5cm length strips before and after irradiation with 8x1014neqcm−2 protons and a total ionising dose of 37.2MRad. The DURA...

  18. Towards Gotthard-II: development of a silicon microstrip detector for the European X-ray Free-Electron Laser

    Science.gov (United States)

    Zhang, J.; Andrä, M.; Barten, R.; Bergamaschi, A.; Brückner, M.; Dinapoli, R.; Fröjdh, E.; Greiffenberg, D.; Lopez-Cuenca, C.; Mezza, D.; Mozzanica, A.; Ramilli, M.; Redford, S.; Ruat, M.; Ruder, C.; Schmitt, B.; Shi, X.; Thattil, D.; Tinti, G.; Turcato, M.; Vetter, S.

    2018-01-01

    Gotthard-II is a 1-D microstrip detector specifically developed for the European X-ray Free-Electron Laser. It will not only be used in energy dispersive experiments but also as a beam diagnostic tool with additional logic to generate veto signals for the other 2-D detectors. Gotthard-II makes use of a silicon microstrip sensor with a pitch of either 50 μm or 25 μm and with 1280 or 2560 channels wire-bonded to adaptive gain switching readout chips. Built-in analog-to-digital converters and digital memories will be implemented in the readout chip for a continuous conversion and storage of frames for all bunches in the bunch train. The performance of analogue front-end prototypes of Gotthard has been investigated in this work. The results in terms of noise, conversion gain, dynamic range, obtained by means of infrared laser and X-rays, will be shown. In particular, the effects of the strip-to-strip coupling are studied in detail and it is found that the reduction of the coupling effects is one of the key factors for the development of the analogue front-end of Gotthard-II.

  19. Bis[N,N'-diisopropylbenzamidinato(-)]silicon(II): Lewis acid/base reactions with triorganylboranes.

    Science.gov (United States)

    Junold, Konstantin; Baus, Johannes A; Burschka, Christian; Fonseca Guerra, Célia; Bickelhaupt, F Matthias; Tacke, Reinhold

    2014-09-22

    Reaction of the donor-stabilized silylene 1 (which is three-coordinate in the solid state and four-coordinate in solution) with BEt3 and BPh3 leads to the formation of the Lewis acid/base complexes 2 and 3, respectively, which are the first five-coordinate silicon compounds with an SiB bond. These compounds were structurally characterized by crystal structure analyses and by multinuclear NMR spectroscopic studies in the solid state and in solution. Additionally, the bonding situation in 2 and 3 was analyzed by quantum chemical studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A Silicon Strip Detector for the Phase II High Luminosity Upgrade of the ATLAS Detector at the Large Hadron Collider

    CERN Document Server

    INSPIRE-00425747; McMahon, Stephen J

    2015-01-01

    ATLAS is a particle physics experiment at the Large Hadron Collider (LHC) that detects proton-proton collisions at a centre of mass energy of 14 TeV. The Semiconductor Tracker is part of the Inner Detector, implemented using silicon microstrip detectors with binary read-out, providing momentum measurement of charged particles with excellent resolution. The operation of the LHC and the ATLAS experiment started in 2010, with ten years of operation expected until major upgrades are needed in the accelerator and the experiments. The ATLAS tracker will need to be completely replaced due to the radiation damage and occupancy of some detector elements and the data links at high luminosities. These upgrades after the first ten years of operation are named the Phase-II Upgrade and involve a re-design of the LHC, resulting in the High Luminosity Large Hadron Collider (HL-LHC). This thesis presents the work carried out in the testing of the ATLAS Phase-II Upgrade electronic systems in the future strips tracker a...

  1. Steric stabilization of nonaqueous silicon slips. I - Control of particle agglomeration and packing. II - Pressure casting of powder compacts

    Science.gov (United States)

    Kerkar, Awdhoot V.; Henderson, Robert J. M.; Feke, Donald L.

    1990-01-01

    The application of steric stabilization to control particle agglomeration and packing of silicon powder in benzene and trichloroethylene is reported. The results provide useful guidelines for controlling unfavorable particle-particle interactions during nonaqueous processing of silicon-based ceramic materials. The application of steric stabilization to the control and improvement of green processing of nonaqueous silicon slips in pressure consolidation is also demonstrated.

  2. Reactions of the donor-stabilized silylene bis[N,N'-diisopropyl-benzamidinato(-)]silicon(II) with Brønsted acids.

    Science.gov (United States)

    Junold, Konstantin; Sinner, Katharina; Baus, Johannes A; Burschka, Christian; Fonseca Guerra, Célia; Bickelhaupt, F Matthias; Tacke, Reinhold

    2014-12-08

    Reaction of the donor-stabilized silylene 1 (which is three-coordinate in the solid state and four-coordinate in solution) with [HMCp(CO)3 ] (M=Mo, W; Cp=cyclopentadienyl) leads to the cationic five-coordinate silicon(IV) complexes 2 and 3, respectively, and reaction of 1 with CH3 COOH yields the neutral six-coordinate silicon(IV) complex 4. Compounds 2-4 were structurally characterized by crystal structure analyses and multinuclear NMR spectroscopic studies in the solid state and in solution. The formation of 2-4 can be formally described in terms of a Brønsted acid/base reaction, coupled with a redox process (Si(II) →Si(IV) , H(+) →H(-) ). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Reduction in driveline infection rates: Results from the HeartMate II Multicenter Driveline Silicone Skin Interface (SSI) Registry.

    Science.gov (United States)

    Dean, David; Kallel, Faouzi; Ewald, Gregory A; Tatooles, Antony; Sheridan, Brett C; Brewer, Robert J; Caldeira, Christian; Farrar, David J; Akhter, Shahab A

    2015-06-01

    During left ventricular assist device implantation, a surgical tunneling technique to keep the entire driveline (DL) velour portion in the subcutaneous tunnel, resulting in a silicone-skin interface (SSI) at the exit site, has been adopted by many centers. To assess long-term freedom from DL infection associated with this technique, a multicenter SSI registry was initiated. It was hypothesized that the modified tunneling technique is associated with at least 50% reduction in DL infection at 1 year post-implant compared with the velour-to-skin method used in the HeartMate II (HMII) Destination Therapy (DT) trial. SSI is a retrospective and prospective registry of patients who have received the HMII device. Results are reported from the retrospective cohort, which consists of 200 patients who were implanted during the period 2009-2012 with the SSI tunneling method and on HMII support for at least 10 months at the time of enrollment. The prevalence and incidence of DL infection after left ventricular assist device implantation in the SSI retrospective cohort were determined and compared with a control group of 201 patients also on HMII support for at least 10 months from the HMII DT clinical trial who were implanted during the period 2007-2009 using the traditional method in which a small section of the velour portion of the DL was externalized. The 1-year and 2-year prevalence rates of DL infection were 9% and 19% in the SSI patient group compared with 23% and 35% in the control group (hazard ratio 0.49, 95% confidence interval 0.33-0.73, p < 0.001). The event-per-patient year was 0.11 and 0.22 for the SSI and control groups, respectively (p < 0.001). Based on a multivariate analysis, age and DL exit side were the only independent variables associated with DL infection. Effects of management changes over the eras were not studied and could have contributed to the findings. These results suggest that leaving the entire DL velour portion below the skin is associated

  4. Mass test of AdvanSiD model ASD-NUV3S-P SiliconPMs for the Pixel Timing Counter of the MEG II experiment

    Science.gov (United States)

    Rossella, M.; Bariani, S.; Barnaba, O.; Cattaneo, P. W.; Cervi, T.; Menegolli, A.; Nardò, R.; Prata, M. C.; Romano, E.; Scagliotti, C.; Simonetta, M.; Vercellati, F.

    2017-02-01

    The MEG II Timing Counter will measure the positron time of arrival with a resolution of 30 ps relying on two arrays of scintillator pixels read out by 6144 Silicon Photomultipliers (SiPMs) from AdvanSiD. They must be characterized, measuring their breakdown voltage, to assure that the gains of the SiPMs of each pixel are as uniform as possible, to maximize the pixel resolution. To do this an automatic test system that can measure sequentially the parameters of 32 devices has been developed.

  5. 2 μm wavelength range InP-based type-II quantum well photodiodes heterogeneously integrated on silicon photonic integrated circuits.

    Science.gov (United States)

    Wang, Ruijun; Sprengel, Stephan; Muneeb, Muhammad; Boehm, Gerhard; Baets, Roel; Amann, Markus-Christian; Roelkens, Gunther

    2015-10-05

    The heterogeneous integration of InP-based type-II quantum well photodiodes on silicon photonic integrated circuits for the 2 µm wavelength range is presented. A responsivity of 1.2 A/W at a wavelength of 2.32 µm and 0.6 A/W at 2.4 µm wavelength is demonstrated. The photodiodes have a dark current of 12 nA at -0.5 V at room temperature. The absorbing active region of the integrated photodiodes consists of six periods of a "W"-shaped quantum well, also allowing for laser integration on the same platform.

  6. Prototyping of hybrids and modules for the forward silicon strip tracking detector for the ATLAS Phase-II upgrade

    Science.gov (United States)

    Kuehn, S.; Benítez, V.; Fernández-Tejero, J.; Fleta, C.; Lozano, M.; Ullán, M.; Lacker, H.; Rehnisch, L.; Sperlich, D.; Ariza, D.; Bloch, I.; Díez, S.; Gregor, I.; Keller, J.; Lohwasser, K.; Poley, L.; Prahl, V.; Zakharchuk, N.; Hauser, M.; Jakobs, K.; Mahboubi, K.; Mori, R.; Parzefall, U.; Bernabéu, J.; Lacasta, C.; Marco-Hernandez, R.; Santoyo, D.; Solaz Contell, C.; Soldevila Serrano, U.; Affolder, T.; Greenall, A.; Gallop, B.; Phillips, P. W.

    2017-05-01

    For the High-Luminosity upgrade of the Large Hadron Collider an increased instantaneous luminosity of up to 7.5 ṡ 1034 cm-2 s-1, leading to a total integrated luminosity of up to 3000 fb-1, is foreseen. The current silicon and transition radiation tracking detectors of the ATLAS experiment will be unable to cope with the increased track densities and radiation levels, and will need to be replaced. The new tracking detector will consist entirely of silicon pixel and strip detectors. In this paper, results on the development and tests of prototype components for the new silicon strip detector in the forward regions (end-caps) of the ATLAS detector are presented. Flex-printed readout boards with fast readout chips, referred to as hybrids, and silicon detector modules are investigated. The modules consist of a hybrid glued onto a silicon strip sensor. The channels on both are connected via wire-bonds for readout and powering. Measurements of important performance parameters and a comparison of two possible readout schemes are presented. In addition, the assembly procedure is described and recommendations for further prototyping are derived.

  7. Alternative glues for the production of ATLAS silicon strip modules for the Phase-II upgrade of the ATLAS Inner Detector

    CERN Document Server

    INSPIRE-00407830; Bloch, Ingo; Edwards, Sam; Friedrich, Conrad; Gregor, Ingrid M.; Jones, T; Lacker, Heiko; Pyatt, Simon; Rehnisch, Laura; Sperlich, Dennis; Wilson, John

    2016-05-24

    The Phase-II upgrade of the ATLAS detector for the High Luminosity Large Hadron Collider (HL-LHC) includes the replacement of the current Inner Detector with an all-silicon tracker consisting of pixel and strip detectors. The current Phase-II detector layout requires the construction of 20,000 strip detector modules consisting of sensor, circuit boards and readout chips, which are connected mechanically using adhesives. The adhesive between readout chips and circuit board is a silver epoxy glue as was used in the current ATLAS SemiConductor Tracker (SCT). This glue has several disadvantages, which motivated the search for an alternative. This paper presents a study concerning the use of six ultra-violet (UV) cure glues and a glue pad for use in the assembly of silicon strip detector modules for the ATLAS upgrade. Trials were carried out to determine the ease of use, the thermal conduction and shear strength, thermal cycling, radiation hardness, corrosion resistance and shear strength tests. These investigatio...

  8. Pressure dependence of in situ boron-doped silicon films prepared by low-pressure chemical vapor deposition. II. Resistivity

    Science.gov (United States)

    Haji, L.; Hamedi, L.; Loisel, B.; Gauneau, M.; Joubert, P.; Sarret, M.

    1989-11-01

    The effects of silane pressure and temperature on the in situ boron incorporation and resistivity of low-pressure chemical vapor deposited polycrystalline silicon films were studied in the ranges of 2.5×10-3-1 Torr and 515-700 °C. By lowering the silane pressure, the boron concentration increases (up to 1×1022 cm-3) and the resistivity decreases down to about 2×10-3 Ω cm without annealing. For high deposition pressure (≥0.1 Torr), the resistivity decreases as the temperature is lowered. In this latter case the secondary-ion mass spectrometry profiles reveal a boron accumulation at the layer-substrate interface, which is always observed independently of the substrate nature.

  9. 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

  10. Prototyping of petalets for the Phase-II Upgrade of the silicon strip tracking detector of the ATLAS Experiment arXiv

    CERN Document Server

    Kuehn, S.; Fernández-Tejero, J.; Fleta, C.; Lozano, M.; Ullán, M.; Lacker, H.; Rehnisch, L.; Sperlich, D.; Ariza, D.; Bloch, I.; Díez, S.; Gregor, I.; Keller, J.; Lohwasser, K.; Poley, L.; Prahl, V.; Zakharchuk, N.; Hauser, M.; Jakobs, K.; Mahboubi, K.; Mori, R.; Parzefall, U.; Bernabéu, J.; Lacasta, C.; Marco-Hernandez, R.; Santoyo, D.; Solaz Contell, C.; Soldevila Serrano, U.; Affolder, T.; Greenall, A.; Gallop, B.; Phillips, P.W.; Cindro, V.

    In the high luminosity era of the Large Hadron Collider, the HL-LHC, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The ITk consists of a silicon pixel and a strip detector and exploits the concept of modularity. Prototyping and testing of various strip detector components has been carried out. This paper presents the developments and results obtained with reduced-size structures equivalent to those foreseen to be used in the forward region of the silicon strip detector. Referred to as petalets, these structures are built around a composite sandwich with embedded cooling pipes and electrical tapes for routing the signals and power. Detector modules built using electronic flex boards and silicon strip sensors are glued on both the front...

  11. Ruthenium catalyst on carbon nanofiber support layers for use in silicon-based structured microreactors, Part II: Catalytic reduction of bromate contaminants in aqueous phase

    NARCIS (Netherlands)

    Thakur, D.B.; Tiggelaar, Roald M.; Weber, Y.; Gardeniers, Johannes G.E.; Lefferts, Leonardus; Seshan, Kulathuiyer

    2011-01-01

    Catalyst layers were synthesized inside a structured channel of silicon based microreactor and used to remove bromate contaminants in water. It is demonstrated that Ru/CNF based catalyst is active for bromate reduction, resulting in turn over frequencies (TOFs) higher than conventional powdered

  12. Measurement of the Inclusive $b$-jet cross section in $p\\bar{p}$ collisions at CDF RunII and Development of silicon microstrip detectors for the ATLAS silicon tracker

    Energy Technology Data Exchange (ETDEWEB)

    D' Onofrio, Monica [Univ. of Geneva (Switzerland)

    2005-01-01

    In the past twenty years, the study of events with bottom quark has led to many important Tevatron results- as the discovery of the top quark- and it will be as well crucial at the LHC for the search of new physics phenomena. This analysis exploits the good tracking capabilities of the detector and relies on b-jet identification made by secondary vertex reconstruction. The study of the Inner Tracker system performance and in particular the Semi conductor Tracker (SCT), can be considered one of the fundamental issues in the construction of the apparatus. The second part of this thesis work reports some of the crucial tests performed during the development of the silicon microstrip detectors composing the SCT.

  13. Characterisation of silicon microstrip detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Poley, Luise [DESY, Hamburg (Germany); Blue, Andrew; Bates, Richard [Glasgow Univ. (United Kingdom). SUPA School of Physics and Astronomy; and others

    2016-03-15

    The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity, totalling 1 x 10{sup 35} cm{sup -2}s{sup -1} after 10 years of operation. A consequence of this increased luminosity is the expected radiation damage at 3000 fb{sup -1}, requiring the tracking detectors to withstand hadron equivalences to over 1 x 10{sup 16} 1 MeV neutrons per cm{sup 2}. With the addition of increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 μm FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 μm thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 μm thick full size radial (Endcap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout chips (ABCN-25). Sub-strip resolution of the 74.5 μm strips was achieved for both detectors. Investigation of the p-stop diffusion layers between strips is shown in detail for the wire bond pad regions. Inter strip charge collection measurements indicate that the effective width of the strip on the silicon sensors is determined by p-stops regions between the strips rather than the strip pitch. The collected signal allowed for the identification of operating thresholds for both devices, making it possible to compare signal response between different versions of silicon strip detector modules.

  14. A first-principles study of carbon-related energy levels in GaN. II. Complexes formed by carbon and hydrogen, silicon or oxygen

    Science.gov (United States)

    Matsubara, Masahiko; Bellotti, Enrico

    2017-05-01

    This work presents an in-depth investigation of the properties of complexes composed of hydrogen, silicon, or oxygen with carbon, which are the major unintentional impurities in undoped GaN. This manuscript is a complement to our previous work on carbon-carbon and carbon-vacancy complexes. We have employed a first-principles method using Heyd-Scuseria-Ernzerhof hybrid functionals within the framework of generalized Kohn-Sham density functional theory. Two H-C, four Si-C, and five O-C complexes in different charge states have been considered. After full geometry relaxations, formation energies, binding energies, and both thermal and optical transition levels were obtained. The calculated energy levels have been systematically compared with the experimentally observed carbon related trap levels. Furthermore, we computed vibrational frequencies for selected defect complexes and defect concentrations were estimated in the low, mid, and high carbon doping scenarios considering two different cases where electrically active defects: (a) only carbon and vacancies and (b) not only carbon and vacancies but also hydrogen, silicon, and oxygen. We confirmed that CN is a dominant acceptor in GaN. In addition to it, a substantial amount of SiGa-CN complex exists in a neutral form. This complex is a likely candidate for the unknown form of carbon observed in undoped n-type GaN.

  15. Using silicon-coated gold nanoparticles to enhance the fluorescence of CdTe quantum dot and improve the sensing ability of mercury (II)

    Science.gov (United States)

    Zhu, Jian; Chang, Hui; Li, Jian-Jun; Li, Xin; Zhao, Jun-Wu

    2018-01-01

    The effect of silicon-coated gold nanoparticles with different gold core diameter and silica shell thickness on the fluorescence emission of CdTe quantum dots (QDs) was investigated. For gold nanoparticles with a diameter of 15 nm, silica coating can only results in fluorescence recover of the bare gold nanoparticle-induced quenching of QDs. However, when the size of gold nanoparticle is increased to 60 nm, fluorescence enhancement of the QDs could be obtained by silica coating. Because of the isolation of the silica shell-reduced quenching effect and local electric field effect, the fluorescence of QDs gets intense firstly and then decreases. The maximum fluorescence enhancement takes place as the silica shell has a thickness of 30 nm. This enhanced fluorescence from silicon-coated gold nanoparticles is demonstrated for sensing of Hg2 +. Under optimal conditions, the enhanced fluorescence intensity decreases linearly with the concentration of Hg2 + ranging from 0 to 200 ng/mL. The limit of detection for Hg2 + is 1.25 ng/mL. Interference test and real samples detection indicate that the influence from other metal ions could be neglected, and the Hg2 + could be specifically detected.

  16. 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.

  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. Characterisation of strip silicon detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam

    Science.gov (United States)

    Poley, L.; Blue, A.; Bates, R.; Bloch, I.; Díez, S.; Fernandez-Tejero, J.; Fleta, C.; Gallop, B.; Greenall, A.; Gregor, I.-M.; Hara, K.; Ikegami, Y.; Lacasta, C.; Lohwasser, K.; Maneuski, D.; Nagorski, S.; Pape, I.; Phillips, P. W.; Sperlich, D.; Sawhney, K.; Soldevila, U.; Ullan, M.; Unno, Y.; Warren, M.

    2016-07-01

    The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity up to 6·1034 cm-2s-1. A consequence of this increased luminosity is the expected radiation damage at 3000 fb-1 after ten years of operation, requiring the tracking detectors to withstand fluences to over 1·1016 1 MeV neq/cm2. In order to cope with the consequent increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 μm FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 μm thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 μm thick full size radial (end-cap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout chips (ABCN-25). A resolution better than the inter strip pitch of the 74.5 μm strips was achieved for both detectors. The effect of the p-stop diffusion layers between strips was investigated in detail for the wire bond pad regions. Inter strip charge collection measurements indicate that the effective width of the strip on the silicon sensors is determined by p-stop regions between the strips rather than the strip pitch.

  19. 76 FR 70966 - Crystalline Silicon Photovoltaic Cells, Whether or Not Assembled Into Modules, From the People's...

    Science.gov (United States)

    2011-11-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE... this case, see ``Countervailing Duty Investigation Initiation Checklist: Certain Crystalline Silicon... Checklist), at Attachment II, Analysis of Industry Support for the Petitions Covering Crystalline Silicon...

  20. Characterisation of strip silicon detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam

    CERN Document Server

    INSPIRE-00407830; Blue, Andrew; Bates, Richard; Bloch, Ingo; Diez, Sergio; Fernandez-Tejero, Javier; Fleta, Celeste; Gallop, Bruce; Greenall, Ashley; Gregor, Ingrid-Maria; Hara, Kazuhiko; Ikegami, Yoichi; Lacasta, Carlos; Lohwasser, Kristin; Maneuski, Dzmitry; Nagorski, Sebastian; Pape, Ian; Phillips, Peter W.; Sperlich, Dennis; Sawhney, Kawal; Soldevila, Urmila; Ullan, Miguel; Unno, Yoshinobu; Warren, Matt

    2016-07-29

    The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity, totalling 1x10^35 cm^-2 s^-1 after 10 years of operation. A consequence of this increased luminosity is the expected radiation damage at 3000 fb^-1, requiring the tracking detectors to withstand hadron equivalences to over 1x10^16 1 MeV neutrons per cm^2. With the addition of increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 micron FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 micron thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 micron thick full size radial (Endcap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout...

  1. Forward Tracking with the silicon vertex detector at the CDF experiment in RUN II. Spurrekonstruktion in Vorwärtsrichtung mit dem Silizium-Vertexdetektor des CDF-Experiments in RUN II

    Energy Technology Data Exchange (ETDEWEB)

    Scheidle, Thorsten [Univ. of Karlsruhe (TH) (Germany)

    2007-02-01

    The Standard Model of particle physics describes the fundamental particles of matter and their interactions. In order to test the Standard Model, determine free parameters and search for new particles beyond the Standard Model, large accelerator complexes produce particle collisions which are recorded by large detectors. Until the start of the Large Hadron Collider at CERN, the Tevatron accelerator at Fermilab provides particle collisions with the highest center-of-mass energy of √s = 1.96 TeV. The two multipurpose detector systems CDF and DØ record the collisions. A multipurpose detector system is built of several specialized sub-detectors to measure different particle properties. A particle which passes the detector deposits energy by interacting with the detector material. A silicon strip detector and a wire drift chamber detect charged particles close to the collision point. The energy loss in these systems is relatively small, instead many different small energy depositions are produced by one passing particle. These so-called hits can be combined to a track, indicating the path of the particle. A homogeneous magnetic field surrounding the tracking system forces a charged particle to a helix path which allows a momentum measurement by measuring the curvature. The reconstruction of particle tracks is a non-trivial task. First all position measurements belonging to a particle along a hypothetical helix have to be found and then all position information has to be combined to a reconstructed track and its parameters. I focused my work on the track reconstruction in the silicon detector which provides a good position resolution of the measurements.

  2. Optical Constants of Silicon Carbide for Astrophysical Applications. II. Extending Optical Functions from Infrared to Ultraviolet Using Single-Crystal Absorption Spectra

    Science.gov (United States)

    Hofmeister, A. M.; Pitman, K. M.; Goncharov, A. F.; Speck, A. K.

    2009-05-01

    Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal structures of silicon carbide (SiC) are presented from 1200-35000 cm-1 (λ ~ 8-0.28 μm) and used to improve the accuracy of optical functions (n and k) from the infrared (IR) to the ultraviolet (UV). Comparison with previous λ ~ 6-20 μm thin-film spectra constrains the thickness of the films and verifies that recent IR reflectivity data provide correct values for k in the IR region. We extract n and k needed for radiative transfer models using a new "difference method," which utilizes transmission spectra measured from two SiC single-crystals with different thicknesses. This method is ideal for near-IR to visible regions where absorbance and reflectance are low and can be applied to any material. Comparing our results with previous UV measurements of SiC, we distinguish between chemical and structural effects at high frequency. We find that for all spectral regions, 3C (β-SiC) and the \\vec{E}\\bot \\vec{c} polarization of 6H (a type of α-SiC) have almost identical optical functions that can be substituted for each other in modeling astronomical environments. Optical functions for \\vec{E} \\Vert \\vec{c} of 6H SiC have peaks shifted to lower frequency, permitting identification of this structure below λ ~ 4 μm. The onset of strong UV absorption for pure SiC occurs near 0.2 μm, but the presence of impurities redshifts the rise to 0.33 μm. Optical functions are similarly impacted. Such large differences in spectral characteristics due to structural and chemical effects should be observable and provide a means to distinguish chemical variation of SiC dust in space.

  3. 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.

  4. Quantitative Electron-Excited X-Ray Microanalysis of Borides, Carbides, Nitrides, Oxides, and Fluorides with Scanning Electron Microscopy/Silicon Drift Detector Energy-Dispersive Spectrometry (SEM/SDD-EDS) and NIST DTSA-II.

