WorldWideScience

Sample records for bulk semiconductor detectors

  1. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  2. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  3. Fundamental properties of semiconductor materials, and material performance in detectors

    Science.gov (United States)

    Casper, K. J.

    1973-01-01

    Procedures for determining fundamental properties of semiconductor materials, their performance as radiation detectors, and their service life as such detectors are given. Relationships were established between the minority carrier lifetime in the bulk of the material and the charge collection efficiency of the detector.

  4. Modelling semiconductor pixel detectors

    CERN Document Server

    Mathieson, K

    2001-01-01

    expected after 200 ps in most cases. The effect of reducing the charge carrier lifetime and examining the charge collection efficiency has been utilised to explore how these detectors would respond in a harsh radiation environment. It is predicted that over critical carrier lifetimes (10 ps to 0.1 ns) an improvement of 40 % over conventional detectors can be expected. This also has positive implications for fabricating detectors, in this geometry, from materials which might otherwise be considered substandard. An analysis of charge transport in CdZnTe pixel detectors has been performed. The analysis starts with simulation studies into the formation of contacts and their influence on the internal electric field of planar detectors. The models include a number of well known defect states and these are balanced to give an agreement with a typical experimental I-V curve. The charge transport study extends to the development of a method for studying the effect of charge sharing in highly pixellated detectors. The ...

  5. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  6. Hybrid anode for semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

    2013-11-19

    The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).

  7. Wafer-fused semiconductor radiation detector

    Science.gov (United States)

    Lee, Edwin Y.; James, Ralph B.

    2002-01-01

    Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

  8. Bulk Rashba Semiconductors and Related Quantum Phenomena.

    Science.gov (United States)

    Bahramy, Mohammad Saeed; Ogawa, Naoki

    2017-03-29

    Bithmuth tellurohalides BiTeX (X = Cl, Br and I) are model examples of bulk Rashba semiconductors, exhibiting a giant Rashba-type spin splitting among their both valence and conduction bands. Extensive spectroscopic and transport experiments combined with the state-of-the-art first-principles calculations have revealed many unique quantum phenomena emerging from the bulk Rashba effect in these systems. The novel features such as the exotic inter- and intra-band optical transitions, enhanced magneto-optical response, divergent orbital dia-/para-magnetic susceptibility and helical spin textures with a nontrivial Berry's phase in the momentum space are among the salient discoveries, all arising from this effect. Also, it is theoretically proposed and indications have been experimentally reported that bulk Rashba semiconductors such as BiTeI have the capability of becoming a topological insulator under the application of a hydrostatic pressure. Here, we overview these studies and show that BiTeX are an ideal platform to explore the next aspects of quantum matter, which could ultimately be utilized to create spintronic devices with novel functionalities.

  9. Semiconductor High-Energy Radiation Scintillation Detector

    CERN Document Server

    Kastalsky, A; Spivak, B

    2006-01-01

    We propose a new scintillation-type detector in which high-energy radiation produces electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. The most important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombi...

  10. Modeling direct interband tunneling. I. Bulk semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Andrew, E-mail: pandrew@ucla.edu [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); Chui, Chi On [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2014-08-07

    Interband tunneling is frequently studied using the semiclassical Kane model, despite uncertainty about its validity. Revisiting the physical basis of this formula, we find that it neglects coupling to other bands and underestimates transverse tunneling. As a result, significant errors can arise at low and high fields for small and large gap materials, respectively. We derive a simple multiband tunneling model to correct these defects analytically without arbitrary parameters. Through extensive comparison with band structure and quantum transport calculations for bulk InGaAs, InAs, and InSb, we probe the accuracy of the Kane and multiband formulas and establish the superiority of the latter. We also show that the nonlocal average electric field should be used when applying either of these models to nonuniform potentials. Our findings are important for efficient analysis and simulation of bulk semiconductor devices involving tunneling.

  11. New materials for radiation hard semiconductor detectors

    CERN Document Server

    Sellin, P J; CERN. Geneva

    2006-01-01

    We present a review of the current status of research into new semiconductor materials for use as particle tracking detectors in very high radiation environments. This work is carried out within the framework of the CERN RD50 collaboration, which is investigating detector technologies suitable for operation at the proposed Super-LHC facility (SLHC). Tracking detectors operating at the SLHC in this environment will have to be capable of withstanding radiation levels arising from a luminosity of 1035 cm-2s-1 which will present severe challenges to current tracking detector technologies. The "new materials" activity within RD50 is investigating the performance of various semiconductor materials that potentially offer radiation hard alternatives to silicon devices. The main contenders in this study are silicon carbide, gallium nitride and amorphous silicon. In this paper we review the current status of these materials, in terms of material quality, commercial availability, charge transport properties, and radiati...

  12. Semiconductor detectors in the low countries

    CERN Document Server

    Heijne, Erik H M

    2003-01-01

    Several milestones in the development of semiconductor radiation imaging detectors are attributed to scientists from the Low Countries, the Netherlands and Belgium, and a few historical details will be highlighted. The very first usable semiconductor nuclear detector was made in Utrecht, around 1943, in the form of an AgCl crystal. The earliest large-scale application of monolithic, double- sided silicon strip detectors was in the BOL experiment around 1968 at IKO, now NIKHEF, in Amsterdam. The technology developed and patented by Philips and IKO was adapted by the author and coworkers in 1980 to produce the first silicon microstrip detector used for the reconstruction of events in a CERN fixed target experiment. An avalanche of developments then led to worldwide use of silicon microstrip detectors in elementary particle physics, motivated by the capability to reconstruct particles with lifetime similar to 10**- **1**2s, which decay on sub-millimeter scale. The intensive activity in silicon detector R&D c...

  13. Development of Large Cryogenic Semiconductor Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mandic, Vuk [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-12-09

    This project aims at developing large cryogenic semiconductor detectors for applications in particle physics and more broadly. We have developed a 150 mm diameter, 43 mm thick, Si-based detector that measures ionization released in an interaction of a particle inside the silicon crystal of high purity, operated at 30 mK temperature. We demonstrated that such a detector can be used to measure recoil energies on the keV scale, and that its stable operation can be maintained indefinitely. Detectors of this type could therefore be used in the fields of direct dark matter searches, coherent neutrino scattering measurements, X-ray observations, as well as in broader applications such as homeland security.

  14. Modeling and simulation of bulk gallium nitride power semiconductor devices

    Directory of Open Access Journals (Sweden)

    G. Sabui

    2016-05-01

    Full Text Available Bulk gallium nitride (GaN power semiconductor devices are gaining significant interest in recent years, creating the need for technology computer aided design (TCAD simulation to accurately model and optimize these devices. This paper comprehensively reviews and compares different GaN physical models and model parameters in the literature, and discusses the appropriate selection of these models and parameters for TCAD simulation. 2-D drift-diffusion semi-classical simulation is carried out for 2.6 kV and 3.7 kV bulk GaN vertical PN diodes. The simulated forward current-voltage and reverse breakdown characteristics are in good agreement with the measurement data even over a wide temperature range.

  15. Detection of Berry's phase in a Bulk Rashba semiconductor.

    Science.gov (United States)

    Murakawa, H; Bahramy, M S; Tokunaga, M; Kohama, Y; Bell, C; Kaneko, Y; Nagaosa, N; Hwang, H Y; Tokura, Y

    2013-12-20

    The motion of electrons in a solid has a profound effect on its topological properties and may result in a nonzero Berry's phase, a geometric quantum phase encoded in the system's electronic wave function. Despite its ubiquity, there are few experimental observations of Berry's phase of bulk states. Here, we report detection of a nontrivial π Berry's phase in the bulk Rashba semiconductor BiTeI via analysis of the Shubnikov-de Haas (SdH) effect. The extremely large Rashba splitting in this material enables the separation of SdH oscillations, stemming from the spin-split inner and outer Fermi surfaces. For both Fermi surfaces, we observe a systematic π-phase shift in SdH oscillations, consistent with the theoretically predicted nontrivial π Berry's phase in Rashba systems.

  16. Design and Fabrication of Silicon Carbide Semiconductor Detectors

    Institute of Scientific and Technical Information of China (English)

    MENG; Xin; LIU; Yang; HE; Gao-kui

    2015-01-01

    The potential of silicon carbide(SiC)for use in semiconductor nuclear radiation detectors has been recognized for years.SiC detectors have now been demonstrated for high-resolution alpha particle and X-ray energy spectrometry,beta ray,gamma-ray,thermal-and fast-neutron

  17. Charge induction in semiconductor detectors with pixellated structure

    NARCIS (Netherlands)

    Samedov, Victor V.

    2007-01-01

    Considerable interest is now being attracted to the next generation of compound semiconductor detectors with pixellated structure in application to x-ray and gamma-astronomy, nuclear spectroscopy and nuclear medicine. The spatial resolution of this type of detectors is mainly determined by the proce

  18. Integrated superconducting detectors on semiconductors for quantum optics applications

    Science.gov (United States)

    Kaniber, M.; Flassig, F.; Reithmaier, G.; Gross, R.; Finley, J. J.

    2016-05-01

    Semiconductor quantum photonic circuits can be used to efficiently generate, manipulate, route and exploit nonclassical states of light for distributed photon-based quantum information technologies. In this article, we review our recent achievements on the growth, nanofabrication and integration of high-quality, superconducting niobium nitride thin films on optically active, semiconducting GaAs substrates and their patterning to realize highly efficient and ultra-fast superconducting detectors on semiconductor nanomaterials containing quantum dots. Our state-of-the-art detectors reach external detection quantum efficiencies up to 20 % for ~4 nm thin films and single-photon timing resolutions <72 ps. We discuss the integration of such detectors into quantum dot-loaded, semiconductor ridge waveguides, resulting in the on-chip, time-resolved detection of quantum dot luminescence. Furthermore, a prototype quantum optical circuit is demonstrated that enabled the on-chip generation of resonance fluorescence from an individual InGaAs quantum dot, with a linewidth <15 μeV displaced by 1 mm from the superconducting detector on the very same semiconductor chip. Thus, all key components required for prototype quantum photonic circuits with sources, optical components and detectors on the same chip are reported.

  19. Method for mapping charge pulses in semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Prettyman, T.H.

    1998-12-01

    An efficient method for determining the distribution of charge pulses produced by semiconductor detectors is presented. The method is based on a quasi-steady-state model for semiconductor detector operation. A complete description of the model and underlying assumptions is given. Mapping of charge pulses is accomplished by solving an adjoint carrier continuity equation. The solution of the adjoint equation yields Green`s function, a time- and position-dependent map that contains all possible charge pulses that can be produced by the detector for charge generated at discrete locations (e.g., by gamma-ray interactions). Because the map is generated by solving a single, time-dependent problem, the potential for reduction in computational effort over direct mapping methods is significant, particularly for detectors with complex electrode structures. In this paper, the adjoint equation is derived and the mapping method is illustrated for a simple case.

  20. Current responsivity of semiconductor superlattice THz-photon detectors

    DEFF Research Database (Denmark)

    Ignatov, Anatoly A.; Jauho, Antti-Pekka

    1999-01-01

    The current responsivity of a semiconductor superlattice THz-photon detector is calculated using an equivalent circuit model which takes into account the finite matching efficiency between a detector antenna and the superlattice in the presence of parasitic losses. Calculations performed for curr......The current responsivity of a semiconductor superlattice THz-photon detector is calculated using an equivalent circuit model which takes into account the finite matching efficiency between a detector antenna and the superlattice in the presence of parasitic losses. Calculations performed...... for currently available superlattice diodes show that both the magnitudes and the roll-off frequencies of the responsivity are strongly influenced by an excitation of hybrid plasma-Bloch oscillations which are found to be eigenmodes of the system in the THz-frequency band. The expected room temperature values...

  1. Investigation of Ion Backflow in Bulk Micromegas Detectors

    CERN Document Server

    Bhattacharya, Purba; Mukhopadhyay, Supratik; Bhattacharya, Sudeb; Majumdar, Nayana; Sarkar, Sandip; Colas, Paul; Attie, David

    2016-01-01

    The operation of gas detectors is often limited by secondary effects, originating from avalanche-induced photons and ions. Ion backflow is one of the effects limiting the operation of a gas detector at high flux, by giving rise to space charge which disturbs the electric field locally. For the Micromegas detector, a large fraction of the secondary positive ions created in the avalanche can be stopped at the micro-mesh. The present work involves measurements of the ion backflow fraction (using an experimental setup comprising of two drift planes) in bulk Micromegas detectors as a function of detector design parameters. These measured characteristics have also been compared in detail to numerical simulations using the Garfield framework that combines packages such as neBEM, Magboltz and Heed. Further, the effect of using a second micro-mesh on ion backflow and other parameters has been studied numerically.

  2. Evaluation of mercuric iodide ceramic semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M.; Zuck, A.; Braiman, M.; Nissenbaum, J. [Hebrew Univ., Jerusalem (Israel); Turchetta, R.; Dulinski, W.; Husson, D.; Riester, J.L. [LEPSI (ULP/IN2P3), Strasbourg (France)

    1998-02-01

    Mercuric iodide ceramic radiation detectors, which can act as nuclear particle counters, have been fabricated with single continuos electrical contacts and with linear strip contacts. They have been tested with different kinds of {gamma} and {beta} sources as well as in a high energy beam at CERN. The detectors were also successfully tested for radiation hardness with irradiation of 5*10{sup 14} neutrons/cm{sup 2}. The ratio of detected photons over the number of absorbed photons has been measured with {gamma} sources of different energies, and it ranges from 20% at 44 keV up to about 30% at 660 keV. An absolute efficiency of 70% has been measured for a 350 {mu}m thick detector for {beta} particles emitted by a {sup 90}Sr source. Charge collection efficiency, defined as the amount of charge induced on the electrodes by a mminimum ionizing particle (MIP) traversing the detector, has been measured in two samples. The average collected charge fits well with a linear curve with slope of 35 electrons/(kV/cm) per 100 {mu}m. This result is well described by a dynamic device simulation, where the free carrier mean lifetime is used as a free parameter, adjusted to a value of 1.5 ns, i.e. about 1/100 of the corresponding lifetime in single crystal HgI{sub 2} detectors. The response to MIP has also been studied with a high energy (100 GeV) muon beam in CERN. A preliminary beam profile is presented while a more detailed analysis is still in progress and will be presented elsewhere. These results together with the low cost of the material make ceramic HgI{sub 2} detectors excellent candidates for large area particle tracking and imaging applications, even in a radiation harsh environment. (orig.). 14 refs.

  3. 11th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors

    CERN Document Server

    2013-01-01

    The conference will focus on semiconductor detectors issues relevant to applications in accelerator and space research. Topics include: - large semiconductor systems for calorimetry and tracking applications; - radiation damage measurements and modeling; - radiation hardness of semiconductor detectors; - innovative detectors and electronic systems.

  4. Semiconductors for room temperature nuclear detector applications

    CERN Document Server

    James, Ralph B

    1995-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The""Willardson and Beer""Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series.

  5. Semiconductor detectors for soft γ-ray astrophysics

    Science.gov (United States)

    Lebrun, François

    2006-07-01

    The study of γ-ray bursts, compact objects, nucleosynthesis and supernova remnants triggers the most interest today in the soft γ-ray domain. These topics have various experimental requirements with emphasis either on imaging or on spectroscopy. Recent progress has shown the great potential of semiconductor detectors for both applications at the expense of classical scintillators such as NaI or CsI. They also gave insight into their long-term in-orbit behaviour. Room temperature semiconductor detectors, particularly CdTe and CdZnTe, are confirmed as the best choice for imaging applications. As illustrated by the INTEGRAL/ISGRI camera, the CdTe stability is better than expected; its internal background is comparable to that of scintillators, and the spectroscopic degradation in space is slow with a lifetime of about 40 years on an eccentric orbit. Cooled germanium detectors offer the best energy resolution but degrade more rapidly under the cosmic-ray irradiation. However, the INTEGRAL/SPI spectrometer has demonstrated that periodic in-orbit annealings, allowing for a full recovery of the energy resolution, can maintain the spectroscopic performance over several years. Most future projects, focussing on coded mask or Compton telescopes, will take advantage of the semiconductor technology, particularly that related to the ambient temperature detectors.

  6. An investigation of performance characteristics of a pixellated room-temperature semiconductor detector for medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, P; Santos, A [Centro de Investigacion Biomedica de Bioningenieria, Biomateriales y Nanomedicina, CEEI-Modulo 3, C/ Maria de Luna, 11, 50018 Zaragoza (United States); Darambara, D G, E-mail: pguerra@ciber-bbn.e [Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Fulham Road, London SW3 6JJ (United Kingdom)

    2009-09-07

    The operation of any semiconductor detector depends on the movement of the charge carriers, which are created within the material when radiation passes through, as a result of energy deposition. The carrier movement in the bulk semiconductor induces charges on the metal electrodes, and therefore a current on the electrodes and the external circuit. The induced charge strongly depends on the material transport parameters as well as the geometrical dimensions of a pixellated semiconductor detector. This work focuses on the performance optimization in terms of energy resolution, detection efficiency and intrinsic spatial resolution of a room-temperature semiconductor pixellated detector based on CdTe/CdZnTe. It analyses and inter-relates these performance figures for various dimensions of CdTe and CdZnTe detectors and for an energy range spanning from x-ray (25 keV) to PET (511 keV) imaging. Monte Carlo simulations, which integrate a detailed and accurate noise model, are carried out to investigate several CdTe/CdZnTe configurations and to determine possible design specifications. Under the considered conditions, the simulations demonstrate the superiority of the CdZnTe over the CdTe in terms of energy resolution and sensitivity in the photopeak. Further, according to the results, the spatial resolution is maximized at high energies and the energy resolution at low energies, while a reasonable detection efficiency is achieved at high energies, with a 1 x 1 x 6 mm{sup 3} CdZnTe pixellated detector.

  7. Dispersion regions overlapping for bulk and surface polaritons in a magnetic-semiconductor superlattice

    CERN Document Server

    Fesenko, Volodymyr I; Tuz, Vladimir R

    2016-01-01

    Extraordinary dispersion features of both bulk and surface polaritons in a finely-stratified magnetic-semiconductor structure which is under an action of an external static magnetic field in the Voigt geometry are discussed in this letter. It is shown that the conditions for total overlapping dispersion regions of simultaneous existence of bulk and surface polaritons can be reached providing a conscious choice of the constitutive parameters and material fractions for both magnetic and semiconductor subsystems.

  8. Radiation-hard semiconductor detectors for SuperLHC

    CERN Document Server

    Bruzzi, Mara; Al-Ajili, A A; Alexandrov, P; Alfieri, G; Allport, Philip P; Andreazza, A; Artuso, M; Assouak, S; Avset, B S; Barabash, L; Baranova, E; Barcz, A; Basile, A; Bates, R; Belova, N; Betta, G F D; Biagi, S F; Bilei, G M; Bisello, D; Blue, A; Blumenau, A; Boisvert, V; Bölla, G; Bondarenko, G B; Borchi, E; Borrello, L; Bortoletto, D; Boscardin, M; Bosisio, L; Bowcock, T J V; Brodbeck, T J; Broz, J; Brukhanov, A; Brzozowski, A; Buda, M; Buhmann, P; Buttar, C; Campabadal, F; Campbell, D; Candelori, A; Casse, G; Cavallini, A; Chilingarov, A G; Chren, D; Cindro, V; Citterio, M; Collins, P; Coluccia, R; Contarato, D; Coutinho, J; Creanza, D; Cunningham, W; Cvetkov, V; Davies, G; Dawson, I; De Palma, M; Demina, R; Dervan, P; Dierlamm, A; Dittongo, S; Dobrzanski, L; Dolezal, Z; Dolgolenko, A; Eberlein, T; Eremin, V; Fall, C; Fasolo, F; Ferbel, T; Fizzotti, F; Fleta, C; Focardi, E; Forton, E; Franchenko, S; Fretwurst, E; Gamaz, F; García-Navarro, J E; García, C; Gaubas, E; Genest, M H; Gill, K A; Giolo, K; Glaser, M; Gössling, C; Golovine, V; Gorelov, I; Goss, J; Gouldwell, A; Grégoire, G; Gregori, P; Grigoriev, E; Grigson, C; Grillo, A; Groza, A; Guskov, J; Haddad, L; Harding, R; Härkönen, J; Hauler, F; Hayama, S; Hoeferkamp, M; Honniger, F; Horazdovsky, T; Horisberger, R P; Horn, M; Houdayer, A; Hourahine, B; Hruban, A; Hughes, G; Ilyashenko, Yu S; Irmscher, K; Ivanov, A; Jarasiunas, K; Jin, T; Jones, B K; Jones, R; Joram, C; Jungermann, L; Kalinina, E; Kaminski, P; Karpenko, A; Karpov, A; Kazlauskiene, V; Kazukauskas, V; Khivrich, V; Khomenkov, V P; Kierstead, J A; Klaiber Lodewigs, J M; Kleverman, M; Klingenberg, R; Kodys, P; Kohout, Z; Korjenevski, S; Kowalik, A; Kozlowski, R; Kozodaev, M; Kramberger, G; Krasel, O; Kuznetsov, A; Kwan, S; Lagomarsino, S; Lari, T; Lassila-Perini, K M; Lastovetsky, V F; Latino, G; Latushkin, S T; Lazanu, I; Lazanu, S; Lebel, C; Leinonen, K; Leroy, C; Li, Z; Lindström, G; Lindström, L; Linhart, V; Litovchenko, A P; Litovchenko, P G; Litvinov, V; Lo Giudice, A; Lozano, M; Luczynski, Z; Luukka, Panja; Macchiolo, A; Mainwood, A; Makarenko, L F; Mandic, I; Manfredotti, C; Martí i García, S; Marunko, S; Mathieson, K; Melone, J; Menichelli, D; Meroni, C; Messineo, A; Miglio, S; Mikuz, M; Miyamoto, J; Moll, M; Monakhov, E; Moscatelli, F; Mozzanti, A; Murin, L; Naoumov, D; Nava, F; Nossarzhevska, E; Nummela, S; Nysten, J; Olivero, P; O'Shea, V; Palviainen, T; Paolini, C; Parkes, C; Passeri, D; Pein, U; Pellegrini, G; Perera, L; Petasecca, M; Piatkowski, B; Piemonte, C; Pignatel, G U; Pinho, N; Pintilie, I; Pintilie, L; Polivtsev, L; Polozov, P; Popa, A I; Popule, J; Pospísil, S; Pucker, G; Radicci, V; Rafí, J M; Ragusa, F; Rahman, M; Rando, R; Röder, R; Rohe, T; Ronchin, S; Rott, C; Roy, A; Roy, P; Ruzin, A; Ryazanov, A; Sadrozinski, H F W; Sakalauskas, S; Scaringella, M; Schiavulli, L; Schnetzer, S; Schumm, B; Sciortino, S; Scorzoni, A; Segneri, G; Seidel, S; Seiden, A; Sellberg, G; Sellin, P J; Sentenac, D; Sevilla, S G; Shipsey, I; Sícho, P; Sloan, T; Solar, M; Son, S; Sopko, B; Spencer, N; Stahl, J; Stavitski, I; Stolze, D; Stone, R; Storasta, J; Strokan, N; Strupinski, W; Sudzius, M; Surma, B; Suuronen, J; Suvorov, A; Svensson, B G; Tipton, P; Tomasek, M; Troncon, C; Tsvetkov, A; Tuominen, E; Tuovinen, E; Tuuva, T; Tylchin, M; Uebersee, H; Uher, J; Ullán, M; Vaitkus, J V; Vanni, P; Velthuis, J; Verbitskaya, E; Verzellesi, G; Vrba, V; Wagner, G; Wilhelm, I; Worm, S; Wright, V; Wunstorf, R; Zabierowski, P; Zaluzhny, A; Zavrtanik, M; Zen, M; Zhukov, V; Zorzi, N; de Boer, Wim

    2005-01-01

    An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 10/sup 35/ cm-/sup 2/s-/sup 1/ has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 10 /sup 16/ cm-/sup 2/. The CERN-RD50 project "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" has been established in 2002 to explore detector materials and technologies that will allow to operate devices up to, or beyond, this limit. The strategies followed by RD50 to enhance the radiation tolerance include the development of new or defect engineered detector materials (SiC, GaN, Czochralski and epitaxial silicon, oxygen enriched Flo...

  9. Detection Simulation of SiC Semiconductor Detector

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong Yeop; Kim, Jeong Dong; Lee, Yong Deok; Kim, Ho Dong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In a high radiation environment, it has received attention as a material for detecting radiation (neutron). As the field of application of a SIC neutron detector, the semiconductor detector used in cosmic rays was proposed by Ruddy. Recently, X-ray and low-energy gamma ray spectrometry with SiC detectors has been reported. Its usability has recently been being proved in neutron dose surveillance in BNCT (Boron-Capture Neutron Therapy), thermal neutron detection in a waste drum, nuclear material surveillance, and fast neutron detection. In addition, in 2006, an experiment was actually performed by Natsume on spent nuclear fuel. SIC is suitable for radiation surveillance in a complex radiation field emitted from spent nuclear fuel and the pyropocess process. In the radiation field of spent nuclear fuel, neutrons and gamma rays are generated. In this research, the performance of a SiC detector made at KAERI was evaluated to obtain a discriminated neutron signal. First, using neutron ({sup 252}Cf), alpha ({sup 241}Am), and gamma ({sup 60}Co) sources, a SiC semi- conductor detector was tested. The energy spectrum in a complex radiation field was simulated using the MCNPX 2.5. Finally, the experimental results by Ruddy were compared with the simulation results. Research result, whether the SiC semiconductor detector operating or not was confirmed through the simulation according to the neutron, gamma. The simulation results were similar to those of Ruddy. A further study is underway to investigate the discriminated neutron signal of a complex radiation field.

  10. A semiconductor parameter analyzer for ionizing radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luiz A.P., E-mail: lasantos@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2009-07-01

    Electrometers and ion chamber are normally used to make several types of measurements in a radiation field and there is a unique voltage applied to each detector type. Some electronic devices that are built of semiconductor materials like silicon crystal can also be used for the same purpose. In this case, a characteristic curve of the device must be acquired to choose an operation point which consists of an electrical current or voltage to be applied to the device. Unlike ion chambers, such an electronic device can have different operation points depending on its current versus voltage curve (I x V). The best operation point of the device is also a function of the radiation, energy, dose rate and fluence. The purpose of this work is to show a semiconductor parameter analyzer built to acquire I x V curves as usually, and the innovation here is the fact that it can be used to obtain such a parametric curve when a quad-polar device is under irradiation. The results demonstrate that the system is a very important tool to scientists interested to evaluate a semiconductor detector before, during and after irradiation. A collection of results for devices under an X-ray beam and a neutron fluence are presented: photodiode, phototransistors, bipolar transistor and MOSFET. (author)

  11. Reporting detection efficiency for semiconductor neutron detectors: A need for a standard

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S., E-mail: mcgregor@ksu.ed [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506 (United States); Kenneth Shultis, J. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506 (United States)

    2011-03-11

    In the past few years, there has been an increased interest in the development of alternative neutron detection technologies. Included among many promising alternative neutron detection technologies are semiconductor-based neutron detectors. These detectors are typically small and compact, hence those methods used to characterize large gas-filled neutron detectors are inappropriate. Proposed are standard methods that can be used to model the performance of semiconductor neutron detectors and to characterize experimentally the intrinsic efficiency of these detectors.

  12. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs)

    Energy Technology Data Exchange (ETDEWEB)

    Fronk, Ryan G., E-mail: rfronk@ksu.edu [Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506, United States (United States); Bellinger, Steven L.; Henson, Luke C. [Radiation Detection Technologies, Inc., Manhattan, KS 66502 (United States); Ochs, Taylor R.; Smith, Colten T.; Kenneth Shultis, J.; McGregor, Douglas S. [Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506, United States (United States)

    2015-12-21

    Microstructured semiconductor neutron detectors (MSNDs) have in recent years received much interest as high-efficiency replacements for thin-film-coated thermal neutron detectors. The basic device structure of the MSND involves micro-sized trenches that are etched into a vertically-oriented pvn-junction diode that are backfilled with a neutron converting material. Neutrons absorbed within the converting material induce fission of the parent nucleus, producing a pair of energetic charged-particle reaction products that can be counted by the diode. The MSND deep-etched microstructures produce good neutron-absorption and reaction-product counting efficiencies, offering a 10× improvement in intrinsic thermal neutron detection efficiency over thin-film-coated devices. Performance of present-day MSNDs are nearing theoretical limits; streaming paths between the conversion-material backfilled trenches, allow a considerable fraction of neutrons to pass undetected through the device. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs) have been developed that utilize a complementary second set of trenches on the back-side of the device to count streaming neutrons. DSMSND devices are theoretically capable of greater than 80% intrinsic thermal neutron detection efficiency for a 1-mm thick device. The first such prototype DSMSNDs, presented here, have achieved 29.48±0.29% nearly 2× better than MSNDs with similar microstructure dimensions.

  13. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs)

    Science.gov (United States)

    Fronk, Ryan G.; Bellinger, Steven L.; Henson, Luke C.; Ochs, Taylor R.; Smith, Colten T.; Kenneth Shultis, J.; McGregor, Douglas S.

    2015-12-01

    Microstructured semiconductor neutron detectors (MSNDs) have in recent years received much interest as high-efficiency replacements for thin-film-coated thermal neutron detectors. The basic device structure of the MSND involves micro-sized trenches that are etched into a vertically-oriented pvn-junction diode that are backfilled with a neutron converting material. Neutrons absorbed within the converting material induce fission of the parent nucleus, producing a pair of energetic charged-particle reaction products that can be counted by the diode. The MSND deep-etched microstructures produce good neutron-absorption and reaction-product counting efficiencies, offering a 10× improvement in intrinsic thermal neutron detection efficiency over thin-film-coated devices. Performance of present-day MSNDs are nearing theoretical limits; streaming paths between the conversion-material backfilled trenches, allow a considerable fraction of neutrons to pass undetected through the device. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs) have been developed that utilize a complementary second set of trenches on the back-side of the device to count streaming neutrons. DSMSND devices are theoretically capable of greater than 80% intrinsic thermal neutron detection efficiency for a 1-mm thick device. The first such prototype DSMSNDs, presented here, have achieved 29.48±0.29% nearly 2× better than MSNDs with similar microstructure dimensions.

  14. Organic semiconductor nickel phthalocyanine-based photocapacitive and photoresistive detector

    Science.gov (United States)

    Shah, Mutabar; Karimov, Kh S.; Sayyad, M. H.

    2010-07-01

    In this study, the photosensitive organic semiconductor nickel phthalocyanine (NiPc) is investigated as a photocapacitive and photoresistive detector. NiPc thin film is grown by vacuum thermal evaporation on an indium tin oxide (ITO)-coated glass substrate. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is deposited as a top electrode by drop-casting to fabricate the ITO/NiPc/PEDOT:PSS light detector. It has been observed that under the unmodulated filament lamp illumination of up to 9720 lux the capacitance of the detectors increased up to 21, 18 and 4% at a frequency of measuring voltage of 120 Hz, 1 kHz and 10 kHz, respectively, under dark conditions. The change in resistance with the variation in the intensity of light is also investigated. The capacitance and resistance of the light detector decrease with an increase in the frequency. It is assumed that the photocapacitive and photoresistive response of the detector is associated with polarization occurring due to the transfer of photo-generated electrons and holes. The calculated results are in reasonable agreement with the experimental results.

  15. Semiconductor micropattern pixel detectors a review of the beginnings

    CERN Document Server

    Heijne, Erik H M

    2001-01-01

    The innovation in monolithic and hybrid semiconductor 'micropattern' or 'reactive' pixel detectors for tracking in particle physics was actually to fit logic and pulse processing electronics with µW power on a pixel area of less than 0.04 mm2, retaining the characteristics of a traditional nuclear amplifier chain. The ns timing precision in conjunction with local memory and logic operations allowed event selection at > 10 MHz rates with unambiguous track reconstruction even at particle multiplicities > 10 cm-2. The noise in a channel was ~100 e- r.m.s. and enabled binary operation with random noise 'hits' at a level 30 Mrad, respectively.

  16. Cryogenic Semiconductor Detectors: Simulation of Signal Formation & Irradiation Beam Test

    CERN Document Server

    AUTHOR|(CDS)2091318; Stamoulis, G; Vavougios, D

    The Beam Loss Monitoring system of the Large Hadron Collider is responsible for the pro- tection of the machine from damage and for the prevention of a magnet quench. Near the interaction points of the LHC, in the triplet magnets area, the BLMs are sensitive to the collision debris, limiting their ability to distinguish beam loss signal from signal caused due to the collision products. Placing silicon & diamond detectors inside the cold mass of the mag- nets, in liquid helium temperatures, would provide significant improvement to the precision of the measurement of the energy deposition in the superconducting coil of the magnet. To further study the signal formation and the shape of the transient current pulses of the aforementioned detectors in cryogenic temperatures, a simulation application has been developed. The application provides a fast way of determining the electric field components inside the detectors bulk and then introduces an initial charge distribution based on the properties of the radiat...

