WorldWideScience

Sample records for high silicon content

  1. Denuded zone in Czochralski silicon wafer with high carbon content

    International Nuclear Information System (INIS)

    Chen Jiahe; Yang Deren; Ma Xiangyang; Que Duanlin

    2006-01-01

    The thermal stability of the denuded zone (DZ) created by high-low-high-temperature annealing in high carbon content (H[C]) and low carbon content (L[C]) Czochralski silicon (Cz-Si) has been investigated in a subsequent ramping and isothermal 1050 deg. C annealing. The tiny oxygen precipitates which might occur in the DZ were checked. It was found in the L[C] Cz-Si that the DZ shrank and the density of bulk micro-defects (BMDs) reduced with the increase of time spent at 1050 deg. C. Also, the DZs above 15 μm of thickness present in the H[C] Cz-Si wafers continuously and the density and total volume of BMDs first decreased then increased and finally decreased again during the treatments. Moreover, tiny oxygen precipitates were hardly generated inside the DZs, indicating that H[C] Cz-Si wafers could support the fabrication of integrated circuits

  2. Denuded zone in Czochralski silicon wafer with high carbon content

    Science.gov (United States)

    Chen, Jiahe; Yang, Deren; Ma, Xiangyang; Que, Duanlin

    2006-12-01

    The thermal stability of the denuded zone (DZ) created by high-low-high-temperature annealing in high carbon content (H[C]) and low carbon content (L[C]) Czochralski silicon (Cz-Si) has been investigated in a subsequent ramping and isothermal 1050 °C annealing. The tiny oxygen precipitates which might occur in the DZ were checked. It was found in the L[C] Cz-Si that the DZ shrank and the density of bulk micro-defects (BMDs) reduced with the increase of time spent at 1050 °C. Also, the DZs above 15 µm of thickness present in the H[C] Cz-Si wafers continuously and the density and total volume of BMDs first decreased then increased and finally decreased again during the treatments. Moreover, tiny oxygen precipitates were hardly generated inside the DZs, indicating that H[C] Cz-Si wafers could support the fabrication of integrated circuits.

  3. Effect of Si content on fatigue fracture behavior of hot-rolled high-silicon steels

    Science.gov (United States)

    Umezawa, Osamu; Kanda, Jyunichi; Yamazaki, Takao

    2017-05-01

    As the Si content was increased from 1.5 to 5 mass%, both the yield stress and ultimate tensile strength were increased, respectively. The work hardening rate was also increased as the increase of Si content. On the contrary, the elongation was decreased as the increase of Si content, and the fracture manner was shifted from ductile to brittle. The 107 cycles fatigue strength was higher as the increase of Si content. The small misorientation distribution as ladder-like was detected in the grains of 1.5 mass%Si steel. Around the grain boundary, the strain incompatibility was detected in the steels containing over 3 mass%Si. The lattice rotation was locally detected in the vicinity of grain boundaries.

  4. The effect of silicon content on high temperature oxidation of 80Ni-20Cr alloys

    International Nuclear Information System (INIS)

    Takei, Atsushi; Nii, Kazuyoshi

    1981-01-01

    The effect of Si content on the oxidation behavior of 80Ni-20Cr alloys has been studied in the cyclic oxidation in an air stream at 1373K. The addition of 1% and 5%Si to the alloy lowered the mass gain in oxidation, whereas the amount of spalling of oxide scale was increased with the addition of Si. The structure of oxide layers observed by microphotography, X-ray diffraction and electron probe microanalysis (EPMA) were different with the Si content of alloys. The oxide layer of the alloy with 1%Si consists of multi-layers, that is Ni oxide, Cr 2 O 3 and SiO 2 as the external oxide layer. The oxide layer remaining on the alloy with 5%Si, however, was made of a single oxide layer of Cr 2 O 3 containing small amounts of Si and Ni. In spite of the fact that the amount of Si in this alloy is larger than that of the alloy with 1%Si, the SiO 2 oxide layer was not observed at the oxide-alloy interface. It was found by EPMA that the concentration of Si in the oxidized 5%Si alloy substrate was increased in the vicinity of the surface, although Si in the 1%Si alloy was depleted. From the above results the internal oxidation of Si is assumed in the near-surface region of the 5%Si alloy. The internal oxidation of the 5%Si alloy was confirmed by an increase in hardness in the near-surface region. The difference in oxidation behavior between the 1%Si and 5%Si alloys can be understood under the assumption that the oxide layer formed of the 5%Si alloy contained much larger amounts of Ni and Si than that on the 1%Si alloy, and that this oxide layer tends to crack more easily, thus being less protective for the penetration of oxygen. (author)

  5. Varying temperature and silicon content in nanodiamond growth: effects on silicon-vacancy centres.

    Science.gov (United States)

    Choi, Sumin; Leong, Victor; Davydov, Valery A; Agafonov, Viatcheslav N; Cheong, Marcus W O; Kalashnikov, Dmitry A; Krivitsky, Leonid A

    2018-02-28

    Nanodidamonds containing colour centres open up many applications in quantum information processing, metrology, and quantum sensing. However, controlling the synthesis of nanodiamonds containing silicon vacancy (SiV) centres is still not well understood. Here we study nanodiamonds produced by a high-pressure high-temperature method without catalyst metals, focusing on two samples with clear SiV signatures. Different growth temperatures and relative content of silicon in the initial compound between the samples altered their nanodiamond size distributions and abundance of SiV centres. Our results show that nanodiamond growth can be controlled and optimised for different applications.

  6. The origin of high silicon content in potentially medicinal groundwater of Gran Canaria (Canary Islands, Spain. Modelling of chemical water-rock interactions

    Directory of Open Access Journals (Sweden)

    Dobrzyński, Dariusz

    2012-11-01

    Full Text Available Groundwater of Gran Canaria (Canary Island, Spain have been appreciated and used as an element of health tourism since the 19th Century. This activity was abandoned in the second half of 20th Century when springs disappeared due to groundwater drawdown. The chemistry of groundwater from 19 intakes in volcanic rocks of the north part of Gran Canaria was studied by applying geochemical modelling for quantifying processes responsible for high Si concentrations.Studied groundwater has temperature of 16.3°C–25.5°C, pH of 4.40–7.40, and usually HCO3-(Cl-Mg-Ca-Na hydrochemical types. At near-neutral pH, fresh groundwater usually has 0.1-0.3 mM of Si. In studied groundwater Si concentrations are 0.42 to 1.82 mM, and show positive correlation with ionic strength and temperature. Volcanic bedrocks consist of, generally, easily reactive silicate minerals. Weathering is not supported by low rainfall; however, it shall be intensified by high influx of salts from marine aerosols and lithogenic carbon dioxide into groundwater. Geochemical modelling has found water-mineral reactions which reflect properly diversity of bedrock mineralogy. Based on those chemical reactions, contributions of particular silicate minerals to the pool of silicon dissolved in groundwater were calculated. Understanding the processes responsible for water chemistry might help in proper management and protection of groundwater.The Si-rich waters might be found in numerous places of Gran Canaria in all volcanic rocks. Silicic acid is the only form of silicon which is biologically available, and is regarded as a component which provides balneotherapeutic benefits. Many studies have showed beneficial and essential aspects of silicon in humans. Studied groundwater from Gran Canaria has an unexploited balneotherapeutic potential, and due to very high Si contents they seem to be ideal for testing the health benefits of such waters to humans. Hydrogeochemical methods, including

  7. 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.

  8. Silicon alleviates salt stress, decreases malondialdehyde content ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-20

    Apr 20, 2009 ... growth and quality of cut flower miniature rose 'Pinocchio' in the rockwool culture ..... Gibberellins are a group of naturally occurring plant hormones that affect .... Effects of silicon on tolerance to water deficit and heat stress in ...

  9. Effect of silicon content and defects on the lifetime of ductile cast iron

    Directory of Open Access Journals (Sweden)

    Alhussein Akram

    2014-06-01

    Full Text Available In this work, the influence of microstructure on the mechanical properties has been studied for different grades of ferritic ductile cast iron. Mechanical tests were carried out and the effect of silicon on the resistance of material was well noticed. An increasing silicon content increases the strength and decreases the ductility of material. The lifetime and endurance limit of material were affected by the presence of defects in material and microstructure heterogeneity. Metallurgical characterizations showed that the silicon was highly segregated around graphite nodules which leads to the initiation of cracks. The presence of defects causes the stress concentration and leads to the initiation and propagation of cracks.

  10. High yield silicon carbide prepolymers

    International Nuclear Information System (INIS)

    Baney, R.H.

    1982-01-01

    Prepolymers which exhibit good handling properties, and are useful for preparing ceramics, silicon carbide ceramic materials and articles containing silicon carbide, are polysilanes consisting of 0 to 60 mole% (CH 3 ) 2 Si units and 40 to 100 mole% CH 3 Si units, all Si valences being satisfied by CH 3 groups, other Si atoms, or by H atoms, the latter amounting to 0.3 to 2.1 weight% of the polysilane. They are prepared by reducing the corresponding chloro- or bromo-polysilanes with at least the stoichiometric amount of a reducing agent, e.g. LiAlH 4 . (author)

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

    Science.gov (United States)

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

    2013-07-29

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

  12. High-density oxidized porous silicon

    International Nuclear Information System (INIS)

    Gharbi, Ahmed; Souifi, Abdelkader; Remaki, Boudjemaa; Halimaoui, Aomar; Bensahel, Daniel

    2012-01-01

    We have studied oxidized porous silicon (OPS) properties using Fourier transform infraRed (FTIR) spectroscopy and capacitance–voltage C–V measurements. We report the first experimental determination of the optimum porosity allowing the elaboration of high-density OPS insulators. This is an important contribution to the research of thick integrated electrical insulators on porous silicon based on an optimized process ensuring dielectric quality (complete oxidation) and mechanical and chemical reliability (no residual pores or silicon crystallites). Through the measurement of the refractive indexes of the porous silicon (PS) layer before and after oxidation, one can determine the structural composition of the OPS material in silicon, air and silica. We have experimentally demonstrated that a porosity approaching 56% of the as-prepared PS layer is required to ensure a complete oxidation of PS without residual silicon crystallites and with minimum porosity. The effective dielectric constant values of OPS materials determined from capacitance–voltage C–V measurements are discussed and compared to FTIR results predictions. (paper)

  13. High damage tolerance of electrochemically lithiated silicon

    Science.gov (United States)

    Wang, Xueju; Fan, Feifei; Wang, Jiangwei; Wang, Haoran; Tao, Siyu; Yang, Avery; Liu, Yang; Beng Chew, Huck; Mao, Scott X.; Zhu, Ting; Xia, Shuman

    2015-01-01

    Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. Here we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries. PMID:26400671

  14. High-efficient solar cells with porous silicon

    International Nuclear Information System (INIS)

    Migunova, A.A.

    2002-01-01

    It has been shown that the porous silicon is multifunctional high-efficient coating on silicon solar cells, modifies its surface and combines in it self antireflection and passivation properties., The different optoelectronic effects in solar cells with porous silicon were considered. The comparative parameters of uncovered photodetectors also solar cells with porous silicon and other coatings were resulted. (author)

  15. A study on the effect of silicon content on mechanical properties

    International Nuclear Information System (INIS)

    Kwon, C.T.; Nam, T.W.; Lee, S.I.

    1978-01-01

    In Al-Si alloy, the variation of mechanical properties with silicon contents was investigated the silicon content being varied from 5% to 25%, and the effects of additives and refining elements were also studied. The results obtained are as follows: 1) Sodium treatment made the primary silicon crystals refined and spheroidized, and made the matrix structure intensified. The effect of P treatment on refining primary silicon crystals was greater then that of Na. 2) Tensile strength showed the maximum value at near the eutectic composition and was improved considerably by addition of Mg and treatment with Na. 3) The variation of matrix hardness with silicon contents was not perceptible and the hardness was improved by addition of Mg and treatment with Na. (author)

  16. Amorphous silicon as high index photonic material

    Science.gov (United States)

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

    2009-05-01

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

  17. Nuclear radiation detectors using high resistivity neutron transmutation doped silicon

    International Nuclear Information System (INIS)

    Gessner, T.; Irmer, K.

    1983-01-01

    A method for the production of semiconductor detectors based on high resistivity n-type silicon is described. The n-type silicon is produced by neutron irradiation of p-type silicon. The detectors are produced by planar technique. They are suitable for the spectrometry of alpha particles and for the pulse count measurement of beta particles at room temperature. (author)

  18. 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

  19. 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...

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

    Science.gov (United States)

    Buriak, Jillian M

    2006-01-15

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

  1. Talc-silicon glass-ceramic waste forms for immobilization of high- level calcined waste

    International Nuclear Information System (INIS)

    Vinjamuri, K.

    1993-06-01

    Talc-silicon glass-ceramic waste forms are being evaluated as candidates for immobilization of the high level calcined waste stored onsite at the Idaho Chemical Processing Plant. These glass-ceramic waste forms were prepared by hot isostatically pressing a mixture of simulated nonradioactive high level calcined waste, talc, silicon and aluminum metal additives. The waste forms were characterized for density, chemical durability, and glass and crystalline phase compositions. The results indicate improved density and chemical durability as the silicon content is increased

  2. High-performance silicon nanowire bipolar phototransistors

    Science.gov (United States)

    Tan, Siew Li; Zhao, Xingyan; Chen, Kaixiang; Crozier, Kenneth B.; Dan, Yaping

    2016-07-01

    Silicon nanowires (SiNWs) have emerged as sensitive absorbing materials for photodetection at wavelengths ranging from ultraviolet (UV) to the near infrared. Most of the reports on SiNW photodetectors are based on photoconductor, photodiode, or field-effect transistor device structures. These SiNW devices each have their own advantages and trade-offs in optical gain, response time, operating voltage, and dark current noise. Here, we report on the experimental realization of single SiNW bipolar phototransistors on silicon-on-insulator substrates. Our SiNW devices are based on bipolar transistor structures with an optically injected base region and are fabricated using CMOS-compatible processes. The experimentally measured optoelectronic characteristics of the SiNW phototransistors are in good agreement with simulation results. The SiNW phototransistors exhibit significantly enhanced response to UV and visible light, compared with typical Si p-i-n photodiodes. The near infrared responsivities of the SiNW phototransistors are comparable to those of Si avalanche photodiodes but are achieved at much lower operating voltages. Compared with other reported SiNW photodetectors as well as conventional bulk Si photodiodes and phototransistors, the SiNW phototransistors in this work demonstrate the combined advantages of high gain, high photoresponse, low dark current, and low operating voltage.

  3. Determination of aluminium, silicon and magnesium content in water samples by nuclear physical methods using XRFA and the MT-25 microtron

    International Nuclear Information System (INIS)

    Maslov, O.D.; Gustova, M.V.; Belov, A.G.; Drobina, T.P.

    2011-01-01

    Some of element contents in the samples have been determined by nuclear physical methods (XRFA, GAA and NAA). The possibility of determining Al, Si and Mg content in water samples has been studied. The detection limits of 0.03 mg/1 for Al, 0.3 mg/1 for Si and 0.1 mg/1 for Mg in water samples have been obtained. Monitoring of the aluminium and silicon content in water is important because the high concentration of aluminium or the low content of silicon in drinking water may be risk factors for Alzheimer's disease

  4. Catastrophic degradation of the interface of epitaxial silicon carbide on silicon at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepkumar, Aiswarya; Mishra, Neeraj; Kermany, Atieh Ranjbar; Iacopi, Francesca [Queensland Micro and Nanotechnology Centre and Environmental Futures Research Institute, Griffith University, Nathan QLD 4111 (Australia); Boeckl, John J. [Materials and Manufacturing Directorate, Air Force Research Laboratories, Wright-Patterson Air Force Base, Ohio 45433 (United States); Hellerstedt, Jack; Fuhrer, Michael S. [Monash Centre for Atomically Thin Materials, Monash University, Monash, VIC 3800 (Australia)

    2016-07-04

    Epitaxial cubic silicon carbide on silicon is of high potential technological relevance for the integration of a wide range of applications and materials with silicon technologies, such as micro electro mechanical systems, wide-bandgap electronics, and graphene. The hetero-epitaxial system engenders mechanical stresses at least up to a GPa, pressures making it extremely challenging to maintain the integrity of the silicon carbide/silicon interface. In this work, we investigate the stability of said interface and we find that high temperature annealing leads to a loss of integrity. High–resolution transmission electron microscopy analysis shows a morphologically degraded SiC/Si interface, while mechanical stress measurements indicate considerable relaxation of the interfacial stress. From an electrical point of view, the diode behaviour of the initial p-Si/n-SiC junction is catastrophically lost due to considerable inter-diffusion of atoms and charges across the interface upon annealing. Temperature dependent transport measurements confirm a severe electrical shorting of the epitaxial silicon carbide to the underlying substrate, indicating vast predominance of the silicon carriers in lateral transport above 25 K. This finding has crucial consequences on the integration of epitaxial silicon carbide on silicon and its potential applications.

  5. High temperature deformation of silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Calvillo, Pablo, E-mail: pablo.rodriguez@ctm.com.es [CTM - Technologic Centre, Materials Technology Area, Manresa, Cataluna (Spain); Department of Materials Science and Metallurgical Engineering, Universidad Politecnica de Cataluna, Barcelona (Spain); Houbaert, Yvan, E-mail: Yvan.Houbaert@UGent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Petrov, Roumen, E-mail: Roumen.Petrov@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Kestens, Leo, E-mail: Leo.kestens@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Colas, Rafael, E-mail: rafael.colas@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico)

    2012-10-15

    The microstructure and texture development during high temperature plane strain compression of 2% in weight silicon steel was studied. The tests were carried out at a constant strain rate of 5 s{sup -1} with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 Degree-Sign C. The changes in microstructure and texture were studied by means of scanning electron microscopy and electron backscattered diffraction. The microstructure close to the surface of the samples was equiaxed, which is attributed to the shear caused by friction, whereas that at the centre of the specimens was made of a mixture of elongated and fine equiaxed grains, the last ones attributed to the action of dynamic recovery followed by recrystallization. It was found that the volume fraction of these equiaxed grains augmented as reduction and temperature increased; a 0.7 volume fraction was accomplished with a 75% reduction at 1100 Degree-Sign C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the {gamma}-fibre tends to disappear and the {alpha}-fibre to increase towards the higher temperature range. -- Highlights: Black-Right-Pointing-Pointer The plastic deformation of a silicon containing steel is studied by plane strain compression. Black-Right-Pointing-Pointer Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. Black-Right-Pointing-Pointer Texture, by EBSD, is revealed to be similar in either type of grains.

  6. High temperature deformation of silicon steel

    International Nuclear Information System (INIS)

    Rodríguez-Calvillo, Pablo; Houbaert, Yvan; Petrov, Roumen; Kestens, Leo; Colás, Rafael

    2012-01-01

    The microstructure and texture development during high temperature plane strain compression of 2% in weight silicon steel was studied. The tests were carried out at a constant strain rate of 5 s −1 with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 °C. The changes in microstructure and texture were studied by means of scanning electron microscopy and electron backscattered diffraction. The microstructure close to the surface of the samples was equiaxed, which is attributed to the shear caused by friction, whereas that at the centre of the specimens was made of a mixture of elongated and fine equiaxed grains, the last ones attributed to the action of dynamic recovery followed by recrystallization. It was found that the volume fraction of these equiaxed grains augmented as reduction and temperature increased; a 0.7 volume fraction was accomplished with a 75% reduction at 1100 °C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the γ-fibre tends to disappear and the α-fibre to increase towards the higher temperature range. -- Highlights: ► The plastic deformation of a silicon containing steel is studied by plane strain compression. ► Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. ► Texture, by EBSD, is revealed to be similar in either type of grains.

  7. Production of high specific activity silicon-32

    International Nuclear Information System (INIS)

    Phillips, D.R.; Brzezinski, M.A.

    1998-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development Project (LDRD) at Los Alamos National Laboratory (LANL). There were two primary objectives for the work performed under this project. The first was to take advantage of capabilities and facilities at Los Alamos to produce the radionuclide 32 Si in unusually high specific activity. The second was to combine the radioanalytical expertise at Los Alamos with the expertise at the University of California to develop methods for the application of 32 Si in biological oceanographic research related to global climate modeling. The first objective was met by developing targetry for proton spallation production of 32 Si in KCl targets and chemistry for its recovery in very high specific activity. The second objective was met by developing a validated field-useable, radioanalytical technique, based upon gas-flow proportional counting, to measure the dynamics of silicon uptake by naturally occurring diatoms

  8. Microcapillary Features in Silicon Alloyed High-Strength Cast Iron

    Directory of Open Access Journals (Sweden)

    R.K. Hasanli

    2017-04-01

    Full Text Available Present study explores features of silicon micro capillary in alloyed high-strength cast iron with nodular graphite (ductile iron produced in metal molds. It identified the nature and mechanism of micro liquation of silicon in a ductile iron alloyed with Nickel and copper, and demonstrated significant change of structural-quality characteristics. It was concluded that the matrix of alloyed ductile iron has a heterogeneous structure with cross reinforcement and high-silicon excrement areas.

  9. Effect of Liquid Phase Content on Thermal Conductivity of Hot-Pressed Silicon Carbide Ceramics

    International Nuclear Information System (INIS)

    Lim, Kwang-Young; Jang, Hun; Lee, Seung-Jae; Kim, Young-Wook

    2015-01-01

    Silicon carbide (SiC) is a promising material for Particle-Based Accident Tolerant (PBAT) fuel, fission, and fusion power applications due to its superior physical and thermal properties such as low specific mass, low neutron cross section, excellent radiation stability, low coefficient of thermal expansion, and high thermal conductivity. Thermal conductivity of PBAT fuel is one of very important factors for plant safety and energy efficiency of nuclear reactors. In the present work, the effect of Y 2 O 3 -Sc 2 O 3 content on the microstructure and thermal properties of the hot pressed SiC ceramics have been investigated. Suppressing the β to α phase transformation of SiC ceramics is beneficial in increasing the thermal conductivity of liquid-phase sintered SiC ceramics. Developed SiC ceramics with Y 2 O 3 -Sc 2 O 3 additives are very useful for thermal conductivity on matrix material of the PBAT fuel

  10. High Detectivity Graphene-Silicon Heterojunction Photodetector.

    Science.gov (United States)

    Li, Xinming; Zhu, Miao; Du, Mingde; Lv, Zheng; Zhang, Li; Li, Yuanchang; Yang, Yao; Yang, Tingting; Li, Xiao; Wang, Kunlin; Zhu, Hongwei; Fang, Ying

    2016-02-03

    A graphene/n-type silicon (n-Si) heterojunction has been demonstrated to exhibit strong rectifying behavior and high photoresponsivity, which can be utilized for the development of high-performance photodetectors. However, graphene/n-Si heterojunction photodetectors reported previously suffer from relatively low specific detectivity due to large dark current. Here, by introducing a thin interfacial oxide layer, the dark current of graphene/n-Si heterojunction has been reduced by two orders of magnitude at zero bias. At room temperature, the graphene/n-Si photodetector with interfacial oxide exhibits a specific detectivity up to 5.77 × 10(13) cm Hz(1/2) W(-1) at the peak wavelength of 890 nm in vacuum, which is highest reported detectivity at room temperature for planar graphene/Si heterojunction photodetectors. In addition, the improved graphene/n-Si heterojunction photodetectors possess high responsivity of 0.73 A W(-1) and high photo-to-dark current ratio of ≈10(7) . The current noise spectral density of the graphene/n-Si photodetector has been characterized under ambient and vacuum conditions, which shows that the dark current can be further suppressed in vacuum. These results demonstrate that graphene/Si heterojunction with interfacial oxide is promising for the development of high detectivity photodetectors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Forming of nanocrystal silicon films by implantation of high dose of H+ in layers of silicon on isolator and following fast thermal annealing

    International Nuclear Information System (INIS)

    Tyschenko, I.E.; Popov, V.P.; Talochkin, A.B.; Gutakovskij, A.K.; Zhuravlev, K.S.

    2004-01-01

    Formation of nanocrystalline silicon films during rapid thermal annealing of the high-dose H + ion implanted silicon-on-insulator structures was studied. It was found, that Si nanocrystals had formed alter annealings at 300-400 deg C, their formation being strongly limited by the hydrogen content in silicon and also by the annealing time. It was supposed that the nucleation of crystalline phase occurred inside the silicon islands between micropores. It is conditioned by ordering Si-Si bonds as hydrogen atoms are leaving their sites in silicon network. No coalescence of micropores takes place during the rapid thermal annealing at the temperatures up to ∼ 900 deg C. Green-orange photoluminescence was observed on synthesized films at room temperature [ru

  12. High speed all-silicon optical modulator

    International Nuclear Information System (INIS)

    Marris-Morini, Delphine; Le Roux, Xavier; Pascal, Daniel; Vivien, Laurent; Cassan, Eric; Fedeli, Jean Marc; Damlencourt, Jean Francois; Bouville, David; Palomo, Jose; Laval, Suzanne

    2006-01-01

    Electrorefractive effect is experimentally demonstrated in an all-silicon optical structure. A highly doped Si P + layer is embedded in the intrinsic region of a PIN diode integrated in a SOI waveguide. Holes are confined at equilibrium around the P + layer. By applying a reverse bias to the diode, electrical field sweeps the carriers out of the active region. Free carrier concentration variations are responsible for local refractive index variations leading to an effective index variation of the waveguide optical mode and to an optical absorption variation. As a figure of merit, the product V π L π , determined from the measured effective index variation, is equal to 3.1 V cm. Furthermore, the device performances have theoretically been investigated. Estimations show that V π L π as small as 1 V cm are feasible using optimized structures. Response times lower than 2 ps are predicted, which gives the possibility to achieve very high-speed modulation. Furthermore, a temperature increases from 300 to 400 K does not change the index variation amplitude, and despite the carrier mobility reduction, response times are still lower than 2 ps

  13. The effect of grain refinement and silicon content on grain formation in hypoeutectic Al-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.C.; Dahle, A.K.; StJohn, D.H.; Hutt, J.E.C. [Queensland Univ., Brisbane (Australia). Dept. of Mining, Minerals and Mater. Eng.

    1999-01-15

    The effect of increasing the amount of added grain refiner on grain size and morphology has been investigated for a range of hypoeutectic Al-Si alloys. The results show a transition in grain size at a silicon concentration of about 3 wt% in unrefined alloys; the grain size decreasing with silicon content before the transition, and increasing beyond the transition point. A change in morphology also occurs with increased silicon content. The addition of grain refiner leads to greater refinement for silicon contents below the transition point than for those contents above the transition point, while the transition point seems to remain unchanged. The slope of the grain size versus silicon content curve after the transition seems to be unaffected by the degree of grain refinement. The results are related to the competitive processes of nucleation and constitutional effects during growth and their impact on nucleation kinetics. (orig.) 13 refs.

  14. Hydrophilic functionalized silicon nanoparticles produced by high energy ball milling

    Science.gov (United States)

    Hallmann, Steffen

    The mechanochemical synthesis of functionalized silicon nanoparticles using High Energy Ball Milling (HEBM) is described. This method facilitates the fragmentation of mono crystalline silicon into the nanometer regime and the simultaneous surface functionalization of the formed particles. The surface functionalization is induced by the reaction of an organic liquid, such as alkynes and alkenes with reactive silicon sites. This method can be applied to form water soluble silicon nanoparticles by lipid mediated micelle formation and the milling in organic liquids containing molecules with bi-functional groups, such as allyl alcohol. Furthermore, nanometer sized, chloroalkyl functionalized particles can be synthesized by milling the silicon precursor in the presence of an o-chloroalkyne with either alkenes or alkynes as coreactants. This process allows tuning of the concentration of the exposed, alkyl linked chloro groups, simply by varying the relative amounts of the coreactant. The silicon nanoparticles that are formed serve as the starting point for a wide variety of chemical reactions, which may be used to alter the surface properties of the functionalized nanoparticles. Finally, the use of functionalized silicon particles for the production of superhydrophobic films is described. Here HEBM proves to be an efficient method to produce functionalized silicon particles, which can be deposited to form a stable coating exhibiting superhydrophobic properties. The hydrophobicity of the silicon film can be tuned by the milling time and thus the resulting surface roughness of the films.

  15. Influence of redox condition in iron, silicon and hydrogen contents of leached glass surface

    International Nuclear Information System (INIS)

    Manara, A.; Lanza, F.; Della Mea, G.; Rossi, C.; Salvagno, G.

    1984-01-01

    Surface analysis has been conducted on samples leached in a Sochlet apparatus at 100 0 C in the presence and in the absence of air. The XPS technique was applied to analyze the content of iron and silicon while the nuclear reaction method was utilized to analyze the content of hydrogen. Samples leached in argon atmosphere have shown a smaller content of iron and silicon with respect to the samples leached in air atmosphere. The H concentration has shown the same behavior. The results are discussed in terms of possible formation of iron compounds in the different redox condition and of their different stabilities and in terms of their efficiency in reducing exchange between Na + and H + ions. 11 references, 3 figures, 1 table

  16. The low-aluminium cast iron of reduced silicon content treated with cerium mischmetal

    Directory of Open Access Journals (Sweden)

    M. S. Soiński

    2008-07-01

    Full Text Available The work presents the effect of cerium mischmetal used in quantities of 0.1 and 0.2 wt-% and ferrosilicon used in quantities from 0.5% to 1.5% on the alloy matrix and the shape of graphite precipitates in the low-aluminium cast iron from seven heats, basing on the examination of its structure. The hypereutectic cast iron of the relatively high carbon content (4.0÷4.2% at the prior-to-treatment silicon and manganese content equal to ca. 0.6% and ca. 0.04%, respectively, has been examined.It has been found that the performed treatment leads to the change in the alloy matrix from the nearly almost pearlitic to the ferritic-pearlitic one accompanied by changes in the shape of graphite precipitates. Due to applying both of the mentioned substances in the above stated amounts the graphite precipitates in cast iron have taken the shape of nodular and vermicular ones, and no presence of flake graphite has been revealed. A quantitative analysis of the performed treatment i.e. determining the fractions of graphite precipitates of different shapes has been possible by means of a computer image analyser.

  17. Silicon Photomultiplier Performance in High ELectric Field

    Science.gov (United States)

    Montoya, J.; Morad, J.

    2016-12-01

    Roughly 27% of the universe is thought to be composed of dark matter. The Large Underground Xenon (LUX) relies on the emission of light from xenon atoms after a collision with a dark matter particle. After a particle interaction in the detector, two things can happen: the xenon will emit light and charge. The charge (electrons), in the liquid xenon needs to be pulled into the gas section so that it can interact with gas and emit light. This allows LUX to convert a single electron into many photons. This is done by applying a high voltage across the liquid and gas regions, effectively ripping electrons out of the liquid xenon and into the gas. The current device used to detect photons is the photomultiplier tube (PMT). These devices are large and costly. In recent years, a new technology that is capable of detecting single photons has emerged, the silicon photomultiplier (SiPM). These devices are cheaper and smaller than PMTs. Their performance in a high electric fields, such as those found in LUX, are unknown. It is possible that a large electric field could introduce noise on the SiPM signal, drowning the single photon detection capability. My hypothesis is that SiPMs will not observe a significant increase is noise at an electric field of roughly 10kV/cm (an electric field within the range used in detectors like LUX). I plan to test this hypothesis by first rotating the SiPMs with no applied electric field between two metal plates roughly 2 cm apart, providing a control data set. Then using the same angles test the dark counts with the constant electric field applied. Possibly the most important aspect of LUX, is the photon detector because it's what detects the signals. Dark matter is detected in the experiment by looking at the ratio of photons to electrons emitted for a given interaction in the detector. Interactions with a low electron to photon ratio are more like to be dark matter events than those with a high electron to photon ratio. The ability to

  18. Self-Healing, High-Permittivity Silicone Dielectric Elastomer

    DEFF Research Database (Denmark)

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

    2016-01-01

    possesses high dielectric permittivity and consists of an interpenetrating polymer network of silicone elastomer and ionic silicone species that are cross-linked through proton exchange between amines and acids. The ionically cross-linked silicone provides self-healing properties after electrical breakdown...... or cuts made directly to the material due to the reassembly of the ionic bonds that are broken during damage. The dielectric elastomers presented in this paper pave the way to increased lifetimes and the ability of dielectric elastomers to survive millions of cycles in high-voltage conditions....

  19. Effect of silicon contents on the microstructures and mechanical properties of heat affected zones for 9Cr2WVTa steels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 110016, Shenyang (China); Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Science, 110016, Shenyang (China); Lu, Shanping, E-mail: shplu@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 110016, Shenyang (China); Rong, Lijian [Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Science, 110016, Shenyang (China); Li, Dianzhong [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 110016, Shenyang (China)

    2016-03-15

    The weldability of 9Cr2WVTa steels with silicon content varying from 0.30 wt.% to 1.36 wt.% was studied to meet the requirement of Generation-Ⅳ nuclear reactor. Samples of enlarged HAZs were fabricated by a thermal-mechanical simulator based on the simulation and measurement of non-equilibrium phase transformation. The content of δ-ferrite in the HAZs increased with the silicon content and the peak temperature of welding thermal cycle. The impact toughness in the HAZs decreased in different degrees when the δ-ferrite exhibits stripe (lower than 4.82%) or blocky types (higher than 4.82%). Post weld heat treatment (PWHT) has a significant role on improving the toughness. Adding silicon content increased the volume of δ-ferrite and therefore, decreased the tensile strength of the HAZs for 9Cr2WVTa steels. Silicon also as solid solution strengthening element increased the tensile strength. The 9Cr2WVTa steel has good weldability when the silicon content is lower than 0.60 wt.%. - Highlights: • The weldability of 9Cr2WVTa steel with different silicon contents was studied. • The impact toughness decreased in different degrees owing to the δ-ferrite. • PWHT has a significant role on improving the impact toughness. • The 9Cr2WVTa steel with silicon content not exceeding 0.60 wt.% has good weldability.

  20. Ultra-high-speed Optical Signal Processing using Silicon Photonics

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

    with a photonic layer on top to interconnect them. For such systems, silicon is an attractive candidate enabling both electronic and photonic control. For some network scenarios, it may be beneficial to use optical on-chip packet switching, and for high data-density environments one may take advantage...... of the ultra-fast nonlinear response of silicon photonic waveguides. These chips offer ultra-broadband wavelength operation, ultra-high timing resolution and ultra-fast response, and when used appropriately offer energy-efficient switching. In this presentation we review some all-optical functionalities based...... on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show...

  1. Brain inspired high performance electronics on flexible silicon

    KAUST Repository

    Sevilla, Galo T.; Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa

    2014-01-01

    Brain's stunning speed, energy efficiency and massive parallelism makes it the role model for upcoming high performance computation systems. Although human brain components are a million times slower than state of the art silicon industry components

  2. Iron solubility in highly boron-doped silicon

    International Nuclear Information System (INIS)

    McHugo, S.A.; McDonald, R.J.; Smith, A.R.; Hurley, D.L.; Weber, E.R.

    1998-01-01

    We have directly measured the solubility of iron in high and low boron-doped silicon using instrumental neutron activation analysis. Iron solubilities were measured at 800, 900, 1000, and 1100thinsp degree C in silicon doped with either 1.5x10 19 or 6.5x10 14 thinspboronthinspatoms/cm 3 . We have measured a greater iron solubility in high boron-doped silicon as compared to low boron-doped silicon, however, the degree of enhancement is lower than anticipated at temperatures >800thinsp degree C. The decreased enhancement is explained by a shift in the iron donor energy level towards the valence band at elevated temperatures. Based on this data, we have calculated the position of the iron donor level in the silicon band gap at elevated temperatures. We incorporate the iron energy level shift in calculations of iron solubility in silicon over a wide range of temperatures and boron-doping levels, providing a means to accurately predict iron segregation between high and low boron-doped silicon. copyright 1998 American Institute of Physics

  3. Introduction of high oxygen concentrations into silicon wafers by high-temperature diffusion

    International Nuclear Information System (INIS)

    Casse, G.; Glaser, M.; Lemeilleur, F.; Ruzin, A.; Wegrzecki, M.

    1999-01-01

    The tolerance of silicon detectors to hadron irradiation can be improved by the introduction of a high concentration of oxygen into the starting material. High-resistivity Floating-Zone (FZ) silicon is required for detectors used in particle physics applications. A significantly high oxygen concentration (>10 17 atoms cm -3 ) cannot readily be achieved during the FZ silicon refinement. The diffusion of oxygen at elevated temperatures from a SiO 2 layer grown on both sides of a silicon wafer is a simple and effective technique to achieve high and uniform concentrations of oxygen throughout the bulk of a 300 μm thick silicon wafer

  4. Process development for high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.

    1991-12-31

    Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.

  5. High frequency guided wave propagation in monocrystalline silicon wafers

    OpenAIRE

    Pizzolato, M.; Masserey, B.; Robyr, J. L.; Fromme, P.

    2017-01-01

    Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full...

  6. Just-in-Time Correntropy Soft Sensor with Noisy Data for Industrial Silicon Content Prediction.

    Science.gov (United States)

    Chen, Kun; Liang, Yu; Gao, Zengliang; Liu, Yi

    2017-08-08

    Development of accurate data-driven quality prediction models for industrial blast furnaces encounters several challenges mainly because the collected data are nonlinear, non-Gaussian, and uneven distributed. A just-in-time correntropy-based local soft sensing approach is presented to predict the silicon content in this work. Without cumbersome efforts for outlier detection, a correntropy support vector regression (CSVR) modeling framework is proposed to deal with the soft sensor development and outlier detection simultaneously. Moreover, with a continuous updating database and a clustering strategy, a just-in-time CSVR (JCSVR) method is developed. Consequently, more accurate prediction and efficient implementations of JCSVR can be achieved. Better prediction performance of JCSVR is validated on the online silicon content prediction, compared with traditional soft sensors.

  7. Functional silicone copolymers and elastomers with high dielectric permittivity

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Daugaard, Anders Egede; Hvilsted, Søren

    Dielectric elastomers (DEs) are a new and promising transducer technology and are often referred to as ‘artificial muscles’, due to their ability to undergo large deformations when stimulated by electric fields. DEs consist of a soft and thin elastomeric film sandwiched between compliant electrodes......, thereby forming a capacitor [1]. Silicone elastomers are one of the most used materials for DEs due to their high efficiency, fast response times and low viscous losses. The major disadvantage of silicone elastomers is that they possess relatively low dielectric permittivity, which means that a high...... electrical field is necessary to operate the DE. The necessary electrical field can be lowered by creating silicone elastomers with higher dielectric permittivity, i.e. with a higher energy density.The aim of this work is to create new and improved silicone elastomers with high dielectric permittivity...

  8. Development of large area, high efficiency amorphous silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K.S.; Kim, S.; Kim, D.W. [Yu Kong Taedok Institute of Technology (Korea, Republic of)

    1996-02-01

    The objective of the research is to develop the mass-production technologies of high efficiency amorphous silicon solar cells in order to reduce the costs of solar cells and dissemination of solar cells. Amorphous silicon solar cell is the most promising option of thin film solar cells which are relatively easy to reduce the costs. The final goal of the research is to develop amorphous silicon solar cells having the efficiency of 10%, the ratio of light-induced degradation 15% in the area of 1200 cm{sup 2} and test the cells in the form of 2 Kw grid-connected photovoltaic system. (author) 35 refs., 8 tabs., 67 figs.

  9. Corrosion of silicon nitride in high temperature alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liyan, E-mail: liyan.qiu@cnl.ca; Guzonas, Dave A.; Qian, Jing

    2016-08-01

    The corrosion of silicon nitride (Si{sub 3}N{sub 4}) in alkaline solutions was studied at temperatures from 60 to 300 °C. Si{sub 3}N{sub 4} experienced significant corrosion above 100 °C. The release rates of silicon and nitrogen follow zero order reaction kinetics and increase with increasing temperature. The molar ratio of dissolved silicon and nitrogen species in the high temperature solutions is the same as that in the solid phase (congruent dissolution). The activation energy for silicon and nitrogen release rates is 75 kJ/mol which agrees well with that of silica dissolution. At 300 °C, the release of aluminum is observed and follows first order reaction kinetics while other minor constituents including Ti and Y are highly enriched on the corrosion films due to the low solubility of their oxides.

  10. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Martini, R., E-mail: roberto.martini@imec.be [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Kepa, J.; Stesmans, A. [Department of Physics, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven (Belgium); Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Poortmans, J. [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Universiteit Hasselt, Martelarenlaan 42, B-3500 Hasselt (Belgium)

    2014-10-27

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  11. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    International Nuclear Information System (INIS)

    Martini, R.; Kepa, J.; Stesmans, A.; Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I.; Poortmans, J.

    2014-01-01

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  12. Influence of silicon content and heat treatment on wear resistance of white chromium cast irons under high speed solidification conditions; Influencia del contenido de silicio y el tratamiento termico en la resistencia al desgaste de fundiciones blancas al cromo en condiciones de rapida solidificacion

    Energy Technology Data Exchange (ETDEWEB)

    Goyo, L.; Varela, A.; Verhaege, M.; Garcia, A.; Mier, J.; Moors, M.

    2012-11-01

    The influence of silicon content and heat treatment on microstructure, abrasive and dry friction wear resistance of a 3 % C, 12 % Cr cast iron, under fast solidification conditions is studied. The fast solidification condition diminishes the carbide volume and the silicon content increases their dispersion and finesses. All matrixes obtained were perlitics, whit different finesses. No intermediate transformation products were noticed. Hardness had little variation. Austenization treatment show little effectivity, with tendency to increase wear in reference to as cast and maintenance treatments. Behavior under dry friction and abrasive wear were similar under test conditions applied whit more influence of carbide morphology in the abrasive wear conditions. (Author) 32 refs.

  13. High-gain bipolar detector on float-zone silicon

    Science.gov (United States)

    Han, D. J.; Batignani, G.; Del Guerra, A.; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

    2003-10-01

    Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ˜7.77×10 4/s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device.

  14. High-gain bipolar detector on float-zone silicon

    International Nuclear Information System (INIS)

    Han, D.J.; Batignani, G.; Guerra, A.D.A. Del; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

    2003-01-01

    Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ∼7.77x10 4 /s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device

  15. Controlling the Er content of porous silicon using the doping current intensity

    KAUST Repository

    Mula, Guido

    2014-07-04

    The results of an investigation on the Er doping of porous silicon are presented. Electrochemical impedance spectroscopy, optical reflectivity, and spatially resolved energy dispersive spectroscopy (EDS) coupled to scanning electron microscopy measurements were used to investigate on the transient during the first stages of constant current Er doping. Depending on the applied current intensity, the voltage transient displays two very different behaviors, signature of two different chemical processes. The measurements show that, for equal transferred charge and identical porous silicon (PSi) layers, the applied current intensity also influences the final Er content. An interpretative model is proposed in order to describe the two distinct chemical processes. The results can be useful for a better control over the doping process.

  16. Silicon-embedded copper nanostructure network for high energy storage

    Science.gov (United States)

    Yu, Tianyue

    2016-03-15

    Provided herein are nanostructure networks having high energy storage, electrochemically active electrode materials including nanostructure networks having high energy storage, as well as electrodes and batteries including the nanostructure networks having high energy storage. According to various implementations, the nanostructure networks have high energy density as well as long cycle life. In some implementations, the nanostructure networks include a conductive network embedded with electrochemically active material. In some implementations, silicon is used as the electrochemically active material. The conductive network may be a metal network such as a copper nanostructure network. Methods of manufacturing the nanostructure networks and electrodes are provided. In some implementations, metal nanostructures can be synthesized in a solution that contains silicon powder to make a composite network structure that contains both. The metal nanostructure growth can nucleate in solution and on silicon nanostructure surfaces.

  17. Silicon-embedded copper nanostructure network for high energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Tianyue

    2018-01-23

    Provided herein are nanostructure networks having high energy storage, electrochemically active electrode materials including nanostructure networks having high energy storage, as well as electrodes and batteries including the nanostructure networks having high energy storage. According to various implementations, the nanostructure networks have high energy density as well as long cycle life. In some implementations, the nanostructure networks include a conductive network embedded with electrochemically active material. In some implementations, silicon is used as the electrochemically active material. The conductive network may be a metal network such as a copper nanostructure network. Methods of manufacturing the nanostructure networks and electrodes are provided. In some implementations, metal nanostructures can be synthesized in a solution that contains silicon powder to make a composite network structure that contains both. The metal nanostructure growth can nucleate in solution and on silicon nanostructure surfaces.

  18. Super soft silicone elastomers with high dielectric permittivity

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Hvilsted, Søren

    2015-01-01

    Dielectric elastomers (DEs) have many favourable properties. The obstacle of high driving voltages, however, limits the commercial viability of the technology at present. Driving voltage can be lowered by decreasing the Young’s modulus and increasing the dielectric permittivity of silicone...... elastomers. A decrease in Young’s modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE. New soft elastomer matrices with high dielectric permittivity and low Young’s modulus, with no loss of mechanical stability, were prepared by two different...... approaches using chloropropyl-functional silicone polymers. The first approach was based on synthesised chloropropyl-functional copolymers that were cross-linkable and thereby formed the basis of new silicone networks with high dielectric permittivity (e.g. a 43% increase). These networks were soft without...

  19. Electromechanical stability of electro-active silicone filled with high permittivity particles undergoing large deformation

    International Nuclear Information System (INIS)

    Liu, Liwu; Liu, Yanju; Zhang, Zhen; Leng, Jinsong; Li, Bo

    2010-01-01

    In this paper, an expression for the permittivity of electro-active silicone undergoing large deformation with high permittivity particles filled uniformly has been proposed. Two expressions are proposed for the permittivity, one based on experimental tests and the other based on the theory of composite material. By applying the thermodynamic model incorporating linear dielectric permittivity and nonlinear hyperelastic performance, the mechanical performance and electromechanical stability of the coupling system constituted by silicone filled with PMN–PT have been studied. The results show that the critical electric field decreases, namely the stability performance of the system declines when the content of PMN–PT c(v) increases and the electrostrictive coefficients increase. The results are beneficial for us to understand deeply the influence of the filled particle on the stability performance of silicone and to guide the design and manufacture of actuators and sensors based on dielectric elastomers

  20. HIGH FREQUENCY INDUCTION WELDING OF HIGH SILICON STEEL TUBES

    Directory of Open Access Journals (Sweden)

    Ricardo Miranda Alé

    2012-06-01

    Full Text Available High-Si steel is a low cost alternative for the fabrication of tubular structures resistant to atmospheric corrosion. However, the literature has often pointed out that steels presenting a higher Si content and/or a lower Mn/Si ratio have higher susceptibility to defects at the weld bond line during HFIW (High Frequency Induction Welding process, which has been widely used for manufacturing small diameter tubes. In this study the effect of the HFIW conditions on the quality of steel tubes with high-Si content and low Mn/Si ratio is investigated. The quality of welded tubes was determined by flare test and the defects in the bond line were identified by SEM. It has been found that higher welding speeds, V-convergence angles and power input should be applied in welding of high-Si steel, when compared to similar strength C-Mn steel.

  1. High-Current-Density Vertical-Tunneling Transistors from Graphene/Highly Doped Silicon Heterostructures.

    Science.gov (United States)

    Liu, Yuan; Sheng, Jiming; Wu, Hao; He, Qiyuan; Cheng, Hung-Chieh; Shakir, Muhammad Imran; Huang, Yu; Duan, Xiangfeng

    2016-06-01

    Scalable fabrication of vertical-tunneling transistors is presented based on heterostructures formed between graphene, highly doped silicon, and its native oxide. Benefiting from the large density of states of highly doped silicon, the tunneling transistors can deliver a current density over 20 A cm(-2) . This study demonstrates that the interfacial native oxide plays a crucial role in governing the carrier transport in graphene-silicon heterostructures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Design of a charge sensitive preamplifier on high resistivity silicon

    International Nuclear Information System (INIS)

    Radeka, V.; Rehak, P.; Rescia, S.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Strueder, L.; Kemmer, J.

    1987-01-01

    A low noise, fast charge sensitive preamplifier was designed on high resistivity, detector grade silicon. It is built at the surface of a fully depleted region of n-type silicon. This allows the preamplifier to be placed very close to a detector anode. The preamplifier uses the classical input cascode configuration with a capacitor and a high value resistor in the feedback loop. The output stage of the preamplifier can drive a load up to 20pF. The power dissipation of the preamplifier is 13mW. The amplifying elements are ''Single Sided Gate JFETs'' developed especially for this application. Preamplifiers connected to a low capacitance anode of a drift type detector should achieve a rise time of 20ns and have an equivalent noise charge (ENC), after a suitable shaping, of less than 50 electrons. This performance translates to a position resolution better than 3μm for silicon drift detectors. 6 refs., 9 figs

  3. High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, H.

    2011-03-01

    Reported are the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Silicon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to complete the fabrication of the Silicon Ink high efficiency solar cells. Also reported are the development and demonstration of a 18.5% efficient 125mm x 125mm monocrystalline Silicon cell, and a 17% efficient 125mm x 125mm multicrystalline Silicon cell, by utilizing high throughput Ink-jet and screen printing technologies. To achieve these objectives, Innovalight developed new high throughput processing tools to print and fuse both p and n type particle Silicon Inks in a predetermined pat-tern applied either on the front or the back of the cell. Additionally, a customized Ink-jet and screen printing systems, coupled with customized substrate handling solution, customized printing algorithms, and a customized ink drying process, in combination with a purchased turn-key line, were used to complete the high efficiency solar cells. This development work delivered a process capable of high volume producing 18.5% efficient crystalline Silicon solar cells and enabled the Innovalight to commercialize its technology by the summer of 2010.

  4. Autoionizing states in highly ionized oxygen, fluorine and silicon

    International Nuclear Information System (INIS)

    Forester, J.P.; Peterson, R.S.; Griffin, P.M.; Pegg, D.J.; Haselton, H.H.; Liao, K.H.; Sellin, I.A.; Mowat, J.R.; Thoe, R.S.

    1975-01-01

    Autoionizing states in high Z 3-electron ions associated with core excited configurations of the type 1s2snl and 1s2pnl are reported. The electron decay-in-flight spectra of lithium-like oxygen, fluorine, and silicon ions are presented. Initial beam energies of 6.75-MeV oxygen and fluorine ions and 22.5-MeV silicon ions were used. Stripping and excitation were done by passing the beams through a thin carbon foil. The experimental technique is described. 4 figs, 1 table, 7 refs

  5. Simple processing of high efficiency silicon solar cells

    International Nuclear Information System (INIS)

    Hamammu, I.M.; Ibrahim, K.

    2006-01-01

    Cost effective photovoltaic devices have been an area research since the development of the first solar cells, as cost is the major factor in their usage. Silicon solar cells have the biggest share in the photovoltaic market, though silicon os not the optimal material for solar cells. This work introduces a simplified approach for high efficiency silicon solar cell processing, by minimizing the processing steps and thereby reducing cost. The suggested procedure might also allow for the usage of lower quality materials compared to the one used today. The main features of the present work fall into: simplifying the diffusion process, edge shunt isolation and using acidic texturing instead of the standard alkaline processing. Solar cells of 17% efficiency have been produced using this procedure. Investigations on the possibility of improving the efficiency and using less quality material are still underway

  6. High-Tc superconducting antenna-coupled microbolometer on silicon

    Science.gov (United States)

    Rice, Joseph P.; Grossman, Erich N.; Borcherdt, L. J.; Rudman, D. A.

    1994-05-01

    A process is described for fabricating antenna-coupled resistive-edge microbolometers based on the high-Tc superconductor YBa2Cu3O7 (YBCO) on silicon. The YBCO and a buffer layer of yttria-stabilized zirconia (YSZ) were grown epitaxially on silicon to minimize excess electrical noise. A silicon-micromachined YBCO/YSZ air-bridge was incorporated to minimize the thermal conductance and the heat capacity. The thermal conductance of the air-bridge was measured to be 3 X 10-6 W/K at a temperature of 100 K. At an operating temperature of 89 K, the detector is estimated to have a response time of 2 microsecond(s) , a responsivity of the 1000 V/W range, and a noise-equivalent power in the 10-12 W/Hz1/2 range at 1000 Hz.

  7. High-{Tc} superconducting antenna-coupled microbolometer on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Rice, J.P.; Grossman, E.N.; Borcherdt, L.J.; Rudman, D.A. [National Inst. of Standards and Technology, Boulder, CO (United States). Cryoelectronic Metrology Group

    1994-12-31

    A process is described for fabricating antenna-coupled resistive-edge microbolometers based on the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) on silicon. The YBCO and a buffer layer of yttria-stabilized zirconia (YSZ) were grown epitaxially on silicon to minimize excess electrical noise. A silicon-micromachined YBCO/YSZ air-bridge was incorporated to minimize the thermal conductance and the heat capacity. The thermal conductance of the air-bridge was measured to be 3 {times} 10{sup {minus}6} W/K at a temperature of 100 K. At an operating temperature of 89 K, the detector is estimated to have a response time of 2 {micro}s, a responsivity in the 1,000 V/W range, and a noise-equivalent power (NEP) in the 10{sup {minus}12} W/Hz{sup 1/2} range at 1,000 Hz.

  8. High-field EPR spectroscopy of thermal donors in silicon

    DEFF Research Database (Denmark)

    Dirksen, R.; Rasmussen, F.B.; Gregorkiewicz, T.

    1997-01-01

    Thermal donors generated in p-type boron-doped Czochralski-grown silicon by a 450 degrees C heat treatment have been studied by high-field magnetic resonance spectroscopy. In the experiments conducted at a microwave frequency of 140 GHz and in a magnetic field of approximately 5 T four individual...

  9. Suppressing segregation in highly phosphorus doped silicon monolayers

    NARCIS (Netherlands)

    Keizer, Joris; Kölling, Sebastian; Koenraad, Paul; Simmons, Michelle Y.

    2015-01-01

    Sharply defined dopant profiles and low resistivity are highly desired qualities in the microelectronic industry, and more recently, in the development of an all epitaxial Si:P based quantum computer. In this work, we use thin (monolayers thick) room temperature grown silicon layers, so-called

  10. Direct Electroplating on Highly Doped Patterned Silicon Wafers

    NARCIS (Netherlands)

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

    Nickel thin films have been electrodeposited directly on highly doped silicon wafers after removal of the native oxide layer. These substrates conduct sufficiently well to allow deposition using a periferical electrical contact on the wafer. Films 2 μm thick were deposited using a nickel sulfamate

  11. Process Characterization of Electrical Discharge Machining of Highly Doped Silicon

    Science.gov (United States)

    2012-06-01

    of mechanism is shown in Figure 2 showing the wire feed panel where the spool of 5 (DiBitonto, et...Uno High efficiency boring of monocrystalline silicon ingot by EDM RAM Si (P-type) conductivity 0.01 ohm-cm 1mm Cu pipe electrode, rotating at

  12. High power terahertz induced carrier multiplication in Silicon

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Pedersen, Pernille Klarskov; Iwaszczuk, Krzysztof

    2015-01-01

    The application of an intense THz field results a nonlinear transmission in high resistivity silicon. Upon increasing field strength, the transmission falls from 70% to 62% due to carrier generation through THz-induced impact ionization and subsequent absorption of the THz field by free electrons....

  13. Correlation Between Grain Size Distribution and Silicon and Oxygen Contents at Wadi Arar Sediments, Kingdom of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    M. A. M. Alghamdi

    2017-08-01

    Full Text Available Quartz is the major mineral of Wadi Arar sediments. The top two elements contents are oxygen with 63.96 wt%, followed by silicon with 16.35 wt%. There is a positive, weak to medium correlation between grain size and silicon and oxygen contents. The correlation between oxygen and grain size is four times higher than that of silicon. At grain size ranges between 0.8 and 1.0 mm, both oxygen and silicon show the maximum correlation, which decrease gradually with finer and coarser grain sizes. For each element, the correlation between the element content and grain size is a fourth degree polynomial in the grain size. Theoretically, the best two math models that represent the relation between the grain size distribution and each of individual oxygen and silicon content are y=8.84∙ln(x+39.5 and y=2.26∙ln(x+10.1 respectively, where y represents the element content percentage and x represents the corresponding grain size in mm.