    Science.gov (United States)

    Newbury, Dale E; Ritchie, Nicholas W M

    2015-10-01

    A scanning electron microscope with a silicon drift detector energy-dispersive X-ray spectrometer (SEM/SDD-EDS) was used to analyze materials containing the low atomic number elements B, C, N, O, and F achieving a high degree of accuracy. Nearly all results fell well within an uncertainty envelope of ±5% relative (where relative uncertainty (%)=[(measured-ideal)/ideal]×100%). Quantification was performed with the standards-based "k-ratio" method with matrix corrections calculated based on the Pouchou and Pichoir expression for the ionization depth distribution function, as implemented in the NIST DTSA-II EDS software platform. The analytical strategy that was followed involved collection of high count (>2.5 million counts from 100 eV to the incident beam energy) spectra measured with a conservative input count rate that restricted the deadtime to ~10% to minimize coincidence effects. Standards employed included pure elements and simple compounds. A 10 keV beam was employed to excite the K- and L-shell X-rays of intermediate and high atomic number elements with excitation energies above 3 keV, e.g., the Fe K-family, while a 5 keV beam was used for analyses of elements with excitation energies below 3 keV, e.g., the Mo L-family.

  5. A search for particle dark matter using cryogenic germanium and silicon detectors in the one- and two- tower runs of CDMS-II at Soudan

    Energy Technology Data Exchange (ETDEWEB)

    Ogburn, IV, Reuben Walter [Stanford Univ., CA (United States)

    2008-06-01

    Images of the Bullet Cluster of galaxies in visible light, X-rays, and through gravitational lensing confirm that most of the matter in the universe is not composed of any known form of matter. The combined evidence from the dynamics of galaxies and clusters of galaxies, the cosmic microwave background, big bang nucleosynthesis, and other observations indicates that 80% of the universe's matter is dark, nearly collisionless, and cold. The identify of the dar, matter remains unknown, but weakly interacting massive particles (WIMPs) are a very good candidate. They are a natural part of many supersymmetric extensions to the standard model, and could be produced as a nonrelativistic, thermal relic in the early universe with about the right density to account for the missing mass. The dark matter of a galaxy should exist as a spherical or ellipsoidal cloud, called a 'halo' because it extends well past the edge of the visible galaxy. The Cryogenic Dark Matter Search (CDMS) seeks to directly detect interactions between WIMPs in the Milky Way's galactic dark matter halo using crystals of germanium and silicon. Our Z-sensitive ionization and phonon ('ZIP') detectors simultaneously measure both phonons and ionization produced by particle interactions. In order to find very rare, low-energy WIMP interactions, they must identify and reject background events caused by environmental radioactivity, radioactive contaminants on the detector,s and cosmic rays. In particular, sophisticated analysis of the timing of phonon signals is needed to eliminate signals caused by beta decays at the detector surfaces. This thesis presents the firs two dark matter data sets from the deep underground experimental site at the Soudan Underground Laboratory in Minnesota. These are known as 'Run 118', with six detectors (1 kg Ge, 65.2 live days before cuts) and 'Run 119', with twelve detectors (1.5 kg Ge, 74.5 live days before cuts). They have

  6. 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...

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    KAUST Repository

    Hussain, Muhammad Mustafa

    2013-05-30

    Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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...

  4. 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.

  5. 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

  6. 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.

  7. Status of the CDF silicon detector

    Energy Technology Data Exchange (ETDEWEB)

    Grinstein, Sebastian; /Harvard U.

    2006-05-01

    The CDF Run II silicon micro-strip detector is an essential part of the heavy flavor tagging and forward tracking capabilities of the experiment. Since the commissioning period ended in 2002, about 85% of the 730 k readout channels have been consistently provided good data. A summary of the recent improvements in the DAQ system as well as experience of maintaining and operating such a large, complex detector are presented.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.)

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Slip Casting and Green Body Evaluation of 6% Yttria, 2% Alumina Silicon Nitride

    Science.gov (United States)

    1991-12-01

    Some Properrie of Aqucouw Silicon Nitride SuN- pensons. Ponrahkovaya Metallurgrya. no. 3 (159), March 1976, p. 37. 7. GREIL. P., NAGEL. A., STADELMANN ...H., and PETZOW, G. Revie%, Colloidal Proce=ing of Silicon Nitride Ceramics. Ceramic Materi- als and Componenls for Engines, p. 319. 8. STADELMANN II

  19. Experimental particle physics at the University of Pittsburgh. Progress report, November 1, 1995--October 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Boudreau, J.F.; Engels, E. Jr.; Shepard, P.F.; Thompson, J.A.

    1996-05-01

    This report covers the progress on two different tasks, Task A and Task B. Task A focuses on rare and semi-rare decays of {phi} and of the short-lived kaon with emphasis on those aspects needed in preparation for the proposed {Phi}-Factory measurements of CPT violation and {epsilon}{prime}/{epsilon} from the CP-violating decays of the K{sub L}K{sub S} final state. The second aspect of the kaon decay work is participation in the so-called rare kaon decay experiments, E865, at BNL. The major goals of Task B, Fermilab program, are as follows: (1) participation in the analysis of the E706 data taken during the 1990--1991 fixed target run at Fermilab and (2) the continuation of the work with the CDF collaboration particularly the SVX II upgrade. The E706 part of the program involves the completion of publications reporting the results of the 1990--91 data run. The analysis of these data is now mature and physics results are emerging. The CDF program involves a dedicated effort to the design of a silicon vertex detector upgrade, SVX II, to be accomplished by the time Fermilab run II collider run (1999). In addition they are participating in the 1993--1995 collide run Ib and actively analyzing the data from both runs Ia and Ib.

  20. Tribological Properties of Silicone Rubber-Based Ceramizable Composites Destined for Wire Covers. Part II. Studies of Ball-on-Plate, Plate-on-Plate and Ring-on-Plate Friction Contact

    Directory of Open Access Journals (Sweden)

    R. Anyszka

    2016-09-01

    Full Text Available Tribological properties of commercially available silicone-based ceramizable composites were studied. Friction forces of three different types of ceramizable composites were measured against three different-shape steel samples. Each friction pair contact was loaded with 15, 30, 45 or 60 N. Conducted studies reveal that tribological behavior of the composites vary considerably depending on the composite type and friction contact. However, friction force was increasing with an increase of the load, which mean that the composites behave accordingly to the classic friction theory.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. Internal alignement of the BABAR silicon vertex tracking detector

    CERN Document Server

    Brown, D; Roberts, D

    2007-01-01

    The BABAR Silicon Vertex Tracker (SVT ) is a five-layer double-sided silicon detector designed to provide precise measurements of the position and direction of primary tracks, and to fully reconstruct low-momentum tracks produced in e+e¡ collisions at the PEP-II asymmetric collider at Stanford Linear Accelerator Center. This paper describes the design, implementation, performance and validation of the local alignment procedure used to determine the relative positions and orientations of the 340 Silicon Vertex Trackerwafers. This procedure uses a tuned mix of lab-bench measurements and complementary in-situ experimental data to control systematic distortions. Wafer positions and orientations are determined by minimizing a Â2 computed using these data for each wafer individually, iterating to account for between-wafer correlations. A correction for aplanar distortions of the silicon wafers is measured and applied. The net effect of residual mis-alignments on relevant physical variables evaluated in special co...

  6. EDITORIAL: Special issue on silicon photonics

    Science.gov (United States)

    Reed, Graham; Paniccia, Mario; Wada, Kazumi; Mashanovich, Goran

    2008-06-01

    The technology now known as silicon photonics can be traced back to the pioneering work of Soref in the mid-1980s (see, for example, Soref R A and Lorenzo J P 1985 Electron. Lett. 21 953). However, the nature of the research conducted today, whilst it builds upon that early work, is unrecognizable in terms of technology metrics such as device efficiency, device data rate and device dimensions, and even in targeted applications areas. Today silicon photonics is still evolving, and is enjoying a period of unprecedented attention in terms of research focus. This has resulted in orders-of-magnitude improvement in device performance over the last few years to levels many thought were impossible. However, despite the existence of the research field for more than two decades, silicon is still regarded as a 'new' optical material, one that is being manipulated and modified to satisfy the requirements of a range of applications. This is somewhat ironic since silicon is one of the best known and most thoroughly studied materials, thanks to the electronics industry that has made silicon its material of choice. The principal reasons for the lack of study of this 'late developer' are that (i) silicon is an indirect bandgap material and (ii) it does not exhibit a linear electro-optic (Pockels) effect. The former condition means that it is difficult to make a laser in silicon based on the intrinsic performance of the material, and consequently, in recent years, researchers have attempted to modify the material to artificially engineer the conditions for lasing to be viable (see, for example, the review text, Jalali B et al 2008 Silicon Lasers in Silicon Photonics: The State of the Art ed G T Reed (New York: Wiley)). The latter condition means that optical modulators are intrinsically less efficient in silicon than in some other materials, particularly when targeting the popular telecommunications wavelengths around 1.55 μm. Therefore researchers have sought alternative

  7. Silicon release coating, method of making same, and method of using same

    Science.gov (United States)

    Jonczyk, Ralf [Wilmington, DE

    2011-11-22

    A method of making a release coating includes the following steps: forming a mixture that includes (a) solid components comprising (i) 20-99% silicon by weight and (ii) 1-80% silicon nitride by weight and (b) a solvent; applying the mixture to an inner portion of a crucible or graphite board adapted to form an ingot or wafer comprising silicon; and annealing the mixture in a nitrogen atmosphere at a temperature ranging from 1000 to 2000.degree. C. The invention may also relate to release coatings and methods of making a silicon ingot or wafer including the use of a release coating.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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 ...

  3. 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.

  4. 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.

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Silicon: the evolution of its use in biomaterials.

    Science.gov (United States)

    Henstock, J R; Canham, L T; Anderson, S I

    2015-01-01

    In the 1970s, several studies revealed the requirement for silicon in bone development, while bioactive silicate glasses simultaneously pioneered the current era of bioactive materials. Considerable research has subsequently focused on the chemistry and biological function of silicon in bone, demonstrating that the element has at least two separate effects in the extracellular matrix: (i) interacting with glycosaminoglycans and proteoglycans during their synthesis, and (ii) forming ionic substitutions in the crystal lattice structure of hydroxyapatite. In addition, the dissolution products of bioactive glass (predominantly silicic acids) have significant effects on the molecular biology of osteoblasts in vitro, regulating the expression of several genes including key osteoblastic markers, cell cycle regulators and extracellular matrix proteins. Researchers have sought to capitalize on these effects and have generated a diverse array of biomaterials, which include bioactive glasses, silicon-substituted hydroxyapatites and pure, porosified silicon, but all these materials share similarities in the mechanisms that result in their bioactivity. This review discusses the current data obtained from original research in biochemistry and biomaterials science supporting the role of silicon in bone, comparing both the biological function of the element and analysing the evolution of silicon-containing biomaterials. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. 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.

  16. 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.)

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Radiation Hardening of Silicon Detectors

    CERN Multimedia

    Leroy, C; Glaser, M

    2002-01-01

    %RD48 %title\\\\ \\\\Silicon detectors will be widely used in experiments at the CERN Large Hadron Collider where high radiation levels will cause significant bulk damage. In addition to increased leakage current and charge collection losses worsening the signal to noise, the induced radiation damage changes the effective doping concentration and represents the limiting factor to long term operation of silicon detectors. The objectives are to develop radiation hard silicon detectors that can operate beyond the limits of the present devices and that ensure guaranteed operation for the whole lifetime of the LHC experimental programme. Radiation induced defect modelling and experimental results show that the silicon radiation hardness depends on the atomic impurities present in the initial monocrystalline material.\\\\ \\\\ Float zone (FZ) silicon materials with addition of oxygen, carbon, nitrogen, germanium and tin were produced as well as epitaxial silicon materials with epilayers up to 200 $\\mu$m thickness. Their im...

  4. 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 ...

  5. Phase transformation in AFM silicon tips

    Science.gov (United States)

    Kopycinska-Müller, M.; Barth, M.; Küttner, M.; Köhler, B.

    2017-09-01

    We confirmed the occurrence of phase transformations in an atomic force microscopy silicon tip during loading and unloading experiments performed on a polycrystalline Ti sample. The influence of the phase transformations on the effective mechanical and electrical properties of the tip was observed with the help of load-unload curves measured simultaneously for the tip-sample contact stiffness k * and the effective electrical resistance of the system R eff. We used the atomic force acoustic microscopy (AFAM) method to determine the values of k *. To measure the changes in R eff, we combined a high voltage source/measure unit with the existing AFAM system. The data obtained showed that the phase transformation from Si-I to Si-II is preceded by other structural changes such as formation of distorted diamond structures and formation of Si-III. This conclusion was reached after observing a small hysteretic behavior in the load-unload stiffness curve accompanied by only very small changes in the resistance of the tip-sample system occurring on the unloading. The coinciding of a sudden increase in the values of the contact stiffness with a decrease in the resistance of the system indicated that the formation of metallic Si-II occurred in the subsequent measurements. The interpretation of our results found confirmation in the results of molecular dynamics and atomistic simulations performed for silicon under nanoindentation experiments.

  6. Geneva University - Silicon photomultiplier : features and applications

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 7 March 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 11.15 a.m. - Science II, Auditoire 1S081, 30, quai Ernest-Ansermet, 1211 Genève 4 SILICON PHOTOMULTIPLIER : FEATURES AND APPLICATIONS Dr Giulio SARACINO   University of Naples, Federico II   Silicon photomultipliers were developed about ten years ago and their use, unlike traditional photomultiplier tubes, is increasing more and more. They are an evolution of the avalanche photodiode working in Geiger mode regime. Hundreds of such diodes are connected in parallel, allowing single photon response, high detection efficiency, high gain at low bias voltage and very good timing performance. In spite of their Geiger regime, they can be considered linear devices, until the number of photon...

  7. 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.

  8. 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).

  9. 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.

  10. Spin-photon entanglement interfaces in silicon carbide defect centers

    Science.gov (United States)

    Economou, Sophia E.; Dev, Pratibha

    2016-12-01

    Optically active spins in solid-state systems can be engineered to emit photons that are entangled with the spin in the solid. This allows for applications such as quantum communications, quantum key distribution, and distributed quantum computing. Recently, there has been a strong interest in silicon carbide defects, as they emit very close to the telecommunication wavelength, making them excellent candidates for long range quantum communications. In this work we develop explicit schemes for spin-photon entanglement in several SiC defects: the silicon monovacancy, the silicon divacancy, and the NV center in SiC. Distinct approaches are given for (i) single-photon and spin entanglement and (ii) the generation of long strings of entangled photons. The latter are known as cluster states and comprise a resource for measurement-based quantum information processing.

  11. 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 ...

  12. 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.

    CERN Document Server

    Sfyrla, Anna

    2008-01-01

    Ce travail de thèse est composé de deux parties. La première présente un travail de recherche sur la production de paires de bosons $WW$ et $WZ$ dans les états finaux de lepton, neutrino et jets, menée à l'expérience CDF II. Un réseau neuronal artificiel est utilisé pour la sélection des données, qui correspondent à une luminosité intégrée de 1.2 fb$^{-1}$. Le résultat fixe une limite supérieure à la section efficace (95% CL) de $\\sigma \\times Br(W\\rightarrow \\ell \

  13. The Belle II Detector

    Science.gov (United States)

    Piilonen, Leo; Belle Collaboration, II

    2017-01-01

    The Belle II detector is now under construction at the KEK laboratory in Japan. This project represents a substantial upgrade of the Belle detector (and the KEKB accelerator). The Belle II experiment will record 50 ab-1 of data, a factor of 50 more than that recorded by Belle. This large data set, combined with the low backgrounds and high trigger efficiencies characteristic of an e+e- experiment, should provide unprecedented sensitivity to new physics signatures in B and D meson decays, and in τ lepton decays. The detector comprises many forefront subsystems. The vertex detector consists of two inner layers of silicon DEPFET pixels and four outer layers of double-sided silicon strips. These layers surround a beryllium beam pipe having a radius of only 10 mm. Outside of the vertex detector is a large-radius, small-cell drift chamber, an ``imaging time-of-propagation'' detector based on Cerenkov radiation for particle identification, and scintillating fibers and resistive plate chambers used to identify muons. The detector will begin commissioning in 2017.

  14. 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 ...

  15. Silicon tracking detectors in high-energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Frank, E-mail: Frank.Hartmann@cern.ch [Institut fuer Experimentelle Kernphysik, KIT, Karlsruhe (Germany)

    2012-02-21

    Since the fifties, semiconductors have been used as energy spectrometers, mainly in unsegmented ways. With the planar technique of processing silicon sensors in unprecedented precession, strip-like segmentation has allowed precise tracking and even vertexing, culminating in the early eighties with NA11 in the tagging of heavy flavor quarks - here the c-quark. With the later miniaturization of electronics, dense detector application was made possible, and large-scale systems were established in the heart of all LEP detectors, permitting vertexing in barrel-like detectors. At the time of LEP and the TEVATRON, tasks were still bifurcated. Small silicon detectors (up to three layers) did the vertexing and further out, gaseous detectors (e.g., drift chambers or time-projection chambers) with larger lever arms did the tracking. In RUN II of the CDF detector, larger silicon tracking devices, still complemented by a huge drift chamber, began to use a stand-alone tracking. At the LHC, ATLAS and CMS bifurcate in a slightly different way. Silicon pixel detectors are responsible for the vertexing, and large volume silicon strip detectors (up to 14 layers) are the main tracking devices. Silicon tracking systems are a fundamental part of modern multipurpose high-energy physics experiments. Despite the vertexing and thus the heavy quark tagging, silicon tracking detectors in combination with a strong B-field deliver the most accurate momentum measurement, and for a large range, also the best energy measurement. In this paper, the functionality of pixel and strip sensors will be introduced, and historical examples will be given to highlight the different implementations of the past 30 years.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. The BaBar silicon vertex tracker, performance and running experience

    CERN Document Server

    Re, V; Bozzi, C; Carassiti, V; Cotta-Ramusino, A; Piemontese, L; Breon, A B; Brown, D; Clark, A R; Goozen, F; Hernikl, C; Kerth, L T; Gritsan, A; Lynch, G; Perazzo, A; Roe, N A; Zizka, G; Roberts, D; Schieck, J; Brenna, E; Citterio, M; Lanni, F; Palombo, F; Ratti, L; Manfredi, P F; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bosi, F; Bucci, F; Calderini, G; Carpinelli, M; Ceccanti, M; Forti, F; Gagliardi, D J; Giorgi, M A; Lusiani, A; Mammini, P; Morganti, M; Morsani, F; Neri, N; Paoloni, E; Profeti, A; Rama, M; Rizzo, G; Sandrelli, F; Simi, G; Triggiani, G; Walsh, J; Burchat, Patricia R; Cheng, C; Kirkby, D; Meyer, T I; Roat, C; Bóna, M; Bianchi, F; Gamba, D; Trapani, P; Bosisio, L; Della Ricca, G; Dittongo, S; Lanceri, L; Pompili, A; Poropat, P; Rashevskaia, I; Vuagnin, G; Burke, S; Callahan, D; Campagnari, C; Dahmes, B; Hale, D; Hart, P; Kuznetsova, N; Kyre, S; Levy, S; Long, O; May, J; Mazur, M; Richman, J; Verkerke, W; Witherell, M; Beringer, J; Eisner, A M; Frey, A; Grillo, A A; Grothe, M; Johnson, R P; Kröger, W; Lockman, W S; Pulliam, T; Rowe, W; Schmitz, R E; Seiden, A; Spencer, E N; Turri, M; Walkowiak, W; Wilder, M; Wilson, M; Charles, E; Elmer, P; Nielsen, J; Orejudos, W; Scott, I; Zobernig, H

    2002-01-01

    The Silicon Vertex Tracker (SVT) of the BaBar experiment at the PEP-II asymmetric B factory is a five-layer double-sided, AC-coupled silicon microstrip detector. It represents the crucial element to precisely measure the decay position of B mesons and extract time-dependent CP asymmetries. The SVT architecture is shown and its performance is described, with emphasis on hit resolutions and efficiencies.

  1. The design and construction of the BaBar silicon vertex tracker

    CERN Document Server

    Bozzi, C; Ramusino, A C; Dittongo, S; Folegani, M; Piemontese, L; Abbott, B K; Breon, A B; Clark, A R; Dow, S; Fan, Q; Goozen, F; Hernikl, C; Karcher, A; Kerth, L T; Kipnis, I; Kluth, S; Lynch, G; Levi, M; Luft, P; Luo, L; Nyman, M A; Pedrali-Noy, M; Roe, N A; Zizka, G; Roberts, D; Barni, D; Brenna, E; Defendi, I; Forti, A C; Giugni, D; Lanni, F; Palombo, F; Vaniev, V; Leona, A; Mandelli, E; Manfredi, P F; Perazzo, A; Re, V; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bosi, F; Calderini, G; Carpinelli, M; Dutra, F; Forti, F; Gagliardi, D; Giorgi, M A; Lusiani, A; Mammini, P; Morganti, M; Morsani, F; Paoloni, E; Profeti, A; Rama, M; Rampino, G; Rizzo, G; Sandrelli, F; Simi, G; Triggiani, G; Tritto, S; Vitale, R; Burchat, Patricia R; Cheng, C; Kirkby, D; Meyer, T; Roat, C; Bóna, M; Bianchi, F; Daudo, F; Girolamo, B D; Gamba, D; Giraudo, G; Grosso, P; Romero, A; Smol, A; Trapani, P; Zanin, D; Bosisio, L; Della Ricca, G; Lanceri, L; Pompili, A; Poropat, P; Prest, M; Rastelli, C; Vallazza, E; Vuagnin, G; Hast, C; Potter, E P; Sharma, V; Burke, S; Callahan, D; Campagnari, C; Dahmes, B; Eppich, A; Hale, D; Hall, K; Hart, P; Kuznetsova, N; Kyre, S; Levy, S; Long, O; May, J; Richman, J; Verkerke, W; Witherell, M; Beringer, J; Eisner, A M; Frey, A; Grillo, A; Grothe, M; Johnson, R; Kröger, W; Lockman, W; Pulliam, T; Rowe, W; Schmitz, R; Seiden, A; Spencer, E; Turri, M; Wilder, M; Charles, E; Elmer, P; Nielsen, J; Orejudos, W; Scott, I; Walsh, J; Zobernig, H

    2000-01-01

    The Silicon Vertex Tracker (SVT) of the BaBar experiment at the PEP-II asymmetric B factory consists of five layers of double-sided, AC-coupled silicon strip detectors. The detectors are readout with a custom IC, capable of simultaneous acquisition, digitization and transmission of data. The SVT geometry is shown and the construction phases of its modules are described in detail, with emphasis on the bending procedures needed for the arch-modules of the outer layers.

  2. 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.

  3. Growth undercooling in multi-crystalline pure silicon and in silicon containing light impurities (C and O)

    Science.gov (United States)

    Riberi-Béridot, T.; Tsoutsouva, M. G.; Regula, G.; Reinhart, G.; Périchaud, I.; Baruchel, J.; Mangelinck-Noël, N.

    2017-05-01

    Undercooling during the solidification of silicon is an essential parameter that plays a major role in grain nucleation and growth. In this study, the undercooling of the solid-liquid interface during growth of multi-crystalline silicon samples is measured for two types of silicon: pure, and containing light elements (carbon and oxygen) to assess and compare their impact on crystal growth. The solid-liquid interface undercooling is measured using in situ and real time X-ray synchrotron imaging during solidification. As a subsequent step, ex situ Electron Backscattered Diffraction (EBSD) is performed to obtain information about the crystalline structure, the grain orientation and the grain boundary character. Two main conclusions arise: (i) the undercooling of the global solid-liquid front increases linearly with the growth rate which indicates uniform attachment, i.e. all atoms are equivalent, (ii) the same trend is observed for pure silicon and silicon containing carbon and oxygen. Indeed, the growth law obtained is comparable in both cases, which suggests that the solutal effect is negligible as concern the undercooling in the case of a contamination with carbon (C) and oxygen (O). However, there is a clear effect of the impurity presence on the crystalline structure and grain boundary type distribution. Many grains nucleate during growth in samples containing C and O, which suggests the presence of precipitates on which grain nucleation is favored.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Technoshamanic Visions from the Underworld II

    DEFF Research Database (Denmark)

    Audio-visual arts installation/VJ mix with accompanying paintings, for presentation at the Carbon Meets Silicon II exhibition, Glyndwr University, Wrexham. Accompanying article in proceedings/exhibition catalogue. The audio-visual work was also presented at Breaking Convention 2017, University...

  10. 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)

  11. 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.)

  12. An Annotated Bibliography on Silicon Nitride for Structural Applications

    Science.gov (United States)

    1977-03-01

    microscopy. The major oxidation product is cristobalite which forms around internal pores (Stage I) and eventually as a dense surface layer (Stage II...specimen is not cooled through the cristobalite inversion temperature at ~250 C. 21. Engel, W., Gugel, E., and Thuemmler, F., "Fluage du niture de...the reaction. 35. Grieveson, P., Jack, K. H., and Wild, S., "The Crystal Structures of Alpha and Beta Silicon and Germanium Nitrides", Special

  13. ATLAS Inner Detector (Pixel Detector and Silicon Tracker)

    CERN Multimedia

    ATLAS Outreach

    2006-01-01

    To raise awareness of the basic functions of the Pixel Detector and Silicon Tracker in the ATLAS detector on the LHC at CERN. This colorful 3D animation is an excerpt from the film "ATLAS-Episode II, The Particles Strike Back." Shot with a bug's eye view of the inside of the detector. The viewer is taken on a tour of the inner workings of the detector, seeing critical pieces of the detector and hearing short explanations of how each works.

  14. 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.

  15. 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.