  17. Far Infrared Optical Properties of Bulk Wurtzite Zinc Oxide Semiconductor

    Institute of Scientific and Technical Information of China (English)

    Pohkok Ooi; Saicheong Lee; Shashiong Ng; Zainuriah Hassan; Haslan Abu Hassan

    2011-01-01

    Polarized far infrared (FIR) reflectance technique was applied to study the optical properties of a bulk wurtzite zinc oxide (ZnO) single crystal. Room temperature polarized FIR reflectance spectra were taken at various angles of incidence, from 20° to 70°. The theoretical polarized FIR reflectance spectra were simulated based on the anisotropic dielectric function model. Good agreement was achieved between the experimental and the theoretical FIR reflectance spectra. Through this work, a complete set of reststrahlen parameters of a bulk wurtzite ZnO at the Brillouin zone centre was obtained. Additionally, other FIR optical properties such as the real and the imaginary parts of the complex dielectric function, real and imaginary parts of the refractive index, the absorption coefficient and the reciprocal of the absorption coefficient were also obtained by using numerical calculation.

  18. Experimental study of the response of semiconductor detectors to low-energy photons

    CERN Document Server

    Lepy, M C; Laborie, J M; Plagnard, J; Stemmler, P; Teesdale, W J

    2000-01-01

    Six semiconductor detectors (Si(Li) and HPGe) are calibrated in the 1-10 keV energy range by means of tuneable monochromatised synchrotron radiation. Significant improvement in the quality of the response is observed in very recent detectors. A peak shape calibration is established using a modified Hypermet-type function to model the detector response for each energy step; electron effects induce individual background and tail shapes for each detector material. Fano factors for both semiconductor materials are experimentally derived. The efficiency calibration is determined using a proportional counter as reference: the front semiconductor layer acts as a partially active zone.

  19. Performance of bulk SiC radiation detectors

    CERN Document Server

    Cunningham, W; Lamb, G; Scott, J; Mathieson, K; Roy, P; Bates, R; Thornton, P; Smith, K M; Cusco, R; Glaser, M; Rahman, M

    2002-01-01

    SiC is a wide-gap material with excellent electrical and physical properties that may make it an important material for some future electronic devices. The most important possible applications of SiC are in hostile environments, such as in car/jet engines, within nuclear reactors, or in outer space. Another area where the material properties, most notably radiation hardness, would be valuable is in the inner tracking detectors of particle physics experiments. Here, we describe the performance of SiC diodes irradiated in the 24 GeV proton beam at CERN. Schottky measurements have been used to probe the irradiated material for changes in I-V characteristics. Other methods, borrowed from III-V research, used to study the irradiated surface include atomic force microscope scans and Raman spectroscopy. These have been used to observe the damage to the materials surface and internal lattice structure. We have also characterised the detection capabilities of bulk semi-insulating SiC for alpha radiation. By measuring ...

  20. Semiconductor Detector Developments for High Energy Space Astronomy

    CERN Document Server

    Meuris, Aline

    2014-01-01

    The rise of high energy astrophysics and solar physics in the 20th century is linked to the development of space telescopes; since the 1960s they have given access to the X-ray and gamma-ray sky, revealing the most violent phenomena in the Universe. Research and developments in imaging concepts and sensing materials haven't stopped since yet to improve the sensitivity of the X-ray and gamma-ray observatories. The paper proposes an overview of instrument realizations and focuses on the innovative detection techniques and technologies for applications from 0.1 keV to 10 MeV energy range. Solid-state detectors are prominent solutions for space instrumentation because of their excellent imaging and spectroscopic capabilities with limited volume and power resources. Various detection concepts based on semiconductors (Compton camera, Cd(Zn)Te pixel hybrids, DePFET active pixel sensors) are under design or fabrication for the near-future missions like Astro-H, BepiColombo, Solar Orbiter. New technologies on sensing ...

  1. High frame rate measurements of semiconductor pixel detector readout IC

    Science.gov (United States)

    Szczygiel, R.; Grybos, P.; Maj, P.

    2012-07-01

    We report on high count rate and high frame rate measurements of a prototype IC named FPDR90, designed for readouts of hybrid pixel semiconductor detectors used for X-ray imaging applications. The FPDR90 is constructed in 90 nm CMOS technology and has dimensions of 4 mm×4 mm. Its main part is a matrix of 40×32 pixels with 100 μm×100 μm pixel size. The chip works in the single photon counting mode with two discriminators and two 16-bit ripple counters per pixel. The count rate per pixel depends on the effective CSA feedback resistance and can be set up to 6 Mcps. The FPDR90 can operate in the continuous readout mode, with zero dead time. Due to the architecture of digital blocks in pixel, one can select the number of bits read out from each counter from 1 to 16. Because in the FPDR90 prototype only one data output is available, the frame rate is 9 kfps and 72 kfps for 16 bits and 1 bit readout, respectively (with nominal clock frequency of 200 MHz).

  2. High frame rate measurements of semiconductor pixel detector readout IC

    Energy Technology Data Exchange (ETDEWEB)

    Szczygiel, R., E-mail: robert.szczygiel@agh.edu.pl [AGH University of Science and Technology, Department of Measurement and Instrumentation, Al. Mickiewicza 30, 30-059 Cracow (Poland); Grybos, P.; Maj, P. [AGH University of Science and Technology, Department of Measurement and Instrumentation, Al. Mickiewicza 30, 30-059 Cracow (Poland)

    2012-07-11

    We report on high count rate and high frame rate measurements of a prototype IC named FPDR90, designed for readouts of hybrid pixel semiconductor detectors used for X-ray imaging applications. The FPDR90 is constructed in 90 nm CMOS technology and has dimensions of 4 mm Multiplication-Sign 4 mm. Its main part is a matrix of 40 Multiplication-Sign 32 pixels with 100 {mu}m Multiplication-Sign 100 {mu}m pixel size. The chip works in the single photon counting mode with two discriminators and two 16-bit ripple counters per pixel. The count rate per pixel depends on the effective CSA feedback resistance and can be set up to 6 Mcps. The FPDR90 can operate in the continuous readout mode, with zero dead time. Due to the architecture of digital blocks in pixel, one can select the number of bits read out from each counter from 1 to 16. Because in the FPDR90 prototype only one data output is available, the frame rate is 9 kfps and 72 kfps for 16 bits and 1 bit readout, respectively (with nominal clock frequency of 200 MHz).

  3. Simulation of one-dimensionally polarized X-ray semiconductor detectors

    NARCIS (Netherlands)

    Engel, K.J.; Herrmann, C.

    2011-01-01

    Abstract: A pixelated X-ray semiconductor detector (=“direct converter”) is studied which contains an inhomogeneous electric field parallel to the depth axis caused by different concentrations of p- or n-doping. The X-ray energy deposition and charge movement within the detector is modeled in Monte-

  4. Bulk and surface properties of ZnTe-ZnS system semiconductors

    Science.gov (United States)

    Kirovskaya, I. A.; Mironova, E. V.; Kosarev, B. A.; Nor, P. E.; Bukashkina, T. L.

    2016-10-01

    Physicochemical studies of a new ZnTe-ZnS semiconductor system are conducted. It is found that at certain ratios of binary components, substitutional solid solutions with a cubic sphalerite structure are formed in this system. Interrelated laws governing changes in the bulk (crystal chemical, structural) and surface (acid-base) properties with varying system composition are identified. It is assumed they can be attributed to the nature of the active (acid-base) sites. The presented data, observed patterns, and an interpretation of them are used not only to confirm earlier proposed mechanisms of atomic-molecular interaction on diamond-like semiconductors, but to search for promising materials for use in highly sensitive selective sensors for environmental and medical purposes as well.

  5. Semiconductor scintillator detector for gamma radiation; Detector cintilador semicondutor para radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S., E-mail: ftvdl@ufrgs.br, E-mail: borges@ufrgs.br, E-mail: jorge.zabadal@ufrgs.br [Universidade Federal do Rio Grande do Sul (GENUC/DEMEC/UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares. Departamento de Engenharia Mecanica

    2015-07-01

    Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

  6. Instrumentation for characterizing materials and composed semiconductors for ionizing radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Paschoal, Arquimedes J.A.; Leite, Adolfo M.B.; Nazzre, Fabio V.B.; Santos, Luiz A.P. [Centro Regional de Ciencias Nucleares (CRCN/CNEN-PE), Recife, PE (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: lasantos@cnen.gov.br

    2007-07-01

    The purpose of this work is the development of instrumentation for characterizing some type of ionizing radiation detectors. Those detectors are being manufactured by the Nuclear Instrumentation Laboratory at CRCN/Recife and can be used both on photon beam and with particles. Such detectors consist of semiconductor material in the form of films generated by oxide growing or by means of semiconductor material deposition in a substrate. Those materials can be made of metals, semi-metals, composites or semiconductor polymers. Prior to expose those detectors to ionizing radiation, it must be physically and electrically characterized. In this intention it was developed an electromechanical system. An electrical circuit was built to measure the signal from the detector and another circuit to control the movement of four probes (4-points technique) by using a stepper motor and the micro stepping technique avoiding damage to the detector. This system can be of interest to researchers that work with a sort of semiconductor materials in the form of thin film and in nanotechnological processes aiming the design of radiation ionizing detectors. (author)

  7. Exploring graphene field effect transistor devices to improve spectral resolution of semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Richard Karl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen Wayne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Jeffrey B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hamilton, Allister B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-12-01

    Graphene, a planar, atomically thin form of carbon, has unique electrical and material properties that could enable new high performance semiconductor devices. Graphene could be of specific interest in the development of room-temperature, high-resolution semiconductor radiation spectrometers. Incorporating graphene into a field-effect transistor architecture could provide an extremely high sensitivity readout mechanism for sensing charge carriers in a semiconductor detector, thus enabling the fabrication of a sensitive radiation sensor. In addition, the field effect transistor architecture allows us to sense only a single charge carrier type, such as electrons. This is an advantage for room-temperature semiconductor radiation detectors, which often suffer from significant hole trapping. Here we report on initial efforts towards device fabrication and proof-of-concept testing. This work investigates the use of graphene transferred onto silicon and silicon carbide, and the response of these fabricated graphene field effect transistor devices to stimuli such as light and alpha radiation.

  8. High-sensitivity visible-blind UV detectors made with organic semiconductors

    Science.gov (United States)

    Yu, Gang; Cao, Yong; Srdanov, Gordana

    1999-04-01

    High sensitivity visible-blind UV detectors were fabricated with organic semiconductors. The photo-sensitivity at 350 nm reaches 75 mA/Watt, corresponding to quantum efficiency of approximately 27% el/ph. The visible/UV suppression ratio is more than 10(superscript 4) without optical filters. These UV detectors are of linear intensity dependence with fast response time. The simple fabrication process allows these UV detectors to be made in large size, in flexible forms or onto non-planar substrates with low cost. The fabrication process also allows these UV detectors to be integrated with electronic devices or optical devices.

  9. High-efficiency microstructured semiconductor neutron detectors that are arrayed, dual-integrated, and stacked

    Energy Technology Data Exchange (ETDEWEB)

    Bellinger, Steven L., E-mail: slb3888@ksu.edu [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Fronk, Ryan G. [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Sobering, Timothy J. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2012-07-15

    Silicon diodes with large aspect ratio 3D microstructures backfilled with {sup 6}LiF show a significant increase in neutron detection efficiency beyond that of conventional thin-film coated planar devices. Described in this work are advancements in the technology using detector stacking methods and summed-detector 6 Multiplication-Sign 6-element arraying methods to dramatically increase the sensitivity to thermal neutrons. The intrinsic detection efficiency of the 6 Multiplication-Sign 6 array for normal-incident 0.0253 eV neutrons was found 6.8% compared against a calibrated {sup 3}He proportional counter. - Highlights: Black-Right-Pointing-Pointer Solid-state semiconductor neutron detectors utilizing {sup 6}LiF. Black-Right-Pointing-Pointer Large aspect ratio 3D microstructured silicon diodes. Black-Right-Pointing-Pointer Arrayed solid-state semiconductor neutron detectors.

  10. Direct determination of bulk etching rate for LR-115-II solid state nuclear track detectors

    Indian Academy of Sciences (India)

    T A Salama; U Seddik; T M Heggazy; A Ahmed Morsy

    2006-09-01

    The thickness of the removed layer of the LR-115-II solid state nuclear track detector during etching is measured directly with a rather precise instrument. Dependence of bulk etching rate on temperature of the etching solution is investigated. It has been found that the bulk etching rate is 3.2 m/h at 60°C in 2.5 N NaOH of water solution. It is also found that the track density in detectors exposed to soil samples increases linearly with the removed layer.

  11. Epitaxial silicon semiconductor detectors, past developments, future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, C.R.

    1976-01-01

    A review of the main physical characteristics of epitaxial silicon as it relates to detector development is presented. As examples of applications results are presented on (1) epitaxial silicon avalanche diodes (ESAD); signal-to-noise, non-linear aspects of the avalanche gain mechanism, gain-bandwidth product, (2) ultrathin epitaxial silicon surface barrier (ESSB) detectors, response to heavy ions, (3) an all-epitaxial silicon diode (ESD), response to heavy ions, charge transport and charge defect. Future prospects of epitaxial silicon as it relates to new detector designs are summarized.

  12. Epitaxial silicon semiconductor detectors: past developments, future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, C.R.

    1977-02-01

    A review of the main physical characteristics of epitaxial silicon as it relates to detector development is presented. As examples of applications results are presented on (1) epitaxial silicon avalanche diodes (ESAD); signal-to-noise, non-linear aspects of the avalanche gain mechanism, gain-bandwidth product, (2) ultrathin epitaxial silicon surface barrier (ESSB) detectors, response to heavy ions, (3) an all-epitaxial silicon diode (ESD), response to heavy ions, charge transport and charge defect. Future prospects of epitaxial silicon as it relates to new detector designs are summarized.

  13. An evaluation of semiconductor and ionization chamber detectors for diagnostic x-ray dosimetry measurements.

    Science.gov (United States)

    Martin, C J

    2007-08-07

    Dosemeters for performance testing of x-ray equipment may utilize semiconductor technology or ionization chambers (ICs). Semiconductor dosemeters incorporate several elements into the detectors from which compensation for variations in response with photon energy is derived. The design of the detectors influences their response with angle and this is different from that of ICs. The responses of semiconductor detectors (SDs) and ICs to x-ray beams with a variety of radiation qualities have been measured in order to assess differences in response. Measurements have been made with experimental arrangements simulating use of the detectors in performance testing of digital radiography and fluoroscopy equipment. Results show that differences in photon energy responses between the detectors are small, but because ICs are sensitive to radiation incident from all angles, they record more scattered radiation than SDs. Implications of differences in detector responses are discussed and recommendations made about their use. SDs are more appropriate for measurements of image receptor doses and are recommended for setting up automatic exposure control devices for digital radiography. ICs are suitable for assessment of patient entrance surface dose rate measurements. Correction factors that could be applied to allow comparisons between measurements with different dosemeters are proposed.

  14. Growth of Bulk Wide Bandgap Semiconductor Crystals and Their Potential Applications

    Science.gov (United States)

    Chen, Kuo-Tong; Shi, Detang; Morgan, S. H.; Collins, W. Eugene; Burger, Arnold

    1997-01-01

    Developments in bulk crystal growth research for electro-optical devices in the Center for Photonic Materials and Devices since its establishment have been reviewed. Purification processes and single crystal growth systems employing physical vapor transport and Bridgman methods were assembled and used to produce high purity and superior quality wide bandgap materials such as heavy metal halides and II-VI compound semiconductors. Comprehensive material characterization techniques have been employed to reveal the optical, electrical and thermodynamic properties of crystals, and the results were used to establish improved material processing procedures. Postgrowth treatments such as passivation, oxidation, chemical etching and metal contacting during the X-ray and gamma-ray device fabrication process have also been investigated and low noise threshold with improved energy resolution has been achieved.

  15. Dynamical effects and terahertz harmonic generation in low-doped bulk semiconductors and submicron structures

    Energy Technology Data Exchange (ETDEWEB)

    Persano Adorno, D.; Capizzo, M.C.; Zarcone, M. [Dipartimento di Fisica e Tecnologie Relative, Viale delle Scienze, Ed. 18, 90128, Palermo (Italy)

    2006-08-15

    We present results obtained using a three-dimensional multivalleys Monte Carlo (MC) model to simulate the nonlinear carrier dynamics under the influence of an intense sub-terahertz electric field in a doped bulk semiconductor. By self-consistently coupling a one-dimensional Poisson solver to the ensemble MC code we simulate also the nonlinear carrier dynamics in n{sup +}nn{sup +} structures operating under large-amplitude periodic signals and investigate the voltage-current characteristic hysteresis cycle and the high-order harmonic efficiency. For both cases we discuss the dependence of the nonlinearities and of the harmonic generation efficiency on the frequency and the intensity of the alternating signal. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Non-streaming high-efficiency perforated semiconductor neutron detectors, methods of making same and measuring wand and detector modules utilizing same

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S. (Riley, KS); Shultis, John K. (Manhattan, KS); Rice, Blake B. (Manhattan, KS); McNeil, Walter J. (Winnfield, KS); Solomon, Clell J. (Wichita, KS); Patterson, Eric L. (Manhattan, KS); Bellinger, Steven L. (Manhattan, KS)

    2010-12-21

    Non-streaming high-efficiency perforated semiconductor neutron detectors, method of making same and measuring wands and detector modules utilizing same are disclosed. The detectors have improved mechanical structure, flattened angular detector responses, and reduced leakage current. A plurality of such detectors can be assembled into imaging arrays, and can be used for neutron radiography, remote neutron sensing, cold neutron imaging, SNM monitoring, and various other applications.

  17. Alpha-ray spectrometry at high temperature by using a compound semiconductor detector.

    Science.gov (United States)

    Ha, Jang Ho; Kim, Han Soo

    2013-11-01

    The use of conventional radiation detectors in harsh environments is limited by radiation damage to detector materials and by temperature constraints. We fabricated a wide-band gap semiconductor radiation detector based on silicon carbide. All the detector components were considered for an application in a high temperature environment like a nuclear reactor core. The radiation response, especially to alpha particles, was measured using an (241)Am source at variable operating voltages at room temperature in the air. The temperature on detector was controlled from 30°C to 250°C. The alpha-particle spectra were measured at zero bias operation. Even though the detector is operated at high temperature, the energy resolution as a function of temperature is almost constant within 3.5% deviation.

  18. Phonon-electron interactions in piezoelectric semiconductor bulk acoustic wave resonators.

    Science.gov (United States)

    Gokhale, Vikrant J; Rais-Zadeh, Mina

    2014-07-08

    This work presents the first comprehensive investigation of phonon-electron interactions in bulk acoustic standing wave (BAW) resonators made from piezoelectric semiconductor (PS) materials. We show that these interactions constitute a significant energy loss mechanism and can set practical loss limits lower than anharmonic phonon scattering limits or thermoelastic damping limits. Secondly, we theoretically and experimentally demonstrate that phonon-electron interactions, under appropriate conditions, can result in a significant acoustic gain manifested as an improved quality factor (Q). Measurements on GaN resonators are consistent with the presented interaction model and demonstrate up to 35% dynamic improvement in Q. The strong dependencies of electron-mediated acoustic loss/gain on resonance frequency and material properties are investigated. Piezoelectric semiconductors are an extremely important class of electromechanical materials, and this work provides crucial insights for material choice, material properties, and device design to achieve low-loss PS-BAW resonators along with the unprecedented ability to dynamically tune resonator Q.

  19. Experimental characterization of semiconductor-based thermal neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bedogni, R., E-mail: roberto.bedogni@lnf.infn.it [IFNF—LNF, via E. Fermi n. 40, 00044 Frascati, Roma (Italy); Bortot, D.; Pola, A.; Introini, M.V.; Lorenzoli, M. [Politecnico di Milano, Dipartimento di Energia, via La Masa 34, 20156 Milano (Italy); INFN—Milano, Via Celoria 16, 20133 Milano (Italy); Gómez-Ros, J.M. [IFNF—LNF, via E. Fermi n. 40, 00044 Frascati, Roma (Italy); CIEMAT, Av. Complutense 40, 28040 Madrid (Spain); Sacco, D. [IFNF—LNF, via E. Fermi n. 40, 00044 Frascati, Roma (Italy); INAIL—DIT, Via di Fontana Candida 1, 00040 Monteporzio Catone (Italy); Esposito, A.; Gentile, A.; Buonomo, B. [IFNF—LNF, via E. Fermi n. 40, 00044 Frascati, Roma (Italy); Palomba, M.; Grossi, A. [ENEA Triga RC-1C.R. Casaccia, via Anguillarese 301, 00060 S. Maria di Galeria, Roma (Italy)

    2015-04-21

    In the framework of NESCOFI@BTF and NEURAPID projects, active thermal neutron detectors were manufactured by depositing appropriate thickness of {sup 6}LiF on commercially available windowless p–i–n diodes. Detectors with different radiator thickness, ranging from 5 to 62 μm, were manufactured by evaporation-based deposition technique and exposed to known values of thermal neutron fluence in two thermal neutron facilities exhibiting different irradiation geometries. The following properties of the detector response were investigated and presented in this work: thickness dependence, impact of parasitic effects (photons and epithermal neutrons), linearity, isotropy, and radiation damage following exposure to large fluence (in the order of 10{sup 12} cm{sup −2})

  20. Organic semiconductors as real-time radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, T., E-mail: tsuzuki@hep.sc.niigata-u.ac.jp [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Miyata, H., E-mail: miyata@hep.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Katsumata, M. [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Nakano, S.; Matsuda, K. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Tamura, M. [Carlit Holdings Co., Ltd., Tokyo 104-0031 (Japan)

    2014-11-01

    In this study, the possibility of using π-conjugated organic semiconducting polymers as real-time radiation detectors was explored. Polyaniline (PAni) was used to fabricate radiation sensors because of its relative long-term stability in air. Each fabricated sensor was then subjected to irradiation by α- and β-particles, and the real-time response was measured. The multichannel analyzer (MCA) data of the response signal for each irradiation was acquired and the detection efficiency, relative to the electrode bias voltage of the detector, was extracted.

  1. Materials processing threshold report. 1: Semiconductor crystals for infrared detectors

    Science.gov (United States)

    Sager, E. V.; Thompson, T. R.; Nagler, R. G.

    1980-01-01

    An extensive search was performed of the open literature pertaining to infrared detectors to determine what constitutes a good detector and in what way performance is limited by specific material properties. Interviews were conducted with a number of experts in the field to assess their perceptions of the state of the art and of the utility of zero-gravity processing. Based on this information base and on a review of NASA programs in crystal growth and infrared sensors, NASA program goals were reassessed and suggestions are presented as to possible joint and divergent efforts between NASA and DOD.

  2. X-ray imaging with photon counting hybrid semiconductor pixel detectors

    CERN Document Server

    Manolopoulos, S; Campbell, M; Snoeys, W; Heijne, Erik H M; Pernigotti, E; Raine, C; Smith, K; Watt, J; O'Shea, V; Ludwig, J; Schwarz, C

    1999-01-01

    Semiconductor pixel detectors, originally developed for particle physics experiments, have been studied as X-ray imaging devices. The performance of devices using the OMEGA 3 read-out chip bump-bonded to pixellated silicon semiconductor detectors is characterised in terms of their signal-to-noise ratio when exposed to 60 kVp X-rays. Although parts of the devices achieve values of this ratio compatible with the noise being photon statistics limited, this is not found to hold for the whole pixel matrix, resulting in the global signal-to-noise ratio being compromised. First results are presented of X-ray images taken with a gallium arsenide pixel detector bump-bonded to a new read-out chip, (MEDIPIX), which is a single photon counting read-out chip incorporating a 15-bit counter in every pixel. (author)

  3. X-ray imaging with photon counting hybrid semiconductor pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Manolopoulos, S.; Bates, R.; Campbell, M.; Snoeys, W.; Heijne, E.; Pernigotti, E.; Raine, C.; Smith, K. E-mail: k.smith@physics.gla.ac.uk; Watt, J.; O' Shea, V.; Ludwig, J.; Schwarz, C

    1999-09-11

    Semiconductor pixel detectors, originally developed for particle physics experiments, have been studied as X-ray imaging devices. The performance of devices using the {omega}3 read-out chip bump-bonded to pixellated silicon semiconductor detectors is characterised in terms of their signal-to-noise ratio when exposed to 60 kVp X-rays. Although parts of the devices achieve values of this ratio compatible with the noise being photon statistics limited, this is not found to hold for the whole pixel matrix, resulting in the global signal-to-noise ratio being compromised. First results are presented of X-ray images taken with a gallium arsenide pixel detector bump-bonded to a new read-out chip, (MEDIPIX), which is a single photon counting read-out chip incorporating a 15-bit counter in every pixel. (author)

  4. Giant magneto-optical response in non-magnetic semiconductor BiTeI driven by bulk Rashba spin splitting

    OpenAIRE

    Demkó, L.; Schober, G. A. H.; Kocsis, V.; Bahramy, M.S.; Murakawa, H.; Lee, J. S.; Kézsmárki, I.; Arita, R.; Nagaosa, N.; Tokura, Y.

    2012-01-01

    We study the magneto-optical (MO) response of polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being non-magnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (

  5. Quantum coherence in semiconductor nanostructures for improved lasers and detectors.

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Weng Wah Dr. (; .); Lyo, Sungkwun Kenneth; Cederberg, Jeffrey George; Modine, Normand Arthur; Biefeld, Robert Malcolm

    2006-02-01

    The potential for implementing quantum coherence in semiconductor self-assembled quantum dots has been investigated theoretically and experimentally. Theoretical modeling suggests that coherent dynamics should be possible in self-assembled quantum dots. Our experimental efforts have optimized InGaAs and InAs self-assembled quantum dots on GaAs for demonstrating coherent phenomena. Optical investigations have indicated the appropriate geometries for observing quantum coherence and the type of experiments for observing quantum coherence have been outlined. The optical investigation targeted electromagnetically induced transparency (EIT) in order to demonstrate an all optical delay line.

  6. Influence of backscattering on the spatial resolution of semiconductor X-ray detectors

    Science.gov (United States)

    Hoheisel, M.; Korn, A.; Giersch, J.

    2005-07-01

    Pixelated X-ray detectors using semiconductor layers or scintillators as absorbers are widely used in high-energy physics, medical diagnosis, or non-destructive testing. Their good spatial resolution performance makes them particularly suitable for applications where fine details have to be resolved. Intrinsic limitations of the spatial resolution have been studied in previous simulations. These simulations focused on interactions inside the conversion layer. Transmitted photons were treated as a loss. In this work, we also implemented the structure behind the conversion layer to investigate the impact of backscattering inside the detector setup. We performed Monte Carlo simulations with the program ROSI ( Roentgen Simulation) which is based on the well-established EGS4 algorithm. Line-spread functions of different fully implemented detectors were simulated. In order to characterize the detectors' spatial resolution, the modulation transfer functions (MTF) were calculated. The additional broadening of the line-spread function by carrier transport has been ignored in this work. We investigated two different detector types: a directly absorbing pixel detector where a semiconductor slab is bump-bonded to a readout ASIC such as the Medipix-2 setup with Si or GaAs as an absorbing semiconductor layer, and flat-panel detectors with a Se or a CsI converter. We found a significant degradation of the MTF compared to the case without backscattering. At energies above the K-edge of the backscattering material the spatial resolution drops and can account for the observed low-frequency drop of the MTF. Ignoring this backscatter effect might lead to misinterpretations of the charge sharing effect in counting pixel detectors.

  7. Fine-pitch semiconductor detector for the FOXSI mission

    CERN Document Server

    Ishikawa, Shin-nosuke; Tajima, Hiroyasu; Tanaka, Takaaki; Watanabe, Shin; Odaka, Hirokazu; Fukuyama, Taro; Kokubun, Motohide; Takahashi, Tadayuki; Terada, Yukikatsu; Krucker, Sam; Christe, Steven; McBride, Steve; Glesener, Lindsay

    2015-01-01

    The Focusing Optics X-ray Solar Imager (FOXSI) is a NASA sounding rocket mission which will study particle acceleration and coronal heating on the Sun through high sensitivity observations in the hard X-ray energy band (5-15 keV). Combining high-resolution focusing X-ray optics and fine-pitch imaging sensors, FOXSI will achieve superior sensitivity; two orders of magnitude better than that of the RHESSI satellite. As the focal plane detector, a Double-sided Si Strip Detector (DSSD) with a front-end ASIC (Application Specific Integrated Circuit) will fulfill the scientific requirements of spatial and energy resolution, low energy threshold and time resolution. We have designed and fabricated a DSSD with a thickness of 500 {\\mu}m and a dimension of 9.6 mm x 9.6 mm, containing 128 strips with a pitch of 75 {\\mu}m, which corresponds to 8 arcsec at the focal length of 2 m. We also developed a low-noise ASIC specified to FOXSI. The detector was successfully operated in the laboratory at a temperature of -20 C and w...

  8. X-ray measurement with Pin type semiconductor detectors; Medicion de rayos X con detectores de semiconductor tipo PIN

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, Departamento de Electronica, C.P. 52045 Salazar, Estado de Mexico (Mexico)

    2000-07-01

    Here are presented the experimental results of the applications of Pin type radiation detectors developed in a National Institute of Nuclear Research (ININ) project, in the measurement of low energy gamma and X-rays. The applications were oriented mainly toward the Medical Physics area. It is planned other applications which are in process of implementation inside the National Institute of Nuclear Research in Mexico. (Author)

  9. Effect of thermoelectromagnetic convection on the growth of bulk single crystals from semiconductor melts in a constant magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunov, L.A.

    1987-12-01

    The growth of bulk single crystals in semiconductor melts is investigated with emphasis on the effect of constant magnetic fields on the hydrodynamic processes and heat and mass transfer occurring in the melt. In particular, it is shown that the thermal emf in semiconductor melts can produce thermal currents whose interaction with a constant magnetic field can generate electromagnetic forces and lead to melt mixing (thermoelectromagnetic convection). The parameters of thermoelectromagnetic convection are estimated, and the importance of allowing for its effect in real processes is emphasized. 11 references.

  10. A full numerical calculation of the Franz-Keldysh effect on magnetoexcitons in a bulk semiconductor

    Institute of Scientific and Technical Information of China (English)

    Zhang Tong-Yi; Zhao Wei; Zhu Hai-Yan; Zhu Shao-Lan; Liu Xue-Ming

    2006-01-01

    We have performed a full numerical calculation of the Franz-Keldysh (FK) effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial value method in combination with the application of a perfect matched layer, the numerical effort and storage size are dramatically reduced due to a significant reduction in both computed domain and number of base functions. In the absence of an electric field, the higher magnetoexcitonic peaks show distinct Fano lineshape due to the degeneracy with continuum states of the lower Landau levels. The magnetoexcitons that belong to the zeroth Landau level remain in bound states and lead to Lorentzian lineshape, because they are not degenerated with continuum states. In the presence of an electric field, the FK effect on each magnetoexcitonic resonance can be identified for high magnetic fields. However, for low magnetic fields, the FK oscillations dominate the spectrum structure in the vicinity of the bandgap edge and the magnetoexcitonic resonances dominate the spectrum structure of higher energies. In the moderate electric fields, the interplay of FK effect and magnetoexcitonic resonance leads to a complex and rich structure in the absorption spectrum.

  11. Existence of the transverse relaxation time in optically excited bulk semiconductors

    Institute of Scientific and Technical Information of China (English)

    Zhang Hai-Chao; Lin Wei-Zhu; Wang Yu-Zhu

    2006-01-01

    Two basic types of depolarization mechanisms,carrier-carrier (CC) and carrier-phonon (CP) scattering,are investigated in optically excited bulk semiconductors (3D),in which the existence of the transverse relaxation time is proven based on the vector property of the interband transition matrix elements.The dephasing rates for both CC and CP scattering are determined to be equal to one half of the total scattering-rate-integrals weighted by the factors (1-COSx),wherex are the scattering angles.Analytical expressions of the polarization dephasing due to CC scattering are established by using an uncertainty broadening approach,and analytical ones due to both the polar optical-phonon and non-polar deformation potential scattering (including inter-valley scattering) are also presented by using the sharp spectral functions in the dephasing rate calculations.These formulas,which reveal the trivial role of the Coulomb screening effect in the depolarization processes,are used to explain the experimental results at hand and provide a clear physical picture that is difficult to extract from numerical treatments.