  14. Linear and nonlinear characterization of low-stress high-confinement silicon-rich nitride waveguides.

    Science.gov (United States)

    Krückel, Clemens J; Fülöp, Attila; Klintberg, Thomas; Bengtsson, Jörgen; Andrekson, Peter A; Torres-Company, Víctor

    2015-10-05

    In this paper we introduce a low-stress silicon enriched nitride platform that has potential for nonlinear and highly integrated optics. The manufacturing process of this platform is CMOS compatible and the increased silicon content allows tensile stress reduction and crack free layer growth of 700 nm. Additional benefits of the silicon enriched nitride is a measured nonlinear Kerr coefficient n(2) of 1.4·10(-18) m(2)/W (5 times higher than stoichiometric silicon nitride) and a refractive index of 2.1 at 1550 nm that enables high optical field confinement allowing high intensity nonlinear optics and light guidance even with small bending radii. We analyze the waveguide loss (∼1 dB/cm) in a spectrally resolved fashion and include scattering loss simulations based on waveguide surface roughness measurements. Detailed simulations show the possibility for fine dispersion and nonlinear engineering. In nonlinear experiments we present continuous-wave wavelength conversion and demonstrate that the material does not show nonlinear absorption effects. Finally, we demonstrate microfabrication of resonators with high Q-factors (∼10(5)).

  15. Radiation hardened high efficiency silicon space solar cell

    International Nuclear Information System (INIS)

    Garboushian, V.; Yoon, S.; Turner, J.

    1993-01-01

    A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ∼ 14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts/kilogram). The RHHES space cell provides compatibility with automatic surface mounting technology. The cells can be easily combined to provide desired power levels and voltages. The RHHES space cell is more resistant to mechanical damage due to micrometeorites. Micro-meteorites which impinge upon conventional cells can crack the cell which, in turn, may cause string failure. The RHHES, operating in the same environment, can continue to function with a similar crack. The RHHES cell allows for very efficient thermal management which is essential for space cells generating higher specific power levels. The cell eliminates the need for electrical insulation layers which would otherwise increase the thermal resistance for conventional space panels. The RHHES cell can be applied to a space concentrator panel system without abandoning any of the attributes discussed. The power handling capability of the RHHES cell is approximately five times more than conventional space concentrator solar cells

  16. Decomposition of silicon carbide at high pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Daviau, Kierstin; Lee, Kanani K. M.

    2017-11-01

    We measure the onset of decomposition of silicon carbide, SiC, to silicon and carbon (e.g., diamond) at high pressures and high temperatures in a laser-heated diamond-anvil cell. We identify decomposition through x-ray diffraction and multiwavelength imaging radiometry coupled with electron microscopy analyses on quenched samples. We find that B3 SiC (also known as 3C or zinc blende SiC) decomposes at high pressures and high temperatures, following a phase boundary with a negative slope. The high-pressure decomposition temperatures measured are considerably lower than those at ambient, with our measurements indicating that SiC begins to decompose at ~ 2000 K at 60 GPa as compared to ~ 2800 K at ambient pressure. Once B3 SiC transitions to the high-pressure B1 (rocksalt) structure, we no longer observe decomposition, despite heating to temperatures in excess of ~ 3200 K. The temperature of decomposition and the nature of the decomposition phase boundary appear to be strongly influenced by the pressure-induced phase transitions to higher-density structures in SiC, silicon, and carbon. The decomposition of SiC at high pressure and temperature has implications for the stability of naturally forming moissanite on Earth and in carbon-rich exoplanets.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

  18. Synthetic Strategies for High Dielectric Constant Silicone Elastomers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt

    synthetic strategies were developed in this Ph.D. thesis, in order to create silicone elastomers with high dielectric constants and thereby higher energy densities. The work focused on maintaining important properties such as dielectric loss, electrical breakdown strength and elastic modulus....... The methodology therefore involved chemically grafting high dielectric constant chemical groups onto the elastomer network, as this would potentially provide a stable elastomer system upon continued activation of the material. The first synthetic strategy involved the synthesis of a new type of cross...... extender’ that allowed for chemical modifications such as Cu- AAC. This route was promising for one-pot elastomer preparation and as a high dielectric constant additive to commercial silicone systems. The second approach used the borane-catalysed Piers-Rubinsztajn reaction to form spatially well...

  19. Highly featured amorphous silicon nanorod arrays for high-performance lithium-ion batteries

    International Nuclear Information System (INIS)

    Soleimani-Amiri, Samaneh; Safiabadi Tali, Seied Ali; Azimi, Soheil; Sanaee, Zeinab; Mohajerzadeh, Shamsoddin

    2014-01-01

    High aspect-ratio vertical structures of amorphous silicon have been realized using hydrogen-assisted low-density plasma reactive ion etching. Amorphous silicon layers with the thicknesses ranging from 0.5 to 10 μm were deposited using radio frequency plasma enhanced chemical vapor deposition technique. Standard photolithography and nanosphere colloidal lithography were employed to realize ultra-small features of the amorphous silicon. The performance of the patterned amorphous silicon structures as a lithium-ion battery electrode was investigated using galvanostatic charge-discharge tests. The patterned structures showed a superior Li-ion battery performance compared to planar amorphous silicon. Such structures are suitable for high current Li-ion battery applications such as electric vehicles

  20. Highly featured amorphous silicon nanorod arrays for high-performance lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani-Amiri, Samaneh; Safiabadi Tali, Seied Ali; Azimi, Soheil; Sanaee, Zeinab; Mohajerzadeh, Shamsoddin, E-mail: mohajer@ut.ac.ir [Thin Film and Nanoelectronics Lab, Nanoelectronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran 143957131 (Iran, Islamic Republic of)

    2014-11-10

    High aspect-ratio vertical structures of amorphous silicon have been realized using hydrogen-assisted low-density plasma reactive ion etching. Amorphous silicon layers with the thicknesses ranging from 0.5 to 10 μm were deposited using radio frequency plasma enhanced chemical vapor deposition technique. Standard photolithography and nanosphere colloidal lithography were employed to realize ultra-small features of the amorphous silicon. The performance of the patterned amorphous silicon structures as a lithium-ion battery electrode was investigated using galvanostatic charge-discharge tests. The patterned structures showed a superior Li-ion battery performance compared to planar amorphous silicon. Such structures are suitable for high current Li-ion battery applications such as electric vehicles.

  1. High breakdown-strength composites from liquid silicone rubbers

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Zakaria, Shamsul Bin; Yu, Liyun

    2014-01-01

    In this paper we investigate the performance of liquid silicone rubbers (LSRs) as dielectric elastomer transducers. Commonly used silicones in this application include room-temperature vulcanisable (RTV) silicone elastomers and composites thereof. Pure LSRs and their composites with commercially...

  2. Dissection of QTLs for Hull Silicon Content on the Short Arm of Rice Chromosome 6

    Directory of Open Access Journals (Sweden)

    Ji-rong WU

    2010-06-01

    Full Text Available The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2:3 population segregating in the RM587–RM19784 region harboring qHUS6 in an isogenic background, two QTLs for hull silicon content were detected, of which qHUS6-1 was located in the distal region and qHUS6-2 in the region proximal to the centromere. Three rice plants carrying small heterozygous segments in the target region were selected, of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region. Three F2:3 populations were derived from the selfed seeds of the three plants, respectively. QTL mapping was performed using the two populations segregating in the qHUS6-1 region, and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417. Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2:3 population. Two QTLs were separated with two-way ANOVA, of which qHUS6-2a was located in the interval defined by RM19706–RM19795 and qHUS6-2b in the interval RM314–RM19665.

  3. High Performance Electronics on Flexible Silicon

    KAUST Repository

    Sevilla, Galo T.

    2016-09-01

    Over the last few years, flexible electronic systems have gained increased attention from researchers around the world because of their potential to create new applications such as flexible displays, flexible energy harvesters, artificial skin, and health monitoring systems that cannot be integrated with conventional wafer based complementary metal oxide semiconductor processes. Most of the current efforts to create flexible high performance devices are based on the use of organic semiconductors. However, inherent material\\'s limitations make them unsuitable for big data processing and high speed communications. The objective of my doctoral dissertation is to develop integration processes that allow the transformation of rigid high performance electronics into flexible ones while maintaining their performance and cost. In this work, two different techniques to transform inorganic complementary metal-oxide-semiconductor electronics into flexible ones have been developed using industry compatible processes. Furthermore, these techniques were used to realize flexible discrete devices and circuits which include metal-oxide-semiconductor field-effect-transistors, the first demonstration of flexible Fin-field-effect-transistors, and metal-oxide-semiconductors-based circuits. Finally, this thesis presents a new technique to package, integrate, and interconnect flexible high performance electronics using low cost additive manufacturing techniques such as 3D printing and inkjet printing. This thesis contains in depth studies on electrical, mechanical, and thermal properties of the fabricated devices.

  4. A high-temperature silicon-on-insulator stress sensor

    International Nuclear Information System (INIS)

    Wang Zheyao; Tian Kuo; Zhou Youzheng; Pan Liyang; Liu Litian; Hu Chaohong

    2008-01-01

    A piezoresistive stress sensor is developed using silicon-on-insulator (SOI) wafers and calibrated for stress measurement for high-temperature applications. The stress sensor consists of 'silicon-island-like' piezoresistor rosettes that are etched on the SOI layer. This eliminates leakage current and enables excellent electrical insulation at high temperature. To compensate for the measurement errors caused by the misalignment of the piezoresistor rosettes with respect to the crystallographic axes, an anisotropic micromachining technique, tetramethylammonium hydroxide etching, is employed to alleviate the misalignment issue. To realize temperature-compensated stress measurement, a planar diode is fabricated as a temperature sensor to decouple the temperature information from the piezoresistors, which are sensitive to both stress and temperature. Design, fabrication and calibration of the piezoresistors are given. SOI-related characteristics such as piezoresistive coefficients and temperature coefficients as well as the influence of the buried oxide layer are discussed in detail

  5. Heavy doping effects in high efficiency silicon solar cells

    Science.gov (United States)

    Lindholm, F. A.; Neugroschel, A.

    1986-01-01

    The temperature dependence of the emitter saturation current for bipolar devices was studied by varying the surface recombination velocity at the emitter surface. From this dependence, the value was derived for bandgap narrowing that is in better agreement with other determinations that were obtained from the temperature dependence measure on devices with ohmic contacts. Results of the first direct measurement of the minority-carrier transit time in a transparent heavily doped emitter layer were reported. The value was obtained by a high-frequency conductance method recently developed and used for doped Si. Experimental evidence is presented for significantly greater charge storage in highly excited silicon near room temperature than conventional theory would predict. These data are compared with various data for delta E sub G in heavily doped silicon.

  6. Silicone rubber curing by high intensity infrared radiation

    International Nuclear Information System (INIS)

    Huang, T.; Tsai, J.; Cherng, C.; Chen, J.

    1994-01-01

    A high-intensity (12 kW) and compact (80 cm) infrared heating oven for fast curing (12 seconds) of tube-like silicone rubber curing studies is reported. Quality inspection by DSC and DMA and results from pilot-scale curing oven all suggest that infrared heating provides a better way of vulcanization regarding to curing time, quality, cost, and spacing over conventional hot air heating. copyright 1995 American Institute of Physics

  7. High-efficiency concentrator silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  8. Infrared-transmission spectra and hydrogen content of hydrogenated amorphous silicon

    Science.gov (United States)

    Hu, Yuehi; Chen, Guanghua; Wu, Yueying; Yin, Shengyi; Gao, Zhuo; Wang, Qing; Song, Xuemei; Deng, Jinxiang

    2004-05-01

    In this paper, two kinds of methods of calculating the hydrogen content of a-Si:H thin film by means of the wagging mode and the stretching modes of infrared-transmission spectra, are investigated. The reason for the difference in these two calculation results is analyzed. If the contents of SiH2 and (SiH2) n are indicated in terms of a structure factor F=(/840+/880)//2000, it is shown that the calculation results obtained from the two different methods are almost equal when the refractive index n is approximately 3.4 or the fitting thickness is between 0.71 and 0.89 μm in the case of a small F. It is shown that the ways of fabrication of thin film can influences silicon-hydrogen bonding configuration of a-Si: H film, and different ways of fabrication can lead to different contents of SiH2 and (SiH2) n . The uniformity of the thin film with a big F is bad. In this case, there is great difference between the thickness measured by the SurfCom408A surface profile apparatus and the thickness obtained by fitting the fringes; and the hydrogen contents of a-Si:H films obtained by means of the wagging mode and the stretching modes are different, too. But the fabrication of the MWECR CVD assisted by CAT CVD can effectively restrain the formation of SiH2 and (SiH2) n .

  9. Mesoporous Silicon-Based Anodes for High Capacity, High Performance Li-ion Batteries, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, the active anode...

  10. High aspect ratio channels in glass and porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Liang, H.D. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Nanoscience and Nanotechnology Initiative (NNI), National University of Singapore, Singapore 117411 (Singapore); Dang, Z.Y. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Wu, J.F. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Kan, J.A. van; Qureshi, S. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Ynsa, M.D.; Torres-Costa, V. [Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Centro de Micro-Análisis de Materiales (CMAM), Universidad Autónoma de Madrid, Campus de Cantoblanco Edif. 22, Faraday 3, E-28049 Madrid (Spain); Maira, A. [Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Venkatesan, T.V. [Nanoscience and Nanotechnology Initiative (NNI), National University of Singapore, Singapore 117411 (Singapore); Breese, M.B.H., E-mail: phymbhb@nus.edu.sg [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

    2017-03-01

    We have developed a micromachining process to produce high-aspect-ratio channels and holes in glass and porous silicon. Our process utilizes MeV proton beam irradiation of silicon using direct writing with a focused beam, followed by electrochemical etching. To increase throughput we have also developed another process for large area ion irradiation based on a radiation-resistant gold surface mask, allowing many square inches to be patterned. We present a study of the achievable channel width, depth and period and sidewall verticality for a range of channels which can be over 100 μm deep or 100 nm wide with aspect ratios up to 80. This process overcomes the difficulty of machining glass on a micro- and nanometer scale which has limited many areas of applications in different fields such as microelectronics and microfluidics.

  11. High frequency guided wave propagation in monocrystalline silicon wafers

    Science.gov (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

    2017-04-01

    Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full three-dimensional Finite Element simulations of the guided wave propagation were conducted to visualize and quantify these effects for a line source. The phase velocity (slowness) and skew angle of the two fundamental Lamb wave modes (first anti-symmetric mode A0 and first symmetric mode S0) for varying propagation directions relative to the crystal orientation were measured experimentally. Selective mode excitation was achieved using a contact piezoelectric transducer with a custom-made wedge and holder to achieve a controlled contact pressure. The out-of-plane component of the guided wave propagation was measured using a noncontact laser interferometer. Good agreement was found with the simulation results and theoretical predictions based on nominal material properties of the silicon wafer.

  12. A radioagent method for determination of traces of phosphorus in high-purity silicon

    International Nuclear Information System (INIS)

    Chen, P.Y.; Chen, J.S.; Sun, H.J.; Yang, M.H.

    1985-01-01

    The feasibility of the determination of phosphorus at the extreme trace levels in high-purity silicon by radioreagent method is explored. After silicon dissolution with hydrofluoric and nitric acids and matrix volatilization, 12-molybdophosphoric acid is formed by the addition of the reagent, sup(99)MoOsub(4)sup(2-), in nitric acid medium and then extracted into isobutyl acetate. By plotting the phosphorus content against the radioactivity of sup(99)Mo in the organic phase, a linear relationship persisting down to 5 ng is obtained. Special effort was made to eliminate the unreacted sup(99)MoOsub(4)sup(2-) reagent and the optimal control of phosphorus blank introduced through the multistage analytical procedure in order to ensure reliable determination of phosphorus at the ppb level. (author)

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano...... calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils...

  14. Diamond and silicon pixel detectors in high radiation environments

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Jieh-Wen

    2012-10-15

    Diamond pixel detector is a promising candidate for tracking of collider experiments because of the good radiation tolerance of diamond. The diamond pixel detector must withstand the radiation damage from 10{sup 16} particles per cm{sup 2}, which is the expected total fluence in High Luminosity Large Hadron Collider. The performance of diamond and silicon pixel detectors are evaluated in this research in terms of the signal-to-noise ratio (SNR). Single-crystal diamond pixel detectors with the most recent readout chip ATLAS FE-I4 are produced and characterized. Based on the results of the measurement, the SNR of diamond pixel detector is evaluated as a function of radiation fluence, and compared to that of planar-silicon ones. The deterioration of signal due to radiation damage is formulated using the mean free path of charge carriers in the sensor. The noise from the pixel readout circuit is simulated and calculated with leakage current and input capacitance to the amplifier as important parameters. The measured SNR shows good agreement with the calculated and simulated results, proving that the performance of diamond pixel detectors can exceed the silicon ones if the particle fluence is more than 10{sup 15} particles per cm{sup 2}.

  15. Brain inspired high performance electronics on flexible silicon

    KAUST Repository

    Sevilla, Galo T.

    2014-06-01

    Brain\\'s stunning speed, energy efficiency and massive parallelism makes it the role model for upcoming high performance computation systems. Although human brain components are a million times slower than state of the art silicon industry components [1], they can perform 1016 operations per second while consuming less power than an electrical light bulb. In order to perform the same amount of computation with today\\'s most advanced computers, the output of an entire power station would be needed. In that sense, to obtain brain like computation, ultra-fast devices with ultra-low power consumption will have to be integrated in extremely reduced areas, achievable only if brain folded structure is mimicked. Therefore, to allow brain-inspired computation, flexible and transparent platform will be needed to achieve foldable structures and their integration on asymmetric surfaces. In this work, we show a new method to fabricate 3D and planar FET architectures in flexible and semitransparent silicon fabric without comprising performance and maintaining cost/yield advantage offered by silicon-based electronics.

  16. Diamond and silicon pixel detectors in high radiation environments

    International Nuclear Information System (INIS)

    Tsung, Jieh-Wen

    2012-10-01

    Diamond pixel detector is a promising candidate for tracking of collider experiments because of the good radiation tolerance of diamond. The diamond pixel detector must withstand the radiation damage from 10 16 particles per cm 2 , which is the expected total fluence in High Luminosity Large Hadron Collider. The performance of diamond and silicon pixel detectors are evaluated in this research in terms of the signal-to-noise ratio (SNR). Single-crystal diamond pixel detectors with the most recent readout chip ATLAS FE-I4 are produced and characterized. Based on the results of the measurement, the SNR of diamond pixel detector is evaluated as a function of radiation fluence, and compared to that of planar-silicon ones. The deterioration of signal due to radiation damage is formulated using the mean free path of charge carriers in the sensor. The noise from the pixel readout circuit is simulated and calculated with leakage current and input capacitance to the amplifier as important parameters. The measured SNR shows good agreement with the calculated and simulated results, proving that the performance of diamond pixel detectors can exceed the silicon ones if the particle fluence is more than 10 15 particles per cm 2 .

  17. High Temperature Corrosion of Silicon Carbide and Silicon Nitride in Water Vapor

    Science.gov (United States)

    Opila, E. J.; Robinson, Raymond C.; Cuy, Michael D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Silicon carbide (SiC) and silicon nitride (Si3N4) are proposed for applications in high temperature combustion environments containing water vapor. Both SiC and Si3N4 react with water vapor to form a silica (SiO2) scale. It is therefore important to understand the durability of SiC, Si3N4 and SiO2 in water vapor. Thermogravimetric analyses, furnace exposures and burner rig results were obtained for these materials in water vapor at temperatures between 1100 and 1450 C and water vapor partial pressures ranging from 0.1 to 3.1 atm. First, the oxidation of SiC and Si3N4 in water vapor is considered. The parabolic kinetic rate law, rate dependence on water vapor partial pressure, and oxidation mechanism are discussed. Second, the volatilization of silica to form Si(OH)4(g) is examined. Mass spectrometric results, the linear kinetic rate law and a volatilization model based on diffusion through a gas boundary layer are discussed. Finally, the combined oxidation and volatilization reactions, which occur when SiC or Si3N4 are exposed in a water vapor-containing environment, are presented. Both experimental evidence and a model for the paralinear kinetic rate law are shown for these simultaneous oxidation and volatilization reactions.

  18. High-rate silicon nitride deposition for photovoltaics : from fundamentals to industrial application

    NARCIS (Netherlands)

    Kessels, W.M.M.; Oever, van den P.J.; Bosch, R.C.M.; Bijker, M.D.; Evers, M.F.J.; Schram, D.C.; Sanden, van de M.C.M.

    2005-01-01

    The development of a novel plasma technique for high rate (> 1 nm/s) silicon nitride deposition for multifunctional antireflection coatings on crystalline silicon solar cells is described. The research has involved the analysis of the structural and optical properties of the silicon nitride films as

  19. High-rate silicon nitride deposition for photovoltaics : from fundamentals to industrial application

    NARCIS (Netherlands)

    Kessels, W.M.M.; Oever, van den P.J.; Bosch, R.C.M.; Bijker, M.D.; Evers, M.F.J.; Schram, D.C.; Sanden, van de M.C.M.

    2004-01-01

    The development of a novel plasma technique for high rate (> 1 nm/s) silicon nitride deposition for multifunctional antireflection coatings on crystalline silicon solar cells is described. The research has involved the analysis of the structural and optical properties of the silicon nitride films as

  20. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  1. Dependence of RF power on the content and configuration of hydrogen in amorphous hydrogenated silicon by reactive sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Imura, T; Ushita, K; Mogi, K; Hiraki, A [Osaka Univ., Suita (Japan). Faculty of Engineering

    1981-06-01

    Infrared absorption spectra at stretching bands of Si-H were investigated in hydrogenated amorphous silicon fabricated by reactive sputtering in the atmosphere of Ar and H/sub 2/ (10 mole%) at various input rf powers in the range from 0.8 to 3.8 W/cm/sup 2/. Hydrogen content mainly due to the configuration of Si=H/sub 2/ in the film increased with the decreasing rf power, as the deposition rate was decreased. On the other hand, the quantity of the monohydride (Si-H) configuration depended less on the power. Attachment of hydrogen molecules onto the fresh and reactive surface of silicon deposited successively was proposed for possible process of hydrogen incusion into amorphous silicon resulting in Si=H/sub 2/ configuration. The photoconductivity increased as the input power became higher, when the deposition rate also increased linearly with the power.

  2. High performance high-κ/metal gate complementary metal oxide semiconductor circuit element on flexible silicon

    KAUST Repository

    Sevilla, Galo T.

    2016-02-29

    Thinned silicon based complementary metal oxide semiconductor(CMOS)electronics can be physically flexible. To overcome challenges of limited thinning and damaging of devices originated from back grinding process, we show sequential reactive ion etching of silicon with the assistance from soft polymeric materials to efficiently achieve thinned (40 μm) and flexible (1.5 cm bending radius) silicon based functional CMOSinverters with high-κ/metal gate transistors. Notable advances through this study shows large area of silicon thinning with pre-fabricated high performance elements with ultra-large-scale-integration density (using 90 nm node technology) and then dicing of such large and thinned (seemingly fragile) pieces into smaller pieces using excimer laser. The impact of various mechanical bending and bending cycles show undeterred high performance of flexible siliconCMOSinverters. Future work will include transfer of diced silicon chips to destination site, interconnects, and packaging to obtain fully flexible electronic systems in CMOS compatible way.

  3. Silicon sensors for trackers at high-luminosity environment

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, Timo, E-mail: timo.peltola@helsinki.fi

    2015-10-01

    The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system that was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than in the current LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 Collaboration “Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders” to develop silicon sensors with sufficient radiation tolerance. Research topics include the improvement of the intrinsic radiation tolerance of the sensor material and novel detector designs with benefits like reduced trapping probability (thinned and 3D sensors), maximized sensitive area (active edge sensors) and enhanced charge carrier generation (sensors with intrinsic gain). A review of the recent results from both measurements and TCAD simulations of several detector technologies and silicon materials at radiation levels expected for HL-LHC will be presented. - Highlights: • An overview of the recent results from the RD50 collaboration. • Accuracy of TCAD simulations increased by including both bulk and surface damage. • Sensors with n-electrode readout and MCz material offer higher radiation hardness. • 3D detectors are a promising choice for the extremely high fluence environments. • Detectors with an enhanced charge carrier generation under systematic investigation.

  4. High temperature corrosion of silicon carbide and silicon nitride in the presence of chloride compound

    International Nuclear Information System (INIS)

    McNallan, M.

    1993-01-01

    Silicon carbide and silicon nitride are resistant to oxidation because a protective silicon dioxide films on their surfaces in most oxidizing environments. Chloride compounds can attack the surface in two ways: 1) chlorine can attack the silicon directly to form a volatile silicon chloride compound or 2) alkali compounds combined with the chlorine can be transported to the surface where they flux the silica layer by forming stable alkali silicates. Alkali halides have enough vapor pressure that a sufficient quantity of alkali species to cause accelerated corrosion can be transported to the ceramic surface without the formation of a chloride deposit. When silicon carbide is attacked simultaneously by chlorine and oxygen, the corrosion products include both volatile and condensed spices. Silicon nitride is much more resistance to this type of attack than silicon carbide. Silicon based ceramics are exposed to oxidizing gases in the presence of alkali chloride vapors, the rate of corrosion is controlled primarily by the driving force for the formation of alkali silicate, which can be quantified as the activity of the alkali oxide in equilibrium with the corrosive gas mixture. In a gas mixture containing a fixed partial pressure of KCl, the rate of corrosion is accelerated by increasing the concentration of water vapor and inhibited by increasing the concentration of HCl. Similar results have been obtained for mixtures containing other alkalis and halogens. (Orig./A.B.)

  5. Investigation on the improved radiation hardness of silicon detectors with high oxygen concentration

    CERN Document Server

    Moll, Michael; Lindström, G

    2000-01-01

    We present an investigation on the influence of the oxygen concentration on radiation-induced changes in the effective doping concentration of silicon detectors. Diodes fabricated from silicon with interstitial oxygen content ranging from below 2*10/sup 14/ to 9*10/sup 17/ cm/sup -3/ have been irradiated with fast neutrons up to a fluence of 2*10/sup 15/ cm/sup -2/. Our main interest focused on the so-called stable damage component in the change of the effective doping concentration being of prime importance for the application of silicon detectors in high-energy physics experiments. We demonstrate, that with a high oxygen enrichment the donor removal is appreciably reduced, reaching a value of only 10601130f the initial doping concentration for [O/sub i/]=9*10/sup 17/ cm/sup -3/, while for normal detector grade material with [O/sub i/] below 5*10/sup 16/ cm /sup -3/ that value is 60-90Furthermore, we show that the fluence proportional introduction of stable acceptors is independent of the oxygen concentratio...

  6. High Content Screening: Understanding Cellular Pathway

    International Nuclear Information System (INIS)

    Mohamed Zaffar Ali Mohamed Amiroudine; Daryl Jesus Arapoc; Zainah Adam; Shafii Khamis

    2015-01-01

    High content screening (HCS) is the convergence between cell-based assays, high-resolution fluorescence imaging, phase-contrast imaging of fixed- or live-cell assays, tissues and small organisms. It has been widely adopted in the pharmaceutical and biotech industries for target identification and validation and as secondary screens to reveal potential toxicities or to elucidate a drugs mechanism of action. By using the ImageXpress® Micro XLS System HCS, the complex network of key players controlling proliferation and apoptosis can be reduced to several sentinel markers for analysis. Cell proliferation and apoptosis are two key areas in cell biology and drug discovery research. Understanding the signaling pathways in cell proliferation and apoptosis is important for new therapeutic discovery because the imbalance between these two events is predominant in the progression of many human diseases, including cancer. The DNA binding dye DAPI is used to determine the nuclear size and nuclear morphology as well as cell cycle phases by DNA content. Images together with MetaXpress® analysis results provide a convenient and easy to use solution to high volume image management. In particular, HCS platform is beginning to have an important impact on early drug discovery, basic research in systems cell biology, and is expected to play a role in personalized medicine or revealing off-target drug effects. (author)

  7. Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor

    Energy Technology Data Exchange (ETDEWEB)

    Hänninen, Tuomas, E-mail: tuoha@ifm.liu.se; Schmidt, Susann; Jensen, Jens; Hultman, Lars; Högberg, Hans [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden)

    2015-09-15

    Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content. The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse.

  8. Passivating electron contact based on highly crystalline nanostructured silicon oxide layers for silicon solar cells

    Czech Academy of Sciences Publication Activity Database

    Stuckelberger, J.; Nogay, G.; Wyss, P.; Jeangros, Q.; Allebe, Ch.; Debrot, F.; Niquille, X.; Ledinský, Martin; Fejfar, Antonín; Despeisse, M.; Haug, F.J.; Löper, P.; Ballif, C.

    2016-01-01

    Roč. 158, Dec (2016), s. 2-10 ISSN 0927-0248 R&D Projects: GA MŠk LM2015087 Institutional support: RVO:68378271 Keywords : surface passivation * passivating contact * nanostructure * silicon oxide * nanocrystalline * microcrystalline * poly-silicon * crystallization * Raman * transmission line measurement Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.784, year: 2016

  9. Development of Silicon Detectors for the High Luminosity LHC

    International Nuclear Information System (INIS)

    Eichhorn, Thomas Valentin

    2015-07-01

    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 16 n eq /cm 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 into the

  10. Silicon in Imperata cylindrica (L.) P. Beauv: content, distribution, and ultrastructure.

    Science.gov (United States)

    Rufo, Lourdes; Franco, Alejandro; de la Fuente, Vicenta

    2014-07-01

    Silicon concentration, distribution, and ultrastructure of silicon deposits in the Poaceae Imperata cylindrica (L.) P. Beauv. have been studied. This grass, known for its medicinal uses and also for Fe hyperaccumulation and biomineralization capacities, showed a concentration of silicon of 13,705 ± 9,607 mg/kg dry weight. Silicon was found as an important constituent of cell walls of the epidermis of the whole plant. Silica deposits were found in silica bodies, endodermis, and different cells with silicon-collapsed lumen as bulliforms, cortical, and sclerenchyma cells. Transmission electron microscope observations of these deposits revealed an amorphous material of an ultrastructure similar to that previously reported in silica bodies of other Poaceae.

  11. High performance hybrid silicon micropillar solar cell based on light trapping characteristics of Cu nanoparticles

    Directory of Open Access Journals (Sweden)

    Yulong Zhang

    2018-05-01

    Full Text Available High performance silicon combined structure (micropillar with Cu nanoparticles solar cell has been synthesized from N-type silicon substrates based on the micropillar array. The combined structure solar cell exhibited higher short circuit current rather than the silicon miropillar solar cell, which the parameters of micropillar array are the same. Due to the Cu nanoparticles were decorated on the surface of silicon micropillar array, the photovoltaic properties of cells have been improved. In addition, the optimal efficiency of 11.5% was measured for the combined structure solar cell, which is better than the silicon micropillar cell.

  12. Broadband infrared photoluminescence in silicon nanowires with high density stacking faults.

    Science.gov (United States)

    Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Liu, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

    2015-02-07

    Making silicon an efficient light-emitting material is an important goal of silicon photonics. Here we report the observation of broadband sub-bandgap photoluminescence in silicon nanowires with a high density of stacking faults. The photoluminescence becomes stronger and exhibits a blue shift under higher laser powers. The super-linear dependence on excitation intensity indicates a strong competition between radiative and defect-related non-radiative channels, and the spectral blue shift is ascribed to the band filling effect in the heterostructures of wurtzite silicon and cubic silicon created by stacking faults.

  13. High performance hybrid silicon micropillar solar cell based on light trapping characteristics of Cu nanoparticles

    Science.gov (United States)

    Zhang, Yulong; Fan, Zhiqiang; Zhang, Weijia; Ma, Qiang; Jiang, Zhaoyi; Ma, Denghao

    2018-05-01

    High performance silicon combined structure (micropillar with Cu nanoparticles) solar cell has been synthesized from N-type silicon substrates based on the micropillar array. The combined structure solar cell exhibited higher short circuit current rather than the silicon miropillar solar cell, which the parameters of micropillar array are the same. Due to the Cu nanoparticles were decorated on the surface of silicon micropillar array, the photovoltaic properties of cells have been improved. In addition, the optimal efficiency of 11.5% was measured for the combined structure solar cell, which is better than the silicon micropillar cell.

  14. High temperature monitoring of silicon carbide ceramics by confocal energy dispersive X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi, E-mail: stx@bnu.edu.cn

    2016-04-15

    Highlights: • X-ray scattering was used for monitoring oxidation situation of SiC ceramics. • A calibration curve was obtained. • The confocal X-ray scattering technology was based on polycapillary X-ray optics. • The variations of contents of components of SiC ceramics were obtained. - Abstract: In the present work, we presented an alternative method for monitoring of the oxidation situation of silicon carbide (SiC) ceramics at various high temperatures in air by measuring the Compton-to-Rayleigh intensity ratios (I{sub Co}/I{sub Ra}) and effective atomic numbers (Z{sub eff}) of SiC ceramics with the confocal energy dispersive X-ray fluorescence (EDXRF) spectrometer. A calibration curve of the relationship between I{sub Co}/I{sub Ra} and Z{sub eff} was established by using a set of 8 SiC calibration samples. The sensitivity of this approach is so high that it can be easily distinguished samples of Z{sub eff} differing from each other by only 0.01. The linear relationship between the variation of Z{sub eff} and the variations of contents of C, Si and O of SiC ceramics were found, and the corresponding calculation model of the relationship between the ΔZ and the ΔC{sub C}, ΔC{sub Si}, and ΔC{sub O} were established. The variation of contents of components of the tested SiC ceramics after oxidation at high temperature was quantitatively calculated based on the model. It was shown that the results of contents of carbon, silicon and oxygen obtained by this method were in good agreement with the results obtained by XPS, giving values of relative deviation less than 1%. It was concluded that the practicality of this proposed method for monitoring of the oxidation situation of SiC ceramics at high temperatures was acceptable.

  15. The development of high resolution silicon x-ray microcalorimeters

    Science.gov (United States)

    Porter, F. S.; Kelley, R. L.; Kilbourne, C. A.

    2005-12-01

    Recently we have produced x-ray microcalorimeters with resolving powers approaching 2000 at 5.9 keV using a spare XRS microcalorimeter array. We attached 400 um square, 8 um thick HgTe absorbers using a variety of attachment methods to an XRS array and ran the detector array at temperatures between 40 and 60 mK. The best results were for absorbers attached using the standard XRS absorber-pixel thermal isolation scheme utilizing SU8 polymer tubes. In this scenario we achieved a resolution of 3.2 eV FWHM at 5.9 keV. Substituting a silicon spacer for the SU8 tubes also yielded sub-4eV results. In contrast, absorbers attached directly to the thermistor produced significant position dependence and thus degraded resolution. Finally, we tested standard 640um-square XRS detectors at reduced bias power at 50mK and achieved a resolution of 3.7eV, a 50% improvement over the XRS flight instrument. Implanted silicon microcalorimeters are a mature flight-qualified technology that still has a substantial phase space for future development. We will discuss these new high resolution results, the various absorber attachment schemes, planned future improvements, and, finally, their relevance to future high resolution x-ray spectrometers including Constellation-X.

  16. Silicon nanowire based high brightness, pulsed relativistic electron source

    Directory of Open Access Journals (Sweden)

    Deep Sarkar

    2017-06-01

    Full Text Available We demonstrate that silicon nanowire arrays efficiently emit relativistic electron pulses under irradiation by a high-intensity, femtosecond, and near-infrared laser (∼1018 W/cm2, 25 fs, 800 nm. The nanowire array yields fluxes and charge per bunch that are 40 times higher than those emitted by an optically flat surface, in the energy range of 0.2–0.5 MeV. The flux and charge yields for the nanowires are observed to be directional in nature unlike that for planar silicon. Particle-in-cell simulations establish that such large emission is caused by the enhancement of the local electric fields around a nanowire, which consequently leads to an enhanced absorption of laser energy. We show that the high-intensity contrast (ratio of picosecond pedestal to femtosecond peak of the laser pulse (10−9 is crucial to this large yield. We extend the notion of surface local-field enhancement, normally invoked in low-order nonlinear optical processes like second harmonic generation, optical limiting, etc., to ultrahigh laser intensities. These electron pulses, expectedly femtosecond in duration, have potential application in imaging, material modification, ultrafast dynamics, terahertz generation, and fast ion sources.

  17. High mechanical Q-factor measurements on silicon bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Nawrodt, R; Zimmer, A; Koettig, T; Schwarz, C; Heinert, D; Hudl, M; Neubert, R; Thuerk, M; Nietzsche, S; Vodel, W; Seidel, P [Friedrich-Schiller-Universitaet, Institut fuer Festkoerperphysik, Helmholtzweg 5, D-07743 Jena (Germany); Tuennermann, A [Friedrich-Schiller-Universitaet, Institut fuer Angewandte Physik, Max-Wien-Platz 1, D-07743 Jena (Germany)], E-mail: ronny.nawrodt@uni-jena.de

    2008-07-15

    Future gravitational wave detectors will be limited by different kinds of noise. Thermal noise from the coatings and the substrate material will be a serious noise contribution within the detection band of these detectors. Cooling and the use of a high mechanical Q-factor material as a substrate material will reduce the thermal noise contribution from the substrates. Silicon is one of the most interesting materials for a third generation cryogenic detector. Due to the fact that the coefficient of thermal expansion vanishes at 18 and 125 K the thermoelastic contribution to the thermal noise will disappear. We present a systematic analysis of the mechanical Q-factor at low temperatures between 5 and 300 K on bulk silicon (100) samples which are boron doped. The thickness of the cylindrical samples is varied between 6, 12, 24, and 75mm with a constant diameter of 3 inches. For the 75mm substrate a comparison between the (100) and the (111) orientation is presented. In order to obtain the mechanical Q-factor a ring-down measurement is performed. Thus, the substrate is excited to resonant vibrations by means of an electrostatic driving plate and the subsequent ring-down is recorded using a Michelson-like interferometer. The substrate itself is suspended as a pendulum by means of a tungsten wire loop. All measurements are carried out in a special cryostat which provides a temperature stability of better than 0.1K between 5 and 300K during the experiment. The influence of the suspension on the measurements is experimentally investigated and discussed. At 5.8K a highest Q-factor of 4.5 x 10{sup 8} was achieved for the 14.9 kHz mode of a silicon (100) substrate with a diameter of 3 inches and a thickness of 12 mm.

  18. 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.

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

    KAUST Repository

    Hussain, Muhammad Mustafa; Rojas, Jhonathan Prieto; Sevilla, Galo T.

    2013-01-01

    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.

  20. Production of low-silicon molten iron from high-silica hematite using biochar

    Institute of Scientific and Technical Information of China (English)

    Hui-qing Tang∗; Xiu-feng Fu; Yan-qi Qin; Shi-yu Zhao; Qing-guo Xue

    2017-01-01

    A new method of utilizing high-silica hematite to produce low-silicon molten iron was proposed.In this method, FASTMELT, which comprised direct reduction and melt separation processes, was applied, with highly reactive biochar as the reductant in the direct reduction stage.The proposed method was ex-perimentally investigated and the results show that the method is feasible.In the direct reduction stage, ore-char briquette could achieve a metallization rate of 84%-88% and residual carbon of 0.27-0.89 mass% at temperature of 1 373 K, biochar mixing ratio of 0.8-0.9, and reduction time of 15 min.Some silica particles remained embedded in the iron phase after the reduction.In the melting separation stage, molten iron with a carbon content of 0.02-0.03 mass% and silicon content of 0.02-0.18 mass% could be obtained from the metallic briquettes under the above-mentioned conditions; the iron recovery rate was 83%-91% and impurities in the obtained metal were negligible.

  1. Characterization of three high efficiency and blue sensitive silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Otte, Adam Nepomuk, E-mail: otte@gatech.edu; Garcia, Distefano; Nguyen, Thanh; Purushotham, Dhruv

    2017-02-21

    We report about the optical and electrical characterization of three high efficiency and blue sensitive Silicon photomultipliers from FBK, Hamamatsu, and SensL. Key features of the tested devices when operated at 90% breakdown probability are peak photon detection efficiencies between 40% and 55%, temperature dependencies of gain and PDE that are less than 1%/°C, dark rates of ∼50 kHz/mm{sup 2} at room temperature, afterpulsing of about 2%, and direct optical crosstalk between 6% and 20%. The characteristics of all three devices impressively demonstrate how the Silicon-photomultiplier technology has improved over the past ten years. It is further demonstrated how the voltage and temperature characteristics of a number of quantities can be parameterized on the basis of physical models. The models provide a deeper understanding of the device characteristics over a wide bias and temperature range. They also serve as examples how producers could provide the characteristics of their SiPMs to users. A standardized parameterization of SiPMs would enable users to find the optimal SiPM for their application and the operating point of SiPMs without having to perform measurements thus significantly reducing design and development cycles.

  2. Effect of small additions of silicon, iron, and aluminum on the room-temperature tensile properties of high-purity uranium

    International Nuclear Information System (INIS)

    Ludwig, R.L.

    1983-01-01

    Eleven binary and ternary alloys of uranium and very low concentrations of iron, silicon, and aluminum were prepared and tested for room-temperature tensile properties after various heat treatments. A yield strength approximately double that of high-purity derby uranium was obtained from a U-400 ppM Si-200 ppM Fe alloy after beta solution treatment and alpha aging. Higher silicon plus iron alloy contents resulted in increased yield strength, but showed an unacceptable loss of ductility

  3. Dependences of deposition rate and OH content on concentration of added trichloroethylene in low-temperature silicon oxide films deposited using silicone oil and ozone gas

    Science.gov (United States)

    Horita, Susumu; Jain, Puneet

    2018-03-01

    We investigated the dependences of the deposition rate and residual OH content of SiO2 films on the concentration of trichloroethylene (TCE), which was added during deposition at low temperatures of 160-260 °C with the reactant gases of silicone oil (SO) and O3. The deposition rate depends on the TCE concentration and is minimum at a concentration of ˜0.4 mol/m3 at 200 °C. The result can be explained by surface and gas-phase reactions. Experimentally, we also revealed that the thickness profile is strongly affected by gas-phase reaction, in which the TCE vapor was blown directly onto the substrate surface, where it mixed with SO and O3. Furthermore, it was found that adding TCE vapor reduces residual OH content in the SiO2 film deposited at 200 °C because TCE enhances the dehydration reaction.

  4. Development of high-efficiency solar cells on silicon web

    Science.gov (United States)

    Meier, D. L.; Greggi, J.; Okeeffe, T. W.; Rai-Choudhury, P.

    1986-01-01

    Work was performed to improve web base material with a goal of obtaining solar cell efficiencies in excess of 18% (AM1). Efforts in this program are directed toward identifying carrier loss mechanisms in web silicon, eliminating or reducing these mechanisms, designing a high efficiency cell structure with the aid of numerical models, and fabricating high efficiency web solar cells. Fabrication techniques must preserve or enhance carrier lifetime in the bulk of the cell and minimize recombination of carriers at the external surfaces. Three completed cells were viewed by cross-sectional transmission electron microscopy (TEM) in order to investigate further the relation between structural defects and electrical performance of web cells. Consistent with past TEM examinations, the cell with the highest efficiency (15.0%) had no dislocations but did have 11 twin planes.

  5. Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on dipolar copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede

    2014-01-01

    Dielectric elastomers (DES) are a promising new transducer technology, but high driving voltages limit their current commercial potential. One method used to lower driving voltage is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric...

  6. High content screening in microfluidic devices

    Science.gov (United States)

    Cheong, Raymond; Paliwal, Saurabh; Levchenko, Andre

    2011-01-01

    Importance of the field Miniaturization is key to advancing the state-of-the-art in high content screening (HCS), in order to enable dramatic cost savings through reduced usage of expensive biochemical reagents and to enable large-scale screening on primary cells. Microfluidic technology offers the potential to enable HCS to be performed with an unprecedented degree of miniaturization. Areas covered in this review This perspective highlights a real-world example from the authors’ work of HCS assays implemented in a highly miniaturized microfluidic format. Advantages of this technology are discussed, including cost savings, high throughput screening on primary cells, improved accuracy, the ability to study complex time-varying stimuli, and ease of automation, integration, and scaling. What the reader will gain The reader will understand the capabilities of a new microfluidics-based platform for HCS, and the advantages it provides over conventional plate-based HCS. Take home message Microfluidics technology will drive significant advancements and broader usage and applicability of HCS in drug discovery. PMID:21852997

  7. Thermoelectric Properties of High-Doped Silicon from Room Temperature to 900 K

    Science.gov (United States)

    Stranz, A.; Kähler, J.; Waag, A.; Peiner, E.

    2013-07-01

    Silicon is investigated as a low-cost, Earth-abundant thermoelectric material for high-temperature applications up to 900 K. For the calculation of module design the Seebeck coefficient and the electrical as well as thermal properties of silicon in the high-temperature range are of great importance. In this study, we evaluate the thermoelectric properties of low-, medium-, and high-doped silicon from room temperature to 900 K. In so doing, the Seebeck coefficient, the electrical and thermal conductivities, as well as the resulting figure of merit ZT of silicon are determined.

  8. Effect of Silicon application on Morpho-physiological Characteristics, Grain Yield and Nutrient Content of Bread Wheat under Water Stress Conditions

    Directory of Open Access Journals (Sweden)

    A. Karmollachaab

    2015-03-01

    Full Text Available In order to investigate the effect of silicon application on some physiological characteristics, yield and yield components, and grain mineral contents of bread wheat (Triticum aestivum under water stress condition, an experiment was conducted in Ramin Agriculture and Natural Resources University, Khuzestan, in 2012. The experiment was arranged in split-plots design in RCBD (Completely Randomized Blocks Design with three replications. Treatments consisted of drought stress (irrigation after 25, 50 and 75% depletion of Available Water Content in main plots and silicon (0, 10, 20 and 30 Kg Si ha-1 arranged in sub-plots. Results showed that the effect of drought stress was significant on most traits and led to the increase of electrolyte leakage (EL, cuticular wax, leaf and grain silicon content and grain nitrogen content. But drought led to negative impacts on grain yield and its components, and leaf potassium content, i.e. moderate and severe stresses reduced yield by 17% and 38% compared to control, respectively. Effect of silicon application was significant on all traits except for spike per square meter. Silicon had the greatest impact on EL and led to 35% decrease in this trait. Also, silicon led to increase in leaf and grain silicon contents and grain K content and grain yield and yield components, when applied at 30 kg ha-1. Generally, application of 30 kg ha-1 of silicon led to 6 and 14% increases of grain yield at the presence of moderate and severe drought stresses, respectively. Thus, given the abundance of silicon it can be used as an ameliorating element for planting bread wheat in drought-prone conditions.

  9. Crystalline-Amorphous Core−Shell Silicon Nanowires for High Capacity and High Current Battery Electrodes

    KAUST Repository

    Cui, Li-Feng

    2009-01-14

    Silicon is an attractive alloy-type anode material for lithium ion batteries because of its highest known capacity (4200 mAh/g). However silicon\\'s large volume change upon lithium insertion and extraction, which causes pulverization and capacity fading, has limited its applications. Designing nanoscale hierarchical structures is a novel approach to address the issues associated with the large volume changes. In this letter, we introduce a core-shell design of silicon nanowires for highpower and long-life lithium battery electrodes. Silicon crystalline- amorphous core-shell nanowires were grown directly on stainless steel current collectors by a simple one-step synthesis. Amorphous Si shells instead of crystalline Si cores can be selected to be electrochemically active due to the difference of their lithiation potentials. Therefore, crystalline Si cores function as a stable mechanical support and an efficient electrical conducting pathway while amorphous shells store Li ions. We demonstrate here that these core-shell nanowires have high charge storage capacity (̃1000 mAh/g, 3 times of carbon) with ̃90% capacity retention over 100 cycles. They also show excellent electrochemical performance at high rate charging and discharging (6.8 A/g, ̃20 times of carbon at 1 h rate). © 2009 American Chemical Society.

  10. Determination of silicon and aluminum in silicon carbide nanocrystals by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Dravecz, Gabriella; Bencs, László; Beke, Dávid; Gali, Adam

    2016-01-15

    The determination of Al contaminant and the main component Si in silicon carbide (SiC) nanocrystals with the size-distribution of 1-8nm dispersed in an aqueous solution was developed using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS). The vaporization/atomization processes were investigated in a transversally heated graphite atomizer by evaporating solution samples of Al and Si preserved in various media (HCl, HNO3). For Si, the best results were obtained by applying a mixture of 5µg Pd plus 5µg Mg, whereas for Al, 10µg Mg (each as nitrate solution) was dispensed with the samples, but the results obtained without modifier were found to be better. This way a maximum pyrolysis temperature of 1200°C for Si and 1300°C for Al could be used, and the optimum (compromise) atomization temperature was 2400°C for both analytes. The Si and Al contents of different sized SiC nanocrystals, dispersed in aqueous solutions, were determined against aqueous (external) calibration standards. The correlation coefficients (R values) of the calibrations were found to be 0.9963 for Si and 0.9991 for Al. The upper limit of the linear calibration range was 2mg/l Si and 0.25mg/l Al. The limit of detection was 3µg/l for Si and 0.5µg/l for Al. The characteristic mass (m0) was calculated to be 389pg Si and 6.4pg Al. The Si and Al content in the solution samples were found to be in the range of 1.0-1.7mg/l and 0.1-0.25mg/l, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. STATUS OF HIGH FLUX ISOTOPE REACTOR IRRADIATION OF SILICON CARBIDE/SILICON CARBIDE JOINTS

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yutai [ORNL; Koyanagi, Takaaki [ORNL; Kiggans, Jim [ORNL; Cetiner, Nesrin [ORNL; McDuffee, Joel [ORNL

    2014-09-01

    Development of silicon carbide (SiC) joints that retain adequate structural and functional properties in the anticipated service conditions is a critical milestone toward establishment of advanced SiC composite technology for the accident-tolerant light water reactor (LWR) fuels and core structures. Neutron irradiation is among the most critical factors that define the harsh service condition of LWR fuel during the normal operation. The overarching goal of the present joining and irradiation studies is to establish technologies for joining SiC-based materials for use as the LWR fuel cladding. The purpose of this work is to fabricate SiC joint specimens, characterize those joints in an unirradiated condition, and prepare rabbit capsules for neutron irradiation study on the fabricated specimens in the High Flux Isotope Reactor (HFIR). Torsional shear test specimens of chemically vapor-deposited SiC were prepared by seven different joining methods either at Oak Ridge National Laboratory or by industrial partners. The joint test specimens were characterized for shear strength and microstructures in an unirradiated condition. Rabbit irradiation capsules were designed and fabricated for neutron irradiation of these joint specimens at an LWR-relevant temperature. These rabbit capsules, already started irradiation in HFIR, are scheduled to complete irradiation to an LWR-relevant dose level in early 2015.

  12. Porous silicon phantoms for high-resolution scintillation imaging

    Energy Technology Data Exchange (ETDEWEB)

    Di Francia, G. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Scafe, R. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy)]. E-mail: scafe@casaccia.enea.it; De Vincentis, G. [Department of Radiological Sciences, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); La Ferrara, V. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Iurlaro, G. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy); Nasti, I. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Montani, L. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy); Pellegrini, R. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); Betti, M. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); Martucciello, N. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Pani, R. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy)

    2006-12-20

    High resolution radionuclide imaging requires phantoms with precise geometries and known activities using either Anger cameras equipped with pinhole collimators or dedicated small animal devices. Porous silicon samples, having areas of different shape and size, can be made and loaded with a radioactive material, obtaining: (a) precise radio-emitting figures corresponding to the porous areas geometry (b) a radioactivity of each figure depending on the pore's specifications, and (c) the same emission energy to be used in true exams. To this aim a sample with porous circular areas has been made and loaded with a {sup 99m}TcO{sub 4} {sup -} solution. Imaging has been obtained using both general purpose and pinhole collimators. This first sample shows some defects that are analyzed and discussed.

  13. Thermally stimulated current method applied to highly irradiated silicon diodes

    CERN Document Server

    Pintilie, I; Pintilie, I; Moll, Michael; Fretwurst, E; Lindström, G

    2002-01-01

    We propose an improved method for the analysis of Thermally Stimulated Currents (TSC) measured on highly irradiated silicon diodes. The proposed TSC formula for the evaluation of a set of TSC spectra obtained with different reverse biases leads not only to the concentration of electron and hole traps visible in the spectra but also gives an estimation for the concentration of defects which not give rise to a peak in the 30-220 K TSC temperature range (very shallow or very deep levels). The method is applied to a diode irradiated with a neutron fluence of phi sub n =1.82x10 sup 1 sup 3 n/cm sup 2.

  14. High yield silicon carbide pre-ceramic polymers

    International Nuclear Information System (INIS)

    Baney, R.H.

    1982-01-01

    Polysilanes which are substituted with (CH 3 ) 3 SiO-groups are useful for the preparation in high yields of fine grained silicon carbide ceramic materials. They consist of 0 to 60 mole % (CH 3 ) 2 Si units and 100 to 40 mole % CH 3 Si units, all Si valences not satisfied by CH 3 groups or Si atoms being directed to groups (CH 3 ) 3 SiO-, which siloxane groups amount to 23 to 61 weight % of the polysilane. They are prepared by reaction of the corresponding chloro- or bromo-methyl polysilanes with at least the stoichiometric amounts of (CH 3 ) 3 SiOSi(CH 3 ) 3 and water in the presence of a strong acid. (author)

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

    DEFF Research Database (Denmark)

    Jensen, Asger Sellerup

    This Ph.D. thesis treats various aspects of silicon photonics. From the limitations of silicon as a linear and nonlinear waveguide medium to its synergy with other waveguide materials. Various methods for reducing sidewall roughness and line edge roughness of silicon waveguides are attempted...... was too high for any practical applications. It is speculated that the attempt at creating a material with low density of dangling bonds was unsuccessful. Nevertheless, linear losses of 2.4dB/cm at 1550nm wavelength in the silicon waveguides remained sufficiently low that high speed nonlinear optical...

  16. Activation analysis for measurements of silicon, phosphorus, alkali metals and other elements in high-purity metals

    International Nuclear Information System (INIS)

    Schmid, W.

    1988-01-01

    In the present thesis, methods of activation analysis were developed for the determination of the elements silicon, phosphorus, potassium, sodium, i.a. in the high-purity metals vanadium, niobium, tantalum, tungsten, molybdenum and iron. The determination of silicon is based on the activation of samples with reactor neutrons, on a subsequent radiochemical separation of the tracer radionuclide 31 Si resulting from the reaction 30 Si(n,γ), and on the measurement of β activity with the help of a liquid scintillation measuring desk. Since the tracer radionuclide 31 Si almost exclusively emits β rays which are not sufficiently nuclide-specific, silicon was selectively separated from the other sample elements by being distilled as silicon tetrafluoride. The processing of the residue following the separation of silicon permits a complementary gamma-spectroscopic determination of a whole lot of additional elements. Thus, the separation of the nuclide 182 Ta with the anion exchanger Dowex 1X8 from HF/H 2 SO 4 medium permits the determination of 22 elements in vanadium, niobium and tantalum. Phosphorus content is determined by activating the samples with rapid neutrons (cyclotrons) via the reaction 31 P(n,p) 31 Si. (orig./MM) [de

  17. Structural and optical properties of silicon-carbide nanowires produced by the high-temperature carbonization of silicon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikov, A. V., E-mail: pavlikov@physics.msu.ru [Moscow State University, Faculty of Physics (Russian Federation); Latukhina, N. V.; Chepurnov, V. I. [Samara National Researh University (Russian Federation); Timoshenko, V. Yu. [Moscow State University, Faculty of Physics (Russian Federation)

    2017-03-15

    Silicon-carbide (SiC) nanowire structures 40–50 nm in diameter are produced by the high-temperature carbonization of porous silicon and silicon nanowires. The SiC nanowires are studied by scanning electron microscopy, X-ray diffraction analysis, Raman spectroscopy, and infrared reflectance spectroscopy. The X-ray structural and Raman data suggest that the cubic 3C-SiC polytype is dominant in the samples under study. The shape of the infrared reflectance spectrum in the region of the reststrahlen band 800–900 cm{sup –1} is indicative of the presence of free charge carriers. The possibility of using SiC nanowires in microelectronic, photonic, and gas-sensing devices is discussed.

  18. Research and development of photovoltaic power system. Development of novel technologies for fabrication of high quality silicon thin films for solar cells; Taiyoko hatsuden system no kenkyu kaihatsu. Kohinshitsu silicon usumaku sakusei gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, T [Kanazawa University, Ishikawa (Japan). Faculty of Engineering

    1994-12-01

    Described herein are the results of the FY1994 research program for development of novel technologies for fabrication of high quality thin films of silicon for solar cells. The study on the mechanisms and effects of chemical annealing reveals that the film structure greatly varies depending on substrate temperature during the hydrotreatment process, based on the tests with substrate temperature, deposition of superthin film (T1) and hydrotreatment (T2) as the variable parameters. Chemical annealing at low temperature produces a high-quality a-Si:H film of low defect content. The study on fabrication of thin polycrystalline silicon films at low temperature observes on real time the process of deposition of the thin films on polycrystalline silicon substrates, where a natural oxide film is removed beforehand from the substrate. The results indicate that a thin polycrystalline silicon film of 100% crystallinity can be formed even on a polycrystalline silicon substrate by controlling starting gas composition and substrate temperature. The layer-by-layer method is used as the means for forming the seed crystals on a glass substrate, where deposition and hydrotreatment are repeated alternately, to produce the thin crystalline silicon films of high crystallinity. 3 figs.