  16. Silicon Chemical Vapor Deposition Process Using a Half-Inch Silicon Wafer for Minimal Manufacturing System

    Science.gov (United States)

    Li, Ning; Habuka, Hitoshi; Ikeda, Shin-ichi; Hara, Shiro

    A chemical vapor deposition reactor for producing thin silicon films was designed and developed for achieving a new electronic device production system, the Minimal Manufacturing, using a half-inch wafer. This system requires a rapid process by a small footprint reactor. This was designed and verified by employing the technical issues, such as (i) vertical gas flow, (ii) thermal operation using a highly concentrated infrared flux, and (iii) reactor cleaning by chlorine trifluoride gas. The combination of (i) and (ii) could achieve a low heating power and a fast cooling designed by the heat balance of the small wafer placed at a position outside of the reflector. The cleaning process could be rapid by (iii). The heating step could be skipped because chlorine trifluoride gas was reactive at any temperature higher than room temperature.

  17. 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.

  18. 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...

  19. 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).

  20. A Custom Made Intrinsic Silicone Shade Guide for Indian Population.

    Science.gov (United States)

    Anitha, K V; Behanam, Mohammed; Ahila, S C; Jei, J Brintha

    2016-04-01

    Replication of natural skin colour in maxillofacial prosthesis has been traditionally done using trial and error method, as concrete shade guides are unavailable till date. Hence a novel custom made intrinsic silicone shade guide has been attempted for Indian population. Reconstruction of maxillofacial defects is challenging, as achieving an aesthetic result is not always easy. A concoction of a novel intrinsic silicone shade guide was contemplated for the study and its reproducibility in clinical practice was analysed. Medical grade room temperature vulcanising silicone was used for the fabrication of shade tabs. The shade guide consisted of three main groups I, II and III which were divided based upon the hues yellow, red and blue respectively. Five distinct intrinsic pigments were added in definite proportions to subdivide each group of different values from lighter to darker shades. A total number of 15 circular shade tabs comprised the guide. To validate the usage of the guide, visual assessment of colour matching was done by four investigators to investigate the consent of perfect colour correspondence. Data was statistically analysed using kappa coefficients. The kappa values were found to be 0.47 to 0.78 for yellow based group I, 0.13 to 0.65 for red based group II, and 0.07 to 0.36 for blue based group III. This revealed that the shade tabs of yellow and red based hues matched well and showed a statistically good colour matching. This intrinsic silicone shade guide can be effectively utilised for fabrication of maxillofacial prosthesis with silicone in Indian population. A transparent colour formula with definite proportioning of intrinsic pigments is provided for obtaining an aesthetic match to skin tone.

  1. 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

  2. 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

  3. 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...

  4. The Alignment of the CMS Silicon Tracker

    CERN Document Server

    Lampen, Pekka Tapio

    2013-01-01

    The CMS all-silicon tracker consists of 16588 modules, embedded in a solenoidal magnet providing a field of B = 3.8 T. The targeted performance requires that the alignment determines the module positions with a precision of a few micrometers. Ultimate local precision is reached by the determination of sensor curvatures, challenging the algorithms to determine about 200k parameters simultaneously, as is feasible with the Millepede II program. The main remaining challenge are global distortions that systematically bias the track parameters and thus physics measurements. They are controlled by adding further information into the alignment workflow, e.g. the mass of decaying resonances or track data taken with B = 0 T. To make use of the latter and also to integrate the determination of the Lorentz angle into the alignment procedure, the alignment framework has been extended to treat position sensitive calibration parameters. This is relevant since due to the increased LHC luminosity in 2012, the Lorentz angle ex...

  5. 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.

  6. 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 ...

  7. 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...

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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....

  19. Technoshamanic Visions from the Underworld II

    DEFF Research Database (Denmark)

    Weinel, Jonathan

    2017-01-01

    such as painting, other materials are also designed by creating pixel-art and by programming generative computer animations. These are ultimately combined with psychedelic music to form composites, which are mixed live with audio-reactive effects, using the VJ software VDMX. Aesthetically the work draws upon......Technoshamanic Visions from the Underworld II is an audio-visual art installation by Jon Weinel. The artwork consists of a video projection in which various analogue and digital animations are created as a compliment to music. While parts of the animations are created with traditional techniques...... the artist’s extensive practice-based research regarding altered states of consciousness. -- The paper describes an audio-visual arts installation/VJ mix with accompanying paintings, which was presented at the Carbon Meets Silicon II exhibition, Glyndwr University, Wrexham. Carbon Meets Silicon II was an art...

  20. Corrosion resistant three-dimensional nanotextured silicon for water photo-oxidation

    Science.gov (United States)

    Carter, Rachel; Chatterjee, Shahana; Gordon, Evan; Share, Keith; Erwin, William R.; Cohn, Adam P.; Bardhan, Rizia; Pint, Cary L.

    2015-10-01

    We demonstrate the ability to chemically transform bulk silicon into a nanotextured surface that exhibits excellent electrochemical stability in aqueous conditions for water photo-oxidation. Conformal defective graphene coatings on nanotextured silicon formed by thermal treatment enable over 50× corrosion resistance in aqueous electrolytes based upon Tafel analysis and impedance spectroscopy. This enables nanotextured silicon as an effective oxygen-evolution photoanode for water splitting with saturation current density measured near 35 mA cm-2 under 100 mW cm-2 (1 sun) illumination. Our approach builds upon simple and scalable processing techniques with silicon to develop corrosion resistant electrodes that can benefit a broad range of catalytic and photocatalytic applications.We demonstrate the ability to chemically transform bulk silicon into a nanotextured surface that exhibits excellent electrochemical stability in aqueous conditions for water photo-oxidation. Conformal defective graphene coatings on nanotextured silicon formed by thermal treatment enable over 50× corrosion resistance in aqueous electrolytes based upon Tafel analysis and impedance spectroscopy. This enables nanotextured silicon as an effective oxygen-evolution photoanode for water splitting with saturation current density measured near 35 mA cm-2 under 100 mW cm-2 (1 sun) illumination. Our approach builds upon simple and scalable processing techniques with silicon to develop corrosion resistant electrodes that can benefit a broad range of catalytic and photocatalytic applications. Electronic supplementary information (ESI) available: (i) Experimental details, (ii) Nyquist plot from EIS data, (iii) FTIR of H-terminated silicon, (iv) reflectance measurements to quantify light trapping in nanotextured silicon, (v) LSV from Tafel analysis, and (vi) J-V curves for H-terminated flat samples, (vii) stability test of photoanode, and (viii) forward and reverse scans for each sample type. See DOI: 10

  1. Physiological and proteomic analysis in chloroplasts of Solanum lycopersicum L. under silicon efficiency and salinity stress.

    Science.gov (United States)

    Muneer, Sowbiya; Park, Yoo Gyeong; Manivannan, Abinaya; Soundararajan, Prabhakaran; Jeong, Byoung Ryong

    2014-11-26

    Tomato plants often grow in saline environments in Mediterranean countries where salt accumulation in the soil is a major abiotic stress that limits its productivity. However, silicon (Si) supplementation has been reported to improve tolerance against several forms of abiotic stress. The primary aim of our study was to investigate, using comparative physiological and proteomic approaches, salinity stress in chloroplasts of tomato under silicon supplementation. Tomato seedlings (Solanum lycopersicum L.) were grown in nutrient media in the presence or absence of NaCl and supplemented with silicon for 5 days. Salinity stress caused oxidative damage, followed by a decrease in silicon concentrations in the leaves of the tomato plants. However, supplementation with silicon had an overall protective effect against this stress. The major physiological parameters measured in our studies including total chlorophyll and carotenoid content were largely decreased under salinity stress, but were recovered in the presence of silicon. Insufficient levels of net-photosynthesis, transpiration and stomatal conductance were also largely improved by silicon supplementation. Proteomics analysis of chloroplasts analyzed by 2D-BN-PAGE (second-dimensional blue native polyacrylamide-gel electrophoresis) revealed a high sensitivity of multiprotein complex proteins (MCPs) such as photosystems I (PSI) and II (PSII) to the presence of saline. A significant reduction in cytochrome b6/f and the ATP-synthase complex was also alleviated by silicon during salinity stress, while the complex forms of light harvesting complex trimers and monomers (LHCs) were rapidly up-regulated. Our results suggest that silicon plays an important role in moderating damage to chloroplasts and their metabolism in saline environments. We therefore hypothesize that tomato plants have a greater capacity for tolerating saline stress through the improvement of photosynthetic metabolism and chloroplast proteome expression

  2. Physiological and Proteomic Analysis in Chloroplasts of Solanum lycopersicum L. under Silicon Efficiency and Salinity Stress

    Directory of Open Access Journals (Sweden)

    Sowbiya Muneer

    2014-11-01

    Full Text Available Tomato plants often grow in saline environments in Mediterranean countries where salt accumulation in the soil is a major abiotic stress that limits its productivity. However, silicon (Si supplementation has been reported to improve tolerance against several forms of abiotic stress. The primary aim of our study was to investigate, using comparative physiological and proteomic approaches, salinity stress in chloroplasts of tomato under silicon supplementation. Tomato seedlings (Solanum lycopersicum L. were grown in nutrient media in the presence or absence of NaCl and supplemented with silicon for 5 days. Salinity stress caused oxidative damage, followed by a decrease in silicon concentrations in the leaves of the tomato plants. However, supplementation with silicon had an overall protective effect against this stress. The major physiological parameters measured in our studies including total chlorophyll and carotenoid content were largely decreased under salinity stress, but were recovered in the presence of silicon. Insufficient levels of net-photosynthesis, transpiration and stomatal conductance were also largely improved by silicon supplementation. Proteomics analysis of chloroplasts analyzed by 2D-BN-PAGE (second-dimensional blue native polyacrylamide-gel electrophoresis revealed a high sensitivity of multiprotein complex proteins (MCPs such as photosystems I (PSI and II (PSII to the presence of saline. A significant reduction in cytochrome b6/f and the ATP-synthase complex was also alleviated by silicon during salinity stress, while the complex forms of light harvesting complex trimers and monomers (LHCs were rapidly up-regulated. Our results suggest that silicon plays an important role in moderating damage to chloroplasts and their metabolism in saline environments. We therefore hypothesize that tomato plants have a greater capacity for tolerating saline stress through the improvement of photosynthetic metabolism and chloroplast proteome

  3. 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.

  4. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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)

  11. Thin Silicon Solar Cells: A Path to 35% Shockley-Queisser Limits

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Laura; Boccard, Mathieu; Williams, Joshua; Jeffries, April; Gangam, Srikanth; Ghosh, Kunal; Honsberg, Christiana; Bowden, Stuart; Holman, Zachary; Atwater, Harry; Buonassisi, Tonio; Bremner, Stephen; Green, Martin; Balif, Christoph; Bertoni, Mariana

    2014-06-08

    Crystalline silicon technology is expected to remain the leading photovoltaic industry workhorse for decades. We present here the objectives and workplan of a recently launched project funded by the U.S. Department of Energy through the Foundational Program to Advance Cell Efficiency II (FPACE II), which aims at leading crystalline silicon to an efficiency breakthrough. The project will tackle fundamental approach of materials design, defect engineering, device simulations and materials growth and characterization. Among the main novelties, the implementation of carrier selective contacts made of wide bandgap material or stack of materials is investigated for improved passivation, carrier extraction and carrier transport. Based on an initial selection of candidate materials, preliminary experiments are conducted to verify the suitability of their critical parameters as well as preservation of the silicon substrate surface and bulk properties. The target materials include III-V and metal-oxide materials.

  12. Online analysis of oxygen inside silicon-glass microreactors with integrated optical sensors

    DEFF Research Database (Denmark)

    Ehgartner, Josef; Sulzer, Philipp; Burger, Tobias

    2016-01-01

    presented and consists of a polystyrene- silicone rubber composite matrix with embedded palladium(II) or platinum(II) meso-tetra(4-fluorophenyl) tetrabenzoporphyrin (PdTPTBPF and PtTPTBPF) as oxygen sensitive dye. The resulting sensor layers have several advantages such as being excitable with red light...... measurements in the frequency domain (phase shifts). The fabrication and patterning of sensor layers down to a size of 100 μm in diameter is performed via automated airbrush spraying and was used for the integration into silicon-glass microreactors. A novel and easily processable sensor material is also...... a resolution of 0.2-0.6 hPa at low oxygen concentrations (silicon-glass microreactors which were manufactured using mass production compatible processes. The obtained microreactors were applied for online...

  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. Temperature dependence of electron impact ionization coefficient in bulk silicon

    Science.gov (United States)

    Ahmed, Mowfaq Jalil

    2017-09-01

    This work exhibits a modified procedure to compute the electron impact ionization coefficient of silicon for temperatures between 77 and 800K and electric fields ranging from 70 to 400 kV/cm. The ionization coefficients are computed from the electron momentum distribution function through solving the Boltzmann transport equation (BTE). The arrangement is acquired by joining Legendre polynomial extension with BTE. The resulting BTE is solved by differences-differential method using MATLAB®. Six (X) equivalent ellipsoidal and non-parabolic valleys of the conduction band of silicon are taken into account. Concerning the scattering mechanisms, the interval acoustic scattering, non-polar optical scattering and II scattering are taken into consideration. This investigation showed that the ionization coefficients decrease with increasing temperature. The overall results are in good agreement with previous experimental and theoretical reported data predominantly at high electric fields.

  15. 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.

  16. 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...

  17. Micro structured coupling elements for 3D silicon optical interposer

    Science.gov (United States)

    Charania, Sujay; Lüngen, Sebastian; Al-Husseini, Zaid; Killge, Sebastian; Nieweglowski, Krzysztof; Neumann, Niels; Plettemeier, Dirk; Bock, Karlheinz; Bartha, Johann W.

    2017-05-01

    Current trends in electronic industry, such as Internet of Things (IoT) and Cloud Computing call for high interconnect bandwidth, increased number of active devices and high IO count. Hence the integration of on silicon optical waveguides becomes an alternative approach to cope with the performance demands. The application and fabrication of horizontal (planar) and vertical (Through Silicon Vias - TSVs) optical waveguides are discussed here. Coupling elements are used to connect both waveguide structures. Two micro-structuring technologies for integration of coupling elements are investigated: μ-mirror fabrication by nanoimprint (i) and dicing technique (ii). Nanoimprint technology creates highly precise horizontal waveguides with polymer (refractive index nC = 1.56 at 650 nm) as core. The waveguide ends in reflecting facets aligned to the optical TSVs. To achieve Total Internal Reflection (TIR), SiO2 (nCl = 1.46) is used as cladding. TSVs (diameter 20-40μm in 200-380μm interposer) are realized by BOSCH process1, oxidation and SU-8 filling techniques. To carry out the imprint, first a silicon structure is etched using a special plasma etching process. A polymer stamp is then created from the silicon template. Using this polymer stamp, SU-8 is imprinted aligned to vertical TSVs over Si surface.Waveguide dicing is presented as a second technology to create coupling elements on polymer waveguides. The reflecting mirror is created by 45° V-shaped dicing blade. The goal of this work is to develop coupling elements to aid 3D optical interconnect network on silicon interposer, to facilitate the realization of the emerging technologies for the upcoming years.

  18. Stabilization of low valent silicon fluorides in the coordination sphere of transition metals.

    Science.gov (United States)

    Azhakar, Ramachandran; Ghadwal, Rajendra S; Roesky, Herbert W; Wolf, Hilke; Stalke, Dietmar

    2012-02-01

    Silicon(II) fluoride is unstable; therefore, isolation of the stable species is highly challenging and was not successful during the last 45 years. SiF(2) is generally generated in the gas phase at very high temperatures (~1100-1200 °C) and low pressures and readily disproportionates or polymerizes. We accomplished the syntheses of stable silicon(II) fluoride species by coordination of silicon(II) to transition metal carbonyls. Silicon(II) fluoride compounds L(F)Si·M(CO)(5) {M = Cr (4), Mo (5), W(6)} (L = PhC(NtBu)(2)) were prepared by metathesis reaction from the corresponding chloride with Me(3)SnF. However, the chloride derivatives L(Cl)Si·M(CO)(5) {M = Cr (1), Mo (2), W(3)} (L = PhC(NtBu)(2)) were prepared by the treatment of transition metal carbonyls with L(Cl)Si. Direct fluorination of L(Cl)Si with Me(3)SnF resulted in oxidative addition products. Compounds 4-6 are stable at ambient temperature under an inert atmosphere of nitrogen. Compounds 4-6 were characterized by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. The molecular structures of 4 and 6 were unambiguously established by single-crystal X-ray diffraction. Compounds 4 and 6 are the first structurally characterized fluorides, after the discovery of SiF(2) about four and a half decades ago. © 2011 American Chemical Society

  19. 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.

  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. 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

  3. 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

  4. 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....

  5. 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.

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. 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.

  11. 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.

  12. 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.))

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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...

  1. 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

  2. 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...

  3. 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...

  4. 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...

  5. 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

  6. 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.

  7. 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...

  8. 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.

  9. 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

  10. 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 ...

  11. Copper (II)

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    ABSTRACT: A Schiff base was prepared from the reaction of 2 - amino - 3 – methylbutanoic acid and 2, 4 - pentanedione. The reaction of the prepared Schiff base with ethanolic solution of copper (II) chloride formed diaquo bis( N – 2 – amino – 3 - methylbutyl - 2, 4 - pentanedionato) copper (II) complex. The Schiff base is ...

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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: ...

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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).

  10. 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 ...

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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 ...

  1. 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.

  2. 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

  3. 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.

  4. 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.

  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. Thermal characterization of nanoporous 'black silicon' surfaces

    Science.gov (United States)

    Nichols, Logan; Duan, Wenqi; Toor, Fatima

    2016-09-01

    In this work we characterize the thermal conductivity properties of nanoprous `black silicon' (bSi). We fabricate the nanoporous bSi using the metal assisted chemical etching (MACE) process utilizing silver (Ag) metal as the etch catalyst. The MACE process steps include (i) electroless deposition of Ag nanoparticles on the Si surface using silver nitrate (AgNO3) and hydrofluoric acid (HF), and (ii) a wet etch in a solution of HF and hydrogen peroxide (H2O2). The resulting porosity of bSi is dependent on the ratio of the concentration of HF to (HF + H2O2); the ratio is denoted as rho (ρ). We find that as etch time of bSi increases the thermal conductivity of Si increases as well. We also analyze the absorption of the bSi samples by measuring the transmission and reflection using IR spectroscopy. This study enables improved understanding of nanoporous bSi surfaces and how they affect the solar cell performance due to the porous structures' thermal properties.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. Development of Solar Grade (SoG) Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, David B; Schmid, Frederick

    2008-01-18

    The rapid growth of the photovoltaics (PV) industry is threatened by the ongoing shortage of suitable solar grade (SoG) silicon. Until 2004, the PV industry relied on the off spec polysilicon from the electronics industry for feedstock. The rapid growth of PV meant that the demand for SoG silicon predictably surpassed this supply. The long-term prospects for PV are very bright as costs have come down, and efficiencies and economies of scale make PV generated electricity ever more competitive with grid electricity. However, the scalability of the current process for producing poly silicon again threatens the future. A less costly, higher volume production technique is needed to supply the long-term growth of the PV industry, and to reduce costs of PV even further. This long-term need was the motivation behind this SBIR proposal. Upgrading metallurgical grade (MG) silicon would fulfill the need for a low-cost, large-scale production. Past attempts to upgrade MG silicon have foundered/failed/had trouble reducing the low segregation coefficient elements, B, P, and Al. Most other elements in MG silicon can be purified very efficiently by directional solidification. Thus, in the Phase I program, Crystal Systems proposed a variety of techniques to reduce B, P, and Al in MG silicon to produce a low cost commercial technique for upgrading MG silicon. Of the variety of techniques tried, vacuum refining and some slagging and additions turned out to be the most promising. These were pursued in the Phase II study. By vacuum refining, the P was reduced from 14 to 0.22 ppmw and the Al was reduced from 370 ppmw to 0.065 ppmw. This process was scaled to 40 kg scale charges, and the results were expressed in terms of half-life, or time to reduce the impurity concentration in half. Best half-lives were 2 hours, typical were 4 hours. Scaling factors were developed to allow prediction of these results to larger scale melts. The vacuum refining required the development of new crucibles

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  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. 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.

  1. 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.)

  2. 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.

  3. 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.)

  4. 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,

  5. 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...

  6. 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...

  7. 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...

  8. Implantation induced extended defects and transient enhanced diffusion in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; Liu, J.; Listebarger, J.; Krishnamoorthy, W.; Zhang, L.; Jones, K.S. [Univ. of Florida, Gainesville, FL (United States)

    1995-08-01

    Transient enhanced diffusion (TED) of dopant in silicon caused by point defects during annealing of implanted. Si has become one of the essential concerns in miniaturization of silicon device technology. In order to control and minimize the TED effect, a fundamental understanding of the evolution of the point defects upon annealing and the interaction between point defects and extended defects and their effects on dopant diffusion is necessary. Our studies were carried out by two parts; (1) For understanding the evolution of <311> and <110> defects, B{sup +} and Si{sup +} implantation at energies (from 5 keV to 40 keV) and doses in the range from 5 x 10{sup 12} to 1 x 10{sup 14}/cm{sup 2} were used. The annealing kinetics were investigated using a N{sub 2} ambient with temperatures for time ranging from 500{degrees}C to 1100{degrees}C for time ranging from 3 min to 3 hours. A matrix of implant energy vs. dose on formation threshold of <311> and <110> defect, interstitials napped and dissolved condition were obtained. (2) For Understanding the interaction between Type II dislocation loop and point defect a B doped buried marker layer was used. The oxidation of silicon surface used as a interstitials injection source and a buried type II loop layer as a point defect detector used to quantify the flux of interstitials injected. Combining the flux measured by loops and dopant diffusion the D{sub I} C{sub I} was determined. The diffusion limited kinetics was concluded. The TED from <311> and EOR (End of Range) <110> defect was studied using 8keV B{sup +} implanted Si to a dose of the le14 and 190keV Ge{sub +} implanted to a dose of le15. Subsequent anneals are done for 5 min and 30 min, respectively, These defects affect dopant diffusion by trapping and releasing point defects.

  9. 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

  10. 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...

  11. 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...

  12. Ni(II), Mn(II), Zn(II)

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Mn(II),. Zn(II) and VO(II) have been synthesised using a Schiff base formed by the condensation of o-phenylenediamine with acetoacetanilide in alcohol medium. All the complexes were characterised on the basis of their microanalytical data, molar.

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. Pb II

    African Journals Online (AJOL)

    Windows User

    used was oven-dried till constant weight and were ground to fine powder in a pestle and mortar. RESULTS AND DISCUSSION. Screening for lead sorption. 15 fungal isolates were screened for Pb(II) biosorption potential at initial pH value of 4.5 and temperature 30°C by incubating freshly harvested wet biomass corres-.

  18. 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...

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Investigation of the impact of mechanical stress on the properties of silicon strip sensors

    CERN Document Server

    Affolder, Tony; The ATLAS collaboration

    2017-01-01

    The new ATLAS tracker for phase II will be composed of silicon pixel and strip sensor modules. The strip sensor module consists of silicon sensors, boards and readout chips. Adhesives are used to connect the modular components thermally and mechanically. It was shown that the silicon sensor is exposed to mechanical stress, due to temperature difference between construction and operation. Mechanical stress can damage the sensor and can change the electrical properties. The thermal induced tensile stress near to the surface of a silicon sensor in a module was simulated and the results are compared to a cooled module. A four point bending setup was used to measure the maximum tensile stress of silicon detectors and to verify the piezoresistive effects on two recent development sensor types used in ATLAS (ATLAS07 and ATLAS12). Changes in the interstrip, bulk and bias resistance and capacitance as well as the coupling capacitance and the implant resistance were measured. The Leakage current was observed to decreas...

  7. 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 ...

  8. 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.

  9. 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.

  10. Silicon Carbide Diodes Performance Characterization and Comparison With Silicon Devices

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Schwarze, Gene E.; Trapp, Scott

    2003-01-01

    Commercially available silicon carbide (SiC) Schottky diodes from different manufacturers were electrically tested and characterized at room temperature. Performed electrical tests include steady state forward and reverse I-V curves, as well as switching transient tests performed with the diodes operating in a hard switch dc-to-dc buck converter. The same tests were performed in current state of the art silicon (Si) and gallium arsenide (GaAs) Schottky and pn junction devices for evaluation and comparison purposes. The SiC devices tested have a voltage rating of 200, 300, and 600 V. The comparison parameters are forward voltage drop at rated current, reverse current at rated voltage and peak reverse recovery currents in the dc to dc converter. Test results show that steady state characteristics of the tested SiC devices are not superior to the best available Si Schottky and ultra fast pn junction devices. Transient tests reveal that the tested SiC Schottky devices exhibit superior transient behavior. This is more evident at the 300 and 600 V rating where SiC Schottky devices showed drastically lower reverse recovery currents than Si ultra fast pn diodes of similar rating.

  11. Epitaxial silicon carbide on a 6″ silicon wafer

    Science.gov (United States)

    Kukushkin, S. A.; Lukyanov, A. V.; Osipov, A. V.; Feoktistov, N. A.

    2014-01-01

    The results of the growth of silicon-carbide films on silicon wafers with a large diameter of 150 mm (6″) by using a new method of solid-phase epitaxy are presented. A SiC film growing on Si wafers was studied by means of spectral ellipsometry, SEM, X-ray diffraction, and Raman scattering. As follows from the studies, SiC layers are epitaxial over the entire surface of a 150-mm wafer. The wafers have no mechanical stresses, are smooth, and do not have bends. The half-width of the X-ray rocking curve (FWHMω- θ) of the wafers varies in the range from 0.7° to 0.8° across the thickness layer of 80-100 nm. The wafers are suitable as templates for the growth of SiC, AlN, GaN, ZnO, and other wide-gap semiconductors on its surface using standard CVD, HVPE, and MBE methods.