  12. The simulation of charge sharing in semiconductor X-ray pixel detectors

    CERN Document Server

    Mathieson, K; O'Shea, V; Passmore, M S; Rahman, M; Smith, K M; Watt, J; Whitehill, C

    2002-01-01

    Two simulation packages were used to model the sharing of charge, due to the scattering and diffusion of carriers, between adjacent pixel elements in semiconductors X-ray detectors. The X-ray interaction and the consequent multiple scattering was modelled with the aid of the Monte Carlo package, MCNP. The resultant deposited charge distribution was then used to create the charge cloud profile in the finite element semiconductor simulation code MEDICI. The analysis of the current pulses induced on pixel electrodes for varying photon energies was performed for a GaAs pixel detector. For a pixel pitch of 25 mu m, the charge lost to a neighbouring pixel was observed to be constant, at 0.6%, through the energies simulated. Ultimately, a fundamental limit on the pixel element size for imaging and spectroscopic devices may be set due to these key physical principles.

  13. Analysis of defect formation in semiconductor cryogenic bolometric detectors created by heavy dark matter

    CERN Document Server

    Lazanu, Ionel; Lazanu, Sorina

    2012-01-01

    The cryogenic detectors in the form of bolometers are presently used for different applications, in particular for very rare or hypothetical events associated with new forms of matter, specifically related to the existence of Dark Matter. In the detection of particles with a semiconductor as target and detector, usually two signals are measured: ionization and heat. The amplification of the thermal signal is obtained with the prescriptions from Luke-Neganov effect. The energy deposited in the semiconductor lattice as stable defects in the form of Frenkel pairs at cryogenic temperatures, following the interaction of a dark matter particle, is evaluated and consequences for measured quantities are discussed. This contribution is included in the energy balance of the Luke effect. Applying the present model to germanium and silicon, we found that for the same incident weakly interacting massive particle the energy deposited in defects in germanium is about twice the value for silicon.

  14. Investigation of efficient termination structure for improved breakdown properties of semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Krizaj, D.; Resnik, D.; Vrtacnik, D.; Amon, S. [Univ. of Ljubljana (Slovenia). Faculty of Electrical Engineering; Cindro, V. [Jozef Stefan Inst., Ljubljana (Slovenia)

    1998-06-01

    Efficiency of a new junction termination structure for improvement of breakdown properties of semiconductor radiation detectors is investigated. The structure consists of a diffused resistor winding around the active junction in a spiral fashion. The current flow through the spiral enables controlled potential distribution along the spiral turns and thus controlled depletion spreading from the main junction, efficiently preventing premature avalanche breakdown. Both multiple guard-ring structures and spiral junction termination structures have shown good breakdown properties typically three to five times higher than breakdown voltages of diodes without junction termination. The breakdown voltages of spiral junction termination structures are only weakly influenced by changes in substrate doping concentration caused by neutron irradiation. They can thus be considered for termination of future semiconductor radiation detectors.

  15. Development of radiation tolerant semiconductor detectors for the Super-LHC

    CERN Document Server

    Moll, M; Al-Ajili, A A; Alfieri, G; Allport, P P; Artuso, M; Assouak, S; Avset, B S; Barabash, L; Barcz, A; Bates, R; Biagi, S F; Bilei, G M; Bisello, D; Blue, A; Blumenau, A; Boisvert, V; Bölla, G; Bondarenko, G B; Borchi, E; Borrello, L; Bortoletto, D; Boscardin, M; Bosisio, L; Bowcock, T J V; Brodbeck, T J; Broz, J; Bruzzi, M; Brzozowski, A; Buda, M; Buhmann, P; Buttar, C; Campabadal, F; Campbell, D; Candelori, A; Casse, G; Cavallini, A; Charron, S; Chilingarov, A; Chren, D; Cindro, V; Collins, P; Coluccia, R; Contarato, D; Coutinho, J; Creanza, D; Cunningham, W; Betta, G F D; Dawson, I; de Boer, Wim; De Palma, M; Demina, R; Dervan, P; Dittongo, S; Dolezal, Z; Dolgolenko, A; Eberlein, T; Eremin, V; Fall, C; Fasolo, F; Fizzotti, F; Fleta, C; Focardi, E; Forton, E; Fretwurst, E; García, C; García-Navarro, J E; Gaubas, E; Genest, M H; Gill, K A; Giolo, K; Glaser, M; Gössling, C; Golovine, V; Sevilla, S G; Gorelov, I; Goss, J; Bates, A G; Grégoire, G; Gregori, P; Grigoriev, E; Grillo, A A; Groza, A; Guskov, J; Haddad, L; Härkönen, J; Hauler, F; Hoeferkamp, M; Honniger, F; Horazdovsky, T; Horisberger, Roland Paul; Horn, M; Houdayer, A; Hourahine, B; Hughes, G; Ilyashenko, Yu S; Irmscher, K; Ivanov, A; Jarasiunas, K; Johansen, K M H; Jones, B K; Jones, R; Joram, C; Jungermann, L; Kalinina, E; Kaminski, P; Karpenko, A; Karpov, A; Kazlauskiene, V; Kazukauskas, V; Khivrich, V; Khomenkov, V; Kierstead, J A; Klaiber Lodewigs, J; Klingenberg, R; Kodys, P; Kohout, Z; Korjenevski, S; Koski, M; Kozlowski, R; Kozodaev, M; Kramberger, G; Krasel, O; Kuznetsov, A; Kwan, S; Lagomarsino, S; Lassila-Perini, K M; Lastovetsky, V F; Latino, G; Lazanu, S; Lazanu, I; Lebedev, A; Lebel, C; Leinonen, K; Leroy, C; Li Z; Lindström, G; Linhart, V; Litovchenko, A P; Litovchenko, P G; Lo Giudice, A; Lozano, M; Luczynski, Z; Luukka, P; Macchiolo, A; Makarenko, L F; Mandic, I; Manfredotti, C; Manna, N; Garcia, S Mi; Marunko, S; Mathieson, K; Melone, J; Menichelli, D; Messineo, A; Metcalfe, J; Miglio, S; Mikuz, M; Miyamoto, J; Monakhov, E; Moscatelli, F; Naoumov, D; Nossarzhevska, E; Nysten, J; Olivero, P; OShea, V; Palviainen, T; Paolini, C; Parkes, C; Passeri, D; Pein, U; Pellegrini, G; Perera, L; Petasecca, M; Piemonte, C; Pignatel, G U; Pinho, N; Pintilie, I; Pintilie, L; Polivtsev, L; Polozov, P; Popa, A; Popule, J; Pospísil, S; Pozza, A; Radicci, V; Rafí, J M; Rando, R; Röder, R; Rohe, T; Ronchin, S; Rott, C; Roy, A; Ruzin, A; Sadrozinski, H F W; Sakalauskas, S; Scaringella, M; Schiavulli, L; Schnetzer, S; Schumm, B; Sciortino, S; Scorzoni, A; Segneri, G; Seidel, S; Seiden, A; Sellberg, G; Sellin, P J; Sentenac, D; Shipsey, I; Sícho, P; Sloan, T; Solar, M; Son, S; Sopko, B; Sopko, V; Spencer, N; Stahl, J; Stolze, D; Stone, R; Storasta, J; Strokan, N; Sudzius, M; Surma, B; Suvorov, A; Svensson, B G; Tipton, P; Tomasek, M; Tsvetkov, A; Tuominen, E; Tuovinen, E; Tuuva, T; Tylchin, M; Uebersee, H; Uher, J; Ullán, M; Vaitkus, J V; Velthuis, J; Verbitskaya, E; Vrba, V; Wagner, G; Wilhelm, I; Worm, S; Wright, V; Wunstorf, R; Yiuri, Y; Zabierowski, P; Zaluzhny, A; Zavrtanik, M; Zen, M; Zhukov, V; Zorzi, N

    2005-01-01

    The envisaged upgrade of the Large Hadron Collider (LHC) at CERN towards the Super-LHC (SLHC) with a 10 times increased luminosity of 10challenges for the tracking detectors of the SLHC experiments. Unprecedented high radiation levels and track densities and a reduced bunch crossing time in the order of 10ns as well as the need for cost effective detectors have called for an intensive R&D program. The CERN RD50 collaboration "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" is working on the development of semiconductor sensors matching the requirements of the SLHC. Sensors based on defect engineered silicon like Czochralski, epitaxial and oxygen enriched silicon have been developed. With 3D, Semi-3D and thin detectors new detector concepts have been evaluated and a study on the use of standard and oxygen enriched p-type silicon detectors revealed a promising approach for radiation tolerant cost effective devices. These and other most recent advancements of the RD50 ...

  16. Recent advancements in the development of radiation hard semiconductor detectors for S-LHC

    CERN Document Server

    Fretwurst, E; Al-Ajili, A A; Alfieri, G; Allport, P P; Artuso, M; Assouak, S; Avset, B S; Barabash, L; Barcz, A; Bates, R; Biagi, S F; Bilei, G M; Bisello, D; Blue, A; Blumenau, A; Boisvert, V; Bölla, G; Bondarenko, G B; Borchi, E; Borrello, L; Bortoletto, D; Boscardin, M; Bosisio, L; Bowcock, T J V; Brodbeck, T J; Broz, J; Bruzzi, M; Brzozowski, A; Buda, M; Buhmann, P; Buttar, C; Campabadal, F; Campbell, D; Candelori, A; Casse, G; Cavallini, A; Charron, S; Chilingarov, A G; Chren, D; Cindro, V; Collins, P; Coluccia, R; Contarato, D; Coutinho, J; Creanza, D; Cunningham, L; Dalla Betta, G F; Dawson, I; de Boer, Wim; De Palma, M; Demina, R; Dervan, P; Dittongo, S; Dolezal, Z; Dolgolenko, A; Eberlein, T; Eremin, V; Fall, C; Fasolo, F; Ferbel, T; Fizzotti, F; Fleta, C; Focardi, E; Forton, E; García, C; García-Navarro, J E; Gaubas, E; Genest, M H; Gill, K A; Giolo, K; Glaser, M; Gössling, C; Golovine, V; González-Sevilla, S; Gorelov,I; Goss, J; Gouldwell-Bates, A; Grégoire, G; Gregori, P; Grigoriev, E; Grillo, A A; Groza, A; Guskov, J; Haddad, L; Härkönen, J; Hauler, F; Hoeferkamp, M; Honniger, F; Horazdovsky, T; Horisberger, R P; Horn, M; Houdayer, A; Hourahine, B; Hughes, G; Ilyashenko, Yu S; Irmscher, K; Ivanov, A; Jarasiunas, K; Johansen, K M H; Jones, B K; Jones, R; Joram, C; Jungermann, L; Kalinina, E; Kaminski, P; Karpenko, A; Karpov, A; Kazlauskiene, V; Kazukauskas, V; Khivrich, V; Khomenkov, V P; Kierstead, J A; Klaiber Lodewigs, J M; Klingenberg, R; Kodys, P; Kohout, Z; Korjenevski, S; Koski, M; Kozlowski, R; Kozodaev, M; Kramberger, G; Krasel, O; Kuznetsov, A; Kwan, S; Lagomarsino, S; Lassila-Perini, K M; Lastovetsky, V F; Latino, G; Lazanu, I; Lazanu, S; Lebedev, A; Lebel, C; Leinonen, K; Leroy, C; Li, Z; Lindström, G; Linhart, V; Litovchenko, P G; Litovchenko, A P; Lo Giudice, A; Lozano, M; Luczynski, Z; Luukka, Panja; Macchiolo, A; Makarenko, L F; Mandic, I; Manfredotti, C; Manna, N; Martí i García, S; Marunko, S; Mathieson, K; Melone, J; Menichelli, D; Messineo, A; Metcalfe, J; Miglio, S; Mikuz, M; Miyamoto, J; Moll, M; Monakhov, E; Moscatelli, F; Naoumov, D; Nossarzhevska, E; Nysten, J; Olivero, P; O'Shea, V; Palviainen, T; Paolini, C; Parkes, C; Passeri, D; Pein, U; Pellegrini, G; Perera, L; Petasecca, M; Piemonte, C; Pignatel, G U; Pinho, N; Pintilie, I; Pintilie, L; Polivtsev, L; Polozov, P; Popa, A; Populea, J; Pospísil, S; Pozza, A; Radicci, V; Rafí, J M; Rando, R; Röder, R; Rohe, T; Ronchin, S; Rott, C; Roy, A; Ruzin, A; Sadrozinski, H F W; Sakalauskas, S; Scaringella, M; Schiavulli, L; Schnetzer, S; Schumm, B; Sciortino, S; Scorzoni, A; Segneri, G; Seidela, S; Seiden, A; Sellberg, G; Sellin, P J; Sentenac, D; Shipsey, I; Sícho, P; Sloan, T; Solar, M; Son, S; Sopko, B; Sopko, V; Spencer, N; Stahl, J; Stolze, D; Stone, R; Storasta, J; Strokan, N; Sudzius, M; Surma, B; Suvorov, A; Svensson, B G; Tipton, P; Tomasek, M; Tsvetkov, A; Tuominen, E; Tuovinen, E; Tuuva, T; Tylchin, M; Uebersee, H; Uher, J; Ullán, M; Vaitkus, J V; Velthuis, J; Verbitskaya, E; Vrba, V; Wagner, G; Wilhelm, I; Worm, S; Wright, V; Wunstorf, R; Yiuri, Y; Zabierowski, P; Zaluzhny, A; Zavrtanik, M; Zen, M; Zhukov, V; Zorzi, N

    2005-01-01

    The proposed luminosity upgrade of the Large Hadron Collider (S-LHC) at CERN will demand the innermost layers of the vertex detectors to sustain fluences of about 1016 hadrons/cm2. Due to the high multiplicity of tracks, the required spatial resolution and the extremely harsh radiation field new detector concepts and semiconductor materials have to be explored for a possible solution of this challenge. The CERN RD50 collaboration “Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders” has started in 2002 an R&D program for the development of detector technologies that will fulfill the requirements of the S-LHC. Different strategies are followed by RD50 to improve the radiation tolerance. These include the development of defect engineered silicon like Czochralski, epitaxial and oxygen-enriched silicon and of other semiconductor materials like SiC and GaN as well as extensive studies of the microscopic defects responsible for the degradation of irradiated sensors. Furthe...

  17. 2010 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room Temperature Semiconductor Detectors Workshop

    Science.gov (United States)

    The Nuclear Science Symposium (NSS) offers an outstanding opportunity for scientists and engineers interested or actively working in the fields of nuclear science, radiation instrumentation, software and their applications, to meet and discuss with colleagues from around the world. The program emphasizes the latest developments in technology and instrumentation and their implementation in experiments for space sciences, accelerators, other radiation environments, and homeland security. The Medical Imaging Conference (MIC) is the foremost international scientific meeting on the physics, engineering and mathematical aspects of nuclear medicine based imaging. As the field develops, multi-modality approaches are becoming more and more important. The content of the MIC reflects this, with a growing emphasis on the methodologies of X-ray, optical and MR imaging as they relate to nuclear imaging techniques. In addition, specialized topics will be addressed in the Short Courses and Workshops programs. The Workshop on Room-Temperature Semiconductor Detectors (RTSD) represents the largest forum of scientists and engineers developing new semiconductor radiation detectors and imaging arrays. Room-temperature solid-state radiation detectors for X-ray, gamma-ray, and neutron radiation are finding increasing applications in such diverse fields as medicine, homeland security, astrophysics and environmental remediation. The objective of this workshop is to provide a forum for discussion of the state of the art of material development for semiconductor, scintillator, and organic materials for detection, materials characterization, device fabrication and technology, electronics and applications.

  18. Alternative method to determine the bulk etch rate of Lr-115 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, D.; Sajo B, L.; Barros, H.; Greaves, E. D. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. Postal 89000, Caracas (Venezuela, Bolivarian Republic of); Palacios, F. [Universidad de Oriente, Santiago de Cuba (Cuba)

    2010-02-15

    The measurements using the Lr-115 solid-state nuclear track detector depend critically on the removed thickness of the active layer during etching. In this work, Lr-115 detectors exposed to alpha particles were etched under no stirring in a 2.5 N NaOH solution at a temperature of 60{+-}1 C and different etching times (from 0.5 to 2.5 hours). The thickness of the removed layer was determined by a variant of the gravimetric method, so that the bulk etch rate could be deduced from mass change measurements of detectors. The bulk etch rate was found to be 3.63 {+-} 0.09 {mu}m.h{sup -}1, which agrees with most of the reported values. Comparisons of our results with the obtained by the optical density method are in correspondence. We propose here a fast, simple, and nondestructive method to determine the active-layer thickness of the Lr-115 solid-state nuclear track detector with good accuracy for routine measurements. (Author)

  19. The study of response of wide band gap semiconductor detectors using the Geant4

    Directory of Open Access Journals (Sweden)

    Hussain Riaz

    2014-01-01

    Full Text Available The energy dependence on the intrinsic efficiency, absolute efficiency, full energy peak absolute efficiency and peak-to-total ratio have been studied for various wide band gap semiconductor detectors using the Geant4 based Monte Carlo simulations. The detector thickness of 1-4 mm and the area in 16-100 mm2 range were considered in this work. In excellent agreement with earlier work (Rybka et al., [20], the Geant4 simulated values of detector efficiencies have been found to decrease with incident g-ray energy. Both for the detector thickness and the detector area, the increasing trends have been observed for total efficiency as well as for full-energy peak efficiency in 0.1 MeV-50 MeV range. For Cd1-xZnxTe, the detector response remained insensitive to changes in relative proportions of Zn. For various wide band gap detectors studied in this work, the detection efficiency of TlBr was found highest over the entire range of energy, followed by the HgI2, CdTe, and then by CZT.

  20. Detection of fast neutrons from shielded nuclear materials using a semiconductor alpha detector.

    Science.gov (United States)

    Pöllänen, R; Siiskonen, T

    2014-08-01

    The response of a semiconductor alpha detector to fast (>1 MeV) neutrons was investigated by using measurements and simulations. A polyethylene converter was placed in front of the detector to register recoil protons generated by elastic collisions between neutrons and hydrogen nuclei of the converter. The developed prototype equipment was tested with shielded radiation sources. The low background of the detector and insensitivity to high-energy gamma rays above 1 MeV are advantages when the detection of neutron-emitting nuclear materials is of importance. In the case of a (252)Cf neutron spectrum, the intrinsic efficiency of fast neutron detection was determined to be 2.5×10(-4), whereas three-fold greater efficiency was obtained for a (241)AmBe neutron spectrum.

  1. Ohmic and rectifying contacts on bulk AlN for radiation detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Erlbacher, Tobias; Kallinger, Birgit; Meissner, Elke; Bauer, Anton J. [Fraunhofer Institute for Integrated Systems and Device Technology, Schottkystrasse 10, 91058 Erlangen (Germany); Bickermann, Matthias [CrystAl-N GmbH, Am Weichselgarten 7, 91058 Erlangen (Germany); Department of Materials Science 6 (I-MEET), University of Erlangen-Nuernberg, Martensstrasse 7, 91058 Erlangen (Germany); Frey, Lothar [Fraunhofer Institute for Integrated Systems and Device Technology, Schottkystrasse 10, 91058 Erlangen (Germany); Chair of Electron Devices, University of Erlangen-Nuernberg, Cauerstrasse 6, 91058 Erlangen (Germany)

    2012-03-15

    In this paper we report on ohmic and rectifying contacts fabricated on undoped bulk AlN substrates for radiation detector applications. The ohmic Ni contacts exhibit negligible contact resistances. Current conduction is dominated by field enhanced thermal emission from traps 0.4 to 0.6 eV below the conduction band. The Pt Schottky contacts show excellent rectifying behaviour. In forward conduction, device current is again limited by the Poole-Frenkel effect. The Schottky barrier features very low reverse leakage currents, and voltages of up to -200 V can be applied. The capability of bulk AlN for radiation detectors at room temperature is demonstrated. Suitability is deduced from both X-ray absorption experiments and low reverse leakage currents of the fabricated Schottky diodes. Additionally, the AlN substrate is almost blind to sun light due to its wide band gap. Still, reduction of recombination sites in AlN is required to achieve maximum detector performance. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Response function of semiconductor detectors, Ge and Si(Li); Funcao resposta de detectores semicondutores, Ge e Si(Li)

    Energy Technology Data Exchange (ETDEWEB)

    Zevallos Chavez, Juan Yury

    2003-07-01

    The Response Function (RF) for Ge and Si(Li) semiconductor detectors was obtained. The RF was calculated for five detectors, four Hp Ge with active volumes of 89 cm{sup 3} , 50 cm{sup 3} , 8 cm{sup 3} and 5 cm{sup 3}, and one Si(Li) with 0.143 cm{sup 3} of active volume. The interval of energy studied ranged from 6 keV up to 1.5 MeV. Two kinds of studies were done in this work. The first one was the RF dependence with the detection geometry. Here the calculation of the RF for a geometry named as simple and an extrapolation of that RF, were both done. The extrapolation process analyzed both, spectra obtained with a shielding geometry and spectra where the source-detector distance was modified. The second one was the RF dependence with the detection electronics. This study was done varying the shaping time of the pulse in the detection electronics. The purpose was to verify the effect of the ballistic deficit in the resolution of the detector. This effect was not observed. The RF components that describe the region of the total absorption of the energy of the incident photons, and the partial absorption of this energy, were both treated. In particular, empirical functions were proposed for the treatment of both, the multiple scattering originated in the detector (crystal), and the photon scattering originated in materials of the neighborhood of the crystal. Another study involving Monte Carlo simulations was also done in order to comprehend the photon scattering structures produced in an iron shield. A deconvolution method is suggested, for spectra related to scattered radiation in order to assess the dose delivered to the scatterer. (author)

  3. Limits on uranium and thorium bulk content in GERDA Phase I detectors

    CERN Document Server

    Agostini, M; Bakalyarov, A M; Balata, M; Barabanov, I; Baudis, L; Bauer, C; Becerici-Schmidt, N; Bellotti, E; Belogurov, S; Belyaev, S T; Benato, G; Bettini, A; Bezrukov, L; Bode, T; Borowicz, D; Brudanin, V; Brugnera, R; Caldwell, A; Cattadori, C; Chernogorov, A; D'Andrea, V; Demidova, E V; di Vacri, A; Domula, A; Doroshkevich, E; Egorov, V; Falkenstein, R; Fedorova, O; Freund, K; Frodyma, N; Gangapshev, A; Garfagnini, A; Grabmayr, P; Gurentsov, V; Gusev, K; Hakemüller, J; Hegai, A; Heisel, M; Hemmer, S; Hofmann, W; Hult, M; Inzhechik, L V; Csathy, J Janicsko; Jochum, J; Junker, M; Kazalov, V; Kihm, T; Kirpichnikov, I V; Kirsch, A; Kish, A; Klimenko, A; Kneißl, R; Knöpfle, K T; Kochetov, O; Kornoukhov, V N; Kuzminov, V V; Laubenstein, M; Lazzaro, A; Lebedev, V I; Lehnert, B; Liao, H Y; Lindner, M; Lippi, I; Lubashevskiy, A; Lubsandorzhiev, B; Lutter, G; Macolino, C; Majorovits, B; Maneschg, W; Medinaceli, E; Mingazheva, R; Misiaszek, M; Moseev, P; Nemchenok, I; Palioselitis, D; Panas, K; Pandola, L; Pelczar, K; Pullia, A; Riboldi, S; Rumyantseva, N; Sada, C; Salamida, F; Salathe, M; Schmitt, C; Schneider, B; Schönert, S; Schreiner, J; Schütz, A -K; Schulz, O; Schwingenheuer, B; Selivanenko, O; Shevchik, E; Shirchenko, M; Simgen, H; Smolnikov, A; Stanco, L; Stepaniuk, M; Vanhoefer, L; Vasenko, A A; Veresnikova, A; von Sturm, K; Wagner, V; Walter, M; Wegmann, A; Wester, T; Wiesinger, C; Wojcik, M; Yanovich, E; Zhitnikov, I; Zhukov, S V; Zinatulina, D; Zuber, K; Zuzel, G

    2016-01-01

    Internal contaminations of $^{238}$U, $^{235}$U and $^{232}$Th in the bulk of high purity germanium detectors are potential backgrounds for experiments searching for neutrinoless double beta decay of $^{76}$Ge. The data from GERDA Phase~I have been analyzed for alpha events from the decay chain of these contaminations by looking for full decay chains and for time correlations between successive decays in the same detector. No candidate events for a full chain have been found. Upper limits on the activities in the range of a few nBq/kg for $^{226}$Ra, $^{227}$Ac and $^{228}$Th, the long-lived daughter nuclides of $^{238}$U, $^{235}$U and $^{232}$Th, respectively, have been derived. With these upper limits a background index in the energy region of interest from $^{226}$Ra and $^{228}$Th contamination is estimated which satisfies the prerequisites of a future ton scale germanium double beta decay experiment.

  4. Bulk charge carrier transport in push-pull type organic semiconductor.

    Science.gov (United States)

    Karak, Supravat; Liu, Feng; Russell, Thomas P; Duzhko, Volodimyr V

    2014-12-10

    Operation of organic electronic and optoelectronic devices relies on charge transport properties of active layer materials. The magnitude of charge carrier mobility, a key efficiency metrics of charge transport properties, is determined by the chemical structure of molecular units and their crystallographic packing motifs, as well as strongly depends on the film fabrication approaches that produce films with different degrees of anisotropy and structural order. Probed by the time-of-flight and grazing incidence X-ray diffraction techniques, bulk charge carrier transport, molecular packing, and film morphology in different structural phases of push-pull type organic semiconductor, 7,7'-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene-2,6-diyl)bis(6-fluoro-4-(5'-hexyl-[2,2'-bithiophen]-5yl)benzo[c][1,2,5] thiadiazole), one of the most efficient small-molecule photovoltaic materials to-date, are described herein. In the isotropic phase, the material is ambipolar with high mobilities for a fluid state. The electron and hole mobilities at the phase onset at 210.78 °C are 1.0 × 10(-3) cm(2)/(V s) and 6.5 × 10(-4) cm(2)/(V s), respectively. Analysis of the temperature and electric field dependences of the mobilities in the framework of Gaussian disorder formalism suggests larger energetic and positional disorder for electron transport sites. Below 210 °C, crystallization into a polycrystalline film with a triclinic unit cell symmetry and high degree of anisotropy leads to a 10-fold increase of hole mobility. The mobility is limited by the charge transfer along the direction of branched alkyl side chains. Below 90 °C, faster cooling rates produce even higher hole mobilities up to 2 × 10(-2) cm(2)/(V s) at 25 °C because of the more isotropic orientations of crystalline domains. These properties facilitate in understanding efficient material performance in photovoltaic devices and will guide further development of materials and devices.

  5. Detection of secondary electrons with pixelated hybrid semiconductor detectors; Sekundaerelektronennachweis mit pixelierten hybriden Halbleiterdetektoren

    Energy Technology Data Exchange (ETDEWEB)

    Gebert, Ulrike Sonja

    2011-09-14

    Within the scope of this thesis, secondary electrons were detected with a pixelated semiconductor detector named Timepix. The Timepix detector consists of electronics and a sensor made from a semiconductor material. The connection of sensor and electronics is done for each pixel individually using bump bonds. Electrons with energies above 3 keV can be detected with the sensor. One electron produces a certain amount of electron-hole pairs according to its energy. The charge then drifts along an electric field to the pixel electronics, where it induces an electric signal. Even without a sensor it is possible to detect an electric signal from approximately 1000 electrons directly in the pixel electronics. Two different detector systems to detect secondary electrons using the Timepix detector were investigated during this thesis. First of all, a hybrid photon detector (HPD) was used to detect single photoelectrons. The HPD consists of a vacuum vessel with an entrance window and a cesium iodine photocathode at the inner surface of the window. Photoelectrons are released from the photocathode by incident light and are accelerated in an electric field towards the Timepix detector, where the point of interaction and the arrival time of the electron is determined. With a proximity focusing setup, a time resolution of 12 ns (with an acceleration voltage of 20 kV between photocathode and Timepix detector) was obtained. The HPD examined in this thesis showed a strong dependence of the dark rate form the acceleration voltage and the pressure in the vacuum vessel. At a pressure of few 10{sup -5} mbar and an acceleration voltage of 20 kV, the dark rate was about 800 Hz per mm{sup 2} area of the read out photocathode. One possibility to reduce the dark rate is to identify ion feedback events. With a slightly modified setup it was possible to reduce the dark rate to 0.5 Hz/mm{sup 2}. To achieve this, a new photocathode was mounted in a shorter distance to the detector. The

  6. Perfluorocarbons and their use in Cooling Systems for Semiconductor Particle Detectors

    CERN Document Server

    Vacek, V; Ilie, S; Lindsay, S

    2000-01-01

    We report on the development of evaporative fluorocarbon cooling for the semiconductor pixel and micro-strip sensors of inner tracking detector of the ATLAS experiment at the future CERN Large Hadron Collider (LHC). We proceeded with studies using perfluoro-n-propane (3M-"PFG 5030"; C3F8), perfluoro-n-butane (3M-"PFG 5040"; C4F10), trifluoro-iodo-methane (CF3I) and custom C3F8/C4F10 mixtures. Certain thermo-physical properties had to be verified for these fluids.

  7. Impact of Molecular Orientation and Packing Density on Electronic Polarization in the Bulk and at Surfaces of Organic Semiconductors.

    Science.gov (United States)

    Ryno, Sean M; Risko, Chad; Brédas, Jean-Luc

    2016-06-08

    The polarizable environment surrounding charge carriers in organic semiconductors impacts the efficiency of the charge transport process. Here, we consider two representative organic semiconductors, tetracene and rubrene, and evaluate their polarization energies in the bulk and at the organic-vacuum interface using a polarizable force field that accounts for induced-dipole and quadrupole interactions. Though both oligoacenes pack in a herringbone motif, the tetraphenyl substituents on the tetracene backbone of rubrene alter greatly the nature of the packing. The resulting change in relative orientations of neighboring molecules is found to reduce the bulk polarization energy of holes in rubrene by some 0.3 eV when compared to tetracene. The consideration of model organic-vacuum interfaces highlights the significant variation in the electrostatic environment for a charge carrier at a surface although the net change in polarization energy is small; interestingly, the environment of a charge even just one layer removed from the surface can be viewed already as representative of the bulk. Overall, it is found that in these herringbone-type layered crystals the polarization energy has a much stronger dependence on the intralayer packing density than interlayer packing density.

  8. Impact of Molecular Orientation and Packing Density on Electronic Polarization in the Bulk and at Surfaces of Organic Semiconductors

    KAUST Repository

    Ryno, Sean M.

    2016-05-16

    The polarizable environment surrounding charge carriers in organic semiconductors impacts the efficiency of the charge transport process. Here, we consider two representative organic semiconductors, tetracene and rubrene, and evaluate their polarization energies in the bulk and at the organic-vacuum interface using a polarizable force field that accounts for induced-dipole and quadrupole interactions. Though both oligoacenes pack in a herringbone motif, the tetraphenyl substituents on the tetracene backbone of rubrene alter greatly the nature of the packing. The resulting change in relative orientations of neighboring molecules is found to reduce the bulk polarization energy of holes in rubrene by some 0.3 eV when compared to tetracene. The consideration of model organic-vacuum interfaces highlights the significant variation in the electrostatic environment for a charge carrier at a surface although the net change in polarization energy is small; interestingly, the environment of a charge even just one layer removed from the surface can be viewed already as representative of the bulk. Overall, it is found that in these herringbone-type layered crystals the polarization energy has a much stronger dependence on the intralayer packing density than interlayer packing density.

  9. Very Low-Power Consumption Analog Pulse Processing ASIC for Semiconductor Radiation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, K.O.; Lund, J.C.; Brunett, B.A.; Laguna, G.R.; Clements, J.W.

    1999-08-23

    We describe a very-low power consumption circuit for processing the pulses from a semiconductor radiation detector. The circuit was designed for use with a cadmium zinc telluride (CZT) detector for unattended monitoring of stored nuclear materials. The device is intended to be battery powered and operate at low duty-cycles over a long period of time. This system will provide adequate performance for medium resolution gamma-ray pulse-height spectroscopy applications. The circuit incorporates the functions of a charge sensitive preamplifier, shaping amplifier, and peak sample and hold circuit. An application specific integrated circuit (ASIC) version of the design has been designed, built and tested. With the exception of the input field effect transistor (FET), the circuit is constructed using bipolar components. In this paper the design philosophy and measured performance characteristics of the circuit are described.

  10. Development of a novel 2D position-sensitive semiconductor detector concept

    CERN Document Server

    Bassignana, D; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I

    2012-01-01

    A novel 2D position-sensitive semiconductor detector concept has been developed employing resistive electrodes in a single-sided silicon microstrip sensor. The resistive charge division method has been implemented reading out each strip at both ends, in order to get the second coordinate of an ionizing event along the strips length. Two generations of prototypes, with different layout, have been produced and characterized using a pulsed near infra-red laser. The feasibility of the resistive charge division method in silicon microstrip detectors has been demonstrated and the possibility of single-chip readout of the device has been investigated. Experimental data were compared with the theoretical expectations and the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The agreement between experimental and simulation results validates the developed simulation as a tool for the optimization of future sensor prototypes.