  19. Clustering in ICT: From Route 128 to Silicon Valley, from DEC to Google, from Hardware to Content

    NARCIS (Netherlands)

    W. Hulsink (Wim); D. Manuel; H. Bouwman (Harry)

    2007-01-01

    textabstractOne of the pioneers in academic entrepreneurship and high-tech clustering is MIT and the Route 128/Boston region. Silicon Valley centered around Stanford University was originally a fast follower and only later emerged as a scientific and industrial hotspot. Several technology and

  20. Bainite transformation of low carbon Mn-Si TRIP-assisted multiphase steels: influence of silicon content on cementite precipitation and austenite retention

    International Nuclear Information System (INIS)

    Jacques, P.; Catlin, T.; Geerlofs, N.; Kop, T.; Zwaag, S. van der; Delannay, F.

    1999-01-01

    Studies dealing with TRIP-assisted multiphase steels have emphasized the crucial role of the bainite transformation of silicon-rich intercritical austenite in the achievement of a good combination of strength and ductility. The present work deals with the bainite transformation in two steels differing in their silicon content. It is shown that both carbon enrichment of residual austenite and cementite precipitation influences the kinetics of the bainite transformation. A minimum silicon content is found to be necessary in order to prevent cementite precipitation from austenite during the formation of bainitic ferrite in such a way as to allow stabilisation of austenite by carbon enrichment. (orig.)

  1. A 1024 pad silicon detector to solve tracking ambiguities in high multiplicity events

    International Nuclear Information System (INIS)

    Simone, S.; Catanesi, M.G.; Di Bari, D.; Didonna, V.; Elia, D.; Ghidini, B.; Lenti, V.; Manzari, V.; Nappi, E.

    1996-01-01

    Silicon detectors with two-dimensional pad readout have been designed and constructed for the WA97 experiment at CERN, in order to solve ambiguities for track reconstruction in a silicon microstrip telescope. A high density fanouts has been developed on a glass support to allow the electrical contacts between the detector and the front end electronics. Silicon pad detectors have been successfully operated both during the proton-Pb and Pb-Pb runs of the WA97 experiment. (orig.)

  2. High performance high-κ/metal gate complementary metal oxide semiconductor circuit element on flexible silicon

    KAUST Repository

    Sevilla, Galo T.; Almuslem, A. S.; Gumus, Abdurrahman; Hussain, Aftab M.; Hussain, Aftab M.; Cruz, Melvin; Hussain, Muhammad Mustafa

    2016-01-01

    shows large area of silicon thinning with pre-fabricated high performance elements with ultra-large-scale-integration density (using 90 nm node technology) and then dicing of such large and thinned (seemingly fragile) pieces into smaller pieces using

  3. High-performance lithium battery anodes using silicon nanowires.

    Science.gov (United States)

    Chan, Candace K; Peng, Hailin; Liu, Gao; McIlwrath, Kevin; Zhang, Xiao Feng; Huggins, Robert A; Cui, Yi

    2008-01-01

    There is great interest in developing rechargeable lithium batteries with higher energy capacity and longer cycle life for applications in portable electronic devices, electric vehicles and implantable medical devices. Silicon is an attractive anode material for lithium batteries because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g(-1); ref. 2). Although this is more than ten times higher than existing graphite anodes and much larger than various nitride and oxide materials, silicon anodes have limited applications because silicon's volume changes by 400% upon insertion and extraction of lithium which results in pulverization and capacity fading. Here, we show that silicon nanowire battery electrodes circumvent these issues as they can accommodate large strain without pulverization, provide good electronic contact and conduction, and display short lithium insertion distances. We achieved the theoretical charge capacity for silicon anodes and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling.

  4. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor.

    Science.gov (United States)

    Lee, Jieun; Jang, Jaeman; Choi, Bongsik; Yoon, Jinsu; Kim, Jee-Yeon; Choi, Yang-Kyu; Kim, Dong Myong; Kim, Dae Hwan; Choi, Sung-Jin

    2015-07-21

    This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response of field-effect-transistor (FET)-based biosensors. The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential advantage of high density and low noise performance. The biosensor shows a current response of 5.74 decades per pH for pH detection, which is 2.5 × 10(5) times larger than that of a single SiNW sensor. In addition, we demonstrate charged polymer detection using the biosensor, with a high current change of 4.5 × 10(5) with a 500 nM concentration of poly(allylamine hydrochloride). In addition, we demonstrate a wide dynamic range can be obtained by adjusting the liquid gate voltage. We expect that this biosensor will be advantageous and practical for biosensor applications which requires lower noise, high speed, and high density.

  5. The status of silicon ribbon growth technology for high-efficiency silicon solar cells

    Science.gov (United States)

    Ciszek, T. F.

    1985-01-01

    More than a dozen methods have been applied to the growth of silicon ribbons, beginning as early as 1963. The ribbon geometry has been particularly intriguing for photovoltaic applications, because it might provide large area, damage free, nearly continuous substrates without the material loss or cost of ingot wafering. In general, the efficiency of silicon ribbon solar cells has been lower than that of ingot cells. The status of some ribbon growth techniques that have achieved laboratory efficiencies greater than 13.5% are reviewed, i.e., edge-defined, film-fed growth (EFG), edge-supported pulling (ESP), ribbon against a drop (RAD), and dendritic web growth (web).

  6. Electrical characterization of high-pressure reactive sputtered ScOx films on silicon

    International Nuclear Information System (INIS)

    Castan, H.; Duenas, S.; Gomez, A.; Garcia, H.; Bailon, L.; Feijoo, P.C.; Toledano-Luque, M.; Prado, A. del; San Andres, E.; Lucia, M.L.

    2011-01-01

    Al/ScO x /SiN x /n-Si and Al/ScO x /SiO x /n-Si metal-insulator-semiconductor capacitors have been electrically characterized. Scandium oxide was grown by high-pressure sputtering on different substrates to study the dielectric/insulator interface quality. The substrates were silicon nitride and native silicon oxide. The use of a silicon nitride interfacial layer between the silicon substrate and the scandium oxide layer improves interface quality, as interfacial state density and defect density inside the insulator are decreased.

  7. Fluorescent porous silicon biological probes with high quantum efficiency and stability.

    Science.gov (United States)

    Tu, Chang-Ching; Chou, Ying-Nien; Hung, Hsiang-Chieh; Wu, Jingda; Jiang, Shaoyi; Lin, Lih Y

    2014-12-01

    We demonstrate porous silicon biological probes as a stable and non-toxic alternative to organic dyes or cadmium-containing quantum dots for imaging and sensing applications. The fluorescent silicon quantum dots which are embedded on the porous silicon surface are passivated with carboxyl-terminated ligands through stable Si-C covalent bonds. The porous silicon bio-probes have shown photoluminescence quantum yield around 50% under near-UV excitation, with high photochemical and thermal stability. The bio-probes can be efficiently conjugated with antibodies, which is confirmed by a standard enzyme-linked immunosorbent assay (ELISA) method.

  8. Silicon micromachining using a high-density plasma source

    International Nuclear Information System (INIS)

    McAuley, S.A.; Ashraf, H.; Atabo, L.; Chambers, A.; Hall, S.; Hopkins, J.; Nicholls, G.

    2001-01-01

    Dry etching of Si is critical in satisfying the demands of the micromachining industry. The micro-electro-mechanical systems (MEMS) community requires etches capable of high aspect ratios, vertical profiles, good feature size control and etch uniformity along with high throughput to satisfy production requirements. Surface technology systems' (STS's) high-density inductively coupled plasma (ICP) etch tool enables a wide range of applications to be realized whilst optimizing the above parameters. Components manufactured from Si using an STS ICP include accelerometers and gyroscopes for military, automotive and domestic applications. STS's advanced silicon etch (ASE TM ) has also allowed the first generation of MEMS-based optical switches and attenuators to reach the marketplace. In addition, a specialized application for fabricating the next generation photolithography exposure masks has been optimized for 200 mm diameter wafers, to depths of ∼750 μm. Where the profile is not critical, etch rates of greater than 8 μm min -1 have been realized to replace previous methods such as wet etching. This is also the case for printer applications. Specialized applications that require etching down to pyrex or oxide often result in the loss of feature size control at the interface; this is an industry wide problem. STS have developed a technique to address this. The rapid progression of the industry has led to development of the STS ICP etch tool, as well as the process. (author)

  9. Investigation on the improved radiation hardness of silicon detectors with high oxygen concentration

    International Nuclear Information System (INIS)

    Moll, M.; Fretwurst, E.; Lindstroem, G.

    2000-01-01

    We present an investigation on the influence of the oxygen concentration on radiation-induced changes in the effective doping concentration of silicon detectors. Diodes fabricated from silicon with interstitial oxygen content ranging from below 2x10 14 to 9x10 17 cm -3 have been irradiated with fast neutrons up to a fluence of 2x10 15 cm -2 . Our main interest focused on the so-called stable damage component in the change of the effective doping concentration being of prime importance for the application of silicon detectors in high-energy physics experiments. We demonstrate, that with a high oxygen enrichment the donor removal is appreciably reduced, reaching a value of only 10% of the initial doping concentration for [O i ]=9x10 17 cm -3 , while for normal detector grade material with [O i ] below 5x10 16 cm -3 that value is 60-90%. Furthermore, we show that the fluence proportional introduction of stable acceptors is independent of the oxygen concentration with an averaged introduction rate of (1.49±0.03)x10 -2 cm -1 . Only one material was found exhibiting a significantly smaller value of about 0.6x10 -2 cm -1 and thus indicating the possibility to suppress the radiation-induced acceptor creation by material modification. Finally, we show that the experimental findings disagree in several important aspects with predictions made by microscopic defect kinetics models, leaving the physical background of some of the measured data as an open question

  10. Fabrication of detectors and transistors on high-resistivity silicon

    International Nuclear Information System (INIS)

    Holland, S.

    1988-06-01

    A new process for the fabrication of silicon p-i-n diode radiation detectors is described. The utilization of backside gettering in the fabrication process results in the actual physical removal of detrimental impurities from critical device regions. This reduces the sensitivity of detector properties to processing variables while yielding low diode reverse-leakage currents. In addition, gettering permits the use of processing temperatures compatible with integrated-circuit fabrication. P-channel MOSFETs and silicon p-i-n diodes have been fabricated simultaneously on 10 kΩ/centerreverse arrowdot/cm silicon using conventional integrated-circuit processing techniques. 25 refs., 5 figs

  11. Twin photon pairs in a high-Q silicon microresonator

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Steven; Lu, Xiyuan [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Jiang, Wei C. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Lin, Qiang, E-mail: qiang.lin@rochester.edu [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States)

    2015-07-27

    We report the generation of high-purity twin photon pairs through cavity-enhanced non-degenerate four-wave mixing (FWM) in a high-Q silicon microdisk resonator. Twin photon pairs are created within the same cavity mode and are consequently expected to be identical in all degrees of freedom. The device is able to produce twin photons at telecommunication wavelengths with a pair generation rate as large as (3.96 ± 0.03) × 10{sup 5} pairs/s, within a narrow bandwidth of 0.72 GHz. A coincidence-to-accidental ratio of 660 ± 62 was measured, the highest value reported to date for twin photon pairs, at a pair generation rate of (2.47 ± 0.04) × 10{sup 4} pairs/s. Through careful engineering of the dispersion matching window, we have reduced the ratio of photons resulting from degenerate FWM to non-degenerate FWM to less than 0.15.

  12. Evaluation of a high resolution silicon PET insert module

    Energy Technology Data Exchange (ETDEWEB)

    Grkovski, Milan, E-mail: milan.grkovski@ijs.si [Jožef Stefan Institute, Ljubljana (Slovenia); Memorial Sloan Kettering Cancer Center, New York, NY (United States); Brzezinski, Karol [IFIC/CSIC, Valencia (Spain); Cindro, Vladimir [Jožef Stefan Institute, Ljubljana (Slovenia); Clinthorne, Neal H. [University of Michigan, Ann Arbor, MI (United States); Kagan, Harris [Ohio State University, Columbus, OH (United States); Lacasta, Carlos [IFIC/CSIC, Valencia (Spain); Mikuž, Marko [Jožef Stefan Institute, Ljubljana (Slovenia); Solaz, Carles [IFIC/CSIC, Valencia (Spain); Studen, Andrej [Jožef Stefan Institute, Ljubljana (Slovenia); Weilhammer, Peter [Ohio State University, Columbus, OH (United States); Žontar, Dejan [Jožef Stefan Institute, Ljubljana (Slovenia)

    2015-07-11

    Conventional PET systems can be augmented with additional detectors placed in close proximity of the region of interest. We developed a high resolution PET insert module to evaluate the added benefit of such a combination. The insert module consists of two back-to-back 1 mm thick silicon sensors, each segmented into 1040 1 mm{sup 2} pads arranged in a 40 by 26 array. A set of 16 VATAGP7.1 ASICs and a custom assembled data acquisition board were used to read out the signal from the insert module. Data were acquired in slice (2D) geometry with a Jaszczak phantom (rod diameters of 1.2–4.8 mm) filled with {sup 18}F-FDG and the images were reconstructed with ML-EM method. Both data with full and limited angular coverage from the insert module were considered and three types of coincidence events were combined. The ratio of high-resolution data that substantially improves quality of the reconstructed image for the region near the surface of the insert module was estimated to be about 4%. Results from our previous studies suggest that such ratio could be achieved at a moderate technological expense by using an equivalent of two insert modules (an effective sensor thickness of 4 mm)

  13. Fabrication of High-Frequency pMUT Arrays on Silicon Substrates

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Zawada, Tomasz; Hansen, Karsten

    2010-01-01

    A novel technique based on silicon micromachining for fabrication of linear arrays of high-frequency piezoelectric micromachined ultrasound transducers (pMUT) is presented. Piezoelectric elements are formed by deposition of lead zirconia titanate into etched features of a silicon substrate...

  14. Operation of a high-purity silicon diode alpha particle detector at 1.4 K

    International Nuclear Information System (INIS)

    Martoff, C.J.; Kaczanowicz, E.; Neuhauser, B.J.; Lopez, E.; Zhang, Y.; Ziemba, F.P.

    1991-01-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm 2 by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.)

  15. Carbon−Silicon Core−Shell Nanowires as High Capacity Electrode for Lithium Ion Batteries

    KAUST Repository

    Cui, Li-Feng; Yang, Yuan; Hsu, Ching-Mei; Cui, Yi

    2009-01-01

    We introduce a novel design of carbon-silicon core-shell nanowires for high power and long life lithium battery electrodes. Amorphous silicon was coated onto carbon nanofibers to form a core-shell structure and the resulted core-shell nanowires

  16. Silicon Valley: Planet Startup : Disruptive Innovation, Passionate Entrepreneurship & High-tech Startups

    NARCIS (Netherlands)

    dr. A. Maas; Dr. P. Ester

    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

  17. Study of high energy ion implantation of boron and oxygen in silicon

    International Nuclear Information System (INIS)

    Thevenin, P.

    1991-06-01

    Three aspects of high energy (0.5-3 MeV) light ions ( 11 B + and 16 O + ) implantation in silicon are examined: (1)Spatial repartition; (2) Target damage and (3) Synthesis by oxygen implantation of a buried silicon oxide layer

  18. Development of a process for high capacity arc heater production of silicon for solar arrays

    Science.gov (United States)

    Meyer, T. N.

    1980-01-01

    A high temperature silicon production process using existing electric arc heater technology is discussed. Silicon tetrachloride and a reductant, liquid sodium, were injected into an arc heated mixture of hydrogen and argon. Under these high temperature conditions, a very rapid reaction occurred, yielding silicon and gaseous sodium chloride. Techniques for high temperature separation and collection of the molten silicon were developed. The desired degree of separation was not achieved. The electrical, control and instrumentation, cooling water, gas, SiCl4, and sodium systems are discussed. The plasma reactor, silicon collection, effluent disposal, the gas burnoff stack, and decontamination and safety are also discussed. Procedure manuals, shakedown testing, data acquisition and analysis, product characterization, disassembly and decontamination, and component evaluation are reviewed.

  19. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  20. Silicon detectors

    International Nuclear Information System (INIS)

    Klanner, R.

    1984-08-01

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  1. High-aspect-ratio, silicon oxide-enclosed pillar structures in microfluidic liquid chromatography.

    Science.gov (United States)

    Taylor, Lisa C; Lavrik, Nickolay V; Sepaniak, Michael J

    2010-11-15

    The present paper discusses the ability to separate chemical species using high-aspect-ratio, silicon oxide-enclosed pillar arrays. These miniaturized chromatographic systems require smaller sample volumes, experience less flow resistance, and generate superior separation efficiency over traditional packed bed liquid chromatographic columns, improvements controlled by the increased order and decreased pore size of the systems. In our distinctive fabrication sequence, plasma-enhanced chemical vapor deposition (PECVD) of silicon oxide is used to alter the surface and structural properties of the pillars for facile surface modification while improving the pillar mechanical stability and increasing surface area. The separation behavior of model compounds within our pillar systems indicated an unexpected hydrophobic-like separation mechanism. The effects of organic modifier, ionic concentration, and pressure-driven flow rate were studied. A decrease in the organic content of the mobile phase increased peak resolution while detrimentally effecting peak shape. A resolution of 4.7 (RSD = 3.7%) was obtained for nearly perfect Gaussian shaped peaks, exhibiting plate heights as low as 1.1 and 1.8 μm for fluorescein and sulforhodamine B, respectively. Contact angle measurements and DART mass spectrometry analysis indicate that our employed elastomeric soft bonding technique modifies pillar properties, creating a fortuitous stationary phase. This discovery provides evidence supporting the ability to easily functionalize PECVD oxide surfaces by gas-phase reactions.

  2. High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

    2014-01-01

    Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

  3. Confined high-pressure chemical deposition of hydrogenated amorphous silicon.

    Science.gov (United States)

    Baril, Neil F; He, Rongrui; Day, Todd D; Sparks, Justin R; Keshavarzi, Banafsheh; Krishnamurthi, Mahesh; Borhan, Ali; Gopalan, Venkatraman; Peacock, Anna C; Healy, Noel; Sazio, Pier J A; Badding, John V

    2012-01-11

    Hydrogenated amorphous silicon (a-Si:H) is one of the most technologically important semiconductors. The challenge in producing it from SiH(4) precursor is to overcome a significant kinetic barrier to decomposition at a low enough temperature to allow for hydrogen incorporation into a deposited film. The use of high precursor concentrations is one possible means to increase reaction rates at low enough temperatures, but in conventional reactors such an approach produces large numbers of homogeneously nucleated particles in the gas phase, rather than the desired heterogeneous deposition on a surface. We report that deposition in confined micro-/nanoreactors overcomes this difficulty, allowing for the use of silane concentrations many orders of magnitude higher than conventionally employed while still realizing well-developed films. a-Si:H micro-/nanowires can be deposited in this way in extreme aspect ratio, small-diameter optical fiber capillary templates. The semiconductor materials deposited have ~0.5 atom% hydrogen with passivated dangling bonds and good electronic properties. They should be suitable for a wide range of photonic and electronic applications such as nonlinear optical fibers and solar cells. © 2011 American Chemical Society

  4. Silicon photomultipliers. Properties and applications in a highly granular calorimeter

    International Nuclear Information System (INIS)

    Feege, Nils

    2008-12-01

    Silicon Photomultipliers (SiPMs) are novel semiconductor-based photodetectors operated in Geiger mode. Their response is not linear, and both their gain and their photon detection efficiency depend on the applied bias voltage and on temperature. The CALICE collaboration investigates several technology options for highly granular calorimeters for the future ILC. The prototype of a scintillator-steel sampling calorimeter with analogue readout for hadrons constructed at DESY and successfully operated in testbeam experiments at DESY, CERN and FNAL by this collaboration is the first large scale application for 7608 SiPMs developed by MEPhI. This thesis deals with properties of the SiPMs used in the calorimeter prototype. The effective numer of pixels of the SiPMs, which influences their saturation behaviour, is extracted from in situ measurements and compared to results obtained for the bare SiPMs. In addition, the effects of temperature and voltage changes on the parameters necessary for the calibration of the SiPMs and the detector are determined. Methods which allow for correcting or compensating these effects are evaluated. An approach to improve the absolute calibration of the temperature sensors in the prototype is described and temperature profiles are studied. Finally, a procedure to adjust the light yield of the cells of the prototype is presented. The results of the application of this procedure during the commissioning of the detector at FNAL are discussed. (orig.)

  5. Silicon photomultipliers. Properties and applications in a highly granular calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Feege, Nils

    2008-12-15

    Silicon Photomultipliers (SiPMs) are novel semiconductor-based photodetectors operated in Geiger mode. Their response is not linear, and both their gain and their photon detection efficiency depend on the applied bias voltage and on temperature. The CALICE collaboration investigates several technology options for highly granular calorimeters for the future ILC. The prototype of a scintillator-steel sampling calorimeter with analogue readout for hadrons constructed at DESY and successfully operated in testbeam experiments at DESY, CERN and FNAL by this collaboration is the first large scale application for 7608 SiPMs developed by MEPhI. This thesis deals with properties of the SiPMs used in the calorimeter prototype. The effective numer of pixels of the SiPMs, which influences their saturation behaviour, is extracted from in situ measurements and compared to results obtained for the bare SiPMs. In addition, the effects of temperature and voltage changes on the parameters necessary for the calibration of the SiPMs and the detector are determined. Methods which allow for correcting or compensating these effects are evaluated. An approach to improve the absolute calibration of the temperature sensors in the prototype is described and temperature profiles are studied. Finally, a procedure to adjust the light yield of the cells of the prototype is presented. The results of the application of this procedure during the commissioning of the detector at FNAL are discussed. (orig.)

  6. Observations of silicon carbide by high resolution transmission electron microscopy

    International Nuclear Information System (INIS)

    Smith, D.J.; Jepps, N.W.; Page, T.F.

    1978-01-01

    High resolution transmission electron microscopy techniques, principally involving direct lattice imaging, have been used as part of a study of the crystallography and phase transformation mechanics of silicon carbide polytypes. In particular, the 3C (cubic) and 6H (hexagonal) polytypes have been examined together with partially transformed structural mixtures. Although direct observation of two-dimensional atomic structures was not possible at an operating voltage of 100 kV, considerable microstructural information has been obtained by careful choice of the experimental conditions. In particular, tilted beam observations of the 0.25 nm lattice fringes have been made in the 3C polytype for two different brace 111 brace plane arrays in order to study the dimensions and coherency of finely-twinned regions together with brace 0006 brace and brace 1 0 bar1 2 brace lattice images in the 6H polytype which allow the detailed stacking operations to be resolved. Lower resolution lattice images formed with axial illumination have also been used to study the nature of the 3C → 6H transformation and results are presented showing that the transformation interface may originate with fine twinning of the 3C structure followed by growth of the resultant 6H regions. Observations have been made of the detailed stepped structure of this interface together with the stacking fault distribution in the resultant 6H material. (author)

  7. TRANSFORMATIONS IN NANO-DIAMONDS WITH FORMATION OF NANO-POROUS SILICON CARBIDE AT HIGH PRESSURE

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevsky

    2010-01-01

    Full Text Available The paper contains investigations on regularities of diamond - silicon carbide composite structure formation at impact-wave excitation. It has been determined that while squeezing a porous blank containing Si (SiC nano-diamond by explosive detonation products some processes are taking place such as diamond nano-particles consolidation, reverse diamond transition into graphite, fragments formation from silicon carbide. A method for obtaining high-porous composites with the presence of ultra-disperse diamond particles has been developed. Material with three-dimensional high-porous silicon-carbide structure has been received due to nano-diamond graphitation at impact wave transmission and plastic deformation. The paper reveals nano-diamonds inverse transformation into graphite and its subsequent interaction with the silicon accompanied by formation of silicon-carbide fragments with dimensions of up to 100 nm.

  8. Functionalization of 2D macroporous silicon under the high-pressure oxidation

    Science.gov (United States)

    Karachevtseva, L.; Kartel, M.; Kladko, V.; Gudymenko, O.; Bo, Wang; Bratus, V.; Lytvynenko, O.; Onyshchenko, V.; Stronska, O.

    2018-03-01

    Addition functionalization after high-pressure oxidation of 2D macroporous silicon structures is evaluated. X-ray diffractometry indicates formation of orthorhombic SiO2 phase on macroporous silicon at oxide thickness of 800-1200 nm due to cylindrical symmetry of macropores and high thermal expansion coefficient of SiO2. Pb center concentration grows with the splitting energy of LO- and TO-phonons and SiO2 thickness in oxidized macroporous silicon structures. This increase EPR signal amplitude and GHz radiation absorption and is promising for development of high-frequency devices and electronically controlled elements.

  9. Development of a Process for a High Capacity Arc Heater Production of Silicon for Solar Arrays

    Science.gov (United States)

    Reed, W. H.

    1979-01-01

    A program was established to develop a high temperature silicon production process using existing electric arc heater technology. Silicon tetrachloride and a reductant (sodium) are injected into an arc heated mixture of hydrogen and argon. Under these high temperature conditions, a very rapid reaction is expected to occur and proceed essentially to completion, yielding silicon and gaseous sodium chloride. Techniques for high temperature separation and collection were developed. Included in this report are: test system preparation; testing; injection techniques; kinetics; reaction demonstration; conclusions; and the project status.

  10. Study on high-silicon boron-containing zeolite by thermogravimetric and IR-spectroscopy techniques

    International Nuclear Information System (INIS)

    Chukin, G.D.; Nefedov, B.K.; Surin, S.A.; Polinina, E.V.; Khusid, B.L.; Sidel'kovskaya, V.G.

    1985-01-01

    The structure identity of initial Na-forms of boron-containing and aluminosilicate high-silicon zeolites is established by thermogravimetric and IR-spectroscopy methods. The presence of boron in Na-forms of high-silicon zeolites is shown to lead to reduction of structure thermal stability. It is noted that thermal stability of the H-form of both high-silicon boron-containing and boron-free zeolites is practically equal and considerably higher than that of Na-forms

  11. Frictional characteristics of silicon graphite lubricated with water at high pressure and high temperature

    International Nuclear Information System (INIS)

    Lee, Jae Seon; Kim, Eun Hyun; Park, Jin Seok; Kim, Jong In

    2001-01-01

    Experimental frictional and wear characteristics of silicon graphite materials is studied in this paper. Those specimens are lubricated with high temperature and highly pressurized water to simulate the same operating condition for the journal bearing and the thrust bearing on the main coolant pump bearing in the newly developing nuclear reactor named SMART(System-integrated Modular Advanced ReacTor). Operating condition of the bearings is realized by the tribometer and the autoclave. Friction coefficient and wear loss are analyzed to choose the best silicon graphite material. Pin on plate test specimens are used and coned disk springs are used to control the applied force on the specimens. Wear loss and wear width are measured by a precision balance and a micrometer. The friction force is measured by the strain gauge which can be used under high temperature and high pressure. Three kinds of silicon graphite materials are examined and compared with each other, and each material shows similar but different results on frictional and wear characteristics

  12. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    International Nuclear Information System (INIS)

    Lagov, P B; Drenin, A S; Zinoviev, M A

    2017-01-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding. (paper)

  13. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    Science.gov (United States)

    Lagov, P. B.; Drenin, A. S.; Zinoviev, M. A.

    2017-05-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding.

  14. Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics

    KAUST Repository

    Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

    2017-01-01

    A highly manufacturable deep reactive ion etching based process involving a hybrid soft/hard mask process technology shows high aspect ratio complex geometry Lego-like silicon electronics formation enabling free-form (physically flexible

  15. Crystal growth for high-efficiency silicon solar cells workshop: Summary

    Science.gov (United States)

    Dumas, K. A.

    1985-01-01

    The state of the art in the growth of silicon crystals for high-efficiency solar cells are reviewed, sheet requirements are defined, and furture areas of research are identified. Silicon sheet material characteristics that limit cell efficiencies and yields were described as well as the criteria for the ideal sheet-growth method. The device engineers wish list to the material engineer included: silicon sheet with long minority carrier lifetime that is uniform throughout the sheet, and which doesn't change during processing; and sheet material that stays flat throughout device processing, has uniform good mechanical strength, and is low cost. Impurities in silicon solar cells depreciate cell performance by reducing diffusion length and degrading junctions. The impurity behavior, degradation mechanisms, and variations in degradation threshold with diffusion length for silicon solar cells were described.

  16. High yield silicon carbide from alkylated or arylated pre-ceramic polymer

    International Nuclear Information System (INIS)

    Baney, R.H.; Gaul, J.H.

    1982-01-01

    Alkylated or arylated methylpolysilanes which exhibit ease of handling and are used to obtain silicon carbide ceramic materials in high yields contain 0 to 60 mole percent (CH 3 ) 2 Si double bond units and 40 to 100 mole percent CH 3 Si triple bond units, wherein there is also bonded to the silicon atoms other silicon atoms and additional alkyl radicals of 1 to 4 carbon atoms or phenyl. They may be prepared by reaction of a Grignard reagent RMgX, where X is halogen and R is Csub(1-4)-alkyl or phenyl, with a starting material which is a solid at 25 0 C, and is identical to the product except that the remaining bonds on the silicon atoms are attached to another silicon atom, or a chlorine or a bromine atom. Ceramics result from heating the polysilane products to 1200 0 C, optionally with fillers. (author)

  17. High impact ionization rate in silicon by sub-picosecond THz electric field pulses (Conference Presentation)

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Hirori, Hideki

    2017-01-01

    Summary form only given. Metallic antenna arrays fabricated on high resistivity silicon are used to localize and enhance the incident THz field resulting in high electric field pulses with peak electric field strength reaching several MV/cm on the silicon surface near the antenna tips. In such high...... electric field strengths high density of carriers are generated in silicon through impact ionization process. The high density of generated carriers induces a change of refractive index in silicon. By measuring the change of reflectivity of tightly focused 800 nm light, the local density of free carriers...... near the antenna tips is measured. Using the NIR probing technique, we observed that the density of carriers increases by over 8 orders of magnitude in a time duration of approximately 500 fs with an incident THz pulse of peak electric field strength 700 kV/cm. This shows that a single impact...

  18. Silicon Detector System for High Rate EXAFS Applications

    OpenAIRE

    Pullia, A.; Kraner, H. W.; Siddons, D. P.; Furenlid, L. R.; Bertuccio, G.

    1995-01-01

    A multichannel silicon pad detector for EXAFS (Extended X-ray Absorption Fine Structure) applications has been designed and built. The X-ray spectroscopic measurements demonstrate that an adequate energy resolution of 230 eV FWHM (corresponding to 27 rms electrons in silicon) can be achieved reliably at −35 °C. A resolution of 190 eV FWHM (corresponding to 22 rms electrons) has been obtained from individual pads at −35 °C. At room temperature (25 °C) an average energy resolution of 380 eV FWH...

  19. Dielectric elastomers, with very high dielectric permittivity, based on silicone and ionic interpenetrating networks

    DEFF Research Database (Denmark)

    Yu, Liyun; Madsen, Frederikke Bahrt; Hvilsted, Søren

    2015-01-01

    permittivity and the Young's modulus of the elastomer. One system that potentially achieves this involves interpenetrating polymer networks (IPNs), based on commercial silicone elastomers and ionic networks from amino- and carboxylic acid-functional silicones. The applicability of these materials as DEs...... are obtained while dielectric breakdown strength and Young's modulus are not compromised. These good overall properties stem from the softening effect and very high permittivity of ionic networks – as high as ε′ = 7500 at 0.1 Hz – while the silicone elastomer part of the IPN provides mechanical integrity...

  20. Neutron activation analysis of low-level element contents in silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Goerner, W [Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Berger, A [Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Niese, S [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany); Koehler, M [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany); Matthes, M [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany); Gawlik, D [Hahn-Meitner-Institut, Berlin (Germany)

    1997-03-01

    Semiconductor silicon is among the purest materials having ever been produced by modern technology. Thus, it is quite suitable as a primary reference material validating the correctness and the detection capabilities of developed analytical methods. Among them neutron activation analysis plays a competitive role. The U.S. National Institute of Science and Technology (NIST) has initiated and carried out an interlaboratory comparison in order to study the spread of analytical results worldwide evolved by several laboratories dealing with specimens of extreme purity. The outcome of the experiment was intended to review the capabilities of NAA as well as to differentiate between bulk and surface contamination. (orig./DG)

  1. The Silicon Valley Eco System. High-energetic in many ways; Het Silicon Valley Eco Systeem: hoogenergetisch in vele opzichten

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, J.

    2012-04-15

    The highly commended Silicon Valley Eco System is bubbling with energy with regard to the subjects that are focused upon, including sustainable energy, or the widely available expertise that is needed for the developments, good ideas, capital and optimism, fed by frequent examples of extraordinarily successful companies. The sheer endlessness of network opportunities joins all these elements frequently. This article addresses several noteworthy interactions in the field of sustainable energy over the last period. [Dutch] Het veel geroemde Silicon Valley eco systeem bruist van energie in de vorm van de onderwerpen waar men zich op richt, waaronder duurzame energie, of de ruim aanwezige expertise die nodig is voor de ontwikkelingen, goede ideeen, kapitaal, en optimisme, gevoed door regelmatige voorbeelden van buitensporig succesvolle bedrijven. De schier oneindige netwerkmogelijkheden brengen al deze elementen met grote regelmaat bij elkaar. In dit artikel volgen enkele vermeldenswaardige interacties op het vlak van duurzame energie uit de afgelopen periode.

  2. High-Sensitivity Temperature-Independent Silicon Photonic Microfluidic Biosensors

    Science.gov (United States)

    Kim, Kangbaek

    Optical biosensors that can precisely quantify the presence of specific molecular species in real time without the need for labeling have seen increased use in the drug discovery industry and molecular biology in general. Of the many possible optical biosensors, the TM mode Si biosensor is shown to be very attractive in the sensing application because of large field amplitude on the surface and cost effective CMOS VLSI fabrication. Noise is the most fundamental factor that limits the performance of sensors in development of high-sensitivity biosensors, and noise reduction techniques require precise studies and analysis. One such example stems from thermal fluctuations. Generally SOI biosensors are vulnerable to ambient temperature fluctuations because of large thermo-optic coefficient of silicon (˜2x10 -4 RIU/K), typically requiring another reference ring and readout sequence to compensate temperature induced noise. To address this problem, we designed sensors with a novel TM-mode shallow-ridge waveguide that provides both large surface amplitude for bulk and surface sensing. With proper design, this also provides large optical confinement in the aqueous cladding that renders the device athermal using the negative thermo-optic coefficient of water (~ --1x10-4RIU/K), demonstrating cancellation of thermo-optic effects for aqueous solution operation near 300K. Additional limitations resulting from mechanical actuator fluctuations, stability of tunable lasers, and large 1/f noise of lasers and sensor electronics can limit biosensor performance. Here we also present a simple harmonic feedback readout technique that obviates the need for spectrometers and tunable lasers. This feedback technique reduces the impact of 1/f noise to enable high-sensitivity, and a DSP lock-in with 256 kHz sampling rate can provide down to micros time scale monitoring for fast transitions in biomolecular concentration with potential for small volume and low cost. In this dissertation, a novel

  3. Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

    KAUST Repository

    Abdallah, Amir

    2017-09-22

    We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell\\'s configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.

  4. Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

    KAUST Repository

    Abdallah, Amir; Daif, Ounsi El; Aï ssa, Brahim; Kivambe, Maulid; Tabet, Nouar; Seif, Johannes; Haschke, Jan; Cattin, Jean; Boccard, Mathieu; De Wolf, Stefaan; Ballif, Christophe

    2017-01-01

    We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell's configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.

  5. Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

    KAUST Repository

    Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa

    2013-01-01

    (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree

  6. Improvements in numerical modelling of highly injected crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Altermatt, P.P. [University of New South Wales, Centre for Photovoltaic Engineering, 2052 Sydney (Australia); Sinton, R.A. [Sinton Consulting, 1132 Green Circle, 80303 Boulder, CO (United States); Heiser, G. [University of NSW, School of Computer Science and Engineering, 2052 Sydney (Australia)

    2001-01-01

    We numerically model crystalline silicon concentrator cells with the inclusion of band gap narrowing (BGN) caused by injected free carriers. In previous studies, the revised room-temperature value of the intrinsic carrier density, n{sub i}=1.00x10{sup 10}cm{sup -3}, was inconsistent with the other material parameters of highly injected silicon. In this paper, we show that high-injection experiments can be described consistently with the revised value of n{sub i} if free-carrier induced BGN is included, and that such BGN is an important effect in silicon concentrator cells. The new model presented here significantly improves the ability to model highly injected silicon cells with a high level of precision.

  7. TEM investigation of aluminium containing precipitates in high aluminium doped silicon carbide

    International Nuclear Information System (INIS)

    Wong-Leung, J.; FitzGerald, J.D.

    2002-01-01

    Full text: Silicon carbide is a promising semiconductor material for applications in high temperature and high power devices. The successful growth of good quality epilayers in this material has enhanced its potential for device applications. As a novel semiconductor material, there is a need for studying its basic physical properties and the role of dopants in this material. In this study, silicon carbide epilayers were grown on 4H-SiC wafers of (0001) orientation with a miscut angle of 8 deg at a temperature of 1550 deg C. The epilayers contained regions of high aluminium doping well above the solubility of aluminium in silicon carbide. High temperature annealing of this material resulted in the precipitation of aluminium in the wafers. The samples were analysed by secondary ion mass spectrometry and transmission electron microscopy. Selected area diffraction studies show the presence of aluminium carbide and aluminium silicon carbide phases. Copyright (2002) Australian Society for Electron Microscopy Inc

  8. Thermophysical Properties of Molten Silicon Measured by JPL High Temperature Electrostatic Levitator

    Science.gov (United States)

    Rhim, W. K.; Ohsaka, K.

    1999-01-01

    Five thermophysical properties of molten silicon measured by the High Temperature Electrostatic Levitator (HTESL) at JPL are presented. The properties measured are the density, the constant pressure specific heat capacity, the hemispherical total emissivity, the surface tension and the viscosity.

  9. Controlled localised melting in silicon by high dose germanium implantation and flash lamp annealing

    International Nuclear Information System (INIS)

    Voelskow, Matthias; Skorupa, Wolfgang; Pezoldt, Joerg; Kups, Thomas

    2009-01-01

    High intensity light pulse irradiation of monocrystalline silicon wafers is usually accompanied by inhomogeneous surface melting. The aim of the present work is to induce homogeneous buried melting in silicon by germanium implantation and subsequent flash lamp annealing. For this purpose high dose, high energy germanium implantation has been employed to lower the melting temperature of silicon in a predetermined depth region. Subsequent flash lamp irradiation at high energy densities leads to local melting of the germanium rich buried layer, whereby the thickness of the molten layer depends on the irradiation energy density. During the cooling down epitaxial crystallization takes place resulting in a largely defect-free layer. The combination of buried melting and dopant segregation has the potential to produce unusually buried doping profiles or to create strained silicon structures.

  10. Microarc Oxidation of the High-Silicon Aluminum AK12D Alloy

    Directory of Open Access Journals (Sweden)

    S. K. Kiseleva

    2015-01-01

    Full Text Available The aim of work is to study how the high-silicon aluminum AK12D alloy microstructure and MAO-process modes influence on characteristics (microhardness, porosity and thickness of the oxide layer of formed surface layer.Experimental methods of study:1 MAO processing of AK12D alloy disc-shaped samples. MAO modes features are concentration of electrolyte components – soluble water glass Na2SiO3 and potassium hydroxide (KOH. The content of two components both the soluble water glass and the potassium hydroxide was changed at once, with their concentration ratio remaining constant;2 metallographic analysis of AK12D alloy structure using an optical microscope «Olympus GX51»;3 image analysis of the system "alloy AK12D - MAO - layer" using a scanning electron microscope «JEOL JSM 6490LV»;4 hardness evaluation of the MAO-layers using a micro-hardness tester «Struers Duramin».The porosity, microhardness and thickness of MAO-layer formed on samples with different initial structures are analyzed in detail. Attention is paid to the influence of MAO process modes on the quality layer.It has been proved that the MAO processing allows reaching quality coverage with high microhardness values of 1200-1300HV and thickness up to 114 μm on high-silicon aluminum alloy. It has been found that the initial microstructure of alloy greatly affects the thickness of the MAO - layer. The paper explains the observed effect using the physical principles of MAO process and the nature of silicon particles distribution in the billet volume.It has been shown that increasing concentration of sodium silicate and potassium hydroxide in the electrolyte results in thicker coating and high microhardness.It has been revealed that high microhardness is observed in the thicker MAO-layers.Conclusions:1 The microstructure of aluminum AK12D alloy and concentration of electrolyte components - liquid glass Na2SiO3 and potassium hydroxide affect the quality of coating resulted from MAO

  11. Development of Silicon Sensor Characterization System for Future High Energy Physics Experiments

    OpenAIRE

    Preeti kumari; Kavita Lalwani; Ranjeet Dalal; Geetika Jain; Ashutosh Bhardwaj; Kirti Ranjan

    2015-01-01

    The Compact Muon Solenoid (CMS) is one of the general purpose experiments at the Large Hadron Collider (LHC), CERN and has its Tracker built of all silicon strip and pixel sensors. Si sensors are expected to play extremely important role in the upgrades of the existing Tracker for future high luminosity environment and will also be used in future lepton colliders. However, properties of the silicon sensors have to be carefully understood before they can be put in the extremely high luminos...

  12. Scaling of black silicon processing time by high repetition rate femtosecond lasers

    Directory of Open Access Journals (Sweden)

    Nava Giorgio

    2013-11-01

    Full Text Available Surface texturing of silicon substrates is performed by femtosecond laser irradiation at high repetition rates. Various fabrication parameters are optimized in order to achieve very high absorptance in the visible region from the micro-structured silicon wafer as compared to the unstructured one. A 70-fold reduction of the processing time is demonstrated by increasing the laser repetition rate from 1 kHz to 200 kHz. Further scaling up to 1 MHz can be foreseen.

  13. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    Science.gov (United States)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-10-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

  14. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    Science.gov (United States)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10–40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

  15. High-performance RF coil inductors on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Malba, V.; Young, D.; Ou, J.J.; Bernhardt, A.F.; Boser, B.E.

    1998-03-01

    Strong demand for wireless communication devices has motivated research directed toward monolithic integration of transceivers. The fundamental electronic component least compatible with silicon integrated circuits is the inductor, although a number of inductors are required to implement oscillators, filters and matching networks in cellular devices. Spiral inductors have been integrated into the silicon IC metallization sequence but have not performed adequately due to coupling to the silicon which results in parasitic capacitance and loss. We have, for the first time, fabricated three dimensional coil inductors on silicon which have significantly lower capacitive coupling and loss and which now exceed the requirements of potential applications. Quality factors of 30 at 1 GHz have been measured in single turn devices and Q > 16 in 2 and 4 turn devices. The reduced Q for multiturn devices appears to be related to eddy currents in outer turns generated by magnetic fields from current in neighboring turns. Higher Q values significantly in excess of 30 are anticipated using modified coil designs.

  16. Development of high efficiency solar cells on silicon web

    Science.gov (United States)

    Rohatgi, A.; Meier, D. L.; Campbell, R. B.; Schmidt, D. N.; Rai-Choudhury, P.

    1984-01-01

    Web base material is being improved with a goal toward obtaining solar cell efficiencies in excess of 18% (AM1). Carrier loss mechanisms in web silicon was investigated, techniques were developed to reduce carrier recombination in the web, and web cells were fabricated using effective surface passivation. The effect of stress on web cell performance was also investigated.

  17. Ultra-high-speed wavelength conversion in a silicon photonic chip

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Galili, Michael

    2011-01-01

    We have successfully demonstrated all-optical wavelength conversion of a 640-Gbit/s line-rate return-to-zero differential phase-shift keying (RZ-DPSK) signal based on low-power four wave mixing (FWM) in a silicon photonic chip with a switching energy of only ~110 fJ/bit. The waveguide dispersion...... of the silicon nanowire is nano-engineered to optimize phase matching for FWM and the switching power used for the signal processing is low enough to reduce nonlinear absorption from twophoton- absorption (TPA). These results demonstrate that high-speed wavelength conversion is achievable in silicon chips...

  18. Relaxation of the Shallow Acceptor Center Magnetic Moment in a Highly Doped Silicon

    CERN Document Server

    Mamedov, T N; Herlach, D; Gorelkin, V N; Gritsaj, K I; Duginov, V N; Kormann, O; Major, J V; Stoikov, A V; Zimmermann, U

    2001-01-01

    Results on the temperature dependence of the residual polarization of negative muons in crystalline silicon with germanium, boron and phosphorus impurities are presented. The measurements were carried out in a magnetic field of 0.1 T transverse to the direction of the muon spin in the temperature range 4.2-300 K. It is found that in a silicon sample with a high concentration of germanium impurity (9\\cdot 10^{19} cm^{-3}), as in the samples of n- and p-type silicon with impurity concentrations up to \\sim 10^{17} cm^{-3}, the relaxation rate \

  19. Silicon carbide production by Self-Propagating High Temperature (SHS) technique

    International Nuclear Information System (INIS)

    Lima, Eduardo de Souza; Schneider, Pedro Luiz; Mattoso, Irani Guedes; Costa, Carlos Roberto Correia da; Louro, Luis Henrique Leme

    1997-01-01

    Samples of silicon carbide (SiC) were synthesized from a mixture of silicon and carbon powders, using the Self-Propagating High Temperature Synthesis (SHS) technique. Three mixtures were tried, using silicon particles of the same average size but carbon particles of different average sizes. The method tried is characterized by an ignition temperature of 1450 deg C and the short duration of the synthesis ( 2-3 min). The samples were characterized by X-ray diffraction and scattering electron microscopy. (author)

  20. Silicon detectors for x and gamma-ray with high radiation resistance

    International Nuclear Information System (INIS)

    Cimpoca, Valerica; Popescu, Ion V.; Ruscu, Radu

    2001-01-01

    Silicon detectors are widely used in X and gamma-ray spectroscopy for direct detection or coupled with scintillators in high energy nuclear physics (modern collider experiments are representative), medicine and industrial applications. In X and gamma dosimetry, a low detection limit (under 6 KeV) with silicon detectors becomes available. Work at the room temperature is now possible due to the silicon processing evolution, which assures low reverse current and high life time of carriers. For several years, modern semiconductor detectors have been the primary choice for the measurement of nuclear radiation in various scientific fields. Nowadays the recently developed high resolution silicon detectors found their way in medical applications. As a consequence many efforts have been devoted to the development of high sensitivity and radiation hardened X and gamma-ray detectors for the energy range of 5 - 150 keV. The paper presents some results concerning the technology and behaviour of X and Gamma ray silicon detectors used in physics research, industrial and medical radiography. The electrical characteristics of these detectors, their modification after exposure to radiation and the results of spectroscopic X and Gamma-ray measurements are discussed. The results indicated that the proposed detectors enables the development of reliable silicon detectors to be used in controlling the low and high radiation levels encountered in a lot of application

  1. Fabrication of novel AFM probe with high-aspect-ratio ultra-sharp three-face silicon nitride tips

    NARCIS (Netherlands)

    Vermeer, Rolf; Berenschot, Johan W.; Sarajlic, Edin; Tas, Niels Roelof; Jansen, Henricus V.

    In this paper we present the wafer-scale fabrication of molded AFM probes with high aspect ratio ultra-sharp three-plane silicon nitride tips. Using $\\langle$111$\\rangle$ silicon wafers a dedicated process is developed to fabricate molds in the silicon wafer that have a flat triangular bottom

  2. Evolution of arsenic in high fluence plasma immersion ion implanted silicon : Behavior of the as-implanted surface

    NARCIS (Netherlands)

    Vishwanath, V.; Demenev, E.; Giubertoni, D.; Vanzetti, L.; Koh, A. L.; Steinhauser, G.; Pepponi, G.; Bersani, M.; Meirer, F.; Foad, M. A.

    2015-01-01

    High fluence (>1015 ions/cm2) low-energy (3 + on (1 0 0) silicon was investigated, with the focus on stability and retention of the dopant. At this dose, a thin (∼3 nm) amorphous layer forms at the surface, which contains about 45% arsenic (As) in a silicon and oxygen matrix. The presence of silicon

  3. EFFECT OF SILICON CONTENT ON MACHINABILITY OF Al-Si ALLOYS

    Directory of Open Access Journals (Sweden)

    Birol Akyüz

    2016-09-01

    Full Text Available In this study the effect of the change in the amount of Silicon (Si occuring in Al-Si alloys on mechanical and machinability properties of the alloy was investigated. The change in mechanical properties and microstructure, which depends on the increase in Si percentage, and the effects of this change on Flank Build-up (FBU, wear on the cutting edge, surface roughness, and machinability were also studied. Alloys in different ratios of Si (i.e. 2 to 12 wt %, were employed in the study. The specimens for tests were obtained by casting into metal moulds. The results obtained from experimental studies indicate improved mechanical properties and machinability, depending on the rise in Si percentage in Al-Si alloys. It is also observed that the increase in Si percentage enhanced surface quality.

  4. X- and gamma-ray N+PP+ silicon detectors with high radiation resistance

    International Nuclear Information System (INIS)

    Petris, M.; Ruscu, R.; Moraru, R.; Cimpoca, V.

    1998-01-01

    We have investigated the use of p-type silicon detectors as starting material for X-and gamma-ray detectors because of several potential benefits it would bring: 1. high purity p-type silicon grown by the float-zone process exhibits better radial dopant uniformity than n-type float-zone silicon; 2. it is free of radiation damage due to the neutron transmutation doping process and behaves better in a radiation field because mainly acceptor like centers are created through the exposure and the bulk material type inversion does not occur as in the n-type silicon. But the p-type silicon, in combination with a passivating layer of silicon dioxide, leads to a more complex detector layout since the positive charge in the oxide causes an inversion in the surface layer under the silicon dioxide. Consequently, it would be expected that N + P diodes have a higher leakage current than P + N ones. All these facts have been demonstrated experimentally. These features set stringent requirements for the technology of p-type silicon detectors. Our work presents two new geometries and an improved technology for p-type high resistivity material to obtain low noise radiation detectors. Test structures were characterized before and after the gamma exposure with a cumulative dose in the range 10 4 - 5 x 10 6 rad ( 60 Co). Results indicate that proposed structures and their technology enable the development of reliable N + PP + silicon detectors. For some samples (0.8 - 12 mm 2 ), extremely low reverse currents were obtained and, in combination with a low noise charge preamplifier, the splitting of 241 Am X-ray lines was possible and also the Mn Kα line (5.9 keV) was extracted from the noise with a 1.9 keV FWHM at the room temperature. An experimental model of a nuclear probe based on these diodes was designed for X-ray detection applications. (authors)

  5. Doping efficiency analysis of highly phosphorous doped epitaxial/amorphous silicon emitters grown by PECVD for high efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    El-Gohary, H.G.; Sivoththaman, S. [Waterloo Univ., ON (Canada). Dept. of Electrical and Computer Engineering

    2008-08-15

    The efficient doping of hydrogenated amorphous and crystalline silicon thin films is a key factor in the fabrication of silicon solar cells. The most popular method for developing those films is plasma enhanced chemical vapor deposition (PECVD) because it minimizes defect density and improves doping efficiency. This paper discussed the preparation of different structure phosphorous doped silicon emitters ranging from epitaxial to amorphous films at low temperature. Phosphine (PH{sub 3}) was employed as the doping gas source with the same gas concentration for both epitaxial and amorphous silicon emitters. The paper presented an analysis of dopant activation by applying a very short rapid thermal annealing process (RTP). A spreading resistance profile (SRP) and SIMS analysis were used to detect both the active dopant and the dopant concentrations, respectively. The paper also provided the results of a structural analysis for both bulk and cross-section at the interface using high-resolution transmission electron microscopy and Raman spectroscopy, for epitaxial and amorphous films. It was concluded that a unity doping efficiency could be achieved in epitaxial layers by applying an optimized temperature profile using short time processing rapid thermal processing technique. The high quality, one step epitaxial layers, led to both high conductive and high doping efficiency layers.

  6. Porous silicon structures with high surface area/specific pore size

    Science.gov (United States)

    Northrup, M.A.; Yu, C.M.; Raley, N.F.

    1999-03-16

    Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gases in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters. 9 figs.

  7. High temperature mechanical performance of a hot isostatically pressed silicon nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, A.A.; Ferber, M.K.; Jenkins, M.G.; Lin, C.K.J. [and others

    1996-01-01

    Silicon nitride ceramics are an attractive material of choice for designers and manufacturers of advanced gas turbine engine components for many reasons. These materials typically have potentially high temperatures of usefulness (up to 1400{degrees}C), are chemically inert, have a relatively low specific gravity (important for inertial effects), and are good thermal conductors (i.e., resistant to thermal shock). In order for manufacturers to take advantage of these inherent properties of silicon nitride, the high-temperature mechanical performance of the material must first be characterized. The mechanical response of silicon nitride to static, dynamic, and cyclic conditions at elevated temperatures, along with reliable and representative data, is critical information that gas turbine engine designers and manufacturers require for the confident insertion of silicon nitride components into gas turbine engines. This final report describes the high-temperature mechanical characterization and analyses that were conducted on a candidate structural silicon nitride ceramic. The high-temperature strength, static fatigue (creep rupture), and dynamic and cyclic fatigue performance were characterized. The efforts put forth were part of Work Breakdown Structure Subelement 3.2.1, {open_quotes}Rotor Data Base Generation.{close_quotes} PY6 is comparable to other hot isostatically pressed (HIPed) silicon nitrides currently being considered for advanced gas turbine engine applications.

  8. Impurity effects in silicon for high efficiency solar cells

    Science.gov (United States)

    Hopkins, R. H.; Rohatgi, A.

    1986-01-01

    Model analyses indicate that sophisticated solar cell designs including, e.g., back surface fields, optical reflectors, surface passivation, and double layer antireflective coatings can produce devices with conversion efficiencies above 20 percent (AM1). To realize this potential, the quality of the silicon from which the cells are made must be improved; and these excellent electrical properties must be maintained during device processing. As the cell efficiency rises, the sensitivity to trace contaminants also increases. For example, the threshold Ti impurity concentration at which cell performance degrades is more than an order of magnitude lower for an 18-percent cell. Similar behavior occurs for numerous other metal species which introduce deep level traps that stimulate the recombination of photogenerated carriers in silicon. Purification via crystal growth in conjunction with gettering steps to preserve the large diffusion length of the as-grown material can lead to the production of devices with efficiencies aboved 18 percent, as has been verified experimentally.

  9. Silicon Detector System for High Rate EXAFS Applications.

    Science.gov (United States)

    Pullia, A; Kraner, H W; Siddons, D P; Furenlid, L R; Bertuccio, G

    1995-08-01

    A multichannel silicon pad detector for EXAFS (Extended X-ray Absorption Fine Structure) applications has been designed and built. The X-ray spectroscopic measurements demonstrate that an adequate energy resolution of 230 eV FWHM (corresponding to 27 rms electrons in silicon) can be achieved reliably at -35 °C. A resolution of 190 eV FWHM (corresponding to 22 rms electrons) has been obtained from individual pads at -35 °C. At room temperature (25 °C) an average energy resolution of 380 eV FWHM is achieved and a resolution of 350 eV FWHM (41 rms electrons) is the best performance. A simple cooling system constituted of Peltier cells is sufficient to reduce the reverse currents of the pads and their related shot noise contribution, in order to achieve resolutions better than 300 eV FWHM which is adequate for the EXAFS applications.

  10. High resolution silicon detectors for colliding beam physics

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Bedeschi, F.; Bertolucci, E.; Bettoni, D.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Dell'Orso, M.; Fidecaro, F.; Foa, L.; Focardi, E.; Giannetti, P.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Raso, G.; Ristori, L.; Scribano, A.; Stefanini, A.; Tenchini, R.; Tonelli, G.; Triggiani, G.

    1984-01-01

    Resolution and linearity of the position measurement of Pisa multi-electrode silicon detectors are presented. The detectors are operated in slightly underdepleted mode and take advantage of their intrinsic resistivity for resistive charge partition between adjacent strips. 22 μm resolution is achieved with readout lines spaced 300 μm. Possible applications in colliding beam experiments for the detection of secondary vertices are discussed. (orig.)