  12. Compositional analysis of silicon oxide/silicon nitride thin films

    Directory of Open Access Journals (Sweden)

    Meziani Samir

    2016-06-01

    Full Text Available Hydrogen, amorphous silicon nitride (SiNx:H abbreviated SiNx films were grown on multicrystalline silicon (mc-Si substrate by plasma enhanced chemical vapour deposition (PECVD in parallel configuration using NH3/SiH4 gas mixtures. The mc-Si wafers were taken from the same column of Si cast ingot. After the deposition process, the layers were oxidized (thermal oxidation in dry oxygen ambient environment at 950 °C to get oxide/nitride (ON structure. Secondary ion mass spectroscopy (SIMS, Rutherford backscattering spectroscopy (RBS, Auger electron spectroscopy (AES and energy dispersive X-ray analysis (EDX were employed for analyzing quantitatively the chemical composition and stoichiometry in the oxide-nitride stacked films. The effect of annealing temperature on the chemical composition of ON structure has been investigated. Some species, O, N, Si were redistributed in this structure during the thermal oxidation of SiNx. Indeed, oxygen diffused to the nitride layer into Si2O2N during dry oxidation.

  13. Amorphous Silicon Nanowires Grown on Silicon Oxide Film by Annealing

    Science.gov (United States)

    Yuan, Zhishan; Wang, Chengyong; Chen, Ke; Ni, Zhonghua; Chen, Yunfei

    2017-08-01

    In this paper, amorphous silicon nanowires (α-SiNWs) were synthesized on (100) Si substrate with silicon oxide film by Cu catalyst-driven solid-liquid-solid mechanism (SLS) during annealing process (1080 °C for 30 min under Ar/H2 atmosphere). Micro size Cu pattern fabrication decided whether α-SiNWs can grow or not. Meanwhile, those micro size Cu patterns also controlled the position and density of wires. During the annealing process, Cu pattern reacted with SiO2 to form Cu silicide. More important, a diffusion channel was opened for Si atoms to synthesis α-SiNWs. What is more, the size of α-SiNWs was simply controlled by the annealing time. The length of wire was increased with annealing time. However, the diameter showed the opposite tendency. The room temperature resistivity of the nanowire was about 2.1 × 103 Ω·cm (84 nm diameter and 21 μm length). This simple fabrication method makes application of α-SiNWs become possible.

  14. The Belle Silicon Vertex Detector

    CERN Document Server

    Kawasaki, T

    2002-01-01

    The Belle Silicon Vertex Detector (SVD) started working from June 1999 at the KEK B-factory experiment. The main purpose of the SVD is to make precise measurements of the B decay vertex position, which are essential for the observation of CP asymmetries. Excellent vertex resolution and a good detection efficiency are required for the SVD. In the present paper, the performance of Belle SVD is reviewed. The upgrade plan for the SVD2, which is under construction and will be installed in summer 2002, is also presented.

  15. Untreated silicone breast implant rupture

    DEFF Research Database (Denmark)

    Hölmich, Lisbet R; Vejborg, Ilse M; Conrad, Carsten

    2004-01-01

    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...... that implant rupture is a relatively harmless condition, which only rarely progresses and gives rise to notable symptoms. Even so, because of a small risk of silicone spread, the authors suggest that women with implant ruptures be followed clinically, if not operated on. Because implant ruptures often occur...

  16. Silicon photonics for multicore fiber communication

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld

    2016-01-01

    We review our recent work on silicon photonics for multicore fiber communication, including multicore fiber fan-in/fan-out, multicore fiber switches towards reconfigurable optical add/drop multiplexers. We also present multicore fiber based quantum communication using silicon devices....

  17. Broadband Nonlinear Signal Processing in Silicon Nanowires

    DEFF Research Database (Denmark)

    Yvind, Kresten; Pu, Minhao; Hvam, Jørn Märcher

    The fast non-linearity of silicon allows Tbit/s optical signal processing. By choosing suitable dimensions of silicon nanowires their dispersion can be tailored to ensure a high nonlinearity at power levels low enough to avoid significant two-photon abso We have fabricated low insertion...

  18. Case Report: Magnetically retained silicone facial prosthesis ...

    African Journals Online (AJOL)

    Prosthetic camouflaging of facial defects and use of silicone maxillofacial material are the alternatives to the surgical retreatment. Silicone elastomers provide more options to clinician for customization of the facial prosthesis which is simple, esthetically good when coupled with bio magnets for retention. Key words: Magnet ...

  19. Optical spectroscopy of single silicon nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, Mathias; Steinmetz, David; Becher, Christoph [Fachrichtung 7.3 (Technische Physik), Universitaet des Saarlandes, 66041 Saarbruecken (Germany); Miska, Patrice; Montaigne, F.; Rinnert, Herve; Vergnat, Michel [Laboratoire de Physique des Materiaux - UMR- CNRS 7556, Universite Henri Poincare Nancy I, Faculte des Sciences et Techniques, 54506 Vandoeuvre-les-Nancy (France)

    2007-07-01

    Silicon crystals with sizes of few nanometers embedded in a silica matrix show an improved quantum efficiency for optical emission in comparison with bulk silicon yielding an intense photoluminescence signal in the spectral region around 700-800 nm. This surprising property is attributed to the quantum confinement of excitons in these nanocrystals, also called ''silicon quantum dots''. Such nanostructures are promising candidates for the realization of photonic devices and quantum optics experiments. Although the properties of an ensemble of silicon nanocrystals are well known the optical properties of a single silicon quantum dot are still not well understood. Thus, the investigation of single silicon nanocrystals will contribute to the understanding of their intense photoluminescence. Isolating single silicon nanocrystals would also allow for their employment in quantum optics experiments. Here, we report on the fabrication of silicon nanocrystals with sizes of about 3 nm embedded in thin silica films. The samples show intense luminescence at 770-800 nm depending on fabrication parameters. We discuss the luminescence properties and strategies to experimentally isolate single nanocrystals.

  20. Selecting silicone tubing for device applications.

    Science.gov (United States)

    Jahn, D

    2005-10-01

    A number of factors are involved in selecting the most suitable silicone tubing for a given purpose. These include physical chemistry, performance properties, a supplier's quality system and regulatory compliance. This article provides a guide for device developers when selecting silicone tubing for their applications.

  1. Mechanism of single atom switch on silicon

    DEFF Research Database (Denmark)

    Quaade, Ulrich; Stokbro, Kurt; Thirstrup, C.

    1998-01-01

    We demonstrate single atom switch on silicon which operates by displacement of a hydrogen atom on the silicon (100) surface at room temperature. We find two principal effects by which the switch is controlled: a pronounced maximum of the switching probability as function of sample bias...

  2. Micromachined silicon plates for sensing molecular interactions

    NARCIS (Netherlands)

    Carlen, Edwin; Weinberg, M.S.; Dube, C.E.; Zapata, A.M.; Borenstein, J.T.

    2006-01-01

    A micromachined surface stress sensor based on a thin suspended crystalline silicon circular plate measures differential surface stress changes associated with vapor phase chemisorption of an alkanethiol self-assembled monolayer. The isolated face of the suspended silicon plate serves as the sensing

  3. SOI silicon on glass for optical MEMS

    DEFF Research Database (Denmark)

    Larsen, Kristian Pontoppidan; Ravnkilde, Jan Tue; Hansen, Ole

    2003-01-01

    A newly developed fabrication method for fabrication of single crystalline Si (SCS) components on glass, utilizing Deep Reactive Ion Etching (DRIE) of a Silicon On Insulator (SOI) wafer is presented. The devices are packaged at wafer level in a glass-silicon-glass (GSG) stack by anodic bonding...

  4. Identification of a Mammalian Silicon Transporter

    NARCIS (Netherlands)

    Ratcliffe, Sarah; Jugdaohsingh, Ravin; Ma, Jian Feng; Mitani-Ueno, Nakimi; Vivancos, Julien; Deshmukh, Rupesh; Boekschoten, Mark; Muller, Michael; Mawhinney, Robert; Marron, Alan; Isenring, Paul; Kinrade, Stephen; Bélanger, Richard; Powell, Jonathan

    2017-01-01

    Silicon (Si) has long been known to play a major physiological role in certain organisms, including some sponges and many diatoms and higher plants, leading to the recent identification of multiple proteins responsible for silicon transport in a range of algal and plant species. In mammals, despite

  5. Silicon nanostructures produced by laser direct etching

    DEFF Research Database (Denmark)

    Müllenborn, Matthias; Dirac, Paul Andreas Holger; Petersen, Jon Wulff

    1995-01-01

    A laser direct-write process has been applied to structure silicon on a nanometer scale. In this process, a silicon substrate, placed in a chlorine ambience, is locally heated above its melting point by a continuous-wave laser and translated by high-resolution direct-current motor stages. Only...

  6. Silicon LEDs in FinFET technology

    NARCIS (Netherlands)

    Piccolo, G.; Kuindersma, P.I.; Ragnarsson, L-A.; Hueting, Raymond Josephus Engelbart; Collaert, N.; Schmitz, Jurriaan

    2014-01-01

    We present what to our best knowledge is the first forward operating silicon light-emitting diode (LED) in fin-FET technology. The results show near-infrared (NIR) emission around 1100 nm caused by band-to-band light emission in the silicon which is uniformly distributed across the lowly doped

  7. Improved Jet-Mill Silicon Grinder

    Science.gov (United States)

    Collins, Earl R., Jr.

    1986-01-01

    Proposed refinement in jet-mill grinding of silicon reduces proportion of unusable, overly ground particles. Particles serve as seeds for growth of silicon from vapor. In new grinding apparatus, particle separator distinct from collision chamber. Particle collides only once before sorted for size. If proper size, extracted; if not, returned to chamber for another collision.

  8. Hydroxide catalysis bonding of silicon carbide

    NARCIS (Netherlands)

    Veggel, A.A. van; Ende, D.A. van den; Bogenstahl, J.; Rowan, S.; Cunningham, W.; Gubbels, G.H.M.; Nijmeijer, H.

    2008-01-01

    For bonding silicon carbide optics, which require extreme stability, hydroxide catalysis bonding is considered [Rowan, S., Hough, J. and Elliffe, E., Silicon carbide bonding. UK Patent 040 7953.9, 2004. Please contact Mr. D. Whiteford for further information: D.Whiteford@admin.gla.ac.uk]. This

  9. Simple Approach to Superamphiphobic Overhanging Silicon Nanostructures

    DEFF Research Database (Denmark)

    Kumar, Rajendra; Mogensen, Klaus Bo; Bøggild, Peter

    2010-01-01

    with contact angles up to 152 degrees and roll-off angle down to 8 degrees. Such nonlithographic nanoscale overhanging Structures can also be added to silicon nanograss by deposition of a thin SiO2 layer, which equips the silicon rods with 100-300 nm sized overhanging Structures. This is a simple, fast...

  10. Optical and microstructural investigations of porous silicon

    Indian Academy of Sciences (India)

    Raman scattering and photoluminescence (PL) measurements on (100) oriented -type crystalline silicon (-Si) and porous silicon (PS) samples were carried out. PS samples were prepared by anodic etching of -Si under the illumination of light for different etching times of 30, 60 and 90 min. Raman scattering from the ...

  11. Fabricating solar cells with silicon nanoparticles

    Science.gov (United States)

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

    A laser contact process is employed to form contact holes to emitters of a solar cell. Doped silicon nanoparticles are formed over a substrate of the solar cell. The surface of individual or clusters of silicon nanoparticles is coated with a nanoparticle passivation film. Contact holes to emitters of the solar cell are formed by impinging a laser beam on the passivated silicon nanoparticles. For example, the laser contact process may be a laser ablation process. In that case, the emitters may be formed by diffusing dopants from the silicon nanoparticles prior to forming the contact holes to the emitters. As another example, the laser contact process may be a laser melting process whereby portions of the silicon nanoparticles are melted to form the emitters and contact holes to the emitters.

  12. Hysteroscopic tubal occlusion with silicone rubber.

    Science.gov (United States)

    Reed, T P; Erb, R

    1983-03-01

    A new method of sterilization for women is being investigated in several outpatient centers. The technique involves flowing liquid silicone rubber into the fallopian tubes. The silicone cures in place and forms a rubbery solid plug. The catalyzed liquid silicone is pumped through a special polysulfone guide assembly that fits through the operating channel of a standard hysteroscope. On the end of the guide is a hollow premolded silicone rubber tip that fits into the cornual ostium of the tube. When the silicone cures it also cross-links to this tip so that the tip becomes part of the plug. Results as of April 1, 1982, from 350 women in the Philadelphia center suggest that proper plug formation prevents pregnancy and that the method can be applied to about 85% of properly selected women.

  13. Silicon photonics and challenges for fabrication

    Science.gov (United States)

    Feilchenfeld, N. B.; Nummy, K.; Barwicz, T.; Gill, D.; Kiewra, E.; Leidy, R.; Orcutt, J. S.; Rosenberg, J.; Stricker, A. D.; Whiting, C.; Ayala, J.; Cucci, B.; Dang, D.; Doan, T.; Ghosal, M.; Khater, M.; McLean, K.; Porth, B.; Sowinski, Z.; Willets, C.; Xiong, C.; Yu, C.; Yum, S.; Giewont, K.; Green, W. M. J.

    2017-03-01

    Silicon photonics is rapidly becoming the key enabler for meeting the future data speed and volume required by the Internet of Things. A stable manufacturing process is needed to deliver cost and yield expectations to the technology marketplace. We present the key challenges and technical results from both 200mm and 300mm facilities for a silicon photonics fabrication process which includes monolithic integration with CMOS. This includes waveguide patterning, optical proximity correction for photonic devices, silicon thickness uniformity and thick material patterning for passive fiber to waveguide alignment. The device and process metrics show that the transfer of the silicon photonics process from 200mm to 300mm will provide a stable high volume manufacturing platform for silicon photonics designs.

  14. Silicon quantum dots for biological applications.

    Science.gov (United States)

    Chinnathambi, Shanmugavel; Chen, Song; Ganesan, Singaravelu; Hanagata, Nobutaka

    2014-01-01

    Semiconductor nanoparticles (or quantum dots, QDs) exhibit unique optical and electronic properties such as size-controlled fluorescence, high quantum yields, and stability against photobleaching. These properties allow QDs to be used as optical labels for multiplexed imaging and in drug delivery detection systems. Luminescent silicon QDs and surface-modified silicon QDs have also been developed as potential minimally toxic fluorescent probes for bioapplications. Silicon, a well-known power electronic semiconductor material, is considered an extremely biocompatible material, in particular with respect to blood. This review article summarizes existing knowledge related to and recent research progress made in the methods for synthesizing silicon QDs, as well as their optical properties and surface-modification processes. In addition, drug delivery systems and in vitro and in vivo imaging applications that use silicon QDs are also discussed. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. 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.

  16. Roll up nanowire battery from silicon chips.

    Science.gov (United States)

    Vlad, Alexandru; Reddy, Arava Leela Mohana; Ajayan, Anakha; Singh, Neelam; Gohy, Jean-François; Melinte, Sorin; Ajayan, Pulickel M

    2012-09-18

    Here we report an approach to roll out Li-ion battery components from silicon chips by a continuous and repeatable etch-infiltrate-peel cycle. Vertically aligned silicon nanowires etched from recycled silicon wafers are captured in a polymer matrix that operates as Li(+) gel-electrolyte and electrode separator and peeled off to make multiple battery devices out of a single wafer. Porous, electrically interconnected copper nanoshells are conformally deposited around the silicon nanowires to stabilize the electrodes over extended cycles and provide efficient current collection. Using the above developed process we demonstrate an operational full cell 3.4 V lithium-polymer silicon nanowire (LIPOSIL) battery which is mechanically flexible and scalable to large dimensions.

  17. Micromachined silicon seismic accelerometer development

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Montague, S. [and others

    1996-08-01

    Batch-fabricated silicon seismic transducers could revolutionize the discipline of seismic monitoring by providing inexpensive, easily deployable sensor arrays. Our ultimate goal is to fabricate seismic sensors with sensitivity and noise performance comparable to short-period seismometers in common use. We expect several phases of development will be required to accomplish that level of performance. Traditional silicon micromachining techniques are not ideally suited to the simultaneous fabrication of a large proof mass and soft suspension, such as one needs to achieve the extreme sensitivities required for seismic measurements. We have therefore developed a novel {open_quotes}mold{close_quotes} micromachining technology that promises to make larger proof masses (in the 1-10 mg range) possible. We have successfully integrated this micromolding capability with our surface-micromachining process, which enables the formation of soft suspension springs. Our calculations indicate that devices made in this new integrated technology will resolve down to at least sub-{mu}G signals, and may even approach the 10{sup -10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

  18. Vacuum silicon photomultipliers: Recent developments

    Energy Technology Data Exchange (ETDEWEB)

    Barbarino, Giancarlo [Dipartimento Scienze Fisiche, Università “Federico II” Napoli (Italy); INFN Napoli (Italy); Barbato, Felicia Carla Tiziana [INFN Napoli (Italy); Campajola, Luigi [Dipartimento Scienze Fisiche, Università “Federico II” Napoli (Italy); Asmundis, Riccardo de [INFN Napoli (Italy); De Rosa, Gianfranca [Dipartimento Scienze Fisiche, Università “Federico II” Napoli (Italy); Mollo, Carlos Maximiliano [INFN Napoli (Italy); Vivolo, Daniele, E-mail: vivolo@na.infn.it [Dipartimento Scienze Fisiche, Università “Federico II” Napoli (Italy); INFN Napoli (Italy)

    2013-08-01

    VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an innovative design for a modern hybrid, high gain, silicon based photodetector based on the combination of a SiPM with a hemispherical vacuum glass PMT standard envelope. In such a device photoelectrons emitted by the photocathode are accelerated and focused by an electric field towards a small focal area covered by the SiPM which therefore acts as an amplifier, thus substituting the classical dynode chain of a PMT. With a view to the realization of a first prototype of VSiPMT our group is carrying out a preliminary work aimed at the study of SiPM performances as an electron detector, including an accurate Geant4-based simulation of the interaction between SiPM and electron beams. In order to perform a full characterization of the SiPM we developed an experimental setup for the extraction and the acceleration of a beam of backward secondary electrons emitted after the bombardment of a carbon foil by a proton beam extracted in a TTT-3 accelerator.

  19. Silicon transporters in higher plants.

    Science.gov (United States)

    Ma, Jian Feng

    2010-01-01

    Silicon (Si) is the second most abundant element in the Earth's crust and exerts beneficial effects on plant growth and production by alleviating both biotic and abiotic stresses including diseases, pests, lodging, drought and nutrient imbalance. Silicon is taken up by the roots in the form ofsilicic acid, a noncharged molecule. Recently both influx (Lsil) and efflux (Lsi2) transporters for silicic acid have been identified in gramineous plants including rice, barley and maize. Lsil and its homologs are influx Si transporters, which belong to a Nod26-like major intrinsic protein (NIP) subfamily in the aquaporin protein family. They are responsible for the transport of Si from the external solution to the root cells. On the other hand, Lsi2 and its homologs are efflux Si transporters, belonging to putative anion transporters and are responsible for the transport of Si out of the cells toward the xylem. All influx transporters show polar localization at the distal side. Among efflux transporters, Lsi2 in rice shows polar localization at the proximal side, but that in barley and maize does not show polar localization. The cell-specificity of localization of Si transporters and expression patterns are different between species. Rice Si transporters are also permeable to arsenite.

  20. Phonon conduction in silicon nanobeams

    Science.gov (United States)

    Park, Woosung; Shin, Dongsuk D.; Kim, Soo Jin; Katz, Joseph S.; Park, Joonsuk; Ahn, Chae Hyuck; Kodama, Takashi; Asheghi, Mehdi; Kenny, Thomas W.; Goodson, Kenneth E.

    2017-05-01

    Despite extensive studies on thermal transport in thin silicon films, there has been little work studying the thermal conductivity of single-crystal rectangular, cross-sectional nanobeams that are commonly used in many applications such as nanoelectronics (FinFETs), nano-electromechanical systems, and nanophotonics. Here, we report experimental data on the thermal conductivity of silicon nanobeams of a thickness of ˜78 nm and widths of ˜65 nm, 170 nm, 270 nm, 470 nm, and 970 nm. The experimental data agree well (within ˜9%) with the predictions of a thermal conductivity model that uses a combination of bulk mean free paths obtained from ab initio calculations and a suppression function derived from the kinetic theory. This work quantifies the impact of nanobeam aspect ratios on thermal transport and establishes a criterion to differentiate between thin films and beams in studying thermal transport. The thermal conductivity of a 78 nm × 65 nm nanobeam is ˜32 W m-1 K-1, which is roughly a factor of two smaller than that of a 78 nm thick film.

  1. 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.

  2. Ni(II), Cu(II) and Zn(II)

    African Journals Online (AJOL)

    Chemical speciation of citric acid complexes of Co(II), Ni(II), Cu(II) and Zn(II) was investigated pH-metrically in 0.0-2.5% anionic, cationic and neutral micellar media. The primary alkalimetric data were pruned with SCPHD program. The existence of different binary species was established from modeling studies using the ...

  3. Ni(II), Cu(II) and Zn(II)

    African Journals Online (AJOL)

    NICO

    2010-06-15

    Jun 15, 2010 ... physico-chemical techniques. A square planar geometry was suggested for Cu(II) and octahedral geometry proposed for Co(II),. Ni(II) and Zn(II). TG curves indicated that the complexes decompose in three to four steps. The presence of coordinated water in metal complexes was confirmed by thermal and ...

  4. Low cost silicon solar array project large area silicon sheet task: Silicon web process development

    Science.gov (United States)

    Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Blais, P. D.; Davis, J. R., Jr.

    1977-01-01

    Growth configurations were developed which produced crystals having low residual stress levels. The properties of a 106 mm diameter round crucible were evaluated and it was found that this design had greatly enhanced temperature fluctuations arising from convection in the melt. Thermal modeling efforts were directed to developing finite element models of the 106 mm round crucible and an elongated susceptor/crucible configuration. Also, the thermal model for the heat loss modes from the dendritic web was examined for guidance in reducing the thermal stress in the web. An economic analysis was prepared to evaluate the silicon web process in relation to price goals.

  5. Environmental testing of Block II solar cell modules. Low-Cost Solar Array Project

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, J.S.

    1979-01-01

    The results of environmental tests of Block II solar modules are described. Block II was the second large scale procurement of silicon solar cell modules made by the JPL Low-Cost Solar Array Project with deliveries in 1977 and early 1978. The results of testing showed that the Block II modules were greatly improved over Block I modules. In several cases it was shown that design improvements were needed to reduce environmental test degradation. These improvements were incorporated during this production run.

  6. Hysteroscopic sterilization: silicone elastic plugs.

    Science.gov (United States)

    Reed, T P

    1983-06-01

    Erb, Davis, and Kyriazis developed the application of the silicone rubber plug directly into the cornual openings of the fallopian tubes in rabbits by working through hysterotomies. Subsequently, does were exposed to bucks for periods up to 280 days, and none of the does became pregnant. Tissue sections of some tubes were studied microscopically, and no pathological findings were found. The only finding was the flattening of the cilia. This work continued through the early 1970s at Franklin Research Center and Hahnemann Medical College in Philadelphia. 2 basic concepts were developed: 1) there was direct application of catalyzed silicone rubber into the cornual ostium, and 2) the molded obturator (cornual) tip became part of the plug. The technique's success depends on the fact that silicone rubber cures (becomes a rubbery solid) in about 5 minutes without heat or chemical reaction. The formed-in-place plug is made possible because the silicone rubber in curing will cross-link to itself only with the result that the obturator tip at the cornu cross-links and becomes part of the formed-in-place plug. The procedure, as performed in humans, is outlined in detail and is diagrammed. A single hinged bivalve speculum exposes the cervix so that after the hysteroscope is inserted through the cervix into the uterine cavity, the speculum can be removed. The procedure should be performed early in the proliferative phase of the cycle, for generally visualization is better at this time because the endometrium is thinner and less vascular and succulent. Once the ostia have been identified, the aspirator is removed from the cavity. The guide assembly with its attached obturator tip is introduced through the opening channel of the scope into the uterine cavity. Once bilateral good push tests have been obtained, the assistant adds catalyst (stanous octuate) to the silicone in the nonairentraining mixer and dispenser that has been taken from the freezer. Once curing is complete, the

  7. VLSI (Very Large Scale Integrated Circuits) Design with the MacPitts Silicon Compiler.

    Science.gov (United States)

    1985-09-01

    fulfillment of the (. requirements for the degree of MASTER OF SCIENCE IN ELECTRICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL September 1985... Electrical and Computer Engineering So ’ohfn7N. Dyer, Dean of Science and Engineering V0 ABSTRACT An analysis of the MacPitts silicon compiler is presented...size, and power comsumption . 4 K: Ui Ii Chapter VI is a design example. A design cycle for MacPitts is developed, and illustrated with the Hamming 15/4

  8. Nanostructured silicon particles for medical applications.

    Science.gov (United States)

    Kleps, Irina; Ignat, Teodora; Miu, Mihaela; Craciunoiu, Florea; Trif, Mihaela; Simion, Monica; Bragaru, Adina; Dinescu, Adrian

    2010-04-01

    Porous silicon (PS) which has different properties from the bulk material due to the quantum confinement effects is beside other physical properties (e.g., light emitting) bioactive or even bioresorbable. The aim of this paper is to optimise the experimental conditions for the fabrication of nanostructured Si particles and to find the best methods for attaching on its surface molecules of therapeutic interest. The selective porosification has been performed using (i) a dielectric/metallic masking layer micropatterned with corresponding etching windows; (ii) a controlled diffusion process leading to n-type islands into p-type Si substrate. The PS particles were detached from the Si substrate by switching the electrochemical etching conditions from porosification towards the electropolishing regime. Also, similar results were obtained by fabrication of PS multilayer structures subjected to an additional ultrasonation process. Different organic molecules with antitumoral effect, such as chondroitin sulphate (a sulphated glycosaminoglycan), lactoferrin (globular protein with antimicrobial activity) and N-butyldeoxynojirimycin (an imino sugar that inhibits the growth of the CT-2A brain tumour) were covalently attached on the PS particle surface using 3-aminopropyltriethoxysilane (APTS) molecule as linker. Furthermore, to complete the administration/therapy of drugs, for microparticle targeting and imaging, Fe3O4 nanoparticles were integrated in PS matrix by co-precipitation from a solution of iron salts (Fe3+/Fe2+) in alkaline medium. Microscopic and spectroscopic analyses have been used to characterize the Si microparticles. Tumoral cells were cultivated on the nanostructured PS particles and a significant decrease of the cells density was observed on all investigated samples comparatively with the blank substrate without antitumoral molecules.