  11. Characterization of a large CdZnTe coplanar quad-grid semiconductor detector

    CERN Document Server

    Ebert, Joachim; Gehre, Daniel; Hagner, Caren; Heidrich, Nadine; Klingenberg, Rainer; Kröninger, Kevin; Nitsch, Christian; Oldorf, Christian; Quante, Thomas; Rajek, Silke; Rebber, Henning; Rohatsch, Katja; Tebrügge, Jan; Temminghoff, Robert; Theinert, Robert; Timm, Jan; Wonsak, Björn; Zatschler, Stefan; Zuber, Kai

    2015-01-01

    The COBRA collaboration aims to search for neutrinoless double beta-decay of $^{116}$Cd. A demonstrator setup with 64 CdZnTe semiconductor detectors, each with a volume of 1cm$^3$, is currently being operated at the LNGS underground laboratory in Italy. This paper reports on the characterization of a large (2 $\\times$ 2 $\\times$ 1.5)cm$^3$ CdZnTe detector with a new coplanar-grid design for applications in $\\gamma$-ray spectroscopy and low-background operation. Several studies of electric properties as well as of the spectrometric performance, like energy response and resolution, are conducted. Furthermore, measurements including investigating the operational stability and a possibility to identify multiple-scattered photons are presented.

  12. Development and characterization of the lead iodide semiconductor detector; Desenvolvimento e caracterizacao do detector semicondutor de iodeto de chumbo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Icimone Braga de

    2001-07-01

    A methodology for purification and growth of PbI{sub 2} crystal as well as for its characterization as a room temperature radiation detector was developed in this work. Commercial salts were purified using the zone refining method and, for the purified material growth, the Bridgman method was used. To calculate the purification efficiency, studies of the decrease impurities concentrations were made in the salts and in three sections of the materials purified, using the neutron activation analysis technique. The results showed that the impurities segregate preferentially in the ingot final section. A significant decrease of the impurities concentration in function of the purification pass number was observed. The grown crystals presented good crystalline quality according to the results of the X-ray diffraction analysis. To evaluate the crystal as a semiconductor detector, measurements of dark leakage current, resistivity and the response of ({sup 241}Am) alpha particle and ({sup 241}Am, {sup 57}Co, {sup 133}Ba and {sup 137}Cs) gamma rays were carried out. The radiation response is strongly dependent on the crystals purity. The crystals purified with 500 passes exhibited energy resolution of 10% for {sup 241} Am alpha particle and the gamma rays resolution was compatible with the literature. The photosensibility of the PbI{sub 2} crystal found in the wavelength from 400 to 600 nm range suggests an another application at this crystal as a photodetector to be coupled to scintillators. (author)

  13. Enhanced infrared magneto-optical response of the nonmagnetic semiconductor BiTeI driven by bulk Rashba splitting.

    Science.gov (United States)

    Demkó, L; Schober, G A H; Kocsis, V; Bahramy, M S; Murakawa, H; Lee, J S; Kézsmárki, I; Arita, R; Nagaosa, N; Tokura, Y

    2012-10-19

    We study the magneto-optical (MO) response of the polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being nonmagnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (up to 3 T). Our first-principles calculations show that the enhanced MO response of BiTeI comes mainly from the intraband transitions between the Rashba-split bulk conduction bands. These transitions connecting electronic states with opposite spin directions become active due to the presence of strong spin-orbit interaction and give rise to distinct features in the MO spectra with a systematic doping dependence. We predict an even more pronounced enhancement in the low-energy MO response and dc Hall effect near the crossing (Dirac) point of the conduction bands.

  14. Non equilibrium optical properties in semiconductors from first--principles: a combined theoretical and experimental study of bulk silicon

    CERN Document Server

    Sangalli, Davide; Manzoni, Cristian; Cerullo, Giulio; Marini, Andrea

    2016-01-01

    The calculation of the equilibrium optical properties of bulk silicon by using the Bethe--Salpeter equation solved in the Kohn--Sham basis represents a cornerstone in the development of an ab--initio approach to the optical and electronic properties of materials. Nevertheless calculations of the {\\em transient} optical spectrum using the same efficient and successful scheme are scarce. We report, here, a joint theoretical and experimental study of the transient reflectivity spectrum of bulk silicon. Femtosecond transient reflectivity is compared to a parameter--free calculation based on the non--equilibrium Bethe--Salpeter equation. By providing an accurate description of the experimental results we disclose the different phenomena that determine the transient optical response of a semiconductor. We give a parameter--free interpretation of concepts like bleaching, photo--induced absorption and stimulated emission, beyond the Fermi golden rule. We also introduce the concept of optical gap renormalization, as a...

  15. Recent advances in Tl Br, Cd Te and CdZnTe semiconductor radiation detectors: a review

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Icimone B. [Universidade Bandeirante (UNIBAN), Sao Paulo, SP (Brazil)

    2011-07-01

    The success in the development of radiation spectrometers operating at room temperature is based on many years of effort on the part of large numbers of workers around the world. These individuals have contributed to the understanding of the fundamental materials issues associated with the growth of semiconductors for this application, the development of device fabrication and processing technology, and advances in low noise electronics and pulse processing. Progress in this field continues at an accelerated pace, as in evidenced by the improvements in detector performance and by the growing number of commercial products. Thus, the last years have been seen continued effort in the development of room temperature compound semiconductors devices. High-Z compound semiconductor detectors has been explored for high energy resolution, high detection efficiency and are of low cost. Compound semiconductors detectors are well suited for addressing needs of demanding applications such as bore hole logging where high operating temperature are encountered. In this work recent developments in semiconductors detectors were reviewed. This review concentrated on thallium bromide (TlBr), cadmium zinc telluride (CdZnTe) and cadmium telluride (CdTe) crystals detectors. TlBr has higher stopping power compared to common semiconductor materials because it has the higher photoelectric and total attenuation coefficients over wide energy range from 100 keV to 1 MeV. CdTe and CdZnTe detectors have several attractive features for detecting X-ray and low energy gamma ray. Their relatively large band gaps lead to a relatively low leakage current and offer an excellent energy resolution at room temperature. A literature survey and bibliography was also included. (author)

  16. Theory of the temperature dependent dielectric function of semiconductors: from bulk to surfaces. Application to GaAs and Si

    Energy Technology Data Exchange (ETDEWEB)

    Shkrebtii, Anatoli I.; Teatro, Timothy; Henderson, Laura [Faculty of Science, University of Ontario Institute of Technology, Simcoe Street North 2000, L1H 7K4 Oshawa (Canada); Ibrahim, Zahraa A. [Faculty of Science, University of Ontario Institute of Technology, Simcoe Street North 2000, L1H 7K4 Oshawa (Canada); Department of Physics, University of Toronto, M5S 1A7, Toronto (Canada); Richter, Wolfgang [Dipartimento di Fisica, Universita di Roma Tor Vergata, 00133 Rome (Italy); Institut fuer Festkoerperphysik, Technische Universitaet Berlin, 10623 Berlin (Germany); Lee, Martin J.G. [Department of Physics, University of Toronto, M5S 1A7, Toronto (Canada)

    2010-08-15

    A novel, efficient method for calculating the temperature dependencies of the linear dielectric functions of semiconductor systems and its application are presented. The method follows an intuitive and natural path with ab-initio finite temperature molecular dynamics providing the thermally perturbed atomic configurations, which are used as structural inputs for calculating the dielectric function. The effect of lattice dynamics, including quantum zero point vibration, on the electronic bands and dielectric function of crystalline (c-) GaAs and Si as well as hydrogenated amorphous Si (a-Si:H) is discussed. Our theoretical results for bulk c-GaAs and c-Si in the range from 0 to 1000 K are in good overall agreement with highly accurate ellipsometric measurements. The implementation of the method resolves a serious discrepancy in energy and line shape between experiment and the latest optical models, all of which neglect lattice dynamics, and provides information on the indirect gap and indirect optical transitions in c-Si. For a-Si:H, the calculated temperature dependent optical response combined with the vibrational spectroscopy provides detailed insight into electronic, dynamical properties, and stability of this important prototypical amorphous semiconductor material. At semiconductor surfaces, dynamical effects are expected to be even more pronounced due to reduced atom coordination and reconstruction. This is demonstrated for C(111) 2 x 1, an intensively studied but controversial surface of the quantum diamond crystal. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  17. Shubnikov-de Haas Oscillations in the Bulk Rashba Semiconductor BiTeI

    Energy Technology Data Exchange (ETDEWEB)

    Bell, C.; Bahramy, M.S.; Murakawa, H.; Checkelsky, J.G.; Arita, R.; Kaneko, Y.; Onose, Y.; Nagaosa, N.; Tokura, Y.; Hwang, H.Y.

    2012-07-11

    Bulk magnetoresistance quantum oscillations are observed in high quality single crystal samples of BiTeI. This compound shows an extremely large internal spin-orbit coupling, associated with the polarity of the alternating Bi, Te, and I layers perpendicular to the c-axis. The corresponding areas of the inner and outer Fermi surfaces around the A-point show good agreement with theoretical calculations, demonstrating that the intrinsic bulk Rashba-type splitting is nearly 360 meV, comparable to the largest spin-orbit coupling generated in heterostructures and at surfaces.

  18. Semiconductor-to-metal transition in the bulk of WSe2 upon potassium intercalation

    Science.gov (United States)

    Ahmad, Mushtaq; Müller, Eric; Habenicht, Carsten; Schuster, Roman; Knupfer, Martin; Büchner, Bernd

    2017-04-01

    We present electron energy-loss spectroscopic measurements of potassium (K) intercalated tungsten diselenide (WSe2). After exposure of pristine WSe2 films to potassium, we observe a charge carrier plasmon excitation at about 0.97 eV, which indicates a semiconductor-to-metal transition. Our data reveal the formation of one particular doped K-WSe2 phase. A Kramers–Kronig analysis allows the determination of the dielectric function and the estimation of the composition of K0.6WSe2. Momentum dependent measurements reveal a substantial plasmon dispersion to higher energies.

  19. Modeling direct band-to-band tunneling: From bulk to quantum-confined semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Nuñez, H.; Ziegler, A.; Luisier, M.; Schenk, A. [Integrated Systems Laboratory ETH Zürich, Gloriastrasse 35, 8092 Zürich (Switzerland)

    2015-06-21

    A rigorous framework to study direct band-to-band tunneling (BTBT) in homo- and hetero-junction semiconductor nanodevices is introduced. An interaction Hamiltonian coupling conduction and valence bands (CVBs) is derived using a multiband envelope method. A general form of the BTBT probability is then obtained from the linear response to the “CVBs interaction” that drives the system out of equilibrium. Simple expressions in terms of the one-electron spectral function are developed to compute the BTBT current in two- and three-dimensional semiconductor structures. Additionally, a two-band envelope equation based on the Flietner model of imaginary dispersion is proposed for the same purpose. In order to characterize their accuracy and differences, both approaches are compared with full-band, atomistic quantum transport simulations of Ge, InAs, and InAs-Si Esaki diodes. As another numerical application, the BTBT current in InAs-Si nanowire tunnel field-effect transistors is computed. It is found that both approaches agree with high accuracy. The first one is considerably easier to conceive and could be implemented straightforwardly in existing quantum transport tools based on the effective mass approximation to account for BTBT in nanodevices.

  20. Fast front-end electronics for semiconductor tracking detectors: Trends and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Rivetti, Angelo

    2014-11-21

    In the past few years, extensive research efforts pursued by both the industry and the academia have lead to major improvements in the performance of Analog to Digital Converters (ADCs) and Time to Digital Converters (TDCs). ADCs achieving 8–10 bit resolution, 50–100 MHz conversion frequency and less than 1 mW power consumption are the today's standard, while TDCs have reached sub-picosecond time resolution. These results have been made possible by architectural upgrades combined with the use of ultra deep submicron CMOS technologies with minimum feature size of 130 nm or smaller. Front-end ASICs in which a prompt digitization is followed by signal conditioning in the digital domain can now be envisaged also within the tight power budget typically available in high density tracking systems. Furthermore, tracking detectors embedding high resolution timing capabilities are gaining interest. In the paper, ADC's and TDC's developments which are of particular relevance for the design front-end electronics for semiconductor trackers are discussed along with the benefits and challenges of exploiting such high performance building blocks in implementing the next generation of ASICs for high granularity particle detectors.

  1. Fast front-end electronics for semiconductor tracking detectors: Trends and perspectives

    Science.gov (United States)

    Rivetti, Angelo

    2014-11-01

    In the past few years, extensive research efforts pursued by both the industry and the academia have lead to major improvements in the performance of Analog to Digital Converters (ADCs) and Time to Digital Converters (TDCs). ADCs achieving 8-10 bit resolution, 50-100 MHz conversion frequency and less than 1 mW power consumption are the today's standard, while TDCs have reached sub-picosecond time resolution. These results have been made possible by architectural upgrades combined with the use of ultra deep submicron CMOS technologies with minimum feature size of 130 nm or smaller. Front-end ASICs in which a prompt digitization is followed by signal conditioning in the digital domain can now be envisaged also within the tight power budget typically available in high density tracking systems. Furthermore, tracking detectors embedding high resolution timing capabilities are gaining interest. In the paper, ADC's and TDC's developments which are of particular relevance for the design front-end electronics for semiconductor trackers are discussed along with the benefits and challenges of exploiting such high performance building blocks in implementing the next generation of ASICs for high granularity particle detectors.

  2. Re-evaluation of Galileo Energetic Particle Detector data - a correction model and comparison to semiconductor detector dead-layer sensitivity losses using SRIM

    Science.gov (United States)

    Lee-Payne, Zoe Hannah

    2016-10-01

    The Energetic Particle Detector launched in 1989 on the Galileo satellite took data on the Jovian Particle environment for 8 years before its demise. Over the course of the mission the detectors in the Composition Measurement System (CMS) have visibly decayed with higher mass particles, specifically oxygen and sulphur, reading far lower energies at later epochs. By considering the non-steady accumulation of damage in the detector, as well as the operation of the priority channel data recording system in place on the EPD, an evolving correction can be made. The recalibration significance can be validated using a model of dead layer build-up in semiconductor detectors, based on SRIM results. The final aim is to assign an estimation dead-layer depth during the mission data recordings.

  3. Total energy, equation of state and bulk modulus of AlP, AlAs and AlSb semiconductors

    Indian Academy of Sciences (India)

    A R Jivani; H J Trivedi; P J Gajjar; A R Jani

    2005-01-01

    Recently proposed model potential which combines both linear and quadratic types of interactions is employed for the investigation of some properties like the total energy, equation of state and bulk modulus of AlP, AlAs and AlSb semiconductor compounds using higher-order perturbation theory. The model potential parameter is determined using zero pressure condition. The ratio of the covalent bonding term E cov to the second-order term 2 is 6.77% to 11.85% which shows that contribution from higher order terms are important for zinc-blende-type crystals. The calculated numerical results of the total energy, energy band gap at Jones-zone face and bulk modulus of these compounds are in good agreement with the experimental data and found much better than other such theoretical findings. We have also studied pressure–volume relations of these compounds. The present study is carried out using six different screening functions along with latest screening function proposed by Sarkar et al. It is found from the present study that effect of exchange and correlation is clearly distinguishable.

  4. High-efficiency microstructured semiconductor neutron detectors for direct {sup 3}He replacement

    Energy Technology Data Exchange (ETDEWEB)

    Fronk, R.G., E-mail: rfronk@ksu.edu [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Bellinger, S.L.; Henson, L.C. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Huddleston, D.E. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); Ochs, T.R. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Sobering, T.J. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, D.S. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2015-04-11

    High-efficiency Microstructured Semiconductor Neutron Detectors (MSNDs) have been tiled and arranged in a cylindrical form factor in order to serve as a direct replacement to aging and increasingly expensive {sup 3}He gas-filled proportional neutron detectors. Two 6-in long by 2-in diameter cylinders were constructed and populated with MSNDs which were then directly compared to a 4 atm Reuter Stokes {sup 3}He detector of the same dimensions. The Generation 1 MSND-based {sup 3}Helium-Replacement (HeRep Mk I) device contained sixty-four 1-cm{sup 2} active-area MSNDs, each with an intrinsic neutron detection efficiency of approximately 7%. A Generation 2 device (the HeRep Mk II) was populated with thirty 4-cm{sup 2} active-area MSNDs, with an intrinsic thermal neutron detection efficiency of approximately 30%. The MSNDs of each HeRep were integrated to count as a single device. The {sup 3}He proportional counter and the HeRep devices were tested while encased in a cylinder of high-density polyethylene measuring a total of 6-in by 9-in. The {sup 3}He counter and the HeRep Mk II were each placed 1 m from a 54-ng {sup 252}Cf source and tested for efficiency. The {sup 3}He proportional counter had a net count rate of 17.13±0.10 cps at 1 m. The HeRep Mk II device had a net count rate of 17.60±0.10 cps, amounting to 102.71±2.65% of the {sup 3}He gas counter while inside of the moderator. Outside of moderator, the {sup 3}He tube had a count rate of 3.35±0.05 cps and the HeRep Mk II device reported 3.19±05, amounting to 95.15±9.04% of the {sup 3}He neutron detector.

  5. Development of neutron/gamma generators and a polymer semiconductor detector for homeland security applications

    Science.gov (United States)

    King, Michael Joseph

    -energetic gamma generators that operate at low-acceleration energies and leverage neutron generator technologies. The dissertation focused on the experimental characterization of the generator performance and involved MCNPX simulations to evaluate and analyze the experimental results. The emission of the 11.7 MeV gamma-rays was observed to be slightly anisotropic and the gamma yield was measured to be 2.0*105 gamma/s-mA. The lanthanum hexaboride target suffered beam damage from a high power density beam; however, this may be overcome by sweeping the beam across a larger target area. The efficient detection of fast neutrons is vital to active interrogation techniques for the detection of both SNM and explosives. Novel organic semiconductors are air-stable, low-cost materials that demonstrate direct electronic particle detection. As part of the development of a pi-conjugated organic polymer for fast neutron detection, charge generation and collection properties were investigated. By devising a dual, thin-film detector test arrangement, charge collection was measured for high energy protons traversing the dual detector arrangement that allowed the creation of variable track lengths by tilting the detector. The results demonstrated that an increase in track length resulted in a decreased signal collection. This can be understood by assuming charge carrier transport along the track instead of along the field lines, which was made possible by the filling of traps. However, this charge collection mechanism may be insufficient to generate a useful signal. This dissertation has explored the viability of a new generation of radiation sources and detectors, where the newly developed ion source technologies and prototype generators will further enhance the capabilities of existing threat detection systems and promote the development of cutting-edge detection technologies.

  6. Status of radiation damage measurements in room temperature semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Franks, L.A.; James, R.B.

    1998-04-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI{sub 2}) is reviewed for the purpose of determining their applicability to space applications. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10{sup 10} p/cm{sup 2} and significant bulk leakage after 10{sup 12} p/cm{sup 2}. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 {times} 10{sup 9} p/cm{sup 2} in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum neutrons after fluences up to 10{sup 10} n/cm{sup 2}, although activation was evident. CT detectors show resolution losses after fluences of 3 {times} 10{sup 9} p/cm{sup 2} at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 {times} 10{sup 10} n/cm{sup 2}. Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10{sup 12} p/cm{sup 2} and with 1.5 GeV protons at fluences up to 1.2 {times} 10{sup 8} p/cm{sup 2}. Neutron exposures at 8 MeV have been reported at fluences up to 10{sup 15} n/cm{sup 2}. No radiation damage was found under these irradiation conditions.

  7. Monte Carlo simulation of semiconductor detector response to (222)Rn and (220)Rn environments.

    Science.gov (United States)

    Irlinger, J; Trinkl, S; Wielunksi, M; Tschiersch, J; Rühm, W

    2016-07-01

    A new electronic radon/thoron monitor employing semiconductor detectors based on a passive diffusion chamber design has been recently developed at the Helmholtz Zentrum München (HMGU). This device allows for acquisition of alpha particle energy spectra, in order to distinguish alpha particles originating from radon and radon progeny decays, as well as those originating from thoron and its progeny decays. A Monte-Carlo application is described which uses the Geant4 toolkit to simulate these alpha particle spectra. Reasonable agreement between measured and simulated spectra were obtained for both (220)Rn and (222)Rn, in the energy range between 1 and 10 MeV. Measured calibration factors could be reproduced by the simulation, given the uncertainties involved in the measurement and simulation. The simulated alpha particle spectra can now be used to interpret spectra measured in mixed radon/thoron atmospheres. The results agreed well with measurements performed in both radon and thoron gas environments. It is concluded that the developed simulation allows for an accurate prediction of calibration factors and alpha particle energy spectra.

  8. Calibration of semiconductor detectors in the 200-8500 keV range at VNIIM.

    Science.gov (United States)

    Tereshchenko, Evgeny E; Moiseev, Nikolay

    2012-09-01

    At the ionising radiation department of the D.I. Mendeleyev Institute for Metrology, a semiconductor detector was calibrated in the energy range 200-8500 keV using (n,2γ) and (n,γ) reactions. Separate cylindrical targets (77 mm diameter and 10mm height) were made from mercuric sulphate, sodium chloride and metallic titanium. A (252)Cf spontaneous fission neutron source, placed in 150 mm diameter polyethylene ball, was used to generate thermal neutrons. The optimal target dimensions were determined taking into account the thermal neutron cross-sections and gamma-radiation attenuations in the target materials. The influence of the background radiation induced by neutrons from the walls, floors and ceilings was also taken into account. The shapes of the efficiency curves for point and volume sources in the 200-8500 keV range have been investigated. The experimental results are in good agreement with Monte-Carlo calculations. The emission rate of the 6.13 MeV photons from a (238)Pu-(13)C source was determined with an expanded uncertainty, U(c), of 10% (k=2).

  9. Study on the effect of humidity and dust on leakage current of bulk micro-MEGAS detector

    CERN Document Server

    Wang, Bo; Qi, Hui-Rong; Liu, Jing; Zhang, Xin-Shuai; Zhang, Tian-Chong; Yi, Fu-Ting; Ou-Yang, Qun; Chen, Yuan-Bo

    2013-01-01

    In this paper, the effect of humidity and dust trapped in avalanche region on leakage current of bulk micro-MEGAS detector is studied. Pyralux PC1025 layers of DuPont are introduced in bulk technique and micro-MEGAS detector with pillars of 300{\\mu}m in diameter is fabricated. Leakage current is tested in air with different humidity. Silicon carbide powder and PMMA (polymethyl methacrylate) powder are added as dust to avalanche region. Leakage current with and without powder is tested in air and results are depicted in the same figure. Test results indicate that leakage current increases with both storage humidity and test humidity, and also increases when powder is introduced in avalanche region.

  10. Combined Bulk and Surface Radiation Damage Effects at Very High Fluences in Silicon Detectors: Measurements and TCAD Simulations

    CERN Document Server

    Moscatelli, F; Morozzi, A; Mendicino, Roberto; Betta, G -F Dalla; Bilei, G M

    2016-01-01

    In this work we propose a new combined TCAD radiation damage modelling scheme, featuring both bulk and surface radiation damage effects, for the analysis of silicon detectors aimed at the High Luminosity LHC. In particular, a surface damage model has been developed by introducing the relevant parameters (NOX, NIT) extracted from experimental measurements carried out on p-type substrate test structures after gamma irradiations at doses in the range 10-500 Mrad(Si). An extended bulk model, by considering impact ionization and deep-level cross-sections variation, was included as well. The model has been validated through the comparison of the simulation findings with experimental measurements carried out at very high fluences (2 10^16 1 MeV equivalent n/cm^2) thus fostering the application of this TCAD approach for the design and optimization of the new generation of silicon detectors to be used in future HEP experiments.

  11. Combined Bulk and Surface Radiation Damage Effects at Very High Fluences in Silicon Detectors: Measurements and TCAD Simulations

    CERN Document Server

    Moscatelli, F; Morozzi, A; Mendicino, R; Dalla Betta, G F; Bilei, G M

    2016-01-01

    In this work we propose a new combined TCAD radiation damage modelling scheme, featuring both bulk and surface radiation damage effects, for the analysis of silicon detectors aimed at the High Luminosity LHC. In particular, a surface damage model has been developed by introducing the relevant parameters (NOX, NIT) extracted from experimental measurements carried out on p-type substrate test structures after gamma irradiations at doses in the range 10-500 Mrad(Si). An extended bulk model, by considering impact ionization and deep-level cross-sections variation, was included as well. The model has been validated through the comparison of the simulation findings with experimental measurements carried out at very high fluences (2×1016 1 MeV equivalent n/cm2) thus fostering the application of this TCAD approach for the design and optimization of the new generation of silicon detectors to be used in future HEP experiments.

  12. Prompt gamma tests of LaBr{sub 3}:Ce and BGO detectors for detection of hydrogen, carbon and oxygen in bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A., E-mail: aanaqvi@kfupm.edu.sa [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Matouq, Fares A.; Khiari, F.Z. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Isab, A.A. [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Rehman, Khateeb-ur; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2012-08-21

    Prompt gamma ray tests of cylindrical lanthanum halide (LaBr{sub 3}:Ce) and bismuth germanate (BGO) gamma ray detectors have been carried out for detection of hydrogen, carbon and oxygen concentrations in bulk samples via inelastic scattering of neutrons using a 14 MeV neutron-based prompt gamma neutron activation analysis setup. Regardless of its intrinsic activity, the LaBr{sub 3}:Ce detector showed superior performance than the BGO detector for the detection of hydrogen, carbon and oxygen concentrations in benzene, water, toluene, propanol, ethanol and methanol bulk samples. The BGO detector has a large concentration of oxygen in its detector material and is consequently less sensitive for oxygen detection in bulk samples. Hence, it is not a suitable choice for oxygen determination in bulk samples.

  13. Design and operation of a 2-D thin-film semiconductor neutron detector array for use as a beamport monitor

    Energy Technology Data Exchange (ETDEWEB)

    Unruh, Troy C.; Bellinger, Steven L. [SMART Laboratory, Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States); Huddleston, David E. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McNeil, Walter J.; Patterson, Eric [SMART Laboratory, Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States); Sobering, Tim J. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [SMART Laboratory, Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: mcgregor@ksu.edu

    2009-06-01

    Silicon-based diodes coated with a thin film of neutron reactive materials have been shown to produce excellent low-efficiency neutron detectors. This work employs the same technology, but groups 25 equally sized and spaced diodes on a single 29 mm by 29 mm substrate. A 5x5 array was fabricated and coated with a thin film of {sup 6}LiF for use as a low-efficiency neutron beam monitor. The 5x5 neutron detector array is coupled to an array of amplifiers, allowing the response to be interpreted using a LabVIEW FPGA. The 5x5 array has been characterized in a diffracted neutron beam. This work is a part of on-going research to develop various designs of high- and low-efficiency semiconductor neutron detectors.

  14. Photoprecursor Approach Enables Preparation of Well-Performing Bulk-Heterojunction Layers Comprising a Highly Aggregating Molecular Semiconductor.

    Science.gov (United States)

    Suzuki, Mitsuharu; Yamaguchi, Yuji; Takahashi, Kohei; Takahira, Katsuya; Koganezawa, Tomoyuki; Masuo, Sadahiro; Nakayama, Ken-ichi; Yamada, Hiroko

    2016-04-06

    Active-layer morphology critically affects the performance of organic photovoltaic cells, and thus its optimization is a key toward the achievement of high-efficiency devices. However, the optimization of active-layer morphology is sometimes challenging because of the intrinsic properties of materials such as strong self-aggregating nature or low miscibility. This study postulates that the "photoprecursor approach" can serve as an effective means to prepare well-performing bulk-heterojunction (BHJ) layers containing highly aggregating molecular semiconductors. In the photoprecursor approach, a photoreactive precursor compound is solution-deposited and then converted in situ to a semiconducting material. This study employs 2,6-di(2-thienyl)anthracene (DTA) and [6,6]-phenyl-C71-butyric acid methyl ester as p- and n-type materials, respectively, in which DTA is generated by the photoprecursor approach from the corresponding α-diketone-type derivative DTADK. When only chloroform is used as a cast solvent, the photovoltaic performance of the resulting BHJ films is severely limited because of unfavorable film morphology. The addition of a high-boiling-point cosolvent, o-dichlorobenzene (o-DCB), to the cast solution leads to significant improvement such that the resulting active layers afford up to approximately 5 times higher power conversion efficiencies. The film structure is investigated by two-dimensional grazing-incident wide-angle X-ray diffraction, atomic force microscopy, and fluorescence microspectroscopy to demonstrate that the use of o-DCB leads to improvement in film crystallinity and increase in charge-carrier generation efficiency. The change in film structure is assumed to originate from dynamic molecular motion enabled by the existence of solvent during the in situ photoreaction. The unique features of the photoprecursor approach will be beneficial in extending the material and processing scopes for the development of organic thin-film devices.

  15. MCNPX simulations of the silicon carbide semiconductor detector response to fast neutrons from D-T nuclear reaction

    Science.gov (United States)

    Sedlačková, Katarína; Šagátová, Andrea; Zat'ko, Bohumír; Nečas, Vladimír; Solar, Michael; Granja, Carlos

    2016-09-01

    Silicon Carbide (SiC) has been long recognized as a suitable semiconductor material for use in nuclear radiation detectors of high-energy charged particles, gamma rays, X-rays and neutrons. The nuclear interactions occurring in the semiconductor are complex and can be quantified using a Monte Carlo-based computer code. In this work, the MCNPX (Monte Carlo N-Particle eXtended) code was employed to support detector design and analysis. MCNPX is widely used to simulate interaction of radiation with matter and supports the transport of 34 particle types including heavy ions in broad energy ranges. The code also supports complex 3D geometries and both nuclear data tables and physics models. In our model, monoenergetic neutrons from D-T nuclear reaction were assumed as a source of fast neutrons. Their energy varied between 16 and 18.2 MeV, according to the accelerating voltage of the deuterons participating in D-T reaction. First, the simulations were used to calculate the optimum thickness of the reactive film composed of High Density PolyEthylene (HDPE), which converts neutral particles to charged particles and thusly enhancing detection efficiency. The dependency of the optimal thickness of the HDPE layer on the energy of the incident neutrons has been shown for the inspected energy range. Further, from the energy deposited by secondary charged particles and recoiled ions, the detector response was modeled and the effect of the conversion layer on detector response was demonstrated. The results from the simulations were compared with experimental data obtained for a detector covered by a 600 and 1300 μm thick conversion layer. Some limitations of the simulations using MCNPX code are also discussed.

  16. Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector.

    Science.gov (United States)

    Smith, Richard J; Light, Roger A; Sharples, Steve D; Johnston, Nicholas S; Pitter, Mark C; Somekh, Mike G

    2010-02-01

    This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

  17. Theoretical investigation of the excitonic semiconductor response for varying material thickness: Transition from quantum well to bulk

    DEFF Research Database (Denmark)

    Bischoff, Svend; Knorr, A; Koch, S.W.

    1997-01-01

    For semiconductor slabs with thicknesses varying from the two-dimensional to the three-dimensional limit the linear optical response is calculated numerically by solving the semiconductor Maxwell-Bloch equations. For short-pulse excitation the spatiotemporal dynamics of the electronic mode...

  18. SOI metal-oxide-semiconductor field-effect transistor photon detector based on single-hole counting.

    Science.gov (United States)

    Du, Wei; Inokawa, Hiroshi; Satoh, Hiroaki; Ono, Atsushi

    2011-08-01

    In this Letter, a scaled-down silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) is characterized as a photon detector, where photogenerated individual holes are trapped below the negatively biased gate and modulate stepwise the electron current flowing in the bottom channel induced by the positive substrate bias. The output waveforms exhibit clear separation of current levels corresponding to different numbers of trapped holes. Considering this capability of single-hole counting, a small dark count of less than 0.02 s(-1) at room temperature, and low operation voltage of 1 V, SOI MOSFET could be a unique photon-number-resolving detector if the small quantum efficiency were improved.

  19. Design of a high-resolution small-animal SPECT-CT system sharing a CdTe semiconductor detector

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Hyun-Ju; Lee, Young-Jin; Lee, Seung-Wan; Cho, Hyo-Min; Choi, Yu-Na; Kim, Hee-Joung [Yonsei University, Wonju (Korea, Republic of)

    2012-07-15

    A single photon emission computed tomography (SPECT) system with a co-registered X-y computed tomography (CT) system allows the convergence of functional information and morphologic information. The localization of radio pharmaceuticals on a SPECT can be enhanced by combining the SPECT with an anatomical modality, such as X-ray CT. Gamma-ray imaging for nuclear medicine devices and X-ray imaging systems for diagnostics has recently been developed based on semiconductor detectors, and semiconductor detector materials such as cadmium telluride (CdTe) or cadmium zinc telluride (CZT) are available for both X-ray and gamma-ray systems for small animal imaging. CdTe or CZT detectors provide strong absorption and high detection efficiency of high energy X-ray and gamma-ray photons because of their large atomic numbers. In this study, a pinhole collimator SPECT system sharing a cadmium telluride (CdTe) detector with a CT was designed. The GEANT4 application for tomographic emission (GATE) v.6.1 was used for the simulation. The pinhole collimator was designed to obtain a high spatial resolution of the SPECT system. The acquisition time for each projection was 40 seconds, and 60 projections were obtained for tomographic image acquisition. The reconstruction was performed using ordered subset expectation maximization (OS-EM) algorithms. The sensitivity and the spatial resolution were measured on the GATE simulation to evaluate the system characteristics. The spatial resolution of the system calculated from the FWHM of Gaussian fitted PSF curve was 0.69 mm, and the sensitivity of the system was measured to be 0.354 cps/kBq by using a Tc-99m point source of 1 MBq for 800 seconds. A phantom study was performed to verify the design of the dual imaging modality system. The system will be built as designed, and it can be applied as a pre-clinical imaging system.