  11. High Power Broadband Multispectral Source on a Hybrid Silicon Chip

    Science.gov (United States)

    2017-03-14

    optical bandwidth of the erbium-doped- fiber -amplifier with densely-spaced frequency channels. To extend the spectral capacity of the Si-on-insulator...associated with non-uniform undercut at the taper tip across the chip after wet etching the active region. Figure 14. Normalized optical emission...Hutchinson, J., Shin, J.-H., Fish, G., and Fang, A., “Integrated silicon photonic laser sources for telecom and datacom,” in [National Fiber Optic

  12. Operation of a high-purity silicon diode alpha particle detector at 1. 4 K

    Energy Technology Data Exchange (ETDEWEB)

    Martoff, C.J.; Kaczanowicz, E. (Temple Univ., Philadelphia, PA (USA)); Neuhauser, B.J.; Lopez, E.; Zhang, Y. (San Francisco State Univ., CA (USA)); Ziemba, F.P. (Quantrad Corp. (USA))

    1991-03-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm{sup 2} by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.).

  13. Silicon dioxide with a silicon interfacial layer as an insulating gate for highly stable indium phosphide metal-insulator-semiconductor field effect transistors

    Science.gov (United States)

    Kapoor, V. J.; Shokrani, M.

    1991-01-01

    A novel gate insulator consisting of silicon dioxide (SiO2) with a thin silicon (Si) interfacial layer has been investigated for high-power microwave indium phosphide (InP) metal-insulator-semiconductor field effect transistors (MISFETs). The role of the silicon interfacial layer on the chemical nature of the SiO2/Si/InP interface was studied by high-resolution X-ray photoelectron spectroscopy. The results indicated that the silicon interfacial layer reacted with the native oxide at the InP surface, thus producing silicon dioxide, while reducing the native oxide which has been shown to be responsible for the instabilities in InP MISFETs. While a 1.2-V hysteresis was present in the capacitance-voltage (C-V) curve of the MIS capacitors with silicon dioxide, less than 0.1 V hysteresis was observed in the C-V curve of the capacitors with the silicon interfacial layer incorporated in the insulator. InP MISFETs fabricated with the silicon dioxide in combination with the silicon interfacial layer exhibited excellent stability with drain current drift of less than 3 percent in 10,000 sec, as compared to 15-18 percent drift in 10,000 sec for devices without the silicon interfacial layer. High-power microwave InP MISFETs with Si/SiO2 gate insulators resulted in an output power density of 1.75 W/mm gate width at 9.7 GHz, with an associated power gain of 2.5 dB and 24 percent power added efficiency.

  14. Characterization of silane reduced CVD tungsten films with respect to silicon content

    International Nuclear Information System (INIS)

    Suzuki, M.; Kobayashi, N.; Makai, K.

    1990-01-01

    Tungsten (W) films grown by LPCVD using WF 6 and SiH 4 are characterized with respect to Si content ([Si]) in the film. The Si content was influenced by the deposition temperature as well as the flow ratio of WF 6 /SiH 4 . The electrical resistance, film stress, and film composition of as-deposited films are categorized by [Si] into three groups: [Si] ≤ 2 atm%, 2 ≤ [Si] 40 atm%. When [Si] ≤ 2 atm%, the electrical resistance is almost proportional to [Si], and it is mainly determined by the impurity scattering of Si. In this [Si] region, W can be selectively deposited on Si. On the other hand, when 2 ≤ [Si] 20-40 atm%, the electrical resistance is only slightly affected by Si content, and its temperature dependence is peculiar to semiconductors. When [Si] > 40 atm%, the microcrystals of WSi 2 begins to form in the film

  15. Synthesis of high-quality mesoporous silicon particles for enhanced lithium storage performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chundong, E-mail: apcdwang@hust.edu.cn [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Ren, Jianguo [Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Chen, Hao [Department of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou (China); Zhang, Yi [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan, 430073 (China); Ostrikov, Kostya [School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, QLD (Australia); Manufacturing Flagship, CSIRO, P. O. Box 218, Lindfield, NSW 2070 (Australia); Zhang, Wenjun [Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Li, Yi, E-mail: liyi@suda.edu.cn [Department of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou (China); Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China)

    2016-04-15

    Silicon has been considered as one of the most promising anode materials for high-capacity lithium-ion batteries (LIBs) due to its ultrahigh theoretical capacity, abundance, and environmentally benign nature. Nonetheless, the severe break during the prolonged cycling results in poor electrochemical performance, which hinders its practical application. Herein, we report the synthesis of novel mesoporous silicon particles with a facile template method by using a magnesiothermic reduction for LIBs. The obtained silicon nanoparticles are highly porous with densely porous cavities (20–40 nm) on the wall, of which it presents good crystallization. Electrochemical measurements showed that the mesoporous silicon nanoparticles delivered a high reversible specific capacity of 910 mA h g{sup −1} at a high current density of 1200 mA g{sup −1} over 50 cycles. The specific capacity at such high current density is still over twofold than that of commercial graphite anode, suggesting that the nanoporous Si architectures is suitable for high-performance Si-based anodes for lithium ion batteries in terms of capacity, cycle life, and rate capacity. - Highlights: • Silica nanotubes were prepared with a facile template method. • Novel mesoporous silicon particles were obtained by magnesiothermic reduction. • High-Performance LIBs were achieved by using mesoporous Si particle Electrodes.

  16. Silicon nanowire structures as high-sensitive pH-sensors

    International Nuclear Information System (INIS)

    Belostotskaya, S O; Chuyko, O V; Kuznetsov, A E; Kuznetsov, E V; Rybachek, E N

    2012-01-01

    Sensitive elements for pH-sensors created on silicon nanostructures were researched. Silicon nanostructures have been used as ion-sensitive field effect transistor (ISFET) for the measurement of solution pH. Silicon nanostructures have been fabricated by 'top-down' approach and have been studied as pH sensitive elements. Nanowires have the higher sensitivity. It was shown, that sensitive element, which is made of 'one-dimensional' silicon nanostructure have bigger pH-sensitivity as compared with 'two-dimensional' structure. Integrated element formed from two p- and n-type nanowire ISFET ('inverter') can be used as high sensitivity sensor for local relative change [H+] concentration in very small volume.

  17. Preparation of highly aligned silicon oxide nanowires with stable intensive photoluminescence

    International Nuclear Information System (INIS)

    Duraia, El-Shazly M.; Mansurov, Z.A.; Tokmolden, S.; Beall, Gary W.

    2010-01-01

    In this work we report the successful formation of highly aligned vertical silicon oxide nanowires. The source of silicon was from the substrate itself without any additional source of silicon. X-ray measurement demonstrated that our nanowires are amorphous. Photoluminescence measurements were conducted through 18 months and indicated that there is a very good intensive emission peaks near the violet regions. The FTIR measurements indicated the existence of peaks at 463, 604, 795 and a wide peak at 1111 cm -1 and this can be attributed to Si-O-Si and Si-O stretching vibrations. We also report the formation of the octopus-like silicon oxide nanowires and the growth mechanism of these structures was discussed.

  18. Preparation of highly aligned silicon oxide nanowires with stable intensive photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Duraia, El-Shazly M., E-mail: duraia_physics@yahoo.co [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Al-Farabi Kazakh National University, Almaty (Kazakhstan); Institute of Physics and Technology, 11 Ibragimov Street, 050032 Almaty (Kazakhstan); Mansurov, Z.A. [Al-Farabi Kazakh National University, Almaty (Kazakhstan); Tokmolden, S. [Institute of Physics and Technology, 11 Ibragimov Street, 050032 Almaty (Kazakhstan); Beall, Gary W. [Texas State University-San Marcos, Department of Chemistry and Biochemistry, 601 University Dr., San Marcos, TX 78666 (United States)

    2010-02-15

    In this work we report the successful formation of highly aligned vertical silicon oxide nanowires. The source of silicon was from the substrate itself without any additional source of silicon. X-ray measurement demonstrated that our nanowires are amorphous. Photoluminescence measurements were conducted through 18 months and indicated that there is a very good intensive emission peaks near the violet regions. The FTIR measurements indicated the existence of peaks at 463, 604, 795 and a wide peak at 1111 cm{sup -1} and this can be attributed to Si-O-Si and Si-O stretching vibrations. We also report the formation of the octopus-like silicon oxide nanowires and the growth mechanism of these structures was discussed.

  19. High performance SONOS flash memory with in-situ silicon nanocrystals embedded in silicon nitride charge trapping layer

    Science.gov (United States)

    Lim, Jae-Gab; Yang, Seung-Dong; Yun, Ho-Jin; Jung, Jun-Kyo; Park, Jung-Hyun; Lim, Chan; Cho, Gyu-seok; Park, Seong-gye; Huh, Chul; Lee, Hi-Deok; Lee, Ga-Won

    2018-02-01

    In this paper, SONOS-type flash memory device with highly improved charge-trapping efficiency is suggested by using silicon nanocrystals (Si-NCs) embedded in silicon nitride (SiNX) charge trapping layer. The Si-NCs were in-situ grown by PECVD without additional post annealing process. The fabricated device shows high program/erase speed and retention property which is suitable for multi-level cell (MLC) application. Excellent performance and reliability for MLC are demonstrated with large memory window of ∼8.5 V and superior retention characteristics of 7% charge loss for 10 years. High resolution transmission electron microscopy image confirms the Si-NC formation and the size is around 1-2 nm which can be verified again in X-ray photoelectron spectroscopy (XPS) where pure Si bonds increase. Besides, XPS analysis implies that more nitrogen atoms make stable bonds at the regular lattice point. Photoluminescence spectra results also illustrate that Si-NCs formation in SiNx is an effective method to form deep trap states.

  20. Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

    Science.gov (United States)

    Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

    2014-10-28

    Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

  1. High Aspect Ratio Sub-15 nm Silicon Trenches From Block Copolymer Templates

    Science.gov (United States)

    Gu, Xiaodan; Liu, Zuwei; Gunkel, Ilja; Olynick, Deirdre; Russell, Thomas; University of Massachusetts Amherst Collaboration; Oxford Instrument Collaboration; Lawrence Berkeley National Lab Collaboration

    2013-03-01

    High-aspect-ratio sub-15 nm silicon trenches are fabricated directly from plasma etching of a block copolymer (BCP) mask. Polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) 40k-b-18k was spin coated and solvent annealed to form cylindrical structures parallel to the silicon substrate. The BCP thin film was reconstructed by immersion in ethanol and then subjected to an oxygen and argon reactive ion etching to fabricate the polymer mask. A low temperature ion coupled plasma with sulfur hexafluoride and oxygen was used to pattern transfer block copolymer structure to silicon with high selectivity (8:1) and fidelity. The silicon pattern was characterized by scanning electron microscopy and grazing incidence x-ray scattering. We also demonstrated fabrication of silicon nano-holes using polystyrene-b-polyethylene oxide (PS-b-PEO) using same methodology described above for PS-b-P2VP. Finally, we show such silicon nano-strucutre serves as excellent nano-imprint master template to pattern various functional materials like poly 3-hexylthiophene (P3HT).

  2. Metallurgical structures in a high uranium-silicon alloy

    International Nuclear Information System (INIS)

    Wyatt, B.S.; Berthiaume, L.C.; Conversi, J.L.

    1968-10-01

    The effects of fabrication and heat treatment variables on the structure of a uranium -- 3.96 wt% silicon alloy have been studied using optical microscopy, quantitative metallography and hardness determinations. It has been shown that an optimum temperature exists below the peritectoid temperature where the maximum amount of transformation to U 3 Si occurs in a given period of time. The time required to fully transform an as-cast alloy at this optimum temperature is affected by the size of the primary U 3 Si 2 dendrites. With a U 3 Si 2 particle size of <12 μm complete transformation can be achieved in four hours. (author)

  3. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

    Science.gov (United States)

    2015-07-21

    Hybrid Biosensor Jieun Lee1,2, Jaeman Jang1, Bongsik Choi1, Jinsu Yoon1, Jee-Yeon Kim3, Yang-Kyu Choi3, Dong Myong Kim1, Dae Hwan Kim1 & Sung-Jin Choi1...This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response...of field-effect-transistor (FET)-based biosensors . The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential

  4. New sunflower seeds with high contents of phytosterols

    Directory of Open Access Journals (Sweden)

    Velasco Leonardo

    2014-11-01

    Full Text Available Dietary phytosterols have a positive nutritional impact because they contribute to reduce cholesterol levels in blood. Accordingly, foods rich in phytosterols are required in a healthy diet. Vegetable oils are the richest source of phytosterols in the diet, though sunflower oil has lower phytosterol content than other seed oils such as rapeseed and corn. Increasing phytosterol content in sunflower oil requires optimizing first selection procedures. In this way, the development of accurate methods for analyzing phytosterol content in seeds instead of oils has opened up recently the way for large-scale screening for this trait. Large variability for seed phytosterol content has been identified in sunflower germplasm, from which we have developed a line, IASP-18, with about twofold seed phytosterol content than conventional sunflower. The trait is expressed across environments. Genetic studies are underway to characterize its inheritance and assess the feasibility of introgressing genes for high phytosterol content into elite sunflower germplasm.

  5. Metallurgy of high-silicon steel parts produced using Selective Laser Melting

    International Nuclear Information System (INIS)

    Garibaldi, Michele; Ashcroft, Ian; Simonelli, Marco; Hague, Richard

    2016-01-01

    The metallurgy of high-silicon steel (6.9%wt.Si) processed using Selective Laser Melting (SLM) is presented for the first time in this study. High-silicon steel has great potential as a soft magnetic alloy, but its employment has been limited due to its poor workability. The effect of SLM-processing on the metallurgy of the alloy is investigated in this work using microscopy, X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD). XRD analysis suggests that the SLM high-silicon steel is a single ferritic phase (solid solution), with no sign of phase ordering. This is expected to have beneficial effects on the material properties, since ordering has been shown to make silicon steels more brittle and electrically conductive. For near-fully dense samples, columnar grains with a high aspect ratio and oriented along the build direction are found. Most importantly, a <001> fibre-texture along the build direction can be changed into a cube-texture when the qualitative shape of the melt-pool is altered (from shallow to deep) by increasing the energy input of the scanning laser. This feature could potentially open the path to the manufacture of three-dimensional grain-oriented high-silicon steels for electromechanical applications.

  6. High precision silicon piezo resistive SMART pressure sensor

    International Nuclear Information System (INIS)

    Brown, Rod

    2005-01-01

    Instruments for test and calibration require a pressure sensor that is precise and stable. Market forces also dictate a move away from single measurand test equipment and, certainly in the case of pressure, away from single range equipment. A pressure 'module' is required which excels in pressure measurement but is interchangble with sensors for other measurands. A communications interface for such a sensor has been specified. Instrument Digital Output Sensor (IDOS) that permits this interchanagability and allows the sensor to be inside or outside the measuring instrument. This paper covers the design and specification of a silicon diaphragm piezo resistive SMART sensor using this interface. A brief history of instrument sensors will be given to establish the background to this development. Design choices of the silicon doping, bridge energisation method, temperature sensing, signal conversion, data processing, compensation method, communications interface will be discussed. The physical format of the 'in-instrument' version will be shown and then extended to the packaging design for the external version. Test results will show the accuracy achieved exceeds the target of 0.01%FS over a range of temperatures

  7. High precision silicon piezo resistive SMART pressure sensor

    Science.gov (United States)

    Brown, Rod

    2005-01-01

    Instruments for test and calibration require a pressure sensor that is precise and stable. Market forces also dictate a move away from single measurand test equipment and, certainly in the case of pressure, away from single range equipment. A pressure `module' is required which excels in pressure measurement but is interchangble with sensors for other measurands. A communications interface for such a sensor has been specified. Instrument Digital Output Sensor (IDOS) that permits this interchanagability and allows the sensor to be inside or outside the measuring instrument. This paper covers the design and specification of a silicon diaphragm piezo resistive SMART sensor using this interface. A brief history of instrument sensors will be given to establish the background to this development. Design choices of the silicon doping, bridge energisation method, temperature sensing, signal conversion, data processing, compensation method, communications interface will be discussed. The physical format of the `in-instrument' version will be shown and then extended to the packaging design for the external version. Test results will show the accuracy achieved exceeds the target of 0.01%FS over a range of temperatures.

  8. Determinations of silicon and phosphorus in rice planted on a district of high incidence of amyotrophic lateral sclerosis by neutron activation and X-ray fluorescence analyses

    International Nuclear Information System (INIS)

    Mizumoto, Yoshihiko; Ishikawa, Teruumi; Kusakabe, Toshio; Katsurayama, Kousuke; Iwata, Shiro.

    1989-01-01

    Silicon and phosphorus contents in polished and unpolished rice planted on a district of high incidence of amyotrophic lateral sclerosis (ALS) have been determined by neutron activation and X-ray fluorescence methods, and compared with those from control areas. In the neutron activation analysis, β-ray spectra of 32 P produced by the 31 P(n, γ) 32 P reaction on polished and unpolished rice were measured with a low background β-ray spectrometer. In the X-ray fluorescence analysis, characteristic X-ray were analyzed with a wavelength dispersive X-ray fluorescence spectrometer. Silicon contents in polished and unpolished rice from the ALS area are 42 μg.g -1 and 370 μg.g -1 , respectively, and the corresponding phosphorus contents are 1210 μg.g -1 , and 3370 μg.g -1 , respectively. The data for ALS area are equal to those for the control area within atandard deviation. (author)

  9. High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices

    Science.gov (United States)

    Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

    2014-01-01

    A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

  10. Influence of Austempering Heat Treatment on Microstructure and Mechanical Properties of Medium Carbon High Silicon Steel

    Science.gov (United States)

    Palaksha, P. A.; Ravishankar, K. S.

    2017-08-01

    In the present investigation, the influence of austempering heat treatment on the microstructure and mechanical properties of medium carbon high silicon steel was evaluated. The test specimens were machined from the as-received steel and were first austenitised at 900 °C for 45 minutes, followed by austempering heat treatment in salt bath at various temperatures 300 °C, 350 °C and 400 °C for a fixed duration of two hours, after that those specimens were air-cooled to room temperature. The characterization studies were carried out using optical microscope, scanning electron microscope (SEM) and x-ray diffractometer (XRD) and then correlated to the hardness and tensile properties. Results indicate that, the specimens austempered at lower temperature i.e. at 300 °C, which offered high hardness, tensile strength and lower ductility (1857 MPa and 13.3 %) due to the presence of acicular bainite i.e. lower bainite and also some martensite in the microstructure. At 350 °C, reduction in the tensile strength and hardness was observed, but comparatively higher ductility, which was favored by the presence of bainite laths i.e. upper bainitic structure along with higher retained austenite content. Finally at 400 °C, reduction in both ductility and tensile strength was observed, which is due to the precipitation of carbides between the banite laths, however good strain hardening response was observed at austempering temperatures of 350 °C and 400 °C.

  11. Analysis of heating effect on the process of high deposition rate microcrystalline silicon

    International Nuclear Information System (INIS)

    Xiao-Dan, Zhang; He, Zhang; Chang-Chun, Wei; Jian, Sun; Guo-Fu, Hou; Shao-Zhen, Xiong; Xin-Hua, Geng; Ying, Zhao

    2010-01-01

    A possible heating effect on the process of high deposition rate microcrystalline silicon has been studied. It includes the discharge time-accumulating heating effect, discharge power, inter-electrode distance, and total gas flow rate induced heating effect. It is found that the heating effects mentioned above are in some ways quite similar to and in other ways very different from each other. However, all of them will directly or indirectly cause the increase of the substrate surface temperature during the process of depositing microcrystalline silicon thin films, which will affect the properties of the materials with increasing time. This phenomenon is very serious for the high deposition rate of microcrystalline silicon thin films because of the high input power and the relatively small inter-electrode distance needed. Through analysis of the heating effects occurring in the process of depositing microcrystalline silicon, it is proposed that the discharge power and the heating temperature should be as low as possible, and the total gas flow rate and the inter-electrode distance should be suitable so that device-grade high quality deposition rate microcrystalline silicon thin films can be fabricated

  12. A high volume cost efficient production macrostructuring process. [for silicon solar cell surface treatment

    Science.gov (United States)

    Chitre, S. R.

    1978-01-01

    The paper presents an experimentally developed surface macro-structuring process suitable for high volume production of silicon solar cells. The process lends itself easily to automation for high throughput to meet low-cost solar array goals. The tetrahedron structure observed is 0.5 - 12 micron high. The surface has minimal pitting with virtually no or very few undeveloped areas across the surface. This process has been developed for (100) oriented as cut silicon. Chemi-etched, hydrophobic and lapped surfaces were successfully texturized. A cost analysis as per Samics is presented.

  13. Microscopic mechanism of amino silicone oil modification and modification effect with different amino group contents based on molecular dynamics simulation

    Science.gov (United States)

    He, Liping; Li, Wenjun; Chen, Dachuan; Yuan, Jianmin; Lu, Gang; Zhou, Dianwu

    2018-05-01

    The microscopic mechanism of amino silicone oil (ASO) modification of natural fiber was investigated for the first time using molecular dynamics (MD) simulation at the atomic and molecular levels. The MD simulation results indicated that the ASO molecular interacted with the cellulose molecular within the natural fiber, mainly by intermolecular forces of Nsbnd Hsbnd O and Osbnd Hsbnd N hydrogen bonds and the molecular chain of ASO absorbed onto the natural fiber in a selective orientation, i.e., the hydrophobic alkyl groups (sbnd CnH2n+1) project outward and the polar amino groups (sbnd NH2) point to the surface of natural fiber. Consequently, the ASO modification changed the surface characteristic of natural fiber from hydrophilic to hydrophobic. Furthermore, the modification effects of the ASO modification layer with different amino group contents (m:n ratio) were also evaluated in this study by calculating the binding energy between the ASO modifier and natural fiber, and the cohesive energy density and free volume of the ASO modification layer. The results showed that the binding energy reached a maximum when the m:n ratio of ASO was of 8:4, suggesting that a good bonding strength was achieved at this m:n ratio. It was also found that the cohesive energy density enhanced with the increase in the amino group content, and the higher the cohesive energy density, the easier the formation of the ASO modification layer. However, the fraction free volume decreased with the increase in the amino group content. This is good for improving the water-proof property of natural fiber. The present work can provide an effective method for predicting the modification effects and designing the optimized m:n ratio of ASO modification.

  14. High quality silicon-based substrates for microwave and millimeter wave passive circuits

    Science.gov (United States)

    Belaroussi, Y.; Rack, M.; Saadi, A. A.; Scheen, G.; Belaroussi, M. T.; Trabelsi, M.; Raskin, J.-P.

    2017-09-01

    Porous silicon substrate is very promising for next generation wireless communication requiring the avoidance of high-frequency losses originating from the bulk silicon. In this work, new variants of porous silicon (PSi) substrates have been introduced. Through an experimental RF performance, the proposed PSi substrates have been compared with different silicon-based substrates, namely, standard silicon (Std), trap-rich (TR) and high resistivity (HR). All of the mentioned substrates have been fabricated where identical samples of CPW lines have been integrated on. The new PSi substrates have shown successful reduction in the substrate's effective relative permittivity to values as low as 3.7 and great increase in the substrate's effective resistivity to values higher than 7 kΩ cm. As a concept proof, a mm-wave bandpass filter (MBPF) centred at 27 GHz has been integrated on the investigated substrates. Compared with the conventional MBPF implemented on standard silicon-based substrates, the measured S-parameters of the PSi-based MBPF have shown high filtering performance, such as a reduction in insertion loss and an enhancement of the filter selectivity, with the joy of having the same filter performance by varying the temperature. Therefore, the efficiency of the proposed PSi substrates has been well highlighted. From 1994 to 1995, she was assistant of physics at (USTHB), Algiers . From 1998 to 2011, she was a Researcher at characterization laboratory in ionized media and laser division at the Advanced Technologies Development Center. She has integrated the Analog Radio Frequency Integrated Circuits team as Researcher since 2011 until now in Microelectronic and Nanotechnology Division at Advanced Technologies Development Center (CDTA), Algiers. She has been working towards her Ph.D. degree jointly at CDTA and Ecole Nationale Polytechnique, Algiers, since 2012. Her research interest includes fabrication and characterization of microwave passive devices on porous

  15. N-Type delta Doping of High-Purity Silicon Imaging Arrays

    Science.gov (United States)

    Blacksberg, Jordana; Hoenk, Michael; Nikzad, Shouleh

    2005-01-01

    A process for n-type (electron-donor) delta doping has shown promise as a means of modifying back-illuminated image detectors made from n-doped high-purity silicon to enable them to detect high-energy photons (ultraviolet and x-rays) and low-energy charged particles (electrons and ions). This process is applicable to imaging detectors of several types, including charge-coupled devices, hybrid devices, and complementary metal oxide/semiconductor detector arrays. Delta doping is so named because its density-vs.-depth characteristic is reminiscent of the Dirac delta function (impulse function): the dopant is highly concentrated in a very thin layer. Preferably, the dopant is concentrated in one or at most two atomic layers in a crystal plane and, therefore, delta doping is also known as atomic-plane doping. The use of doping to enable detection of high-energy photons and low-energy particles was reported in several prior NASA Tech Briefs articles. As described in more detail in those articles, the main benefit afforded by delta doping of a back-illuminated silicon detector is to eliminate a "dead" layer at the back surface of the silicon wherein high-energy photons and low-energy particles are absorbed without detection. An additional benefit is that the delta-doped layer can serve as a back-side electrical contact. Delta doping of p-type silicon detectors is well established. The development of the present process addresses concerns specific to the delta doping of high-purity silicon detectors, which are typically n-type. The present process involves relatively low temperatures, is fully compatible with other processes used to fabricate the detectors, and does not entail interruption of those processes. Indeed, this process can be the last stage in the fabrication of an imaging detector that has, in all other respects, already been fully processed, including metallized. This process includes molecular-beam epitaxy (MBE) for deposition of three layers, including

  16. Silicon content design of CrSiN films for good anti-corrosion and anti-wear performances in NaOH solution

    Science.gov (United States)

    Wang, Haixin; Ye, Yuwei; Wang, Chunting; Zhang, Guangan; Liu, Wei

    2018-06-01

    The CrSiN films with different silicon contents were fabricated by medium frequency magnetron sputtering. The 304L stainless steel and Si (1 0 0) wafer were used for substrate specimens. Film plasticity, corrosion and tribological behaviors in 0.1 M NaOH solution were systematically investigated. Results show that the plasticity of CrN film could be improved by the addition of silicon. During the corrosion test, with the increase of silicon content, the corrosion current density exhibited a descending trend and impedance presented a rising trend. The COF and wear rate of as-prepared CrSiN film initially decreased and then increased as the silicon content increased. The CrSiN film with 12.7 at.% Si exhibited the lowest COF of 0.04 and a wear rate of 6.746  ×  10‑8 mm3 Nm‑1 in 0.1 M NaOH solution.

  17. Determination of silicon and chromium content in gray cast iron by the Van der Pauw method; Determinacion del contenido de silicio y cromo en fundiciones grises mediante el metodo de Van der Pauw

    Energy Technology Data Exchange (ETDEWEB)

    Tremps, E.; Enrique, J. L.; Moron, C.; Garcia, A.; Gomez, A.

    2013-07-01

    In this paper we show a system based on the resistivity measurement of samples of gray cast iron by the Van der Pauw method to calculate the silicon content in the samples. Twenty five trials have been carried out, studying resistive and metallographic characteristics of the samples. This has demonstrated that it is possible to obtain, by this method, the silicon content in molten flat with low content of alloying elements, also the content of chromium in series smelters where the rate of silicon remains constant. (Author)

  18. Ultra-High Capacity Silicon Photonic Interconnects through Spatial Multiplexing

    Science.gov (United States)

    Chen, Christine P.

    The market for higher data rate communication is driving the semiconductor industry to develop new techniques of writing at smaller scales, while continuing to scale bandwidth at low power consumption. Silicon photonic (SiPh) devices offer a potential solution to the electronic interconnect bandwidth bottleneck. SiPh leverages the technology commensurate of decades of fabrication development with the unique functionality of next-generation optical interconnects. Finer fabrication techniques have allowed for manufacturing physical characteristics of waveguide structures that can support multiple modes in a single waveguide. By refining modal characteristics in photonic waveguide structures, through mode multiplexing with the asymmetric y-junction and microring resonator, higher aggregate data bandwidth is demonstrated via various combinations of spatial multiplexing, broadening applications supported by the integrated platform. The main contributions of this dissertation are summarized as follows. Experimental demonstrations of new forms of spatial multiplexing combined together exhibit feasibility of data transmission through mode-division multiplexing (MDM), mode-division and wavelength-division multiplexing (MDM-WDM), and mode-division and polarization-division multiplexing (MDM-PDM) through a C-band, Si photonic platform. Error-free operation through mode multiplexers and demultiplexers show how data can be viably scaled on multiple modes and with existing spatial domains simultaneously. Furthermore, we explore expanding device channel support from two to three arms. Finding that a slight mismatch in the third arm can increase crosstalk contributions considerably, especially when increasing data rate, we explore a methodical way to design the asymmetric y-junction device by considering its angles and multiplexer/demultiplexer arm width. By taking into consideration device fabrication variations, we turn towards optimizing device performance post

  19. Electrothermal Behavior of High-Frequency Silicon-On-Glass Transistors

    NARCIS (Netherlands)

    Nenadovic, N.

    2004-01-01

    In this thesis, research is focused on the investigation of electrothermal effects in high-speed silicon transistors. At high current levels the power dissipation in these devices can lead to heating of both the device itself and the adjacent devices. In advanced transistors these effects are

  20. Testing hadronic interaction models using a highly granular silicon-tungsten calorimeter

    Czech Academy of Sciences Publication Activity Database

    Bilki, B.; Repond, J.; Schlereth, J.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Richard; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav

    2015-01-01

    Roč. 794, Sep (2015), s. 240-254 ISSN 0168-9002 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : electromagnetic silicon tungsten calorimeter * highly granular detectors * hadronic showers * data and simulations Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.200, year: 2015

  1. Fundamental understanding and development of low-cost, high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    ROHATGI,A.; NARASIMHA,S.; MOSCHER,J.; EBONG,A.; KAMRA,S.; KRYGOWSKI,T.; DOSHI,P.; RISTOW,A.; YELUNDUR,V.; RUBY,DOUGLAS S.

    2000-05-01

    The overall objectives of this program are (1) to develop rapid and low-cost processes for manufacturing that can improve yield, throughput, and performance of silicon photovoltaic devices, (2) to design and fabricate high-efficiency solar cells on promising low-cost materials, and (3) to improve the fundamental understanding of advanced photovoltaic devices. Several rapid and potentially low-cost technologies are described in this report that were developed and applied toward the fabrication of high-efficiency silicon solar cells.

  2. Radiation-hard silicon photonics for high energy physics and beyond

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Silicon photonics (SiPh) is currently being investigated as a promising technology for future radiation hard optical links. The possibility of integrating SiPh devices with electronics and/or silicon particle sensors as well as an expected very high resistance against radiation damage make this technology particularly interesting for potential use close to the interaction points in future in high energy physics experiments and other radiation-sensitive applications. The presentation will summarize the outcomes of the research on radiation hard SiPh conducted within the ICE-DIP projected.

  3. High-dimensional quantum key distribution based on multicore fiber using silicon photonic integrated circuits

    DEFF Research Database (Denmark)

    Ding, Yunhong; Bacco, Davide; Dalgaard, Kjeld

    2017-01-01

    is intrinsically limited to 1 bit/photon. Here we propose and experimentally demonstrate, for the first time, a high-dimensional quantum key distribution protocol based on space division multiplexing in multicore fiber using silicon photonic integrated lightwave circuits. We successfully realized three mutually......-dimensional quantum states, and enables breaking the information efficiency limit of traditional quantum key distribution protocols. In addition, the silicon photonic circuits used in our work integrate variable optical attenuators, highly efficient multicore fiber couplers, and Mach-Zehnder interferometers, enabling...

  4. Quantitative analyses of impurity silicon-carbide (SiC) and high-purity-titanium by neutron activation analyses based on k0-standardization method. Development of irradiation silicon technology in productivity using research reactor (Joint research)

    International Nuclear Information System (INIS)

    Motohashi, Jun; Takahashi, Hiroyuki; Magome, Hirokatsu; Sasajima, Fumio; Tokunaga, Okihiro; Kawasaki, Kozo; Onizawa, Koji; Isshiki, Masahiko

    2009-07-01

    JRR-3 and JRR-4 have been providing neutron-transmutation-doped silicon (NTD-Si) by using the silicon NTD process, which is a method to produce a high quality semiconductor. The domestic supply of NTD-Si is insufficient for the demand, and the market of NTD-Si is significantly growing at present. It is very important to increase achieve the production. To fulfill the requirement, we have been investigating a neutron filter, which is made of high-purity-titanium, for uniform doping. Silicon-carbide (SiC) semiconductor doped with NTD technology is considered suitable for high power devices with superior performances to conventional Si-based devices. We are very interested in the SiC as well. This report presents the results obtained after the impurity contents in the high-purity-titanium and SiC were analyzed by neutron activation analyses (NAA) using k 0 -standardization method. There were 6 and 9 impurity elements detected from the high-purity-titanium and SiC, respectively. Among those Sc from the high-purity-titanium and Fe from SiC were comparatively long half life nuclides. From the viewpoint of exposure in handling them, we need to examine the impurity control of materials. (author)

  5. Hierarchical columnar silicon anode structures for high energy density lithium sulfur batteries

    Science.gov (United States)

    Piwko, Markus; Kuntze, Thomas; Winkler, Sebastian; Straach, Steffen; Härtel, Paul; Althues, Holger; Kaskel, Stefan

    2017-05-01

    Silicon is a promising anode material for next generation lithium secondary batteries. To significantly increase the energy density of state of the art batteries with silicon, new concepts have to be developed and electrode structuring will become a key technology. Structuring is essential to reduce the macroscopic and microscopic electrode deformation, caused by the volume change during cycling. We report pulsed laser structuring for the generation of hierarchical columnar silicon films with outstanding high areal capacities up to 7.5 mAh cm-2 and good capacity retention. Unstructured columnar electrodes form a micron-sized block structure during the first cycle to compensate the volume expansion leading to macroscopic electrode deformation. At increased silicon loading, without additional structuring, pronounced distortion and the formation of cracks through the current collector causes cell failure. Pulsed laser ablation instead is demonstrated to avoid macroscopic electrode deformation by initial formation of the block structure. A full cell with lithiated silicon versus a carbon-sulfur cathode is assembled with only 15% overbalanced anode and low electrolyte amount (8 μl mgsulfur-1). While the capacity retention over 50 cycles is identical to a cell with high excess lithium anode, the volumetric energy density could be increased by 30%.

  6. Photo-induced current transient spectroscopy for high-resistivity neutron-transmutation-doped silicon

    International Nuclear Information System (INIS)

    Tokuda, Yutaka; Inoue, Yajiro; Usami, Akira

    1987-01-01

    Defects in high-resistivity neutron-transmutation-doped (NTD) silicon prior to annealing were studied by photo-induced current transient spectroscopy (PICTS). The thermal-neutron fluence was 9.5 x 10 17 cm -2 to give a resistivity of about 30 Ω after annealing, and the fast-neutron fluence was 9.5 x 10 16 cm -2 . Four traps with thermal emission activation energies of 0.15, 0.41. 0.47 and 0.50 eV were observed in NTD silicon. A trap with the thermal emission activation energy of 0.15 eV was considered to correspond to the divacancy. Although the clustered nature of the defects was observed, PICTS measurements suggest that the material state of high-resistivity NTD silicon is still crystalline and not amorphous. (author)

  7. A III-V nanowire channel on silicon for high-performance vertical transistors.

    Science.gov (United States)

    Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi

    2012-08-09

    Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.

  8. High Sensitivity and High Detection Specificity of Gold-Nanoparticle-Grafted Nanostructured Silicon Mass Spectrometry for Glucose Analysis.

    Science.gov (United States)

    Tsao, Chia-Wen; Yang, Zhi-Jie

    2015-10-14

    Desorption/ionization on silicon (DIOS) is a high-performance matrix-free mass spectrometry (MS) analysis method that involves using silicon nanostructures as a matrix for MS desorption/ionization. In this study, gold nanoparticles grafted onto a nanostructured silicon (AuNPs-nSi) surface were demonstrated as a DIOS-MS analysis approach with high sensitivity and high detection specificity for glucose detection. A glucose sample deposited on the AuNPs-nSi surface was directly catalyzed to negatively charged gluconic acid molecules on a single AuNPs-nSi chip for MS analysis. The AuNPs-nSi surface was fabricated using two electroless deposition steps and one electroless etching step. The effects of the electroless fabrication parameters on the glucose detection efficiency were evaluated. Practical application of AuNPs-nSi MS glucose analysis in urine samples was also demonstrated in this study.

  9. High-resolution ion-implanted silicon detectors

    International Nuclear Information System (INIS)

    von Borany, J.; Schmidt, B.

    1985-01-01

    An account is given of the properties of silicon detectors developed at the Central Institute of Nuclear Research of the Academy of Sciences of the German Democratic Republic (Rossendorf) and made by a special planar technology using ion implantation, anodic oxidation, thermal oxidation in an oxygen atmosphere containing HCl, and annealing by pulses of 10--20 msec duration. The resolution for α particles of 5.5 MeV energy was 11.2 keV (active area A 2 ). The detectors were characterized by a low intrinsic noise (< or =5 keV), so that they could be used for spectrometry of low-energy electrons (E/sub e/< or =250 keV). In a certain range of energies (E/sub x/ = 15--60 keV) it was possible to use these detectors for spectrometry of x rays at room temperature. Examples and results of applications of detectors in radiation chemistry (investigations of backscattering of particles and nuclear reaction spectroscopy) are given. The feasibility of annealing of radiation defects in such detectors after irradiation with a large dose of charged particles is considered

  10. The synthesis of a high quality, low cost silicon nitride powder by the carbothermal reduction of silica

    International Nuclear Information System (INIS)

    Cochran, G.A.; Conner, C.L.; Eisman, G.A.; Weimer, A.W.; Carroll, D.F.; Dunmead, S.D.; Hwang, C.J.

    1994-01-01

    The development and emergence of silicon nitride in the marketplace depends on the availability of a high quality, low cost powder which meets or exceeds the requirements for the customer's part application. The Dow Chemical Company, funded by the United States Department of Energy Oak Ridge National Laboratory, is engaged in developing a process which will economically synthesize commercial quantities of such a high quality powder. The Dow Chemical Company's approach is based on the carbothermal reduction of silica and has been shown to produce a sub-micron, equi-axed powder with high alpha content (> 95%), low oxygen (< 2%), and minimal carbon and impurities. This paper will review The Dow Chemical Company program and present preliminary results of the synthesis and powder processing efforts. (orig.)

  11. Recoil implantation of boron into silicon by high energy silicon ions

    Science.gov (United States)

    Shao, L.; Lu, X. M.; Wang, X. M.; Rusakova, I.; Mount, G.; Zhang, L. H.; Liu, J. R.; Chu, Wei-Kan

    2001-07-01

    A recoil implantation technique for shallow junction formation was investigated. After e-gun deposition of a B layer onto Si, 10, 50, or 500 keV Si ion beams were used to introduce surface deposited B atoms into Si by knock-on. It has been shown that recoil implantation with high energy incident ions like 500 keV produces a shallower B profile than lower energy implantation such as 10 keV and 50 keV. This is due to the fact that recoil probability at a given angle is a strong function of the energy of the primary projectile. Boron diffusion was showed to be suppressed in high energy recoil implantation and such suppression became more obvious at higher Si doses. It was suggested that vacancy rich region due to defect imbalance plays the role to suppress B diffusion. Sub-100 nm junction can be formed by this technique with the advantage of high throughput of high energy implanters.

  12. Direct writing of sub-wavelength ripples on silicon using femtosecond laser at high repetition rate

    International Nuclear Information System (INIS)

    Xie, Changxin; Li, Xiaohong; Liu, Kaijun; Zhu, Min; Qiu, Rong; Zhou, Qiang

    2016-01-01

    Graphical abstract: - Highlights: • The NSRs and DSRs are obtained on silicon surface. • With increasing direct writing speed, the NSRs suddenly changes and becomes the DSRs. • We develop a Sipe–Drude interference theory by considering the thermal excitation. - Abstract: The near sub-wavelength and deep sub-wavelength ripples on monocrystalline silicon were formed in air by using linearly polarized and high repetition rate femtosecond laser pulses (f = 76 MHz, λ = 800 nm, τ = 50 fs). The effects of laser pulse energy, direct writing speed and laser polarization on silicon surface morphology are studied. When the laser pulse energy is 2 nJ/pulse and the direct writing speed varies from 10 to 25 mm/s, the near sub-wavelength ripples (NSRs) with orientation perpendicular to the laser polarization are generated. While the direct writing speed reaches 30 mm/s, the direction of the obtained deep sub-wavelength ripples (DSRs) suddenly changes and becomes parallel to the laser polarization, rarely reported so far for femtosecond laser irradiation of silicon. Meanwhile, we extend the Sipe–Drude interference theory by considering the thermal excitation, and numerically calculate the efficacy factor for silicon irradiated by femtosecond laser pulses. The revised Sipe–Drude interference theoretical results show good agreement with the periods and orientations of sub-wavelength ripples.

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

    International Nuclear Information System (INIS)

    Hildering, Sven; Engel, Ulf; Merklein, Marion

    2011-01-01

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

  14. Silicene Flowers: A Dual Stabilized Silicon Building Block for High-Performance Lithium Battery Anodes.

    Science.gov (United States)

    Zhang, Xinghao; Qiu, Xiongying; Kong, Debin; Zhou, Lu; Li, Zihao; Li, Xianglong; Zhi, Linjie

    2017-07-25

    Nanostructuring is a transformative way to improve the structure stability of high capacity silicon for lithium batteries. Yet, the interface instability issue remains and even propagates in the existing nanostructured silicon building blocks. Here we demonstrate an intrinsically dual stabilized silicon building block, namely silicene flowers, to simultaneously address the structure and interface stability issues. These original Si building blocks as lithium battery anodes exhibit extraordinary combined performance including high gravimetric capacity (2000 mAh g -1 at 800 mA g -1 ), high volumetric capacity (1799 mAh cm -3 ), remarkable rate capability (950 mAh g -1 at 8 A g -1 ), and excellent cycling stability (1100 mA h g -1 at 2000 mA g -1 over 600 cycles). Paired with a conventional cathode, the fabricated full cells deliver extraordinarily high specific energy and energy density (543 Wh kg ca -1 and 1257 Wh L ca -1 , respectively) based on the cathode and anode, which are 152% and 239% of their commercial counterparts using graphite anodes. Coupled with a simple, cost-effective, scalable synthesis approach, this silicon building block offers a horizon for the development of high-performance batteries.

  15. High efficiency high rate microcrystalline silicon thin-film solar cells deposited at plasma excitation frequencies larger than 100 MHz

    Czech Academy of Sciences Publication Activity Database

    Strobel, C.; Leszczynska, B.; Merkel, U.; Kuske, J.; Fischer, D.D.; Albert, M.; Holovský, Jakub; Michard, S.

    2015-01-01

    Roč. 143, Dec (2015), 347-353 ISSN 0927-0248 R&D Projects: GA MŠk 7E12029 EU Projects: European Commission(XE) 283501 - Fast Track Institutional support: RVO:68378271 Keywords : VHF * PECVD * microcrystalline silicon * solar cell * high rate * high efficiency Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.732, year: 2015

  16. Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics.

    Science.gov (United States)

    Ghoneim, Mohamed Tarek; Hussain, Muhammad Mustafa

    2017-04-01

    A highly manufacturable deep reactive ion etching based process involving a hybrid soft/hard mask process technology shows high aspect ratio complex geometry Lego-like silicon electronics formation enabling free-form (physically flexible, stretchable, and reconfigurable) electronic systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics

    KAUST Repository

    Ghoneim, Mohamed T.

    2017-02-01

    A highly manufacturable deep reactive ion etching based process involving a hybrid soft/hard mask process technology shows high aspect ratio complex geometry Lego-like silicon electronics formation enabling free-form (physically flexible, stretchable, and reconfigurable) electronic systems.

  18. Time-Efficient High-Resolution Large-Area Nano-Patterning of Silicon Dioxide

    DEFF Research Database (Denmark)

    Lin, Li; Ou, Yiyu; Aagesen, Martin

    2017-01-01

    A nano-patterning approach on silicon dioxide (SiO2) material, which could be used for the selective growth of III-V nanowires in photovoltaic applications, is demonstrated. In this process, a silicon (Si) stamp with nanopillar structures was first fabricated using electron-beam lithography (EBL....... In addition, high time efficiency can be realized by one-spot electron-beam exposure in the EBL process combined with NIL for mass production. Furthermore, the one-spot exposure enables the scalability of the nanostructures for different application requirements by tuning only the exposure dose. The size...

  19. High-Q silicon-on-insulator slot photonic crystal cavity infiltrated by a liquid

    International Nuclear Information System (INIS)

    Caër, Charles; Le Roux, Xavier; Cassan, Eric

    2013-01-01

    We report the experimental realization of a high-Q slot photonic crystal cavity in Silicon-On-Insulator (SOI) configuration infiltrated by a liquid. Loaded Q-factor of 23 000 is measured at telecom wavelength. The intrinsic quality factor inferred from the transmission spectrum is higher than 200 000, which represents a record value for slot photonic crystal cavities on SOI, whereas the maximum of intensity of the cavity is roughly equal to 20% of the light transmitted in the waveguide. This result makes filled slot photonic crystal cavities very promising for silicon-based light emission and ultrafast nonlinear optics

  20. Extraction-spectrophotometric method for silicon determination in high-purity substances. 1. Silicon determination in tellurium

    Energy Technology Data Exchange (ETDEWEB)

    Shaburova, V P; Yudelevich, I G [AN SSSR, Novosibirsk (USSR). Inst. Neorganicheskoj Khimii

    1989-01-01

    The extraction-spectrophotometric method for silicon determination in tellurium based on extraction isolation of the base by tributyl phosphate from hydrochloride solutions and with addition of HNO/sub 3/ and spectrophotometric silicon determination using malachite green is developed. The method permits to determine 2x10/sup -1/-3x10/sup -4/ % Si.

  1. Challenges and solutions for high-volume testing of silicon photonics

    Science.gov (United States)

    Polster, Robert; Dai, Liang Yuan; Oikonomou, Michail; Cheng, Qixiang; Rumley, Sebastien; Bergman, Keren

    2018-02-01

    The first generation of silicon photonic products is now commercially available. While silicon photonics possesses key economic advantages over classical photonic platforms, it has yet to become a commercial success because these advantages can be fully realized only when high-volume testing of silicon photonic devices is made possible. We discuss the costs, challenges, and solutions of photonic chip testing as reported in the recent research literature. We define and propose three underlying paradigms that should be considered when creating photonic test structures: Design for Fast Coupling, Design for Minimal Taps, and Design for Parallel Testing. We underline that a coherent test methodology must be established prior to the design of test structures, and demonstrate how an optimized methodology dramatically reduces the burden when designing for test, by reducing the needed complexity of test structures.

  2. HOLE-BLOCKING LAYERS FOR SILICON/ORGANIC HETEROJUNCTIONS: A NEW CLASS OF HIGH-EFFICIENCY LOW-COST PV

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, James [Princeton Univ., NJ (United States)

    2017-12-04

    This project is the first investigation of the use of thin titanium dioxide layers on silicon as a hole-blocking / electron-transparent selective contact to silicon. The work was motivated by the goal of a high-efficiency low-cost silicon-based solar cells that could be processed entirely at low temperature (300 Degree Celsius) or less, without requiring plasma-processing.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-09-01

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

  4. Radiation damage in silicon exposed to high-energy protons

    International Nuclear Information System (INIS)

    Davies, Gordon; Hayama, Shusaku; Murin, Leonid; Krause-Rehberg, Reinhard; Bondarenko, Vladimir; Sengupta, Asmita; Davia, Cinzia; Karpenko, Anna

    2006-01-01

    Photoluminescence, infrared absorption, positron annihilation, and deep-level transient spectroscopy (DLTS) have been used to investigate the radiation damage produced by 24 GeV/c protons in crystalline silicon. The irradiation doses and the concentrations of carbon and oxygen in the samples have been chosen to monitor the mobility of the damage products. Single vacancies (and self-interstitials) are introduced at the rate of ∼1 cm -1 , and divacancies at 0.5 cm -1 . Stable di-interstitials are formed when two self-interstitials are displaced in one damage event, and they are mobile at room temperature. In the initial stages of annealing the evolution of the point defects can be understood mainly in terms of trapping at the impurities. However, the positron signal shows that about two orders of magnitude more vacancies are produced by the protons than are detected in the point defects. Damage clusters exist, and are largely removed by annealing at 700 to 800 K, when there is an associated loss of broad band emission between 850 and 1000 meV. The well-known W center is generated by restructuring within clusters, with a range of activation energies of about 1.3 to 1.6 eV, reflecting the disordered nature of the clusters. Comparison of the formation of the X centers in oxygenated and oxygen-lean samples suggests that the J defect may be interstitial related rather than vacancy related. To a large extent, the damage and annealing behavior may be factorized into point defects (monitored by sharp-line optical spectra and DLTS) and cluster defects (monitored by positron annihilation and broadband luminescence). Taking this view to the limit, the generation rates for the point defects are as predicted by simply taking the damage generated by the Coulomb interaction of the protons and Si nuclei

  5. Performance of a silicon microstrip detector in a high radiation environment

    International Nuclear Information System (INIS)

    Mishra, C.S.; Brown, C.N.; Kapustinsky, J.; Leitch, M.J.; McGaughey, P.L.; Peng, J.C.; Sailor, W.; Holzscheiter, K.; Sadler, M.

    1990-01-01

    This paper reports on the performance of a silicon microstrip detector that has been studied in a high rate environment using electron, pion, and proton beams. The pulse height, time response, and leakage current have been studied as a function of particle fluence up to a total integrated flus of about 4 x 10 14 protons/cm 2

  6. 77 GHz MEMS antennas on high-resistivity silicon for linear and circular polarization

    KAUST Repository

    Sallam, M. O.

    2011-07-01

    Two new MEMS antennas operating at 77 GHz are presented in this paper. The first antenna is linearly polarized. It possesses a vertical silicon wall that carries a dipole on top of it. The wall is located on top of silicon substrate covered with a ground plane. The other side of the substrate carries a microstrip feeding network in the form of U-turn that causes 180 phase shift. This phase-shifter feeds the arms of the dipole antenna via two vertical Through-Silicon Vias (TSVs) that go through the entire wafer. The second antenna is circularly polarized and formed using two linearly polarized antennas spatially rotated with respect to each other by 90 and excited with 90 phase shift. Both antennas are fabricated using novel process flow on a single high-resistivity silicon wafer via bulk micromachining. Only three processing steps are required to fabricate these antennas. The proposed antennas have appealing characteristics, such as high polarization purity, high gain, and high radiation efficiency. © 2011 IEEE.

  7. Ultra-high efficiency, fast graphene micro-heater on silicon

    DEFF Research Database (Denmark)

    Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn

    2017-01-01

    We demonstrate an ultra-high efficiency and fast graphene microheater on silicon photonic crystal waveguide. By taking advantage of slow-light effect, a tuning efficiency of 1.07 nm/mW and power consumption per free spectral range of 3.99 mW. A fast rise and decay times (10% to 90%) of only 750 ns...

  8. Very high frequency plasma deposited amorphous/nanocrystalline silicon tandem solar cells on flexible substrates

    NARCIS (Netherlands)

    Liu, Y.|info:eu-repo/dai/nl/304831743

    2010-01-01

    The work in this thesis is to develop high quality intrinsic layers (especially nc-Si:H) for micromorph silicon tandem solar cells/modules on plastic substrates following the substrate transfer method or knows as the Helianthos procedure. Two objectives are covered in this thesis: (1) preliminary

  9. Thin-Film layers with Interfaces that reduce RF Losses on High-Resistivity Silicon Substrates

    NARCIS (Netherlands)

    Evseev, S. B.; Milosavljevic, S.; Nanver, L. K.

    2017-01-01

    Radio-Frequency (RF) losses on High-Resistivity Silicon (HRS) substrates were studied for several different surface passivation layers comprising thin-films of SiC, SiN and SiO2 In many combinations, losses from conductive surface channels were reduced and increasing the number of interfaces between

  10. Compact high-efficiency vortex beam emitter based on a silicon photonics micro-ring

    DEFF Research Database (Denmark)

    Li, Shimao; Ding, Yunhong; Guan, Xiaowei

    2018-01-01

    Photonic integrated devices that emit vortex beam carrying orbital angular momentum are becoming key components for multiple applications. Here we propose and demonstrate a high-efficiency vortex beam emitter based on a silicon micro-ring resonator integrated with a metal mirror. Such a compact...

  11. Carbon−Silicon Core−Shell Nanowires as High Capacity Electrode for Lithium Ion Batteries

    KAUST Repository

    Cui, Li-Feng

    2009-09-09

    We introduce a novel design of carbon-silicon core-shell nanowires for high power and long life lithium battery electrodes. Amorphous silicon was coated onto carbon nanofibers to form a core-shell structure and the resulted core-shell nanowires showed great performance as anode material. Since carbon has a much smaller capacity compared to silicon, the carbon core experiences less structural stress or damage during lithium cycling and can function as a mechanical support and an efficient electron conducting pathway. These nanowires have a high charge storage capacity of ∼2000 mAh/g and good cycling life. They also have a high Coulmbic efficiency of 90% for the first cycle and 98-99.6% for the following cycles. A full cell composed of LiCoO2 cathode and carbon-silicon core-shell nanowire anode is also demonstrated. Significantly, using these core-shell nanowires we have obtained high mass loading and an area capacity of ∼4 mAh/cm2, which is comparable to commercial battery values. © 2009 American Chemical Society.

  12. Guidelines for etching silicon MEMS structures using fluorine high-density plasmas at cryogenic temperatures

    NARCIS (Netherlands)

    de Boer, Meint J.; Gardeniers, Johannes G.E.; Jansen, Henricus V.; Gilde, M.J.; Roelofs, Gerard; Sasserath, Jay N.; Elwenspoek, Michael Curt

    This paper presents guidelines for the deep reactive ion etching (DRIE) of silicon MEMS structures, employing SF6/O2-based high-density plasmas at cryogenic temperatures. Procedures of how to tune the equipment for optimal results with respect to etch rate and profile control are described. Profile

  13. Signal generation in highly irradiated silicon microstrip detectors for the ATLAS experiment

    International Nuclear Information System (INIS)

    Ruggiero, Gennaro

    2003-01-01

    Silicon detectors are the most diffused tracking devices in High Energy Physics (HEP). The reason of such success can be found in the characteristics of the material together with the existing advanced technology for the fabrication of these devices. Nevertheless in many modem HEP experiments the observation of vary rare events require data taking at high luminosity with a consequent extremely intense hadron radiation field that damages the silicon and degrades the performance of these devices. In this thesis work a detailed study of the signal generation in microstrip detectors has been produced with a special care for the ATLAS semiconductor tracker geometry. This has required a development of an appropriate setup to perform measurements with Transient Current/ Charge Technique. This has allowed studying the evolution of the signal in several microstrips detector samples irradiated at fluences covering the range expected in the ATLAS Semiconductor Tracker. For a better understanding of these measurements a powerful software package that simulates the signal generation in these devices has been developed. Moreover in this thesis it has been also shown that the degradation due to radiation in silicon detectors can be strongly reduced if the data taking is done with detectors operated at 130 K. This makes low temperature operation that benefits of the recovery of the charge collection efficiency in highly irradiated silicon detectors (also known as Lazarus effect) an optimal option for future high luminosity experiments. (author)

  14. In-line high-rate evaporation of aluminum for the metallization of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mader, Christoph Paul

    2012-07-11

    This work focuses on the in-line high-rate evaporation of aluminum for contacting rear sides of silicon solar cells. The substrate temperature during the deposition process, the wafer bow after deposition, and the electrical properties of evaporated contacts are investigated. Furthermore, this work demonstrates for the first time the formation of aluminum-doped silicon regions by the in-line high-rate evaporation of aluminum without any further temperature treatment. The temperature of silicon wafers during in-line high-rate evaporation of aluminum is investigated in this work. The temperatures are found to depend on the wafer thickness W, the aluminum layer thickness d, and on the wafer emissivity {epsilon}. Two-dimensional finite-element simulations reproduce the measured peak temperatures with an accuracy of 97%. This work also investigates the wafer bow after in-line high-rate evaporation and shows that the elastic theory overestimates the wafer bow of planar Si wafers. The lower bow is explained with plastic deformation in the Al layer. Due to the plastic deformation only the first 79 K in temperature decrease result in a bow formation. Furthermore the electrical properties of evaporated point contacts are examined in this work. Parameterizations for the measured saturation currents of contacted p-type Si wafers and of contacted boron-diffused p{sup +}-type layers are presented. The contact resistivity of the deposited Al layers to silicon for various deposition processes and silicon surface concentrations are presented and the activation energy of the contact formation is determined. The measured saturation current densities and contact resistivities of the evaporated contacts are used in one-dimensional numerical Simulations and the impact on energy conversion efficiency of replacing a screen-printed rear side by an evaporated rear side is presented. For the first time the formation of aluminum-doped p{sup +}-type (Al-p{sup +}) silicon regions by the in

  15. Organosilica hybrid nanomaterials with a high organic content: syntheses and applications of silsesquioxanes

    KAUST Repository

    Croissant, Jonas G.