  9. 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.

  10. Argus II retinal prosthesis implantation with scleral flap and autogenous temporalis fascia as alternative patch graft material: a 4-year follow-up

    National Research Council Canada - National Science Library

    Matet, Alexandre; Amar, Nawel; Mohand-Said, Saddek; Sahel, José-Alain; Barale, Pierre-Olivier

    2016-01-01

    The Argus II retinal prosthesis is composed of an epiretinal electrode array positioned over the macula and connected to an extrascleral electronics case via a silicone cable, running through a sclerotomy...

  11. The mid-IR silicon photonics sensor platform (Conference Presentation)

    Science.gov (United States)

    Kimerling, Lionel; Hu, Juejun; Agarwal, Anuradha M.

    2017-02-01

    Advances in integrated silicon photonics are enabling highly connected sensor networks that offer sensitivity, selectivity and pattern recognition. Cost, performance and the evolution path of the so-called `Internet of Things' will gate the proliferation of these networks. The wavelength spectral range of 3-8um, commonly known as the mid-IR, is critical to specificity for sensors that identify materials by detection of local vibrational modes, reflectivity and thermal emission. For ubiquitous sensing applications in this regime, the sensors must move from premium to commodity level manufacturing volumes and cost. Scaling performance/cost is critically dependent on establishing a minimum set of platform attributes for point, wearable, and physical sensing. Optical sensors are ideal for non-invasive applications. Optical sensor device physics involves evanescent or intra-cavity structures for applied to concentration, interrogation and photo-catalysis functions. The ultimate utility of a platform is dependent on sample delivery/presentation modalities; system reset, recalibration and maintenance capabilities; and sensitivity and selectivity performance. The attributes and performance of a unified Glass-on-Silicon platform has shown good prospects for heterogeneous integration on materials and devices using a low cost process flow. Integrated, single mode, silicon photonic platforms offer significant performance and cost advantages, but they require discovery and qualification of new materials and process integration schemes for the mid-IR. Waveguide integrated light sources based on rare earth dopants and Ge-pumped frequency combs have promise. Optical resonators and waveguide spirals can enhance sensitivity. PbTe materials are among the best choices for a standard, waveguide integrated photodetector. Chalcogenide glasses are capable of transmitting mid-IR signals with high transparency. Integrated sensor case studies of i) high sensitivity analyte detection in

  12. Lifetime of Nano-Structured Black Silicon for Photovoltaic Applications

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym; Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk

    2016-01-01

    In this work, we present recent results of lifetime optimization for nano-structured black silicon and its photovoltaic applications. Black silicon nano-structures provide significant reduction of silicon surface reflection due to highly corrugated nanostructures with excellent light trapping......, respectively. This is promising for use of black silicon RIE nano-structuring in a solar cell process flow...

  13. Effect of zafirlukast on capsular contracture around silicone implants in rats Efeito do zafirlukast na contratura capsular ao redor de implantes de silicone em ratos

    Directory of Open Access Journals (Sweden)

    Érika Malheiros Bastos

    2012-01-01

    Full Text Available PURPOSE: To evaluate the effect of zafirlukast on capsular contracture around silicone implants by measuring the pressure within the implant, using a rat experimental model. METHODS: Forty adult female Wistar rats were used. Each one received two silicone implants, one with smooth-surface and the other with textured-surface. They were randomly divided into four groups (n=10. The rats of control group I were sacrificed after the implants. The remaining animals were subjected to a daily regimen of intra-peritoneal injection for a period of 90 days and they were distributed as follows: control group II received 0.9% physiological saline solution; experimental group I received zafirlukast 1.25 mg/kg; and experimental group II received zafirlukast 5 mg/kg. The measurement of intra-implant pressure of control group I was determined on the surgery day and in other groups on the ninetieth day, after being sacrificed. RESULTS: In the evaluation of textured implants there was an increase of internal pressure in the control group II, and there was no increase in the experimental groups. Compared to the controls there were not significant differences in smooth implants. CONCLUSION: Zafirlukast reduced the risk of developing capsular contracture around silicone implants with textured surface.OBJETIVO: Avaliar o efeito do zafirlukast na contratura capsular ao redor de implantes de silicone, através da aferição da pressão intra-implante, utilizando-se um modelo experimental de ratos. MÉTODOS: Quarenta ratos fêmeas Wistar foram utilizados. Cada um recebeu dois implantes de silicone, sendo um com superfície lisa e outro texturizada. Foram divididos aleatoriamente em quatro grupos (n=10. Os ratos do grupo controle I foram sacrificados após o implante. O restante dos animais foi submetido a um regime diário de injeção intraperitoneal por um período de 90 dias e foram distribuídos: grupo controle II recebeu solução salina fisiológica 0,9%, grupo

  14. Fusion bonding of silicon nitride surfaces

    DEFF Research Database (Denmark)

    Reck, Kasper; Østergaard, Christian; Thomsen, Erik Vilain

    2011-01-01

    results on bonding of thin and thick Si3N4 layers. The new results include high temperature bonding without any pretreatment, along with improved bonding ability achieved by thermal oxidation and chemical pretreatment. The bonded wafers include both unprocessed and processed wafers with a total silicon......While silicon nitride surfaces are widely used in many micro electrical mechanical system devices, e.g. for chemical passivation, electrical isolation or environmental protection, studies on fusion bonding of two silicon nitride surfaces (Si3N4–Si3N4 bonding) are very few and highly application...... specific. Often fusion bonding of silicon nitride surfaces to silicon or silicon dioxide to silicon surfaces is preferred, though Si3N4–Si3N4 bonding is indeed possible and practical for many devices as will be shown in this paper. We present an overview of existing knowledge on Si3N4–Si3N4 bonding and new...

  15. Silicon Micro- and Nanofabrication for Medicine

    Science.gov (United States)

    Fine, Daniel; Goodall, Randy; Bansal, Shyam S.; Chiappini, Ciro; Hosali, Sharath; van de Ven, Anne L.; Srinivasan, Srimeenkashi; Liu, Xuewu; Godin, Biana; Brousseau, Louis; Yazdi, Iman K.; Fernandez-Moure, Joseph; Tasciotti, Ennio; Wu, Hung-Jen; Hu, Ye; Klemm, Steve; Ferrari, Mauro

    2013-01-01

    This manuscript constitutes a review of several innovative biomedical technologies fabricated using the precision and accuracy of silicon micro- and nanofabrication. The technologies to be reviewed are subcutaneous nanochannel drug delivery implants for the continuous tunable zero-order release of therapeutics, multi-stage logic embedded vectors for the targeted systemic distribution of both therapeutic and imaging contrast agents, silicon and porous silicon nanowires for investigating cellular interactions and processes as well as for molecular and drug delivery applications, porous silicon (pSi) as inclusions into biocomposites for tissue engineering, especially as it applies to bone repair and regrowth, and porous silica chips for proteomic profiling. In the case of the biocomposites, the specifically designed pSi inclusions not only add to the structural robustness, but can also promote tissue and bone regrowth, fight infection, and reduce pain by releasing stimulating factors and other therapeutic agents stored within their porous network. The common material thread throughout all of these constructs, silicon and its associated dielectrics (silicon dioxide, silicon nitride, etc.), can be precisely and accurately machined using the same scalable micro- and nanofabrication protocols that are ubiquitous within the semiconductor industry. These techniques lend themselves to the high throughput production of exquisitely defined and monodispersed nanoscale features that should eliminate architectural randomness as a source of experimental variation thereby potentially leading to more rapid clinical translation. PMID:23584841

  16. 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.

  17. Porous silicon technology for integrated microsystems

    Science.gov (United States)

    Wallner, Jin Zheng

    With the development of micro systems, there is an increasing demand for integrable porous materials. In addition to those conventional applications, such as filtration, wicking, and insulating, many new micro devices, including micro reactors, sensors, actuators, and optical components, can benefit from porous materials. Conventional porous materials, such as ceramics and polymers, however, cannot meet the challenges posed by micro systems, due to their incompatibility with standard micro-fabrication processes. In an effort to produce porous materials that can be used in micro systems, porous silicon (PS) generated by anodization of single crystalline silicon has been investigated. In this work, the PS formation process has been extensively studied and characterized as a function of substrate type, crystal orientation, doping concentration, current density and surfactant concentration and type. Anodization conditions have been optimized for producing very thick porous silicon layers with uniform pore size, and for obtaining ideal pore morphologies. Three different types of porous silicon materials: meso porous silicon, macro porous silicon with straight pores, and macro porous silicon with tortuous pores, have been successfully produced. Regular pore arrays with controllable pore size in the range of 2mum to 6mum have been demonstrated as well. Localized PS formation has been achieved by using oxide/nitride/polysilicon stack as masking materials, which can withstand anodization in hydrofluoric acid up to twenty hours. A special etching cell with electrolytic liquid backside contact along with two process flows has been developed to enable the fabrication of thick macro porous silicon membranes with though wafer pores. For device assembly, Si-Au and In-Au bonding technologies have been developed. Very low bonding temperature (˜200°C) and thick/soft bonding layers (˜6mum) have been achieved by In-Au bonding technology, which is able to compensate the potentially

  18. Silicon Heterojunction System Field Performance

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Dirk C.; Deline, Chris; Johnston, Steve; Rummel, Steve R.; Sekulic, Bill; Hacke, Peter; Kurtz, Sarah R.; Davis, Kristopher O.; Schneller, Eric John; Sun, Xingshu; Alam, Muhammad A.; Sinton, Ronald A.

    2017-11-17

    A silicon heterostructure photovoltaic system fielded for 10 years has been investigated in detail. The system has shown degradation, but at a rate similar to an average Si system, and still within the module warranty level. The power decline is dominated by a nonlinear Voc loss rather than more typical changes in Isc or Fill Factor. Modules have been evaluated using multiple techniques including: dark and light I-V measurement, Suns-Voc, thermal imaging, and quantitative electroluminescence. All techniques indicate that recombination and series resistance in the cells have increased along with a decrease of factor 2 in minority carrier lifetime. Performance changes are fairly uniform across the module, indicating changes occur primarily within the cells.

  19. Germanium silicon physics and materials

    CERN Document Server

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

    1998-01-01

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

  20. Silicon in plant disease control

    Directory of Open Access Journals (Sweden)

    Edson Ampélio Pozza

    2015-06-01

    Full Text Available All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

  1. Silicon nanomembranes for fingertip electronics

    Science.gov (United States)

    Ying, Ming; Bonifas, Andrew P.; Lu, Nanshu; Su, Yewang; Li, Rui; Cheng, Huanyu; Ameen, Abid; Huang, Yonggang; Rogers, John A.

    2012-08-01

    We describe the use of semiconductor nanomaterials, advanced fabrication methods and unusual device designs for a class of electronics capable of integration onto the inner and outer surfaces of thin, elastomeric sheets in closed-tube geometries, specially formed for mounting on the fingertips. Multifunctional systems of this type allow electrotactile stimulation with electrode arrays multiplexed using silicon nanomembrane (Si NM) diodes, high-sensitivity strain monitoring with Si NM gauges, and tactile sensing with elastomeric capacitors. Analytical calculations and finite element modeling of the mechanics quantitatively capture the key behaviors during fabrication/assembly, mounting and use. The results provide design guidelines that highlight the importance of the NM geometry in achieving the required mechanical properties. This type of technology could be used in applications ranging from human-machine interfaces to ‘instrumented’ surgical gloves and many others.

  2. Schematic driven silicon photonics design

    Science.gov (United States)

    Chrostowski, Lukas; Lu, Zeqin; Flückiger, Jonas; Pond, James; Klein, Jackson; Wang, Xu; Li, Sarah; Tai, Wei; Hsu, En Yao; Kim, Chan; Ferguson, John; Cone, Chris

    2016-03-01

    Electronic circuit designers commonly start their design process with a schematic, namely an abstract representation of the physical circuit. In integrated photonics on the other hand, it is very common for the design to begin at the physical component level. In order to build large integrated photonic systems, it is crucial to design using a schematic-driven approach. This includes simulations based on schematics, schematic-driven layout, layout versus schematic verification, and post-layout simulations. This paper describes such a design framework implemented using Mentor Graphics and Lumerical Solutions design tools. In addition, we describe challenges in silicon photonics related to manufacturing, and how these can be taken into account in simulations and how these impact circuit performance.

  3. Visualizing a silicon quantum computer

    Science.gov (United States)

    Sanders, Barry C.; Hollenberg, Lloyd C. L.; Edmundson, Darran; Edmundson, Andrew

    2008-12-01

    Quantum computation is a fast-growing, multi-disciplinary research field. The purpose of a quantum computer is to execute quantum algorithms that efficiently solve computational problems intractable within the existing paradigm of 'classical' computing built on bits and Boolean gates. While collaboration between computer scientists, physicists, chemists, engineers, mathematicians and others is essential to the project's success, traditional disciplinary boundaries can hinder progress and make communicating the aims of quantum computing and future technologies difficult. We have developed a four minute animation as a tool for representing, understanding and communicating a silicon-based solid-state quantum computer to a variety of audiences, either as a stand-alone animation to be used by expert presenters or embedded into a longer movie as short animated sequences. The paper includes a generally applicable recipe for successful scientific animation production.

  4. Bimodal condensation silicone elastomers as dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Madsen, Frederikke Bahrt; Skov, Anne Ladegaard

    unimodal refers to that there is one polymer only in the system. As an alternative to unimodal networks there are the bimodal networks where two polymers with significantly different molecular weights are mixed with one crosslinker. [2]Silicone rubber can be divided into condensation type and addition type...... according to the curing reaction. The advantages of condensation silicones compared to addition are the relatively low cost, the curing rate largely being independent of temperature, the excellent adhesion, and the catalyst being nontoxic. [3]In this work, a series of bimodal condensation silicone...

  5. Quantum conductance in silicon quantum wires

    CERN Document Server

    Bagraev, N T; Klyachkin, L E; Malyarenko, A M; Gehlhoff, W; Ivanov, V K; Shelykh, I A

    2002-01-01

    The results of investigations of electron and hole quantum conductance staircase in silicon quantum wires are presented. The characteristics of self-ordering quantum wells of n- and p-types, which from on the silicon (100) surface in the nonequilibrium boron diffusion process, are analyzed. The results of investigations of the quantum conductance as the function of temperature, carrier concentration and modulation degree of silicon quantum wires are given. It is found out, that the quantum conductance of the one-dimensional channels is observed, for the first time, at an elevated temperature (T >= 77 K)

  6. Silicon photonics III systems and applications

    CERN Document Server

    Lockwood, David

    2016-01-01

    This book is volume III of a series of books on silicon photonics. It reports on the development of fully integrated systems where many different photonics component are integrated together to build complex circuits. This is the demonstration of the fully potentiality of silicon photonics. It contains a number of chapters written by engineers and scientists of the main companies, research centers and universities active in the field. It can be of use for all those persons interested to know the potentialities and the recent applications of silicon photonics both in microelectronics, telecommunication and consumer electronics market.

  7. Silicon compounds in the Jupiter atmosphere

    Science.gov (United States)

    Howland, G.; Harteck, P.; Reeves, R. R., Jr.

    1979-01-01

    The formation of colored silicon compounds under nonequilibrium conditions is discussed with reference to the composition of the Jupiter atmosphere. It is shown that many of these reactions produce strongly colored intermediates that are relatively stable and similar in appearance to those observed on Jupiter. It is suggested that the silicon compounds could substantially contribute to the colors observed on Jupiter. The colored intermediates may be the result of relatively rapid amorphous silicon monoxide formation in vertical atmospheric currents in the region near the red spot and in the red spot itself.

  8. Titanium catalyzed silicon nanowires and nanoplatelets

    Directory of Open Access Journals (Sweden)

    Mohammad A. U. Usman

    2013-03-01

    Full Text Available Silicon nanowires, nanoplatelets, and other morphologies resulted from silicon growth catalyzed by thin titanium layers. The nanowires have diameters down to 5 nm and lengths to tens of micrometers. The two-dimensional platelets, in some instances with filigreed, snow flake-like shapes, had thicknesses down to the 10 nm scale and spans to several micrometers. These platelets grew in a narrow temperature range around 900 celsius, apparently representing a new silicon crystallite morphology at this length scale. We surmise that the platelets grow with a faceted dendritic mechanism known for larger crystals nucleated by titanium silicide catalyst islands.

  9. Fluidized-Bed Cleaning of Silicon Particles

    Science.gov (United States)

    Rohatgi, Naresh K.; Hsu, George C.

    1987-01-01

    Fluidized-bed chemical cleaning process developed to remove metallic impurities from small silicon particles. Particles (250 micrometer in size) utilized as seed material in silane pyrolysis process for production of 1-mm-size silicon. Product silicon (1 mm in size) used as raw material for fabrication of solar cells and other semiconductor devices. Principal cleaning step is wash in mixture of hydrochloric and nitric acids, leaching out metals and carrying them away as soluble chlorides. Particles fluidized by cleaning solution to assure good mixing and uniform wetting.

  10. Bond Testing for Effects of Silicone Contamination

    Science.gov (United States)

    Plaia, James; Evans, Kurt

    2005-01-01

    In 2003 ATK Thiokol discovered that the smocks and coveralls worn by its operations personnel for safety and contamination control were themselves contaminated with a silicone defoamer and a silicone oil. As a growing list of items have been identified as having this form of contamination, it was desirable to devise a test method to determine if the contamination level detected could cause subsequent processing concerns. The smocks and coveralls could potentially contact bonding surfaces during processing so the test method focused on dry transfer of the silicone from the clothing to the bonding surface.

  11. Calibration and alignment of the CMS silicon tracking detector

    Energy Technology Data Exchange (ETDEWEB)

    Stoye, M.

    2007-07-15

    The Large Hadron Collider (LHC) will dominate the high energy physics program in the coming decade. The discovery of the standard model Higgs boson and the discovery of super-symmetric particles are within the reach at the energy scale explored by the LHC. However, the high luminosity and the high energy of the colliding protons lead to challenging demands on the detectors. The hostile radiation environment requires irradiation hard detectors, where the innermost subdetectors, consisting of silicon modules, are most affected. This thesis is devoted to the calibration and alignment of the silicon tracking detector. Electron test beam data, taken at DESY, have been used to investigate the performance of detector modules which previously were irradiated with protons up to a dose expected after 10 years of operation. The irradiated sensors turned out to be still better than required. The performance of the inner tracking systems will be dominated by the degree to which the positions of the sensors can be determined. Only a track based alignment procedure can reach the required precision. Such an alignment procedure is a major challenge given that about 50000 geometry constants need to be measured. Making use of the novel {chi}{sup 2} minimization program Millepede II an alignment strategy has been developed in which all detector components are aligned simultaneously, as many sources of information as possible are used, and all correlations between the position parameters of the detectors are taken into account. Utilizing simulated data, a proof of concept of the alignment strategy is shown. (orig.)

  12. Strip defect recognition in electrical tests of silicon microstrip sensors

    Energy Technology Data Exchange (ETDEWEB)

    Valentan, Manfred, E-mail: valentan@mpp.mpg.de

    2017-02-11

    This contribution describes the measurement procedure and data analysis of AC-coupled double-sided silicon microstrip sensors with polysilicon resistor biasing. The most thorough test of a strip sensor is an electrical measurement of all strips of the sensor; the measured observables include e.g. the strip's current and the coupling capacitance. These measurements are performed to find defective strips, e.g. broken capacitors (pinholes) or implant shorts between two adjacent strips. When a strip has a defect, its observables will show a deviation from the “typical value”. To recognize and quantify certain defects, it is necessary to determine these typical values, i.e. the values the observables would have without the defect. As a novel approach, local least-median-of-squares linear fits are applied to determine these “would-be” values of the observables. A least-median-of-squares fit is robust against outliers, i.e. it ignores the observable values of defective strips. Knowing the typical values allows to recognize, distinguish and quantify a whole range of strip defects. This contribution explains how the various defects appear in the data and in which order the defects can be recognized. The method has been used to find strip defects on 30 double-sided trapezoidal microstrip sensors for the Belle II Silicon Vertex Detector, which have been measured at the Institute of High Energy Physics, Vienna (Austria).

  13. Fabrication of thick silicon nitride blocks embedded in low-resistivity silicon substrates for radio frequency applications

    NARCIS (Netherlands)

    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.

  14. A beam monitor using silicon pixel sensors for hadron therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhen, E-mail: zwang@mails.ccnu.edu.cn; Zou, Shuguang; Fan, Yan; Liu, Jun; Sun, Xiangming, E-mail: sphy2007@126.com; Wang, Dong; Kang, Huili; Sun, Daming; Yang, Ping; Pei, Hua; Huang, Guangming; Xu, Nu; Gao, Chaosong; Xiao, Le

    2017-03-21

    We report the design and test results of a beam monitor developed for online monitoring in hadron therapy. The beam monitor uses eight silicon pixel sensors, Topmetal-II{sup -}, as the anode array. Topmetal-II{sup -} is a charge sensor designed in a CMOS 0.35 µm technology. Each Topmetal-II{sup -} sensor has 72×72 pixels and the pixel size is 83×83 µm{sup 2}. In our design, the beam passes through the beam monitor without hitting the electrodes, making the beam monitor especially suitable for monitoring heavy ion beams. This design also reduces radiation damage to the beam monitor itself. The beam monitor is tested with a carbon ion beam at the Heavy Ion Research Facility in Lanzhou (HIRFL). Results indicate that the beam monitor can measure position, incidence angle and intensity of the beam with a position resolution better than 20 µm, angular resolution about 0.5° and intensity statistical accuracy better than 2%.

  15. All-silicon photonic crystal photoconductor on silicon-on-insulator at telecom wavelength.

    Science.gov (United States)

    Haret, Laurent-Daniel; Checoury, Xavier; Han, Zheng; Boucaud, Philippe; Combrié, Sylvain; De Rossi, Alfredo

    2010-11-08

    We demonstrate an all-silicon photodetector working at telecom wavelength. The device is a simple metal-semiconductor-metal detector fabricated on silicon-on-insulator. A two-dimensional photonic crystal nanocavity (Q=60,000) is used to increase the response that arises from the linear and two-photon absorption of silicon. The responsivity of the detector is about 20 mA/W and its bandwidth is larger than 1 GHz.

  16. Antifuse with a single silicon-rich silicon nitride insulating layer

    Science.gov (United States)

    Habermehl, Scott D.; Apodaca, Roger T.

    2013-01-22

    An antifuse is disclosed which has an electrically-insulating region sandwiched between two electrodes. The electrically-insulating region has a single layer of a non-hydrogenated silicon-rich (i.e. non-stoichiometric) silicon nitride SiN.sub.X with a nitrogen content X which is generally in the range of 0silicon. Arrays of antifuses can also be formed.

  17. Silicon based dielectrics : growth, characterization, and applications in integrated optics

    OpenAIRE

    Ay, Feridun

    2005-01-01

    Cataloged from PDF version of article. In recent years, growing attention has been paid to silicon based dielectrics, such as silicon oxynitrides, silicon nitrides, and semiconductor doped silicon oxides, all combined under the name silica on silicon technology. This attention has been motivated mainly due to their excellent optical properties such as well controlled refractive index and high transparency over a wide range of wavelength. In accordance with the main goal of t...

  18. SiCloud: an online education tool for silicon photonics

    Science.gov (United States)

    Jiang, Cathy Y.; DeVore, Peter T. S.; Lonappan, Cejo Konuparamban; Adam, Jost; Jalali, Bahram

    2017-08-01

    The silicon photonics industry is projected to be a multibillion dollar industry driven by the growth of data centers. In this work, we present an interactive online tool for silicon photonics. Silicon Photonics Cloud (SiCCloud.org) is an easy to use instructional tool for optical properties of silicon and related materials, waveguide design and modal simulations as well as information capacity of silicon channels.

  19. Crystallization behavior of silicon quantum dots in a silicon nitride matrix.

    Science.gov (United States)

    Ha, Rin; Kim, Shinho; Kim, Hyun Jong; Lee, Jung Chul; Bae, Jong-Seong; Kim, Yangdo

    2012-02-01

    Silicon quantum dot superlattice was fabricated by alternating deposition of silicon rich nitride (SRN) and Si3N4 layers using RF magnetron co-sputtering. Samples were then annealed at temperatures between 800 and 1,100 degrees C and characterized by grazing incident X-ray diffraction (GIXRD), transmission electron microscopy (TEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). GIXRD and Raman analyses show that the formation of silicon quantum dots occurs with annealing above 1,100 degrees C for at least 60 minutes. As the annealing time increased the crystallization of silicon quantum dots was also increased. TEM images clearly showed SRN/Si3N4 superlattice structure and silicon quantum dots formation in SRN layers after annealing at 1,100 degrees C for more than 60 minutes. The changes in FTIR transmission spectra observed with annealing condition corresponded to the configuration of Si-N bonds. Crystallization of silicon quantum dots in a silicon nitride matrix started stabilizing after 60 minutes' annealing and approached completion after 120 minutes'. The systematic investigation of silicon quantum dots in a silicon nitride matrix and their properties for solar cell application are presented.

  20. Evidence for a silicon oxycarbide phase in the Nicalon silicon carbide fibre

    Energy Technology Data Exchange (ETDEWEB)

    Porte, L.; Sartre, A.