  20. Sample dependent response of a LaCl{sub 3}:Ce detector in prompt gamma neutron activation analysis of bulk hydrocarbon samples

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A., E-mail: aanaqvi@kfupm.edu.sa [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Matouq, Faris A.; Khiari, F.Z. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Isab, A.A. [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Khateeb-ur-Rehman,; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2013-08-11

    The response of a LaCl{sub 3}:Ce detector has been found to depend upon the hydrogen content of bulk samples in prompt gamma analysis using 14 MeV neutron inelastic scattering. The moderation of 14 MeV neutrons from hydrogen in the bulk sample produces thermal neutrons around the sample which ultimately excite chlorine capture gamma rays in the LaCl{sub 3}:Ce detector material. Interference of 6.11 MeV chlorine gamma rays from the detector itself with 6.13 MeV oxygen gamma rays from the bulk samples makes the intensity of the 6.13 MeV oxygen gamma ray peak relatively insensitive to variations in oxygen concentration. The strong dependence of the 1.95 MeV doublet chlorine gamma ray yield on hydrogen content of the bulk samples confirms fast neutron moderation from hydrogen in the bulk samples as a major source of production of thermal neutrons and chlorine gamma rays in the LaCl{sub 3}:Ce detector material. Despite their poor oxygen detection capabilities, these detectors have nonetheless excellent detection capabilities for hydrogen and carbon in benzene, butyl alcohol, propanol, propanic acid, and formic acid bulk samples using 14 MeV neutron inelastic scattering.

  1. Effects of bulk and surface conductivity on the performance of CdZnTe pixel detectors

    DEFF Research Database (Denmark)

    Bolotnikov, A.E.; Chen, C.M.H.; Cook, W.R.;

    2002-01-01

    between the pixel contacts. When the grid is negatively biased, the strong electric field in the gaps between the pixels forces the electrons landing on the surface to move toward the contacts, preventing the charge loss. We have investigated these effects by using CZT pixel detectors indium bump...

  2. Li(Zn,Co,MnAs: A bulk form diluted magnetic semiconductor with Co and Mn co-doping at Zn sites

    Directory of Open Access Journals (Sweden)

    Bijuan Chen

    2016-11-01

    Full Text Available We report the synthesis and characterization of a series of bulk forms of diluted magnetic semiconductors Li(Zn1-x-yCoxMnyAs with a crystal structure close to that of III-V diluted magnetic semiconductor (Ga,MnAs. No ferromagnetic order occurs with single (Zn,Co or (Zn, Mn substitution in the parent compound LiZnAs. Only with co-doped Co and Mn ferromagnetic ordering can occur at the Curie temperature ∼40 K. The maximum saturation moment of the this system reached to 2.17μB/Mn, which is comparable to that of Li (Zn,MnAs. It is the first time that a diluted magnetic semiconductor with co-doping Co and Mn into Zn sites is achieved in “111” LiZnAs system, which could be utilized to investigate the basic science of ferromagnetism in diluted magnetic semiconductors. In addition, ferromagnetic Li(Zn,Co,MnAs, antiferromagnetic LiMnAs, and superconducting LiFeAs share square lattice at As layers, which may enable the development of novel heterojunction devices in the future.

  3. Li(Zn,Co,Mn)As: A bulk form diluted magnetic semiconductor with Co and Mn co-doping at Zn sites

    Science.gov (United States)

    Chen, Bijuan; Deng, Zheng; Li, Wenmin; Gao, Moran; Zhao, Jianfa; Zhao, Guoqiang; Yu, Shuang; Wang, Xiancheng; Liu, Qingqing; Jin, Changqing

    2016-11-01

    We report the synthesis and characterization of a series of bulk forms of diluted magnetic semiconductors Li(Zn1-x-yCoxMny)As with a crystal structure close to that of III-V diluted magnetic semiconductor (Ga,Mn)As. No ferromagnetic order occurs with single (Zn,Co) or (Zn, Mn) substitution in the parent compound LiZnAs. Only with co-doped Co and Mn ferromagnetic ordering can occur at the Curie temperature ˜40 K. The maximum saturation moment of the this system reached to 2.17 μB /Mn , which is comparable to that of Li (Zn,Mn)As. It is the first time that a diluted magnetic semiconductor with co-doping Co and Mn into Zn sites is achieved in "111" LiZnAs system, which could be utilized to investigate the basic science of ferromagnetism in diluted magnetic semiconductors. In addition, ferromagnetic Li(Zn,Co,Mn)As, antiferromagnetic LiMnAs, and superconducting LiFeAs share square lattice at As layers, which may enable the development of novel heterojunction devices in the future.

  4. Adsorption smoke detector made of thin-film metal-oxide semiconductor sensor

    CERN Document Server

    Adamian, A Z; Aroutiounian, V M

    2001-01-01

    Based on results of investigations of the thin-film smoke sensors made of Bi sub 2 O sub 3 , irresponsive to a change in relative humidity of the environment, an absorption smoke detector processing circuit, where investigated sensor is used as a sensitive element, is proposed. It is shown that such smoke detector is able to function reliably under conditions of high relative humidity of the environment (up to 100%) and it considerably exceeds the known smoke detectors by the sensitivity threshold.

  5. A combined surface and bulk TCAD damage model for the analysis of radiation detectors operating at HL-LHC fluences

    Science.gov (United States)

    Morozzi, A.; Passeri, D.; Moscatelli, F.; Dalla Betta, G.-F.; Bilei, G. M.

    2016-12-01

    In this work we present the development and the application of a new TCAD modelling scheme to simulate the effects of radiation damage on silicon radiation detectors at the very high fluence levels expected at High Luminosity LHC (up to 2 × 1016 1MeV n/cm2). In particular, we propose a combined approach for the analysis of the surface effects (oxide charge build-up and interface trap states introduction) as well as bulk effects (deep level traps and/or recombination centers introduction). Experimental measurements have been carried out aiming at: i) extraction from simple test structures of relevant parameters to be included within the TCAD model and ii) validation of the new modelling scheme through comparison with measurements of different test structures (e.g. different technologies) before and after irradiation. The good agreements between experimental measurements and simulation findings foster the suitability of the TCAD modelling approach as a predictive tool for investigating the radiation detector behavior at different fluences and operating conditions. This would allow the design and optimization of innovative 3D and planar silicon detectors for future HL-LHC High Energy Physics experiments.

  6. Optical characteristics of p-type GaAs-based semiconductors towards applications in photoemission infrared detectors

    Science.gov (United States)

    Lao, Y. F.; Perera, A. G. U.; Wang, H. L.; Zhao, J. H.; Jin, Y. J.; Zhang, D. H.

    2016-03-01

    Free-carrier effects in a p-type semiconductor including the intra-valence-band and inter-valence-band optical transitions are primarily responsible for its optical characteristics in infrared. Attention has been paid to the inter-valence-band transitions for the development of internal photoemission (IPE) mid-wave infrared (MWIR) photodetectors. The hole transition from the heavy-hole (HH) band to the spin-orbit split-off (SO) band has demonstrated potential applications for 3-5 μm detection without the need of cooling. However, the forbidden SO-HH transition at the Γ point (corresponding to a transition energy Δ0, which is the split-off gap between the HH and SO bands) creates a sharp drop around 3.6 μm in the spectral response of p-type GaAs/AlGaAs detectors. Here, we report a study on the optical characteristics of p-type GaAs-based semiconductors, including compressively strained InGaAs and GaAsSb, and a dilute magnetic semiconductor, GaMnAs. A model-independent fitting algorithm was used to derive the dielectric function from experimental reflection and transmission spectra. Results show that distinct absorption dip at Δ0 is observable in p-type InGaAs and GaAsSb, while GaMnAs displays enhanced absorption without degradation around Δ0. This implies the promise of using GaMnAs to develop MWIR IPE detectors. Discussions on the optical characteristics correlating with the valence-band structure and free-hole effects are presented.

  7. Bulk and Surface Event Identification in p-type Germanium Detectors

    CERN Document Server

    Yang, L T; Jia, L P; Jiang, H; Li, J; Lin, F K; Lin, S T; Liu, S K; Ma, J L; Sharma, V; Singh, L; Singh, M K; Soma, A K; Yang, S W; Wang, L; Wang, Q; Wong, H T; Yue, Q; Zhao, W

    2016-01-01

    The p-type point-contact germanium detectors, due to its sub-keV sensitivities and low internal radioactivity background, are demonstrated to be competitive tools for light dark matter WIMPs searches and may have potential applications in neutrino physics. These detectors exhibit anomalous surface behavior, which has been characterized and dealt with in previous analysis. However, the analysis method rely on spectral shape assumptions and must use external calibration sources. In this report, we purpose an improved method, where in situ data could be used as calibration sources. Data from CDEX-1 and TEXONO experiments will be re-examined and the results are shown to be consistent with both analysis.

  8. Performance of an improved thermal neutron activation detector for buried bulk explosives

    Energy Technology Data Exchange (ETDEWEB)

    McFee, J.E., E-mail: jemcfee@gmail.com [Defence R and D Canada – Suffield, Medicine Hat (Canada); Faust, A.A. [Defence R and D Canada – Suffield, Medicine Hat (Canada); Andrews, H.R.; Clifford, E.T.H. [Bubble Technology Industries Inc., Chalk River (Canada); Mosquera, C.M. [Defence R and D Canada – Suffield, Medicine Hat (Canada)

    2013-06-01

    First generation thermal neutron activation (TNA) sensors, employing an isotopic source and NaI(Tl) gamma ray detectors, were deployed by Canadian Forces in 2002 as confirmation sensors on multi-sensor landmine detection systems. The second generation TNA detector is being developed with a number of improvements aimed at increasing sensitivity and facilitating ease of operation. Among these are an electronic neutron generator to increase sensitivity for deeper and horizontally displaced explosives; LaBr{sub 3}(Ce) scintillators, to improve time response and energy resolution; improved thermal and electronic stability; improved sensor head geometry to minimize spatial response nonuniformity; and more robust data processing. The sensor is described, with emphasis on the improvements. Experiments to characterize the performance of the second generation TNA in detecting buried landmines and improvised explosive devices (IEDs) hidden in culverts are described. Performance results, including comparisons between the performance of the first and second generation systems are presented.

  9. Measurements and TCAD Simulations of Bulk and Surface Radiation Damage Effects in Silicon Detectors

    CERN Document Server

    Moscatelli, F; Passeri, D; Bilei, G M; Servoli, L; Morozzi, A; Betta, G -F Dalla; Mendicino, R; Boscardin, M; Zorzi, N

    2016-01-01

    In this work we propose the application of a radiation damage model based on the introduction of deep level traps/recombination centers suitable for device level numerical simulation of radiation detectors at very high fluences (e.g. 1{\\div}2 10^16 1-MeV equivalent neutrons per square centimeter) combined with a surface damage model developed by using experimental parameters extracted from measurements from gamma irradiated p-type dedicated test structures.

  10. X-ray diffuse scattering for evaluation of wide bandgap semiconductor nuclear radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Goorsky, M.S. [University of Southern California, Los Angeles, CA (United States). Dept. of Mater. Sci. and Eng.; Yoon, H. [University of Southern California, Los Angeles, CA (United States). Dept. of Mater. Sci. and Eng.; Schieber, M. [Hebrew Univ., Jerusalem (Israel). Graduate Sch. of Appl. Sci.; James, R.B. [Sandia Nat. Labs., Livermore, CA (United States). Dept. 8347; McGregor, D.S. [Sandia Nat. Labs., Livermore, CA (United States). Dept. 8347; Natarajan, M. [TN Technol., Round Rock, TX (United States)

    1996-10-01

    The crystalline perfection of solid state radiation detectors was examined using triple axis x-ray diffraction. Triple axis techniques provide a means to analyze the origin of diffraction peak broadening: the effects of strain (due to deviations in alloy composition or stoichiometry) and lattice tilts (mosaic structure) can be separated. Cd{sub 1-x}Zn{sub x}Te (x{approx}0.1), HgI{sub 2}, and GaAs detector materials were studied. In the cases of Cd{sub 1-x}Zn{sub x}Te and HgI{sub 2} the crystalline properties of detectors with different spectral responses to {gamma}-radiation were determined. Increased mosaicity was universally found to be related to deteriorated detector properties. For Cd{sub 1-x}Zn{sub x}Te, detectors with poor performance possessed greater levels of diffuse scatter due to lattice tilts than did high quality detectors. For GaAs, low angle grain boundaries were attributed to impaired detector performance. Additionally, in large HgI{sub 2} detectors, deviations from stoichiometry were also related to reduced performance. Interestingly, HgI{sub 2} detectors which possessed a sharp spectral response to {gamma}-radiation but also showed polarization were of comparable crystallinity to those detectors which did not exhibit polarization effects. This initial analysis suggests that polarization is related to native point defects or chemical impurities which do not significantly alter the crystallinity of the material. Overall, within a given class of materials, improved detector performance (better spectral response) always correlated with better material quality. (orig.).

  11. Electrical analysis of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors on flexible bulk mono-crystalline silicon

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-06-01

    We report on the electrical study of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors (MOSCAPs) on a flexible ultra-thin (25 μm) silicon fabric which is peeled off using a CMOS compatible process from a standard bulk mono-crystalline silicon substrate. A lifetime projection is extracted using statistical analysis of the ramping voltage (Vramp) breakdown and time dependent dielectric breakdown data. The obtained flexible MOSCAPs operational voltages satisfying the 10 years lifetime benchmark are compared to those of the control MOSCAPs, which are not peeled off from the silicon wafer. © 2014 IEEE.

  12. The ASACUSA Micromegas Tracker: A cylindrical, bulk Micromegas detector for antimatter research

    Energy Technology Data Exchange (ETDEWEB)

    Radics, B., E-mail: balint.radics@riken.jp; Nagata, Y.; Yamazaki, Y. [Atomic Physics Laboratory, RIKEN, Saitama 351-0198 (Japan); Ishikawa, S.; Kuroda, N.; Matsuda, Y. [Institute of Physics, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902 (Japan); Anfreville, M.; Aune, S.; Boyer, M.; Chateau, F.; Combet, M.; Granelli, R.; Legou, P.; Mandjavidze, I.; Procureur, S.; Riallot, M.; Vallage, B.; Vandenbroucke, M. [Irfu, CEA, Centre de Saclay, 91191 Gif sur Yvette (France)

    2015-08-15

    The ASACUSA Micromegas Tracker (AMT; ASACUSA: Atomic Spectroscopy and Collisions Using Slow Antiprotons) was designed to be able to reconstruct antiproton-nucleon annihilation vertices in three dimensions. The goal of this device is to study antihydrogen formation processes in the ASACUSA cusp trap, which was designed to synthesise a spin-polarised antihydrogen beam for precise tests of Charge, Parity, and Time (CPT) symmetry invariance. This paper discusses the structure and technical details of an AMT detector built into such an environment, its data acquisition system and the first performance with cosmic rays.

  13. Operational Experience of the ATLAS SemiConductor Tracker and Pixel Detector

    CERN Document Server

    Robinson, Dave; The ATLAS collaboration

    2016-01-01

    The tracking performance of the ATLAS detector relies critically on the silicon and gaseous tracking subsystems that form the ATLAS Inner Detector. Those subsystems have undergone significant hardware and software upgrades to meet the challenges imposed by the higher collision energy, pileup and luminosity that are being delivered by the LHC during Run2. The key status and performance metrics of the Pixel Detector and the Semi Conductor Tracker are summarised, and the operational experience and requirements to ensure optimum data quality and data taking efficiency are described.

  14. History of the "Detector Materials Engineering" Crystal Growth Process for Bulk Hg1- x Cd x Te

    Science.gov (United States)

    Higgins, W. M.; Nelson, D. A.; Roy, R. G.; Murosako, R. P.; Lancaster, R. A.; Tower, J.; Norton, P.

    2013-11-01

    This paper reviews the history and technology of a bulk Hg1- x Cd x Te crystal growth process that was developed in the early 1980s at Honeywell Electro-Optics Division (presently BAE Systems, Electronic Solutions). The crystal growth process name, DME, was an acronym for the department name: Detector Materials Engineering. This was an accelerated crucible rotation technique (ACRT) vertical traveling heater method growth process. Crystal growth occurred in the pseudobinary Hg1- x Cd x Te system. ACRT mixing allowed the lower-density, higher- x-value Hg1- x Cd x Te growth nutrient in the upper region of the ampoule to replenish the depleted melt and allowed the growth of constant- x-value, higher-density Hg1- x Cd x Te. The material grown by this research and production growth process yielded single crystals that had improved purity, compositional uniformity, precipitate density, and reproducibility in comparison with solid-state recrystallization and other bulk Hg1- x Cd x Te growth techniques. Radial and longitudinal nonuniformities in x-value for Hg1- x Cd x Te were reduced to DME material had highly desired performance characteristics.

  15. Plasma process for development of a bulk heterojunction optoelectronic device: A highly sensitive UV detector

    Science.gov (United States)

    Sharma, Shyamalima; Pal, Arup R.; Chutia, Joyanti; Bailung, Heremba; Sarma, Neelotpal S.; Dass, Narendra N.; Patil, Dinkar

    2012-08-01

    Deposition of composite thin film of polyaniline/TiO2 (PAni/TiO2) has been carried out by a combined process of magnetron sputtering and plasma polymerization at a pressure of 5 × 10-2 Torr using titanium as a target material for sputtering, aniline as monomer, oxygen as reactive gas and argon as carrier gas/ion source for sputtering. The deposition has been achieved using direct current (dc) discharge power of 35 W for sputtering and radio frequency (rf) power of 8-12 W at substrate bias values in the ranges of -80 to -100 V for polymerization. The composition of the film has been studied using infrared spectroscopy, Raman spectroscopy as well as X-ray photoelectron spectroscopy. The morphology of the film has been characterized with the help of a transmission electron microscopy and atomic force microscopy. The ultraviolet (UV) photo-stability of the composite film has been studied by exposing the film deposited on silicon substrate for different reaction times up to 1 h under UV radiation at wave length range of 280-400 nm with an intensity of 0.4 mW/cm2. An organic/inorganic nanocomposite film based photovoltaic device has been developed. The device has an aluminum/composite/indium tin oxide sandwiched structure that shows strong photoresponse in ultraviolet region and hence the device has potential for application as an UV detector.

  16. Soft x-ray intensity profile measurements of electron cyclotron heated plasmas using semiconductor detector arrays in GAMMA 10 tandem mirror.

    Science.gov (United States)

    Minami, R; Imai, T; Kariya, T; Numakura, T; Eguchi, T; Kawarasaki, R; Nakazawa, K; Kato, T; Sato, F; Nanzai, H; Uehara, M; Endo, Y; Ichimura, M

    2014-11-01

    Temporally and spatially resolved soft x-ray analyses of electron cyclotron heated plasmas are carried out by using semiconductor detector arrays in the GAMMA 10 tandem mirror. The detector array has 16-channel for the measurements of plasma x-ray profiles so as to make x-ray tomographic reconstructions. The characteristics of the detector array make it possible to obtain spatially resolved plasma electron temperatures down to a few tens eV and investigate various magnetohydrodynamic activities. High power electron cyclotron heating experiment for the central-cell region in GAMMA 10 has been started in order to reduce the electron drag by increasing the electron temperature.

  17. Dose-rate effects on the bulk etch-rate of CR-39 track detector exposed to low-LET radiations

    CERN Document Server

    Yamauchi, T; Oda, K; Ikeda, T; Honda, Y; Tagawa, S

    1999-01-01

    The effect of gamma-rays and pulsed electrons has been investigated on the bulk etch rate of CR-39 detector at doses up to 100 kGy under various dose-rate between 0.0044 and 35.0 Gy/s. The bulk etch rate increased exponentially with the dose at every examined dose-rates. It was reveled to be strongly depend on the dose-rate: the bulk etch rate was decreased with increasing dose-rate at the same total dose. A primitive model was proposed to explain the dose-rate effect in which oxygen dissolved was assumed to dominate the damage formation process.

  18. Next Generation Semiconductor-Based Radiation Detectors Using Cadmium Magnesium Telluride

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, Sudhir B [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Kutcher, Susan W [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Palsoz, Witold [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Berding, Martha [SRI International, Menlo Park, CA (United States); Burger, Arnold [Brimrose Technology Corporation, Sparks Glencoe, MD (United States)

    2014-11-17

    The primary objective of Phase I was to perform extensive studies on the purification, crystal growth and annealing procedures of CdMgTe to gain a clear understanding of the basic material properties to enable production of detector material with performance comparable to that of CdZnTe. Brimrose utilized prior experience in the growth and processing of II-VI crystals and produced high purity material and good quality single crystals of CdMgTe. Processing techniques for these crystals including annealing, mechanical and chemical polishing, surface passivation and electrode fabrication were developed. Techniques to characterize pertinent electronic characteristics were developed and gamma ray detectors were fabricated. Feasibility of the development of comprehensive defect modeling in this new class of material was demonstrated by our partner research institute SRI International, to compliment the experimental work. We successfully produced a CdMgTe detector that showed 662 keV gamma response with energy resolution of 3.4% (FWHM) at room temperature, without any additional signal correction. These results are comparable to existing CdZnTe (CZT) technology using the same detector size and testing conditions. We have successfully demonstrated detection of gamma-radiation from various isotopes/sources, using CdMgTe thus clearly proving the feasibility that CdMgTe is an excellent, low-cost alternative to CdZnTe.

  19. SEMICONDUCTOR DEVICES Fabrication and characterization of an AlGaN/PZT detector

    Science.gov (United States)

    Yan, Zhang; Jinglan, Sun; Nili, Wang; Li, Han; Xiangyang, Liu; Xiangyang, Li; Xiangjian, Meng

    2010-12-01

    Design, fabrication and characterization of a novel two-color detector for ultraviolet and infrared applications are reported. The detector has a simple multilayer structure composed of n-Al0.3Ga0.7N/i-GaN/p-GaN/SiO2/LaNiO3/PZT/Pt fabricated on a sapphire substrate. Ultraviolet and infrared properties are measured. For the ultraviolet region, a flat band spectral response is achieved in the 302-363 nm band. The detector displays an unbiased responsivity of 0.064 A/W at 355 nm. The current-voltage curve shows that current at zero bias is -1.57 × 10-12 A. This led to a detectivity of 1.81 × 1011 cm · Hz1/2/W. In the infrared region, the detectivity of the detector is 1.58 × 105 cm · Hz1/2/W at 4 μm.

  20. Performance optimization of a free space optical interconnect system with a metal-semiconductor-metal detector

    Science.gov (United States)

    Al-Ababneh, Nedal; Khader, Ateka

    2011-08-01

    In this paper we study the possibility and the potentiality of using metal semiconductor-metal photodetector (MSM-PD) in three-dimensional parallel free space optical interconnect (FSOI) systems. The signal-to-noise ratio (SNR) and time response are used as performance measures to optimize the geometry of MSM-PD used in FSOI systems. Both SNR and time response are evaluated, analyzed, and their dependence on feature parameters of the MSM-PD, including finger size, spacing, and number of fingers, are considered. Based on the results obtained, we show that the use of MSM-PD in FSOI improves the interconnect speed at a given acceptable SNR.

  1. Micro and nanophotonics for semiconductor infrared detectors towards an ultimate uncooled device

    CERN Document Server

    Jakšic, Zoran

    2014-01-01

    The advent of microelectromechanic system (MEMS) technologies and nanotechnologies has resulted in a multitude of structures and devices with ultra compact dimensions and with vastly enhanced or even completely novel properties. In the field of photonics it resulted in the appearance of new paradigms, including photonic crystals that exhibit photonic bandgap and represent an optical analog of semiconductors and metamaterials that have subwavelength features and may have almost arbitrary values of effective refractive index, including those below zero. In addition to that, a whole new field of

  2. The Si/CdTe semiconductor Compton camera of the ASTRO-H Soft Gamma-ray Detector (SGD)

    CERN Document Server

    Watanabe, Shin; Fukazawa, Yasushi; Ichinohe, Yuto; Takeda, Shin'ichiro; Enoto, Teruaki; Fukuyama, Taro; Furui, Shunya; Genba, Kei; Hagino, Kouichi; Harayama, Astushi; Kuroda, Yoshikatsu; Matsuura, Daisuke; Nakamura, Ryo; Nakazawa, Kazuhiro; Noda, Hirofumi; Odaka, Hirokazu; Ohta, Masayuki; Onishi, Mitsunobu; Saito, Shinya; Sato, Goro; Sato, Tamotsu; Takahashi, Tadayuki; Tanaka, Takaaki; Togo, Atsushi; Tomizuka, Shinji

    2015-01-01

    The Soft Gamma-ray Detector (SGD) is one of the instrument payloads onboard ASTRO-H, and will cover a wide energy band (60--600 keV) at a background level 10 times better than instruments currently in orbit. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield. The Compton camera in the SGD is realized as a hybrid semiconductor detector system which consists of silicon and cadmium telluride (CdTe) sensors. The design of the SGD Compton camera has been finalized and the final prototype, which has the same configuration as the flight model, has been fabricated for performance evaluation. The Compton camera has overall dimensions of 12 cm x 12 cm x 12 cm, consisting of 32 layers of Si pixel sensors and 8 layers of CdTe pixel sensors surrounded by 2 layers of CdTe pixel sensors. The detection efficiency of the Compton camera reaches about 15% and 3% for 100 keV and 511 keV gamma rays, respectively. The pixel pitch of the Si and CdTe sensors is 3.2 mm, and ...

  3. Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications

    Directory of Open Access Journals (Sweden)

    Anna Maria Mancini

    2009-05-01

    Full Text Available Over the last decade, cadmium telluride (CdTe and cadmium zinc telluride (CdZnTe wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si and germanium (Ge, CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector performance and some major applications. Astrophysical and medical applications are discussed, pointing out the ongoing Italian research activities on the development of these detectors.

  4. Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications.

    Science.gov (United States)

    Sordo, Stefano Del; Abbene, Leonardo; Caroli, Ezio; Mancini, Anna Maria; Zappettini, Andrea; Ubertini, Pietro

    2009-01-01

    Over the last decade, cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si) and germanium (Ge), CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector performance and some major applications. Astrophysical and medical applications are discussed, pointing out the ongoing Italian research activities on the development of these detectors.

  5. SU-C-201-03: Coded Aperture Gamma-Ray Imaging Using Pixelated Semiconductor Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, S [Wayne State University, Detroit, MI (United States); Kaye, W; Jaworski, J [H3D, Inc., Ann Arbor, MI (United States); He, Z [University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Purpose: Improved localization of gamma-ray emissions from radiotracers is essential to the progress of nuclear medicine. Polaris is a portable, room-temperature operated gamma-ray imaging spectrometer composed of two 3×3 arrays of thick CdZnTe (CZT) detectors, which detect gammas between 30keV and 3MeV with energy resolution of <1% FWHM at 662keV. Compton imaging is used to map out source distributions in 4-pi space; however, is only effective above 300keV where Compton scatter is dominant. This work extends imaging to photoelectric energies (<300keV) using coded aperture imaging (CAI), which is essential for localization of Tc-99m (140keV). Methods: CAI, similar to the pinhole camera, relies on an attenuating mask, with open/closed elements, placed between the source and position-sensitive detectors. Partial attenuation of the source results in a “shadow” or count distribution that closely matches a portion of the mask pattern. Ideally, each source direction corresponds to a unique count distribution. Using backprojection reconstruction, the source direction is determined within the field of view. The knowledge of 3D position of interaction results in improved image quality. Results: Using a single array of detectors, a coded aperture mask, and multiple Co-57 (122keV) point sources, image reconstruction is performed in real-time, on an event-by-event basis, resulting in images with an angular resolution of ∼6 degrees. Although material nonuniformities contribute to image degradation, the superposition of images from individual detectors results in improved SNR. CAI was integrated with Compton imaging for a seamless transition between energy regimes. Conclusion: For the first time, CAI has been applied to thick, 3D position sensitive CZT detectors. Real-time, combined CAI and Compton imaging is performed using two 3×3 detector arrays, resulting in a source distribution in space. This system has been commercialized by H3D, Inc. and is being acquired for

  6. Fluorocarbon evaporative cooling developments for the ATLAS pixel and semiconductor tracking detectors

    CERN Document Server

    Anderssen, E; Berry, S; Bonneau, P; Bosteels, Michel; Bouvier, P; Cragg, D; English, R; Godlewski, J; Górski, B; Grohmann, S; Hallewell, G D; Hayler, T; Ilie, S; Jones, T; Kadlec, J; Lindsay, S; Miller, W; Niinikoski, T O; Olcese, M; Olszowska, J; Payne, B; Pilling, A; Perrin, E; Sandaker, H; Seytre, J F; Thadome, J; Vacek, V

    1999-01-01

    Heat transfer coefficients 2-5.103 Wm-2K-1 have been measured in a 3.6 mm I.D. heated tube dissipating 100 Watts - close to the full equivalent power (~110 W) of a barrel SCT detector "stave" - over a range of power dissipations and mass flows in the above fluids. Aspects of full-scale evaporative cooling circulator design for the ATLAS experiment are discussed, together with plans for future development.

  7. MCNPX Monte Carlo simulations of particle transport in SiC semiconductor detectors of fast neutrons

    Science.gov (United States)

    Sedlačková, K.; Zat'ko, B.; Šagátová, A.; Pavlovič, M.; Nečas, V.; Stacho, M.

    2014-05-01

    The aim of this paper was to investigate particle transport properties of a fast neutron detector based on silicon carbide. MCNPX (Monte Carlo N-Particle eXtended) code was used in our study because it allows seamless particle transport, thus not only interacting neutrons can be inspected but also secondary particles can be banked for subsequent transport. Modelling of the fast-neutron response of a SiC detector was carried out for fast neutrons produced by 239Pu-Be source with the mean energy of about 4.3 MeV. Using the MCNPX code, the following quantities have been calculated: secondary particle flux densities, reaction rates of elastic/inelastic scattering and other nuclear reactions, distribution of residual ions, deposited energy and energy distribution of pulses. The values of reaction rates calculated for different types of reactions and resulting energy deposition values showed that the incident neutrons transfer part of the carried energy predominantly via elastic scattering on silicon and carbon atoms. Other fast-neutron induced reactions include inelastic scattering and nuclear reactions followed by production of α-particles and protons. Silicon and carbon recoil atoms, α-particles and protons are charged particles which contribute to the detector response. It was demonstrated that although the bare SiC material can register fast neutrons directly, its detection efficiency can be enlarged if it is covered by an appropriate conversion layer. Comparison of the simulation results with experimental data was successfully accomplished.

  8. Optimizing the design and analysis of cryogenic semiconductor dark matter detectors for maximum sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Pyle, Matt Christopher [Stanford Univ., CA (United States)

    2012-01-01

    In this thesis, we illustrate how the complex E- field geometry produced by interdigitated electrodes at alternating voltage biases naturally encodes 3D fiducial volume information into the charge and phonon signals and thus is a natural geometry for our next generation dark matter detectors. Secondly, we will study in depth the physics of import to our devices including transition edge sensor dynamics, quasi- particle dynamics in our Al collection fins, and phonon physics in the crystal itself so that we can both understand the performance of our previous CDMS II device as well as optimize the design of our future devices. Of interest to the broader physics community is the derivation of the ideal athermal phonon detector resolution and it's T3 c scaling behavior which suggests that the athermal phonon detector technology developed by CDMS could also be used to discover coherent neutrino scattering and search for non-standard neutrino interaction and sterile neutrinos. These proposed resolution optimized devices can also be used in searches for exotic MeV-GeV dark matter as well as novel background free searches for 8GeV light WIMPs.