    2016-11-07

    Organic-inorganic hybrid materials garner properties from their organic and inorganic matrices as well as synergistic features, and therefore have recently attracted much attention at the nanoscale. Non-porous organosilica hybrid nanomaterials with a high organic content such as silsesquioxanes (R-SiO, with R organic groups) and bridged silsesquioxanes (OSi-R-SiO) are especially attractive hybrids since they provide 20 to 80 weight percent of organic functional groups in addition to the known chemistry and stability of silica. In the organosilica family, silsesquioxanes (R-SiO) stand between silicas (SiO) and silicones (RSiO), and are variously called organosilicas, ormosil (organically-modified silica), polysilsesquioxanes and silica hybrids. Herein, we comprehensively review non-porous silsesquioxane and bridged silsesquioxane nanomaterials and their applications in nanomedicine, electro-optics, and catalysis.

  16. Single-crystal silicon trench etching for fabrication of highly integrated circuits

    Science.gov (United States)

    Engelhardt, Manfred

    1991-03-01

    The development of single crystal silicon trench etching for fabrication of memory cells in 4 16 and 64Mbit DRAMs is reviewed in this paper. A variety of both etch tools and process gases used for the process development is discussed since both equipment and etch chemistry had to be improved and changed respectively to meet the increasing requirements for high fidelity pattern transfer with increasing degree of integration. In additon to DRAM cell structures etch results for deep trench isolation in advanced bipolar ICs and ASICs are presented for these applications grooves were etched into silicon through a highly doped buried layer and at the borderline of adjacent p- and n-well areas respectively. Shallow trench etching of large and small exposed areas with identical etch rates is presented as an approach to replace standard LOCOS isolation by an advanced isolation technique. The etch profiles were investigated with SEM TEM and AES to get information on contathination and damage levels and on the mechanism leading to anisotropy in the dry etch process. Thermal wave measurements were performed on processed single crystal silicon substrates for a fast evaluation of the process with respect to plasma-induced substrate degradation. This useful technique allows an optimization ofthe etch process regarding high electrical performance of the fully processed memory chip. The benefits of the use of magnetic fields for the development of innovative single crystal silicon dry

  17. Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

    KAUST Repository

    Bahabry, Rabab R.

    2018-01-02

    Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

  18. Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

    KAUST Repository

    Bahabry, Rabab R.; Kutbee, Arwa T.; Khan, Sherjeel M.; Sepulveda, Adrian C.; Wicaksono, Irmandy; Nour, Maha A.; Wehbe, Nimer; Almislem, Amani Saleh Saad; Ghoneim, Mohamed T.; Sevilla, Galo T.; Syed, Ahad; Shaikh, Sohail F.; Hussain, Muhammad Mustafa

    2018-01-01

    Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

  19. Changes in myopia with low-Dk hydrogel and high-Dk silicone hydrogel extended wear.

    Science.gov (United States)

    Jalbert, Isabelle; Stretton, Serina; Naduvilath, Thomas; Holden, Brien; Keay, Lisa; Sweeney, Deborah

    2004-08-01

    This study compared changes in myopia between wearers of high-oxygen permeability (Dk) silicone hydrogel lenses and low-Dk hydrogel lenses after 1 year of extended wear (EW). Ninety-two adult subjects were randomly assigned to a lens type. Subjective refraction and autokeratometry were performed at baseline and at 6 and 12 months. After 6 months of EW, myopia (spherical equivalent) regressed by 0.18 +/- 0.33 D (p Dk silicone hydrogel group and progressed by -0.23 +/- 0.36 D (p Dk hydrogel group. There were no further changes after 12 months. Previous lens wear history, baseline refractive error, and age and gender did not have an impact on the change in myopia, and only 35% of the variation could be accounted for by changes in corneal curvature and lens type. Soft contact lens type significantly affects the direction of change in myopia during EW. We hypothesize that these changes are driven by pressure-related redistribution of corneal tissue in high-Dk silicone hydrogel lens wearers and by hypoxia-associated corneal thinning in low-Dk hydrogel wearers. More long-term studies are required to confirm whether the effects of high-Dk silicone hydrogel lens wear on myopia are permanent.

  20. High-performance macroporous bulk silicon anodes synthesized by template-free chemical etching

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Byoung Man; Lee, Jung-In; Kim, Hyunjung; Cho, Jaephil; Park, Soojin [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of)

    2012-07-15

    Three-dimensional porous silicon particles can be produced via the combination of a galvanic displacement reaction and a metal-assisted chemical etching process. This simple synthetic route can be applied to make high-performance anode materials, including high specific capacity, stable cycling retention, and high rate capability, in lithium-ion batteries. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Technological development for super-high efficiency solar cells. Technological development of solar-high efficiency singlecrystalline silicon solar cells (high quality singlecrystalline silicon substrates); Chokokoritsu taiyo denchi no gijutsu kaihatsu. Chokokoritsu tankessho silicon taiyo denchi no gijutsu kaihatsu (kohinshitsu tankessho silicon kiban no gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    This paper reports the study results on technological development for high quality efficiency singlecrystalline silicon substrates in fiscal 1994. (1) On electromagnetic casting/once FZ bath method, a Si single crystal of 600mm long was successfully obtained by improvement of power source frequency and furnace parts. High carbon content resulted in no single crystal including solids. In undoped electromagnetic casting ingots, resistivities over 1500ohm-cm were obtained because of effective preventive measures from contaminants. (2) On electromagnetic melting CZ method, since vibration and temperature control of melt surface by magnetic shield was insufficient for stable pulling of single crystals, its practical use was hopeless. (3) On electron beam melting CZ method, a Si single crystal of 25mm in diameter was obtained by preventive measures from evaporation of Si and influence of deposits, and improved uniform deposition distribution in a furnace. The oscillation circuit constant of power source, and water-cooling copper crucible structure were also analyzed for the optimum design of electromagnetic melting furnaces. 3 figs., 1 tab.

  2. High-field Overhauser dynamic nuclear polarization in silicon below the metal-insulator transition.

    Science.gov (United States)

    Dementyev, Anatoly E; Cory, David G; Ramanathan, Chandrasekhar

    2011-04-21

    Single crystal silicon is an excellent system to explore dynamic nuclear polarization (DNP), as it exhibits a continuum of properties from metallic to insulating as a function of doping concentration and temperature. At low doping concentrations DNP has been observed to occur via the solid effect, while at very high-doping concentrations an Overhauser mechanism is responsible. Here we report the hyperpolarization of (29)Si in n-doped silicon crystals, with doping concentrations in the range of (1-3) × 10(17) cm(-3). In this regime exchange interactions between donors become extremely important. The sign of the enhancement in our experiments and its frequency dependence suggest that the (29)Si spins are directly polarized by donor electrons via an Overhauser mechanism within exchange-coupled donor clusters. The exchange interaction between donors only needs to be larger than the silicon hyperfine interaction (typically much smaller than the donor hyperfine coupling) to enable this Overhauser mechanism. Nuclear polarization enhancement is observed for a range of donor clusters in which the exchange energy is comparable to the donor hyperfine interaction. The DNP dynamics are characterized by a single exponential time constant that depends on the microwave power, indicating that the Overhauser mechanism is a rate-limiting step. Since only about 2% of the silicon nuclei are located within 1 Bohr radius of the donor electron, nuclear spin diffusion is important in transferring the polarization to all the spins. However, the spin-diffusion time is much shorter than the Overhauser time due to the relatively weak silicon hyperfine coupling strength. In a 2.35 T magnetic field at 1.1 K, we observed a DNP enhancement of 244 ± 84 resulting in a silicon polarization of 10.4 ± 3.4% following 2 h of microwave irradiation.

  3. Microstructure and wear behavior of austempered high carbon high silicon steel

    Directory of Open Access Journals (Sweden)

    Acharya Palaksha

    2018-01-01

    Full Text Available In the present investigation, the influence of austempering temperature and time on the microstructure and dry sliding wear behavior of high silicon steel was studied. The test specimens were initially austenitised at 900°C for 30 minutes, thereafter austempered at various temperatures 280°C, 360°C and 400°C, for varying duration from 30 to 120 minutes. These samples after austempering heat treatment were subsequently air cooled to room temperature, to generate typical ausferritic microstructures and then correlated with the wear property. The test outcomes demonstrate the slight increase in specific wear rate with increase in both austempering temperature and time. Specific wear rate was found to be minimum at an austempering temperature of 280°C, that exhibits lower bainite microstructure with high hardness, on the other hand specific wear rate was found to be slightly high at increased austempering temperatures at 360°C and 400°C, due to the upper bainite structure that offered lower hardness to the matrix. The sample austempered at 280°C for 30 minutes offered superior wear resistance when compared to other austempering conditions, mainly due to the presence of fine acicular bainitic ferrite along with stabilized retained austenite and also some martensite in the microstructure.

  4. Human islet viability and function is maintained during high density shipment in silicone rubber membrane vessels

    Science.gov (United States)

    Kitzmann, Jennifer P; Pepper, Andrew R; Lopez, Boris G; Pawlick, Rena; Kin, Tatsuya; O’Gorman, Doug; Mueller, Kathryn R; Gruessner, Angelika C; Avgoustiniatos, Efstathios S; Karatzas, Theodore; Szot, Greg L; Posselt, Andrew M; Stock, Peter G; Wilson, John R; Shapiro, AM; Papas, Klearchos K

    2014-01-01

    The shipment of human islets from processing centers to distant laboratories is beneficial for both research and clinical applications. The maintenance of islet viability and function in transit is critically important. Gas-permeable silicone rubber membrane (SRM) vessels reduce the risk of hypoxia-induced death or dysfunction during high-density islet culture or shipment. SRM vessels may offer additional advantages: they are cost-effective (fewer flasks, less labor needed), safer (lower contamination risk), and simpler (culture vessel can also be used for shipment). Human islets(IE) were isolated from two manufacturing centers and shipped in 10cm2 surface area SRM vessels in temperature and pressure controlled containers to a distant center following at least two days of culture (n = 6). Three conditions were examined: low density (LD), high density (HD), and a micro centrifuge tube negative control (NC). LD was designed to mimic the standard culture density for human islet preparations (200 IE/cm2), while HD was designed to have a 20-fold higher tissue density, which would enable the culture of an entire human isolation in 1–3 vessels. Upon receipt, islets were assessed for viability, measured by oxygen consumption rate normalized to DNA content (OCR/DNA), and quantity, measured by DNA, and, when possible, potency and function with dynamic glucose-stimulated insulin secretion (GSIS) measurements and transplants in immunodeficient B6 rag mice. Post-shipment OCR/DNA was not reduced in HD versus LD, and was substantially reduced in the NC condition. HD islets exhibited normal function post-shipment. Based on the data we conclude that entire islet isolations (up to 400,000 IE) may be shipped using a single, larger SRM vessel with no negative effect on viability and ex vivo and in vivo function. PMID:25131090

  5. Development of Thin Film Amorphous Silicon Tandem Junction Based Photocathodes Providing High Open-Circuit Voltages for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    F. Urbain

    2014-01-01

    Full Text Available Hydrogenated amorphous silicon thin film tandem solar cells (a-Si:H/a-Si:H have been developed with focus on high open-circuit voltages for the direct application as photocathodes in photoelectrochemical water splitting devices. By temperature variation during deposition of the intrinsic a-Si:H absorber layers the band gap energy of a-Si:H absorber layers, correlating with the hydrogen content of the material, can be adjusted and combined in a way that a-Si:H/a-Si:H tandem solar cells provide open-circuit voltages up to 1.87 V. The applicability of the tandem solar cells as photocathodes was investigated in a photoelectrochemical cell (PEC measurement set-up. With platinum as a catalyst, the a-Si:H/a-Si:H based photocathodes exhibit a high photocurrent onset potential of 1.76 V versus the reversible hydrogen electrode (RHE and a photocurrent of 5.3 mA/cm2 at 0 V versus RHE (under halogen lamp illumination. Our results provide evidence that a direct application of thin film silicon based photocathodes fulfills the main thermodynamic requirements to generate hydrogen. Furthermore, the presented approach may provide an efficient and low-cost route to solar hydrogen production.

  6. Silicon coating treatment to improve high temperature corrosion resistance of 9%Cr steels

    International Nuclear Information System (INIS)

    Hill, M.P.

    1989-01-01

    A silicon coating process is described which confers good protection on 9%Cr steels and alloys in CO 2 based atmospheres at high temperatures and pressures. The coatings are formed by decomposition of silane at temperatures above 720 K. Protective layers are typically up to 1 μm thick. The optimum coating conditions are discussed. The chemical state of the coatings has been investigated by X-ray photoelectron spectroscopy and has demonstrated the importance of avoiding silicon oxide formation during processing. Corrosion testing has been carried out for extended periods, up to 20 000 h, at temperatures between 753 and 853 K, in a simulated advanced gas cooled reactor gas at 4 MPa pressure. Benefit factors of up to 60 times have been measured for 9%Cr steels. Even higher values have been measured for 9Cr-Fe binary alloy on which a 1 μm coating was sufficient to eliminate significant oxidation over 19 000 h except at the specimen edges. The mechanism of protection is discussed. It is suggested that a silicon surface coating for protecting steels from high temperature corrosion has some advantages over adding silicon to the bulk metal. (author)

  7. Industrially feasible, dopant-free, carrier-selective contacts for high-efficiency silicon solar cells

    KAUST Repository

    Yang, Xinbo

    2017-05-31

    Dopant-free, carrier-selective contacts (CSCs) on high efficiency silicon solar cells combine ease of deposition with potential optical benefits. Electron-selective titanium dioxide (TiO) contacts, one of the most promising dopant-free CSC technologies, have been successfully implemented into silicon solar cells with an efficiency over 21%. Here, we report further progress of TiO contacts for silicon solar cells and present an assessment of their industrial feasibility. With improved TiO contact quality and cell processing, a remarkable efficiency of 22.1% has been achieved using an n-type silicon solar cell featuring a full-area TiO contact. Next, we demonstrate the compatibility of TiO contacts with an industrial contact-firing process, its low performance sensitivity to the wafer resistivity, its applicability to ultrathin substrates as well as its long-term stability. Our findings underscore the great appeal of TiO contacts for industrial implementation with their combination of high efficiency with robust fabrication at low cost.

  8. High Surface Area of Porous Silicon Drives Desorption of Intact Molecules

    Science.gov (United States)

    Northen, Trent R.; Woo, Hin-Koon; Northen, Michael T.; Nordström, Anders; Uritboonthail, Winnie; Turner, Kimberly L.; Siuzdak, Gary

    2007-01-01

    The surface structure of porous silicon used in desorption/ionization on porous silicon (DIOS) mass analysis is known to play a primary role in the desorption/ionization (D/I) process. In this study, mass spectrometry and scanning electron microscopy (SEM) are used to examine the correlation between intact ion generation with surface ablation, and surface morphology. The DIOS process is found to be highly laser energy dependent and correlates directly with the appearance of surface ions (Sin+ and OSiH+). A threshold laser energy for DIOS is observed (10 mJ/cm2), which supports that DIOS is driven by surface restructuring and is not a strictly thermal process. In addition, three DIOS regimes are observed which correspond to surface restructuring and melting. These results suggest that higher surface area silicon substrates may enhance DIOS performance. A recent example which fits into this mechanism is silicon nanowires surface which have a high surface energy and concomitantly requires lower laser energy for analyte desorpton. PMID:17881245

  9. Shedding Light on Filovirus Infection with High-Content Imaging

    Directory of Open Access Journals (Sweden)

    Rekha G. Panchal

    2012-08-01

    Full Text Available Microscopy has been instrumental in the discovery and characterization of microorganisms. Major advances in high-throughput fluorescence microscopy and automated, high-content image analysis tools are paving the way to the systematic and quantitative study of the molecular properties of cellular systems, both at the population and at the single-cell level. High-Content Imaging (HCI has been used to characterize host-virus interactions in genome-wide reverse genetic screens and to identify novel cellular factors implicated in the binding, entry, replication and egress of several pathogenic viruses. Here we present an overview of the most significant applications of HCI in the context of the cell biology of filovirus infection. HCI assays have been recently implemented to quantitatively study filoviruses in cell culture, employing either infectious viruses in a BSL-4 environment or surrogate genetic systems in a BSL-2 environment. These assays are becoming instrumental for small molecule and siRNA screens aimed at the discovery of both cellular therapeutic targets and of compounds with anti-viral properties. We discuss the current practical constraints limiting the implementation of high-throughput biology in a BSL-4 environment, and propose possible solutions to safely perform high-content, high-throughput filovirus infection assays. Finally, we discuss possible novel applications of HCI in the context of filovirus research with particular emphasis on the identification of possible cellular biomarkers of virus infection.

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

    Science.gov (United States)

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

    2018-04-01

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

  11. High performance multilayered nano-crystalline silicon/silicon-oxide light-emitting diodes on glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Darbari, S; Shahmohammadi, M; Mortazavi, M; Mohajerzadeh, S [Thin Film and Nano-Electronic Laboratory, School of ECE, University of Tehran, Tehran (Iran, Islamic Republic of); Abdi, Y [Nano-Physics Research Laboratory, Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Robertson, M; Morrison, T, E-mail: mohajer@ut.ac.ir [Department of Physics, Acadia University, Wolfville, NS (Canada)

    2011-09-16

    A low-temperature hydrogenation-assisted sequential deposition and crystallization technique is reported for the preparation of nano-scale silicon quantum dots suitable for light-emitting applications. Radio-frequency plasma-enhanced deposition was used to realize multiple layers of nano-crystalline silicon while reactive ion etching was employed to create nano-scale features. The physical characteristics of the films prepared using different plasma conditions were investigated using scanning electron microscopy, transmission electron microscopy, room temperature photoluminescence and infrared spectroscopy. The formation of multilayered structures improved the photon-emission properties as observed by photoluminescence and a thin layer of silicon oxy-nitride was then used for electrical isolation between adjacent silicon layers. The preparation of light-emitting diodes directly on glass substrates has been demonstrated and the electroluminescence spectrum has been measured.

  12. Design and development of fluidized bed reactor system for production of trichlorosilane as a precursor for high purity silicon

    International Nuclear Information System (INIS)

    Kumar, Rajesh; Mohan, Sadhana; Bhanja, K.; Nayak, S.; Bhattacharya, S.K.

    2009-01-01

    Trichlorosilane is widely used as precursor material for production of high purity silicon. It is mainly produced by reaction of metallurgical grade silicon with anhydrous HCl gas in a fluidized bed reactor. To develop this process on commercial scale a pilot size fluidized bed reactor system was designed and developed and successfully operated. This paper discusses the critical issues related to these activities. (author)

  13. Very high-cycle fatigue failure in micron-scale polycrystalline silicon films : Effects of environment and surface oxide thickness

    NARCIS (Netherlands)

    Alsem, D. H.; Boyce, B. L.; Stach, E. A.; De Hosson, J. Th. M.; Ritchie, R. O.

    2007-01-01

    Fatigue failure in micron-scale polycrystalline silicon structural films, a phenomenon that is not observed in bulk silicon, can severely impact the durability and reliability of microelectromechanical system devices. Despite several studies on the very high-cycle fatigue behavior of these films (up

  14. Crystalline-Amorphous Core−Shell Silicon Nanowires for High Capacity and High Current Battery Electrodes

    KAUST Repository

    Cui, Li-Feng; Ruffo, Riccardo; Chan, Candace K.; Peng, Hailin; Cui, Yi

    2009-01-01

    fading, has limited its applications. Designing nanoscale hierarchical structures is a novel approach to address the issues associated with the large volume changes. In this letter, we introduce a core-shell design of silicon nanowires for highpower

  15. Research, development and pilot production of high output thin silicon solar cells

    Science.gov (United States)

    Iles, P. A.

    1976-01-01

    Work was performed to define and apply processes which could lead to high output from thin (2-8 mils) silicon solar cells. The overall problems are outlined, and two satisfactory process sequences were developed. These sequences led to good output cells in the thickness range to just below 4 mils; although the initial contract scope was reduced, one of these sequences proved capable of operating beyond a pilot line level, to yield good quality 4-6 mil cells of high output.

  16. High-resolution patterning of graphene by screen printing with a silicon stencil for highly flexible printed electronics.

    Science.gov (United States)

    Hyun, Woo Jin; Secor, Ethan B; Hersam, Mark C; Frisbie, C Daniel; Francis, Lorraine F

    2015-01-07

    High-resolution screen printing of pristine graphene is introduced for the rapid fabrication of conductive lines on flexible substrates. Well-defined silicon stencils and viscosity-controlled inks facilitate the preparation of high-quality graphene patterns as narrow as 40 μm. This strategy provides an efficient method to produce highly flexible graphene electrodes for printed electronics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Enabling electrolyte compositions for columnar silicon anodes in high energy secondary batteries

    Science.gov (United States)

    Piwko, Markus; Thieme, Sören; Weller, Christine; Althues, Holger; Kaskel, Stefan

    2017-09-01

    Columnar silicon structures are proven as high performance anodes for high energy batteries paired with low (sulfur) or high (nickel-cobalt-aluminum oxide, NCA) voltage cathodes. The introduction of a fluorinated ether/sulfolane solvent mixture drastically improves the capacity retention for both battery types due to an improved solid electrolyte interface (SEI) on the surface of the silicon electrode which reduces irreversible reactions normally causing lithium loss and rapid capacity fading. For the lithium silicide/sulfur battery cycling stability is significantly improved as compared to a frequently used reference electrolyte (DME/DOL) reaching a constant coulombic efficiency (CE) as high as 98%. For the silicon/NCA battery with higher voltage, the addition of only small amounts of fluoroethylene carbonate (FEC) to the novel electrolyte leads to a stable capacity over at least 50 cycles and a CE as high as 99.9%. A high volumetric energy density close to 1000 Wh l-1 was achieved with the new electrolyte taking all inactive components of the stack into account for the estimation.

  18. The ocular response to extended wear of a high Dk silicone hydrogel contact lens.

    Science.gov (United States)

    Fonn, Desmond; MacDonald, Karen E; Richter, Doris; Pritchard, Nicola

    2002-05-01

    A four-month extended wear clinical trial was conducted to compare the ocular effects of a high Dk Balafilcon A silicone hydrogel lens and a low Dk HEMA 38.6 per cent H20 soft lens. Twenty-four subjects who were adapted to daily wear of soft lenses wore a high Dk lens in one eye and a low Dk HEMA lens in the other eye for four months on an extended wear basis after one week of daily wear. Thirteen progress evaluations were conducted using standard clinical procedures. Eighteen subjects (75 per cent) completed the study. The high Dk lens induced significantly less bulbar and limbal injection and corneal vascularisation than the low Dk HEMA lens (p Dk lens. A significant increase in myopia was found in the eyes wearing the low Dk HEMA lens (mean = 0.50 D, p Dk lens. Three subjects developed small infiltrates in the high Dk lens wearing eyes and significantly more post-lens debris was observed under the high Dk lens. Six subjects developed papillary conjunctivitis in the eye wearing silicone hydrogel lenses but only two of those were discontinued from the study. No hypoxia-related effects were observed with extended wear of the high Dk Balafilcon A silicone hydrogel lens.

  19. Characterisation and stabilisation of the surface region of a highly polished silicon crystal sphere

    International Nuclear Information System (INIS)

    Kenny, M.J.; Wielunski, L.S.

    1999-01-01

    Full text: Typically a single crystal silicon wafer has a native oxide layer a few nm thick which changes slowly with time. A number of parameters such as hydrocarbons, water vapour, storage environment can affect this layer. The thickness of the layer is also orientation dependent. In the case of a silicon sphere the situation becomes more complex, because all orientations are present and the process of polishing involves a higher pressure and also high local temperatures. A highly polished single crystal sphere 93.6 mm in diameter is being used to determine the Avogadro constant with an uncertainty of ≤ 1 x 10 -8 . This will then be used to obtain an atomic definition of the kilogram. The composition and structure of the surface oxide layer play an important role in this measurement. Firstly the density of the oxide layer is different from that of silicon. Secondly since the diameter is measured by optical interferometry, corrections must be applied for the phase change in the reflected light beam due to the surface layer. Thirdly the orientation dependence of the layer complicated the corrections to be applied. Fourthly if measurements are made over a period of time, any changes in the surface layer must be taken into account. Given the accuracy required in the determination, the surface layer is a determining factor in the final result. A number of techniques such as spectroscopic ellipsometry and ion beam analysis are being used to study the composition and structure of the surface of a silicon sphere. Cleaning techniques such as HF and low temperature ultraviolet (ozone) are being developed to produce a clean surface. The next step involves deposition of a stable and uniform surface oxide layer a few nm thick. Techniques being investigated for this include ultra violet ozone deposition at 450 deg C and plasma deposition. The paper describes work at the NML in achieving an appropriate stable surface on the silicon sphere

  20. Casting Characteristics of High Cerium Content Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D; Rios, O R; Sims, Z C; McCall, S K; Ott, R T

    2017-09-05

    This paper compares the castability of the near eutectic aluminum-cerium alloy system to the aluminum-silicon and aluminum-copper systems. The alloys are compared based on die filling capability, feeding characteristics and tendency to hot tear in both sand cast and permanent mold applications. The castability ranking of the binary Al–Ce systems is as good as the aluminum-silicon system with some deterioration as additional alloying elements are added. In alloy systems that use cerium in combination with common aluminum alloying elements such as silicon, magnesium and/or copper, the casting characteristics are generally better than the aluminum-copper system. In general, production systems for melting, de-gassing and other processing of aluminum-silicon or aluminum-copper alloys can be used without modification for conventional casting of aluminum-cerium alloys.

  1. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    secondary levels. In subject matter didactics, the question of content is more developed, but it is still mostly confined to teaching on lower levels. As for higher education didactics, discussions on selection of content are almost non-existent on the programmatic level. Nevertheless, teachers are forced...... curriculum, in higher education, and to generate analytical categories and criteria for selection of content, which can be used for systematic didactical reflection. The larger project also concerns reflection on and clarification of the concept of content, including the relation between content at the level......Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007...

  2. Formation of hypereutectic silicon particles in hypoeutectic Al-Si alloys under the influence of high-intensity ultrasonic vibration

    Directory of Open Access Journals (Sweden)

    Xiaogang Jian

    2013-03-01

    Full Text Available The modification of eutectic silicon is of general interest since fine eutectic silicon along with fine primary aluminum grains improves mechanical properties and ductilities. In this study, high intensity ultrasonic vibration was used to modify the complex microstructure of aluminum hypoeutectic alloys. The ultrasonic vibrator was placed at the bottom of a copper mold with molten aluminum. Hypoeutectic Al-Si alloy specimens with a unique in-depth profile of microstructure distribution were obtained. Polyhedral silicon particles, which should form in a hypereutectic alloy, were obtained in a hypoeutectic Al-Si alloy near the ultrasonic radiator where the silicon concentration was higher than the eutectic composition. The formation of hypereutectic silicon near the radiator surface indicates that high-intensity ultrasonic vibration can be used to influence the phase transformation process of metals and alloys. The size and morphology of both the silicon phase and the aluminum phase varies with increasing distance from the ultrasonic probe/radiator. Silicon morphology develops into three zones. Polyhedral primary silicon particles present in zone I, within 15 mm from the ultrasonic probe/radiator. Transition from hypereutectic silicon to eutectic silicon occurs in zone II about 15 to 20 祄 from the ultrasonic probe/radiator. The bulk of the ingot is in zone III and is hypoeutectic Al-Si alloy containing fine lamellar and fibrous eutectic silicon. The grain size is about 15 to 25 祄 in zone I, 25 to 35 祄 in zone II, and 25 to 55 祄 in zone III. The morphology of the primary ?Al phase is also changed from dendritic (in untreated samples to globular. Phase evolution during the solidification process of the alloy subjected to ultrasonic vibration is described.

  3. Information management for high content live cell imaging

    Directory of Open Access Journals (Sweden)

    White Michael RH

    2009-07-01

    Full Text Available Abstract Background High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. Results We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. Conclusion Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: fhttp://code.google.com/p/livecellim/

  4. Soft Functional Silicone Elastomers with High Dielectric Permittivty: Simple Additives vs. Cross-Linked Synthesized Copolymers

    DEFF Research Database (Denmark)

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

    Though dielectric elastomers (DEs) have many favorable properties, the issue of high driving voltages limits the commercial viability of the technology. Improved actuation at lower voltages can be obtained by decreasing the Young’s modulus and/or decreasing the dielectric permittivity of the elas......Though dielectric elastomers (DEs) have many favorable properties, the issue of high driving voltages limits the commercial viability of the technology. Improved actuation at lower voltages can be obtained by decreasing the Young’s modulus and/or decreasing the dielectric permittivity...... of the elastomer. A decrease in Young’s modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE whereas addition of high permittivity fillers such as metal oxides often increases Young’s modulus such that improved actuation is not accomplished. New soft...... silicone elastomers with high dielectric permittivity were prepared through the use of chloropropyl-functional silicones. One method was through the synthesis of modular cross-linkable chloropropyl-functional copolymers that allow for a high degree of chemical freedom such that a tuneable silicone...

  5. Highly Porous Silicon Embedded in a Ceramic Matrix: A Stable High-Capacity Electrode for Li-Ion Batteries.

    Science.gov (United States)

    Vrankovic, Dragoljub; Graczyk-Zajac, Magdalena; Kalcher, Constanze; Rohrer, Jochen; Becker, Malin; Stabler, Christina; Trykowski, Grzegorz; Albe, Karsten; Riedel, Ralf

    2017-11-28

    We demonstrate a cost-effective synthesis route that provides Si-based anode materials with capacities between 2000 and 3000 mAh·g Si -1 (400 and 600 mAh·g composite -1 ), Coulombic efficiencies above 99.5%, and almost 100% capacity retention over more than 100 cycles. The Si-based composite is prepared from highly porous silicon (obtained by reduction of silica) by encapsulation in an organic carbon and polymer-derived silicon oxycarbide (C/SiOC) matrix. Molecular dynamics simulations show that the highly porous silicon morphology delivers free volume for the accommodation of strain leading to no macroscopic changes during initial Li-Si alloying. In addition, a carbon layer provides an electrical contact, whereas the SiOC matrix significantly diminishes the interface between the electrolyte and the electrode material and thus suppresses the formation of a solid-electrolyte interphase on Si. Electrochemical tests of the micrometer-sized, glass-fiber-derived silicon demonstrate the up-scaling potential of the presented approach.

  6. High energy heavy ion beam lithography in silicon

    International Nuclear Information System (INIS)

    Rout, Bibhudutta; Dymnikov, Alexander D.; Zachry, Daniel P.; Eschenazi, Elia V.; Wang, Yongqiang Q.; Greco, Richard R.; Glass, Gary A.

    2007-01-01

    As high energy ions travel through a crystalline semiconductor materials they produce damage along the path which results in resistance to some of the wet chemical etching. A series of preliminary experiments have been performed at the Louisiana Accelerator Center (LAC) to examine the feasibility of irradiating high energy (keV-MeV) ions such as protons, xenon and gold through microscale masked structures on crystalline (n-type) Si substrates followed by wet chemical etch with KOH for attaining deep micromachining in Si. The results of these experiments are reported

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

    Science.gov (United States)

    Breneman, W. C.

    1978-01-01

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

  8. Method for creating high carbon content products from biomass oil

    Science.gov (United States)

    Parker, Reginald; Seames, Wayne

    2012-12-18

    In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

  9. Highly stressed carbon film coatings on silicon potential applications

    CERN Multimedia

    Sharda, T

    2002-01-01

    The fabrication of highly stressed and strongly adhered nanocrystalline diamond films on Si substrates is presented. A microwave plasma CVD method with controlled and continuous bias current density was used to grow the films. The stress/curvature of the films can be varied and controlled by altering the BCD. Potential applications for these films include particle physics and x-ray optics.

  10. The aluminium content of infant formulas remains too high.

    Science.gov (United States)

    Chuchu, Nancy; Patel, Bhavini; Sebastian, Blaise; Exley, Christopher

    2013-10-08

    Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content of aluminium. Herein, we have significantly extended the scope of the previous research and the aluminium content of 30 of the most widely available and often used infant formulas has been measured. Both ready-to-drink milks and milk powders were subjected to microwave digestion in the presence of 15.8 M HNO3 and 30% w/v H2O2 and the aluminium content of the digests was measured by TH GFAAS. Both ready-to-drink milks and milk powders were contaminated with aluminium. The concentration of aluminium across all milk products ranged from ca 100 to 430 μg/L. The concentration of aluminium in two soya-based milk products was 656 and 756 μg/L. The intake of aluminium from non-soya-based infant formulas varied from ca 100 to 300 μg per day. For soya-based milks it could be as high as 700 μg per day. All 30 infant formulas were contaminated with aluminium. There was no clear evidence that subsequent to the problem of aluminium being highlighted in a previous publication in this journal that contamination had been addressed and reduced. It is the opinion of the authors that regulatory and other non-voluntary methods are now required to reduce the aluminium content of infant formulas and thereby protect infants from chronic exposure to dietary aluminium.

  11. Method for producing evaporation inhibiting coating for protection of silicon--germanium and silicon--molybdenum alloys at high temperatures in vacuum

    Science.gov (United States)

    Chao, P.J.

    1974-01-01

    A method is given for protecting Si--Ge and Si-- Mo alloys for use in thermocouples. The alloys are coated with silicon to inhibit the evaporation of the alloys at high tempenatures in a vacuum. Specific means and methods are provided. (5 fig) (Official Gazette)

  12. Engineering properties for high kitchen waste content municipal solid waste

    Directory of Open Access Journals (Sweden)

    Wu Gao

    2015-12-01

    Full Text Available Engineering properties of municipal solid waste (MSW depend largely on the waste's initial composition and degree of degradation. MSWs in developing countries usually have a high kitchen waste content (called HKWC MSW. After comparing and analyzing the laboratory and field test results of physical composition, hydraulic properties, gas generation and gas permeability, and mechanical properties for HKWC MSW and low kitchen waste content MSW (called LKWC MSW, the following findings were obtained: (1 HKWC MSW has a higher initial water content (IWC than LKWC MSW, but the field capacities of decomposed HKWC and LKWC MSWs are similar; (2 the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW; (3 compared with LKWC MSW, HKWC MSW has a higher landfill gas (LFG generation rate but a shorter duration and a lower potential capacity; (4 the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW, but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW; and (5 the shear strength of HKWC MSW changes significantly with time and strain. Based on the differences of engineering properties between these two kinds of MSWs, the geo-environmental issues in HKWC MSW landfills were analyzed, including high leachate production, high leachate mounds, low LFG collection efficiency, large settlement and slope stability problem, and corresponding advice for the management and design of HKWC MSW landfills was recommended.

  13. Liquid alternative diesel fuels with high hydrogen content

    Energy Technology Data Exchange (ETDEWEB)

    Hancsok, Jenoe; Varga, Zoltan; Eller, Zoltan; Poelczmann, Gyoergy [Pannonia Univ., Veszprem (Hungary). MOL Dept. of Hydrocarbon Processing; Kasza, Tamas [MOL Hungarian Oil and Gas Plc., Szazhalombatta (Hungary)

    2013-06-01

    Mobility is a keystone of the sustainable development. In the operation of the vehicles as the tools of mobility internal combustion engines, so thus Diesel engines will play a remarkable role in the next decades. Beside fossil fuels - used for power these engines - liquid alternative fuels have higher and higher importance, because of their known advantages. During the presentation the categorization possibilities based on the chronology of their development and application will be presented. The importance of fuels with high hydrogen content will be reviewed. Research and development activity in the field of such kind of fuels will be presented. During this developed catalytic systems and main performance properties of the product will be presented which were obtained in case of biogasoils produced by special hydrocracking of natural triglycerides and in case of necessity followed by isomerization; furthermore in case of synthetic biogasoils obtained by the isomerization hydrocracking of Fischer-Tropsch paraffins produced from biomass based synthesis gas. Excellent combustion properties (cetane number > 65-75), good cold flow properties and reduced harmful material emission due to the high hydrogen content (C{sub n}H{sub 2n+2}) are highlighted. Finally production possibilities of linear and branched paraffins based on lignocelluloses are briefly reviewed. Summarizing it was concluded that liquid hydrocarbons with high isoparaffin content are the most suitable fuels regarding availability, economical and environmental aspects, namely the sustainable development. (orig.)

  14. Amorphous Silicon-Germanium Films with Embedded Nanocrystals for Thermal Detectors with Very High Sensitivity

    Directory of Open Access Journals (Sweden)

    Cesar Calleja

    2016-01-01

    Full Text Available We have optimized the deposition conditions of amorphous silicon-germanium films with embedded nanocrystals in a plasma enhanced chemical vapor deposition (PECVD reactor, working at a standard frequency of 13.56 MHz. The objective was to produce films with very large Temperature Coefficient of Resistance (TCR, which is a signature of the sensitivity in thermal detectors (microbolometers. Morphological, electrical, and optical characterization were performed in the films, and we found optimal conditions for obtaining films with very high values of thermal coefficient of resistance (TCR = 7.9% K−1. Our results show that amorphous silicon-germanium films with embedded nanocrystals can be used as thermosensitive films in high performance infrared focal plane arrays (IRFPAs used in commercial thermal cameras.

  15. Highly Sensitive Bulk Silicon Chemical Sensors with Sub-5 nm Thin Charge Inversion Layers.

    Science.gov (United States)

    Fahad, Hossain M; Gupta, Niharika; Han, Rui; Desai, Sujay B; Javey, Ali

    2018-03-27

    There is an increasing demand for mass-producible, low-power gas sensors in a wide variety of industrial and consumer applications. Here, we report chemical-sensitive field-effect-transistors (CS-FETs) based on bulk silicon wafers, wherein an electrostatically confined sub-5 nm thin charge inversion layer is modulated by chemical exposure to achieve a high-sensitivity gas-sensing platform. Using hydrogen sensing as a "litmus" test, we demonstrate large sensor responses (>1000%) to 0.5% H 2 gas, with fast response (<60 s) and recovery times (<120 s) at room temperature and low power (<50 μW). On the basis of these performance metrics as well as standardized benchmarking, we show that bulk silicon CS-FETs offer similar or better sensing performance compared to emerging nanostructures semiconductors while providing a highly scalable and manufacturable platform.

  16. Cryogenic Etching of High Aspect Ratio 400 nm Pitch Silicon Gratings.

    Science.gov (United States)

    Miao, Houxun; Chen, Lei; Mirzaeimoghri, Mona; Kasica, Richard; Wen, Han

    2016-10-01

    The cryogenic process and Bosch process are two widely used processes for reactive ion etching of high aspect ratio silicon structures. This paper focuses on the cryogenic deep etching of 400 nm pitch silicon gratings with various etching mask materials including polymer, Cr, SiO 2 and Cr-on-polymer. The undercut is found to be the key factor limiting the achievable aspect ratio for the direct hard masks of Cr and SiO 2 , while the etch selectivity responds to the limitation of the polymer mask. The Cr-on-polymer mask provides the same high selectivity as Cr and reduces the excessive undercut introduced by direct hard masks. By optimizing the etching parameters, we etched a 400 nm pitch grating to ≈ 10.6 μ m depth, corresponding to an aspect ratio of ≈ 53.

  17. Amorphous Silicon-Germanium Films with Embedded Nano crystals for Thermal Detectors with Very High Sensitivity

    International Nuclear Information System (INIS)

    Calleja, C.; Torres, A.; Rosales-Quintero, P.; Moreno, M.

    2016-01-01

    We have optimized the deposition conditions of amorphous silicon-germanium films with embedded nano crystals in a plasma enhanced chemical vapor deposition (PECVD) reactor, working at a standard frequency of 13.56 MHz. The objective was to produce films with very large Temperature Coefficient of Resistance (TCR), which is a signature of the sensitivity in thermal detectors (micro bolometers). Morphological, electrical, and optical characterization were performed in the films, and we found optimal conditions for obtaining films with very high values of thermal coefficient of resistance (TCR = 7.9%K -1 ). Our results show that amorphous silicon-germanium films with embedded nano crystals can be used as thermo sensitive films in high performance infrared focal plane arrays (IRFPAs) used in commercial thermal cameras.

  18. Simultaneous high crystallinity and sub-bandgap optical absorptance in hyperdoped black silicon using nanosecond laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Franta, Benjamin, E-mail: bafranta@gmail.com; Pastor, David; Gandhi, Hemi H.; Aziz, Michael J.; Mazur, Eric [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Rekemeyer, Paul H.; Gradečak, Silvija [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-12-14

    Hyperdoped black silicon fabricated with femtosecond laser irradiation has attracted interest for applications in infrared photodetectors and intermediate band photovoltaics due to its sub-bandgap optical absorptance and light-trapping surface. However, hyperdoped black silicon typically has an amorphous and polyphasic polycrystalline surface that can interfere with carrier transport, electrical rectification, and intermediate band formation. Past studies have used thermal annealing to obtain high crystallinity in hyperdoped black silicon, but thermal annealing causes a deactivation of the sub-bandgap optical absorptance. In this study, nanosecond laser annealing is used to obtain high crystallinity and remove pressure-induced phases in hyperdoped black silicon while maintaining high sub-bandgap optical absorptance and a light-trapping surface morphology. Furthermore, it is shown that nanosecond laser annealing reactivates the sub-bandgap optical absorptance of hyperdoped black silicon after deactivation by thermal annealing. Thermal annealing and nanosecond laser annealing can be combined in sequence to fabricate hyperdoped black silicon that simultaneously shows high crystallinity, high above-bandgap and sub-bandgap absorptance, and a rectifying electrical homojunction. Such nanosecond laser annealing could potentially be applied to non-equilibrium material systems beyond hyperdoped black silicon.

  19. Highly sensitive and selective detection of dopamine using one-pot synthesized highly photoluminescent silicon nanoparticles.

    Science.gov (United States)

    Zhang, Xiaodong; Chen, Xiaokai; Kai, Siqi; Wang, Hong-Yin; Yang, Jingjing; Wu, Fu-Gen; Chen, Zhan

    2015-03-17

    A simple and highly efficient method for dopamine (DA) detection using water-soluble silicon nanoparticles (SiNPs) was reported. The SiNPs with a high quantum yield of 23.6% were synthesized by using a one-pot microwave-assisted method. The fluorescence quenching capability of a variety of molecules on the synthesized SiNPs has been tested; only DA molecules were found to be able to quench the fluorescence of these SiNPs effectively. Therefore, such a quenching effect can be used to selectively detect DA. All other molecules tested have little interference with the dopamine detection, including ascorbic acid, which commonly exists in cells and can possibly affect the dopamine detection. The ratio of the fluorescence intensity difference between the quenched and unquenched cases versus the fluorescence intensity without quenching (ΔI/I) was observed to be linearly proportional to the DA analyte concentration in the range from 0.005 to 10.0 μM, with a detection limit of 0.3 nM (S/N = 3). To the best of our knowledge, this is the lowest limit for DA detection reported so far. The mechanism of fluorescence quenching is attributed to the energy transfer from the SiNPs to the oxidized dopamine molecules through Förster resonance energy transfer. The reported method of SiNP synthesis is very simple and cheap, making the above sensitive and selective DA detection approach using SiNPs practical for many applications.

  20. High-performance silicon photonics technology for telecommunications applications.

    Science.gov (United States)

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

    2014-04-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

  1. High-performance silicon photonics technology for telecommunications applications

    International Nuclear Information System (INIS)

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Yamamoto, Tsuyoshi; Ishikawa, Yasuhiko; Wada, Kazumi

    2014-01-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge–based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge–based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications. (review)

  2. High-performance silicon photonics technology for telecommunications applications

    Science.gov (United States)

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

    2014-04-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

  3. High-contrast gratings for long-wavelength laser integration on silicon

    Science.gov (United States)

    Sciancalepore, Corrado; Descos, Antoine; Bordel, Damien; Duprez, Hélène; Letartre, Xavier; Menezo, Sylvie; Ben Bakir, Badhise

    2014-02-01

    Silicon photonics is increasingly considered as the most promising way-out to the relentless growth of data traffic in today's telecommunications infrastructures, driving an increase in transmission rates and computing capabilities. This is in fact challenging the intrinsic limit of copper-based, short-reach interconnects and microelectronic circuits in data centers and server architectures to offer enough modulation bandwidth at reasonable power dissipation. In the context of the heterogeneous integration of III-V direct-bandgap materials on silicon, optics with high-contrast metastructures enables the efficient implementation of optical functions such as laser feedback, input/output (I/O) to active/passive components, and optical filtering, while heterogeneous integration of III-V layers provides sufficient optical gain, resulting in silicon-integrated laser sources. The latest ensure reduced packaging costs and reduced footprint for the optical transceivers, a key point for the short reach communications. The invited talk will introduce the audience to the latest breakthroughs concerning the use of high-contrast gratings (HCGs) for the integration of III-V-on-Si verticalcavity surface-emitting lasers (VCSELs) as well as Fabry-Perot edge-emitters (EELs) in the main telecom band around 1.55 μm. The strong near-field mode overlap within HCG mirrors can be exploited to implement unique optical functions such as dense wavelength division multiplexing (DWDM): a 16-λ100-GHz-spaced channels VCSEL array is demonstrated. On the other hand, high fabrication yields obtained via molecular wafer bonding of III-V alloys on silicon-on-insulator (SOI) conjugate excellent device performances with cost-effective high-throughput production, supporting industrial needs for a rapid research-to-market transfer.

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

    Science.gov (United States)

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

    2017-03-21

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

  5. An improved PIN photodetector with integrated JFET on high-resistivity silicon

    International Nuclear Information System (INIS)

    Dalla Betta, Gian-Franco; Piemonte, Claudio; Boscardin, Maurizio; Gregori, Paolo; Zorzi, Nicola; Fazzi, Alberto; Pignatel, Giorgio U.

    2006-01-01

    We report on a PIN photodetector integrated with a Junction Field Effect Transistor (JFET) on a high-resistivity silicon substrate. Owing to a modified fabrication technology, the electrical and noise characteristics of the JFET transistor have been enhanced with respect to the previous versions of the device, allowing the performance to be significantly improved. In this paper, the main design and technological aspects relevant to the proposed structure are addressed and experimental results from the electrical characterization are discussed

  6. High-efficiency amorphous silicon solar cell on a periodic nanocone back reflector

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Ching-Mei; Cui, Yi [Department of Materials Science and Engineering, Durand Building, 496 Lomita Mall, Stanford University, Stanford, CA 94305-4034 (United States); Battaglia, Corsin; Pahud, Celine; Haug, Franz-Josef; Ballif, Christophe [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Rue Breguet 2, 2000 Neuchatel (Switzerland); Ruan, Zhichao; Fan, Shanhui [Department of Electrical Engineering, Stanford University (United States)

    2012-06-15

    An amorphous silicon solar cell on a periodic nanocone back reflector with a high 9.7% initial conversion efficiency is presented. The optimized back-reflector morphology provides powerful light trapping and enables excellent electrical cell performance. Up-scaling to industrial production of large-area modules should be possible using nanoimprint lithography. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Large-size high-performance transparent amorphous silicon sensors for laser beam position detection

    International Nuclear Information System (INIS)

    Calderon, A.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Sobron, M.; Vila, I.; Virto, A.L.; Alberdi, J.; Arce, P.; Barcala, J.M.; Calvo, E.; Ferrando, A.; Josa, M.I.; Luque, J.M.; Molinero, A.; Navarrete, J.; Oller, J.C.; Yuste, C.; Koehler, C.; Lutz, B.; Schubert, M.B.; Werner, J.H.

    2006-01-01

    We present the measured performance of a new generation of semitransparent amorphous silicon position detectors. They have a large sensitive area (30x30mm 2 ) and show good properties such as a high response (about 20mA/W), an intrinsic position resolution better than 3μm, a spatial-point reconstruction precision better than 10μm, deflection angles smaller than 10μrad and a transmission power in the visible and NIR higher than 70%

  8. Dispersion engineering of thick high-Q silicon nitride ring-resonators via atomic layer deposition.

    Science.gov (United States)

    Riemensberger, Johann; Hartinger, Klaus; Herr, Tobias; Brasch, Victor; Holzwarth, Ronald; Kippenberg, Tobias J

    2012-12-03

    We demonstrate dispersion engineering of integrated silicon nitride based ring resonators through conformal coating with hafnium dioxide deposited on top of the structures via atomic layer deposition. Both, magnitude and bandwidth of anomalous dispersion can be significantly increased. The results are confirmed by high resolution frequency-comb-assisted-diode-laser spectroscopy and are in very good agreement with the simulated modification of the mode spectrum.

  9. MICROSTRUCTURING OF SILICON SINGLE CRYSTALS BY FIBER LASER IN HIGH-SPEED SCANNING MODE

    Directory of Open Access Journals (Sweden)

    T. A. Trifonova

    2015-11-01

    Full Text Available Subject of Study. The surface structure of the silicon wafers (substrate with a thermally grown silicon dioxide on the surface (of SiO2/Si is studied after irradiation by pulse fiber laser of ILI-1-20 type. The main requirements for exposure modes of the system are: the preservation of the integrity of the film of silicon dioxide in the process of microstructuring and the absence of interference of surrounding irradiated areas of the substrate. Method. Studies were carried out on silicon wafers KEF-4,5 oriented in the crystallographic plane (111 with the source (natural silicon dioxide (SiO2 with thickness of about 4 nm, and SiO2 with 40 nm and 150 nm thickness, grown by thermal oxidation in moist oxygen. Also, wafers KHB-10 oriented in the plane (100 with 500 nm thickness of thermal oxide were investigated. Irradiation of SiO2/Si system was produced by laser complex based on ytterbium fiber pulse laser ILI-1-20. Nominal output power of the laser was 20 W, and the laser wavelength was λ = 1062 nm. Irradiation was carried out by a focused beam spot with a diameter of 25 microns and a pulse repetition rate of 99 kHz. The samples with 150 nm and 40 nm thickness of SiO2 were irradiated at a power density equal to 1,2·102 W/cm2, and the samples of SiO2 with 500 nm thickness were irradiated at a power density equal to 2,0·102 W/cm2. Scanning was performed using a two-axis Coordinate Scanning Device based on VM2500+ drives with control via a PC with the software package "SinMarkTM." Only one scan line was used at the maximum speed of the beam equal to 8750 mm/s. Morphology control of the irradiated samples was conducted by an optical microscope ZeissA1M with high-resolution CCD array. A scanning probe microscope Nanoedicator of the NT-MDT company was used for structural measurements. Main Results. It has been shown that at a single exposure of high-frequency pulsed laser radiation on SiO2/Si system, with maintaining the integrity of the SiO2 film

  10. A novel high pressure, high temperature vessel used to conduct long-term stability measurements of silicon MEMS pressure transducers

    Science.gov (United States)

    Wisniewiski, David

    2014-03-01

    The need to quantify and to improve long-term stability of pressure transducers is a persistent requirement from the aerospace sector. Specifically, the incorporation of real-time pressure monitoring in aircraft landing gear, as exemplified in Tire Pressure Monitoring Systems (TPMS), has placed greater demand on the pressure transducer for improved performance and increased reliability which is manifested in low lifecycle cost and minimal maintenance downtime through fuel savings and increased life of the tire. Piezoresistive (PR) silicon MEMS pressure transducers are the primary choice as a transduction method for this measurement owing to their ability to be designed for the harsh environment seen in aircraft landing gear. However, these pressure transducers are only as valuable as the long-term stability they possess to ensure reliable, real-time monitoring over tens of years. The "heart" of the pressure transducer is the silicon MEMS element, and it is at this basic level where the long-term stability is established and needs to be quantified. A novel High Pressure, High Temperature (HPHT) vessel has been designed and constructed to facilitate this critical measurement of the silicon MEMS element directly through a process of mechanically "floating" the silicon MEMS element while being subjected to the extreme environments of pressure and temperature, simultaneously. Furthermore, the HPHT vessel is scalable to permit up to fifty specimens to be tested at one time to provide a statistically significant data population on which to draw reasonable conclusions on long-term stability. With the knowledge gained on the silicon MEMS element, higher level assembly to the pressure transducer envelope package can also be quantified as to the build-effects contribution to long-term stability in the same HPHT vessel due to its accommodating size. Accordingly, a HPHT vessel offering multiple levels of configurability and robustness in data measurement is presented, along

  11. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry\\'s most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  12. Effect of wheel speed on magnetic and mechanical properties of melt spun Fe-6.5 wt.% Si high silicon steel

    Science.gov (United States)

    Ouyang, Gaoyuan; Jensen, Brandt; Tang, Wei; Dennis, Kevin; Macziewski, Chad; Thimmaiah, Srinivasa; Liang, Yongfeng; Cui, Jun

    2018-05-01

    Fe-Si electric steel is the most widely used soft magnetic material in electric machines and transformers. Increasing the silicon content from 3.2 wt.% to 6.5 wt.% brings about large improvement in the magnetic and electrical properties. However, 6.5 wt.% silicon steel is inherited with brittleness owing to the formation of B2 and D03 ordered phase. To obtain ductility in Fe-6.5wt.% silicon steel, the ordered phase has to be bypassed with methods like rapid cooling. In present paper, the effect of cooling rate on magnetic and mechanical properties of Fe-6.5wt.% silicon steel is studied by tuning the wheel speed during melt spinning process. The cooling rate significantly alters the ordering and microstructure, and thus the mechanical and magnetic properties. X-ray diffraction data shows that D03 ordering was fully suppressed at high wheel speeds but starts to nucleate at 10m/s and below, which correlates with the increase of Young's modulus towards low wheel speeds as tested by nanoindentation. The grain sizes of the ribbons on the wheel side decrease with increasing wheel speeds, ranging from ˜100 μm at 1m/s to ˜8 μm at 30m/s, which lead to changes in coercivity.

  13. High-quality GaN nanowires grown on Si and porous silicon by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Shekari, L., E-mail: lsg09_phy089@student.usm.my [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Ramizy, A.; Omar, K.; Hassan, H. Abu; Hassan, Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer A new kind of substrate (porous silicon) was used. Black-Right-Pointing-Pointer Also this research introduces an easy and safe method to grow high quality GaN NWs. Black-Right-Pointing-Pointer This is a new growth process to decrease the cost, complexity of growth of GaN NWs. Black-Right-Pointing-Pointer It is a controllable method to synthesize GaN NWs by thermal evaporation. - Abstract: Nanowires (NWs) of GaN thin films were prepared on as-grown Si (1 1 1) and porous silicon (PS) substrates using thermal evaporation method. The film growth produced high-quality wurtzite GaN NWs. The size, morphology, and nanostructures of the crystals were investigated through scanning electron microscopy, high-resolution X-ray diffraction and photoluminescence spectroscopy. The NWs grown on porous silicon were thinner, longer and denser compared with those on as-grown Si. The energy band gap of the NWs grown on PS was larger than that of NWs on as-grown Si. This is due to the greater quantum confinement effects of the crystalline structure of the NWs grown on PS.