    1989-01-01

    The Nicalon silicon carbide fibre has been studied by X-ray photoelectron spectroscopy. Elements entering the fiber are carbon, silicon and oxygen. In addition to previously reported chemical entities (silicon carbide, silica and graphitic carbon) evidence is found of the presence of a new supplementary phase which is attributed to an intermediate silicon oxycarbide phase. As this phase is found to participate in very appreciable proportions to the composition of the fiber, some influence on the properties of this fiber can be anticipated. 17 references.

  1. Deep Ultraviolet Macroporous Silicon Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make deep and far UV optical filters from macroporous silicon. This type of filter consists of an array of...

  2. Meie ingel Silicon Valleys / Raigo Neudorf

    Index Scriptorium Estoniae

    Neudorf, Raigo

    2008-01-01

    Ettevõtluse Arendamise Sihtasutuse esinduse töölepanekust USAs Silicon Valleys räägib esinduse juht Andrus Viirg. Vt. ka: Eestlasi leidub San Franciscos omajagu; Muljetavaldav karjäär; USAga ammune tuttav

  3. Meie mees Silicon Valleys / Kertu Ruus

    Index Scriptorium Estoniae

    Ruus, Kertu, 1977-

    2007-01-01

    Ilmunud ka: Delovõje Vedomosti 5. dets. lk. 4. Peaminister Andrus Ansip avas Eesti Ettevõtluse Sihtasutuse esinduse Silicon Valley pealinnas San Joses. Vt. samas: Ränioru kliima on tehnoloogiasõbralik; Andrus Viirg

  4. Silicon based ultrafast optical waveform sampling

    DEFF Research Database (Denmark)

    Ji, Hua; Galili, Michael; Pu, Minhao

    2010-01-01

    A 300 nmx450 nmx5 mm silicon nanowire is designed and fabricated for a four wave mixing based non-linear optical gate. Based on this silicon nanowire, an ultra-fast optical sampling system is successfully demonstrated using a free-running fiber laser with a carbon nanotube-based mode-locker as th......A 300 nmx450 nmx5 mm silicon nanowire is designed and fabricated for a four wave mixing based non-linear optical gate. Based on this silicon nanowire, an ultra-fast optical sampling system is successfully demonstrated using a free-running fiber laser with a carbon nanotube-based mode......-locker as the sampling source. A clear eye-diagram of a 320 Gbit/s data signal is obtained. The temporal resolution of the sampling system is estimated to 360 fs....

  5. Apparatus for silicon nitride precursor solids recovery

    Science.gov (United States)

    Crosbie, Gary M.; Predmesky, Ronald L.; Nicholson, John M.

    1995-04-04

    Method and apparatus are provided for collecting reaction product solids entrained in a gaseous outflow from a reaction situs, wherein the gaseous outflow includes a condensable vapor. A condensate is formed of the condensable vapor on static mixer surfaces within a static mixer heat exchanger. The entrained reaction product solids are captured in the condensate which can be collected for further processing, such as return to the reaction situs. In production of silicon imide, optionally integrated into a production process for making silicon nitride caramic, wherein reactant feed gas comprising silicon halide and substantially inert carrier gas is reacted with liquid ammonia in a reaction vessel, silicon imide reaction product solids entrained in a gaseous outflow comprising residual carrier gas and vaporized ammonia can be captured by forming a condensate of the ammonia vapor on static mixer surfaces of a static mixer heat exchanger.

  6. Method for silicon nitride precursor solids recovery

    Science.gov (United States)

    Crosbie, Gary M.; Predmesky, Ronald L.; Nicholson, John M.

    1992-12-15

    Method and apparatus are provided for collecting reaction product solids entrained in a gaseous outflow from a reaction situs, wherein the gaseous outflow includes a condensable vapor. A condensate is formed of the condensable vapor on static mixer surfaces within a static mixer heat exchanger. The entrained reaction product solids are captured in the condensate which can be collected for further processing, such as return to the reaction situs. In production of silicon imide, optionally integrated into a production process for making silicon nitride caramic, wherein reactant feed gas comprising silicon halide and substantially inert carrier gas is reacted with liquid ammonia in a reaction vessel, silicon imide reaction product solids entrained in a gaseous outflow comprising residual carrier gas and vaporized ammonia can be captured by forming a condensate of the ammonia vapor on static mixer surfaces of a static mixer heat exchanger.

  7. Characterisation of adaptive fluidic silicone membrane lenses

    CSIR Research Space (South Africa)

    Schneider, F

    2009-09-01

    Full Text Available In this paper the auhtors compare the performance and optical quality of two types of adaptive fluidic silicone-membrane lenses. The membranes feature either a homogeneous thickness, or they are shaped resulting in an inhomogeneous cross...

  8. APPLICATION OF ANTIFRICTION ALUMINIUM-SILICON ALLOY

    Directory of Open Access Journals (Sweden)

    V. Ju. Stetsenko

    2010-01-01

    Full Text Available It is shown that antifriction aluminium-silicon alloy is perspective material for change of the parts of heavy and expensive bronze in different frictional units of machines and mechanisms.

  9. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks; (1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  10. Lithium ion batteries based on nanoporous silicon

    Science.gov (United States)

    Tolbert, Sarah H.; Nemanick, Eric J.; Kang, Chris Byung-Hwa

    2015-09-22

    A lithium ion battery that incorporates an anode formed from a Group IV semiconductor material such as porous silicon is disclosed. The battery includes a cathode, and an anode comprising porous silicon. In some embodiments, the anode is present in the form of a nanowire, a film, or a powder, the porous silicon having a pore diameters within the range between 2 nm and 100 nm and an average wall thickness of within the range between 1 nm and 100 nm. The lithium ion battery further includes, in some embodiments, a non-aqueous lithium containing electrolyte. Lithium ion batteries incorporating a porous silicon anode demonstrate have high, stable lithium alloying capacity over many cycles.

  11. Mesoporous Silicon Far Infrared Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make optical filters based on mesoporous silicon multilayers, for use at cold temperatures in the far infrared...

  12. Thermoelectric Properties of Silicon Microchannel Plates Structures

    Energy Technology Data Exchange (ETDEWEB)

    Ci, P L; Shi, J; Wang, F; Sun, L; Xu, S H; Yang, P X; Wang, L W [Laboratory of Polar Materials and Devices, Ministry of Education, and Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China); Chu, Paul K, E-mail: lwwang@ee.ecnu.edu.cn [Department of Physics and Material Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

    2011-02-01

    We have fabricated silicon microchannel plates (MCPs) by photo-assisted electrochemical etching (PAECE) and determined the thermoelectric properties by measuring the Seebeck coefficient of the samples. The samples are composed of regular arrayed lattices with a width of about 5 {mu}m and spacing of about 1 {mu}m. The Seebeck coefficient along the edge of the lattice is 466 {mu}V/K. The silicon MCPs are potential materials for power generation and refrigeration. After oxidation from 30 minutes to 70 minutes and removing the silicon dioxide layer by buffered hydrofluoric acid, the samples show an improved coefficient as high as 1019 {mu}V/K after repeating oxidation and etching 5 times. Our results show that the Seebeck coefficient increases when the wall of the silicon MCPs is thinned.

  13. Semiconductors and semimetals oxygen in silicon

    CERN Document Server

    Willardson, Robert K; Beer, Albert C; Shimura, Fumio

    1994-01-01

    This volume reviews the latest understanding of the behavior and roles of oxygen in silicon, which will carry the field into the ULSI era from the experimental and theoretical points of view. The fourteen chapters, written by recognized authorities representing industrial and academic institutions, cover thoroughly the oxygen related phenomena from the crystal growth to device fabrication processes, as well as indispensable diagnostic techniques for oxygen.Key Features* Comprehensive study of the behavior of oxygen in silicon* Discusses silicon crystals for VLSI and ULSI applications* Thorough coverage from crystal growth to device fabrication* Edited by technical experts in the field* Written by recognized authorities from industrial and academic institutions* Useful to graduate students, scientists in other disciplines, and active participants in the arena of silicon-based microelectronics research* 297 original line drawings

  14. Core-shell silicon nanowire solar cells.

    Science.gov (United States)

    Adachi, M M; Anantram, M P; Karim, K S

    2013-01-01

    Silicon nanowires can enhance broadband optical absorption and reduce radial carrier collection distances in solar cell devices. Arrays of disordered nanowires grown by vapor-liquid-solid method are attractive because they can be grown on low-cost substrates such as glass, and are large area compatible. Here, we experimentally demonstrate that an array of disordered silicon nanowires surrounded by a thin transparent conductive oxide has both low diffuse and specular reflection with total values as low as nanowire facilitates enhancement in external quantum efficiency using two different active shell materials: amorphous silicon and nanocrystalline silicon. As a result, the core-shell nanowire device exhibits a short-circuit current enhancement of 15% with an amorphous Si shell and 26% with a nanocrystalline Si shell compared to their corresponding planar devices.

  15. The two sides of silicon detectors

    CERN Document Server

    Devine, S R

    2001-01-01

    /p/n sup + and essentially two p-n junctions within one device. With increasing bias voltage, as the electric field is extending into the detector bulk from opposite sides of the silicon detector, there are two distinct depletion regions that collect charge signal independently. Summing the signal charge from the two regions, one is able to reconstruct the initial energy of the incident particle. From Transient Current measurements it is apparent that E-field manipulation is possible by excess carrier injection, enabling a high enough E-field to extend across the width of the detector, allowing for efficient charge collection. Results are presented on in situ irradiation of silicon detector's at cryogenic temperature. The results show that irradiation at cryogenic temperatures does not detrimentally effect a silicon detectors performance when compared to its irradiation at room temperature. Operation of silicon devices at cryogenic temperatures offers the advantage of reducing radiation-induced leakage curren...

  16. Some disconnected speculations on slicing silicon

    Science.gov (United States)

    Iles, P. A.

    1982-01-01

    The basic principles for qualifying silicon wafering methods are summarized, and unconventional methods of wafering was discussed. Methods of cleaving analogous to diamond cutting, geological processes employing the expansion of freezing water, and karate chops are touched upon.

  17. Some disconnected speculations on slicing silicon

    Science.gov (United States)

    Iles, P. A.

    1982-02-01

    The basic principles for qualifying silicon wafering methods are summarized, and unconventional methods of wafering was discussed. Methods of cleaving analogous to diamond cutting, geological processes employing the expansion of freezing water, and karate chops are touched upon.

  18. Limits on silicon nanoelectronics for terascale integration.

    Science.gov (United States)

    Meindl, J D; Chen, Q; Davis, J A

    2001-09-14

    Throughout the past four decades, silicon semiconductor technology has advanced at exponential rates in both performance and productivity. Concerns have been raised, however, that the limits of silicon technology may soon be reached. Analysis of fundamental, material, device, circuit, and system limits reveals that silicon technology has an enormous remaining potential to achieve terascale integration (TSI) of more than 1 trillion transistors per chip. Such massive-scale integration is feasible assuming the development and economical mass production of double-gate metal-oxide-semiconductor field effect transistors with gate oxide thickness of about 1 nanometer, silicon channel thickness of about 3 nanometers, and channel length of about 10 nanometers. The development of interconnecting wires for these transistors presents a major challenge to the achievement of nanoelectronics for TSI.

  19. Multispectral imaging with vertical silicon nanowires.

    Science.gov (United States)

    Park, Hyunsung; Crozier, Kenneth B

    2013-01-01

    Multispectral imaging is a powerful tool that extends the capabilities of the human eye. However, multispectral imaging systems generally are expensive and bulky, and multiple exposures are needed. Here, we report the demonstration of a compact multispectral imaging system that uses vertical silicon nanowires to realize a filter array. Multiple filter functions covering visible to near-infrared (NIR) wavelengths are simultaneously defined in a single lithography step using a single material (silicon). Nanowires are then etched and embedded into polydimethylsiloxane (PDMS), thereby realizing a device with eight filter functions. By attaching it to a monochrome silicon image sensor, we successfully realize an all-silicon multispectral imaging system. We demonstrate visible and NIR imaging. We show that the latter is highly sensitive to vegetation and furthermore enables imaging through objects opaque to the eye.

  20. High-efficiency crystalline silicon technology development

    Science.gov (United States)

    Prince, M. B.

    1984-01-01

    The rationale for pursuing high efficiency crystalline silicon technology research is discussed. Photovoltaic energy systems are reviewed as to their cost effectiveness and their competitiveness with other energy systems. The parameters of energy system life are listed and briefly reviewed.

  1. Automotive Radar Sensors in Silicon Technologies

    CERN Document Server

    Jain, Vipul

    2013-01-01

    This book presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors.  This book bridges an existing gap between information available on dependable system/architecture design and circuit design.  It provides the background of the field and detailed description of recent research and development of silicon-based radar sensors.  System-level requirements and circuit topologies for radar transceivers are described in detail. Holistic approaches towards designing radar sensors are validated with several examples of highly-integrated radar ICs in silicon technologies. Circuit techniques to design millimeter-wave circuits in silicon technologies are discussed in depth.  Describes concepts and fundamentals of automotive rada...

  2. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks;(1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  3. Silicon technologies ion implantation and thermal treatment

    CERN Document Server

    Baudrant, Annie

    2013-01-01

    The main purpose of this book is to remind new engineers in silicon foundry, the fundamental physical and chemical rules in major Front end treatments: oxidation, epitaxy, ion implantation and impurities diffusion.

  4. Development of an economical silicon solar cell

    Science.gov (United States)

    Lindmayer, J.

    1975-01-01

    The growth of electronically viable silicon films on inexpensive foreign substrates is studied, with the objective of creating a technology to radically reduce the overall cost of the silicon employed in photovoltaic solar energy conversion. The approach employed is to enhance crystalline ordering during film nucleation by confining arriving silicon atoms to a narrow band traveling across a substrate, i.e., the Lateral Growth Technique (LGT). The efforts have employed physical vapor deposition of silicon in a vacuum evaporator on glass and metal substrates with both slit masks and single defining edges, and subsequent chemical vapor deposition (CVD) of thicker films on these thin film structures by pyrolysis of silane at higher temperatures.

  5. Antireflection/Passivation Step For Silicon Cell

    Science.gov (United States)

    Crotty, Gerald T.; Kachare, Akaram H.; Daud, Taher

    1988-01-01

    New process excludes usual silicon oxide passivation. Changes in principal electrical parameters during two kinds of processing suggest antireflection treatment almost as effective as oxide treatment in passivating cells. Does so without disadvantages of SiOx passivation.

  6. Silicon Germanium Quantum Well Solar Cell Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Quantum-well structures embodied on single crystal silicon germanium drastically enhanced carrier mobilities.  The cell-to-cell circuits of quantum-well PV...

  7. P-type silicon drift detectors

    Energy Technology Data Exchange (ETDEWEB)

    Walton, J.T.; Krieger, B.; Krofcheck, D.; O`Donnell, R.; Odyniec, G.; Partlan, M.D.; Wang, N.W.

    1995-06-01

    Preliminary results on 16 CM{sup 2}, position-sensitive silicon drift detectors, fabricated for the first time on p-type silicon substrates, are presented. The detectors were designed, fabricated, and tested recently at LBL and show interesting properties which make them attractive for use in future physics experiments. A pulse count rate of approximately 8 {times} l0{sup 6} s{sup {minus}1} is demonstrated by the p-type silicon drift detectors. This count rate estimate is derived by measuring simultaneous tracks produced by a laser and photolithographic mask collimator that generates double tracks separated by 50 {mu}m to 1200 {mu}m. A new method of using ion-implanted polysilicon to produce precise valued bias resistors on the silicon drift detectors is also discussed.

  8. Silicon-on ceramic process: silicon sheet growth and device development for the large-area silicon sheet task of the Low-Cost Solar Array Project. Quarterly report NO. 15, April 1, 1980-June 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, A B; Zook, J D; Grung, B L; McHenry, K; Schuldt, S B; Chapman, P W

    1980-07-31

    The objective of this research is to investigate the technical feasibility of producing solar-cell-quality sheet silicon which could meet the DOE cost goals. The Honeywell approach is to coat one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. Results and accomplishments which occurred during the quarter can be summarized as follows: (1) two major problems associated with SCIM-coating wide (10-cm) substrates were identified and solved; (2) the longitudinal temperature profile in SCIM-II has been improved to prevent substrate warping, buckling, and cracking; (3) the transverse temperature profile in SCIM II has been improved to produce more uniform coatings; (4) a strategy to eliminate effects of thermal stress has been developed; (5) the best SOC cell has a total-area conversion efficiency of 10.5% (AM1, AR), for a cell area of 5 cm/sup 2/; (6) a number of experiments are being investigated for improving cell efficiency; (7) for the slow-cooldown experiment, the average efficiency of 29 AR-coated cells was 9.9%, with a standard deviation of 0.3%; (8) encouraging results were obtained on SOC material that had been treated in a hydrogen plasma at Sandia; and (9) thermal modeling has proven to be beneficial in designing modifications of SCIM II.

  9. Silicon nanowire properties from theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Scheel, H.M.

    2007-09-10

    Silicon has played an outstanding role at the end of the 20th century and is still one of the most important components for micro computing. In recent years the ability to miniaturize semiconductor structures and devices to nanometer length scales has opened an all new field of physics, i.e. nanoscience. Simply by miniaturizing the size of semiconducting structures the physics describing electronic or vibronic properties has to be altered fundamentally leading to new phenomena and interesting effects. For silicon the two major mile-stones where the fabrication of porous silicon and later the fabrication of free-standing silicon nanowires. The intense research concerning the fabrication of silicon nanowires has led to single crystalline nanowires with diameters of only a few nanometers. The hope that drove these intense research efforts where to find efficient photonic properties in these quantized systems. In the first part of this work detailed theoretical investigations are presented for the commonly observed ([111] and [11 anti 2]) representatives of free-standing and for the most frequently discussed ([001]) silicon nanowires not (so far) observed as free standing wires. Using density functional theory in the local density approximation the electronic properties as well as the structural changes due to the reduced dimensionality of silicon nanowires are calculated and discussed. The comparison to recent experimental, scanning tunneling experiments reveal a fundamental discrepancy between the calculated band structures and experimental findings. With our results we are able to explain these differences. Raman investigations on silicon nanowires where in a state of controversial discussion about the origin of observed red shifted spectra. Various contributions like quantum confinement, photo excitation and thermal effects where discussed. The second part of this thesis contributes to this discussion, with detailed laser power dependent Raman spectroscopic

  10. Magnetic and electric hotspots with silicon nanodimers.

    Science.gov (United States)

    Bakker, Reuben M; Permyakov, Dmitry; Yu, Ye Feng; Markovich, Dmitry; Paniagua-Domínguez, Ramón; Gonzaga, Leonard; Samusev, Anton; Kivshar, Yuri; Luk'yanchuk, Boris; Kuznetsov, Arseniy I

    2015-03-11

    The study of the resonant behavior of silicon nanostructures provides a new route for achieving efficient control of both electric and magnetic components of light. We demonstrate experimentally and numerically that enhancement of localized electric and magnetic fields can be achieved in a silicon nanodimer. For the first time, we experimentally observe hotspots of the magnetic field at visible wavelengths for light polarized across the nanodimer's primary axis, using near-field scanning optical microscopy.

  11. Silicon photonic thermometer operating on multiple polarizations

    DEFF Research Database (Denmark)

    Guan, Xiaowei; Wang, Xiaoyan; Frandsen, Lars Hagedorn

    2016-01-01

    A silicon photonics optical thermometer simultaneously operating on the multiple polarizations is designed and experimentally demonstrated. Measured sensitivities are 86pm/°C and 48pm/°C for the transverse-electric and transverse-magnetic polarizations, respectively.......A silicon photonics optical thermometer simultaneously operating on the multiple polarizations is designed and experimentally demonstrated. Measured sensitivities are 86pm/°C and 48pm/°C for the transverse-electric and transverse-magnetic polarizations, respectively....

  12. University Crystalline Silicon Photovoltaics Research and Development

    Energy Technology Data Exchange (ETDEWEB)

    Ajeet Rohatgi; Vijay Yelundur; Abasifreke Ebong; Dong Seop Kim

    2008-08-18

    The overall goal of the program is to advance the current state of crystalline silicon solar cell technology to make photovoltaics more competitive with conventional energy sources. This program emphasizes fundamental and applied research that results in low-cost, high-efficiency cells on commercial silicon substrates with strong involvement of the PV industry, and support a very strong photovoltaics education program in the US based on classroom education and hands-on training in the laboratory.

  13. Silicon Nanostructures, Excitonic Interactions, Laser Consequences

    Science.gov (United States)

    2008-07-11

    Optically pumped laser emission is achieved at cryogenic temperatures (ៅK) on carbon- implanted nano -pattemed silicon-on-insulator. By using ion...DISTRIBUTIONIAVAILABIUTY STATEMENT Approved for Public Release; distribution is Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Optically pumped laser emission...is achieved at cryogenic temperatures (ៅK) on carbon-implanted nano -patterned silicon-on-insulator. By using ion-implantation and solid-phase

  14. Dislocation dynamics of web type silicon ribbon

    Science.gov (United States)

    Dillon, O. W., Jr.; Tsai, C. T.; De Angelis, R. J.

    1987-01-01

    Silicon ribbon grown by the dendritic web process passes through a rapidly changing thermal profile in the growth direction. This rapidly changing profile induces stresses which produce changes in the dislocation density in the ribbon. A viscoplastic material response function (Haasen-Sumino model) is used herein to calculate the stresses and the dislocation density at each point in the silicon ribbon. The residual stresses are also calculated.

  15. Revised activation estimates for silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Heinisch, H.L. [Pacific Northwest National Lab., Richland, WA (United States); Cheng, E.T.; Mann, F.M.

    1996-10-01

    Recent progress in nuclear data development for fusion energy systems includes a reevaluation of neutron activation cross sections for silicon and aluminum. Activation calculations using the newly compiled Fusion Evaluated Nuclear Data Library result in calculated levels of {sup 26}Al in irradiated silicon that are about an order of magnitude lower than the earlier calculated values. Thus, according to the latest internationally accepted nuclear data, SiC is much more attractive as a low activation material, even in first wall applications.

  16. Quantum twin spectra in nanocrystalline silicon

    Science.gov (United States)

    Matsumoto, Takahiro; Ohhara, Takashi; Sugimoto, Hidehiko; Bennington, Stephen M.; Ikeda, Susumu

    2017-10-01

    Using inelastic neutron-scattering spectroscopy, we have identified twin-split scattering spectra in hydrogen-terminated nanocrystalline silicon. We show that this duality originates from the cooperative motion of hydrogen and silicon. Our formalism for the inelastic neutron-scattering spectrum, which is derived from the Hermite orthogonal wave functions in terms of the normal coordinates, elucidates the physical origin of the observed quantum twin spectra and predicts the possible occurrence of this behavior in other materials such as metal hydrides.

  17. Nonlinear optical interactions in silicon waveguides

    Directory of Open Access Journals (Sweden)

    Kuyken B.

    2017-03-01

    Full Text Available The strong nonlinear response of silicon photonic nanowire waveguides allows for the integration of nonlinear optical functions on a chip. However, the detrimental nonlinear optical absorption in silicon at telecom wavelengths limits the efficiency of many such experiments. In this review, several approaches are proposed and demonstrated to overcome this fundamental issue. By using the proposed methods, we demonstrate amongst others supercontinuum generation, frequency comb generation, a parametric optical amplifier, and a parametric optical oscillator.

  18. Electrical characteristics of silicon pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Gorelov, I.; Gorfine, G.; Hoeferkamp, M.; Mata-Bruni, V.; Santistevan, G.; Seidel, S.C. E-mail: seidel@dot.phys.unm.edu; Ciocio, A.; Einsweiler, K.; Emes, J.; Gilchriese, M.; Joshi, A.; Kleinfelder, S.; Marchesini, R.; McCormack, F.; Milgrome, O.; Palaio, N.; Pengg, F.; Richardson, J.; Zizka, G.; Ackers, M.; Comes, G.; Fischer, P.; Keil, M.; Martinez, G.; Peric, I.; Runolfsson, O.; Stockmanns, T.; Treis, J.; Wermes, N.; Goessling, C.; Huegging, F.; Klaiber-Lodewigs, J.; Krasel, O.; Wuestenfeld, J.; Wunstorf, R.; Barberis, D.; Beccherle, R.; Caso, C.; Cervetto, M.; Darbo, G.; Gagliardi, G.; Gemme, C.; Morettini, P.; Netchaeva, P.; Osculati, B.; Rossi, L.; Charles, E.; Fasching, D.; Blanquart, L.; Breugnon, P.; Calvet, D.; Clemens, J.-C.; Delpierre, P.; Hallewell, G.; Laugier, D.; Mouthuy, T.; Rozanov, A.; Valin, I.; Andreazza, A.; Caccia, M.; Citterio, M.; Lari, T.; Meroni, C.; Ragusa, F.; Troncon, C.; Vegni, G.; Lutz, G.; Richter, R.H.; Rohe, T.; Boyd, G.R.; Skubic, P.L.; Sicho, P.; Tomasek, L.; Vrba, V.; Holder, M.; Ziolkowski, M.; Cauz, D.; Cobal-Grassmann, M.; D' Auria, S.; De Lotto, B.; Del Papa, C.; Grassmann, H.; Santi, L.; Becks, K.H.; Lenzen, G.; Linder, C

    2002-08-21

    Prototype sensors for the ATLAS silicon pixel detector have been electrically characterized. The current and voltage characteristics, charge-collection efficiencies, and resolutions have been examined. Devices were fabricated on oxygenated and standard detector-grade silicon wafers. Results from prototypes which examine p-stop and standard and moderated p-spray isolation are presented for a variety of geometrical options. Some of the comparisons relate unirradiated sensors with those that have received fluences relevant to LHC operation.

  19. Integrated double-sided silicon microstrip detectors

    Directory of Open Access Journals (Sweden)

    Perevertailo V. L.