  9. Impurities, Defects and Diffusion in Semiconductors: Bulk and Layered Structures. Materials Research Society Symposium Proceedings. Volume 163

    Science.gov (United States)

    1990-11-21

    Processing and Science, D.B. Poker, C. Ortiz, 1989, ISBN: 1-55899-025-9 Volume 153-Interfaces Between Polymers , Metals, and Ceramics, B.M. DeKoven, A.J...Interfaces in Composite Materials, C.G. Pantano, E.J.H. Chen, 1989, ISBN 1-55899-058-5 Volume 171- Polymer Based Molecular Composites, D.W. Schaefer, J.E...electrical characteristics of a semiconductor such as its free carrier concentration, mobility and minority cartier lifetime are determined by the

  10. Medical Compton cameras based on semiconductor detectors design and experimental development

    CERN Document Server

    Scannavini, M G

    2001-01-01

    The work presented in this thesis is aimed at the study of Compton scatter as an alternative method of collimating gamma-rays in nuclear medicine applications. Conventional approaches to radioisotope medical imaging and their current limitations are examined. The theory of electronic collimation based on Compton scatter is introduced and it is shown that in principle its application could provide an advantageous imaging method, with both high spatial resolution and high sensitivity. The current status of research in the field, of Compton cameras is assessed and potential niches for applications of clinical interest are suggested. The criteria for the design of a Compton scatter camera are examined. A variety of semiconductors are considered for the construction of an electronic collimator and results from Monte Carlo computer simulations are presented for photon energies of clinical interest. It is concluded that the most viable approach is to design a silicon collimator for the imaging of high-energy (511 ke...

  11. Neural-based pile-up correction and ballistic deficit correction of X-ray semiconductor detectors using the Monte Carlo simulation and the Ramo theorem

    Science.gov (United States)

    Kafaee, Mahdi; Moussavi Zarandi, Ali; Taheri, Ali

    2016-03-01

    Pile-up distortion is a common problem in many nuclear radiation detection systems, especially in high count rates. It can be solved by hardware-based pile-up rejections, but there is no complete pile-up elimination in this way. Additionally, the methods can lead to poor quantitative results. Generally, time characteristics of semiconductor detector pulses are different from Scintillator detector pulses due to ballistic deficit. Hence, pulse processing-based pile-up correction in the detectors should consider this specification. In this paper, the artificial neural network pile-up correction method is applied for silicon detector piled-up pulses. For this purpose, the interaction of photons with a silicon detector is simulated by the MCNP4c code and the pulse current is calculated by Ramo's theorem. In this approach, we use a sub-Nyquist frequency sampling. The results show that the proposed method is reliable for pile-up correction and ballistic deficit in semiconductor detectors. The technique is remarkable for commercial considerations and high-speed, real-time calculations.

  12. Sub-cycle control of multi-THz high-harmonic generation and all-coherent charge transport in bulk semiconductors

    Science.gov (United States)

    Lange, C.; Schubert, O.; Hohenleutner, M.; Langer, F.; Baierl, S.; Maag, T.; Urbanek, B.; Edwards, E. R. J.; Woltersdorf, G.; Bougeard, D.; Huttner, U.; Golde, D.; Meier, T.; Kira, M.; Koch, S. W.; Huber, R.

    2015-02-01

    Ultrafast transport of electrons in semiconductors lies at the heart of high-speed electronics, electro-optics and fundamental solid-state physics. Intense phase-locked terahertz (THz) pulses at photon energies far below electronic interband resonances may serve as a precisely adjustable alternating bias, strongly exceeding d.c. breakdown voltages. Here, we exploit the near-field enhancement in gold metamaterial structures on undoped bulk GaAs, driven by few-cycle THz transients centered at 1 THz, to bias the semiconductor substrate with field amplitudes exceeding 12 MV/cm. Such fields correspond to a potential drop of the bandgap energy over a distance of only two unit cells. In this extremely off-resonant scenario characterized by a Keldysh parameter of γK ≈ 0.02, massive interband Zener tunneling injects a sizeable carrier density exceeding 1019 cm-3, and strong photoluminescence results. At a center frequency of 30 THz, THz transients with peak fields of 72 MV/cm analogously excite carriers in a bulk, semiconducting GaSe crystal, without metamaterial. Here, in contrast, we are able to drive coherent interband polarization and furthermore dynamical Bloch oscillations of electrons in the conduction band, on femtosecond time scales. The dynamics entail the generation of absolutely phase-stable high-harmonic transients containing spectral components up to the 22nd order of the fundamental frequency, spanning 12.7 optical octaves throughout the entire terahertz-to-visible domain between 0.1 and 675 THz. Our experiments establish a new field of light-wave electronics exploring coherent charge transport at optical clock rates and bring picosecond-scale electric circuitry at the interface of THz optics and electronics into reach.

  13. A new formulation for surface roughness limited mobility in bulk and ultra-thin-body metal-oxide-semiconductor transistors

    Science.gov (United States)

    Lizzit, Daniel; Esseni, David; Palestri, Pierpaolo; Selmi, Luca

    2014-12-01

    This paper presents a new model for the surface roughness (SR) limited mobility in MOS transistors. The model is suitable for bulk and thin body devices and explicitly takes into account the non linear relation between the displacement Δ of the interface position and the SR scattering matrix elements, which is found to significantly influence the r.m.s value (Δrms) of the interface roughness that is necessary to reproduce SR-limited mobility measurements. In particular, comparison with experimental mobility for bulk Si MOSFETs shows that with the new SR scattering model a good agreement with measured mobility can be obtained with Δrms values of about 0.2 nm, which is in good agreement with several AFM and TEM measurements. For thin body III-V MOSFETs, the proposed model predicts a weaker mobility degradation at small well thicknesses (Tw), compared to the Tw 6 behavior observed in Si extremely thin body devices.

  14. Enhanced infrared magneto-optical response of the nonmagnetic semiconductor BiTeI driven by bulk Rashba splitting

    Energy Technology Data Exchange (ETDEWEB)

    Demko, L.; Tokura, Y. [Multiferroics Project, ERATO, JST, c/o Department of Applied Physics, University of Tokyo (Japan); Schober, G.A.H. [Institute for Theoretical Physics, University of Heidelberg (Germany); Kocsis, V.; Kezsmarki, I. [Department of Physics, Budapest University of Technology and Economics and Condensed Matter Research Group of the Hungarian Academy of Sciences (Hungary); Bahramy, M.S.; Murakawa, H. [CMRG and CERG, RIKEN ASI (Japan); Lee, J.S.; Arita, R.; Nagaosa, N. [Department of Applied Physics, University of Tokyo (Japan)

    2013-07-01

    We study the magneto-optical (MO) response of the polar semiconducting BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being nonmagnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (up to 3 T). Our first-principles calculations show that the enhanced MO response of BiTeI comes mainly from the intraband transitions between the Rashba-split bulk conduction bands. These transitions connecting electronic states with opposite spin directions become active due to the presence of strong spin-orbit interaction and give rise to distinct features in the MO spectra with a systematic doping dependence. We predict an even more pronounced enhancement in the low-energy MO response and dc Hall effect near the crossing (Dirac) point of the conduction bands.

  15. Bulk electrical properties of single-walled carbon nanotubes immobilized by dielectrophoresis: evidence of metallic or semiconductor behavior.

    Science.gov (United States)

    Mureau, Natacha; Watts, Paul C P; Tison, Yann; Silva, S Ravi P

    2008-06-01

    We report the electrical characterization of single-walled carbon nanotubes (SWCNTs) trapped between two electrodes by dielectrophoresis (DEP). At high frequency, SWCNTs collected by DEP are expected to be of metallic type. Indeed current-voltage (I-V) measurements for devices made at 10 MHz show high values of conductivity and exhibit metallic behavior with linear and symmetric electrical features attributed to ohmic conduction. At low frequency, SWCNTs attracted by DEP are expected to be of semiconducting nature. Devices made at 10 kHz behave as semiconductors and demonstrate nonlinear and rectifying electrical characteristics with conductivities many orders of magnitude below the sample resulting from high-frequency immobilization of SWCNTs. Conducting atomic force microscopy (C-AFM) and current density calculation results are presented to reinforce results obtained by I-V measurements which clearly show type separation of SWCNTs after DEP experiments.

  16. Ultrafast nuclear myocardial perfusion imaging on a new gamma camera with semiconductor detector technique: first clinical validation

    Energy Technology Data Exchange (ETDEWEB)

    Buechel, Ronny R.; Herzog, Bernhard A.; Husmann, Lars; Burger, Irene A.; Pazhenkottil, Aju P.; Treyer, Valerie; Valenta, Ines; Schulthess, Patrick von; Nkoulou, Rene; Wyss, Christophe A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology (ZIHP), Zurich (Switzerland)

    2010-04-15

    To assess the diagnostic performance of a novel ultrafast cardiac gamma camera with cadmium-zinc-telluride (CZT) solid-state semiconductor detectors for nuclear myocardial perfusion imaging (MPI). The study group comprised 75 consecutive patients (55 men, BMI range 19-45 kg/m{sup 2}) who underwent a 1-day {sup 99m}Tc-tetrofosmin adenosine-stress/rest imaging protocol. Scanning was performed first on a conventional dual-detector SPECT gamma camera (Ventri, GE Healthcare) with a 15-min acquisition time each for stress and rest. All scans were immediately repeated on an ultrafast CZT camera (Discovery 530 NMc, GE Healthcare) with a 3-min scan time for stress and a 2-min scan time for rest. Clinical agreement (normal, ischaemia, scar) between CZT and SPECT was assessed for each patient and for each coronary territory using SPECT MPI as the reference standard. Segmental myocardial tracer uptake values (percent of maximum) using a 20-segment model and left ventricular ejection fraction (EF) values obtained using CZT were compared with those obtained using conventional SPECT by intraclass correlation and by calculating Bland-Altman limits of agreement. There was excellent clinical agreement between CZT and conventional SPECT on a per-patient basis (96.0%) and on a per-vessel territory basis (96.4%) as shown by a highly significant correlation between segmental tracer uptake values (r=0.901, p<0.001). Similarly, EF values for both scanners were highly correlated (r=0.976, p<0.001) with narrow Bland-Altman limits of agreement (-5.5-10.6%). The novel CZT camera allows a more than fivefold reduction in scan time and provides clinical information equivalent to conventional standard SPECT MPI. (orig.)

  17. Quantum efficiency of a single microwave photon detector based on a semiconductor double quantum dot

    Science.gov (United States)

    Wong, Clement H.; Vavilov, Maxim G.

    2017-01-01

    Motivated by recent interest in implementing circuit quantum electrodynamics with semiconducting quantum dots, we consider a double quantum dot (DQD) capacitively coupled to a superconducting resonator that is driven by the microwave field of a superconducting transmission line. We analyze the DQD current response using input-output theory and show that the resonator-coupled DQD is a sensitive microwave single photon detector. Using currently available experimental parameters of DQD-resonator coupling and dissipation, including the effects of 1 /f charge noise and phonon noise, we determine the parameter regime for which incident photons are completely absorbed and near-unit ≳98 % efficiency can be achieved. We show that this regime can be reached by using very high quality resonators with quality factor Q ≃105 .

  18. First Investigation on a novel 2D position sensitive semiconductor detector concept

    CERN Document Server

    Bassignana, D; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I

    2012-01-01

    This paper presents a first study of the performance of a novel 2D position-sensitive microstrip detector, where the resistive charge division method was implemented by replacing the metallic electrodes with resistive electrodes made of polycrystalline silicon. A characterization of two proof-of-concept prototypes with different values of the electrode resistivity was carried out using a pulsed Near Infra-Red laser. The experimental data were compared with the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The good agreement between experimental and simulation results establishes the soundness of resistive charge division method in silicon microstrip sensors and validates the developed simulation as a tool for the optimization of future sensor prototypes. Spatial resolution in the strip length direction depends on the ionizing event position. The average value obtained from the protype analysis is close to 1.2% of the strip length for a 6 MIP signal.

  19. Measurements on semiconductor and scintillator detectors at the Advanced Light Source (Conference Presentation)

    Science.gov (United States)

    Camarda, Giuseppe S.; Bolotnikov, Aleksey E.; Cui, Yonggang; Gul, Rubi; Hossain, Anwar; Roy, Utpal N.; Yang, Ge; James, Ralph B.; Vanier, Peter E.

    2016-09-01

    During the transition period between closure of Beamline X27B at BNL's NSLS and the opening of Beamline MID at NSLS-II, we began operation of LBNL's ALS Beamline 3.3.2 to carry out our radiation detection materials RD. Measurements performed at this Beamline include, X-ray Detector Response Mapping and White Beam X-ray Diffraction Topography (WBXDT), among others. We will introduce the capabilities of the Beamline and present the most recent results obtained on CdZnTe and scintillators. The goal of the studies on CdZnTe is to understand the origin and effects of subgrain boundaries and help to visualize the presence of a higher concentration of impurities, which might be responsible for the deterioration of the energy resolution and response uniformity in the vicinity of the sub-grain boundaries. The results obtained in the second year of measurements will be presented.

  20. Measurement of effect of electron cyclotron heating in a tandem mirror plasma using a semiconductor detector array and an electrostatic energy analyzer

    Science.gov (United States)

    Minami, R.; Imai, T.; Kariya, T.; Numakura, T.; Uehara, M.; Tsumura, K.; Ebashi, Y.; Kajino, S.; Endo, Y.; Nakashima, Y.

    2016-11-01

    Temporally and spatially resolved soft x-ray and end-loss-electron analyses of the electron cyclotron heated plasmas are carried out by using a semiconductor detector array and an electrostatic energy analyzer in the GAMMA 10 tandem mirror. The flux and the energy spectrum of the end loss electrons are measured by a multi-grid energy analyzer. Recently, the electron cyclotron heating power modulation experiments have been started in order to generate and control the high heat flux and to make the edge localized mode-like intermittent heat load pattern for the divertor simulation studies by the use of these detectors for electron properties.

  1. Cavity perturbation techniques for measurement of the microwave conductivity and dielectric constant of a bulk semiconductor material.

    Science.gov (United States)

    Eldumiati, I. I.; Haddad, G. I.

    1972-01-01

    Cavity perturbation techniques offer a very sensitive and highly versatile means for studying the complex microwave conductivity of a bulk material. A knowledge of the cavity coupling factor in the absence of perturbation, together with the change in the reflected power and the cavity resonance frequency shift, are adequate for the determination of the material properties. This eliminates the need to determine the Q-factor change with perturbation which may lead to appreciable error, especially in the presence of mismatch loss. The measurement accuracy can also be improved by a proper choice of the cavity coupling factor prior to the perturbation.

  2. Determination of bulk diffusion lengths for angle-lapped semiconductor material via the scanning electron microscope: A theoretical analysis

    Science.gov (United States)

    Vonroos, O.

    1978-01-01

    A standard procedure for the determination of the minority carrier diffusion length by means of a scanning electron microscope (SEM) consists in scanning across an angle-lapped surface of a P-N junction and measuring the resultant short circuit current I sub sc as a function of beam position. A detailed analysis of the I sub sc originating from this configuration is presented. It is found that, for a point source excitation, the I sub sc depends very simply on x, the variable distance between the surface and the junction edge. The expression for the I sub sc of a planar junction device is well known. If d, the constant distance between the plane of the surface of the semiconductor and the junction edge in the expression for the I of a planar junction is merely replaced by x, the variable distance of the corresponding angle-lapped junction, an expression results which is correct to within a small fraction of a percent as long as the angle between the surfaces, 2 theta sub 1, is smaller than 10 deg.

  3. High-contrast X-ray micro-tomography of low attenuation samples using large area hybrid semiconductor pixel detector array of 10 × 5 Timepix chips

    Science.gov (United States)

    Karch, J.; Krejci, F.; Bartl, B.; Dudak, J.; Kuba, J.; Kvacek, J.; Zemlicka, J.

    2016-01-01

    State-of-the-art hybrid pixel semiconductor detectors provide excellent imaging properties such as unlimited dynamic range, high spatial resolution, high frame rate and energy sensitivity. Nevertheless, a limitation in the use of these devices for imaging has been the small sensitive area of a few square centimetres. In the field of microtomography we make use of a large area pixel detector assembled from 50 Timepix edgeless chips providing fully sensitive area of 14.3 × 7.15 cm2. We have successfully demonstrated that the enlargement of the sensitive area enables high-quality tomographic measurements of whole objects with high geometrical magnification without any significant degradation in resulting reconstructions related to the chip tilling and edgeless sensor technology properties. The technique of micro-tomography with the newly developed large area detector is applied for samples formed by low attenuation, low contrast materials such a seed from Phacelia tanacetifolia, a charcoalified wood sample and a beeswax seal sample.

  4. Improved performance of GaN metal-semiconductor-metal ultraviolet detectors by depositing SiO2 nanoparticles on a GaN surface

    Science.gov (United States)

    Sun, Xiaojuan; Li, Dabing; Jiang, Hong; Li, Zhiming; Song, Hang; Chen, Yiren; Miao, Guoqing

    2011-03-01

    GaN metal-semiconductor-metal (MSM) ultraviolet detectors were investigated by depositing different density of SiO2 nanoparticles (SNPs) on the GaN. It was shown that the dark current of the detectors with SNPs was more than one order of magnitude lower than that without SNPs and the peak responsivity was enhanced after deposition of the SNPs. Atomic force microscopy observations indicated that the SNPs usually formed at the termination of screw and mixed dislocations, and further current-voltage measurements showed that the leakage of the Schottky contact for the GaN MSM detector decreased with deposited the SNPs. Moreover, the leakage obeyed the Frenkel-Poole emission model, which meant that the mechanism for improving the performance is the SNPs passivation of the dislocations followed by the reduction in the dark current.

  5. Thermoelectrically cooled semiconductor detectors for non-destructive analysis of works of art by means of energy dispersive X-ray fluorescence

    CERN Document Server

    Cesareo, R; Castellano, A

    1999-01-01

    Thermoelectrically cooled semiconductor detectors, such as Si-PIN, Si-drift, Cd sub 1 sub - sub x Zn sub x Te and HgI sub 2 , coupled to miniaturized low-power X-ray tubes, are well suited in portable systems for energy-dispersive X-ray fluorescence (EDXRF), analysis of archaeological samples. The Si-PIN detector is characterized by a thickness of about 300 mu m, an area of about 2x3 mm sup 2 , an energy resolution of about 200-250 eV at 5.9 keV and an entrance window of 25-75 mu m. The Si-drift detector has approximately the same area and thickness, but an energy resolution of 155 eV at 5.9 keV. The efficiency of these detectors is around 100% from 4 to 10 keV, and then decreases versus energy, reaching approx 9% at 30 keV. Coupled to a miniaturized 10 kV, 0.1 mA, Ca-anode or to a miniaturized 30 kV, 0.1 mA, W-anode X-ray tubes, portable systems can be constructed, which are able to analyse K-lines of elements up to about silver, and L-lines of heavy elements. The Cd sub 1 sub - sub x Zn sub x Te detector ha...

  6. A HEMT-Based Cryogenic Charge Amplifier with sub-100 eVee Ionization Resolution for Massive Semiconductor Dark Matter Detectors

    CERN Document Server

    Phipps, A; Sadoulet, B; Serfass, B; Jin, Y

    2016-01-01

    We present the design and noise performance of a fully cryogenic (T=4 K) HEMT-based charge amplifier for readout of massive semiconductor dark matter detectors operating at sub-Kelvin temperatures. The amplifier has been developed to allow direct detection experiments such as CDMS and EDELWEISS to probe WIMP masses below 10 GeV/$c^2$ while retaining electromagnetic background discrimination. The amplifier dissipates only 1 mW of power and has a measured noise performance three times better than traditional JFET-based charge amplifiers. The predicted optimal filter baseline ionization energy resolution using the measured intrinsic amplifier noise performance and typical detector characteristics is $\\sigma_E \\approx 100 \\,\\text{eV}_{ee}$ (33 electrons). We have measured a calibrated baseline energy resolution of $\\sigma_E = 91\\,\\text{eV}_{ee}$ when coupled to a live CDMS II detector. To our knowledge, this is the best resolution achieved on such massive ($\\approx$150 pF capacitance) radiation detectors.

  7. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  8. Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders

    CERN Multimedia

    Gregor, I; Dierlamm, A H; Palomo pinto, F R; Wilson, F F; Sloan, T; Tuboltsev, Y V; Marone, M; Artuso, M; Cindro, V; Bruzzi, M; Bhardwaj, A; Bohm, J; Mikestikova, M; Altenheiner, S; Walz, M; Breindl, M A; Ruzin, A; Marunko, S; Guskov, J; Haerkoenen, J J; Pospisil, S; Fadeyev, V; Makarenko, L; Kaminski, P; Zelazko, J; Pintilie, L; Radu, R; Nistor, S V; Ullan comes, M; Storasta, J V; Gaubas, E; Lacasta llacer, C; Garutti, E; Buhmann, P; Khomenkov, V; Poehlsen, J A; Fernandez garcia, M; Buttar, C; Eklund, L M; Eremin, V; Aleev, A; Modi, B; Gisen, A J; Nikolopoulos, K; Van beuzekom, M G; Kozlowski, R; Lozano fantoba, M; Leroy, C; Pernegger, H; Vila alvarez, I; Lounis, A; Eremin, I; Fadeeva, N; Rogozhkin, S; Shivpuri, R K; Arsenovich, T; Ott, J; Sicho, P; Abt, M; Savic, N; Lopez paz, I; Monaco, V; Visser, J; Lynn, D; Horazdovsky, T; Solar, M; Dervan, P J; Meng, L; Spencer, E N; Kazuchits, N; Brzozowski, A; Kozubal, M; Nistor, L C; Marti i garcia, S; Fretwurst, E; Hoenniger, F; Schwandt, J; Hartmann, F; Maneuski, D; Holmkvist, W; Gadda, A; Preiss, J; Macchiolo, A; Nisius, R; Grinstein, S; Marchiori, G; Gonella, L; Slavicek, T; Masek, P; Casse, G; Flores, D; Tuuva, T; Charron, S; Rubinskiy, I; Jansen, H; Eichhorn, T V; Matysek, M; Andersson-lindstroem, G; Donegani, E; Oshea, V; Muenstermann, D; Verbitskaya, E; Mitina, D; Grigoriev, E; Zaluzhnyy, A; Mikuz, M; Kramberger, G; Scaringella, M; Ranjeet, R; Jain, A; Luukka, P R; Tuominen, E M; Goessling, C; Klingenberg, R; Lange, J C; Bomben, M; Allport, P P; Cartiglia, N; Brigljevic, V; Kohout, Z; Quirion, D; Lauer, K; Collins, P; Gallrapp, C; Rohe, T V; Fox, H; Nikitin, A; Spiegel, L G; Creanza, D M; Menichelli, D; Mcduff, H; Carna, M; Weigell, P; Chauveau, J; Bortoletto, D; Staiano, A; Bellan, R; Szumlak, T; Sopko, V; Pawlowski, M; Pintilie, I; Pellegrini, G; Rafi tatjer, J M; Golovleva, M; Moll, M; Eckstein, D; Klanner, R; Gomez, G; Shepelev, A; Golubev, A; Lipton, R J; Borgia, A; Zavrtanik, M; Manna, N; Ranjan, K; Chhabra, S; Beyer, J; Korolkov, I; Heintz, U; Sadrozinski, H; Seiden, A; Surma, B; Esteban, S; Kazukauskas, V; Kalendra, V; Mekys, A; Tackmann, K; Steinbrueck, G; Pohlsen, T; Bolla, G; Mandic, I; Zontar, D; Focardi, E; Seidel, S C; Winkler, A D; Wunstorf, R; Parzefall, U; Moser, H; Calderini, G; Briglin, D L; Sopko, B; Buckland, M D; Vaitkus, J V; Ortlepp, T

    2002-01-01

    The requirements at the Large Hadron Collider (LHC) at CERN have pushed the present day silicon tracking detectors to the very edge of the current technology. Future very high luminosity colliders or a possible upgrade scenario of the LHC to a luminosity of 10$^{35}$ cm$^{-2}$s$^{-1}$ will require semiconductor detectors with substantially improved properties. Considering the expected total fluences of fast hadrons above 10$^{16}$ cm$^{-2}$ and a possible reduced bunch-crossing interval of $\\approx$10 ns, the detector must be ultra radiation hard, provide a fast and efficient charge collection and be as thin as possible.\\\\ We propose a research and development program to provide a detector technology, which is able to operate safely and efficiently in such an environment. Within this project we will optimize existing methods and evaluate new ways to engineer the silicon bulk material, the detector structure and the detector operational conditions. Furthermore, possibilities to use semiconductor materials othe...

  9. Purification and preparation of bismuth(III) iodide for application as radiation semiconductor detector; Purificacao e preparacao do cristal semicondutor de iodeto de bismuto para aplicacao como detector de radiacao

    Energy Technology Data Exchange (ETDEWEB)

    Ferraz, Caue de Mello

    2016-11-01

    This study describes the experimental procedure of a BiI{sub 3} purification method powder, aiming a future application of these semiconductor crystals as room temperature radiation detector. The Repeated Vertical Bridgman Technique was applied for the purification, based on the melting and nucleation phenomena. An ampoule filled with a maximum of 25% by volume of BiI{sub 3} powder was mounted into the Bridgman furnace and vertically moved at a speed of 2 millimeters per hour, inside the furnace with programmed thermal gradient and temperature profile, at a temperature maximum of 530 deg C. The reduction of the impurities in the BiI{sub 3}, each purification, was analysed by Instrumental Neutron Activation Analysis (INAA), in order to evaluate the efficiency of the purification technique established in this work, for trace metal impurities. It was demonstrated that the Repeated Bridgman is effective to reduce the concentration of many impurities in BiI{sub 3}, such as Ag, As, Br, Cr, K, Mo, Na and Sb. The crystalline structure of the BiI{sub 3} crystal purified twice and third times was similar to the BiI{sub 3} pattern. However, for BiI{sub 3} powder and purified once an intensity contribution of the BiOI was observed in the diffractograms. It is known that semiconductor detectors fabricated from high purity crystal exhibit significant improvement in their performance compared to those produced from low purity crystals. (author)

  10. Semiconductor sensors

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Frank, E-mail: frank.hartmann@cern.c [Institut fuer Experimentelle Kernphysik, KIT, Wolfgang-Gaede-Str. 1, Karlsruhe 76131 (Germany)

    2011-02-01

    Semiconductor sensors have been around since the 1950s and today, every high energy physics experiment has one in its repertoire. In Lepton as well as Hadron colliders, silicon vertex and tracking detectors led to the most amazing physics and will continue doing so in the future. This contribution tries to depict the history of these devices exemplarily without being able to honor all important developments and installations. The current understanding of radiation damage mechanisms and recent R and D topics demonstrating the future challenges and possible technical solutions for the SLHC detectors are presented. Consequently semiconductor sensor candidates for an LHC upgrade and a future linear collider are also briefly introduced. The work presented here is a collage of the work of many individual silicon experts spread over several collaborations across the world.

  11. Biggest semiconductor installed

    CERN Multimedia

    2008-01-01

    Scientists and technicians at the European Laboratory for Particle Physics, commonly known by its French acronym CERN (Centre Europen pour la Recherche Nuclaire), have completed the installation of the largest semiconductor silicon detector.

  12. Possible application of scintillation detectors with semiconductor PMT for cosmic-neutron and gamma-ray detection

    Science.gov (United States)

    Mokrousov, M. I.; Vostrukhin, A. A.; Karpushkina, N. E.; Malakhov, A. V.

    2016-09-01

    Solar system planets exploration and cosmic neutrons and gamma-ray flux research have been dynamically evolving for several decades. Different scintillation crystals are used for this purpose along with photo signal receivers, such as vacuum photomultiplier tubes (PMT). Many studies are being performed in order to provide alternative devices for photon signal capture: PIN-diodes,avalanche photodiodes, semiconductor silicon photomultipliers. We study the applicability of a silicon PMT in employing highresolution crystals in space applications.

  13. Radiation effects in semiconductors

    CERN Document Server

    2011-01-01

    There is a need to understand and combat potential radiation damage problems in semiconductor devices and circuits. Written by international experts, this book explains the effects of radiation on semiconductor devices, radiation detectors, and electronic devices and components. These contributors explore emerging applications, detector technologies, circuit design techniques, new materials, and innovative system approaches. The text focuses on how the technology is being used rather than the mathematical foundations behind it. It covers CMOS radiation-tolerant circuit implementations, CMOS pr

  14. Semiconductor radiation detection systems

    CERN Document Server

    2010-01-01

    Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

  15. Noise studies of n-strip on n-bulk silicon microstrip detectors using fast binary readout electronics after irradiation to 3x10 sup 1 sup 4 p cm sup - sup 2

    CERN Document Server

    Robinson, D; Bizzell, J; Buttar, C; Carter, A A; Carter, J R; Goodrick, M; Greenall, A; Hill, J C; Morgan, D; Munday, D J; Ohsugi, T; Phillips, P W; Riedler, P; Smith, N A; Terada, S; Turner, P R; Unno, Y

    1999-01-01

    N-strip on n-bulk silicon microstrip detectors were irradiated at the CERN PS to 3x10 sup 1 sup 4 p cm sup - sup 2 and their post-irradiation performance evaluated using fast binary readout electronics. Strip noise measurements demonstrate that detectors using conventional p-stop strip isolation are vulnerable to microdischarge at high bias voltages after irradiation. However, a novel isolation technique is shown to suppress microdischarge and lead to excellent post-irradiation characteristics.

  16. DEVELOPMENT AND VALIDATION OF CHROMATOGRAPHIC DETERMINATION OF CARVEDILOL PHOSPHATE IN BULK AND PHARMACEUTICAL DOSAGE FORM USING FLUORESCENCE DETECTOR

    Directory of Open Access Journals (Sweden)

    Bhavna A. Patel*, S. J. Parmar , Jigar B. Patel , Gautam R. Chauhan and Aanandi D. Captain

    2012-11-01

    Full Text Available An accurate, sensitive and precise RP-HPLC –Fluorescence method has been developed and validated for the estimation of Carvedilol Phosphate (CP from bulk drug and Pharmaceutical Dosage form. The separation was achieved by a Brownlee analytical C18 column (250mm X 4.6mm, 5μm in isocratic mode, with mobile phase comprises of Acetonitrile : Methanol : Buffer in proportion of 70:20:10v/v/v, buffer was 5mM Potassium Di-hydrogen Phosphate (pH 3.5 adjusted with Ortho Phosphoric Acid. The flow rate of mobile phase was 1.0ml/min and employing fluorescence detection with 280nm excitation and 340nm emission wavelengths. The retention time of Carvedilol Phosphate was 2.20 min.The calibration curve was found to be linear within the concentration range of 10ng/ml to 60ng/ml. The regression data for calibration curve shows good linear relationship with r2 = 0.990. The method was validated in accordance with the requirements of ICH guidelines. Moreover, the proposed analytical method was applied to monitor the formulation commercially available.

  17. Hard-X and gamma-ray imaging detector for astrophysics based on pixelated CdTe semiconductors

    Science.gov (United States)

    Gálvez, J.-L.; Hernanz, M.; Álvarez, L.; Artigues, B.; Ullán, M.; Lozano, M.; Pellegrini, G.; Cabruja, E.; Martínez, R.; Chmeissani, M.; Puigdengoles, C.

    2016-01-01

    Stellar explosions are astrophysical phenomena of great importance and interest. Instruments with high sensitivities are essential to perform detailed studies of cosmic explosions and cosmic accelerators. In order to achieve the needed performance, a hard-X and gamma-ray imaging detector with mm spatial resolution and large enough efficiency is required. We present a detector module which consists of a single CdTe crystal of 12.5 × 12.5mm 2 and 2mm thick with a planar cathode and with the anode segmented in an 11x11 pixel array with a pixel pitch of 1 mm attached to the readout chip. Two possible detector module configurations are considered: the so-called Planar Transverse Field (PTF) and the Parallel Planar Field (PPF). The combination of several modules in PTF or PPF configuration will achieve the desired performance of the imaging detector. The sum energy resolution of all pixels of the CdTe module measured at 122 keV and 356 keV is 3.8% and 2% respectively, in the following operating conditions: PPF irradiation, bias voltage -500 V and temperature -10̂ C.

  18. Nanoimprinted Hybrid Metal-Semiconductor Plasmonic Multilayers with Controlled Surface Nano Architecture for Applications in NIR Detectors

    Directory of Open Access Journals (Sweden)

    Akram A. Khosroabadi

    2015-08-01

    Full Text Available We present a proof of concept for tunable plasmon resonance frequencies in a core shell nano-architectured hybrid metal-semiconductor multilayer structure, with Ag as the active shell and ITO as the dielectric modulation media. Our method relies on the collective change in the dielectric function within the metal semiconductor interface to control the surface. Here we report fabrication and optical spectroscopy studies of large-area, nanostructured, hybrid silver and indium tin oxide (ITO structures, with feature sizes below 100 nm and a controlled surface architecture. The optical and electrical properties of these core shell electrodes, including the surface plasmon frequency, can be tuned by suitably changing the order and thickness of the dielectric layers. By varying the dimensions of the nanopillars, the surface plasmon wavelength of the nanopillar Ag can be tuned from 650 to 690 nm. Adding layers of ITO to the structure further shifts the resonance wavelength toward the IR region and, depending on the sequence and thickness of the layers within the structure, we show that such structures can be applied in sensing devices including enhancing silicon as a photodetection material.