  14. Active phase correction of high resolution silicon photonic arrayed waveguide gratings.

    Science.gov (United States)

    Gehl, M; Trotter, D; Starbuck, A; Pomerene, A; Lentine, A L; DeRose, C

    2017-03-20

    Arrayed waveguide gratings provide flexible spectral filtering functionality for integrated photonic applications. Achieving narrow channel spacing requires long optical path lengths which can greatly increase the footprint of devices. High index contrast waveguides, such as those fabricated in silicon-on-insulator wafers, allow tight waveguide bends which can be used to create much more compact designs. Both the long optical path lengths and the high index contrast contribute to significant optical phase error as light propagates through the device. Therefore, silicon photonic arrayed waveguide gratings require active or passive phase correction following fabrication. Here we present the design and fabrication of compact silicon photonic arrayed waveguide gratings with channel spacings of 50, 10 and 1 GHz. The largest device, with 11 channels of 1 GHz spacing, has a footprint of only 1.1 cm2. Using integrated thermo-optic phase shifters, the phase error is actively corrected. We present two methods of phase error correction and demonstrate state-of-the-art cross-talk performance for high index contrast arrayed waveguide gratings. As a demonstration of possible applications, we perform RF channelization with 1 GHz resolution. Additionally, we generate unique spectral filters by applying non-zero phase offsets calculated by the Gerchberg Saxton algorithm.

  15. Auto Detection For High Level Water Content For Oil Well

    Science.gov (United States)

    Janier, Josefina Barnachea; Jumaludin, Zainul Arifin B.

    2010-06-01

    Auto detection of high level water content for oil well is a system that measures the percentage of water in crude oil. This paper aims to discuss an auto detection system for measuring the content of water level in crude oil which is applicable for offshore and onshore oil operations. Data regarding water level content from wells can be determined by using automation thus, well with high water level can be determined immediately whether to be closed or not from operations. Theoretically the system measures the percentage of two- fluid mixture where the fluids have different electrical conductivities which are water and crude oil. The system made use of grid sensor which is a grid pattern like of horizontal and vertical wires. When water occupies the space at the intersection of vertical and horizontal wires, an electrical signal is detected which proved that water completed the circuit path in the system. The electrical signals are counted whereas the percentage of water is determined from the total electrical signals detected over electrical signals provided. Simulation of the system using the MultiSIM showed that the system provided the desired result.

  16. Fabrication of wear-resistant silicon microprobe tips for high-speed surface roughness scanning devices

    Science.gov (United States)

    Wasisto, Hutomo Suryo; Yu, Feng; Doering, Lutz; Völlmeke, Stefan; Brand, Uwe; Bakin, Andrey; Waag, Andreas; Peiner, Erwin

    2015-05-01

    Silicon microprobe tips are fabricated and integrated with piezoresistive cantilever sensors for high-speed surface roughness scanning systems. The fabrication steps of the high-aspect-ratio silicon microprobe tips were started with photolithography and wet etching of potassium hydroxide (KOH) resulting in crystal-dependent micropyramids. Subsequently, thin conformal wear-resistant layer coating of aluminum oxide (Al2O3) was demonstrated on the backside of the piezoresistive cantilever free end using atomic layer deposition (ALD) method in a binary reaction sequence with a low thermal process and precursors of trimethyl aluminum and water. The deposited Al2O3 layer had a thickness of 14 nm. The captured atomic force microscopy (AFM) image exhibits a root mean square deviation of 0.65 nm confirming the deposited Al2O3 surface quality. Furthermore, vacuum-evaporated 30-nm/200-nm-thick Au/Cr layers were patterned by lift-off and served as an etch mask for Al2O3 wet etching and in ICP cryogenic dry etching. By using SF6/O2 plasma during inductively coupled plasma (ICP) cryogenic dry etching, micropillar tips were obtained. From the preliminary friction and wear data, the developed silicon cantilever sensor has been successfully used in 100 fast measurements of 5- mm-long standard artifact surface with a speed of 15 mm/s and forces of 60-100 μN. Moreover, the results yielded by the fabricated silicon cantilever sensor are in very good agreement with those of calibrated profilometer. These tactile sensors are targeted for use in high-aspect-ratio microform metrology.

  17. Corrosion Performance of Inconel 625 in High Sulphate Content

    Science.gov (United States)

    Ismail, Azzura

    2016-05-01

    Inconel 625 (UNS N06625) is a type of nickel-chromium-molybdenum alloy with excellent corrosion resistance in a wide range of corrosive media, being especially resistant to pitting and crevice corrosion. However, in aggressive environment, Inconel 625 will suffer corrosion attack like other metals. This research compared the corrosion performance of Inconel 625 when exposed to higher sulphate content compared to real seawater. The results reveal that Inconel 625 is excellent in resist the corrosion attack in seawater. However, at increasing temperature, the corrosion resistance of this metal decrease. The performance is same in seawater with high sulphate content at increasing temperature. It can be concluded that sulphate promote perforation on Inconel 625 and become aggressive agents that accelerate the corrosion attack.

  18. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  19. Microcyst response to high Dk/t silicone hydrogel contact lenses.

    Science.gov (United States)

    Keay, L; Sweeney, D F; Jalbert, I; Skotnitsky, C; Holden, B A

    2000-11-01

    To investigate the microcyst response to extended wear (EW) with high oxygen transmissible (Dk/t) silicone hydrogel lenses. Microcysts were monitored for 12 months in subjects wearing low Dk/t hydrogel lenses on a 6-night EW schedule or high Dk/t hydrogel lenses on a 30-night EW schedule. Subjects wearing low Dk/t lenses transferred to the high Dk/t EW lenses and schedule after 12 months and were monitored for a further 6 months. The mean number of microcysts did not deviate from baseline in the high Dk/t group. Microcysts in the low Dk/t group increased over 12 months, and more microcysts were observed in low Dk/t lens wearers compared with high Dk/t lens wearers after 3 months. Microcysts increased in 50% of subjects 1 week after transfer to high Dk/t lenses and returned to baseline levels seen with high Dk/t lens wear within 3 months. EW with high Dk/t silicone hydrogel lenses did not cause an increase in microcyst numbers. It is not necessary to discontinue lens wear with patients who transfer from low to high Dk/t lenses because the increase in microcysts is transitory. This result has implications for practitioners when fitting and assessing the success of high Dk/t hydrogel lenses.

  20. Effect of fabrication parameters on morphological and optical properties of highly doped p-porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Maryam, E-mail: mar.zare@gmail.com [Young Researchers Club, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr (Iran, Islamic Republic of); Shokrollahi, Abbas [Young Researchers Club, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr (Iran, Islamic Republic of); Seraji, Faramarz E. [Optical Communication Group, Iran Telecom Research Center, Tehran (Iran, Islamic Republic of)

    2011-09-01

    Porous silicon (PS) layers were fabricated by anodization of low resistive (highly doped) p-type silicon in HF/ethanol solution, by varying current density, etching time and HF concentration. Atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) analyses were used to investigate the physical properties and reflection spectrum was used to investigate the optical behavior of PS layers in different fabrication conditions. Vertically aligned mesoporous morphology is observed in fabricated films and with HF concentration higher than 20%. The dependence of porosity, layer thickness and rms roughness of the PS layer on current density, etching time and composition of electrolyte is also observed in obtained results. Correlation between reflectivity and fabrication parameters was also explored. Thermal oxidation was performed on some mesoporous layers that resulted in changes of surface roughness, mean height and reflectivity of the layers.

  1. Significantly High Modulation Efficiency of Compact Graphene Modulator Based on Silicon Waveguide.

    Science.gov (United States)

    Shu, Haowen; Su, Zhaotang; Huang, Le; Wu, Zhennan; Wang, Xingjun; Zhang, Zhiyong; Zhou, Zhiping

    2018-01-17

    We theoretically and experimentally demonstrate a significantly large modulation efficiency of a compact graphene modulator based on a silicon waveguide using the electro refractive effect of graphene. The modulation modes of electro-absorption and electro-refractive can be switched with different applied voltages. A high extinction ratio of 25 dB is achieved in the electro-absorption modulation mode with a driving voltage range of 0 V to 1 V. For electro-refractive modulation, the driving voltage ranges from 1 V to 3 V with a 185-pm spectrum shift. The modulation efficiency of 1.29 V · mm with a 40-μm interaction length is two orders of magnitude higher than that of the first reported graphene phase modulator. The realisation of phase and intensity modulation with graphene based on a silicon waveguide heralds its potential application in optical communication and optical interconnection systems.

  2. Ultracompact high-efficiency polarising beam splitter based on silicon nanobrick arrays.

    Science.gov (United States)

    Zheng, Guoxing; Liu, Guogen; Kenney, Mitchell Guy; Li, Zile; He, Ping'an; Li, Song; Ren, Zhi; Deng, Qiling

    2016-03-21

    Since the transmission of anisotropic nano-structures is sensitive to the polarisation of an incident beam, a novel polarising beam splitter (PBS) based on silicon nanobrick arrays is proposed. With careful design of such structures, an incident beam with polarisation direction aligned with the long axis of the nanobrick is almost totally reflected (~98.5%), whilst that along the short axis is nearly totally transmitted (~94.3%). More importantly, by simply changing the width of the nanobrick we can shift the peak response wavelength from 1460 nm to 1625 nm, covering S, C and L bands of the fiber telecommunications windows. The silicon nanobrick-based PBS can find applications in many fields which require ultracompactness, high efficiency, and compatibility with semiconductor industry technologies.

  3. High-stability transparent amorphous oxide TFT with a silicon-doped back-channel layer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyoung-Rae; Park, Jea-Gun [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We significantly reduced various electrical instabilities of amorphous indium gallium zinc oxide thin-film transistors (TFTs) by using the co-deposition of silicon on an a-IGZO back channel. This process showed improved stability of the threshold voltage (V{sub th}) under high temperature and humidity and negative gate-bias illumination stress (NBIS) without any reduction of IDS. The enhanced stability was achieved with silicon, which has higher metal-oxide bonding strengths than gallium does. Additionally, SiO{sub x} distributed on the a-IGZO surface reduced the adsorption and the desorption of H{sub 2}O and O{sub 2}. This process is applicable to the TFT manufacturing process with a variable sputtering target.

  4. Properties of CMOS devices and circuits fabricated on high-resistivity, detector-grade silicon

    International Nuclear Information System (INIS)

    Holland, S.

    1991-11-01

    A CMOS process that is compatible with silicon p-i-n radiation detectors has been developed and characterized. A total of twelve mask layers are used in the process. The NMOS device is formed in a retrograde well while the PMOS device is fabricated directly in the high-resistivity silicon. Isolation characteristics are similar to a standard foundary CMOS process. Circuit performance using 3 μm design rules has been evaluated. The measured propagation delay and power-delay product for a 51-stage ring oscillator was 1.5 ns and 43 fJ, respectively. Measurements on a simple cascode amplifier results in a gain-bandwidth product of 200 MHz at a bias current of 15 μA. The input-referred noise of the cascode amplifier is 20 nV/√Hz at 1 MHz

  5. High-voltage electron-microscopical observation of crack-tip dislocations in silicon crystals

    International Nuclear Information System (INIS)

    Tanaka, Masaki; Higashida, Kenji

    2005-01-01

    Crack-tip dislocations in silicon single crystals were observed by high-voltage electron microscopy. Cracks were introduced into silicon wafers at room temperature by a Vickers indenter. The indented specimens were annealed at 823 K in order to activate dislocation emission from the crack tip under the residual stress due to the indentation. In the specimen without annealing, no dislocations were observed around the crack. On the other hand, in the specimen after the annealing, the aspect of the early stage of dislocation emission was observed, where dislocations were emitted not as a perfect dislocation but as a partial dislocation in the hinge-type plastic zone. Prominent dislocation arrays that were emitted from a crack tip were also observed, and they were found to be of shielding type, which increases the fracture toughness of those crystals

  6. Variation of minority charge carrier lifetime in high-resistance p-type silicon under irradiation

    International Nuclear Information System (INIS)

    Basheleishvili, Z.V.; Garnyk, V.S.; Gorin, S.N.; Pagava, T.A.

    1984-01-01

    The minority carrier lifetime (tau) variation was studied in the process of p-type silicon bombardment with fast 8 MeV electrons. The irradiation and all measurements were carried out at room temperature. The tau quantity was measured by the photoconductivity attenuation method at a low injection level 20% measurement error; the resistivity was measured by the four-probe method (10% error). The resistivity and minority charge carrier lifetime tau are shown to increase with the exposure dose. It is supposed that as radiation dose increases, the rearrangement of the centres responsible for reducing the lifetime occurs and results in a tau increase in the material being irradiated, however the tau value observed in the original samples is not attained. The restoration of the minority carrier lifetime in p-type high-resistance silicon with a growing exposure dose might proceed due to reduction in the free carrier concentration

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-11-01

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

  8. Radiation hardness of silicon detectors - a challenge from high-energy physics

    CERN Document Server

    Lindström, G; Fretwurst, E

    1999-01-01

    An overview of the radiation-damage-induced problems connected with the application of silicon particle detectors in future high-energy physics experiments is given. Problems arising from the expected hadron fluences are summarized and the use of the nonionizing energy loss for normalization of bulk damage is explained. The present knowledge on the deterioration effects caused by irradiation is described leading to an appropriate modeling. Examples are given for a correlation between the change in the macroscopic performance parameters and effects to be seen on the microscopic level by defect analysis. Finally possible ways are out-lined for improving the radiation tolerance of silicon detectors either by operational conditions, process technology or defect engineering.

  9. High-silicon 238PuO2 fuel characterization study: Half module impact tests

    International Nuclear Information System (INIS)

    Reimus, M.A.H.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements. The modular GPHS design was developed to address both survivability during launch abort and return from orbit. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs to a variety of fragment- impact, aging, atmospheric reentry, and Earth-impact conditions. The evaluations documented in this report are part of an ongoing program to determine the effect of fuel impurities on the response of the heat source to conditions baselined during the Galileo/Ulysses test program. In the first two tests in this series, encapsulated GPHS fuel pellets containing high levels of silicon were aged, loaded into GPHS module halves, and impacted against steel plates. The results show no significant differences between the response of these capsules and the behavior of relatively low-silicon fuel pellets tested previously

  10. Selective tuning of high-Q silicon photonic crystal nanocavities via laser-assisted local oxidation.

    Science.gov (United States)

    Chen, Charlton J; Zheng, Jiangjun; Gu, Tingyi; McMillan, James F; Yu, Mingbin; Lo, Guo-Qiang; Kwong, Dim-Lee; Wong, Chee Wei

    2011-06-20

    We examine the cavity resonance tuning of high-Q silicon photonic crystal heterostructures by localized laser-assisted thermal oxidation using a 532 nm continuous wave laser focused to a 2.5 μm radius spot-size. The total shift is consistent with the parabolic rate law. A tuning range of up to 8.7 nm is achieved with ∼ 30 mW laser powers. Over this tuning range, the cavity Qs decreases from 3.2×10(5) to 1.2×10(5). Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.

  11. Improved contact metallization for high efficiency EFG polycrystalline silicon solar cells

    International Nuclear Information System (INIS)

    Dube, C.E.; Gonsiorawski, R.C.

    1990-01-01

    Improvements in the performance of polycrystalline silicon solar cells based on a novel, laser patterned contact process are described. Small lots of cells having an average conversion efficiency of 14 + %, with several cells approaching 15%, are reported for cells of 45 cm 2 area. The high efficiency contact design is based on YAG laser patterning of the silicon nitride anti-reflection coating. The Cu metallization is done using light-induced plating, with the cell providing the driving voltage for the plating process. The Cu electrodeposits into the laser defined windows in the AR coating for reduced contact area, following which the Cu bridges on top of the Ar coating to form a continuous finger pattern. The higher cell conversion efficiency is attributed to reduced shadow loss, higher junction quality, and reduced metal-semiconductor interfacial area

  12. Some considerations on silicone oil in high-current and energy-disconnecting mechanisms

    International Nuclear Information System (INIS)

    Vogel, H.F.

    1984-03-01

    Silicone oil is considered inflammable. The dissociation products generated by an electric arc under silicone oil are known to form a highly explosive mixture with air. We calculate the arc energy required for dissociation to be 32 kJ per liter of gas mixture at standard pressure and temperature. We calculate the arc voltage gradient at a pressure of 50 atm and current density of 1 kA/mm 2 to be 0.5 kV/cm, resulting in an arc voltage of several kV, depending on the arc length. In a multikiloampere arc, the resulting arc power is likely to cause a pressure of many atmospheres in a shock wave

  13. High Temperature All Silicon-Carbide (SiC) DC Motor Drives for Venus Exploration Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project seeks to prove the feasibility of creating high-temperature silicon-carbide (SiC) based motor drives for...

  14. A silicon-based electrochemical sensor for highly sensitive, specific, label-free and real-time DNA detection

    International Nuclear Information System (INIS)

    Guo, Yuanyuan; Su, Shao; Wei, Xinpan; Zhong, Yiling; Su, Yuanyuan; He, Yao; Huang, Qing; Fan, Chunhai

    2013-01-01

    We herein present a new kind of silicon-based electrochemical sensor using a gold nanoparticles-decorated silicon wafer (AuNPs@Si) as a high-performance electrode, which is facilely prepared via in situ AuNPs growth on a silicon wafer. Particularly significantly, the resultant electrochemical sensor is efficacious for label-free DNA detection with high sensitivity due to the unique merits of the prepared silicon-based electrode. Typically, DNA at remarkably low concentrations (1–10 fM) could be readily detected without requiring additional signal-amplification procedures, which is better than or comparable to the lowest DNA concentration ever detected via well-studied signal-amplification-assisted electrochemical sensors. Moreover, the silicon-based sensor features high specificity, allowing unambiguous discrimination of single-based mismatches. We further show that real-time DNA assembly is readily monitored via recording the intensity changes of current signals due to the robust thermal stability of the silicon-based electrode. The unprecedented advantages of the silicon-based electrochemical sensor would offer new opportunities for myriad sensing applications. (paper)

  15. High temperature dielectric function of silicon, germanium and GaN

    Energy Technology Data Exchange (ETDEWEB)

    Leyer, Martin; Pristovsek, Markus; Kneissl, Michael [Technische Universitaet Berlin (Germany). Institut fuer Festkoerperphysik

    2010-07-01

    In the last few years accurate values for the optical properties of silicon, germanium and GaN at high temperatures have become important as a reference for in-situ analysis, e.g. reflectometry. Precise temperature dependent dielectric measurements are necessary for the growth of GaInP/GaInAs/Ge triple-junction solar cells and the hetero epitaxy of GaN on silicon and sapphire. We performed spectroscopic ellipsometry (SE) measurements of the dielectric function of silicon, germanium and GaN between 1.5 eV and 6.5 eV in the temperature range from 300 K to 1300 K. The Samples were deoxidized chemically or by heating. High resolution SE spectra were taken every 50 K while cooling down to room temperature. The temperature dependence of the critical energies is compared to literature. Measurements for germanium showed a shift of the E{sub 2} critical point of {proportional_to}0.1 eV toward lower energies. The reason for this behavior is a non-negligible oxide layer on the samples in the literature.

  16. Advanced Packaging Technology Used in Fabricating a High-Temperature Silicon Carbide Pressure Sensor

    Science.gov (United States)

    Beheim, Glenn M.

    2003-01-01

    The development of new aircraft engines requires the measurement of pressures in hot areas such as the combustor and the final stages of the compressor. The needs of the aircraft engine industry are not fully met by commercially available high-temperature pressure sensors, which are fabricated using silicon. Kulite Semiconductor Products and the NASA Glenn Research Center have been working together to develop silicon carbide (SiC) pressure sensors for use at high temperatures. At temperatures above 850 F, silicon begins to lose its nearly ideal elastic properties, so the output of a silicon pressure sensor will drift. SiC, however, maintains its nearly ideal mechanical properties to extremely high temperatures. Given a suitable sensor material, a key to the development of a practical high-temperature pressure sensor is the package. A SiC pressure sensor capable of operating at 930 F was fabricated using a newly developed package. The durability of this sensor was demonstrated in an on-engine test. The SiC pressure sensor uses a SiC diaphragm, which is fabricated using deep reactive ion etching. SiC strain gauges on the surface of the diaphragm sense the pressure difference across the diaphragm. Conventionally, the SiC chip is mounted to the package with the strain gauges outward, which exposes the sensitive metal contacts on the chip to the hostile measurement environment. In the new Kulite leadless package, the SiC chip is flipped over so that the metal contacts are protected from oxidation by a hermetic seal around the perimeter of the chip. In the leadless package, a conductive glass provides the electrical connection between the pins of the package and the chip, which eliminates the fragile gold wires used previously. The durability of the leadless SiC pressure sensor was demonstrated when two 930 F sensors were tested in the combustor of a Pratt & Whitney PW4000 series engine. Since the gas temperatures in these locations reach 1200 to 1300 F, the sensors were

  17. Measurement of the drift velocities of electrons and holes in high-ohmic silicon

    International Nuclear Information System (INIS)

    Scharf, Christian

    2014-02-01

    Measurements of the drift velocities of electrons and holes as a function of the electric field and the temperature in high-ohmic silicon of crystal orientation are presented. Significant differences between our results and literature values are observed. A new parametrization of the mobility is introduced. Current transients of n-type pad diodes, generated by fast laser pulses, were investigated in order to determine the drift velocity of electrons and holes separately. Two diodes of high-ohmic silicon (1.5 kΩcm and 5.5 kΩcm) from different manufacturers were investigated as cross check. The drift velocities were determined at electric fields ranging from 5 kV/cm to 50 kV/cm at temperatures ranging from 233 K to 333 K. The mobility parameters were obtained by fitting a simulation of charge drift in silicon to the measurements. Using the convolution theorem the response function of the read-out circuit was determined with the Fourier transforms of the measurement and the simulation. The simulated transient current pulses with the new mobility parametrization are consistent with the measured ones for the temperature and electric field range investigated here. Additionally, the mobility results from the fit are consistent with the mobility determined using the simpler time-of-flight method in the field range where this method is applicable. However, our measurements show a difference of up to 14 % to the values by Canali et al. (1971). The difference to the mobility parametrization by Jacoboni et al. (1977) is up to 24 % while this parametrization is widely used for simulations of the direction due to the lack of data for silicon.

  18. 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.)

  19. Highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles

    Science.gov (United States)

    Huang, Yuewang; Zhao, Qiancheng; Sharac, Nicholas; Ragan, Regina; Boyraz, Ozdal

    2015-05-01

    We demonstrate the fabrication of a highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles for plasmonic enhancement. The average enhancement effect is evaluated by measuring the spectral broadening effect caused by self-phase-modulation. The nonlinear refractive index n2 was measured to be 7.0917×10-19 m2/W for a waveguide whose Wopen is 5 μm. Several waveguides at different locations on one wafer were measured in order to take the randomness of the nanoparticle distribution into consideration. The largest enhancement is measured to be as high as 10 times. Fabrication of this waveguide started with a MEMS grade photomask. By using conventional optical lithography, the wide linewidth was transferred to a wafer. Then the wafer was etched anisotropically by potassium hydroxide (KOH) to engrave trapezoidal trenches with an angle of 54.7º. Side wall roughness was mitigated by KOH etching and thermal oxidation that was used to generate a buffer layer for silicon nitride waveguide. The guiding material silicon nitride was then deposited by low pressure chemical vapor deposition. The waveguide was then patterned with a chemical template, with 20 nm gold particles being chemically attached to the functionalized poly(methyl methacrylate) domains. Since the particles attached only to the PMMA domains, they were confined to localized regions, therefore forcing the nanoparticles into clusters of various numbers and geometries. Experiments reveal that the waveguide has negligible nonlinear absorption loss, and its nonlinear refractive index can be greatly enhanced by gold nano clusters. The silicon nitride trench waveguide has large nonlinear refractive index, rendering itself promising for nonlinear applications.

  20. Silicon-Polymer Encapsulation of High-Level Calcine Waste for Transportation or Disposal

    International Nuclear Information System (INIS)

    Loomis, G.G.; Miller, C.M.; Giansiracusa, J.A.; Kimmel, R.; Prewett, S.V.

    2000-01-01

    This report presents the results of an experimental study investigating the potential uses for silicon-polymer encapsulation of High Level Calcine Waste currently stored within the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The study investigated two different applications of silicon polymer encapsulation. One application uses silicon polymer to produce a waste form suitable for disposal at a High Level Radioactive Waste Disposal Facility directly, and the other application encapsulates the calcine material for transportation to an offsite melter for further processing. A simulated waste material from INTEC, called pilot scale calcine, which contained hazardous materials but no radioactive isotopes was used for the study, which was performed at the University of Akron under special arrangement with Orbit Technologies, the originators of the silicon polymer process called Polymer Encapsulation Technology (PET). This document first discusses the PET process, followed by a presentation of past studies involving PET applications to waste problems. Next, the results of an experimental study are presented on encapsulation of the INTEC calcine waste as it applies to transportation or disposal of calcine waste. Results relating to long-term disposal include: (1) a characterization of the pilot calcine waste; (2) Toxicity Characteristic Leaching Procedure (TCLP) testing of an optimum mixture of pilot calcine, polysiloxane and special additives; and, (3) Material Characterization Center testing MCC-1P evaluation of the optimum waste form. Results relating to transportation of the calcine material for a mixture of maximum waste loading include: compressive strength testing, 10-m drop test, melt testing, and a Department of Transportation (DOT) oxidizer test

  1. Effect of thermal annealing on the optical and structural properties of silicon implanted with a high hydrogen fluence

    International Nuclear Information System (INIS)

    Kling, A.; Soares, J.C.; Rodriguez, A.; Rodriguez, T.; Avella, M.; Jimenez, J.

    2006-01-01

    Silicon capped by thermal oxide has been implanted with 1 x 10 17 H/cm 2 and the implant profile peaking at the interface. Samples were subjected to thermal annealing and characterized by ERD, FTIR, RBS/channeling, UV/VIS reflectance and cathodoluminescence regarding H-content, crystalline quality and light emission. The results show that the luminescent properties are independent of the hydrogen content but are strongly related with the present damage

  2. Influence for high intensity irradiation on characteristics of silicon strip-detectors

    International Nuclear Information System (INIS)

    Anokhin, I.E.; Pugatch, V.M.; Zinets, O.S.

    1995-01-01

    Full text: Silicon strip detectors (SSD) are widely used for the coordinate determination of short-range as well as minimum ionizing particles with high spatial resolution. Submicron position sensitivity of strip-detectors for short-range particles has been studied by means of two dimensional analyses of charges collected by neighboring strips as well as by measurement of charge collection times [1]. Silicon strip detectors was also used for testing high energy electron beam [2]. Under large fluences the radiation defects are stored and such characteristics of strip-detectors as an accuracy of the coordinate determination and the registration efficiency are significantly changed. Radiation defects lead to a decrease of the lifetime and mobility of charge carriers and therefore to changes of conditions for the charge collection in detectors. The inhomogeneity in spatial distribution if defects and electrical field plays an important role in the charge collection. In this report the role of the diffusion and drift in the charge collection in silicon strip-detectors under irradiation up to 10 Mrad has been studied. The electric field distribution and its dependence on the radiation dose in the detector have been calculated. It is shown that for particles incident between adjacent strips the coordinate determination precision depends strongly on the detector geometry and the electric field distribution, particularly in the vicinity of strips. Measuring simultaneously the collected charges and collection times on adjacent strips one can essentially improve reliability of the coordinate determination for short-range particles. Usually SSD are fabricated on n-type wafers. It is well known that under high intensity irradiation n-Si material converts into p-Si as far as p-type silicon is more radiative hard than n-type silicon [3] it is reasonable to fabricate SSD using high resistivity p-Si. Characteristics of SSD in basis n-and P-Si have been compared and higher

  3. An objective method for High Dynamic Range source content selection

    DEFF Research Database (Denmark)

    Narwaria, Manish; Mantel, Claire; Da Silva, Matthieu Perreira

    2014-01-01

    With the aim of improving the immersive experience of the end user, High Dynamic Range (HDR) imaging has been gaining popularity. Therefore, proper validation and performance benchmarking of HDR processing algorithms is a key step towards standardization and commercial deployment. A crucial...... component of such validation studies is the selection of a challenging and balanced set of source (reference) HDR content. In order to facilitate this, we present an objective method based on the premise that a more challenging HDR scene encapsulates higher contrast, and as a result will show up more...

  4. Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

    2013-01-01

    The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO 2 anatase, TiO 2 rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I corr than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO 2 , HA, and Ca 5 (PO 4 ) 2 SiO 4 . • Polarization resistance of the coating was increased by Si substitution in HA

  5. Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

    Directory of Open Access Journals (Sweden)

    Miao Tan

    2017-08-01

    Full Text Available We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i the work function of the transparent conductive oxide layer, (ii the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si interface, (iii the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H layer, and (iv the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

  6. NLTE ANALYSIS OF HIGH-RESOLUTION H -BAND SPECTRA. I. NEUTRAL SILICON

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Junbo; Shi, Jianrong; Liu, Chao [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012 (China); Pan, Kaike [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); Prieto, Carlos Allende, E-mail: sjr@bao.ac.cn [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2016-12-20

    We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si i) lines in the near-infrared (near-IR) H -band. We derived the differential Si abundances for 13 sample stars with high-resolution H -band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), as well as from optical spectra, both under local thermodynamical equilibrium (LTE) and NLTE conditions. We found that the differences between the Si abundances derived from the H -band and from optical lines for the same stars are less than 0.1 dex when the NLTE effects are included, and that NLTE reduces the line-to-line scatter in the H -band spectra for most sample stars. These results suggest that our Si atomic model is appropriate for studying the formation of H -band Si lines. Our calculations show that the NLTE corrections of the Si i H -band lines are negative, i.e., the final Si abundances will be overestimated in LTE. The corrections for strong lines depend on surface gravity, and tend to be larger for giants, reaching ∼−0.2 dex in our sample, and up to ∼−0.4 dex in extreme cases of APOGEE targets. Thus, the NLTE effects should be included in deriving silicon abundances from H -band Si i lines, especially for the cases where only strong lines are available.

  7. Fabrication of silicon-embedded low resistance high-aspect ratio planar copper microcoils

    Science.gov (United States)

    Syed Mohammed, Zishan Ali; Puiu, Poenar Daniel; Aditya, Sheel

    2018-01-01

    Low resistance is an important requirement for microcoils which act as a signal receiver to ensure low thermal noise during signal detection. High-aspect ratio (HAR) planar microcoils entrenched in blind silicon trenches have features that make them more attractive than their traditional counterparts employing electroplating through a patterned thick polymer or achieved through silicon vias. However, challenges met in fabrication of such coils have not been discussed in detail until now. This paper reports the realization of such HAR microcoils embedded in Si blind trenches, fabricated with a single lithography step by first etching blind trenches in the silicon substrate with an aspect ratio of almost 3∶1 and then filling them up using copper electroplating. The electroplating was followed by chemical wet etching as a faster way of removing excess copper than traditional chemical mechanical polishing. Electrical resistance was further reduced by annealing the microcoils. The process steps and challenges faced in the realization of such structures are reported here followed by their electrical characterization. The obtained electrical resistances are then compared with those of other similar microcoils embedded in blind vias.

  8. Spontaneous layering of porous silicon layers formed at high current densities

    Energy Technology Data Exchange (ETDEWEB)

    Parkhutik, Vitali; Curiel-Esparza, Jorge; Millan, Mari-Carmen [R and D Center MTM, Technical University of Valencia, Valencia (Spain); Albella, Jose [Institute of Materials Science (ICMM CSIC) Madrid (Spain)

    2005-06-01

    We report here a curious effect of spontaneous fracturing of the silicon layers formed in galvanostatic conditions at medium and high current densities. Instead of formation of homogeneous p-Si layer as at low currents, a stack of thin layers is formed. Each layer is nearly separated from others and possesses rather flat interfaces. The effects is observed using p{sup +}-Si wafers for the p-Si formation and starts being noticeable at above 100 mA/cm{sup 2}. We interpret these results in terms of the porous silicon growth model where generation of dynamic mechanical stress during the p-Si growth causes sharp changes in Si dissolution mechanism from anisotropic etching of individual needle-like pores in silicon to their branching and isotropic etching. At this moment p-Si layer loses its adhesion to the surface of Si wafer and another p-Si layer starts growing. One of the mechanisms triggering on the separation of p-Si layers from one another is a fluctuation of local anodic current in the pore bottoms associated with gas bubble evolution during the p-Si formation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Ultraviolet Plasmonic Aluminium Nanoparticles for Highly Efficient Light Incoupling on Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Yinan Zhang

    2016-05-01

    Full Text Available Plasmonic metal nanoparticles supporting localized surface plasmon resonances have attracted a great deal of interest in boosting the light absorption in solar cells. Among the various plasmonic materials, the aluminium nanoparticles recently have become a rising star due to their unique ultraviolet plasmonic resonances, low cost, earth-abundance and high compatibility with the complementary metal-oxide semiconductor (CMOS manufacturing process. Here, we report some key factors that determine the light incoupling of aluminium nanoparticles located on the front side of silicon solar cells. We first numerically study the scattering and absorption properties of the aluminium nanoparticles and the influence of the nanoparticle shape, size, surface coverage and the spacing layer on the light incoupling using the finite difference time domain method. Then, we experimentally integrate 100-nm aluminium nanoparticles on the front side of silicon solar cells with varying silicon nitride thicknesses. This study provides the fundamental insights for designing aluminium nanoparticle-based light trapping on solar cells.

  10. Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

    Science.gov (United States)

    Tan, Miao; Zhong, Sihua; Wang, Wenjie; Shen, Wenzhong

    2017-08-01

    We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H) solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i) the work function of the transparent conductive oxide layer, (ii) the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) interface, (iii) the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H) layer, and (iv) the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT) counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

  11. Highly efficient luminescent solar concentrators based on earth-abundant indirect-bandgap silicon quantum dots

    Science.gov (United States)

    Meinardi, Francesco; Ehrenberg, Samantha; Dhamo, Lorena; Carulli, Francesco; Mauri, Michele; Bruni, Francesco; Simonutti, Roberto; Kortshagen, Uwe; Brovelli, Sergio

    2017-02-01

    Building-integrated photovoltaics is gaining consensus as a renewable energy technology for producing electricity at the point of use. Luminescent solar concentrators (LSCs) could extend architectural integration to the urban environment by realizing electrode-less photovoltaic windows. Crucial for large-area LSCs is the suppression of reabsorption losses, which requires emitters with negligible overlap between their absorption and emission spectra. Here, we demonstrate the use of indirect-bandgap semiconductor nanostructures such as highly emissive silicon quantum dots. Silicon is non-toxic, low-cost and ultra-earth-abundant, which avoids the limitations to the industrial scaling of quantum dots composed of low-abundance elements. Suppressed reabsorption and scattering losses lead to nearly ideal LSCs with an optical efficiency of η = 2.85%, matching state-of-the-art semi-transparent LSCs. Monte Carlo simulations indicate that optimized silicon quantum dot LSCs have a clear path to η > 5% for 1 m2 devices. We are finally able to realize flexible LSCs with performances comparable to those of flat concentrators, which opens the way to a new design freedom for building-integrated photovoltaics elements.

  12. A new soft dielectric silicone elastomer matrix with high mechanical integrity and low losses

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede

    2015-01-01

    Though dielectric elastomers (DEs) have many favourable properties, the issue of high driving voltages limits the commercial viability of the technology. Driving voltage can be lowered by decreasing the Young's modulus and increasing the dielectric permittivity of silicone elastomers. A decrease...... in Young's modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE. A new soft elastomer matrix, with no loss of mechanical stability and high dielectric permittivity, was prepared through the use of alkyl chloride-functional siloxane copolymers...

  13. Silicon photonic transceiver circuit for high-speed polarization-based discrete variable quantum key distribution.

    Science.gov (United States)

    Cai, Hong; Long, Christopher M; DeRose, Christopher T; Boynton, Nicholas; Urayama, Junji; Camacho, Ryan; Pomerene, Andrew; Starbuck, Andrew L; Trotter, Douglas C; Davids, Paul S; Lentine, Anthony L

    2017-05-29

    We demonstrate a silicon photonic transceiver circuit for high-speed discrete variable quantum key distribution that employs a common structure for transmit and receive functions. The device is intended for use in polarization-based quantum cryptographic protocols, such as BB84. Our characterization indicates that the circuit can generate the four BB84 states (TE/TM/45°/135° linear polarizations) with >30 dB polarization extinction ratios and gigabit per second modulation speed, and is capable of decoding any polarization bases differing by 90° with high extinction ratios.

  14. Ultra-high Q terahertz whispering-gallery modes in a silicon resonator

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2018-05-01

    We report on the first experimental demonstration of terahertz (THz) whispering-gallery modes (WGMs) with an ultra-high quality factor of 1.5 × 104 at 0.62 THz. The WGMs are observed in a high resistivity float zone silicon spherical resonator coupled to a sub-wavelength silica waveguide. A detailed analysis of the coherent continuous wave THz spectroscopy measurements combined with a numerical model based on Mie-Debye-Aden-Kerker theory allows us to unambiguously identify the observed higher order radial THz WGMs.

  15. Ultra-high speed all-optical signal processing using silicon waveguides and a carbon nanotubes based mode-locked laser

    DEFF Research Database (Denmark)

    Ji, Hua

    This thesis concerns the use of nano-engineered silicon waveguides for ultra-high speed optical serial data signal processing. The fundamental nonlinear properties of nano-engineered silicon waveguides are characterized. Utilizing the nonlinear effect in nano-engineered silicon waveguides for dem...

  16. SCC with high volume of fly ash content

    Directory of Open Access Journals (Sweden)

    Bakhrakh Anton

    2017-01-01

    Full Text Available Self-compacting concrete is a very perspective building material. It provides great benefits during the construction of heavily reinforced buildings. SCC has outstanding properties such as high flowability, dense structure and high strength due to specific quality of aggregates, fillers, their proportion in mix, use of polycarboxylate-based superplasticizers. Main disadvantages of SCC are high price and the difficulty of obtaining a proper mix. Use of fillers, such as fly ash type F, is a way to make SCC cheaper by replacing part of cement. Fly ash also provides some technological and operating advantages. In this paper the influence of high volume (60% from cement fly ash type F on the properties of concrete mixture and hardened concrete is investigated. The result of the work shows the possibility of reduction the cost of SCC using ordinary fillers and high amount of fly ash. The investigated SCC has low speed of hardening (7-day compressive strength at the range of 41.8 MPa and high volume of entrained air content (3.5%.

  17. Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

    KAUST Repository

    Rojas, Jhonathan Prieto

    2013-01-07

    Can we build a flexible and transparent truly high performance computer? High-k/metal gate stack based metal-oxide-semiconductor capacitor devices are monolithically fabricated on industry\\'s most widely used low-cost bulk single-crystalline silicon (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree of freedom to fabricate nanoelectronics devices using state-of-the-art CMOS compatible processes and then to utilize them in an unprecedented way for wide deployment over nearly any kind of shape and architecture surfaces. Electrical characterization shows uncompromising performance of post release devices. Mechanical characterization shows extra-ordinary flexibility (minimum bending radius of 1 cm) making this generic process attractive to extend the horizon of flexible electronics for truly high performance computers. Schematic and photograph of flexible high-k/metal gate MOSCAPs showing high flexibility and C-V plot showing uncompromised performance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Mesoporous Silicon Sponge as an Anti-Pulverization Structure for High-Performance Lithium-ion Battery Anodes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaolin; Gu, Meng; Hu, Shenyang Y.; Kennard, Rhiannon; Yan, Pengfei; Chen, Xilin; Wang, Chong M.; Sailor, Michael J.; Zhang, Jiguang; Liu, Jun

    2014-07-08

    Nanostructured silicon is a promising anode material for high performance lithium-ion batteries, yet scalable synthesis of such materials, and retaining good cycling stability in high loading electrode remain significant challenges. Here, we combine in-situ transmission electron microscopy and continuum media mechanical calculations to demonstrate that large (>20 micron) mesoporous silicon sponge (MSS) prepared by the scalable anodization method can eliminate the pulverization of the conventional bulk silicon and limit particle volume expansion at full lithiation to ~30% instead of ~300% as observed in bulk silicon particles. The MSS can deliver a capacity of ~750 mAh/g based on the total electrode weight with >80% capacity retention over 1000 cycles. The first-cycle irreversible capacity loss of pre-lithiated MSS based anode is only <5%. The insight obtained from MSS also provides guidance for the design of other materials that may experience large volume variation during operations.

  19. Real-Time and In-Flow Sensing Using a High Sensitivity Porous Silicon Microcavity-Based Sensor

    Directory of Open Access Journals (Sweden)

    Raffaele Caroselli

    2017-12-01

    Full Text Available Porous silicon seems to be an appropriate material platform for the development of high-sensitivity and low-cost optical sensors, as their porous nature increases the interaction with the target substances, and their fabrication process is very simple and inexpensive. In this paper, we present the experimental development of a porous silicon microcavity sensor and its use for real-time in-flow sensing application. A high-sensitivity configuration was designed and then fabricated, by electrochemically etching a silicon wafer. Refractive index sensing experiments were realized by flowing several dilutions with decreasing refractive indices, and measuring the spectral shift in real-time. The porous silicon microcavity sensor showed a very linear response over a wide refractive index range, with a sensitivity around 1000 nm/refractive index unit (RIU, which allowed us to directly detect refractive index variations in the 10−7 RIU range.

  20. Modelling of diffusion in presurface silicon layer under the action of pulsed high-intensity ion beam

    International Nuclear Information System (INIS)

    Aktaev, N.E.; Remnev, G.E.

    2015-01-01

    The influence of the pulsed high-intensity ion beam on the silicon is studied by use the developed theoretical model. The input parameters of the model were the settings of the experimental setup of the TEMP-4. It is shown, that at the short-pulsed implantation regime of the TEMP-4 the silicon surface does not melt. However, the regime leads to the high temperature gradient which promotes the diffusion process from the surface into the depth the silicon simple. The diffused particles are the carbon atoms adsorbed on the silicon surface by the various cases. Thus, it is shown that the carbon atom diffused from the surface make the main contribution to the forming of the concentration profile. The concentration of the implanted carbon ions less more than tree orders compared with the concentration of the diffused carbon atoms. (authors)

  1. Real-Time and In-Flow Sensing Using a High Sensitivity Porous Silicon Microcavity-Based Sensor.

    Science.gov (United States)

    Caroselli, Raffaele; Martín Sánchez, David; Ponce Alcántara, Salvador; Prats Quilez, Francisco; Torrijos Morán, Luis; García-Rupérez, Jaime

    2017-12-05

    Porous silicon seems to be an appropriate material platform for the development of high-sensitivity and low-cost optical sensors, as their porous nature increases the interaction with the target substances, and their fabrication process is very simple and inexpensive. In this paper, we present the experimental development of a porous silicon microcavity sensor and its use for real-time in-flow sensing application. A high-sensitivity configuration was designed and then fabricated, by electrochemically etching a silicon wafer. Refractive index sensing experiments were realized by flowing several dilutions with decreasing refractive indices, and measuring the spectral shift in real-time. The porous silicon microcavity sensor showed a very linear response over a wide refractive index range, with a sensitivity around 1000 nm/refractive index unit (RIU), which allowed us to directly detect refractive index variations in the 10 -7 RIU range.

  2. Modeling the high-frequency complex modulus of silicone rubber using standing Lamb waves and an inverse finite element method.

    Science.gov (United States)

    Jonsson, Ulf; Lindahl, Olof; Andersson, Britt

    2014-12-01

    To gain an understanding of the high-frequency elastic properties of silicone rubber, a finite element model of a cylindrical piezoelectric element, in contact with a silicone rubber disk, was constructed. The frequency-dependent elastic modulus of the silicone rubber was modeled by a fourparameter fractional derivative viscoelastic model in the 100 to 250 kHz frequency range. The calculations were carried out in the range of the first radial resonance frequency of the sensor. At the resonance, the hyperelastic effect of the silicone rubber was modeled by a hyperelastic compensating function. The calculated response was matched to the measured response by using the transitional peaks in the impedance spectrum that originates from the switching of standing Lamb wave modes in the silicone rubber. To validate the results, the impedance responses of three 5-mm-thick silicone rubber disks, with different radial lengths, were measured. The calculated and measured transitional frequencies have been compared in detail. The comparison showed very good agreement, with average relative differences of 0.7%, 0.6%, and 0.7% for the silicone rubber samples with radial lengths of 38.0, 21.4, and 11.0 mm, respectively. The average complex elastic moduli of the samples were (0.97 + 0.009i) GPa at 100 kHz and (0.97 + 0.005i) GPa at 250 kHz.

  3. A content analysis of tweets about high-potency marijuana.

    Science.gov (United States)

    Cavazos-Rehg, Patricia A; Sowles, Shaina J; Krauss, Melissa J; Agbonavbare, Vivian; Grucza, Richard; Bierut, Laura

    2016-09-01

    "Dabbing" involves heating extremely concentrated forms of marijuana to high temperatures and inhaling the resulting vapor. We studied themes describing the consequences of using highly concentrated marijuana by examining the dabbing-related content on Twitter. Tweets containing dabbing-related keywords were collected from 1/1-1/31/2015 (n=206,854). A random sample of 5000 tweets was coded for content according to pre-determined categories about dabbing-related behaviors and effects experienced using a crowdsourcing service. An examination of tweets from the full sample about respiratory effects and passing out was then conducted by selecting tweets with relevant keywords. Among the 5000 randomly sampled tweets, 3540 (71%) were related to dabbing marijuana concentrates. The most common themes included mentioning current use of concentrates (n=849; 24%), the intense high and/or extreme effects from dabbing (n=763; 22%) and excessive/heavy dabbing (n=517; 15%). Extreme effects included both physiological (n=124/333; 37%) and psychological effects (n=55/333; 17%). The most common physiologic effects, passing out (n=46/333; 14%) and respiratory effects (n=30/333; 9%), were then further studied in the full sample of tweets. Coughing was the most common respiratory effect mentioned (n=807/1179; 68%), and tweeters commonly expressed dabbing with intentions to pass out (416/915; 45%). This study adds to the limited understanding of marijuana concentrates and highlights self-reported physical and psychological effects from this type of marijuana use. Future research should further examine these effects and the potential severity of health consequences associated with concentrates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. High GC content causes orphan proteins to be intrinsically disordered.

    Directory of Open Access Journals (Sweden)

    Walter Basile

    2017-03-01

    Full Text Available De novo creation of protein coding genes involves the formation of short ORFs from noncoding regions; some of these ORFs might then become fixed in the population. These orphan proteins need to, at the bare minimum, not cause serious harm to the organism, meaning that they should for instance not aggregate. Therefore, although the creation of short ORFs could be truly random, the fixation should be subjected to some selective pressure. The selective forces acting on orphan proteins have been elusive, and contradictory results have been reported. In Drosophila young proteins are more disordered than ancient ones, while the opposite trend is present in yeast. To the best of our knowledge no valid explanation for this difference has been proposed. To solve this riddle we studied structural properties and age of proteins in 187 eukaryotic organisms. We find that, with the exception of length, there are only small differences in the properties between proteins of different ages. However, when we take the GC content into account we noted that it could explain the opposite trends observed for orphans in yeast (low GC and Drosophila (high GC. GC content is correlated with codons coding for disorder promoting amino acids. This leads us to propose that intrinsic disorder is not a strong determining factor for fixation of orphan proteins. Instead these proteins largely resemble random proteins given a particular GC level. During evolution the properties of a protein change faster than the GC level causing the relationship between disorder and GC to gradually weaken.

  5. Production of JET fuel containing molecules of high hydrogen content

    Directory of Open Access Journals (Sweden)

    Tomasek Sz.

    2017-12-01

    Full Text Available The harmful effects of aviation can only be reduced by using alternative fuels with excellent burning properties and a high hydrogen content in the constituent molecules. Due to increasing plastic consumption the amount of the plastic waste is also higher. Despite the fact that landfill plastic waste has been steadily reduced, the present scenario is not satisfactory. Therefore, the aim of this study is to produce JET fuel containing an alternative component made from straight-run kerosene and the waste polyethylene cracking fraction. We carried out our experiments on a commercial NiMo/Al2O3/P catalyst at the following process parameters: T=200-300°C, P=40 bar, LHSV=1.0-3.0 h-1, hydrogen/hydrocarbon ratio= 400 Nm3/m3. We investigated the effects of the feedstocks and the process parameters on the product yields, the hydrodesulfurization and hydrodearomatization efficiencies, and the main product properties. The liquid product yields varied between 99.7-99.8%. As a result of the hydrogenation the sulfur (1-1780 mg/kg and the aromatic contents (9.0-20.5% of the obtained products and the values of their smoke points (26.0-34.7 mm fulfilled the requirements of JET fuel standard. Additionally, the concentration of paraffins increased in the products and the burning properties were also improved. The freezing points of the products were higher than -47°C, therefore product blending is needed.

  6. Subsurface damage mechanism of high speed grinding process in single crystal silicon revealed by atomistic simulations

    International Nuclear Information System (INIS)

    Li, Jia; Fang, Qihong; Zhang, Liangchi; Liu, Youwen

    2015-01-01

    Highlights: • Molecular dynamic model of nanoscale high speed grinding of silicon workpiece has been established. • The effect of grinding speed on subsurface damage and grinding surface integrity by analyzing the chip, dislocation movement, and phase transformation during high speed grinding process are thoroughly investigated. • Subsurface damage is studied by the evolution of surface area at first time for more obvious observation on transition from ductile to brittle. • The hydrostatic stress and von Mises stress by the established analytical model are studied subsurface damage mechanism during nanoscale grinding. - Abstract: Three-dimensional molecular dynamics (MD) simulations are performed to investigate the nanoscale grinding process of single crystal silicon using diamond tool. The effect of grinding speed on subsurface damage and grinding surface integrity by analyzing the chip, dislocation movement, and phase transformation are studied. We also establish an analytical model to calculate several important stress fields including hydrostatic stress and von Mises stress for studying subsurface damage mechanism, and obtain the dislocation density on the grinding subsurface. The results show that a higher grinding velocity in machining brittle material silicon causes a larger chip and a higher temperature, and reduces subsurface damage. However, when grinding velocity is above 180 m s −1 , subsurface damage thickness slightly increases because a higher grinding speed leads to the increase in grinding force and temperature, which accelerate dislocation nucleation and motion. Subsurface damage is studied by the evolution of surface area at first time for more obvious observation on transition from ductile to brittle, that provides valuable reference for machining nanometer devices. The von Mises stress and the hydrostatic stress play an important role in the grinding process, and explain the subsurface damage though dislocation mechanism under high

  7. Scalable Upcycling Silicon from Waste Slicing Sludge for High-performance Lithium-ion Battery Anodes

    International Nuclear Information System (INIS)

    Bao, Qi; Huang, Yao-Hui; Lan, Chun-Kai; Chen, Bing-Hong; Duh, Jenq-Gong

    2015-01-01

    Silicon (Si) has been perceived as a promising next-generation anode material for lithium ion batteries (LIBs) due to its superior theoretical capacity. Despite the natural abundance of this element on Earth, large-scale production of high-purity Si nanomaterials in a green and energy-efficient way is yet to become an industrial reality. Spray-drying methods have been exploited to recover Si particles from low-value sludge produced in the photovoltaic industry, providing a massive and cost-effective Si resource for fabricating anode materials. To address such drawbacks like volume expansion, low electrical and Li + conductivity and unstable solid electrolyte interphase (SEI) formation, the recycled silicon particles have been downsized into nanoscale and shielded by a highly conductive and protective graphene multilayer through high energy ball milling. Cyclic voltammetry and electrochemical impedance spectroscopy measurements have revealed that the graphene wrapping and size reduction approach have significantly improved the electrochemical performance. It delivers an excellent reversible capacity of 1,138 mA h g −1 and a long cycle life with 73% capacity retention over 150 cycles at a high current of 450 mA g −1 . The plentiful waste conversion methodology also provides considerable opportunities for developing additional rechargeable devices, ceramic, powder metallurgy and silane/siloxane products

  8. Large-area hexagonal silicon detectors for the CMS High Granularity Calorimeter

    Science.gov (United States)

    Pree, E.

    2018-02-01

    During the so-called Phase-2 Upgrade, the CMS experiment at CERN will undergo significant improvements to cope with the 10-fold luminosity increase of the High Luminosity LHC (HL-LHC) era. Especially the forward calorimetry will suffer from very high radiation levels and intensified pileup in the detectors. For this reason, the CMS collaboration is designing a High Granularity Calorimeter (HGCAL) to replace the existing endcap calorimeters. It features unprecedented transverse and longitudinal segmentation for both electromagnetic (CE-E) and hadronic (CE-H) compartments. The CE-E and a large fraction of CE-H will consist of a sandwich structure with silicon as active detector material. This paper presents an overview of the ongoing sensor development for the HGCAL and highlights important design features and measurement techniques. The design and layout of an 8-inch silicon sensor prototype is shown. The hexagonal sensors consist of 235 pads, each with an area of about 1 cm2. Furthermore, Synopsys TCAD simulations regarding the high voltage stability of the sensors for different geometric parameters are performed. Finally, two different IV characterisation methods are compared on the same sensor.

  9. Design, development and tests of high-performance silicon vapor chamber

    International Nuclear Information System (INIS)

    Cai, Qingjun; Chen, Bing-chung; Tsai, Chialun

    2012-01-01

    This paper presents a novel triple stack process to develop an all-silicon thermal ground plane (TGP) vapor chamber that enables fabrication of compact, large scale, low thermal expansion coefficient mismatch and high-performance heat transfer devices. The TGP vapor chamber is formed through bonding three etched silicon wafers. On both the top and bottom wafers, microscale and high aspect ratio wick structures are etched for liquid transport. The 1.5 mm thick middle layer contains the cavities for vapor flow. To achieve hermetic seal, glass frit with four sealing rings, approximately 300 µm wide and 30 µm thick, is used to bond the edges and supporting posts. For experimental evaluations, 3 mm × 38 mm × 38 mm TGP vapor chambers are developed. The volume density of the heat transfer device is approximately 1.5 × 10 3 kg m −3 . Measurement of mass loss and stability studies of heat transfer indicates that the vapor chamber system is hermetically sealed. Using ethanol as the operating liquid, high heat transfer performance is demonstrated. Effective thermal conductivity reaches over 2500 W m −1  ⋅ K −1 . Under high g environment, experimental results show good liquid transport capabilities of the wick structures. (paper)

  10. Design, development and tests of high-performance silicon vapor chamber

    Science.gov (United States)

    Cai, Qingjun; Chen, Bing-chung; Tsai, Chialun

    2012-03-01

    This paper presents a novel triple stack process to develop an all-silicon thermal ground plane (TGP) vapor chamber that enables fabrication of compact, large scale, low thermal expansion coefficient mismatch and high-performance heat transfer devices. The TGP vapor chamber is formed through bonding three etched silicon wafers. On both the top and bottom wafers, microscale and high aspect ratio wick structures are etched for liquid transport. The 1.5 mm thick middle layer contains the cavities for vapor flow. To achieve hermetic seal, glass frit with four sealing rings, approximately 300 µm wide and 30 µm thick, is used to bond the edges and supporting posts. For experimental evaluations, 3 mm × 38 mm × 38 mm TGP vapor chambers are developed. The volume density of the heat transfer device is approximately 1.5 × 103 kg m-3. Measurement of mass loss and stability studies of heat transfer indicates that the vapor chamber system is hermetically sealed. Using ethanol as the operating liquid, high heat transfer performance is demonstrated. Effective thermal conductivity reaches over 2500 W m-1 ṡ K-1. Under high g environment, experimental results show good liquid transport capabilities of the wick structures.

  11. Annealing temperature dependence of photoluminescent characteristics of silicon nanocrystals embedded in silicon-rich silicon nitride films grown by PECVD

    International Nuclear Information System (INIS)

    Chao, D.S.; Liang, J.H.

    2013-01-01

    Recently, light emission from silicon nanostructures has gained great interest due to its promising potential of realizing silicon-based optoelectronic applications. In this study, luminescent silicon nanocrystals (Si–NCs) were in situ synthesized in silicon-rich silicon nitride (SRSN) films grown by plasma-enhanced chemical vapor deposition (PECVD). SRSN films with various excess silicon contents were deposited by adjusting SiH 4 flow rate to 100 and 200 sccm and keeping NH 3 one at 40 sccm, and followed by furnace annealing (FA) treatments at 600, 850 and 1100 °C for 1 h. The effects of excess silicon content and post-annealing temperature on optical properties of Si–NCs were investigated by photoluminescence (PL) and Fourier transform infrared spectroscopy (FTIR). The origins of two groups of PL peaks found in this study can be attributed to defect-related interface states and quantum confinement effects (QCE). Defect-related interface states lead to the photon energy levels almost kept constant at about 3.4 eV, while QCE results in visible and tunable PL emission in the spectral range of yellow and blue light which depends on excess silicon content and post-annealing temperature. In addition, PL intensity was also demonstrated to be highly correlative to the excess silicon content and post-annealing temperature due to its corresponding effects on size, density, crystallinity, and surface passivation of Si–NCs. Considering the trade-off between surface passivation and structural properties of Si–NCs, an optimal post-annealing temperature of 600 °C was suggested to maximize the PL intensity of the SRSN films

  12. Cermet anode compositions with high content alloy phase

    Science.gov (United States)

    Marschman, Steven C.; Davis, Norman C.