    2011-11-01

    Full Text Available The problems of design, technology and manufacturing double-sided silicon microstrip detectors using standard equipment production line in mass production of silicon integrated circuits are considered. The design of prototype high-energy particles detector for experiment ALICE (CERN is presented. The parameters of fabricated detectors are comparable with those of similar foreign detectors, but they are distinguished by lesser cost.

  20. Microtextured Silicon Surfaces for Detectors, Sensors & Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Carey, JE; Mazur, E

    2005-05-19

    With support from this award we studied a novel silicon microtexturing process and its application in silicon-based infrared photodetectors. By irradiating the surface of a silicon wafer with intense femtosecond laser pulses in the presence of certain gases or liquids, the originally shiny, flat surface is transformed into a dark array of microstructures. The resulting microtextured surface has near-unity absorption from near-ultraviolet to infrared wavelengths well below the band gap. The high, broad absorption of microtextured silicon could enable the production of silicon-based photodiodes for use as inexpensive, room-temperature multi-spectral photodetectors. Such detectors would find use in numerous applications including environmental sensors, solar energy, and infrared imaging. The goals of this study were to learn about microtextured surfaces and then develop and test prototype silicon detectors for the visible and infrared. We were extremely successful in achieving our goals. During the first two years of this award, we learned a great deal about how microtextured surfaces form and what leads to their remarkable optical properties. We used this knowledge to build prototype detectors with high sensitivity in both the visible and in the near-infrared. We obtained room-temperature responsivities as high as 100 A/W at 1064 nm, two orders of magnitude higher than standard silicon photodiodes. For wavelengths below the band gap, we obtained responsivities as high as 50 mA/W at 1330 nm and 35 mA/W at 1550 nm, close to the responsivity of InGaAs photodiodes and five orders of magnitude higher than silicon devices in this wavelength region.

  1. Continuous method of producing silicon carbide fibers

    Science.gov (United States)

    Barnard, Thomas Duncan (Inventor); Nguyen, Kimmai Thi (Inventor); Rabe, James Alan (Inventor)

    1999-01-01

    This invention pertains to a method for production of polycrystalline ceramic fibers from silicon oxycarbide (SiCO) ceramic fibers wherein the method comprises heating an amorphous ceramic fiber containing silicon and carbon in an inert environment comprising a boron oxide and carbon monoxide at a temperature sufficient to convert the amorphous ceramic fiber to a polycrystalline ceramic fiber. By having carbon monoxide present during the heating of the ceramic fiber, it is possible to achieve higher production rates on a continuous process.

  2. Stable configurations of graphene on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Javvaji, Brahmanandam; Shenoy, Bhamy Maithry [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Mahapatra, D. Roy, E-mail: droymahapatra@aero.iisc.ernet.in [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Ravikumar, Abhilash [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal 575025 (India); Hegde, G.M. [Center for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012 (India); Rizwan, M.R. [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal 575025 (India)

    2017-08-31

    Highlights: • Simulations of epitaxial growth process for silicon–graphene system is performed. • Identified the most favourable orientation of graphene sheet on silicon substrate. • Atomic local strain due to the silicon–carbon bond formation is analyzed. - Abstract: Integration of graphene on silicon-based nanostructures is crucial in advancing graphene based nanoelectronic device technologies. The present paper provides a new insight on the combined effect of graphene structure and silicon (001) substrate on their two-dimensional anisotropic interface. Molecular dynamics simulations involving the sub-nanoscale interface reveal a most favourable set of temperature independent orientations of the monolayer graphene sheet with an angle of ∽15° between its armchair direction and [010] axis of the silicon substrate. While computing the favorable stable orientations, both the translation and the rotational vibrations of graphene are included. The possible interactions between the graphene atoms and the silicon atoms are identified from their coordination. Graphene sheet shows maximum bonding density with bond length 0.195 nm and minimum bond energy when interfaced with silicon substrate at 15° orientation. Local deformation analysis reveals probability distribution with maximum strain levels of 0.134, 0.047 and 0.029 for 900 K, 300 K and 100 K, respectively in silicon surface for 15° oriented graphene whereas the maximum probable strain in graphene is about 0.041 irrespective of temperature. Silicon–silicon dimer formation is changed due to silicon–carbon bonding. These results may help further in band structure engineering of silicon–graphene lattice.

  3. Metal induced crystallization of silicon germanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gjukic, M.

    2007-05-15

    In the framework of this thesis the applicability of the aluminium-induced layer exchange on binary silicon germanium alloys was studied. It is here for the first time shown that polycrstalline silicon-germanium layers can be fabricated over the whole composition range by the aluminium-induced layer exchange. The experimental results prove thet the resulting material exhibits a polycrystalline character with typocal grain sizes of 10-100 {mu}m. Raman measurements confirm that the structural properties of the resulting layers are because of the large crystallites more comparable with monocrystalline than with nano- or microcrystalline silicon-germanium. The alloy ratio of the polycrystalline layer correspondes to the chemical composition of the amorphous starting layer. The polycrystalline silicon-germanium layers possess in the range of the interband transitions a reflection spectrum, as it is otherwise only known from monocrystalline reference layers. The improvement of the absorption in the photovoltaically relevant spectral range aimed by the application of silicon-germanium could be also proved by absorption measurments. Strongly correlated with the structural properties of the polycrystalline layers and the electronic band structure resulting from this are beside the optical properties also the electrical properties of the material, especially the charge-carrier mobility and the doping concentration. For binary silicon-germanium layers the hole concentration of about 2 x 10{sup 18} cm{sup -3} for pure silicon increrases to about 5 x 10{sup 20} cm{sub -3} for pure germanium. Temperature-resolved measurements were applied in order to detect doping levels respectively semiconductor-metal transitions. In the last part of the thesis the hydrogen passivation of polycrystalline thin silicon-germanium layers, which were fabricated by means of aluminium-induced layer exchange, is treated.

  4. RF transmission lines on silicon substrates

    OpenAIRE

    Ponchak, George E.

    1999-01-01

    A review of RF transmission lines on silicon substrates is presented. Through measurements and calculated results, it is shown that attenuation is dominated by conductor loss if silicon substrates with a resistivity greater than 2500 Q-cm are used. Si passivation layers affect the transmission line attenuation; however, measured results demonstrate that passivation layers do not necessarily increase attenuation. If standard, low resistivity Si wafers must be used, alternative transmission lin...

  5. 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.

  6. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Sampling Artifacts from Conductive Silicone Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.

    2009-05-15

    We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

  8. Hybrid III-V/silicon lasers

    Science.gov (United States)

    Kaspar, P.; Jany, C.; Le Liepvre, A.; Accard, A.; Lamponi, M.; Make, D.; Levaufre, G.; Girard, N.; Lelarge, F.; Shen, A.; Charbonnier, P.; Mallecot, F.; Duan, G.-H.; Gentner, J.-.; Fedeli, J.-M.; Olivier, S.; Descos, A.; Ben Bakir, B.; Messaoudene, S.; Bordel, D.; Malhouitre, S.; Kopp, C.; Menezo, S.

    2014-05-01

    The lack of potent integrated light emitters is one of the bottlenecks that have so far hindered the silicon photonics platform from revolutionizing the communication market. Photonic circuits with integrated light sources have the potential to address a wide range of applications from short-distance data communication to long-haul optical transmission. Notably, the integration of lasers would allow saving large assembly costs and reduce the footprint of optoelectronic products by combining photonic and microelectronic functionalities on a single chip. Since silicon and germanium-based sources are still in their infancy, hybrid approaches using III-V semiconductor materials are currently pursued by several research laboratories in academia as well as in industry. In this paper we review recent developments of hybrid III-V/silicon lasers and discuss the advantages and drawbacks of several integration schemes. The integration approach followed in our laboratory makes use of wafer-bonded III-V material on structured silicon-on-insulator substrates and is based on adiabatic mode transfers between silicon and III-V waveguides. We will highlight some of the most interesting results from devices such as wavelength-tunable lasers and AWG lasers. The good performance demonstrates that an efficient mode transfer can be achieved between III-V and silicon waveguides and encourages further research efforts in this direction.

  9. Prokaryotic silicon utilizing microorganisms in the biosphere

    Science.gov (United States)

    Gupta, D.; Das, S.

    2012-12-01

    Although a little study has been done to determine the silicon utilizing prokaryotes, our previous experiments indicated that almost all Gram-positive bacteria are silicon utilizing; one of them, Streptococci survived exposure on the lunar surface for a long period in experiment done by others. Our initial experiments with these Gram positive microorganisms showed that there were limited growths of these microorganisms on carbon free silicate medium probably with the help of some carry over carbon and nitrogen during cultivation procedures. However, increase in growth rate after repeated subcultures could not be explained at present. The main groups of prokaryotes which were found silicon utilizing microorganisms were Mycobacterium, Bacillus, Nocardia, Streptomyces, Staphylococcus, Streptococcus, Lactobacillus, and Clostridium. In a another previous study by us when silicon level was studied in such grown up cells on carbon "free" silicate medium by electron prove microanalyser, it was found that silicon in cells grown on carbon "free" silicate medium was much higher (24.9%) than those grown on conventional carbon based medium (0.84%). However, these initial findings are encouraging for our future application of this group of organisms on extraterrestrial surfaces for artificial micro-ecosystem formation. It was found that when electropositive elements are less in extraterrestrial situation, then polymerization of silicon-oxygen profusion may occur easily, particularly in carbon and nitrogen paucity in the rocky worlds of the Universe.

  10. Photonic Crystal Sensors Based on Porous Silicon

    Directory of Open Access Journals (Sweden)

    Claudia Pacholski

    2013-04-01

    Full Text Available Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential.

  11. Blue-emitting phosphate glasses synthesized via reduction of tin(IV) by silicon

    Science.gov (United States)

    Jiménez, José A.

    2017-04-01

    The Si-reductant route to produce blue-emitting tin-doped phosphate glasses is proposed. SnO2/Si co-doped glasses were prepared in a P2O5:BaO matrix by a simple melt-quench method in ambient atmosphere. This lead to the silicon-driven reduction of tin(IV) to tin(II) resulting in the production of the luminescent glasses. While the as-prepared SnO2-doped glass appeared non-luminescent, the addition of increasing amounts of silicon powder up to 6 mol% to batch materials facilitated developing the blue-emitting character of the glasses under excitation in the ultraviolet (UV). Reductant-induced luminescent defects became readily noticeable upon addition of the highest amount of silicon. Time-resolved UV-excited emission spectra appeared consistent with the different contributors to the exhibited luminescence being the twofold-coordinated tin centers alongside silicon-related defects. Emission from the latter appeared to be analogous to that of carbon-related defects recently reported, thus supporting that the corresponding luminescence results from the presence of oxygen radicals created by the highly reductive environment irrespective of the element (C or Si).

  12. Quantitative Evaluation of Contamination on Dental Zirconia Ceramic by Silicone Disclosing Agents after Different Cleaning Procedures

    Directory of Open Access Journals (Sweden)

    Sebastian Wille

    2015-05-01

    Full Text Available The aim of this study was to evaluate the effectiveness of cleaning procedures for air-abraded zirconia after contamination with two silicone disclosing agents. Air-abraded zirconia ceramic specimens (IPS e.max ZirCAD were contaminated with either GC Fit Checker white or GC Fit Checker II. Untreated zirconia specimens were used as control. Afterwards the surfaces were cleaned either with waterspray or ultrasonically in 99% isopropanol or using a newly developed cleaning paste (Ivoclean. After cleaning X-ray photoelectron spectroscopy (XPS was performed and the relative peak intensities of Zr, C and Si were used for a qualitative comparison of the residuals. There was no significant difference between the two different silicone disclosing agents. An additional cleaning step with isopropanol led to a significantly lower amount of residuals on the surface, but an additional cleaning process with Ivoclean did not reduce the amount of carbon residuals in comparison to the isopropanol cleaning. Just the silicone amount on the surface was reduced. None of the investigated cleaning processes removed all residuals from the contaminated surface. Standard cleaning processes do not remove all residuals of the silicone disclosing agent from the surface. This may lead to a failure of the resin-ceramic bonding.

  13. Development of Silicon Detectors for the High Luminosity LHC

    Energy Technology Data Exchange (ETDEWEB)

    Eichhorn, Thomas Valentin

    2015-07-15

    The Large Hadron Collider (LHC) at CERN will be upgraded to a High Luminosity LHC in the year 2022, increasing the instantaneous luminosity by a factor of five. This will have major impacts on the experiments at the LHC, such as the Compact Muon Solenoid (CMS) experiment, and especially for their inner silicon tracking systems. Among other things, the silicon sensors used therein will be exposed to unprecedented levels of radiation damage, necessitating a replacement of the entire tracking detector. In order to maintain the excellent current performance, a new tracking detector has to be equipped with sensors of increased radiation hardness and higher granularity. The CMS experiment is undertaking an extensive R and D campaign in the search for the future silicon sensor technology baseline to be used in this upgrade. This thesis presents two methods suitable for use in this search: finite element TCAD simulations and test beam measurements. The simulations are focussed on the interstrip capacitance between sensor strips and are compared to measurements before and after the inclusion of radiation damage effects. A geometrical representation of the strip sensors used in the campaign has been found, establishing the predictive power of simulations. The test beam measurements make use of the high-precision pixel telescopes available at the DESY-II test beam facility. The performance of these telescopes has been assessed and their achievable pointing resolution has been found to be below 2 μm. Thin, epitaxial silicon is a candidate material for usage in radiation hard sensors for the future CMS tracking detector. Sample strip sensors of this material have been irradiated to fluences of up to 1.3 x 10{sup 16} n{sub eq}/cm{sup 2} with 800 MeV or 23 GeV protons. Test beam measurements with 5 GeV electrons have been performed to investigate the radiation hardness of epitaxial sensors using the pixel beam telescopes. The epitaxial device under test (DUT) has been integrated

  14. Silicon material technology status. [assessment for electronic and photovoltaic applications

    Science.gov (United States)

    Lutwack, R.

    1983-01-01

    Silicon has been the basic element for the electronic and photovoltaic industries. The use of silicon as the primary element for terrestrial photovoltaic solar arrays is projected to continue. The reasons for this projection are related to the maturity of silicon technology, the ready availability of extremely pure silicon, the performance of silicon solar cells, and the considerable present investment in technology and manufacturing facilities. The technologies for producing semiconductor grade silicon and, to a lesser extent, refined metallurgical grade silicon are considered. It is pointed out that nearly all of the semiconductor grade silicon is produced by processes based on the Siemens deposition reactor, a technology developed 26 years ago. The state-of-the-art for producing silicon by this process is discussed. It is expected that efforts to reduce polysilicon process costs will continue.

  15. Strained silicon as a new electro-optic material

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  16. Amorphous silicon rich silicon nitride optical waveguides for high density integrated optics

    DEFF Research Database (Denmark)

    Philipp, Hugh T.; Andersen, Karin Nordström; Svendsen, Winnie Edith

    2004-01-01

    Amorphous silicon rich silicon nitride optical waveguides clad in silica are presented as a high-index contrast platform for high density integrated optics. Performance of different cross-sectional geometries have been measured and are presented with regards to bending loss and insertion loss...

  17. Modulation Doping of Silicon using Aluminium-induced Acceptor States in Silicon Dioxide

    Science.gov (United States)

    König, Dirk; Hiller, Daniel; Gutsch, Sebastian; Zacharias, Margit; Smith, Sean

    2017-01-01

    All electronic, optoelectronic or photovoltaic applications of silicon depend on controlling majority charge carriers via doping with impurity atoms. Nanoscale silicon is omnipresent in fundamental research (quantum dots, nanowires) but also approached in future technology nodes of the microelectronics industry. In general, silicon nanovolumes, irrespective of their intended purpose, suffer from effects that impede conventional doping due to fundamental physical principles such as out-diffusion, statistics of small numbers, quantum- or dielectric confinement. In analogy to the concept of modulation doping, originally invented for III-V semiconductors, we demonstrate a heterostructure modulation doping method for silicon. Our approach utilizes a specific acceptor state of aluminium atoms in silicon dioxide to generate holes as majority carriers in adjacent silicon. By relocating the dopants from silicon to silicon dioxide, Si nanoscale doping problems are circumvented. In addition, the concept of aluminium-induced acceptor states for passivating hole selective tunnelling contacts as required for high-efficiency photovoltaics is presented and corroborated by first carrier lifetime and tunnelling current measurements. PMID:28425460

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

    NARCIS (Netherlands)

    Lambertz, A.

    2015-01-01

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

  19. Monolithics silicon nano-ridge fabrication by edge lithography and wet anisotropic etching of silicon

    NARCIS (Netherlands)

    Zhao, Yiping; Berenschot, Johan W.; Jansen, Henricus V.; Tas, Niels Roelof; Huskens, Jurriaan; Elwenspoek, Michael Curt

    2008-01-01

    A new nanofabrication scheme is presented to form stamps useful in thermal nanoimprint lithography (T-NIL). The stamp is created in <110> single crystalline silicon using a full wet etching procedure including local oxidation of silicon (LOCOS)and employing an adapted edge lithography technique on

  20. Microstructure Control of Columnar-Grained Silicon Substrate Solidified from Silicon Melts Using Gas Pressure

    Directory of Open Access Journals (Sweden)

    Jun-Kyu Lee

    2015-01-01

    Full Text Available A silicon substrate with the dimensions of 100 × 140 × 0.3 mm was grown directly from liquid silicon with gas pressure. The silicon melt in the sealed melting part was injected into the growth part at applied pressure of 780–850 Torr. The solidified silicon substrate was then transferred by the pull of the cooled dummy bar. A desirable structure with a liquid-solid interface perpendicular to the pulling direction was formed when the mold temperature in the solidification zone of the growth part was much higher than that of the dummy bar, as this technique should be able to overcome thermal loss through the molds and the limited heat flux derived from the very narrow contact area between the silicon melt and the dummy bar. In addition, because the metallic impurities and expansion of volume during solidification are preferably moved to a liquid phase, a high-quality silicon substrate, without defects such as cracks and impurities in the substrate, could be manufactured in the interface structure. The present study reports the experimental findings on a new and direct growth system for obtaining silicon substrates characterized by high quality and productivity, as a candidate for alternate routes for the fabrication of silicon substrates.

  1. Heat-Induced Agglomeration of Amorphous Silicon Nanoparticles Toward the Formation of Silicon Thin Film.

    Science.gov (United States)

    Jang, Bo Yun; Kim, Ja Young; Seo, Gyeongju; Shin, Chae-Ho; Ko, Chang Hyun

    2016-01-01

    The thermal behavior of silicon nanoparticles (Si NPs) was investigated for the preparation of silicon thin film using a solution process. TEM analysis of Si NPs, synthesized by inductively coupled plasma, revealed that the micro-structure of the Si NPs was amorphous and that the Si NPs had melted and merged at a comparatively low temperature (~750 °C) considering bulk melting temperature of silicon (1414 °C). A silicon ink solution was prepared by dispersing amorphous Si NPs in propylene glycol (PG). It was then coated onto a silicon wafer and a quartz plate to form a thin film. These films were annealed in a vacuum or in an N₂ environment to increase their film density. N2 annealing at 800 °C and 1000 °C induced the crystallization of the amorphous thin film. An elemental analysis by the SIMS depth profile showed that N₂annealing at 1000 °C for 180 min drastically reduced the concentrations of carbon and oxygen inside the silicon thin film. These results indicate that silicon ink prepared using amorphous Si NPs in PG can serve as a proper means of preparing silicon thin film via solution process.

  2. Modification of silicon nitride and silicon carbide surfaces for food and biosensor applications

    NARCIS (Netherlands)

    Rosso, M.

    2009-01-01

    Silicon-rich silicon nitride (SixN4, x > 3) is a robust insulating material widely used for the coating of microdevices: its high chemical and mechanical inertness make it a material of choice for the reinforcement of fragile microstructures (e.g. suspended microcantilevers, micro-fabricated

  3. Phosphorus-doped Amorphous Silicon Nitride Films Applied to Crystalline Silicon Solar Cells

    NARCIS (Netherlands)

    Feinäugle, Matthias

    2008-01-01

    The Photovoltaics Group at the Universitat Politècnica de Catalunya is investigating silicon carbide (SiC) for the electronic passivation of the surface of crystalline silicon solar cells. The doping of SiC passivation layers with phosphorus resulted in a clear improvement of the minority carrier

  4. Silicon oxide nanoimprint stamp fabrication by edge lithography reinforced with silicon nitride

    NARCIS (Netherlands)

    Zhao, Yiping; Berenschot, Johan W.; de Boer, Meint J.; Jansen, Henricus V.; Tas, Niels Roelof; Huskens, Jurriaan; Elwenspoek, Michael Curt

    2007-01-01

    The fabrication of silicon oxide nanoimprint stamp employing edge lithography in combination with silicon nitride deposition is presented. The fabrication process is based on conventional photolithography an weg etching methods. Nanoridges with width dimension of sub-20 nm were fabricated by edge

  5. Surface etching, chemical modification and characterization of silicon nitride and silicon oxide - Selective functionalization of Si

    NARCIS (Netherlands)

    Liu, Li Hong; Michalak, David J.; Chopra, Tatiana P.; Pujari, Sidharam P.; Zuilhof, Han

    2016-01-01

    The ability to selectively chemically functionalize silicon nitride (Si3N4) or silicon dioxide (SiO2) surfaces after cleaning would open interesting technological applications. In order to achieve this goal, the chemical composition of surfaces needs to be

  6. Brachytherapy dosimeter with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Moutinho, L.M., E-mail: moutinho@ua.pt [i3N, Physics Department, University of Aveiro (Portugal); Castro, I.F.C. [i3N, Physics Department, University of Aveiro (Portugal); Peralta, L. [Faculdade de Ciências da Universidade de Lisboa (Portugal); Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Abreu, M.C. [Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Veloso, J.F.C.A. [i3N, Physics Department, University of Aveiro (Portugal)

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40–50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25–100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  7. Mechanism of fluorescent silicon nanoparticles

    Science.gov (United States)

    So, Woong Young; Li, Qi; Jin, Rongchao; Peteanu, Linda

    2017-08-01

    Silicon (Si) is known to have an indirect bandgap transition, which means it has poor fluorescence properties. However, when engineered into sub-nm sized particles, Si nanoparticles become emissive due to quantum confinement. However, in unmodified Si particles, this effect is limited to generating red or near-infrared emission with low quantum yield. To resolve these limitations, surface-modification methods have successfully generated Si particles that emit in the blue, cyan, and green with quantum yields up to 90%.1,2 These modifications have also made the Si nanoparticles watersoluble, making them promising in biological applications. To date, the mechanism of emission in these species is still unclear although it has been speculated that charge transfer of Si-O-N could be responsible. To investigate whether emission by these Si nanoparticles proceeds via a charge transfer mechanism, Stark spectroscopy is used. In this method, an external electric field is applied to the Si nanoparticles. Changes in the absorption and/or emission spectra due to the applied field can be taken as strong evidence for a charge transfer mechanism. From the results of Stark spectroscopy, Si nanoparticles are revealed to have ligand to metal charge transfer mechanism along with electric-field quenching, which is useful information for utilization into applications. Addition to the information found, a method of how to tune the emission maxima based on selection of ligands is prosed.

  8. Plant Physiological Aspects of Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, E.; Fan, T.W-M.; Higashi, R.M.; Silk, W.K.

    2002-07-10

    The element silicon, Si, represents an anomaly in plant physiology (Epstein, 1994, 1999b). Plants contain the element in amounts comparable to those of such macronutrient elements as phosphorus, calcium, magnesium, viz. at tissue concentrations (dry weight basis) of about 0.1-10%, although both lower and higher values may be encountered. In some plants, such as rice and sugarcane, Si may be the mineral element present in largest amount. In much of plant physiological research, however, Si is considered a nonentity. Thus, not a single formulation of the widely used nutrient solutions includes Si. Experimental plants grown in these solutions are therefore abnormally low in their content of the element, being able to obtain only what Si is present as an unavoidable contaminant of the nutrient salts used, and from the experimental environment and their own seeds. The reason for the astonishing discrepancy between the prominence of Si in plants and its neglect in much of the enterprise of plant physiological research is that Si does not qualify as an ''essential'' element. Ever since the introduction of the solution culture method in the middle of the last century (Epstein, 1999a, b) it has been found that higher plants can grow in nutrient solutions in the formulation of which Si is not included. The only exceptions are the Equisitaceae (horsetails or scouring rushes), for which Si is a quantitatively major essential element.

  9. Simulation of Silicon Photomultiplier Signals

    Science.gov (United States)

    Seifert, Stefan; van Dam, Herman T.; Huizenga, Jan; Vinke, Ruud; Dendooven, Peter; Lohner, Herbert; Schaart, Dennis R.

    2009-12-01

    In a silicon photomultiplier (SiPM), also referred to as multi-pixel photon counter (MPPC), many Geiger-mode avalanche photodiodes (GM-APDs) are connected in parallel so as to combine the photon counting capabilities of each of these so-called microcells into a proportional light sensor. The discharge of a single microcell is relatively well understood and electronic models exist to simulate this process. In this paper we introduce an extended model that is able to simulate the simultaneous discharge of multiple cells. This model is used to predict the SiPM signal in response to fast light pulses as a function of the number of fired cells, taking into account the influence of the input impedance of the SiPM preamplifier. The model predicts that the electronic signal is not proportional to the number of fired cells if the preamplifier input impedance is not zero. This effect becomes more important for SiPMs with lower parasitic capacitance (which otherwise is a favorable property). The model is validated by comparing its predictions to experimental data obtained with two different SiPMs (Hamamatsu S10362-11-25u and Hamamatsu S10362-33-25c) illuminated with ps laser pulses. The experimental results are in good agreement with the model predictions.