  19. Fluorescence-suppressed time-resolved Raman spectroscopy of pharmaceuticals using complementary metal-oxide semiconductor (CMOS) single-photon avalanche diode (SPAD) detector.

    Science.gov (United States)

    Rojalin, Tatu; Kurki, Lauri; Laaksonen, Timo; Viitala, Tapani; Kostamovaara, Juha; Gordon, Keith C; Galvis, Leonardo; Wachsmann-Hogiu, Sebastian; Strachan, Clare J; Yliperttula, Marjo

    2016-01-01

    In this work, we utilize a short-wavelength, 532-nm picosecond pulsed laser coupled with a time-gated complementary metal-oxide semiconductor (CMOS) single-photon avalanche diode (SPAD) detector to acquire Raman spectra of several drugs of interest. With this approach, we are able to reveal previously unseen Raman features and suppress the fluorescence background of these drugs. Compared to traditional Raman setups, the present time-resolved technique has two major improvements. First, it is possible to overcome the strong fluorescence background that usually interferes with the much weaker Raman spectra. Second, using the high photon energy excitation light source, we are able to generate a stronger Raman signal compared to traditional instruments. In addition, observations in the time domain can be performed, thus enabling new capabilities in the field of Raman and fluorescence spectroscopy. With this system, we demonstrate for the first time the possibility of recording fluorescence-suppressed Raman spectra of solid, amorphous and crystalline, and non-photoluminescent and photoluminescent drugs such as caffeine, ranitidine hydrochloride, and indomethacin (amorphous and crystalline forms). The raw data acquired by utilizing only the picosecond pulsed laser and a CMOS SPAD detector could be used for identifying the compounds directly without any data processing. Moreover, to validate the accuracy of this time-resolved technique, we present density functional theory (DFT) calculations for a widely used gastric acid inhibitor, ranitidine hydrochloride. The obtained time-resolved Raman peaks were identified based on the calculations and existing literature. Raman spectra using non-time-resolved setups with continuous-wave 785- and 532-nm excitation lasers were used as reference data. Overall, this demonstration of time-resolved Raman and fluorescence measurements with a CMOS SPAD detector shows promise in diverse areas, including fundamental chemical research, the

  20. In vivo dosimetry with semiconductor and thermoluminescent detectors applied to head and neck cancer treatment; Dosimetria in vivo com uso de detectores semicondutores e termoluminescentes aplicada ao tratamento de cancer de cabeca e pescoco

    Energy Technology Data Exchange (ETDEWEB)

    Viegas, Claudio Castelo Branco

    2003-03-15

    In vivo dosimetry in radiotherapy, i. e, the assessment of the doses received by patients during their treatments, permits a verification of the therapy quality. A routine of in vivo dosimetry is, undoubtedly, a direct benefit for the patient. Unfortunately, in Brazil and in Latin America this procedure is still a privilege for only a few patients. This routine is of common application only in developed countries. The aim of this work is to show the viability and implementation of a routine in vivo dosimetry, using diodes semiconductors and thermoluminescent dosimeters (TLD), at the radiotherapy section of the National Institute of Cancer in Brazil, in the case of head and neck cancer treatment. In order to reach that aim, the characteristics of the response of diodes ISORAD-p and LiF:Mg;Ti (TLD-100) thermoluminescent detectors in powder form were determined. The performance of those detectors for in vivo dosimetry was tested using an RANDO Alderson anthropomorfic phantom and, once their adequacy proved for the kind of measurements proposed, they were used for dose assessment in the case of tumour treatments in the head and neck regions, for Cobalt-60 irradiations. (author)

  1. Wide Band-Gap Semiconductor Radiation Detectors: Science Fiction, Horror Story, or Headlines (460th Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    James, Ralph (BNL Nonproliferation and National Security Department)

    2010-08-18

    With radiation constantly occurring from natural sources all around us -- from food, building materials, and rays from the sun, to name a few -- detecting radiotracers for medical procedures and other radiation to keep people safe is not easy. In order to make better use of radiation to diagnose or treat certain health conditions, or to track radiological materials being transported, stored, and used, the quest is on to develop improved radiation detectors. James gives a brief introduction on radiation detection and explain how it is used in applications ranging from medical to homeland security. He then discusses how new materials and better ways to analyze them here at the National Synchrotron Light Source (NSLS) and the future NSLS-II will lead to a new class of radiation detectors that will provide unprecedented advances in medical and industrial imaging, basic science, and the nonproliferation of nuclear materials.

  2. SEMICONDUCTOR DEVICES Parallel readout of two-element CdZnTe detectors with real-time digital signal processing

    Science.gov (United States)

    Zhubin, Shi; Linjun, Wang; Kaifeng, Qin; Jiahua, Min; Jijun, Zhang; Xiaoyan, Liang; Jian, Huang; Ke, Tang; Yiben, Xia

    2010-12-01

    Readout electronics, especially digital electronics, for two-element CdZnTe (CZT) detectors in parallel are developed. The preliminary results show the detection efficiency of the two-element CZT detectors in parallel with analog electronics is as many as 1.8 and 2.1 times the single ones, and the energy resolution (FWHM) is limited by that of the single one by the means of analog electronics. However, the digital method for signal processing will be sufficiently better by contrast with an analog method especially in energy resolution. The energy resolution by the means of digital electronics can be improved by about 26.67%, compared to that only with analog electronics, while their detection efficiency is almost the same. The cause for this difference is also discussed.

  3. Thermoelectrically cooled semiconductor detectors for non-destructive analysis of works of art by means of energy dispersive X-ray fluorescence

    Science.gov (United States)

    Cesareo, Roberto; Ettore Gigante, Giovanni; Castellano, Alfredo

    1999-06-01

    Thermoelectrically cooled semiconductor detectors, such as Si-PIN, Si-drift, Cd1-xZnxTe and HgI 2, coupled to miniaturized low-power X-ray tubes, are well suited in portable systems for energy-dispersive X-ray fluorescence (EDXRF), analysis of archaeological samples. The Si-PIN detector is characterized by a thickness of about 300 μm, an area of about 2×3 mm 2, an energy resolution of about 200-250 eV at 5.9 keV and an entrance window of 25-75 μm. The Si-drift detector has approximately the same area and thickness, but an energy resolution of 155 eV at 5.9 keV. The efficiency of these detectors is around 100% from 4 to 10 keV, and then decreases versus energy, reaching ˜9% at 30 keV. Coupled to a miniaturized 10 kV, 0.1 mA, Ca-anode or to a miniaturized 30 kV, 0.1 mA, W-anode X-ray tubes, portable systems can be constructed, which are able to analyse K-lines of elements up to about silver, and L-lines of heavy elements. The Cd 1- xZn xTe detector has an area of 4 mm 2 and a thickness of 3 mm. It has an energy resolution of about 300 eV at 5.9 keV, and an efficiency of 100% over the whole range of X-rays. Finally the HgI 2 detector has an efficiency of about 100% in the whole range of X-rays, and an energy resolution of about 200 eV at 5.9 keV. Coupled to a small 50-60 kV, 1 mA, W-anode X-ray tube, portable systems can be constructed, for the analysis of practically all elements. These systems were applied to analysis in the field of archaeometry and in all applications for which portable systems are needed or at least useful (for example X-ray transmission measurements, X-ray microtomography and so on). Results of in-field use of these detectors and a comparison among these room temperature detectors in relation to concrete applications are presented. More specifically, concerning EDXRF analysis, ancient gold samples were analysed in Rome, in Mexico City and in Milan, ancient bronzes in Sassari, in Bologna, in Chieti and in Naples, and sulfur (due to pollution

  4. Thermoelectrically cooled semiconductor detectors for non-destructive analysis of works of art by means of energy dispersive X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Cesareo, Roberto; Ettore Gigante, Giovanni; Castellano, Alfredo

    1999-06-01

    Thermoelectrically cooled semiconductor detectors, such as Si-PIN, Si-drift, Cd{sub 1-x}Zn{sub x}Te and HgI{sub 2}, coupled to miniaturized low-power X-ray tubes, are well suited in portable systems for energy-dispersive X-ray fluorescence (EDXRF), analysis of archaeological samples. The Si-PIN detector is characterized by a thickness of about 300 {mu}m, an area of about 2x3 mm{sup 2}, an energy resolution of about 200-250 eV at 5.9 keV and an entrance window of 25-75 {mu}m. The Si-drift detector has approximately the same area and thickness, but an energy resolution of 155 eV at 5.9 keV. The efficiency of these detectors is around 100% from 4 to 10 keV, and then decreases versus energy, reaching {approx}9% at 30 keV. Coupled to a miniaturized 10 kV, 0.1 mA, Ca-anode or to a miniaturized 30 kV, 0.1 mA, W-anode X-ray tubes, portable systems can be constructed, which are able to analyse K-lines of elements up to about silver, and L-lines of heavy elements. The Cd{sub 1-x}Zn{sub x}Te detector has an area of 4 mm{sup 2} and a thickness of 3 mm. It has an energy resolution of about 300 eV at 5.9 keV, and an efficiency of 100% over the whole range of X-rays. Finally the HgI{sub 2} detector has an efficiency of about 100% in the whole range of X-rays, and an energy resolution of about 200 eV at 5.9 keV. Coupled to a small 50-60 kV, 1 mA, W-anode X-ray tube, portable systems can be constructed, for the analysis of practically all elements. These systems were applied to analysis in the field of archaeometry and in all applications for which portable systems are needed or at least useful (for example X-ray transmission measurements, X-ray microtomography and so on). Results of in-field use of these detectors and a comparison among these room temperature detectors in relation to concrete applications are presented. More specifically, concerning EDXRF analysis, ancient gold samples were analysed in Rome, in Mexico City and in Milan, ancient bronzes in Sassari, in Bologna, in

  5. A metal-semiconductor-metal detector based on ZnO nanowires grown on a graphene layer.

    Science.gov (United States)

    Xu, Qiang; Cheng, Qijin; Zhong, Jinxiang; Cai, Weiwei; Zhang, Zifeng; Wu, Zhengyun; Zhang, Fengyan

    2014-02-07

    High quality ZnO nanowires (NWs) were grown on a graphene layer by a hydrothermal method. The ZnO NWs revealed higher uniform surface morphology and better structural properties than ZnO NWs grown on SiO2/Si substrate. A low dark current metal-semiconductor-metal photodetector based on ZnO NWs with Au Schottky contact has also been fabricated. The photodetector displays a low dark current of 1.53 nA at 1 V bias and a large UV-to-visible rejection ratio (up to four orders), which are significantly improved compared to conventional ZnO NW photodetectors. The improvement in UV detection performance is attributed to the existence of a surface plasmon at the interface of the ZnO and the graphene.

  6. The effect of metal-semiconductor contact on the transient photovoltaic characteristic of HgCdTe PV detector.

    Science.gov (United States)

    Cui, Haoyang; Xu, Yongpeng; Yang, Junjie; Tang, Naiyun; Tang, Zhong

    2013-01-01

    The transient photovoltaic (PV) characteristic of HgCdTe PV array is studied using an ultrafast laser. The photoresponse shows an apparent negative valley first, then it evolves into a positive peak. By employing a combined theoretical model of pn junction and Schottky potential, this photo-response polarity changing curves can be interpreted well. An obvious decreasing of ratio of negative valley to positive peak can be realized by limiting the illumination area of the array electrode. This shows that the photoelectric effect of Schottky barrier at metal-semiconductor (M/S) interface is suppressed, which will verify the correctness of the model. The characteristic parameters of transient photo-response induced from p-n junction and Schottky potential are extracted by fitting the response curve utilizing this model. It shows that the negative PV response induced by the Schottky barrier decreases the positive photovoltage generated by the pn junction.

  7. A metal-semiconductor-metal detector based on ZnO nanowires grown on a graphene layer

    Science.gov (United States)

    Xu, Qiang; Cheng, Qijin; Zhong, Jinxiang; Cai, Weiwei; Zhang, Zifeng; Wu, Zhengyun; Zhang, Fengyan

    2014-02-01

    High quality ZnO nanowires (NWs) were grown on a graphene layer by a hydrothermal method. The ZnO NWs revealed higher uniform surface morphology and better structural properties than ZnO NWs grown on SiO2/Si substrate. A low dark current metal-semiconductor-metal photodetector based on ZnO NWs with Au Schottky contact has also been fabricated. The photodetector displays a low dark current of 1.53 nA at 1 V bias and a large UV-to-visible rejection ratio (up to four orders), which are significantly improved compared to conventional ZnO NW photodetectors. The improvement in UV detection performance is attributed to the existence of a surface plasmon at the interface of the ZnO and the graphene.

  8. The Effect of Metal-Semiconductor Contact on the Transient Photovoltaic Characteristic of HgCdTe PV Detector

    Directory of Open Access Journals (Sweden)

    Haoyang Cui

    2013-01-01

    Full Text Available The transient photovoltaic (PV characteristic of HgCdTe PV array is studied using an ultrafast laser. The photoresponse shows an apparent negative valley first, then it evolves into a positive peak. By employing a combined theoretical model of pn junction and Schottky potential, this photo-response polarity changing curves can be interpreted well. An obvious decreasing of ratio of negative valley to positive peak can be realized by limiting the illumination area of the array electrode. This shows that the photoelectric effect of Schottky barrier at metal-semiconductor (M/S interface is suppressed, which will verify the correctness of the model. The characteristic parameters of transient photo-response induced from p-n junction and Schottky potential are extracted by fitting the response curve utilizing this model. It shows that the negative PV response induced by the Schottky barrier decreases the positive photovoltage generated by the pn junction.

  9. Liquid chromatographic method for the simultaneous determination of captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulation, and human serum by programming the detector.

    Science.gov (United States)

    Sultana, Najma; Arayne, M Saeed; Ali, Saeeda Nadir

    2013-10-01

    A highly sensitive LC method with UV detection has been developed for the simultaneous determination of coadministered drugs captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulations, and human serum at the isosbestic point (235 nm) and at individual λmax (220, 255, and 238 nm, respectively) by programming the detector with time to match the individual analyte's chromophore, which enhanced the sensitivity with linear range. The assay involved an isocratic elution of analytes on a Bondapak C18 (10 μm, 25 × 0.46 cm) column at ambient temperature using a mobile phase of methanol/water 80:20 at pH 2.9 and a flow rate of 1.0 mL/min. Linearity was found to be 0.25-25, 0.10-6.0, and 0.20-13.0 μg/mL with correlation coefficient >0.998 and detection limits of 7.39, 3.90, and 9.38 ng/mL, respectively, whereas calibration curves for wavelength-programmed analysis were 0.10-6.0, 0.04-2.56, and 0.10-10.0 μg/mL with correlation coefficient >0.998 and detection limits of 5.79, 2.68, and 3.87 ng/mL, respectively. All the validated parameters were in the acceptable range. The recovery of drugs was 99.32-100.39 and 98.65-101.96% in pharmaceutical formulation and human serum, respectively, at the isosbestic point and at individual λmax . This method is applicable for the analysis of drugs in bulk drug, tablets, serum, and in clinical samples without interference of excipients or endogenous serum components.

  10. Influence of phonons on semiconductor quantum emission

    Energy Technology Data Exchange (ETDEWEB)

    Feldtmann, Thomas

    2009-07-06

    A microscopic theory of interacting charge carriers, lattice vibrations, and light modes in semiconductor systems is presented. The theory is applied to study quantum dots and phonon-assisted luminescence in bulk semiconductors and heterostructures. (orig.)

  11. Growth and characterization of rutile TiO2 nanorods on various substrates with fabricated fast-response metal-semiconductor-metal UV detector based on Si substrate

    Science.gov (United States)

    Selman, Abbas M.; Hassan, Z.

    2015-07-01

    Rutile-phase titanium dioxide nanorods (NRs) were synthesized successfully on p-type silicon (Si) (1 1 1), c-plane sapphire (Al2O3), glass coated with fluorine-doped tin oxide (FTO), glass, and quartz substrates via chemical bath deposition method. All substrates were seeded with a TiO2 seed layer synthesized with a radio frequency reactive magnetron sputtering system prior to NRs growth. The effect of substrate type on structural, morphological, and optical properties of rutile TiO2 NRs was studied. X-ray diffraction, Raman spectroscopy, and field-emission scanning electron microscopy analyses showed the tetragonal rutile structure of the synthesized TiO2 NRs. Optical properties were examined with photoluminescence (PL) spectroscopy of the grown rutile NRs on all substrates, with the spectra exhibiting one strong ultraviolet emission peak intensity compared with broad visible peak. The optimal sample of rutile NRs was grown on Si substrate. Thus, a fast-response metal-semiconductor-metal ultraviolet (UV) detector was fabricated. Upon exposure to 365 nm light (2.3 mW/cm2) at 5 V bias, the device displays 2.62 × 10-5 A photocurrent, and the response and recovery times are calculated as 18.5 and 19.1 ms, respectively. These results demonstrate that the fabricated high-quality photodiode is a promising candidate as a low-cost UV photodetector for commercially integrated photoelectronic applications.

  12. Measurement of gamma-ray intensities of sup 2 sup 3 sup 1 Th using semiconductor detectors

    CERN Document Server

    Chatani, H

    1999-01-01

    Nuclide sup 2 sup 3 sup 1 Th was yielded by the sup 2 sup 3 sup 2 Th(n, 2n) reaction with neutron irradiation in the Kyoto University Reactor (KUR). Moreover, the thorium was purified chemically. Gamma-ray spectra of thorium have been measured using low-energy photon spectrometers and a high-purity germanium detector. Relative gamma-ray intensities ranging from 25 to 352 keV in the decay of sup 2 sup 3 sup 1 Th have been determined with satisfactory accuracy. The results are in very good agreement with those of earlier studies. We observe two new gamma-rays at 77.69 and 177.66 keV, whose intensities are found to be (0.063+-0.010)% and (0.00095+-0.00020)%, respectively, relative to that of 84.21 keV taken as 100%. Absolute intensity of 84.21 keV gamma-ray which is the most prominent one from the decay of sup 2 sup 3 sup 1 Th and that of 185.739 keV following the decay of sup 2 sup 3 sup 5 U are also determined from the secular equilibrium for sup 2 sup 3 sup 5 U- sup 2 sup 3 sup 1 Th. The results obtained in t...

  13. An upgraded drift–diffusion model for evaluating the carrier lifetimes in radiation-damaged semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Lopez, J., E-mail: fjgl@us.es [Dept of Atomic, Molecular and Nuclear Physics, University of Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla (Spain); CNA (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, 41092 Sevilla (Spain); Jimenez-Ramos, M.C.; Rodriguez-Ramos, M. [CNA (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, 41092 Sevilla (Spain); Forneris, J. [Physics Dept./NIS Centre, University of Torino, INFN-Sez. di Torino, via P. Giuria 1, 10125 Torino (Italy); Ceballos, J. [Institute of Microelectronics of Seville, IMSE-CNM (CSIC/University of Seville), Seville 41092 (Spain)

    2016-03-15

    The transport properties of a series of n- and p-type Si diodes have been studied by the ion beam induced charge (IBIC) technique using a 4 MeV proton microbeam. The samples were irradiated with 17 MeV protons at fluences ranging from 1 × 10{sup 12} to 1 × 10{sup 13} p/cm{sup 2} in order to produce a uniform profile of defects with depth. The analysis of the charge collection efficiency (CCE) as a function of the reverse bias voltage has been carried out using an upgraded drift–diffusion (D–D) model which takes into account the possibility of carrier recombination not only in the neutral substrate, as the simple D–D model assumes, but also within the depletion region. This new approach for calculating the CCE is fundamental when the drift length of carriers cannot be considered as much greater that the thickness of the detector due to the ion induced damage. From our simulations, we have obtained the values of the carrier lifetimes for the pristine and irradiated diodes, which have allowed us to calculate the effective trapping cross sections using the one dimension Shockley–Read–Hall model. The results of our calculations have been compared to the data obtained using a recently developed Monte Carlo code for the simulation of IBIC analysis, based on the probabilistic interpretation of the excess carrier continuity equations.

  14. Properties of II-VI Semiconductors: Bulk Crystals, Epitaxial Films, Quantum Well Structures, and Dilute Magnetic Systems. Materials Research Society Symposium Proceedings. Volume 161

    Science.gov (United States)

    1990-11-21

    BULK CdTe P.M. AMIRTHARAJ AND N.K. DHAR U.S. Army Center for Night Vision and Electro-Optics Fort Belvoir, VA-22060 ABSTRACT The native defects...those that contain exposed surfaces. ACKNOWLEDGEMENT The authors wish to acknowledge Mr. Philip R. Boyd of the U.S. Army Center for Night Vision and...del IPN. Apdo. Postal 14-740, 07000 Mexico, D. F. +Departamento de Fisica del Instituto de Ciencias, Universidad Aut6noma de Puebla , Apdo. Postal J-48

  15. The effect of bulk traps on the InP (Indium Phosphide) accumulation type MISFET (Metal-Insulator-Semiconductor Field-Effect Transistor)

    Science.gov (United States)

    Meiners, L. G.

    The enclosed reports represent work performed at USCD on Contract N00014-82-K-2032 entitled Surface and Interfacial Properties of InP and provides a full account of the results obtained during the contract period: May 1, 1984 through April 31, 1985. The paper, Space charge-limited currents and trapping in semi-insulating InP, has now been published in Electron. Device Letters, volume EDL-6, page 356 (1985). The manuscript, Effect of bulk traps on the InP accumulation type MISFET, will be presented as an invited talk at the fall meeting in the Journal of the Electrochemical Society.

  16. Bulk Heterojunction Solar Cells Based on Blends of Conjugated Polymers with II–VI and IV–VI Inorganic Semiconductor Quantum Dots

    Directory of Open Access Journals (Sweden)

    Ryan Kisslinger

    2017-01-01

    Full Text Available Bulk heterojunction solar cells based on blends of quantum dots and conjugated polymers are a promising configuration for obtaining high-efficiency, cheaply fabricated solution-processed photovoltaic devices. Such devices are of significant interest as they have the potential to leverage the advantages of both types of materials, such as the high mobility, band gap tunability and possibility of multiple exciton generation in quantum dots together with the high mechanical flexibility and large molar extinction coefficient of conjugated polymers. Despite these advantages, the power conversion efficiency (PCE of these hybrid devices has remained relatively low at around 6%, well behind that of all-organic or all-inorganic solar cells. This is attributed to major challenges that still need to be overcome before conjugated polymer–quantum dot blends can be considered viable for commercial application, such as controlling the film morphology and interfacial structure to ensure efficient charge transfer and charge transport. In this work, we present our findings with respect to the recent development of bulk heterojunctions made from conjugated polymer–quantum dot blends, list the ongoing strategies being attempted to improve performance, and highlight the key areas of research that need to be pursued to further develop this technology.

  17. Optical properties of bulk semiconductors and graphene/boron nitride: The Bethe-Salpeter equation with derivative discontinuity-corrected density functional energies

    Science.gov (United States)

    Yan, Jun; Jacobsen, Karsten W.; Thygesen, Kristian S.

    2012-07-01

    We present an efficient implementation of the Bethe-Salpeter equation (BSE) for optical properties of materials in the projector augmented wave method Grid-based projector-augmented wave method (GPAW). Single-particle energies and wave functions are obtained from the Gritsenko, Leeuwen, Lenthe, and Baerends potential [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.51.1944 51, 1944 (1995)] with the modifications from Kuisma [Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.82.115106 82, 115106 (2010)] GLLBSC functional which explicitly includes the derivative discontinuity, is computationally inexpensive, and yields excellent fundamental gaps. Electron-hole interactions are included through the BSE using the statically screened interaction evaluated in the random phase approximation. For a representative set of semiconductors and insulators we find excellent agreement with experiments for the dielectric functions, onset of absorption, and lowest excitonic features. For the two-dimensional systems of graphene and hexagonal boron-nitride (h-BN) we find good agreement with previous many-body calculations. For the graphene/h-BN interface we find that the fundamental and optical gaps of the h-BN layer are reduced by 2.0 and 0.7 eV, respectively, compared to freestanding h-BN. This reduction is due to image charge screening which shows up in the GLLBSC calculation as a reduction (vanishing) of the derivative discontinuity.

  18. Semiconductor crystal high resolution imager

    Science.gov (United States)

    Levin, Craig S. (Inventor); Matteson, James (Inventor)

    2011-01-01

    A radiation imaging device (10). The radiation image device (10) comprises a subject radiation station (12) producing photon emissions (14), and at least one semiconductor crystal detector (16) arranged in an edge-on orientation with respect to the emitted photons (14) to directly receive the emitted photons (14) and produce a signal. The semiconductor crystal detector (16) comprises at least one anode and at least one cathode that produces the signal in response to the emitted photons (14).

  19. Electronic structure of semiconductor-metal-semiconductor heterostructures

    Science.gov (United States)

    Masri, Pierre

    For the first time, we present in this article a microscopic self-consistent theory of the electronic structure of semiconductor-metal-semiconductor (SMS) heterostructures. This is done within the framework of a tight-binding approximation. We use a one-band model and a simplified two-band model to describe metal and semiconductor bulk bands, respectively. Results are given for a material-symmetrical and interface-assymetrical SMS structure: this involves the same semiconductors, but different interface polarities (anion- and cation-like interfaces). These results include metal-like states (built-in metal band) and metal-induced semiconductor-like states. The relevance of the charge neutrality condition to this feature and to the determination of the position of the SMS Fermi level is discussed. We also emphasize the confining role of interfaces, with respect to semiconductor-like states, within the semiconductor gap.

  20. III-V semiconductor solid solution single crystal growth

    Science.gov (United States)

    Gertner, E. R.

    1982-01-01

    The feasibility and desirability of space growth of bulk IR semiconductor crystals for use as substrates for epitaxial IR detector material were researched. A III-V ternary compound (GaInSb) and a II-VI binary compound were considered. Vapor epitaxy and quaternary epitaxy techniques were found to be sufficient to permit the use of ground based binary III-V crystals for all major device applications. Float zoning of CdTe was found to be a potentially successful approach to obtaining high quality substrate material, but further experiments were required.

  1. Evaluation of clinical use of OneDose™ metal oxide semiconductor field-effect transistor detectors compared to thermoluminescent dosimeters to measure skin dose for adult patients with acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Huda Ibrahim Al-Mohammed

    2011-01-01

    Full Text Available Background: Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to their bone marrow transplant. It involves the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore, it is important to measure and monitor the skin dose during the treatment. Thermoluminescent dosimeters (TLDs and the OneDose™ metal oxide semiconductor field effect transistor (MOSFET detectors are used during treatment delivery to measure the radiation dose and compare it with the target prescribed dose. Aims: The primary goal of this study was to measure the variation of skin dose using OneDose MOSFET detectors and TLD detectors, and compare the results with the target prescribed dose. The secondary aim was to evaluate the simplicity of use and determine if one system was superior to the other in clinical use. Material and Methods : The measurements involved twelve adult patients diagnosed with acute lymphoblastic leukemia. TLD and OneDose MOSFET dosimetry were performed at ten different anatomical sites of each patient. Results : The results showed that there was a variation between skin dose measured with OneDose MOSFET detectors and TLD in all patients. However, the variation was not significant. Furthermore, the results showed for every anatomical site there was no significant different between the prescribed dose and the dose measured by either TLD or OneDose MOSFET detectors. Conclusion: There were no significant differences between the OneDose MOSFET and TLDs in comparison to the target prescribed dose. However, OneDose MOSFET detectors give a direct read-out immediately after the treatment, and their simplicity of use to compare with TLD detectors may make them preferred for clinical use.

  2. Double peak electric field distortion in heavily irradiated silicon strip detectors

    CERN Document Server

    Eremin, Vladimir; Roe, Shaun; Ruggiero, G; Verbitskaya, E

    2004-01-01

    Non-uniform distribution of the electric field outlined as double peak distortion (DPD) is considered for heavily irradiated silicon strip detectors, which were developed for the CERN-ATLAS semiconductor tracker. DPD originates from the non-uniform accumulation of electrons and holes from the bulk generated current that are captured by radiation induced defects: deep acceptors and donors with mid-gap energy levels. This corresponds to the formation of the low electric field region in the detector central part that consequently will delay charge collection. The electric field distributions at different reverse biases, fluences and detector operational temperatures are calculated using a one-dimensional Poisson equation as it was done earlier for pad detectors. It has been shown that due to the electric field focusing at the strips the DPD effect is more pronounced for strip detectors as compared to that in pad detectors. The double peak electric field distribution is evinced experimentally in current pulse res...

  3. Bulk semiconducting scintillator device for radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Stowe, Ashley C.; Burger, Arnold; Groza, Michael

    2016-08-30

    A bulk semiconducting scintillator device, including: a Li-containing semiconductor compound of general composition Li-III-VI.sub.2, wherein III is a Group III element and VI is a Group VI element; wherein the Li-containing semiconductor compound is used in one or more of a first mode and a second mode, wherein: in the first mode, the Li-containing semiconductor compound is coupled to an electrical circuit under bias operable for measuring electron-hole pairs in the Li-containing semiconductor compound in the presence of neutrons and the Li-containing semiconductor compound is also coupled to current detection electronics operable for detecting a corresponding current in the Li-containing semiconductor compound; and, in the second mode, the Li-containing semiconductor compound is coupled to a photodetector operable for detecting photons generated in the Li-containing semiconductor compound in the presence of the neutrons.

  4. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  5. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  6. Gamma ray detector modules

    Science.gov (United States)

    Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

    2009-01-01

    A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

  7. Effect of radiation induced deep level traps on Si detector performance

    CERN Document Server

    Eremin, V; Li, Z

    2002-01-01

    The main factor, which leads to semiconductor detector degradation in high-energy physics experiments, is the introduction of lattice defects in the detector material produced by radiation. Based on the spectrum of radiation induced defects in the silicon bulk, the overview of effects and mechanisms responsible for the changes in the main detector parameters such as effective concentration of the space charge in the depleted region, space charge sign inversion, charge collection efficiency, and detector breakdown voltage are considered. Special attention is paid to the electric field distortion related with high concentration of radiation induced deep traps, which is the key question for the design of detectors operating at cryogenic temperature. In particular, the charge collection recovery at low temperature, often refereed as the Lazarus effect, and the limitation for the detection rate related to the polarization effect are considered.

  8. WE-G-204-04: Focal Spot Deblurring For High Resolution Amorphous Selenium (aSe) Complementary Metal Oxide Semiconductor (CMOS) X-Ray Detector

    Energy Technology Data Exchange (ETDEWEB)

    Nagesh, S Setlur; Rana, R; Russ, M; Ionita, C; Bednarek, D; Rudin, S [Toshiba Stroke and Vascular Research Center, University at Buffalo, SUNY (United States)

    2015-06-15

    Purpose: CMOS-based aSe detectors compared to CsI-TFT-based flat panels have the advantages of higher spatial sampling due to smaller pixel size and decreased blurring characteristic of direct rather than indirect detection. For systems with such detectors, the limiting factor degrading image resolution then becomes the focal-spot geometric unsharpness. This effect can seriously limit the use of such detectors in areas such as cone beam computed tomography, clinical fluoroscopy and angiography. In this work a technique to remove the effect of focal-spot blur is presented for a simulated aSe detector. Method: To simulate images from an aSe detector affected with focal-spot blur, first a set of high-resolution images of a stent (FRED from Microvention, Inc.) were acquired using a 75µm pixel size Dexela-Perkin-Elmer detector and averaged to reduce quantum noise. Then the averaged image was blurred with a known Gaussian blur at two different magnifications to simulate an idealized focal spot. The blurred images were then deconvolved with a set of different Gaussian blurs to remove the effect of focal-spot blurring using a threshold-based, inverse-filtering method. Results: The blur was removed by deconvolving the images using a set of Gaussian functions for both magnifications. Selecting the correct function resulted in an image close to the original; however, selection of too wide a function would cause severe artifacts. Conclusion: Experimentally, focal-spot blur at different magnifications can be measured using a pin hole with a high resolution detector. This spread function can be used to deblur the input images that are acquired at corresponding magnifications to correct for the focal spot blur. For CBCT applications, the magnification of specific objects can be obtained using initial reconstructions then corrected for focal-spot blurring to improve resolution. Similarly, if object magnification can be determined such correction may be applied in fluoroscopy and

  9. Development of TiBr semiconductor crystal for applications as radiation detector and photodetector; Desenvolvimento do cristal semicondutor de brometo de talio para aplicacoes como detector de radiacao e fotodetector

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Icimone Braga de

    2006-07-01

    In this work, Tlbr crystals were grown by the Bridgman method from zone melted materials. The influence of the purification efficiency and the crystalline surface quality on the crystal were studied, evaluating its performance as a radiation detector. Due to significant improvement in the purification and crystals growth, good results have been obtained for the developed detectors. The spectrometric performance of the Tlbr detector was evaluated by {sup 241}Am (59 keV), {sup 133}Ba (80 e 355 keV), {sup 57}Co (122 keV), {sup 22}Na (511 keV) and {sup 137} Cs (662 keV) at room temperature. The best energy resolution results were obtained from purer detectors. Energy resolutions of 10 keV (16%), 12 keV (15%), 12 keV (10%), 28 keV (8%), 31 keV (6%) and 36 keV (5%) to 59, 80, 122, 355, 511 and 662 keV energies, respectively, were obtained. A study on the detection response at -20 deg C was also carried out, as well as the detector stability in function of the time. No significant difference was observed in the energy resolution between measurements at both temperatures. It was observed that the detector instability causes degradation of the spectroscopic characteristics during measurements at room temperature and the instability varies for each detector. This behavior was also verified by other authors. The viability to use the developed Tlbr crystal as a photodetector coupled to scintillators crystals was also studied in this work. Due to its quantum efficiency in the region from 350 to 500 nm, Tlbr shows to be a promising material to be used as a photodetector. As a possible application of this work, the development of a surgical probe has been initiated using the developed Tlbr crystal as the radiation detector of the probe. (author)

  10. Surface Leakage Mechanisms in III-V Infrared Barrier Detectors

    Science.gov (United States)

    Sidor, D. E.; Savich, G. R.; Wicks, G. W.