    1989-01-01

    Cermet electrode compositions comprising NiO-NiFe.sub.2 O.sub.4 -Cu-Ni, and methods for making, are disclosed. Addition of nickel metal prior to formation and densification of a base mixture into the cermet allows for an increase in the total amount of copper and nickel that can be contained in the NiO-NiFe.sub.2 O.sub.4 oxide system. Nickel is present in a base mixture weight concentration of from 0.1% to 10%. Copper is present in the alloy phase in a weight concentration of from 10% to 30% of the densified composition. Such cermet electrodes can be formed to have electrical conductivities well in excess of 100 ohm.sup.-1 cm.sup.-1. Other alloy and oxide system cermets having high content metal phases are also expected to be manufacturable in accordance with the invention.

  13. Automation in high-content flow cytometry screening.

    Science.gov (United States)

    Naumann, U; Wand, M P

    2009-09-01

    High-content flow cytometric screening (FC-HCS) is a 21st Century technology that combines robotic fluid handling, flow cytometric instrumentation, and bioinformatics software, so that relatively large numbers of flow cytometric samples can be processed and analysed in a short period of time. We revisit a recent application of FC-HCS to the problem of cellular signature definition for acute graft-versus-host-disease. Our focus is on automation of the data processing steps using recent advances in statistical methodology. We demonstrate that effective results, on par with those obtained via manual processing, can be achieved using our automatic techniques. Such automation of FC-HCS has the potential to drastically improve diagnosis and biomarker identification.

  14. Diffusion in a pure, high-vacancy-content crystal

    International Nuclear Information System (INIS)

    McKee, R.A.

    1981-01-01

    The idea that vacancies can follow a nonrandom walk in a solid has been developed and put into a quantitative form for diffusion in a pure, high-vacancy-content crystal. Intrinsic and tracer diffusion in a metal have been analyzed, and the electrical mobility in an ionic solid has been expressed in terms of the tracer diffusion coefficient and the separate correlation factors for atoms and vacancies. The description uses classical methods of diffusion theory, and generalized results that account for nonrandom vacancy walk have been shown to reduce to those obtained by Howard and Lidiard in a system where the vacancy moves randomly as an isolated point defect. Experimental data for carbon diffusion in fcc iron have been examined to illustrate an interstitial-vacancy analogy that was used in this analysis, and the general result has been applied specifically to discuss vacancy diffusion in Fe/sub 1-x/S

  15. Large Size High Performance Transparent Amorphous Silicon Sensors for Laser Beam Position Detection and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A.; Martinez Rivero, C.; Matorras, F.; Rodrigo, T.; Sobron, M.; Vila, I.; Virto; Alberdi, J.; Arce, P.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Luque, J. M.; Molinero, A.; Navarrete, J.; Oller, J. C.; Kohler, C.; Lutz, B.; Schubert, M. B.

    2006-09-04

    We present the measured performance of a new generation of semitransparente amorphous silicon position detectors. They have a large sensitive area (30 x 30 mm2) and show good properties such as a high response (about 20 mA/W), an intinsic position resolution better than 3 m, a spatial point reconstruction precision better than 10 m, deflection angles smaller than 10 rad and a transmission power in the visible and NIR higher than 70%. In addition, multipoint alignment monitoring, using up to five sensors lined along a light path of about 5 meters, can be achieved with a resolution better than 20m. (Author)

  16. High-Efficiency Volume Reflection of an Ultrarelativistic Proton Beam with a Bent Silicon Crystal

    CERN Document Server

    Scandale, Walter; Carnera, Alberto; Della Mea, Gianantonio; De Salvador, Davide; Milan, Riccardo; Vomiero, Alberto; Baricordi, Stefano; Dalpiaz, Pietro; Fiorini, Massimiliano; Guidi, Vincenzo; Martinelli,Giuliano; Mazzolari, Andrea; Milan, Emiliano; Ambrosi, Giovanni; Azzarello, Philipp; Battiston, Roberto; Bertucci, Bruna; Burger, William J; Ionica, Maria; Zuccon, Paolo; Cavoto, Gianluca; Santacesaria, Roberta; Valente, Paolo; Vallazza, Erik; Afonin, Alexander G; Baranov, Vladimir T; Chesnokov, Yury A; Kotov, Vladilen I; Maisheev, Vladimir A; Yaznin, Igor A; Afansiev, Sergey V; Kovalenko, Alexander D; Taratin, Alexander M; Denisov, Alexander S; Gavrikov, Yury A; Ivanov, Yuri M; Ivochkin, Vladimir G; Kosyanenko, Sergey V; Petrunin, Anatoli A; Skorobogatov, Vyacheslav V; Suvorov, Vsevolod M; Bolognini, Davide; Foggetta,Luca; Hasan, Said; Prest, Michela

    2007-01-01

    The volume reflection phenomenon was detected while investigating 400 GeV proton interactions with bent silicon crystals in the external beam H8 of the CERN Super Proton Synchrotron. Such a process was observed for a wide interval of crystal orientations relative to the beam axis, and its efficiency exceeds 95%, thereby surpassing any previously observed value. These observations suggest new perspectives for the manipulation of high-energy beams, e.g., for collimation and extraction in new-generation hadron colliders, such as the CERN Large Hadron Collider.

  17. Defect characterization in high-purity silicon after γ- and hadron irradiation

    International Nuclear Information System (INIS)

    Stahl, J.

    2004-07-01

    The challenge for silicon particle detectors in future high energy physics experiments caused by extreme radiation fields can only be met by an appropriate defect engineering of the starting material. Appreciable improvements had already been obtained by enriching high resistivity float zone silicon with oxygen as demonstrated by the CERN RD48 collaboration. This thesis will focus on the difference observed after irradiation between standard and oxygenated float zone and detector grade Czochralski silicon. Results obtained with diodes manufactured on epitaxial layers are also included, envisioning effects arising from the possible migration of impurities during the crystal growth from the oxygen rich Czochralski substrate. Deep level transient spectroscopy (DLTS) and thermally stimulated current (TSC) measurements have been performed for defect characterization after γ- and hadron irradiation. Also a new high resolution DLTS technique has been used for the first time to separate defect levels with similar parameters. During the microscopic studies additionally to the well known defects like VO i , V 2 , C i O i or VP, four new radiation induced defects have been discovered and characterized. Two of these defects are closely correlated with the detector performance: A deep acceptor labeled as I-defect, and a bistable donor (BD). The formation of the I-defect is strongly suppressed in oxygen rich materials, while the formation of the BD is suppressed in oxygen lean material. With their properties the I- and the BD-defect are able to explain the different macroscopic behavior of standard and oxygen enriched float zone silicon after γ-irradiation. Furthermore, the BD defect is most probably responsible for the observation that in Cz and Epi diodes space charge sign inversion does not occur even after high fluences of proton irradiation. Additionally the γ-irradiated diodes were annealed at temperatures between 100 C and 350 C. During these studies some new reaction

  18. X-Ray diffraction studies of silicon implanted with high energy ions

    International Nuclear Information System (INIS)

    Wieteska, K.; Wierzchowski, W.; Graeff, W.

    1998-01-01

    The character of lattice deformation in silicon implanted with high energy alpha-particles and protons was studied using a number of X-ray methods. The experiments included double-crystal spectrometer method as well as single crystal section and projection topography realised both with conventional and synchrotron X-ray sources. All observed diffraction patterns were reasonably explainable assuming the lattice parameter distribution proportional to the vacancy-interstitial distribution coming from the Biersack-ziegler theory. The theoretical rocking curves and distribution in back-reflection double-crystal and section topographs well corresponding to the experimental results were calculated using numerical integration of the takagi-taupin equations

  19. Large-size high-performance transparent amorphous silicon sensors for laser beam position detection

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Martinez-Rivero, C. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Matorras, F. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Rodrigo, T. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Sobron, M. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Vila, I. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Virto, A.L. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Alberdi, J. [CIEMAT, Madrid (Spain); Arce, P. [CIEMAT, Madrid (Spain); Barcala, J.M. [CIEMAT, Madrid (Spain); Calvo, E. [CIEMAT, Madrid (Spain); Ferrando, A. [CIEMAT, Madrid (Spain)]. E-mail: antonio.ferrando@ciemat.es; Josa, M.I. [CIEMAT, Madrid (Spain); Luque, J.M. [CIEMAT, Madrid (Spain); Molinero, A. [CIEMAT, Madrid (Spain); Navarrete, J. [CIEMAT, Madrid (Spain); Oller, J.C. [CIEMAT, Madrid (Spain); Yuste, C. [CIEMAT, Madrid (Spain); Koehler, C. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Lutz, B. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Schubert, M.B. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Werner, J.H. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany)

    2006-09-15

    We present the measured performance of a new generation of semitransparent amorphous silicon position detectors. They have a large sensitive area (30x30mm{sup 2}) and show good properties such as a high response (about 20mA/W), an intrinsic position resolution better than 3{mu}m, a spatial-point reconstruction precision better than 10{mu}m, deflection angles smaller than 10{mu}rad and a transmission power in the visible and NIR higher than 70%.

  20. Analysis for silicon in solution in high level waste glass durability studies

    International Nuclear Information System (INIS)

    Lewis, R.A.; Smart, R.St.C.; Dale, L.S.; Levins, D.M.

    1982-01-01

    In comparative studies of the durability of HLW glasses, the measurement of the dissolution of the silicate network, in terms of both rate and extent, is of prime importance. To achieve this, analytical techniques such as colorimetry, flame atomic absorption spectrometry and inductively-coupled plasma emission spectrometry are used. The reliability of these analytical techniques for determination of silicon concentration in dissolution of HLW glasses, is examined. At high concentrations both FAA and ICP are accurate but colorimetry, even with HF pretreatment or NaOH digestion, does not give agreement with ICP. At concentrations below 40 mg l -1 all three methods are reliable. (Auth.)

  1. Functional test of a Radon sensor based on a high-resistivity-silicon BJT detector

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Betta, G.F., E-mail: dallabe@disi.unitn.it [DISI, Università di Trento, and INFN Trento, Trento (Italy); RSens srl, Modena (Italy); Tyzhnevyi, V. [DISI, Università di Trento, and INFN Trento, Trento (Italy); Bosi, A.; Bonaiuti, M. [RSens srl, Modena (Italy); Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Forti, F.; Giorgi, M.A.; Morsani, F.; Paoloni, E.; Rizzo, G.; Walsh, J. [Dipartimento di Fisica, Università di Pisa, and INFN Pisa, Pisa (Italy); Lusiani, A. [Scuola Normale Superiore and INFN Pisa, Pisa (Italy); Ciolini, R.; Curzio, G.; D' Errico, F.; Del Gratta, A. [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Università di Pisa, Pisa (Italy); Bidinelli, L. [En and tech, Università di Modena e Reggio Emilia, Reggio Emilia (Italy); RSens srl, Modena (Italy); and others

    2013-08-01

    A battery-powered, wireless Radon sensor has been designed and realized using a BJT, fabricated on a high-resistivity-silicon substrate, as a radiation detector. Radon daughters are electrostatically collected on the detector surface. Thanks to the BJT internal amplification, real-time α particle detection is possible using simple readout electronics, which records the particle arrival time and charge. Functional tests at known Radon concentrations, demonstrated a sensitivity up to 4.9 cph/(100 Bq/m{sup 3}) and a count rate of 0.05 cph at nominally-zero Radon concentration.

  2. Deflection of high energy channeled charged particles by elastically bent silicon single crystals

    International Nuclear Information System (INIS)

    Gibson, W.M.; Kim, I.J.; Pisharodoy, M.; Salman, S.M.; Sun, C.R.; Wang, G.H.; Wijayawardana, R.; Forster, J.S.; Mitchell, I.V.; Baker, S.I.; Carrigan, R.A. Jr.; Toohig, T.E.; Avdeichikov, V.V.; Ellison, J.A.; Siffert, P.

    1984-01-01

    An experiment has been carried out to observe the deflection of charged particles by planar channeling in bent single crystals of silicon for protons with energy up to 180 GeV. Anomolous loss of particles from the center point of a three point bending apparatus was observed at high incident particle energy. This effect has been exploited to fashion a 'dechanneling spectrometer' to study dechanneling effects due to centripital displacement of channeled particle trajectories in a bent crystal. The bending losses generally conform to the predictions of calculations based on a classical model. (orig.)

  3. Large Size High Performance Transparent Amorphous Silicon Sensors for Laser Beam Position Detection and Monitoring

    International Nuclear Information System (INIS)

    Calderon, A.; Martinez Rivero, C.; Matorras, F.; Rodrigo, T.; Sobron, M.; Vila, I.; Virto; Alberdi, J.; Arce, P.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Luque, J. M.; Molinero, A.; Navarrete, J.; Oller, J. C.; Kohler, C.; Lutz, B.; Schubert, M. B.

    2006-01-01

    We present the measured performance of a new generation of semitransparente amorphous silicon position detectors. They have a large sensitive area (30 x 30 mm2) and show good properties such as a high response (about 20 mA/W), an intinsic position resolution better than 3 m, a spatial point reconstruction precision better than 10 m, deflection angles smaller than 10 rad and a transmission power in the visible and NIR higher than 70%. In addition, multipoint alignment monitoring, using up to five sensors lined along a light path of about 5 meters, can be achieved with a resolution better than 20m. (Author)

  4. Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

    CERN Document Server

    Bilki, B.; Schlereth, J.; Xia, L.; Deng, Z.; Li, Y.; Wang, Y.; Yue, Q.; Yang, Z.; Eigen, G.; Mikami, Y.; Price, T.; Watson, N.K.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Carloganu, C.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Blazey, G.C.; Dyshkant, A.; Francis, K.; Lima, J.G.R.; Salcido, P.; Zutshi, V.; Boisvert, V.; Green, B.; Misiejuk, A.; Salvatore, F.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Suehara, T.; Tomita, T.; Ueno, H.; Yoshioka, T.; Apostolakis, J.; Folger, G.; Ivantchenko, V.; Ribon, A.; Uzhinskiy, V.; Cauwenbergh, S.; Tytgat, M.; Zaganidis, N.; Hostachy, J.Y.; Morin, L.; Gadow, K.; Göttlicher, P.; Günter, C.; Krüger, K.; Lutz, B.; Reinecke, M.; Sefkow, F.; Feege, N.; Garutti, E.; Laurien, S.; Lu, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Kaplan, A.; Norbeck, E.; Northacker, D.; Onel, Y.; Kim, E.J.; van Doren, B.; Wilson, G.W.; Wing, M.; Bobchenko, B.; Chadeeva, M.; Chistov, R.; Danilov, M.; Drutskoy, A.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Popov, V.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Popova, E.; Gabriel, M.; Kiesling, C.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Callier, S.; Conforti di Lorenzo, S.; Cornebise, P.; Doublet, Ph.; Dulucq, F.; Faucci-Giannelli, M.; Fleury, J.; Frisson, T.; Kégl, B.; van der Kolk, N.; Li, H.; Martin-Chassard, G.; Richard, F.; de la Taille, Ch.; Pöschl, R.; Raux, L.; Rouëne, J.; Seguin-Moreau, N.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J.-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Magniette, F.; Matthieu, A.; Mora de Freitas, P.; Videau, H.; Augustin, J.-E.; David, J.; Ghislain, P.; Lacour, D.; Lavergne, L.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Jeans, D.; Götze, M.

    2015-09-11

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the GEANT4 simulation tool kit are compared to this data. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  5. Highly -oriented growth of polycrystalline silicon films on glass by pulsed magnetron sputtering

    International Nuclear Information System (INIS)

    Reinig, P.; Selle, B.; Fenske, F.; Fuhs, W.; Alex, V.; Birkholz, M.

    2002-01-01

    Nominally undoped polycrystalline silicon (poly-Si) thin films were deposited on glass at 450 deg. C at high deposition rate (>100 nm/min) by pulsed dc magnetron sputtering. The pulse frequency was found to have a significant influence on the preferred grain orientation. The x-ray diffraction pattern exhibits a strong enhancement of the (400) reflex with increasing pulse frequency. The quantitative evaluation reveals that over 90% of the grains are oriented. The observed change in preferred grain orientation in poly-Si films at low temperatures is associated with concurrent ion bombardment of the growing film

  6. Silicon Carbide-Based Hydrogen Gas Sensors for High-Temperature Applications

    Directory of Open Access Journals (Sweden)

    Sangchoel Kim

    2013-10-01

    Full Text Available We investigated SiC-based hydrogen gas sensors with metal-insulator-semiconductor (MIS structure for high temperature process monitoring and leak detection applications in fields such as the automotive, chemical and petroleum industries. In this work, a thin tantalum oxide (Ta2O5 layer was exploited with the purpose of sensitivity improvement, because tantalum oxide has good stability at high temperature with high permeability for hydrogen gas. Silicon carbide (SiC was used as a substrate for high-temperature applications. We fabricated Pd/Ta2O5/SiC-based hydrogen gas sensors, and the dependence of their I-V characteristics and capacitance response properties on hydrogen concentrations were analyzed in the temperature range from room temperature to 500 °C. According to the results, our sensor shows promising performance for hydrogen gas detection at high temperatures.

  7. Inorganic Glue Enabling High Performance of Silicon Particles as Lithium Ion Battery Anode

    KAUST Repository

    Cui, Li-Feng; Hu, Liangbing; Wu, Hui; Choi, Jang Wook; Cui, Yi

    2011-01-01

    overcome the pulverization problem, however these nano-engineered silicon anodes usually involve very expensive processes and have difficulty being applied in commercial lithium ion batteries. In this study, we report a novel method using amorphous silicon

  8. Oxy-combustion of high water content fuels

    Science.gov (United States)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  9. Feasibility study on silicon doping using high temperature test engineering reactor

    International Nuclear Information System (INIS)

    Seki, Masaya; Takaki, Naoyuki; Goto, Minoru; Shimakawa, Satoshi

    2011-01-01

    The feasibility study on silicon doping using the High Temperature engineering Test Reactor (HTTR) is performed by numerical simulations. The HTTR is a High Temperature Gas-cooled Reactor (HTGR) situated at JAEA Oarai research and development center. It has a 30MW thermal power and the outlet coolant temperature is 950degC. The objective of this study is to evaluate the following issues, 1. The impact of loading Si-ingots into the core on the criticality, 2. The uniformity of the neutron capture reaction rate in Si-ingots, and 3. The production rate of silicon semiconductor. In this study, six Si-ingots are loaded into the irradiation area which is located in the peripheral region of the core. They are irradiated with rotation movement around the axial direction to obtain uniform neutron capture reaction rate in the radial direction. Additionally, the neutron filter, which is made of graphite containing boron, is used to obtain uniform neutron capture reaction rate in the axial direction. The evaluations were conducted by performing the HTTR whole core calculations with the Monte Carlo code MVP-2.0. In the calculations, several tally regions were defined on the Si-ingots to investigate the uniformity of the neutron capture reaction rate. As a result, loading the Si-ingots into the core causes negative reactivity by about 0.7%dk/k. Uniform neutron capture reaction rate of Si-ingot is obtained 98% in the radial and the axial direction. In case of the target of semiconductor resistivity is set to 50 Ωcm, the required irradiation time becomes 10 hours. The HTTR is able to produce silicon semiconductor of 540kg in one-time irradiation. This study was conducted as a joint research with JAEA, Nuclear Fuel Industries, LTD, Toyota Tsusho Corporation and Tokai University. (author)

  10. Silicon alleviates deleterious effects of high salinity on the halophytic grass Spartina densiflora.

    Science.gov (United States)

    Mateos-Naranjo, Enrique; Andrades-Moreno, Luis; Davy, Anthony J

    2013-02-01

    The non-essential element silicon is known to improve plant fitness by alleviating the effects of biotic and abiotic stresses, particularly in crops. However, its possible role in the exceptional tolerance of halophytes to salinity has not been investigated. This study reports the effect of Si supply on the salinity tolerance of the halophytic grass Spartina densiflora; plants were treated with NaCl (0-680 mM), with or without silicon addition of 500 μM, in a glasshouse experiment. Plant responses were examined using growth analysis, combined with measurements of gas exchange, chlorophyll fluorescence and photosynthetic pigment concentrations. In addition, tissue concentrations of aluminium, calcium, copper, iron, potassium, magnesium, sodium, phosphorus and silicon were determined. Although high salinity decreased growth, this effect was alleviated by treatment with Si. Improved growth was associated with higher net photosynthetic rate (A), and greater water-use efficiency (WUE). Enhanced A at high salinity could be explained by beneficial effects of Si on the photochemical apparatus, and on chlorophyll concentrations. Ameliorative effects of Si were correlated with reduced sodium uptake, which was unrelated to a reduction in the transpiration rate, since Si-supplemented plants had higher stomatal conductances (G(s)). These plants also had higher tissue concentrations of essential nutrients, suggesting that Si had a positive effect on the mineral nutrient balance in salt-stressed plants. Si appears to play a significant role in salinity tolerance even in a halophyte, which has other, specific salt-tolerance mechanisms, through diverse protective effects on the photosynthetic apparatus, water-use efficiency and mineral nutrient balance. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. DC characteristics and parameters of silicon carbide high-voltage power BJTs

    International Nuclear Information System (INIS)

    Patrzyk, Joanna; Zarębski, Janusz; Bisewski, Damian

    2016-01-01

    The paper shows the static characteristics and operating parameters of the bipolar power transistors made of silicon carbide and for comparison their equivalents made of classical silicon technology. The characteristics and values of selected operating parameters with special emphasis on the effect of temperature and operating point of considered devices are discussed. Quantitative as well as qualitative differences between the characteristics of the transistor made of silicon and silicon carbide are indicated as well

  12. Method development and validation for simultaneous determination of IEA-R1 reactor’s pool water uranium and silicon content by ICP OES

    Science.gov (United States)

    Ulrich, J. C.; Guilhen, S. N.; Cotrim, M. E. B.; Pires, M. A. F.

    2018-03-01

    IPEN’s research reactor, IEA-R1, an open pool type research reactor moderated and cooled by light water. High quality water is a key factor in preventing the corrosion of the spent fuel stored in the pool. Leaching of radionuclides from the corroded fuel cladding may be prevented by an efficient water treatment and purification system. However, as a safety management policy, IPEN has adopted a water chemistry control which periodically monitors the levels of uranium (U) and silicon (Si) in the pool’s reactor, since IEA-R1 employs U3Si2-Al dispersion fuel. An analytical method was developed and validated for the determination of uranium and silicon by ICP OES. This work describes the validation process, in a context of quality assurance, including the parameters selectivity, linearity, quantification limit, precision and recovery.

  13. Microstructure and mechanical properties of a new type of austempered boron alloyed high silicon cast steel

    Directory of Open Access Journals (Sweden)

    Chen Xiang

    2013-05-01

    Full Text Available In the present paper, a new type of austempered boron alloyed high silicon cast steel has been developed, and its microstructures and mechanical properties at different temperatures were investigated. The experimental results indicate that the boron alloyed high silicon cast steel comprises a dendritic matrix and interdendritic eutectic borides in as-cast condition. The dendritic matrix is made up of pearlite, ferrite, and the interdendritic eutectic boride is with a chemical formula of M2B (M represents Fe, Cr, Mn or Mo which is much like that of carbide in high chromium white cast iron. Pure ausferrite structure that consists of bainitic ferrite and retained austenite can be obtained in the matrix by austempering treatment to the cast steel. No carbides precipitate in the ausferrite structure and the morphology of borides remains almost unchanged after austempering treatments. Secondary boride particles precipitate during the course of austenitizing. The hardness and tensile strength of the austempered cast steel decrease with the increase of the austempering temperature, from 250 篊 to 400 篊. The impact toughness is 4-11 J昪m-2 at room temperature and the impact fracture fractogragh indicates that the fracture is caused by the brittle fracture of the borides.

  14. Large-Area Silicon Detectors for the CMS High Granularity Calorimeter

    CERN Document Server

    Pree, Elias

    2017-01-01

    During the so-called Phase-2 Upgrade, the CMS experiment at CERN will undergo significant improvements to cope with the 10-fold luminosity increase of the High Luminosity LHC (HL-LHC) era. Especially the forward calorimetry will suffer from very high radiation levels and intensified pileup in the detectors. For this reason, the CMS collaboration is designing a High Granularity Calorimeter (HGCAL) to replace the existing endcap calorimeters. It features unprecedented transverse and longitudinal segmentation for both electromagnetic (CE-E) and hadronic (CE-H) compartments. The CE-E and a large fraction of CE-H will consist of a sandwich structure with silicon as active detector material. This paper presents an overview of the ongoing sensor development for the HGCAL and highlights important design features and measurement techniques. The design and layout of an 8-inch silicon sensor prototype is shown. The hexagonal sensors consist of 235 pads, each with an area of about \\mbox{1~cm$^{2}$}. Furthermore, Synopsys...

  15. High-Efficiency Silicon/Organic Heterojunction Solar Cells with Improved Junction Quality and Interface Passivation.

    Science.gov (United States)

    He, Jian; Gao, Pingqi; Ling, Zhaoheng; Ding, Li; Yang, Zhenhai; Ye, Jichun; Cui, Yi

    2016-12-27

    Silicon/organic heterojunction solar cells (HSCs) based on conjugated polymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and n-type silicon (n-Si) have attracted wide attention due to their potential advantages of high efficiency and low cost. However, the state-of-the-art efficiencies are still far from satisfactory due to the inferior junction quality. Here, facile treatments were applied by pretreating the n-Si wafer in tetramethylammonium hydroxide (TMAH) solution and using a capping copper iodide (CuI) layer on the PEDOT:PSS layer to achieve a high-quality Schottky junction. Detailed photoelectric characteristics indicated that the surface recombination was greatly suppressed after TMAH pretreatment, which increased the thickness of the interfacial oxide layer. Furthermore, the CuI capping layer induced a strong inversion layer near the n-Si surface, resulting in an excellent field effect passivation. With the collaborative improvements in the interface chemical and electrical passivation, a competitive open-circuit voltage of 0.656 V and a high fill factor of 78.1% were achieved, leading to a stable efficiency of over 14.3% for the planar n-Si/PEDOT:PSS HSCs. Our findings suggest promising strategies to further exploit the full voltage as well as efficiency potentials for Si/organic solar cells.

  16. Silicon microstrip detector development in the Institute for High Energy Physics Zeuthen, GDR

    International Nuclear Information System (INIS)

    Lange, W.; Nowak, W.D.; Truetzschler, K.

    1990-01-01

    This paper reports that in regard of the growing interest to study short living particles demanding for high resolution vertex detectors the authors started to build Si microstrip detectors. The first detector generation was characterized by a small area of silicon and a readout via printed circuit board fan out. Now they can assemble detectors with larger areas and VLSI readout. A special cleanroom has been built. Equipment and tools necessary are available. Silicon wafers and thick film hybrid circuits are fabricated under collaboration by the GDR industry. Applications of their detectors were several test-runs at CERN to calibrate the L3 time expansion chamber (TEC) and the L3 muon chambers. A 10-layer telescope is designed now and it is planned to calibrate a high resolution scintillation fiber target. Future applications will be high resolution vertex detectors, e.g. L3 upgrading (LEP, CERN) or KEDR (VEPP-5, Novosibirsk). Further investigations will concern AC coupled strip detectors (single and double sided) and pixel and/or pad detectors

  17. Equivalences between refractive index and equilibrium water content of conventional and silicone hydrogel soft contact lenses from automated and manual refractometry.

    Science.gov (United States)

    González-Méijome, José M; López-Alemany, Antonio; Lira, Madalena; Almeida, José B; Oliveira, M Elisabete C D Real; Parafita, Manuel A

    2007-01-01

    The purpose of the present study was to develop mathematical relationships that allow obtaining equilibrium water content and refractive index of conventional and silicone hydrogel soft contact lenses from refractive index measures obtained with automated refractometry or equilibrium water content measures derived from manual refractometry, respectively. Twelve HEMA-based hydrogels of different hydration and four siloxane-based polymers were assayed. A manual refractometer and a digital refractometer were used. Polynomial models obtained from the sucrose curves of equilibrium water content against refractive index and vice-versa were used either considering the whole range of sucrose concentrations (16-100% equilibrium water content) or a range confined to the equilibrium water content of current soft contact lenses (approximately 20-80% equilibrium water content). Values of equilibrium water content measured with the Atago N-2E and those derived from the refractive index measurement with CLR 12-70 by the applications of sucrose-based models displayed a strong linear correlation (r2 = 0.978). The same correlations were obtained when the models are applied to obtain refractive index values from the Atago N-2E and compared with those (values) given by the CLR 12-70 (r2 = 0.978). No significantly different results are obtained between models derived from the whole range of the sucrose solution or the model limited to the normal range of soft contact lens hydration. Present results will have implications for future experimental and clinical research regarding normal hydration and dehydration experiments with hydrogel polymers, and particularly in the field of contact lenses. 2006 Wiley Periodicals, Inc.

  18. In situ nanoscale refinement by highly controllable etching of the (111) silicon crystal plane and its influence on the enhanced electrical property of a silicon nanowire

    International Nuclear Information System (INIS)

    Gong Yibin; Dai Pengfei; Gao Anran; Li Tie; Zhou Ping; Wang Yuelin

    2011-01-01

    Nanoscale refinement on a (100) oriented silicon-on-insulator (SOI) wafer was introduced by using tetra-methyl-ammonium hydroxide (TMAH, 25 wt%) anisotropic silicon etchant, with temperature kept at 50 °C to achieve precise etching of the (111) crystal plane. Specifically for a silicon nanowire (SiNW) with oxide sidewall protection, the in situ TMAH process enabled effective size reduction in both lateral (2.3 nm/min) and vertical (1.7 nm/min) dimensions. A sub-50 nm SiNW with a length of microns with uniform triangular cross-section was achieved accordingly, yielding enhanced field effect transistor (FET) characteristics in comparison with its 100 nm-wide pre-refining counterpart, which demonstrated the feasibility of this highly controllable refinement process. Detailed examination revealed that the high surface quality of the (111) plane, as well as the bulk depletion property should be the causes of this electrical enhancement, which implies the great potential of the as-made cost-effective SiNW FET device in many fields. (semiconductor materials)

  19. Serially Connected Micro Amorphous Silicon Solar Cells for Compact High-Voltage Sources

    Directory of Open Access Journals (Sweden)

    Jiyoon Nam

    2016-01-01

    Full Text Available We demonstrate a compact amorphous silicon (a-Si solar module to be used as high-voltage power supply. In comparison with the organic solar module, the main advantages of the a-Si solar module are its compatibility with photolithography techniques and relatively high power conversion efficiency. The open circuit voltage of a-Si solar cells can be easily controlled by serially interconnecting a-Si solar cells. Moreover, the a-Si solar module can be easily patterned by photolithography in any desired shapes with high areal densities. Using the photolithographic technique, we fabricate a compact a-Si solar module with noticeable photovoltaic characteristics as compared with the reported values for high-voltage power supplies.

  20. Rhodium Nanoparticle-mesoporous Silicon Nanowire Nanohybrids for Hydrogen Peroxide Detection with High Selectivity

    Science.gov (United States)

    Song, Zhiqian; Chang, Hucheng; Zhu, Weiqin; Xu, Chenlong; Feng, Xinjian

    2015-01-01

    Developing nanostructured electrocatalysts, with low overpotential, high selectivity and activity has fundamental and technical importance in many fields. We report here rhodium nanoparticle and mesoporous silicon nanowire (RhNP@mSiNW) hybrids for hydrogen peroxide (H2O2) detection with high electrocatalytic activity and selectivity. By employing electrodes that loaded with RhNP@mSiNW nanohybrids, interference caused from both many electroactive substances and dissolved oxygen were eliminated by electrochemical assaying at an optimal potential of +75 mV. Furthermore, the electrodes exhibited a high detection sensitivity of 0.53 μA/mM and fast response (< 5 s). This high-performance nanohybrid electrocatalyst has great potential for future practical application in various oxidase-base biosensors. PMID:25588953

  1. Determinations of silicon and phosphorus in rice planted on a district of high incidence of amyotrophic lateral sclerosis by neutron activation and X-ray fluorescence analyses

    Energy Technology Data Exchange (ETDEWEB)

    Mizumoto, Yoshihiko; Ishikawa, Teruumi; Kusakabe, Toshio; Katsurayama, Kousuke (Kinki Univ., Higashi-Osaka, Osaka (Japan)); Iwata, Shiro

    1989-12-01

    Silicon and phosphorus contents in polished and unpolished rice planted on a district of high incidence of amyotrophic lateral sclerosis (ALS) have been determined by neutron activation and X-ray fluorescence methods, and compared with those from control areas. In the neutron activation analysis, {beta}-ray spectra of {sup 32}P produced by the {sup 31}P(n, {gamma}){sup 32}P reaction on polished and unpolished rice were measured with a low background {beta}-ray spectrometer. In the X-ray fluorescence analysis, characteristic X-ray were analyzed with a wavelength dispersive X-ray fluorescence spectrometer. Silicon contents in polished and unpolished rice from the ALS area are 42 {mu}g.g{sup -1} and 370 {mu}g.g{sup -1}, respectively, and the corresponding phosphorus contents are 1210 {mu}g.g{sup -1}, and 3370 {mu}g.g{sup -1}, respectively. The data for ALS area are equal to those for the control area within atandard deviation. (author).

  2. Gravel Mobility in a High Sand Content Riverbed

    Science.gov (United States)

    Haschenburger, J. K.

    2017-12-01

    In sand-gravel channels, sand may modify gravel transport by changing conditions of entrainment and promoting longer displacements or gravel may inhibit sand transport if concentrated into distinct deposits, which restrict sand supply with consequences for migrating bedform size or form. This study reports on gravel mobility in the lower San Antonio River, Texas, where gravel content in the bed material ranges from about 1% to more than 20%. Sediment transport observations were collected at three U.S. Geological Survey gauging stations by deploying a Helley-Smith sampler with a 0.2 mm mesh bag from which transport rates and mobile grain sizes were determined. The flow rates sampled translate into an annual exceedance expectation from 0.2% to 98%. Gravel transport rates are generally two orders of magnitude smaller than the rates of sand transport. However, the finest gravels are transported at rates on the same order of magnitude as the coarsest sands. At all sites, the 2 and 2.8 mm fractions are transported at the lowest flow rate sampled, suggesting mobility for at least 38% to as much as 98% of the year. Fractions as large as 8 mm are mobilized at flow rates that are expected between 25% and 53% of the year. The largest fractions captured in the sampling (16 to 32 mm) require flows closer to bankfull conditions that occur no more than 0.8% of the year. Results document that some gravel sizes can be frequently transported in low gradient riverbeds with high sand content.

  3. Silicon Priming Created an Enhanced Tolerance in Alfalfa (Medicago sativa L.) Seedlings in Response to High Alkaline Stress.

    Science.gov (United States)

    Liu, Duo; Liu, Miao; Liu, Xiao-Long; Cheng, Xian-Guo; Liang, Zheng-Wei

    2018-01-01

    Alkaline stress as a result of higher pH usually triggers more severe physiological damage to plants than that of saline stress with a neutral pH. In the present study, we demonstrated that silicon (Si) priming of alfalfa ( Medicago sativa L.) seedlings increased their tolerance to high alkaline stress situations. Gongnong No. 1 seedlings were subjected to alkaline stress simulated by 25 mM Na 2 CO 3 (pH 11.2). Alkaline stress greatly decreased the biomass and caused severe lodging or wilting of alfalfa seedlings. In contrast, the application of Si to alfalfa seedlings 36 h prior to the alkaline treatment significantly alleviated the damage symptoms and greatly increased the biomass and chlorophyll content. Because of being concomitant with increasing photosynthesis and water use efficiency, decreasing membrane injury and malondialdehyde content, and increasing peroxidase and catalase ascorbate activities in alfalfa leaves, thereby alleviating the triggered oxidative damage by alkaline stress to the plant. Furthermore, Si priming significantly decreased the accumulation of protein and proline content in alfalfa, thus reducing photosynthetic feedback repression. Si priming significantly accumulated more Na in the roots, but led to a decrease of Na accumulation and an increase of K accumulation in the leaves under alkaline stress. Meanwhile, Si priming decreased the accumulation of metal ions such as Mg, Fe, Mn, and Zn in the roots of alfalfa seedlings under alkaline stress. Collectively, these results suggested that Si is involved in the metabolic or physiological changes and has a potent priming effect on the alkaline tolerance of alfalfa seedlings. The present study indicated that Si priming is a new approach to improve the alkaline tolerance in alfalfa and provides increasing information for further exploration of the alkaline stress response at the molecular level in alfalfa.

  4. Fully Biodegradable Biocomposites with High Chicken Feather Content

    Directory of Open Access Journals (Sweden)

    Ibon Aranberri

    2017-11-01

    Full Text Available The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF. In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA, polybutyrate adipate terephthalate (PBAT and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a torque rheometer having a CF content of 50 and 60 wt %. Due to the low tensile strength of CFs, the resulting materials were penalized in terms of mechanical properties. However, high-loading CF biocomposites resulted in lightweight and thermal-insulating materials when compared with neat bioplastics. Additionally, the adhesion between CFs and the PLA matrix was also investigated and a significant improvement of the wettability of the feathers was obtained with the alkali treatment of the CFs and the addition of a plasticizer like polyethylene glycol (PEG. Considering all the properties, these 100% fully biodegradable biocomposites could be adequate for panel components, flooring or building materials as an alternative to wood–plastic composites, contributing to the valorisation of chicken feather waste as a renewable material.

  5. Development of automatic image analysis methods for high-throughput and high-content screening

    NARCIS (Netherlands)

    Di, Zi

    2013-01-01

    This thesis focuses on the development of image analysis methods for ultra-high content analysis of high-throughput screens where cellular phenotype responses to various genetic or chemical perturbations that are under investigation. Our primary goal is to deliver efficient and robust image analysis

  6. Growth of (100)-highly textured BaBiO{sub 3} thin films on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Ferreyra, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Departamento de Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 1, Ciudad Universitaria, Buenos Aires (Argentina); Marchini, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Departamento de Química Inorgánica, Analítica y Química-Física, INQUIMAE-CONICET, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires (Argentina); Granell, P. [INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Golmar, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, UNSAM, Campus Miguelete, 1650 San Martín, Buenos Aires (Argentina); Albornoz, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); and others

    2016-08-01

    We report on the growth and characterization of non-epitaxial but (100)-highly textured BaBiO{sub 3} thin films on silicon substrates. We have found the deposition conditions that optimize the texture, and show that the textured growth is favoured by the formation of a BaO layer at the first growth stages. X-ray diffraction Φ-scans, together with the observation that the same textured growth is found on films grown on Pt and SiO{sub 2} buffered Si, demonstrate the absence of epitaxy. Finally, we have shown that our (100)-oriented BaBiO{sub 3} films can be used as suitable buffers for the growth of textured heterostructures on silicon, which could facilitate the integration of potential devices with standard electronics. - Highlights: • BaBiO{sub 3} thin films were grown on Si substrates and characterized. • Films prepared using optimized conditions are highly textured in the (100) direction. • The absence of in-plane texture was demonstrated by X-ray diffraction. • Our films are suitable buffers for the growth of (100)-textured oxide heterostructures.

  7. Development and application of nuclear radiation detector made from high resistivity silicon and compound semiconductor

    International Nuclear Information System (INIS)

    Ding Honglin; Zhang Xiufeng; Zhang Wanchang; Li Jiang

    1995-11-01

    The development of high resistivity silicon detectors and compound semiconductor detectors as well as their application in nuclear medicine are described. It emphasizes on several key techniques in fabricating detectors in order to meet their application in nuclear medicine. As for a high resistivity silicon detector, its counting rate to 125 I 28.5 keV X-ray has to be improved. So employing a conic mesa structure can increase the thickness of samples, and can raise the electric field of collecting charges under the same bias voltage. As for a GaAs detector, its performance of collecting charges has to be improved. So the thicknesses of GaAs samples are decreased and proper thermal treatment to make Ni-Ge-Au ohmic contacts are employed. Applying a suitable reverse bias voltage can obtain a fully depleted detector, and can obtain a lower forward turn-on voltage and a thinner weak electric field region. After resolving these key techniques, the performance of GaAs detectors has been distinctly improved. The count rate to 125 I X-ray has increased by three or five times under the same testing condition and background circumstance (2 refs., 8 figs., 3 tabs.)

  8. Time-Efficient High-Resolution Large-Area Nano-Patterning of Silicon Dioxide

    Directory of Open Access Journals (Sweden)

    Li Lin

    2017-01-01

    Full Text Available A nano-patterning approach on silicon dioxide (SiO2 material, which could be used for the selective growth of III-V nanowires in photovoltaic applications, is demonstrated. In this process, a silicon (Si stamp with nanopillar structures was first fabricated using electron-beam lithography (EBL followed by a dry etching process. Afterwards, the Si stamp was employed in nanoimprint lithography (NIL assisted with a dry etching process to produce nanoholes on the SiO2 layer. The demonstrated approach has advantages such as a high resolution in nanoscale by EBL and good reproducibility by NIL. In addition, high time efficiency can be realized by one-spot electron-beam exposure in the EBL process combined with NIL for mass production. Furthermore, the one-spot exposure enables the scalability of the nanostructures for different application requirements by tuning only the exposure dose. The size variation of the nanostructures resulting from exposure parameters in EBL, the pattern transfer during nanoimprint in NIL, and subsequent etching processes of SiO2 were also studied quantitatively. By this method, a hexagonal arranged hole array in SiO2 with a hole diameter ranging from 45 to 75 nm and a pitch of 600 nm was demonstrated on a four-inch wafer.

  9. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

    Science.gov (United States)

    Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

    2017-04-01

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

  10. High rate particle tracking and ultra-fast timing with a thin hybrid silicon pixel detector

    Science.gov (United States)

    Fiorini, M.; Aglieri Rinella, G.; Carassiti, V.; Ceccucci, A.; Cortina Gil, E.; Cotta Ramusino, A.; Dellacasa, G.; Garbolino, S.; Jarron, P.; Kaplon, J.; Kluge, A.; Marchetto, F.; Mapelli, A.; Martin, E.; Mazza, G.; Morel, M.; Noy, M.; Nuessle, G.; Perktold, L.; Petagna, P.; Petrucci, F.; Poltorak, K.; Riedler, P.; Rivetti, A.; Statera, M.; Velghe, B.

    2013-08-01

    The Gigatracker (GTK) is a hybrid silicon pixel detector designed for the NA62 experiment at CERN. The beam spectrometer, made of three GTK stations, has to sustain high and non-uniform particle rate (∼ 1 GHz in total) and measure momentum and angles of each beam track with a combined time resolution of 150 ps. In order to reduce multiple scattering and hadronic interactions of beam particles, the material budget of a single GTK station has been fixed to 0.5% X0. The expected fluence for 100 days of running is 2 ×1014 1 MeV neq /cm2, comparable to the one foreseen in the inner trackers of LHC detectors during 10 years of operation. To comply with these requirements, an efficient and very low-mass (< 0.15 %X0) cooling system is being constructed, using a novel microchannel cooling silicon plate. Two complementary read-out architectures have been produced as small-scale prototypes: one is based on a Time-over-Threshold circuit followed by a TDC shared by a group of pixels, while the other makes use of a constant-fraction discriminator followed by an on-pixel TDC. The read-out ASICs are produced in 130 nm IBM CMOS technology and will be thinned down to 100 μm or less. An overview of the Gigatracker detector system will be presented. Experimental results from laboratory and beam tests of prototype bump-bonded assemblies will be described as well. These results show a time resolution of about 170 ps for single hits from minimum ionizing particles, using 200 μm thick silicon sensors.

  11. Highly Conductive, Mechanically Robust, and Electrochemically Inactive TiC/C Nanofiber Scaffold for High-Performance Silicon Anode Batteries

    KAUST Repository

    Yao, Yan; Huo, Kaifu; Hu, Liangbing; Liu, Nian; Cha, Judy J.; McDowell, Matthew T.; Chu, Paul K.; Cui, Yi

    2011-01-01

    Silicon has a high specific capacity of 4200 mAh/g as lithium-ion battery anodes, but its rapid capacity fading due to >300% volume expansion and pulverization presents a significant challenge for practical applications. Here we report a core-shell TiC/C/Si inactive/active nanocomposite for Si anodes demonstrating high specific capacity and excellent electrochemical cycling. The amorphous silicon layer serves as the active material to store Li+, while the inactive TiC/C nanofibers act as a conductive and mechanically robust scaffold for electron transport during the Li-Si alloying process. The core-shell TiC/C/Si nanocomposite anode shows ∼3000 mAh g-1 discharge capacity and 92% capacity retention after 100 charge/discharge cycles. The excellent cycling stability and high rate performance could be attributed to the tapering of the nanofibers and the open structure that allows facile Li ion transport and the high conductivity and mechanical stability of the TiC/C scaffold. © 2011 American Chemical Society.

  12. Highly Conductive, Mechanically Robust, and Electrochemically Inactive TiC/C Nanofiber Scaffold for High-Performance Silicon Anode Batteries

    KAUST Repository

    Yao, Yan

    2011-10-25

    Silicon has a high specific capacity of 4200 mAh/g as lithium-ion battery anodes, but its rapid capacity fading due to >300% volume expansion and pulverization presents a significant challenge for practical applications. Here we report a core-shell TiC/C/Si inactive/active nanocomposite for Si anodes demonstrating high specific capacity and excellent electrochemical cycling. The amorphous silicon layer serves as the active material to store Li+, while the inactive TiC/C nanofibers act as a conductive and mechanically robust scaffold for electron transport during the Li-Si alloying process. The core-shell TiC/C/Si nanocomposite anode shows ∼3000 mAh g-1 discharge capacity and 92% capacity retention after 100 charge/discharge cycles. The excellent cycling stability and high rate performance could be attributed to the tapering of the nanofibers and the open structure that allows facile Li ion transport and the high conductivity and mechanical stability of the TiC/C scaffold. © 2011 American Chemical Society.

  13. Oxygen measurements in thin ribbon silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hyland, S L; Ast, D G; Baghdadi, A

    1987-03-01

    The oxygen content of thin silicon ribbons grown by the dendritic web technique was measured using a modification of the ASTM method based on Fourier transform infrared spectroscopy. Web silicon was found to have a high oxygen content, ranging from 13 to 19 ppma, calculated from the absorption peak associated with interstitial oxygen and using the new ASTM conversion coefficient. The oxygen concentration changed by about 10% along the growth direction of the ribbon. In some samples, a shoulder was detected on the absorption peak. A similar shoulder in Czochralski grown material has been variously interpreted in the literature as due to a complex of silicon, oxygen, and vacancies, or to a phase of SiO/sub 2/ developed along dislocations in the material. In the case of web silicon, it is not clear which is the correct interpretation.

  14. Fast-timing Capabilities of Silicon Sensors for the CMS High-Granularity Calorimeter at the High-Luminosity LHC

    Science.gov (United States)

    Akchurin, Nural; CMS Collaboration

    2017-11-01

    We report on the signal timing capabilities of thin silicon sensors when traversed by multiple simultaneous minimum ionizing particles (MIP). Three different planar sensors, 133, 211, and 285 μm thick in depletion thickness, have been exposed to high energy muons and electrons at CERN. We describe signal shape and timing resolution measurements as well as the response of these devices as a function of the multiplicity of MIPs. We compare these measurements to simulations where possible. We achieve better than 20 ps timing resolution for signals larger than a few tens of MIPs.

  15. Improving optical properties of silicon nitride films to be applied in the middle infrared optics by a combined high-power impulse/unbalanced magnetron sputtering deposition technique.

    Science.gov (United States)

    Liao, Bo-Huei; Hsiao, Chien-Nan

    2014-02-01

    Silicon nitride films are prepared by a combined high-power impulse/unbalanced magnetron sputtering (HIPIMS/UBMS) deposition technique. Different unbalance coefficients and pulse on/off ratios are applied to improve the optical properties of the silicon nitride films. The refractive indices of the Si3N4 films vary from 2.17 to 2.02 in the wavelength ranges of 400-700 nm, and all the extinction coefficients are smaller than 1×10(-4). The Fourier transform infrared spectroscopy and x-ray diffractometry measurements reveal the amorphous structure of the Si3N4 films with extremely low hydrogen content and very low absorption between the near IR and middle IR ranges. Compared to other deposition techniques, Si3N4 films deposited by the combined HIPIMS/UBMS deposition technique possess the highest refractive index, the lowest extinction coefficient, and excellent structural properties. Finally a four-layer coating is deposited on both sides of a silicon substrate. The average transmittance from 3200 to 4800 nm is 99.0%, and the highest transmittance is 99.97% around 4200 nm.

  16. Control of the Gas Flow in an Industrial Directional Solidification Furnace for Production of High Purity Multicrystalline Silicon Ingots

    Directory of Open Access Journals (Sweden)

    Lijun Liu

    2015-01-01

    Full Text Available A crucible cover was designed as gas guidance to control the gas flow in an industrial directional solidification furnace for producing high purity multicrystalline silicon. Three cover designs were compared to investigate their effect on impurity transport in the furnace and contamination of the silicon melt. Global simulations of coupled oxygen (O and carbon (C transport were carried out to predict the SiO and CO gases in the furnace as well as the O and C distributions in the silicon melt. Cases with and without chemical reaction on the cover surfaces were investigated. It was found that the cover design has little effect on the O concentration in the silicon melt; however, it significantly influences CO gas transport in the furnace chamber and C contamination in the melt. For covers made of metal or with a coating on their surfaces, an optimal cover design can produce a silicon melt free of C contamination. Even for a graphite cover without a coating, the carbon concentration in the silicon melt can be reduced by one order of magnitude. The simulation results demonstrate a method to control the contamination of C impurities in an industrial directional solidification furnace by crucible cover design.

  17. Radiation-hard Silicon Photonics for Future High Energy Physics Experiments

    CERN Document Server

    AUTHOR|(CDS)2089774; Troska, Jan

    Collisions of proton beams in the Large Hadron Collider at CERN produce very high radiation levels in the innermost parts of the particle detectors and enormous amounts of measurement data. Thousands of radiation-hard optical links based on directly-modulated laser diodes are thus installed in the particle detectors to transmit the measurement data to the processing electronics. The radiation levels in the innermost regions of future particle detectors will be much higher than they are now. Alternative solutions to laser-based radiation-hard optical links have to be found since the performance of laser diodes decreases beyond the operation margin of the system when irradiated to sufficiently high radiation levels. Silicon Photonics (SiPh) is currently being investigated as a promising alternative technology. First tests have indeed shown that SiPh Mach-Zehnder modulators (MZMs) are relatively insensitive to a high neutron fluence. However, they showed a strong degradation when exposed to ionizing radiation. ...

  18. Screen Printing of Highly Loaded Silver Inks on Plastic Substrates Using Silicon Stencils.

    Science.gov (United States)

    Hyun, Woo Jin; Lim, Sooman; Ahn, Bok Yeop; Lewis, Jennifer A; Frisbie, C Daniel; Francis, Lorraine F

    2015-06-17

    Screen printing is a potential technique for mass-production of printed electronics; however, improvement in printing resolution is needed for high integration and performance. In this study, screen printing of highly loaded silver ink (77 wt %) on polyimide films is studied using fine-scale silicon stencils with openings ranging from 5 to 50 μm wide. This approach enables printing of high-resolution silver lines with widths as small as 22 μm. The printed silver lines on polyimide exhibit good electrical properties with a resistivity of 5.5×10(-6) Ω cm and excellent bending tolerance for bending radii greater than 5 mm (tensile strains less than 0.75%).

  19. Review of status developments of high-efficiency crystalline silicon solar cells

    Science.gov (United States)

    Liu, Jingjing; Yao, Yao; Xiao, Shaoqing; Gu, Xiaofeng

    2018-03-01

    In order to further improve cell efficiency and reduce cost in achieving grid parity, a large number of PV manufacturing companies, universities and research institutes have been devoted to a variety of low-cost and high-efficiency crystalline Si solar cells. In this article, the cell structures, characteristics and efficiency progresses of several types of high-efficiency crystalline Si solar cells that have been in small scale production or are promising in mass production are presented, including passivated emitter rear cell, tunnel oxide passivated contact solar cell, interdigitated back contact cell, heterojunction with intrinsic thin-layer cell, and heterojunction solar cells with interdigitated back contacts. Both the industrialization status and future development trend of high-efficiency crystalline silicon solar cells are also pinpointed.

  20. RBS and ERDA determinations of depth distributions of high-dose carbon ions implanted in silicon for silicon-carbide synthesis study

    International Nuclear Information System (INIS)

    Intarasiri, S.; Kamwanna, T.; Hallen, A.; Yu, L.D.; Janson, M.S.; Thongleum, C.; Possnert, G.; Singkarat, S.

    2006-01-01

    For ion beam synthesis of silicon carbide (SiC), a knowledge of the depth distribution of implanted carbon ions in silicon is crucial for successful development. Based on its simplicity and availability, we selected Rutherford backscattering spectrometry (RBS) as an analysis technique for this purpose. A self-developed computer program dedicated to extract depth profiles of lighter impurities in heavier matrix is established. For control, calculated results are compared with an other ion beam analysis (IBA) technique superior for studying lighter impurity in heavier substrate i.e. elastic recoil detection analysis (ERDA). The RBS was performed with a 1.7-MV Tandetron accelerator using He 2+ as the probe ions. The ERDA was performed with a 5-MV Pelletron accelerator using I 8+ as the probe ions. This work shows that the RBS-extracted data had no significant deviations from those of ERDA and simulations by SRIM2003 and SIIMPL computer codes. We also found that annealing at temperatures as high as 1000 deg. C had quite limited effect on the redistribution of carbon in silicon

  1. Inorganic Glue Enabling High Performance of Silicon Particles as Lithium Ion Battery Anode

    KAUST Repository

    Cui, Li-Feng

    2011-01-01

    Silicon, as an alloy-type anode material, has recently attracted lots of attention because of its highest known Li+ storage capacity (4200 mAh/g). But lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Silicon nanostructures such as nanowires and nanotubes can overcome the pulverization problem, however these nano-engineered silicon anodes usually involve very expensive processes and have difficulty being applied in commercial lithium ion batteries. In this study, we report a novel method using amorphous silicon as inorganic glue replacing conventional polymer binder. This inorganic glue method can solve the loss of contact issue in conventional silicon particle anode and enables successful cycling of various sizes of silicon particles, both nano-particles and micron particles. With a limited capacity of 800 mAh/g, relatively large silicon micron-particles can be stably cycled over 200 cycles. The very cheap production of these silicon particle anodes makes our method promising and competitive in lithium ion battery industry. © 2011 The Electrochemical Society.

  2. Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States)

    2013-11-01

    The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO{sub 2} anatase, TiO{sub 2} rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I{sub corr} than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO{sub 2}, HA, and Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4}. • Polarization resistance of the coating was increased by Si substitution in HA.

  3. A silicon strip detector used as a high rate focal plane sensor for electrons in a magnetic spectrometer

    CERN Document Server

    Miyoshi, T; Fujii, Y; Hashimoto, O; Hungerford, E V; Sato, Y; Sarsour, M; Takahashi, T; Tang, L; Ukai, M; Yamaguchi, H

    2003-01-01

    A silicon strip detector was developed as a focal plane sensor for a 300 MeV electron spectrometer and operated in a high rate environment. The detector with 500 mu m pitch provided good position resolution for electrons crossing the focal plane of the magnetic spectrometer system which was mounted in Hall C of the Thomas Jefferson National Accelerator Facility. The design of the silicon strip detector and the performance under high counting rate (<=2.0x10 sup 8 s sup - sup 1 for approx 1000 SSD channels) and high dose are discussed.

  4. Design and Implementation of High Performance Content-Addressable Memories.

    Science.gov (United States)

    1985-12-01

    content addressability and two basic implementations of content addressing. The need and application of hardware CAM is presented to motivate the " topic...3r Pass 4th Ps4 Pass Figure 2.15 Maximum SearchUsing All-Parallel CAM - left-most position (the most significant bit) and the other IF bits are zeros

  5. Corrosion resistance properties of enamels with high B2O3-P2O5 content to molten aluminum

    International Nuclear Information System (INIS)

    Zhou, M.; Li, K.; Shu, D.; Sun, B.D.; Wang, J.