  10. Silicon-based nanoenergetic composites

    Energy Technology Data Exchange (ETDEWEB)

    Asay, Blaine [Los Alamos National Laboratory; Son, Steven [PURDUE UNIV; Mason, Aaron [PURDUE UNIV; Yarrington, Cole [PURDUE UNIV; Cho, K Y [PURDUE UNIV; Gesner, J [PSU; Yetter, R A [PSU

    2009-01-01

    Fundamental combustion properties of silicon-based nano-energetic composites was studied by performing equilibrium calculations, 'flame tests', and instrumented burn-tube tests. That the nominal maximum flame temperature and for many Si-oxidizer systems is about 3000 K, with exceptions. Some of these exceptions are Si-metal oxides with temperatures ranging from 2282 to 2978 K. Theoretical maximum gas production of the Si composites ranged from 350-6500 cm{sup 3}/g of reactant with NH{sub 4}ClO{sub 4} - Si producing the most gas at 6500 cm{sup 3}/g and Fe{sub 2}O{sub 3} producing the least. Of the composites tested NH{sub 4}ClO{sub 4} - Si showed the fastest burning rates with the fastest at 2.1 km/s. The Si metal oxide burning rates where on the order of 0.03-75 mls the slowest of which was nFe{sub 2}O{sub 3} - Si.

  11. The Belle II VXD production database

    Energy Technology Data Exchange (ETDEWEB)

    Valentan, Manfred; Ritter, Martin [Max-Planck-Institut fuer Physik, Muenchen (Germany); Wuerkner, Benedikt; Leitl, Bernhard [Institut fuer Hochenergiephysik, Wien (Austria); Pilo, Federico [Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Collaboration: Belle II-Collaboration

    2015-07-01

    The construction and commissioning of the Belle II Vertex Detector (VXD) is a huge endeavor involving a large number of valuable components. Both subsystems PXD (Pixel Detector) and SVD (Silicon Vertex Detector) deploy a large number of sensors, readout electronic parts and mechanical elements. These items are scattered around the world at many institutes, where they are built, measured and assembled. One has to keep track of measurement configurations and results, know at any time the location of the sensors, their processing state, quality, where they end up in an assembly, and who is responsible. These requirements call for a flexible and extensive database which is able to reflect the processes in the laboratories and the logistics between the institutes. This talk introduces the database requirements of a physics experiment using the PXD construction workflow as a showcase, and presents an overview of the database ''HephyDb'', which is used by the groups constructing the Belle II VXD.

  12. Strontium and barium isotopes in presolar silicon carbide grains measured with CHILI-two types of X grains

    Science.gov (United States)

    Stephan, Thomas; Trappitsch, Reto; Davis, Andrew M.; Pellin, Michael J.; Rost, Detlef; Savina, Michael R.; Jadhav, Manavi; Kelly, Christopher H.; Gyngard, Frank; Hoppe, Peter; Dauphas, Nicolas

    2018-01-01

    We used CHILI, the Chicago Instrument for Laser Ionization, a new resonance ionization mass spectrometer developed for isotopic analysis of small samples, to analyze strontium, zirconium, and barium isotopes in 22 presolar silicon carbide grains. Twenty of the grains showed detectable strontium and barium, but none of the grains had enough zirconium to be detected with CHILI. Nine grains were excluded from further consideration since they showed very little signals (barium. Among the 11 remaining grains, we found three X grains. The discovery of three supernova grains among only 22 grains was fortuitous, because only ∼1% of presolar silicon carbide grains are type X, but was confirmed by silicon isotopic measurements of grain residues with NanoSIMS. While one of the X grains showed strontium and barium isotope patterns expected for supernova grains, the two other supernova grains have 87Sr/86Sr barium isotopic composition constrain their individual formation conditions in Type II supernovae.

  13. Colloidal silicon quantum dots: synthesis and luminescence tuning from the near-UV to the near-IR range

    Directory of Open Access Journals (Sweden)

    Batu Ghosh

    2014-01-01

    Full Text Available This review describes a series of representative synthesis processes, which have been developed in the last two decades to prepare silicon quantum dots (QDs. The methods include both top-down and bottom-up approaches, and their methodological advantages and disadvantages are presented. Considerable efforts in surface functionalization of QDs have categorized it into (i a two-step process and (ii in situ surface derivatization. Photophysical properties of QDs are summarized to highlight the continuous tuning of photoluminescence color from the near-UV through visible to the near-IR range. The emission features strongly depend on the silicon nanostructures including QD surface configurations. Possible mechanisms of photoluminescence have been summarized to ascertain the future challenges toward industrial use of silicon-based light emitters.

  14. The dark side of silicon energy efficient computing in the dark silicon era

    CERN Document Server

    Liljeberg, Pasi; Hemani, Ahmed; Jantsch, Axel; Tenhunen, Hannu

    2017-01-01

    This book presents the state-of-the art of one of the main concerns with microprocessors today, a phenomenon known as "dark silicon". Readers will learn how power constraints (both leakage and dynamic power) limit the extent to which large portions of a chip can be powered up at a given time, i.e. how much actual performance and functionality the microprocessor can provide. The authors describe their research toward the future of microprocessor development in the dark silicon era, covering a variety of important aspects of dark silicon-aware architectures including design, management, reliability, and test. Readers will benefit from specific recommendations for mitigating the dark silicon phenomenon, including energy-efficient, dedicated solutions and technologies to maximize the utilization and reliability of microprocessors. Enables readers to understand the dark silicon phenomenon and why it has emerged, including detailed analysis of its impacts; Presents state-of-the-art research, as well as tools for mi...

  15. Metallic coatings on silicon substrates, and methods of forming metallic coatings on silicon substrates

    Science.gov (United States)

    Branagan, Daniel J [Idaho Falls, ID; Hyde, Timothy A [Idaho Falls, ID; Fincke, James R [Los Alamos, NM

    2008-03-11

    The invention includes methods of forming a metallic coating on a substrate which contains silicon. A metallic glass layer is formed over a silicon surface of the substrate. The invention includes methods of protecting a silicon substrate. The substrate is provided within a deposition chamber along with a deposition target. Material from the deposition target is deposited over at least a portion of the silicon substrate to form a protective layer or structure which contains metallic glass. The metallic glass comprises iron and one or more of B, Si, P and C. The invention includes structures which have a substrate containing silicon and a metallic layer over the substrate. The metallic layer contains less than or equal to about 2 weight % carbon and has a hardness of at least 9.2 GPa. The metallic layer can have an amorphous microstructure or can be devitrified to have a nanocrystalline microstructure.

  16. Synthesis of Novel Reactive Disperse Silicon-Containing Dyes and Their Coloring Properties on Silicone Rubbers

    Directory of Open Access Journals (Sweden)

    Ning Yu

    2018-01-01

    Full Text Available Novel red and purple reactive disperse silicon-containing dyes were designed and synthesized using p-nitroaniline and 6-bromo-2,4-dinitro-aniline as diazonium components, the first condensation product of cyanuric chloride and 3-(N,N-diethylamino-aniline as coupling component, and 3-aminopropylmethoxydimethylsilane, 3-aminopropylmethyldimethoxysilane, and 3-aminopropyltrimethoxysilane as silicone reactive agents. These dyes were characterized by UV-Vis, 1H-NMR, FT-IR, and MS. The obtained reactive disperse silicon-containing dyes were used to color silicone rubbers and the color fastness of the dyes were evaluated. The dry/wet rubbing and washing fastnesses of these dyes all reached 4–5 grade and the sublimation fastness was also above 4 grade, indicating outstanding performance in terms of color fastness. Such colored silicone rubbers showed bright and rich colors without affecting its static mechanical properties.

  17. Reduced thermal conductivity of isotopically modulated silicon multilayer structures

    DEFF Research Database (Denmark)

    Bracht, H.; Wehmeier, N.; Eon, S.

    2012-01-01

    -resolved x-ray scattering. Comparison of the experimental results to numerical solutions of the corresponding heat diffusion equations reveals a factor of three lower thermal conductivity of the isotope structure compared to natural Si. Our results demonstrate that the thermal conductivity of silicon can......We report measurements of the thermal conductivity of isotopically modulated silicon that consists of alternating layers of highly enriched silicon-28 and silicon-29. A reduced thermal conductivity of the isotopically modulated silicon compared to natural silicon was measured by means of time...

  18. Anatomy of a Silicon Compiler

    Science.gov (United States)

    1994-10-04

    CATHEDRAL-II compiler has been adapted and reworked by the Phil- ips Corp. into the PIRAMID environment [Delaruelle88]. From this commercial- ization and...of a declarative DSP programming environment. 220 Behavioral Synthesis Part IV REFERENCES [Delaruelle8S] A. Delaruelie et al., "Design of a syndrome ...generator chip using tde PIRAMID Design System", Proc. FSSCIRC Co4f., pp 256-259, Manchiester. September 1988. [Demang6J H. Do Man,.J. Rabasy, P. Six

  19. (ii) and ni (ii) complexes with n

    African Journals Online (AJOL)

    DR. AMINU

    II) complexes with a. Schiff base derived from. 4-dimetylamino benzaldehyde and primary amines. The chemical analysis data showed the formation of (1:1) metal - ligand ratio and a square planar geometry was suggested for Co(II) and Ni(II) ...

  20. manganese(II) and uranyl(II)

    African Journals Online (AJOL)

    Paper electrophoresis is used for the study of equilibria in binary complex systems in solution. The stability constants of ML and ML2 complex species of some metal ions copper(II), manganese(II) and uranyl(II) with a-aminobutenoic acid and hydroxyproline were determined at an ionic strength of 0.1 M and 35 ºC.

  1. Elizabeth II uus kunstigalerii

    Index Scriptorium Estoniae

    1999-01-01

    Tähistamaks oma troonile asumise 50. aastapäeva, avab Elizabeth II 6. II 2002 Buckinghami palees uue kunstigalerii, mis ehitatakse palee tiibhoonena. Arhitekt John Simpson. Elizabeth II kunstikogust

  2. Spreading of aqueous solutions of trisiloxanes and conventional surfactants over PTFE AF coated silicone wafers.

    Science.gov (United States)

    Ivanova, Natalia; Starov, Victor; Johnson, Daniel; Hilal, Nidal; Rubio, Ramon

    2009-04-09

    Kinetics of spreading of aqueous trisiloxane surfactant T(n) (with n = 4, 6, and 8 ethoxy groups) solutions and conventional aqueous surfactant solutions (Tween 20, C12E4, SDS) over silicon wafers coated with PTFE AF is experimentally investigated. It has been found that trisiloxane solutions spread on highly hydrophobic PTFE AF coated silicone wafers; however, they do not show superspreading behavior on these highly hydrophobic substrates. Solutions of conventional nonionic surfactants investigated show kinetics of spreading similar to trisiloxanes. Three regimes of spreading have been identified (i) complete non-wetting during the spreading process at low concentrations, (ii) a transition from initial nonwetting to partial wetting at the end of the spreading process at intermediate concentrations, and (iii) partial wetting both at the beginning and the end of the spreading process at higher concentrations. Transition from the first regime (i) to the second regime (ii) takes place at the critical aggregation concentration (CAC) or critical micelle concentration (CMC), transition from regime (ii) to regime (iii) happens at the critical wetting concentration (CWC). In the case of regime (i) the spreading of nonionic surfactants solutions investigated on PTFE AF coated silicone wafers is slow and follows a theoretically predicted law (Starov; et al. J. Colloid Interface Sci. 2000, 227 (1), 185). In the case of regimes (ii) and (iii), the spreading of the nonionic surfactant solutions investigated proceeds in two stages: the fast short first stage, which is followed by a much slower second stage. It is shown that the slow stage develops according to a previously described theoretical model. According to this theory the surfactant molecules adsorb in front of the moving three-phase contact line (autophilic phenomenon), which results in a partial hydrophilisation of an initially hydrophobic substrate and a spreading as a consequence. We assume that the first stage of

  3. Amorphous silicon detectors in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  4. Stretchable and foldable silicon-based electronics

    KAUST Repository

    Cavazos Sepulveda, Adrian Cesar

    2017-03-30

    Flexible and stretchable semiconducting substrates provide the foundation for novel electronic applications. Usually, ultra-thin, flexible but often fragile substrates are used in such applications. Here, we describe flexible, stretchable, and foldable 500-μm-thick bulk mono-crystalline silicon (100) “islands” that are interconnected via extremely compliant 30-μm-thick connectors made of silicon. The thick mono-crystalline segments create a stand-alone silicon array that is capable of bending to a radius of 130 μm. The bending radius of the array does not depend on the overall substrate thickness because the ultra-flexible silicon connectors are patterned. We use fracture propagation to release the islands. Because they allow for three-dimensional monolithic stacking of integrated circuits or other electronics without any through-silicon vias, our mono-crystalline islands can be used as a “more-than-Moore” strategy and to develop wearable electronics that are sufficiently robust to be compatible with flip-chip bonding.

  5. LASSA: Large Area Silicon Strip Array

    Science.gov (United States)

    Davin, B.; Desouza, R. T.; Yanez, R.; Church, J.; Gelbke, C. K.; Liu, T.; Lynch, W. G.; Moehlenkamp, T.; Tan, T.; Tsang, M. B.; Wagner, A.; Charity, R. J.; Sarantites, D. G.; Sobotka, L. G.

    1998-04-01

    An IU-MSU-WU collaboration is designing and building a new array for detecting isotopically resolved intermediate mass fragments (IMF: 3<=Z<=10) and light charged particles (LCP: Z<=2) with good spatial resolution and low energy thresholds. The first element of each telescope consists of a 5 cm x 5 cm 65 μ m passivated silicon detector. This thin silicon detector is backed by a 500 μ m detector of the same area. These silicon detectors are mounted in a compact geometry which minimizes dead area. To allow detection of LCP, the silicon detectors are backed by 6 cm thick CsI(Tl) crystals with photodiode readout. The 65 μ m silicon has 16 strips on its front surface while the 500 μ m has 16 strips on the front surface with an additional 16 strips oriented orthogonally on the back surface which allows two dimensional position information for both IMFs and LCPs. The array has nine telescopes in a 3x3 arrangement to optimize the measurement of small angle IMF-IMF coincidences in heavy-ion induced multifragmention reactions. Design details, efficiency calculations, and early prototype results will be presented.

  6. A single-photon counting “edge-on” silicon detector for synchrotron radiation mammography

    Science.gov (United States)

    Rigon, L.; Arfelli, F.; Astolfo, A.; Bergamaschi, A.; Dreossi, D.; Longo, R.; Menk, R.-H.; Schmitt, B.; Vallazza, E.; Castelli, E.

    2009-09-01

    The Phase Imaging for Clinical Application with Silicon detector and Synchrotron radiatiOn (PICASSO) project is developing an "edge-on" silicon microstrip detector for mammography with synchrotron radiation. The sensor is equipped with a fast single-photon counting electronics based on the Mythen-II application-specific integrated circuit. A first prototype has been assembled and tested at the SYnchrotron Radiation for MEdical Physics (SYRMEP) beamline at Elettra in Trieste, Italy. The first results are presented in this study including evidence of high-rate single-photon counting with negligible losses up to 1.2×10 6 incident photons per pixel per second; spatial resolution consistent with the pixel aperture (0.3 mm×0.05 mm); high-quality imaging of test-objects, obtained with a dose comparable to the one delivered in modern full-field digital mammographic systems.

  7. Silicon strip prototypes for the ATLAS Upgrade tracker of the HL-LHC

    CERN Document Server

    Díez, S; The ATLAS collaboration

    2012-01-01

    This paper describes the integration structures for the silicon strips tracker of the ATLAS detector for the Phase-II upgrade of the Large Hadron Collider (LHC), also referred to as High-Luminosity LHC (HL-LHC). Silicon strip sensors are arranged in highly modular structures, called `staves' and `petals'. This paper focuses on the prototyping effort developed by the strips tracker barrel community, as well as on the description of one of the latest stave prototypes. This new prototype is composed of a particular core structure, in which a shield-less bus tape is embedded in between carbon fiber lay-ups. Electrical and thermal performances of the prototype are presented, as well as a description of the assembly procedures and tools.

  8. Porosity-dependent fractal nature of the porous silicon surface

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, N.; Dariani, R. S., E-mail: dariani@alzahra.ac.ir [Department of Physics, Alzahra University, Tehran, 1993893973 (Iran, Islamic Republic of)

    2015-07-15

    Porous silicon films with porosity ranging from 42% to 77% were fabricated by electrochemical anodization under different current density. We used atomic force microscopy and dynamic scaling theory for deriving the surface roughness profile and processing the topography of the porous silicon layers, respectively. We first compared the topography of bare silicon surface with porous silicon and then studied the effect of the porosity of porous silicon films on their scaling behavior by using their self-affinity nature. Our work demonstrated that silicon compared to the porous silicon films has the highest Hurst parameter, indicating that the formation of porous layer due to the anodization etching of silicon surface leads to an increase of its roughness. Fractal analysis revealed that the evolution of the nanocrystallites’ fractal dimension along with porosity. Also, we found that both interface width and Hurst parameter are affected by the increase of porosity.

  9. Curvature Control of Silicon Microlens for THz Dielectric Antenna

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam; Cooper, Ken; Mehdi, Imran

    2012-01-01

    We have controlled the curvature of silicon microlens by changing the amount of photoresist in order to microfabricate hemispherical silicon microlens which can improve the directivity and reduce substrate mode losses.

  10. Advanced Silicone-based Coatings for Flexible Fabric Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High performance silicone coatings are desired for flexible fabrics used in several space and consumer applications. For instance, the total weight of silicone...

  11. Silicon-based microreactors as research tools in chemistry

    NARCIS (Netherlands)

    Tiggelaar, Roald M.; Gardeniers, Johannes G.E.; van den Berg, Albert

    In this contribution suitability of silicon-technology based microreactors for performing research on reactions where temperature control is essential is discussed. The versatility of silicon micromachining technology is elucidated by describing the fabrication and performance of two types of

  12. Widely tunable Vernier ring laser on hybrid silicon

    National Research Council Canada - National Science Library

    Hulme, J C; Doylend, J K; Bowers, J E

    2013-01-01

    A hybrid silicon tunable Vernier ring laser is designed and fabricated by integration of two intra-cavity ring resonators, hybrid III-V-on-silicon gain elements, and resistive heaters for thermal tuning...

  13. Design and Fabrication of Silicon-on-Silicon-Carbide Substrates and Power Devices for Space Applications

    Directory of Open Access Journals (Sweden)

    Gammon P.M.

    2017-01-01

    Full Text Available A new generation of power electronic semiconductor devices are being developed for the benefit of space and terrestrial harsh-environment applications. 200-600 V lateral transistors and diodes are being fabricated in a thin layer of silicon (Si wafer bonded to silicon carbide (SiC. This novel silicon-on-silicon-carbide (Si/SiC substrate solution promises to combine the benefits of silicon-on-insulator (SOI technology (i.e device confinement, radiation tolerance, high and low temperature performance with that of SiC (i.e. high thermal conductivity, radiation hardness, high temperature performance. Details of a process are given that produces thin films of silicon 1, 2 and 5 μm thick on semi-insulating 4H-SiC. Simulations of the hybrid Si/SiC substrate show that the high thermal conductivity of the SiC offers a junction-to-case temperature ca. 4× less that an equivalent SOI device; reducing the effects of self-heating, and allowing much greater power density. Extensive electrical simulations are used to optimise a 600 V laterally diffused metal-oxide-semiconductor field-effect transistor (LDMOSFET implemented entirely within the silicon thin film, and highlight the differences between Si/SiC and SOI solutions.

  14. Evidence for a Regulatory Role of Diatom Silicon Transporters in Cellular Silicon Responses

    Science.gov (United States)

    Shrestha, Roshan P.

    2014-01-01

    The utilization of silicon by diatoms has both global and small-scale implications, from oceanic primary productivity to nanotechnological applications of their silica cell walls. The sensing and transport of silicic acid are key aspects of understanding diatom silicon utilization. At low silicic acid concentrations (silicon starvation. SIT1 and SIT2 were localized in the plasma membrane, and protein levels were generally inversely correlated with cellular silicon needs, with a distinct response being found when the two SITs were compared. We developed highly effective approaches for RNA interference and antisense knockdowns, the first such approaches developed for a centric diatom. SIT knockdown differentially affected the uptake of silicon and the incorporation of silicic acid and resulted in the induction of lipid accumulation under silicon starvation conditions far earlier than in the wild-type cells, suggesting that the cells were artificially sensing silicon limitation. The data suggest that the transport role of the SITs is relatively minor under conditions with sufficient silicic acid. Their primary role is to sense silicic acid levels to evaluate whether the cell can proceed with its cell wall formation and division processes. PMID:25380754

  15. Control of chitin nanofiber production by the lipid-producing diatom Cyclotella Sp. through fed-batch addition of dissolved silicon and nitrate in a bubble-column photobioreactor.

    Science.gov (United States)

    Chiriboga N, Omar G; Rorrer, Gregory L

    2017-03-01

    Diatoms are single-celled algae that make cell walls of nanopatterned biogenic silica called frustules through metabolic uptake of dissolved silicon and its templated condensation into biosilica. The centric marine diatom Cyclotella sp. also produces intracellular lipids and the valued coproduct chitin, an N-acetyl glucosamine biopolymer that is extruded from selected frustule pores as pure nanofibers. The goal of this study was to develop a nutrient feeding strategy to control the production of chitin nanofibers from Cyclotella with the coproduction of biofuel lipids. A two-stage phototrophic cultivation process was developed where Stage I set the cell suspension to a silicon-starved state under batch operation, and Stage II continuously added silicon and nitrate to the silicon-starved cells to enable one more cell doubling to 4 × 106 cells mL-1 . The silicon delivery rate was set to enable a silicon-limited cell division rate under cumulative delivery of 0.8 mM Si and 1.2 mM nitrate (1.5:1 mol N/mol Si) over a 4- to 14-day addition period. In Stage II, both cell number and chitin production were linear with time. Cell number and the specific chitin production rate increased linearly with increasing silicon delivery rate to achieve cumulative product yields of 13 ± 1 mg chitin/109 cells and 33 ± 3 mg lipid/109 cells. Therefore, chitin production is controlled through cell division, which is externally controlled through silicon delivery. Lipid production was not linearly correlated to silicon delivery and occurred primarily during Stage I, just after the complete co-consumption of both dissolved silicon and nitrate. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:407-415, 2017. © 2017 American Institute of Chemical Engineers.

  16. 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.)

  17. Atomic-layer deposition of silicon nitride

    CERN Document Server

    Yokoyama, S; Ooba, K

    1999-01-01

    Atomic-layer deposition (ALD) of silicon nitride has been investigated by means of plasma ALD in which a NH sub 3 plasma is used, catalytic ALD in which NH sub 3 is dissociated by thermal catalytic reaction on a W filament, and temperature-controlled ALD in which only a thermal reaction on the substrate is employed. The NH sub 3 and the silicon source gases (SiH sub 2 Cl sub 2 or SiCl sub 4) were alternately supplied. For all these methods, the film thickness per cycle was saturated at a certain value for a wide range of deposition conditions. In the catalytic ALD, the selective deposition of silicon nitride on hydrogen-terminated Si was achieved, but, it was limited to only a thin (2SiO (evaporative).

  18. Characterization of optical active nanostructures on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Baumgaertel, Thomas; Graaf, Harald; Borczyskowski, Christian von [Center of Nanostructured Materials and Analytics, TU Chemnitz (Germany)

    2008-07-01

    It has been recently demonstrated, that nanostructures can be functionalized in a neat way through selective binding of dye molecules and nanoparticles. Anchoring optically active molecules on nanostructured surfaces is a promising step towards building complex structures with variable properties and functions. In our contribution we report on the characterization of nanostructures on silicon, that have been optically functionalized by binding of cationic dyes. The structures have been generated by local anodic oxidation of alkyl-terminated silicon via AFM. Due to the oxidation process, these silicon oxide structures are partially negatively charged. The cationic dyes rhodamine 6G and cresyl violet have been attached to the structures via electrostatic interactions and were studied using wide-field and confocal microscopy. A change in luminescence spectra of the dyes on the nanostructures, compared to the dyes in solution has been found. Furthermore, the bleaching behaviour of the dyes bound to the structure has been investigated.

  19. Compound FDTD method for silicon photonics

    Directory of Open Access Journals (Sweden)

    Abbas Olyaee

    2011-09-01

    Full Text Available Attempt to manufacture photonics devices on silicon requires theoretical and numerical prediction. This essay presents Compound FDTD (C-FDTD method for comprehensive simulation of silicon photonics devices. Although this method is comprehensive, it maintains conventional Yee algorithm. The method involves variation of refractive index due to nonlinear effects. With the help of this simulator, refractive index change due to free-carriers created through two photon absorption and Kerr effect in silicon waveguide is considered. Results indicate how to choose pump pulse shape to optimum operation of active photonics devices. Also conductivity variation of Si waveguide due to change in free-carrier density is studied. By considering variations in conductivity profile, we are able to design better schemes for sweep free carriers away with reverse bias or nonlinear photovoltaic effect for fast devices and Raman amplifiers.

  20. Mechanical Properties of Silicon Carbonitride Thin Films

    Science.gov (United States)

    Peng, Xiaofeng; Hu, Xingfang; Wang, Wei; Song, Lixin

    2003-02-01

    Silicon carbonitride thin films were synthesized by reactive rf sputtering a silicon carbide target in nitrogen and argon atmosphere, or sputtering a silicon nitride target in methane and argon atmosphere, respectively. The Nanoindentation technique (Nanoindenter XP system with a continuous stiffness measurement technique) was employed to measure the hardness and elastic modulus of thin films. The effects of sputtering power on the mechanical properties are different for the two SiCN thin films. With increasing sputtering power, the hardness and the elastic modulus decrease for the former but increase for the latter. The tendency is similar to the evolution trend of Si-C bonds in SiCN materials. This reflects that Si-C bonds provide greater hardness for SiCN thin films than Si-N and C-N bonds.