    2003-01-01

    Anticorrosive properties of borophosphate and boron-free enamels to molten aluminum were investigated using SEM and electron probe. Carbonates of alkali metal and alkaline earth metal were added in an appropriate weight ratio to achieve desired melting temperature of the enamels. SEM examination on the solidified interface between the enamels and aluminum alloy show that the enamels can spread slightly on aluminum alloy. For anticorrosive sample of borophosphate enamel, phosphorus was not detected by electron probe at the side of aluminum alloy near the interface, but silicon was detected in the silica-free enamels side. For the sample of boron-free enamels, however, phosphorus was found at the side of aluminum alloy near the interface. It was revealed that the enamels with high B 2 O 3 -P 2 O 5 content have high corrosion resistance to molten aluminum

  6. Extraction-spectrophotometric method for silicon determination in high-purity substances. 2. Silicon determination in cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Yudelevich, I G; Shaburova, V P; Shamrina, L V [AN SSSR, Novosibirsk (USSR). Inst. Neorganicheskoj Khimii

    1989-01-01

    Cadmium extraction by tributyl phosphate and trialkylbenzylammonium chloride (TABAC) depending on acid (HCl, HI), extracting agent concentration, volume of aqueous and organic phases, number of extraction steps is investigated. On the basis of the obtained results the spectrophotometric method for silicon determination in cadmium and CdCl/sub 2/ using malachite green with preliminary extraction of the base by the TABAC from HCl solutions. The method detection limit is 3.9x10/sup -4/ % Si with respect to initial cadmium sample of 100 mg and 7.8x10/sup -5/ % with respect to 0.5 g of CdCl/sub 2/. The relative standard deviation is S/sub r/-0.07-0.13.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    Film conformality is one of the major drivers for the interest in atomic layer deposition (ALD) processes. This work presents new silicon-based microscopic lateral high-aspect-ratio (LHAR) test structures for the analysis of the conformality of thin films deposited by ALD and by other chemical vapor deposition means. The microscopic LHAR structures consist of a lateral cavity inside silicon with a roof supported by pillars. The cavity length (e.g., 20–5000 μm) and cavity height (e.g., 200–1000 nm) can be varied, giving aspect ratios of, e.g., 20:1 to 25 000:1. Film conformality can be analyzed with the microscopic LHAR by several means, as demonstrated for the ALD Al 2 O 3 and TiO 2 processes from Me 3 Al/H 2 O and TiCl 4 /H 2 O. The microscopic LHAR test structures introduced in this work expose a new parameter space for thin film conformality investigations expected to prove useful in the development, tuning and modeling of ALD and other chemical vapor deposition processes

  8. Influence of fabrication parameter on the nanostructure and photoluminescence of highly doped p-porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shaoyuan [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Ma, Wenhui, E-mail: mwhsilicon@163.com [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Zhou, Yang, E-mail: zhouyangnano@163.com [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Chen, Xiuhua [Faculty of Physical Science and Technology, Yunnan University, Kunming 650091 (China); Ma, Mingyu [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Xiao, Yongyin [Faculty of Physical Science and Technology, Yunnan University, Kunming 650091 (China); Xu, Yaohui [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China)

    2014-02-15

    Porous silicon (PS) was prepared by anodizing highly doped p-type silicon in the solution of H{sub 2}O/ethanol/HF. The effects of key fabrication parameters (HF concentration, etching time and current density) on the nanostructure of PS were carefully investigated by AFM, SEM and TEM characterization. According to the experimental results, a more full-fledged model was developed to explain the crack behaviors on PS surface. The photoluminescence (PL) of resulting PS was studied by a fluorescence spectrophotometer and the results show that PL peak positions shift to shorter wavelength with the increasing current density, anodisation time and dilution of electrolyte. The PL spectra blue shift of the sample with higher porosity is confirmed by HRTEM results that the higher porosity results in smaller Si nanocrystals. A linear model (λ{sub PL/nm}=620.3–0.595P, R=0.905) was established to describe the correlation between PL peak positions and porosity of PS. -- Highlights: • The effect of fabrication parameter on the nanostructure of PS is investigated. • The influence of nanostructure on the photoluminescence behaviors is studied • A full-fledged model for expounding the crack behaviors of PS is presented. • The correlation between the porosity and PL peak blue shift is described by a linear model.

  9. High-speed and efficient silicon modulator based on forward-biased pin diodes

    Directory of Open Access Journals (Sweden)

    Suguru eAkiyama

    2014-11-01

    Full Text Available Silicon modulators, which use the free-carrier-plasma effect, were studied, both analytically and experimentally. It was demonstrated that the loss-efficiency product, a-VpL, was a suitable figure of merit for silicon modulators that enabled their intrinsic properties to be compared. Subsequently, the dependence of VpL on frequency was expressed by using the electrical parameters of a phase shifter when the modulator was operated by assuming a simple driving configuration. A diode-based modulator operated in forward biased mode was expected from analyses to provide more efficient operation than that in reversed mode at high frequencies due to its large capacitance. We obtained an a-VpL of 9.5 dB-V at 12.5 GHz in experiments by using the fabricated phase shifter with pin diodes operated in forward biased mode. This a-VpL was comparable to the best modulators operated in depletion mode. The modulator exhibited a clear eye opening at 56 Gb/s operated by 2 V peak-to-peak signals that was achieved by incorporating such a phase shifter into a ring resonator.

  10. High resolution deep level transient spectroscopy and process-induced defects in silicon

    International Nuclear Information System (INIS)

    Evans-Freeman, J.H.; Emiroglu, D.; Vernon-Parry, K.D.

    2004-01-01

    High resolution, or Laplace, deep level transient spectroscopy (LDLTS) enables the identification of very closely spaced energetic levels in a semiconductor bandgap. DLTS may resolve peaks with a separation of tens of electron volts, but LDLTS can resolve defect energy separations as low as a few MeV. In this paper, we present results from LDLTS applied to ion implantation-induced defects in silicon, with particular emphasis on characterisation of end-of-range interstitial type defects. Silicon was implanted with a variety of ions from mass 28 to 166. A combination of LDLTS and direct capture cross-section measurements was employed to show that electrically active small extended defects were present in the as-implanted samples. Larger dislocations were then generated in Si by oxygenation to act as a control sample. These stacking faults had typical lengths of microns, and their electrical activity was subsequently characterised by LDLTS. This was to establish the sensitivity of LDLTS to defects whose carrier capture is characterised by a non-exponential filling process and an evolving band structure as carrier capture proceeds. The LDLTS spectra show several components in capacitance transients originating from both the end-of-range defects, and the stacking faults, and also clearly show that the carrier emission rates reduce as these extended defects fill with carriers. The end-of-range defects and the stacking faults are shown to have the same electrical behaviour

  11. Research of high speed data readout and pre-processing system based on xTCA for silicon pixel detector

    International Nuclear Information System (INIS)

    Zhao Jingzhou; Lin Haichuan; Guo Fang; Liu Zhen'an; Xu Hao; Gong Wenxuan; Liu Zhao

    2012-01-01

    As the development of the detector, Silicon pixel detectors have been widely used in high energy physics experiments. It needs data processing system with high speed, high bandwidth and high availability to read data from silicon pixel detectors which generate more large data. The same question occurs on Belle II Pixel Detector which is a new style silicon pixel detector used in SuperKEKB accelerator with high luminance. The paper describes the research of High speed data readout and pre-processing system based on xTCA for silicon pixel detector. The system consists of High Performance Computer Node (HPCN) based on xTCA and ATCA frame. The HPCN consists of 4XFPs based on AMC, 1 AMC Carrier ATCA Board (ACAB) and 1 Rear Transmission Module. It characterized by 5 high performance FPGAs, 16 fiber links based on RocketIO, 5 Gbit Ethernet ports and DDR2 with capacity up to 18GB. In a ATCA frame, 14 HPCNs make up a system using the high speed backplane to achieve the function of data pre-processing and trigger. This system will be used on the trigger and data acquisition system of Belle II Pixel detector. (authors)

  12. GENERALIZATION, FORMULATION AND HEAT CONTENTS OF SIMULATED MSW WITH HIGH MOISTURE CONTENT

    Directory of Open Access Journals (Sweden)

    A. JOHARI

    2012-12-01

    Full Text Available This paper presents a generalization technique for the formulation of simulated municipal solid waste. This technique is used for the elimination of the inconsistency in the municipal solid waste (MSW characteristics due to its heterogeneous nature. The compositions of simulated municipal solid waste were formulated from four major municipal waste streams components in Malaysia namely paper, plastic, food and yard waste. The technique produced four simplified waste generalization categories with composition of paper (19%, plastic (25%, food (27% and green waste (29% respectively. Comparative study was conducted for proximate analysis for the determination of volatile matter, fixed carbon and ash content. Ultimate analysis was performed for carbon and hydrogen content. The heat content for simulated and actual municipal solid waste showed good agreement. The moisture content of the simulated municipal solid waste and actual municipal solid waste were established at 52.34% and 61.71% respectively. Overall results were considered to be representative of the actual compositions of municipal solid waste in Malaysia.

  13. Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors

    International Nuclear Information System (INIS)

    Yan, Hai; Zou, Yi; Yang, Chun-Ju; Chakravarty, Swapnajit; Wang, Zheng; Tang, Naimei; Chen, Ray T.; Fan, Donglei

    2015-01-01

    A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensing purpose. With proper engineering of the passband, multiple high sensitivity PC microcavity sensors can be integrated into microarrays and be interrogated simultaneously between a single input and a single output port. The concept was demonstrated with a 2-channel L55 PC biosensor array containing PC waveguide filters. The experiment showed that the sensors on both channels can be monitored simultaneously from a single output spectrum. Less than 3 dB extra loss for the additional PC waveguide filter is observed

  14. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Y., E-mail: cycjty@sophie.q.t.u-tokyo.ac.jp [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Shimazoe, K.; Yan, X. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ueda, O.; Ishikura, T. [Fuji Electric Co., Ltd., Fuji, Hino, Tokyo 191-8502 (Japan); Fujiwara, T. [National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Uesaka, M.; Ohno, M. [Nuclear Professional School, the University of Tokyo, 2-22 Shirakata-shirane, Tokai, Ibaraki 319-1188 (Japan); Tomita, H. [Department of Quantum Engineering, Nagoya University, Furo, Chikusa, Nagoya 464-8603 (Japan); Yoshihara, Y. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Takahashi, H. [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2016-09-11

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  15. Phosphorus-doped silicon nanorod anodes for high power lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Chao Yan

    2017-01-01

    Full Text Available Heavy-phosphorus-doped silicon anodes were fabricated on CuO nanorods for application in high power lithium-ion batteries. Since the conductivity of lithiated CuO is significantly better than that of CuO, after the first discharge, the voltage cut-off window was then set to the range covering only the discharge–charge range of Si. Thus, the CuO core was in situ lithiated and acts merely as the electronic conductor in the following cycles. The Si anode presented herein exhibited a capacity of 990 mAh/g at the rate of 9 A/g after 100 cycles. The anode also presented a stable rate performance even at a current density as high as 20 A/g.

  16. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    International Nuclear Information System (INIS)

    Tian, Y.; Shimazoe, K.; Yan, X.; Ueda, O.; Ishikura, T.; Fujiwara, T.; Uesaka, M.; Ohno, M.; Tomita, H.; Yoshihara, Y.; Takahashi, H.

    2016-01-01

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  17. Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Hai, E-mail: hai.yan@utexas.edu; Zou, Yi; Yang, Chun-Ju [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, 10100 Burnet Rd., Austin, Texas 78758 (United States); Chakravarty, Swapnajit, E-mail: swapnajit.chakravarty@omegaoptics.com [Omega Optics, Inc., 8500 Shoal Creek Blvd., Austin, Texas 78757 (United States); Wang, Zheng [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, 10100 Burnet Rd., Austin, Texas 78758 (United States); Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712 (United States); Tang, Naimei; Chen, Ray T., E-mail: raychen@uts.cc.utexas.edu [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, 10100 Burnet Rd., Austin, Texas 78758 (United States); Omega Optics, Inc., 8500 Shoal Creek Blvd., Austin, Texas 78757 (United States); Fan, Donglei [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712 (United States); Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-03-23

    A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensing purpose. With proper engineering of the passband, multiple high sensitivity PC microcavity sensors can be integrated into microarrays and be interrogated simultaneously between a single input and a single output port. The concept was demonstrated with a 2-channel L55 PC biosensor array containing PC waveguide filters. The experiment showed that the sensors on both channels can be monitored simultaneously from a single output spectrum. Less than 3 dB extra loss for the additional PC waveguide filter is observed.

  18. R&D for a highly granular silicon tungsten electromagnetic calorimeter

    CERN Document Server

    Pöschl, R

    2015-01-01

    This article reports on first experience with the technological prototype of a highly- granular silicon-tungsten electromagnetic calorimeter as envisaged for the detectors at a future lepton collider. In the focus of the analysis is the performance of a highly integrated Application Specific Integrated Circuit designed to meet the requirements in terms of dynamic range, compactness and power consumption. The beam test results show that the circuit will allow a future detector with a signal over noise ratio of at least 10:1. To minimise the power dissipation the ASIC will be operated in a power pulsed mode. So far no conceptual problem was revealed but the studies show the way for further work. The prototype is read out by a DAQ system conceived to meet the needs of a trigger less system with a huge number of readout cells.

  19. High-speed carrier-depletion silicon Mach-Zehnder optical modulators with lateral PN junctions

    Directory of Open Access Journals (Sweden)

    Graham Trevor Reed

    2014-12-01

    Full Text Available This paper presents new experimental data from a lateral PN junction silicon Mach-Zehnder optical modulator. Efficiencies in the 1.4V.cm to 1.9V.cm range are demonstrated for drive voltages between 0V and 6V. High speed operation up to 52Gbit/s is also presented. The performance of the device which has its PN junction positioned in the centre of the waveguide is then compared to previously reported data from a lateral PN junction device with the junction self-aligned to the edge of the waveguide rib. An improvement in modulation efficiency is demonstrated when the junction is positioned in the centre of the waveguide. Finally we propose schemes for achieving high modulation efficiency whilst retaining self-aligned formation of the PN junction.

  20. On the nature of high field charge transport in reinforced silicone dielectrics: Experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanhui, E-mail: huangy12@rpi.edu; Schadler, Linda S. [Department of Material Science and Engineering, Rensselaer Polytechnic Institute, 110 8th street, Troy, New York 12180 (United States)

    2016-08-07

    The high field charge injection and transport properties in reinforced silicone dielectrics were investigated by measuring the time-dependent space charge distribution and the current under dc conditions up to the breakdown field and were compared with the properties of other dielectric polymers. It is argued that the energy and spatial distribution of localized electronic states are crucial in determining these properties for polymer dielectrics. Tunneling to localized states likely dominates the charge injection process. A transient transport regime arises due to the relaxation of charge carriers into deep traps at the energy band tails and is successfully verified by a Monte Carlo simulation using the multiple-hopping model. The charge carrier mobility is found to be highly heterogeneous due to the non-uniform trapping. The slow moving electron packet exhibits a negative field dependent drift velocity possibly due to the spatial disorder of traps.

  1. Liquid gallium cooling of silicon crystals in high intensity photon beams

    International Nuclear Information System (INIS)

    Smither, R.K.; Forster, G.A.; Bilderback, D.H.; Bedzyk, M.; Finkelstein, K.; Henderson, C.; White, J.; Berman, L.E.; Stefan, P.; Oversluizen, T.

    1989-01-01

    The high-brilliance, insertion-device-based photon beams of the next generation of synchrotron sources (Argonne's APS and Grenoble's ESRF) will deliver large thermal loads (1--10 kW) to the first optical elements. Considering the problems that present synchrotron users are experiencing with beams from recently installed insertion devices, new and improved methods of cooling these first optical elements, particularly when they are diffraction crystals, are clearly needed. A series of finite element calculations were performed to test the efficiency of new cooling geometries and various cooling fluids. The best results were obtained with liquid Ga metal flowing in channels just below the surface of the crystal. Ga was selected because of its good thermal conductivity and thermal capacity, low melting point, high boiling point, low kinetic viscosity, and very low vapor pressure. Its very low vapor pressure, even at elevated temperatures, makes it especially attractive in UHV conditions. A series of experiments were conducted at CHESS in February of 1988 that compared liquid gallium-cooled silicon diffraction crystals with water-cooled crystals. A six-pole wiggler beam was used to perform these tests on three different Si crystals, two with new cooling geometries and the one presently in use. A special high-pressure electromagnetic induction pump, recently developed at Argonne, was used to circulate the liquid gallium through the silicon crystals. In all experiments, the specially cooled crystal was used as the first crystal in a two crystal monochromator. An infrared camera was used to monitor the thermal profiles and correlated them with rocking curve measurements. A second set of cooling experiments were conducted in June of 1988 that used the intense, highly collimated beam from the newly installed ANL/CHESS undulator

  2. The STiC ASIC. High precision timing with silicon photomultipliers

    International Nuclear Information System (INIS)

    Harion, Tobias

    2015-01-01

    In recent years, Silicon Photomultipliers are being increasingly used for Time of Flight measurements in particle detectors. To utilize the high intrinsic time resolution of these sensors in detector systems, the development of specialized, highly integrated readout electronics is required. In this thesis, a mixed-signal application specific integrated circuit, named STiC, has been developed, characterized and integrated in a detector system. STiC has been specifically designed for high precision timing measurements with SiPMs, and is in particular dedicated to the EndoTOFPET-US project, which aims to achieve a coincidence time resolution of 200 ps FWHM and an energy resolution of less than 20% in an endoscopic positron emission tomography system. The chip integrates 64 high precision readout channels for SiPMs together with a digital core logic to process, store and transfer the recorded events to a data acquisition system. The performance of the chip has been validated in coincidence measurements using detector modules consisting of 3.1 x 3.1 x 15 mm 3 LYSO crystals coupled to Silicon Photomultipliers from Hamamatsu. The measurements show an energy resolution of 15% FWHM for the detection of 511 keV photons. A coincidence time resolution of 213 ps FWHM has been measured, which is among the best resolution values achieved to date with this detector topology. STiC has been integrated in the EndoTOFPET-US detector system and has been chosen as the baseline design for the readout of SiPM sensors in the Mu3e experiment.

  3. Spectrophotometric determination of silicon in silumin matrix

    International Nuclear Information System (INIS)

    Samanta, Papu; Pandey, K.L.; Kumar, Pradeep; Bagchi, A.C.; Abdulla, K.K.

    2015-01-01

    In dispersion fuel, fissile material is dispersed in inert matrix. Aluminum-silicon-nickel (silumin) alloy is employed as inert matrix owing to its high thermal conductivity, high castability, high corrosion resistance. All these properties depend on the chemical composition and the structure of silumin. Silicon is stringent specification in silumin. A spectrophotometric method has been developed for the determination of silicon content in silumin matrix. Silumin matrix was fused with LiOH and subsequent dissolution in water along with few drops of conc. sulphuric acid. The molybodo-silicic formed by the addition of ammonium molybdate is reduced to molybdenum blue by ascorbic acid in the presence of antimony. The absorbance was measured at 810 nm. Aluminum and nickel were found to be non-interfering with the silicon determination. (author)

  4. Encapsulating of high-level radioactive waste with use of pyrocarbon and silicon carbide coatings

    International Nuclear Information System (INIS)

    Chernikov, A.

    2007-01-01

    It is known that high-level radioactive waste (HLW) constitute a real danger to biosphere, especially that their part, which contains transuranium and long-lived radionuclides resulting during reprocessing of nuclear fuel industrial and power reactors. Such waste contains approximately 99 % of long-lived fission products and transplutonium elements. At present, the concept of multi barrier protection of biosphere from radioactive waste is generally acknowledged. The main barriers are the physicochemical form of waste and enclosing strata of geological formation at places of waste-disposal. Applied methods of solidification of HLW with preparation of phosphatic and borosilicate glasses do not guarantee in full measure safety of places of waste-disposal of solidified waste in geological formations during thousand years. One promising way to improve HLW handling safety is placing of radionuclides in mineral-like matrixes similar to natural materials. The other possible way to increase safety of HLW disposal places is suggested for research by experts of Russian research institutes, for example, in the proposal for the Project of ISTC and considered in the present report, is to introduce an additional barrier on a radionuclides migration path by coating of HLW particles. Unique protective properties of pyrocarbon and silicon carbide such as low coefficients of diffusion of gaseous and solid fission products and high chemical and radiation stability [1] attract attention to these materials for coating of solidified HLW. The objective of the Project is the development of method of HLW encapsulating with use of pyrocarbon and silicon carbide coatings. To gain this end main direction of researches, including analysis of various encapsulation processes of fractionated HLW, and expected results are presented. Realization of the Project will allow to prove experimentally the efficiency of the proposed approach in the solution of the problem of HLW conditioning and ecological

  5. Structural and Electrochemical Investigation during the First Charging Cycles of Silicon Microwire Array Anodes for High Capacity Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Helmut Föll

    2013-02-01

    Full Text Available Silicon microwire arrays embedded in Cu present exceptional performance as anode material in Li ion batteries. The processes occurring during the first charging cycles of batteries with this anode are essential for good performance. This paper sheds light on the electrochemical and structural properties of the anodes during the first charging cycles. Scanning Electron Microscopy, X-ray diffractommetry, and fast Fourier transformation impedance spectroscopy are used for the characterization. It was found that crystalline phases with high Li content are obtained after the first lithiation cycle, while for the second lithiation just crystalline phases with less Li are observable, indicating that the lithiated wires become amorphous upon cycling. The formation of a solid electrolyte interface of around 250 nm during the first lithiation cycle is evidenced, and is considered a necessary component for the good cycling performance of the wires. Analog to voltammetric techniques, impedance spectroscopy is confirmed as a powerful tool to identify the formation of the different Si-Li phases.

  6. Dispersion of silicon carbide nanoparticles in a AA2024 aluminum alloy by a high-energy ball mill

    International Nuclear Information System (INIS)

    Carreño-Gallardo, C.; Estrada-Guel, I.; López-Meléndez, C.; Martínez-Sánchez, R.

    2014-01-01

    Highlights: • Synthesis of 2024-SiC NP nanocomposite by mechanical milling process. • SiC nanoparticles improved mechanical properties of aluminum alloy 2024 matrix. • A homogeneous distribution of SiC nanoparticles were observed in the matrix • Compressive and hardness properties of the composite are improved significantly. -- Abstract: Al 2024 alloy was reinforced with silicon carbide nanoparticles (SiC NP ), whose concentration was varied in the range from 0 to 5 wt.%; some composites were synthesized with the mechanical milling (MM) process. Structure and microstructure of the consolidated samples were studied by X-ray diffraction and transmission electron microscopy, while mechanical properties were investigated by compressive tests and hardness measurements. The microstructural evidence shows that SiC NP were homogeneously dispersed into the Al 2024 alloy using high-energy MM after 2 h of processing. On the other hand, an increase of the mechanical properties (yield stress, maximum strength and hardness) was observed in the synthesized composites as a direct function of the SiC NP content. In this research several strengthening mechanisms were observed, but the main was the obstruction of dislocations movement by the addition of SiC NP

  7. The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

    Science.gov (United States)

    Yoo, Hana; Park, Soojin

    2010-06-01

    We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm × 5 cm.

  8. The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hana; Park, Soojin, E-mail: spark@unist.ac.kr [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology, Banyeon-ri 100, Ulsan 689-798 (Korea, Republic of)

    2010-06-18

    We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm x 5 cm.

  9. Dwarf mutant of Papaver somniferum with high morphine content

    International Nuclear Information System (INIS)

    Chauhan, S.P.; Patra, N.K.; Srivastava, H.K.

    1987-01-01

    Opium poppy, Papaver somniferum L. is an important medicinal plant known for its morphine, codeine, and thebaine alkaloids. This Institute had earlier released two latex opium yielding poppy varieties, Shyama and Shweta, which are now cultivated by the farmers under the supervision of the Narcotic Department of the Government of India. However, both these varieties became susceptible to downy mildew (Peronospora arborescens). Lodging due to heavy capsule weight is another problem affecting latex yield. With these problems in mind, we undertook mutation breeding on the above mentioned two varieties employing gamma rays (5 kR, 15 kR, 20 kR) and EMS (0.2%, 0.4%, 0.6%) and combined mutagens (5 kR + 0.2% EMS, 5 kR + 0.4% EMS and 5 kR + 0.6% EMS). M 1 from the treated seeds (405 plants) was raised in winter 1984-85. M 2 generation of 13,500 plants (i.e. 270 M 1 progenies x 50 plants) was raised in winter 1985/86. A dwarf mutant with high morphine content was identified in M 2 from the variety Shweta treated with 5 kR + 0.4% EMS. The mutant differs by its dwarf stature, compact leaf arrangements, multilocular capsules, increased capsule number, and small capsule size. The mutant is under testing for its superior morphine production. It may be used as dwarf gene source in hybridization for improving lodging resistance. This mutant is a novel type, which was not available in our germplasm collection

  10. Interpenetrated polymer networks based on commercial silicone elastomers and ionic networks with high dielectric permittivity and self-healing properties

    DEFF Research Database (Denmark)

    Ogliani, Elisa; Yu, Liyun; Skov, Anne Ladegaard

    the applicability. One method used to avoid this limitation is to increase the dielectric permittivity of the material in order to improve the actuation response at a given field. Recently, interpenetrating polymer networks (IPNs) based on covalently cross-linked commercial silicone elastomers and ionic networks...... from amino- and carboxylic acid- functional silicones have been designed[2] (Figure 1). This novel system provides both the mechanical stability and the high breakdown strength given by the silicone part of the IPNs and the high permittivity and the softening effect of the ionic network. Thus......,1 Hz), and the commercial elastomers RT625 and LR3043/30 provide thebest viscoelastic properties to the systems, since they maintain low viscous losses upon addition of ionic network. The values ofthe breakdown strength in all cases remain higher than that of the reference pure PDMS network (ranging...

  11. Characteristics of MOSFETs fabricated in silicon-on-insulator material formed by high-dose oxygen ion implantation

    International Nuclear Information System (INIS)

    Lam, H.W.; Pinizzotto, R.F.; Yuan, H.T.; Bellavance, D.W.

    1981-01-01

    By implanting a dose of 6 x 10 17 cm -2 of 32 O 2 + at 300 keV into a silicon wafer, a buried oxide layer is formed. Crystallinity of the silicon layer above the buried oxide layer is maintained by applying a high (>200 0 C) substrate temperature during the ion implantation process. A two-step anneal cycle is found to be adequate to form the insulating buried oxide layer and to repair the implantation damage in the silicon layer on top of the buried oxide. A surface electron mobility as high as 710 cm 2 /Vs has been measured in n-channel MOSFETs fabricated in a 0.5 μm-thick epitaxial layer grown on the buried oxide wafer. A minimum subthreshold current of about 10 pA per micron of channel width at Vsub(DS)=2 V has been measured. (author)

  12. Optimization of HNA etching parameters to produce high aspect ratio solid silicon microneedles

    International Nuclear Information System (INIS)

    Hamzah, A A; Yeop Majlis, B; Yunas, J; Dee, C F; Abd Aziz, N; Bais, B

    2012-01-01

    High aspect ratio solid silicon microneedles with a concave conic shape were fabricated. Hydrofluoric acid–nitric acid–acetic acid (HNA) etching parameters were characterized and optimized to produce microneedles that have long and narrow bodies with smooth surfaces, suitable for transdermal drug delivery applications. The etching parameters were characterized by varying the HNA composition, the optical mask's window size, the etching temperature and bath agitation. An L9 orthogonal Taguchi experiment with three factors, each having three levels, was utilized to determine the optimal fabrication parameters. Isoetch contours for HNA composition with 0% and 10% acetic acid concentrations were presented and a high nitric acid region was identified to produce microneedles with smooth surfaces. It is observed that an increase in window size indiscriminately increases the etch rate in both the vertical and lateral directions, while an increase in etching temperature beyond 35 °C causes the etching to become rapid and uncontrollable. Bath agitation and sample placement could be manipulated to achieve a higher vertical etch rate compared to its lateral counterpart in order to construct high aspect ratio microneedles. The Taguchi experiment performed suggests that a HNA composition of 2:7:1 (HF:HNO 3 :CH 3 COOH), window size of 500 µm and agitation rate of 450 RPM are optimal. Solid silicon microneedles with an average height of 159.4 µm, an average base width of 110.9 µm, an aspect ratio of 1.44, and a tip angle and diameter of 19.2° and 0.38 µm respectively were successfully fabricated. (paper)

  13. High-performance silicon nanotube tunneling FET for ultralow-power logic applications

    KAUST Repository

    Fahad, Hossain M.; Hussain, Muhammad Mustafa

    2013-01-01

    To increase typically low output drive currents from tunnel field-effect transistors (FETs), we show a silicon vertical nanotube (NT) architecture-based FET's effectiveness. Using core (inner) and shell (outer) gate stacks, the silicon NT tunneling FET shows a sub-60 mV/dec subthreshold slope, ultralow off -state leakage current, higher drive current compared with gate-all-around nanowire silicon tunnel FETs. © 1963-2012 IEEE.

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

    OpenAIRE

    Tan, H.

    2015-01-01

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

  15. High-performance silicon nanotube tunneling FET for ultralow-power logic applications

    KAUST Repository

    Fahad, Hossain M.

    2013-03-01

    To increase typically low output drive currents from tunnel field-effect transistors (FETs), we show a silicon vertical nanotube (NT) architecture-based FET\\'s effectiveness. Using core (inner) and shell (outer) gate stacks, the silicon NT tunneling FET shows a sub-60 mV/dec subthreshold slope, ultralow off -state leakage current, higher drive current compared with gate-all-around nanowire silicon tunnel FETs. © 1963-2012 IEEE.

  16. Highly enhanced avalanche probability using sinusoidally-gated silicon avalanche photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Shingo; Namekata, Naoto, E-mail: nnao@phys.cst.nihon-u.ac.jp; Inoue, Shuichiro [Institute of Quantum Science, Nihon University, 1-8-14 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Tsujino, Kenji [Tokyo Women' s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan)

    2014-01-27

    We report on visible light single photon detection using a sinusoidally-gated silicon avalanche photodiode. Detection efficiency of 70.6% was achieved at a wavelength of 520 nm when an electrically cooled silicon avalanche photodiode with a quantum efficiency of 72.4% was used, which implies that a photo-excited single charge carrier in a silicon avalanche photodiode can trigger a detectable avalanche (charge) signal with a probability of 97.6%.

  17. Novel encapsulation technique for incorporation of high permittivity fillers into silicone elastomers

    DEFF Research Database (Denmark)

    Mazurek, Piotr Stanislaw; Hvilsted, Søren; Skov, Anne Ladegaard

    2014-01-01

    permittivity fillers, 2) Grafting of high permittivity molecules onto the polymer backbone in the elastomer, and 3) Encapsulation of high permittivity fillers. The approach investigated here is a new type of encapsulation which does not interfere with the mechanical properties to the same content...

  18. Enhanced mass removal due to phase explosion during high irradiance nanosecond laser ablation of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jong Hyun [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    The morphology of craters resulting from high irradiance laser ablation of silicon was measured using a white light interferometry microscope. The craters show a dramatic increase in their depth and volume at a certain irradiance, indicating a change in the primary mechanism for mass removal. Laser shadowgraph imaging was used to characterize and differentiate the mass ejection processes for laser irradiances above and below the threshold value. Time-resolved images show distinct features of the mass ejected at irradiances above the threshold value including the presence of micron-sized particulates; this begins at approximately 300 ~ 400 ns after the start of laser heating. The analysis of the phenomena was carried out by using two models: a thermal evaporation model and a phase explosion model. Estimation of the crater depth due to the thermally evaporated mass led to a large underestimation of the crater depth for irradiances above the threshold. Above the threshold irradiance, the possibility of phase explosion was analyzed. Two important results are the thickness of the superheated liquid layer that is close to the critical temperature and the time for vapor bubbles that are generated in the superheated liquid to achieve a critical size. After reaching the critical size, vapor bubbles can grow spontaneously resulting in a violent ejection of liquid droplets from the superheated volume. The effects of an induced transparency, i.e. of liquid silicon turning into an optically transparent liquid dielectric medium, are also introduced. The estimated time for a bubble to reach the critical size is in agreement with the delay time measured for the initiation of large mass ejection. Also, the thickness of the superheated liquid layer that is close to the critical temperature at the time of the beginning of the large mass ejection is representative of the crater depth at the threshold irradiance. These results suggest that phase explosion is a plausible thermal

  19. A high rate, low noise, x-ray silicon strip detector system

    International Nuclear Information System (INIS)

    Ludewigt, B.; Jaklevic, J.; Kipnis, I.; Rossington, C.; Spieler, H.

    1993-11-01

    An x-ray detector system, based on a silicon strip detector wire-bonded to a low noise charge-senstive amplifier integrated circuit, has been developed for synchrotron radiation experiments which require very high count rates and good energy resolution. Noise measurements and x-ray spectra were taken using a 6 mm long, 55 μm pitch strip detector in conjunction with a prototype 16-channel charge-sensitive preamplifier, both fabricated using standard 1.2 μm CMOS technology. The detector system currently achieves an energy resolution of 350 eV FWHM at 5.9 key, 2 μs peaking time, when cooled to -5 degree C

  20. High-fidelity adiabatic inversion of a {sup 31}P electron spin qubit in natural silicon

    Energy Technology Data Exchange (ETDEWEB)

    Laucht, Arne, E-mail: a.laucht@unsw.edu.au; Kalra, Rachpon; Muhonen, Juha T.; Dehollain, Juan P.; Mohiyaddin, Fahd A.; Hudson, Fay; Dzurak, Andrew S.; Morello, Andrea [Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052 (Australia); McCallum, Jeffrey C.; Jamieson, David N. [Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia)

    2014-03-03

    The main limitation to the high-fidelity quantum control of spins in semiconductors is the presence of strongly fluctuating fields arising from the nuclear spin bath of the host material. We demonstrate here a substantial improvement in single-qubit inversion fidelities for an electron spin qubit bound to a {sup 31}P atom in natural silicon, by applying adiabatic sweeps instead of narrow-band pulses. We achieve an inversion fidelity of 97%, and we observe signatures in the spin resonance spectra and the spin coherence time that are consistent with the presence of an additional exchange-coupled donor. This work highlights the effectiveness of simple adiabatic inversion techniques for spin control in fluctuating environments.

  1. UV and air stability of high-efficiency photoluminescent silicon nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jihua, E-mail: yangj@umn.edu [Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Liptak, Richard [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, 5500 Wabash Ave, Terre Haute, IN 47803 (United States); Rowe, David; Wu, Jeslin [Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Casey, James; Witker, David [Dow Corning Corporation, 2200 W. Salzburg Road, Midland, MI 48686 (United States); Campbell, Stephen A. [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Kortshagen, Uwe, E-mail: kortshagen@umn.edu [Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States)

    2014-12-30

    The effects of UV light and air exposure on the photoluminescent properties of nonthermal plasma-synthesized silicon nanocrystals (Si NCs) were investigated. Si NCs with high-efficiency photoluminescence (PL) have been achieved via a post-synthesis hydrosilylation process. Photobleaching is observed within the first few hours of ultra-violet (UV) irradiation. Equilibrium is reached after ∼4 h of UV exposure wherein the Si NCs are able to retain 52% of the initially measured PL quantum yield (PLQY). UV-treated Si NCs showed recovery of PL with time. Gas-phase passivation of Si NCs by hydrogen afterglow injection improves PLQY and PL stability against UV and air exposure. Additionally, phosphorous doping can also improve UV stability of photoluminescent Si NCs.

  2. Narrow, highly P-doped, planar wires in silicon created by scanning probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ruess, F J [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, NSW 2052 (Australia); Goh, K E J [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, NSW 2052 (Australia); Butcher, M J [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Reusch, T C G [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, NSW 2052 (Australia); Oberbeck, L [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, NSW 2052 (Australia); Weber, B [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Hamilton, A R [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Simmons, M Y [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, NSW 2052 (Australia)

    2007-01-31

    We demonstrate the use of a scanning tunnelling microscope (STM) to pattern buried, highly planar phosphorus-doped silicon wires with widths down to the sub-10 nm level. We confirm the structural integrity of these wires using both buried dopant imaging techniques and ex situ electrical characterization. Four terminal I-V characteristics at 4 K show ohmic behaviour for all wires with resistivities between 1 and 24 x 10{sup -8} {omega} cm. Magnetotransport measurements reveal that conduction is dominated by disordered scattering with quantum corrections consistent with 2D weak localization theory. Our results show that these quantum corrections become more pronounced as the electron phase coherence length approaches the width of the wire.

  3. X-ray diffraction studies of silicon implanted with high energy ions

    Energy Technology Data Exchange (ETDEWEB)

    Wieteska, K [Institute of Atomic Energy, Otwock-Swierk, (Poland); Wierzchowski, W [Institute of Electronic Materials Technology, Warsaw, (Poland); Graeff, W [Hasylab at Desy, Hamburg, (Germany)

    1997-12-31

    The character of lattice deformation in silicon in implanted with high energy {alpha} particles and protons was studied with a number of X-ray methods. The experiments included double crystal spectrometer method as well as single crystal section and projection topography realised both with conventional and synchrotron X-ray sources. All observed diffraction patterns were reasonably explainable assuming the lattice parameter depth distribution proportional to the vacancy-interstitial distribution coming from the Biersack-Ziegler theory. The theoretical rocking curves and density distribution in back-reflection double-crystal and section topography well corresponding to experimental results were calculated using numerical integration of the Takagi-Taupin equations. 9 figs.

  4. Status of the silicon strip high-rate FASTBUS readout system

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, H.; Barsotti, E.; Bowden, M.; Christian, D.; Chramowicz, J.; Fachin, M.; Haldeman, M.; Hoff, J.; Holmes, S.; Rotolo, C.; Romero, A.; Slimmer, D.; Swoboda, C.; Trendler, R.; Urish, J.; Yarema, R.; Zimmerman, T.; Zimmermann, S.; Kowald, W.; MacManus, A.; Recagni, M.; Segal, J.; Spentzouris, P.

    1991-11-01

    Our new readout system was developed in collaboration with, and largely to the specification of, the E771 experimenters. E771 is a fixed target experiment designed to study the production of B hadrons by an 800 GeV/c proton beam. The experiment will operate at rates of up to 200 million beam protons per second and 10 million interactions per second. The experimental apparatus will consist of an open geometry magnetic spectrometer featuring good muon and electron identification (much of which was used in E705), and a compact 16000 channel Silicon Strip Detector. In order to satisfy the experimenter's desire to instrument 16000 SSD elements in a package only 5 cm wide, 5 cm high, and 21 cm deep, and in order to meet the performance specifications, we have made extensive use of Application Specific Integrated Circuits'' (ASIC's).

  5. Highly conducting p-type nanocrystalline silicon thin films preparation without additional hydrogen dilution

    Science.gov (United States)

    Patra, Chandralina; Das, Debajyoti

    2018-04-01

    Boron doped nanocrystalline silicon thin film has been successfully prepared at a low substrate temperature (250 °C) in planar inductively coupled RF (13.56 MHz) plasma CVD, without any additional hydrogen dilution. The effect of B2H6 flow rate on structural and electrical properties of the films has been studied. The p-type nc-Si:H films prepared at 5 ≤ B2H6 (sccm) ≤ 20 retains considerable amount of nanocrystallites (˜80 %) with high conductivity ˜101 S cm-1 and dominant crystallographic orientation which has been correlated with the associated increased ultra- nanocrystalline component in the network. Such properties together make the material significantly effective for utilization as p-type emitter layer in heterojunction nc-Si solar cells.

  6. Lightweight and High-Resolution Single Crystal Silicon Optics for X-ray Astronomy

    Science.gov (United States)

    Zhang, William W.; Biskach, Michael P.; Chan, Kai-Wing; Mazzarella, James R.; McClelland, Ryan S.; Riveros, Raul E.; Saha, Timo T.; Solly, Peter M.

    2016-01-01

    We describe an approach to building mirror assemblies for next generation X-ray telescopes. It incorporates knowledge and lessons learned from building existing telescopes, including Chandra, XMM-Newton, Suzaku, and NuSTAR, as well as from our direct experience of the last 15 years developing mirror technology for the Constellation-X and International X-ray Observatory mission concepts. This approach combines single crystal silicon and precision polishing, thus has the potential of achieving the highest possible angular resolution with the least possible mass. Moreover, it is simple, consisting of several technical elements that can be developed independently in parallel. Lastly, it is highly amenable to mass production, therefore enabling the making of telescopes of very large photon collecting areas.

  7. Study of the photo-detection efficiency of FBK High-Density silicon photomultipliers

    International Nuclear Information System (INIS)

    Zappalà, G.; Regazzoni, V.; Acerbi, F.; Ferri, A.; Gola, A.; Paternoster, G.; Zorzi, N.; Piemonte, C.

    2016-01-01

    This work presents a study of the factors contributing to the Photo-Detection Efficiency of Silicon Photomultipliers (SiPMs): Quantum Efficiency, Triggering Probability and Fill Factor. Two different SiPM High-Density technologies are tested, NUV-HD, based on n-on-p junction, and RGB-HD, based on p-on-n junction, developed at FBK, Trento. The quantum efficiency was measured on photodiodes produced along with the SiPMs. The triggering probability, as a function of wavelength and bias voltage, was measured on circular Single Photon Avalanche Diodes (SPADs) with 100% fill factor. Square SPADs, having the same layout of single SiPM cells, were studied to measure the effective fill factor and compare it to the nominal value. The comparison of the circular and square SPADs allows to get the transition region size between the effective active area of the cell and the one defined by the layout.

  8. High-temperature effect of hydrogen on sintered alpha-silicon carbide

    Science.gov (United States)

    Hallum, G. W.; Herbell, T. P.

    1986-01-01

    Sintered alpha-silicon carbide was exposed to pure, dry hydrogen at high temperatures for times up to 500 hr. Weight loss and corrosion were seen after 50 hr at temperatures as low as 1000 C. Corrosion of SiC by hydrogen produced grain boundary deterioration at 1100 C and a mixture of grain and grain boundary deterioration at 1300 C. Statistically significant strength reductions were seen in samples exposed to hydrogen for times greater than 50 hr and temperatures above 1100 C. Critical fracture origins were identified by fractography as either general grain boundary corrision at 1100 C or as corrosion pits at 1300 C. A maximum strength decrease of approximately 33 percent was seen at 1100 and 1300 C after 500 hr exposure to hydrogen. A computer assisted thermodynamic program was also used to predict possible reaction species of SiC and hydrogen.

  9. Evanescently Coupled Rectangular Microresonators in Silicon-on-Insulator with High Q-Values: Experimental Characterization

    Directory of Open Access Journals (Sweden)

    Manuel Mendez-Astudillo

    2017-04-01

    Full Text Available We report on evanescently coupled rectangular microresonators with dimensions up to 20 × 10 μm2 in silicon-on-insulator in an add-drop filter configuration. The influence of the geometrical parameters of the device was experimentally characterized and a high Q value of 13,000 was demonstrated as well as the multimode optical resonance characteristics in the drop port. We also show a 95% energy transfer between ports when the device is operated in TM-polarization and determine the full symmetry of the device by using an eight-port configuration, allowing the drop waveguide to be placed on any of its sides, providing a way to filter and route optical signals. We used the FDTD method to analyze the device and e-beam lithography and dry etching techniques for fabrication.

  10. A monolithically integrated detector-preamplifier on high-resistivity silicon

    International Nuclear Information System (INIS)

    Holland, S.; Spieler, H.

    1990-02-01

    A monolithically integrated detector-preamplifier on high-resistivity silicon has been designed, fabricated and characterized. The detector is a fully depleted p-i-n diode and the preamplifier is implemented in a depletion-mode PMOS process which is compatible with detector processing. The amplifier is internally compensated and the measured gain-bandwidth product is 30 MHz with an input-referred noise of 15 nV/√Hz in the white noise regime. Measurements with an Am 241 radiation source yield an equivalent input noise charge of 800 electrons at 200 ns shaping time for a 1.4 mm 2 detector with on-chip amplifier in an experimental setup with substantial external pickup

  11. High photoconductive hydrogenated silicon by reactive sputtering in helium containing atmosphere

    International Nuclear Information System (INIS)

    Ohbiki, Tohru; Imura, Takeshi; Hiraki, Akio

    1982-01-01

    Mixed phase of amorphous and microcrystalline silicon-hydrogen alloys has been fabricated by reactive sputtering in He containing H 2 of which mole fraction is less than about 5 mole%. The degree of the crystallization, evaluated by electron microscopy and optical absorption spectroscopy, becomes high as the amount of H 2 in the atmosphere increases. The conductivity in dark and photoconductivity increase as the partial pressure of H 2 increases (form 0 to 1 mole%) and also as the pressure during sputtering increases. This increase in conductivity and photoconductivity is supposed to be related to the development of microcrystals. The highest photoconductivity is observed at the H 2 mole fraction of about 1 mole%. This film contains a small amount of microcrystals and show the photoconductivity higher by 2 orders of magnitude than that in a film sputter-deposited in Ar and H 2 atmosphere in the same apparatus. (author)

  12. High photoconductive hydrogenated silicon by reactive sputtering in helium containing atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Ohbiki, Tohru; Imura, Takeshi; Hiraki, Akio

    1982-08-01

    Mixed phase of amorphous and microcrystalline silicon-hydrogen alloys has been fabricated by reactive sputtering in He containing H/sub 2/ of which mole fraction is less than about 5 mole%. The degree of the crystallization, evaluated by electron microscopy and optical absorption spectroscopy, becomes high as the amount of H/sub 2/ in the atmosphere increases. The conductivity in dark and photoconductivity increase as the partial pressure of H/sub 2/ increases (form 0 to 1 mole%) and also as the pressure during sputtering increases. This increase in conductivity and photoconductivity is supposed to be related to the development of microcrystals. The highest photoconductivity is observed at the H/sub 2/ mole fraction of about 1 mole%. This film contains a small amount of microcrystals and show the photoconductivity higher by 2 orders of magnitude than that in a film sputter-deposited in Ar and H/sub 2/ atmosphere in the same apparatus.

  13. Comparative study on electrical properties of atomic layer deposited high-permittivity materials on silicon substrates

    International Nuclear Information System (INIS)

    Duenas, S.; Castan, H.; Garcia, H.; Barbolla, J.; Kukli, K.; Ritala, M.; Leskelae, M.

    2005-01-01

    Deep level transient spectroscopy, capacitance-voltage and conductance transient measurement techniques have been applied in order to evaluate the electrical quality of thin high-permittivity oxide layers on silicon. The oxides studied included HfO 2 film grown from two different oxygen-free metal precursors and Ta 2 O 5 and Nb 2 O 5 nanolaminates. The interface trap densities correlated to the oxide growth chemistry and semiconductor substrate treatment. No gap state densities induced by structural disorder were measured in the films grown on chemical SiO 2 . Trap densities were also clearly lower in HfO 2 films compared to Ta 2 O 5 -Nb 2 O 5

  14. Status of the silicon strip high-rate FASTBUS readout system

    International Nuclear Information System (INIS)

    Gonzalez, H.; Barsotti, E.; Bowden, M.; Christian, D.; Chramowicz, J.; Fachin, M.; Haldeman, M.; Hoff, J.; Holmes, S.; Rotolo, C.; Romero, A.; Slimmer, D.; Swoboda, C.; Trendler, R.; Urish, J.; Yarema, R.; Zimmerman, T.; Zimmermann, S.; Kowald, W.; MacManus, A.; Recagni, M.; Segal, J.; Spentzouris, P.

    1991-11-01

    Our new readout system was developed in collaboration with, and largely to the specification of, the E771 experimenters. E771 is a fixed target experiment designed to study the production of B hadrons by an 800 GeV/c proton beam. The experiment will operate at rates of up to 200 million beam protons per second and 10 million interactions per second. The experimental apparatus will consist of an open geometry magnetic spectrometer featuring good muon and electron identification (much of which was used in E705), and a compact 16000 channel Silicon Strip Detector. In order to satisfy the experimenter's desire to instrument 16000 SSD elements in a package only 5 cm wide, 5 cm high, and 21 cm deep, and in order to meet the performance specifications, we have made extensive use of ''Application Specific Integrated Circuits'' (ASIC's)

  15. Numerical quantification and minimization of perimeter losses in high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Altermatt, P.P.; Heiser, Gernot; Green, M.A. [New South Wales Univ., Kensington, NSW (Australia)

    1996-09-01

    This paper presents a quantitative analysis of perimeter losses in high-efficiency silicon solar cells. A new method of numerical modelling is used, which provides the means to simulate a full-sized solar cell, including its perimeter region. We analyse the reduction in efficiency due to perimeter losses as a function of the distance between the active cell area and the cut edge. It is shown how the optimum distance depends on whether the cells in the panel are shingled or not. The simulations also indicate that passivating the cut-face with a thermal oxide does not increase cell efficiency substantially. Therefore, doping schemes for the perimeter domain are suggested in order to increase efficiency levels above present standards. Finally, perimeter effects in cells that remain embedded in the wafer during the efficiency measurement are outlined. (author)

  16. Evaluation of the characteristics of high burnup and high plutonium content mixed oxide (MOX) fuel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    Two kinds of MOX fuel irradiation tests, i.e., MOX irradiation test up to high burnup and MOX having high plutonium content irradiation test, have been performed from JFY 2007 for five years in order to establish technical data concerning MOX fuel behavior during irradiation, which shall be needed in safety regulation of MOX fuel with high reliability. The high burnup MOX irradiation test consists of irradiation extension and post irradiation examination (PIE). The activities done in JFY 2011 are destructive post irradiation examination (D-PIE) such as EPMA and SIMS at CEA (Commissariat a l'Enegie Atomique) facility. Cadarache and PIE data analysis. In the frame of irradiation test of high plutonium content MOX fuel programme, MOX fuel rods with about 14wt % Pu content are being irradiated at BR-2 reactor and corresponding PIE is also being done at PIE facility (SCK/CEN: Studiecentrum voor Kernenergie/Centre d'Etude l'Energie Nucleaire) in Belgium. The activities done in JFY 2011 are non-destructive post irradiation examination (ND-PIE) and D-PIE and PIE data analysis. In this report the results of EPMA and SIMS with high burnup irradiation test and the result of gamma spectrometry measurement which can give FP gas release rate are reported. (author)

  17. Radiation hardness and precision timing study of silicon detectors for the CMS High Granularity Calorimeter (HGC)

    Energy Technology Data Exchange (ETDEWEB)

    Currás, Esteban, E-mail: ecurrasr@cern.ch [CERN, Organisation europnne pour la recherche nucleaire, CH-1211 Genéve 23 (Switzerland); Instituto de Física de Cantabria (CSIC-UC), Avda. los Castros s/n, E-39005 Santander (Spain); Fernández, Marcos [Instituto de Física de Cantabria (CSIC-UC), Avda. los Castros s/n, E-39005 Santander (Spain); Gallrapp, Christian [CERN, Organisation europnne pour la recherche nucleaire, CH-1211 Genéve 23 (Switzerland); Gray, Lindsey [Fermilab, Wilson Street and Kirk Road, Batavia, IL 60510-5011, Illinois (United States); Mannelli, Marcello [CERN, Organisation europnne pour la recherche nucleaire, CH-1211 Genéve 23 (Switzerland); Meridiani, Paolo [Istituto Nazionale Di Fisica Nucleare – Sezione di Roma, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Moll, Michael [CERN, Organisation europnne pour la recherche nucleaire, CH-1211 Genéve 23 (Switzerland); Nourbakhsh, Shervin [University of Minnesota, Minneapolis, MN 55455 (United States); Scharf, Christian [Hamburg University, Notkestraße 85, 22607 Hamburg (Germany); Silva, Pedro [CERN, Organisation europnne pour la recherche nucleaire, CH-1211 Genéve 23 (Switzerland); Steinbrueck, Georg [Hamburg University, Notkestraße 85, 22607 Hamburg (Germany); Fatis, Tommaso Tabarelli de [Istituto Nazionale di Fisica Nucleare – Sezione di Milano-Bicocca Piazza della Scienza 3, 20126 Milano (Italy); Vila, Iván [Instituto de Física de Cantabria (CSIC-UC), Avda. los Castros s/n, E-39005 Santander (Spain)

    2017-02-11

    The high luminosity upgraded LHC or Phase-II is expected to increase the instantaneous luminosity by a factor of 10 beyond the LHC's design value, expecting to deliver 250 fb{sup −1} per year for a further 10 years of operation. Under these conditions the performance degradation due to integrated radiation dose will need to be addressed. The CMS collaboration is planning to upgrade the forward calorimeters. The replacement is called the High Granularity Calorimeter (HGC) and it will be realized as a sampling calorimeter with layers of silicon detectors interleaved. The sensors will be realized as pad detectors with sizes of less that ∼1.0 cm{sup 2} and an active thickness between 100 and 300 μm depending on the position, respectively, the expected radiation levels. For an integrated luminosity of 3000 fb{sup −1}, the electromagnetic calorimetry will sustain integrated doses of 1.5 MGy (150 Mrads) and neutron fluences up to 10{sup 16} neq/cm{sup 2}. A radiation tolerance study after neutron irradiation of 300, 200, and 100 μm n-on-p and p-on-n silicon pads irradiated to fluences up to 1.6×10{sup 16} neq/cm{sup 2} is presented. The properties of these diodes studied before and after irradiation were leakage current, capacitance, charge collection efficiency, annealing effects and timing capability. The results of these measurements validate these sensors as candidates for the HGC system.

  18. Effects of DC bias on magnetic performance of high grades grain-oriented silicon steels

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Guang; Cheng, Ling [Global Energy Interconnection Research Institute, State Key Laboratory of Advanced Transmission Technology,Beijing 102211 (China); Lu, Licheng [State Grid Corporation of China, Beijing 100031 (China); Yang, Fuyao; Chen, Xin [Global Energy Interconnection Research Institute, State Key Laboratory of Advanced Transmission Technology,Beijing 102211 (China); Zhu, Chengzhi [State Grid Zhejiang Electric Power Company, Hangzhou 310007 (China)

    2017-03-15

    When high voltage direct current (HVDC) transmission adopting mono-polar ground return operation mode or unbalanced bipolar operation mode, the invasion of DC current into neutral point of alternating current (AC) transformer will cause core saturation, temperature increasing, and vibration acceleration. Based on the MPG-200D soft magnetic measurement system, the influence of DC bias on magnetic performance of 0.23 mm and 0.27 mm series (P{sub 1.7}=0.70–1.05 W/kg, B{sub 8}>1.89 T) grain-oriented (GO) silicon steels under condition of AC / DC hybrid excitation were systematically realized in this paper. For the high magnetic induction GO steels (core losses are the same), greater thickness can lead to stronger ability of resisting DC bias, and the reasons for it were analyzed. Finally, the magnetostriction and A-weighted magnetostriction velocity level of GO steel under DC biased magnetization were researched. - Highlights: • Magnetic properties of 0.23 mm and 0.27 mm series (P{sub 1.7}=0.70–1.05 W/kg, B{sub 8}>1.89 T) grain-oriented (GO) silicon steels under condition of AC / DC hybrid excitation were systematically analyzed. • Influence of DC biased magnetization on core loss, magnetostriction, and A-weighted magnetostriction velocity level of GO steel were researched. • Greater thickness and relatively lower magnetic induction (B{sub 8}>1.89 T yet) of GO steel can lead to stronger ability of resisting DC bias, and the reasons for it were analyzed.

  19. Corrosion resistance testing of high-boron-content stainless steels

    International Nuclear Information System (INIS)

    Petrman, I.; Safek, V.

    1994-01-01

    Boron steels, i.e. stainless steels with boron contents of 0.2 to 2.25 wt.%, are employed in nuclear engineering for the manufacture of baskets or wells in which radioactive fissile materials are stored, mostly spent nuclear fuel elements. The resistance of such steels to intergranular corrosion and uniform corrosion was examined in the Strauss solution and in boric acid; the dependence of the corrosion rate of the steels on their chemical composition was investigated, and their resistance was compared with that of AISI 304 type steel. Corrosion resistance tests in actual conditions of ''wet'' compact storage (demineralized water or a weak boric acid solution) gave evidence that boron steels undergo nearly no uniform corrosion and, as electrochemical measurements indicated, match standard corrosion-resistant steels. Corrosion resistance was confirmed to decrease slightly with increasing boron content and to increase somewhat with increasing molybdenum content. (Z.S.). 3 tabs., 4 figs., 7 refs

  20. Improvement in IBC-silicon solar cell performance by insertion of highly doped crystalline layer at heterojunction interfaces

    International Nuclear Information System (INIS)

    Bashiri, Hadi; Azim Karami, Mohammad; Mohammadnejad, Shahramm

    2017-01-01

    By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact (IBC) silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters (doping concentration and thickness) is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of 2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si:H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density. (paper)