    2016-09-01

    Infrared detector epitaxial structures employing unipolar barriers exhibit greatly reduced dark currents compared to simple pn-based structures. When correctly positioned within the structure, unipolar barriers are highly effective at blocking bulk dark current mechanisms. Unipolar barriers are also effective at suppressing surface leakage current in infrared detector structures employing absorbing layers that possess the same conductivity type in their bulk and at their surface. When an absorbing layer possesses opposite conductivity types in its bulk and at its surface, unipolar barriers are not solutions to surface leakage. This work reviews empirically determined surface band alignments of III-V semiconductor compounds and modeled surface band alignments of both gallium-free and gallium-containing type-II strained layer superlattice material systems. Surface band alignments are used to predict surface conductivity types in several detector structures, and the relationship between surface and bulk conductivity types in the absorbing layers of these structures is used as the basis for explaining observed surface leakage characteristics.

  11. Second harmonic spectroscopy of semiconductor nanostructures

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Yu, Ping; Bozhevolnyi, Sergey I.

    1999-01-01

    Semiconductor nanostructures and their application to optoelectronic devices have attracted much attention recently. Lower-dimensional structures, and in particular quantum dots, are highly anisotropic resulting in broken symmetry as compared to their bulk counterparts. This is not only reflected...

  12. Coated semiconductor devices for neutron detection

    Energy Technology Data Exchange (ETDEWEB)

    Klann, Raymond T. (Bolingbrook, IL); McGregor, Douglas S. (Whitmore Lake, MI)

    2002-01-01

    A device for detecting neutrons includes a semi-insulated bulk semiconductor substrate having opposed polished surfaces. A blocking Schottky contact comprised of a series of metals such as Ti, Pt, Au, Ge, Pd, and Ni is formed on a first polished surface of the semiconductor substrate, while a low resistivity ("ohmic") contact comprised of metals such as Au, Ge, and Ni is formed on a second, opposed polished surface of the substrate. In one embodiment, n-type low resistivity pinout contacts comprised of an Au/Ge based eutectic alloy or multi-layered Pd/Ge/Ti/Au are also formed on the opposed polished surfaces and in contact with the Schottky and ohmic contacts. Disposed on the Schottky contact is a neutron reactive film, or coating, for detecting neutrons. The coating is comprised of a hydrogen rich polymer, such as a polyolefin or paraffin; lithium or lithium fluoride; or a heavy metal fissionable material. By varying the coating thickness and electrical settings, neutrons at specific energies can be detected. The coated neutron detector is capable of performing real-time neutron radiography in high gamma fields, digital fast neutron radiography, fissile material identification, and basic neutron detection particularly in high radiation fields.

  13. Comprehensive measurements of GaAs pixel detectors capacitance

    CERN Document Server

    Caria, M; D'Auria, S; Lai, A; Randaccio, P; Cadeddu, S

    2002-01-01

    We have studied GaAs pixel detectors on semi-insulating wafers with Schottky contacts. We performed comprehensive measurements on the inter-pixel and capacitance to back plane. Being semi-insulating, the behaviour is totally different with respect to other common semiconductors, such as high resistivity silicon. Non-homogeneities are also an issue, due to both the contacts and the crystal bulk. In order to detect them and their influence on capacitance, we undertook systematic measurements with different configurations of the measuring electrodes.

  14. Technology development of 3D detectors for high energy physics and medical imaging

    CERN Document Server

    Pellegrini, G

    2003-01-01

    This thesis is concerned with the fabrication, characterisation and simulation of 3D semiconductor detectors. Due to their geometry, these detectors have more efficient charge collection properties than current silicon and gallium arsenide planar detectors. The unit cell of these detectors is hexagonal with a central anode surrounded by six cathode contacts. This geometry gives a uniform electric field with the maximum drift and depletion distance set by electrode spacing, 85m in this project, rather than detector thickness, as in the case of planar detectors (typically 100-300m). This results in lower applied biases (35-40 V in the work of this project) compared to >200 V in typical planar detectors. The reduction in bias offers the possibility of improved detector operation in the presence of bulk radiation damage as lower voltage reduces leakage current which limits the signal to noise ratio and hence the overall detector efficiency. In this work, 3D detectors realised in Si, GaAs and SiC have ...

  15. High-resolution ionization detector and array of such detectors

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  16. Silicon Drift Detectors for ALICE

    CERN Document Server

    Navach, F; CERN. Geneva

    1992-01-01

    The Silicon Drift Detector (SDD) is a semiconductor, not yet extensively used in HEP experiment, which has an excellent spatial resolution and granularity about comparable to a pixel device requiring a number of readout channels two order of magnitude less.

  17. Effects of spatial confinement on conduction electrons in semiconductor nanostructures

    NARCIS (Netherlands)

    Germeau, Alexander

    2003-01-01

    Semiconductor nanostructures show electrical and optical properties which can be very different from bulk semiconductors. The various effects that occur due to the spatial confinement of electrons in such structures are of scientific importance. In addition, semiconductor nanostructures are very pro

  18. Ultrafast Degenerate Transient Lens Spectroscopy in Semiconductor Nanosctructures

    Directory of Open Access Journals (Sweden)

    Leontyev A.V.

    2015-01-01

    Full Text Available We report the non-resonant excitation and probing of the nonlinear refractive index change in bulk semiconductors and semiconductor quantum dots through degenerate transient lens spectroscopy. The signal oscillates at the center laser field frequency, and the envelope of the former in quantum dots is distinctly different from the one in bulk sample. We discuss the applicability of this technique for polarization state probing in semiconductor media with femtosecond temporal resolution.

  19. Semiconductor spintronics

    CERN Document Server

    Xia, Jianbai; Chang, Kai

    2012-01-01

    Semiconductor Spintronics, as an emerging research discipline and an important advanced field in physics, has developed quickly and obtained fruitful results in recent decades. This volume is the first monograph summarizing the physical foundation and the experimental results obtained in this field. With the culmination of the authors' extensive working experiences, this book presents the developing history of semiconductor spintronics, its basic concepts and theories, experimental results, and the prospected future development. This unique book intends to provide a systematic and modern foundation for semiconductor spintronics aimed at researchers, professors, post-doctorates, and graduate students, and to help them master the overall knowledge of spintronics.

  20. Porous and Nanoporous Semiconductors and Emerging Applications

    Directory of Open Access Journals (Sweden)

    Helmut Föll

    2006-01-01

    Full Text Available Pores in single-crystalline semiconductors can be produced in a wide range of geometries and morphologies, including the “nanometer” regime. Porous semiconductors may have properties completely different from the bulk, and metamaterials with, for example, optical properties not encountered in natural materials are emerging. Possible applications of porous semiconductors include various novel sensors, but also more “exotic” uses as, for example, high explosives or electrodes for micro-fuel cells. The paper briefly reviews pore formation (including more applied aspects of large area etching, properties of porous semiconductors, and emerging applications.

  1. Device Physics of Narrow Gap Semiconductors

    CERN Document Server

    Chu, Junhao

    2010-01-01

    Narrow gap semiconductors obey the general rules of semiconductor science, but often exhibit extreme features of these rules because of the same properties that produce their narrow gaps. Consequently these materials provide sensitive tests of theory, and the opportunity for the design of innovative devices. Narrow gap semiconductors are the most important materials for the preparation of advanced modern infrared systems. Device Physics of Narrow Gap Semiconductors offers descriptions of the materials science and device physics of these unique materials. Topics covered include impurities and defects, recombination mechanisms, surface and interface properties, and the properties of low dimensional systems for infrared applications. This book will help readers to understand not only the semiconductor physics and materials science, but also how they relate to advanced opto-electronic devices. The last chapter applies the understanding of device physics to photoconductive detectors, photovoltaic infrared detector...

  2. Effects of substrate voltage on noise characteristics and hole lifetime in SOI metal-oxide-semiconductor field-effect transistor photon detector.

    Science.gov (United States)

    Putranto, Dedy Septono Catur; Priambodo, Purnomo Sidi; Hartanto, Djoko; Du, Wei; Satoh, Hiroaki; Ono, Atsushi; Inokawa, Hiroshi

    2014-09-08

    Low-frequency noise and hole lifetime in silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) are analyzed, considering their use in photon detection based on single-hole counting. The noise becomes minimum at around the transition point between front- and back-channel operations when the substrate voltage is varied, and increases largely on both negative and positive sides of the substrate voltage showing peculiar Lorentzian (generation-recombination) noise spectra. Hole lifetime is evaluated by the analysis of drain current histogram at different substrate voltages. It is found that the peaks in the histogram corresponding to the larger number of stored holes become higher as the substrate bias becomes larger. This can be attributed to the prolonged lifetime caused by the higher electric field inside the body of SOI MOSFET. It can be concluded that, once the inversion channel is induced for detection of the photo-generated holes, the small absolute substrate bias is favorable for short lifetime and low noise, leading to high-speed operation.

  3. Semiconductor heterojunctions

    CERN Document Server

    Sharma, B L

    1974-01-01

    Semiconductor Heterojunctions investigates various aspects of semiconductor heterojunctions. Topics covered include the theory of heterojunctions and their energy band profiles, electrical and optoelectronic properties, and methods of preparation. A number of heterojunction devices are also considered, from photovoltaic converters to photodiodes, transistors, and injection lasers.Comprised of eight chapters, this volume begins with an overview of the theory of heterojunctions and a discussion on abrupt isotype and anisotype heterojunctions, along with graded heterojunctions. The reader is then

  4. Synthesis, purification, and characterization of perovskite semiconductor CsPbBr3 as a new candidate for y-ray detector(Conference Presentation)

    Science.gov (United States)

    Chung, Duck Young; Kanatzidis, Mercouri G.; Meng, Fang; Malliakas, Christos D.

    2016-09-01

    CsPbBr3 has direct band gap (orange color, 2.25 eV), high density (4.85 g/cm3), attenuation coefficient comparable to CZT, and high resistivity 10^9 ohm•cm. These fundamental physical properties of CsPbBr3well meet the requirements for gamma-ray detector materials. CsPbBr3 exhibits the carrier mobility-lifetime product in the order of 10^-4 cm2/V promising enough to be further developed for practical applications. The major challenge in the process to further enhance the detection performance is the carrier traps present at a deep level of the energy gap which should be minimized. We report the synthesis, purification, crystal growth and physical characterization of the CsPbBr3 crystals obtained by new processes we developed for highly pure materials with reduced carrier traps. The starting binary materials were prepared by reaction of Cs2CO3/HBr and Pb(ac)2/HBr in aqueous solution. Purification of materials was performed by sublimation, bromination with HBr gas, and filtration of molten materials. Large single crystals were grown by the vertical Bridgman and EelectroDynamic Gradient method and cut to the dimensions appropriate for assessment of the material for gamma-ray detector applications. All characterization including optical characteristics, charge transport properties, photoconductivity, and gamma-ray spectroscopy from the new single crystals of CsPbBr3 will be presented. In addition, the charge carrier traps profile has been studied for this compound by Deep-Level Transient Spectroscopy (DLTS), Thermally Stimulated Luminescence (TSL), and Photoluminescence (PL) and will be presented.

  5. Basic properties of semiconductors

    CERN Document Server

    Landsberg, PT

    2013-01-01

    Since Volume 1 was published in 1982, the centres of interest in the basic physics of semiconductors have shifted. Volume 1 was called Band Theory and Transport Properties in the first edition, but the subject has broadened to such an extent that Basic Properties is now a more suitable title. Seven chapters have been rewritten by the original authors. However, twelve chapters are essentially new, with the bulk of this work being devoted to important current topics which give this volume an almost encyclopaedic form. The first three chapters discuss various aspects of modern band theory and the

  6. Collective excitations of spherical semiconductor nanoparticles

    Science.gov (United States)

    Moradi, Afshin

    2016-10-01

    In this article, we study the dispersion properties of bulk and surface electrostatic oscillations of a spherical quantum electron-hole semiconductor plasma as a simple model of a semiconductor nanoparticle. We derive general dispersion relation for both bulk and surface modes, using quantum hydrodynamic theory (including the electrons and holes quantum recoil effects, quantum statistical pressures of the plasma species, as well as exchange and correlation effects) in conjunction with Poisson’s equation and appropriate boundary conditions. We show that for the arbitrary value of angular quantum number {\\ell }≥slant 1 there are only two surface plasmon modes, but two infinite series of bulk modes for {\\ell }≥slant 0 that owe their existence to the curvature of the interface. We use the typical values of GaAs semiconductor to compute the bulk and surface mode frequencies for different value of {\\ell }.

  7. Radiation detectors laboratory; Laboratorio de detectores de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  8. Semiconductors and semimetals epitaxial microstructures

    CERN Document Server

    Willardson, Robert K; Beer, Albert C; Gossard, Arthur C

    1994-01-01

    Newly developed semiconductor microstructures can now guide light and electrons resulting in important consequences for state-of-the-art electronic and photonic devices. This volume introduces a new generation of epitaxial microstructures. Special emphasis has been given to atomic control during growth and the interrelationship between the atomic arrangements and the properties of the structures.Key Features* Atomic-level control of semiconductor microstructures* Molecular beam epitaxy, metal-organic chemical vapor deposition* Quantum wells and quantum wires* Lasers, photon(IR)detectors, heterostructure transistors

  9. 3D silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Parzefall, Ulrich [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany)], E-mail: ulrich.parzefall@physik.uni-freiburg.de; Bates, Richard [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Boscardin, Maurizio [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Dalla Betta, Gian-Franco [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Eckert, Simon [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Eklund, Lars; Fleta, Celeste [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Jakobs, Karl; Kuehn, Susanne [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Lozano, Manuel [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pahn, Gregor [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Parkes, Chris [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Pellegrini, Giulio [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pennicard, David [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Piemonte, Claudio; Ronchin, Sabina [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Szumlak, Tomasz [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Zoboli, Andrea [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Zorzi, Nicola [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy)

    2009-06-01

    While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2-3 cm length are foreseen to cover the region from 28 to 60 cm distance to the beam. These SSD will be exposed to radiation levels up to 10{sup 15}N{sub eq}/cm{sup 2}, which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of 10{sup 15}N{sub eq}/cm{sup 2}. The tests were performed with three systems: a highly focused IR-laser with 5{mu}m spot size to make position-resolved scans of the charge collection efficiency, an Sr{sup 90}{beta}-source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180 GeV pions at CERN. This article gives a brief overview of

  10. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1962-01-01

    Semiconductor Statistics presents statistics aimed at complementing existing books on the relationships between carrier densities and transport effects. The book is divided into two parts. Part I provides introductory material on the electron theory of solids, and then discusses carrier statistics for semiconductors in thermal equilibrium. Of course a solid cannot be in true thermodynamic equilibrium if any electrical current is passed; but when currents are reasonably small the distribution function is but little perturbed, and the carrier distribution for such a """"quasi-equilibrium"""" co

  11. Oxide semiconductors

    CERN Document Server

    Svensson, Bengt G; Jagadish, Chennupati

    2013-01-01

    Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. Originally widely known as the ""Willardson and Beer"" Series, it has succeeded in publishing numerous landmark volumes and chapters. The series publishes timely, highly relevant volumes intended for long-term impact and reflecting the truly interdisciplinary nature of the field. The volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in academia, scient

  12. Ion chamber based neutron detectors

    Science.gov (United States)

    Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

    2014-12-16

    A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

  13. Broadband fast semiconductor saturable absorber.

    Science.gov (United States)

    Jacobovitz-Veselka, G R; Kellerm, U; Asom, T

    1992-12-15

    Kerr lens mode-locked (KLM) solid-state lasers are typically not self-starting. We address this problem by introducing a broadband semiconductor saturable absorber that could be used as a tunable, all-solid-state, passive starting mechanism. We extend the wavelength tunability of a semiconductor saturable absorber to more than 100 nm using a band-gap-engineered low-temperature molecular-beam-epitaxy (MBE)-grown bulk AlGaAs semiconductor saturable absorber in which the absorption edge of the saturable absorber has been artificially broadened by continuously reducing the Al concentration during the MBE growth. We demonstrate its tunability and its feasibility as a starting mechanism for KLM with a picosecond resonant passive mode-locked Ti:sapphire laser. The extension to femtosecond KLM lasers has been discussed previously.

  14. Organic Semiconductors and its Applications

    Science.gov (United States)

    Kamalasanan, M. N.

    2011-10-01

    Organic semiconductors in the form of evaporated or spin coated thin films have many optoelectronic applications in the present electronic industry. They are frequently used in many type of displays, photo detectors, photoconductors for photocopiers and photovoltaic cells. But many p-conjugated molecules and polymer based devices do not provide satisfactory device performance and operational stability. Most of these problems are related to the interfaces they make with other organic materials and electrodes and the low conductivity of the organic layers. The study of organic-metal and organic—organic interfaces as well as electrical doping of organic semiconductors are very important areas of research at present. In this talk, I will be discussing some of the recent advances in this field as well as some of our own results in the area of interface modification and electrical doping of organic semiconductors.

  15. Use of semiconductor detector c-Si microstrip type in obtaining the digital radiographic imaging of phantoms and biological samples of mammary glands; Empleo de detector semiconductor de c-Si del tipo microbandas en la obtencion de imagenes radiograficas digitales de maniquies y muestras biologicas de mamas

    Energy Technology Data Exchange (ETDEWEB)

    Leyva, A.; Cabal, A.; Pinera, I.; Abreu, Y.; Cruz, C. M. [Centro de Estudios Avanzados y Desarrollo Nuclear, C. Habana, Cuba (Cuba); Montano, L. M.; Diaz, C. C.; Fontaine, M. [IPN, Centro de Investigaciones y Estudios Avanzados, Mexico D. F. (Mexico); Ortiz, C. M. [ISSSTE, Hospital General Tacuba, Clinica de Mama y Gineco-oncologia, Mexico D. F. (Mexico); Padilla, F. [Instituto Superior de Tecnologias y Ciencias Aplicadas, C. Habana, Cuba (Cuba); De la Mora, R. [Centro de Control Estatal de Equipos Medicos, C. Habana, Cuba (Cuba)], e-mail: aleyva@ceaden.edu.cu

    2009-07-01

    The present work synthesizes the experimental results obtained in the characterization of 64 micro strips crystalline silicon detector designed for experiments in high energies physics, with the objective of studying its possible application in advanced medical radiography, specifically in digital mammography and angiography. The research includes the acquisition of two-dimensional radiography of a mammography phantom using the scanning method, and its comparison with similar images simulated mathematically for different X rays sources. The paper also shows the experimental radiography of two biological samples taken from biopsies of mammas, where it is possible to identify the presence of possible pathological lesions. The results reached in this work point positively toward the effective possibility of satisfactorily introducing those advanced detectors in medical digital imaging applications. (Author)

  16. Gain and Index Dynamics in Semiconductor Lasers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    Semiconductor optical amplifiers (SOAs) provide ultrafast, i.e. broadband components for optical communication systems. They enter not only as signal generators and amplifiers, but also as nonlinear elements for ultrafast signal processing such as wavelength conversion, switching, and regeneration...... changed character from bulk semiconductor to quantum wells and most recently to quantum dots. By quantum confinement of the carriers, the light-matter interactions can be significantly modified and the optical properties, including dynamics, can be engineered to match the required functionalities...

  17. Work on the ATLAS semiconductor tracker barrel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    Precision work is performed on the semiconductor tracker barrel of the ATLAS experiment. All work on these delicate components must be performed in a clean room so that impurities in the air, such as dust, do not contaminate the detector. The semiconductor tracker will be mounted in the barrel close to the heart of the ATLAS experiment to detect the path of particles produced in proton-proton collisions.

  18. Nitride semiconductor devices fundamentals and applications

    CERN Document Server

    Morkoç, Hadis

    2013-01-01

    This book gives a clear presentation of the necessary basics of semiconductor and device physics and engineering. It introduces readers to fundamental issues that will enable them to follow the latest technological research. It also covers important applications, including LED and lighting, semiconductor lasers, high power switching devices, and detectors. This balanced and up-to-date treatment makes the text an essential educational tool for both advanced students and professionals in the electronics industry.

  19. Acoustoelectric effect in semiconductor superlattice

    Science.gov (United States)

    Mensah, S. Y.; Allotey, F. K. A.; Adjepong, S. K.

    1993-10-01

    Acoustoelectric effect in semiconductor superlattice has been studied for acoustic wave whose wavelength lambda = 2pi/q is smaller than the mean free path of the electrons l (where ql approaches 1). Unlike the homogeneous bulk material where Weinreich relation is independent of the wave number q in the superlattice we observe a dependence on q i.e. spatial dispersion. In the presence of applied constant field E a threshold value was obtained where the acoustoelectric current changes direction.

  20. Semiconductor Optics

    CERN Document Server

    Klingshirn, Claus F

    2012-01-01

    This updated and enlarged new edition of Semiconductor Optics provides an introduction to and an overview of semiconductor optics from the IR through the visible to the UV, including linear and nonlinear optical properties, dynamics, magneto and electrooptics, high-excitation effects and laser processes, some applications, experimental techniques and group theory. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered extend from physics to materials science and optoelectronics. Significantly updated chapters add coverage of current topics such as electron hole plasma, Bose condensation of excitons and meta materials. Over 120 problems, chapter introductions and a detailed index make it the key textbook for graduate students in physics. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered ...

  1. Semiconductor switch geometry with electric field shaping

    Science.gov (United States)

    Booth, Rex; Pocha, Michael D.

    1994-01-01

    An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sfyrla, Anna [Univ. of Geneva (Switzerland)

    2008-03-10

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

  3. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.

    2002-01-01

    -power surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier...... is biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...

  4. Cryogenic semiconductor high-intensity radiation monitors

    CERN Document Server

    Palmieri, V G; Borer, K; Casagrande, L; Da Vià, C; Devine, S R H; Dezillie, B; Esposito, A; Granata, V; Hauler, F; Jungermann, L; Li, Z; Lourenço, C; Niinikoski, T O; O'Shea, V

    2003-01-01

    This paper describes a novel technique to monitor high-intensity particle beams by means of a semiconductor detector. It consists of cooling a semiconductor detector down to cryogenic temperature to suppress the thermally generated leakage current and to precisely measure the integrated ionization signal. It will be shown that such a device provides very good linearity and a dynamic range wider than is possible with existing techniques. Moreover, thanks to the Lazarus effect, extreme radiation hardness can be achieved providing in turn absolute intensity measurements against precise calibration of the device at low beam flux.

  5. Particlc detectors. Foundations and applications; Teilchendetektoren. Grundlagen und Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Kolanoski, Hermann; Wermes, Norbert

    2016-08-01

    The following topics are dealt with: Interaction of particles with matter, motion of charge carriers in electric and magnetic fields, signal generation by moving charges, non-electronic detectors, gas-filled detectors, semiconductor detectors, track reconstruction and momentum measurement, photodetectors, Cherenkov detectors, transition-radiation detectors, scintillation detectors, particle identification, calorimeters, detection of cosmic particles, signal processing and noise, trigger and data acquisition systems. (HSI)

  6. Quantum theory of the optical and electronic properties of semiconductors

    CERN Document Server

    Haug, Hartmut

    2009-01-01

    This invaluable textbook presents the basic elements needed to understand and research into semiconductor physics. It deals with elementary excitations in bulk and low-dimensional semiconductors, including quantum wells, quantum wires and quantum dots. The basic principles underlying optical nonlinearities are developed, including excitonic and many-body plasma effects. Fundamentals of optical bistability, semiconductor lasers, femtosecond excitation, the optical Stark effect, the semiconductor photon echo, magneto-optic effects, as well as bulk and quantum-confined Franz-Keldysh effects, are covered. The material is presented in sufficient detail for graduate students and researchers with a general background in quantum mechanics.This fifth edition includes an additional chapter on 'Quantum Optical Effects' where the theory of quantum optical effects in semiconductors is detailed. Besides deriving the 'semiconductor luminescence equations' and the expression for the stationary luminescence spectrum, the resu...

  7. Semiconductor laser

    Energy Technology Data Exchange (ETDEWEB)

    Ito, K.; Shyuue, M.

    1982-09-25

    A distributed feedback semiconductor laser is proposed which generates several beams with equal wavelengths in different directions. For this purpose, 1 millimeter grooves are cut into the surface of an n-type conductance GaAs plate in three different directions; these grooves form a diffraction grating. The center of this plate has no grooves and is bombarded by an He/Ne laser beam. The diffraction gratings provide resonance properties and generate laser beams with wavelengths of 8850, 9000 and 9200 angstroms.

  8. Position-sensitive superconductor detectors

    Science.gov (United States)

    Kurakado, M.; Taniguchi, K.

    2016-12-01

    Superconducting tunnel junction (STJ) detectors and superconducting transition- edge sensors (TESs) are representative superconductor detectors having energy resolutions much higher than those of semiconductor detectors. STJ detectors are thin, thereby making it suitable for detecting low-energy X rays. The signals of STJ detectors are more than 100 times faster than those of TESs. By contrast, TESs are microcalorimeters that measure the radiation energy from the change in the temperature. Therefore, signals are slow and their time constants are typically several hundreds of μs. However, TESs possess excellent energy resolutions. For example, TESs have a resolution of 1.6 eV for 5.9-keV X rays. An array of STJs or TESs can be used as a pixel detector. Superconducting series-junction detectors (SSJDs) comprise multiple STJs and a single-crystal substrate that acts as a radiation absorber. SSJDs are also position sensitive, and their energy resolutions are higher than those of semiconductor detectors. In this paper, we give an overview of position-sensitive superconductor detectors.

  9. Power semiconductors

    CERN Document Server

    Kubát, M

    1984-01-01

    The book contains a summary of our knowledge of power semiconductor structures. It presents first a short historic introduction (Chap. I) as well as a brief selection of facts from solid state physics, in particular those related to power semiconductors (Chap. 2). The book deals with diode structures in Chap. 3. In addition to fundamental facts in pn-junction theory, the book covers mainly the important processes of power structures. It describes the emitter efficiency and function of microleaks (shunts). the p +p and n + n junctions, and in particular the recent theory of the pin, pvn and p1tn junctions, whose role appears to be decisive for the forward mode not only of diode structures but also of more complex ones. For power diode structures the reverse mode is the decisive factor in pn-junction breakdown theory. The presentation given here uses engineering features (the multiplication factor M and the experimentally detected laws for the volume and surface of crystals), which condenses the presentation an...

  10. Magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bihler, Christoph

    2009-04-15

    In this thesis we investigated in detail the properties of Ga{sub 1-x}Mn{sub x}As, Ga{sub 1-x}Mn{sub x}P, and Ga{sub 1-x}Mn{sub x}N dilute magnetic semiconductor thin films with a focus on the magnetic anisotropy and the changes of their properties upon hydrogenation. We applied two complementary spectroscopic techniques to address the position of H in magnetic semiconductors: (i) Electron paramagnetic resonance, which provides direct information on the symmetry of the crystal field of the Mn{sup 2+} atoms and (ii) x-ray absorption fine structure analysis which allows to probe the local crystallographic neighborhood of the absorbing Mn atom via analysing the fine structure at the Mn K absorption edge. Finally, we discussed the obstacles that have to be overcome to achieve Curie temperatures above the current maximum in Ga{sub 1-x}Mn{sub x}As of 185 K. Here, we outlined in detail the generic problem of the formation of precipitates at the example of Ge:MN. (orig.)

  11. Semiconductor Laser Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Laser Measurements Laboratory is equipped to investigate and characterize the lasing properties of semiconductor diode lasers. Lasing features such...

  12. Thin Film Compound Semiconductor Devices for Photonic Interconnects

    Science.gov (United States)

    Calhoun, Kenneth Harold

    The research conducted for this doctoral dissertation involved the experimental investigation of thin film compound devices for use as photonic interconnection components in both external and direct modulated interconnection configurations. The devices were fabricated using a modified epitaxial liftoff procedure developed at Georgia Tech. This technique, by which single crystal semiconductor layers were separated from their growth substrate and subsequently deposited onto host substrates, allowed the development of novel photonic interconnection elements. It also facilitated the investigation of fundamental optical phenomena in compound semiconductors. Specifically, this work focused on an experimental study of the Franz-Keldysh electrorefractive effect in thin film semiconductor structures. This aspect of the research resulted in the first reported direct measurement of electrorefraction in GaAs at large electric fields (10 ^5 V/cm) and at photon energies within several meV of the band edge of GaAs. Related to this effort was the investigation of thin film, surface-normal optical modulators based on the bulk Franz-Keldysh effect. The novel modulators fabricated for this research demonstrated the largest contrast ratios ever reported for surface-normal Franz-Keldysh devices. Further investigation indicated that, with additional optimization, these thin film elements can achieve further improvements in performance. Such devices would present a low cost, easily manufactured alternative to conventional modulators, which are typically quite complex and expensive to fabricate. Finally, as an alternative to externally modulated interconnection schemes, a novel stacked wafer architecture was demonstrated. This configuration, which facilitated through-wafer optical communication, utilized thin film InP/InGaAsP emitters and detectors which were quasi-monolithically integrated onto silicon substrates using the modified epitaxial liftoff process. This through-wafer scheme is

  13. The principle and application of metal oxide semiconductor field effect transistor detector during radiotherapy%金属氧化物半导体场效应晶体管剂量探测器的工作原理及在放射治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    倪园园; 涂彧

    2008-01-01

    Metal oxide semiconductor field effect transistor (MOSFET) detector was used to measure radiation dose in space initially, and it was applied to medical domain in recent years. MOSFET detector had extent prospect in clinical field because it had the advantages that other nomal detectors couldn' t compare with. This article introduced the application of MOSFET detector in radiotherapy by summarizing its basic principle, the principle of measuring dose and the relative characteristics.%金属氧化物半导体场效应晶体管(MOSFET)探测器原用于空间系统的辐射测量,近几年才引入到医学领域.由于该探测器具有普通探测设备无法比拟的优点,因此在临床有广泛的应用前景.通过概述MOSFET 20探测器的基本工作原理、剂量探测原理及其相关特性,介绍了MOSFET探测器在放射治疗中的应用.

  14. 2010 Defects in Semiconductors GRC

    Energy Technology Data Exchange (ETDEWEB)

    Shengbai Zhang

    2011-01-06

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, as well as an emphasis on the development of novel defect detection methods and first-principles defect theories. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference will deal with point and extended defects in a broad range of electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, oxides, sp{sup 2} carbon based-materials, and photovoltaic/solar cell materials, and in understanding important defect phenomena such as doping bottleneck in nanostructures and the diffusion of defects and impurities. The program consists of about twenty invited talks and a number of contributed poster sessions. The emphasis should be on work which has yet to be published. The large amount of discussion time provides an ideal forum for dealing with topics that are new and/or controversial.

  15. High throughput combinatorial screening of semiconductor materials

    Science.gov (United States)

    Mao, Samuel S.

    2011-11-01

    This article provides an overview of an advanced combinatorial material discovery platform developed recently for screening semiconductor materials with properties that may have applications ranging from radiation detectors to solar cells. Semiconductor thin-film libraries, each consisting of 256 materials of different composition arranged into a 16×16 matrix, were fabricated using laser-assisted evaporation process along with a combinatorial mechanism to achieve variations. The composition and microstructure of individual materials on each thin-film library were characterized with an integrated scanning micro-beam x-ray fluorescence and diffraction system, while the band gaps were determined by scanning optical reflection and transmission of the libraries. An ultrafast ultraviolet photon-induced charge probe was devised to measure the mobility and lifetime of individual thin-film materials on semiconductor libraries. Selected results on the discovery of semiconductors with desired band gaps and transport properties are illustrated.

  16. Combining two major ATLAS inner detector components

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The semiconductor tracker is inserted into the transition radiation tracker for the ATLAS experiment at the LHC. These make up two of the three major components of the inner detector. They will work together to measure the trajectories produced in the proton-proton collisions at the centre of the detector when the LHC is switched on in 2008.

  17. Spectroscopic analysis of optoelectronic semiconductors

    CERN Document Server

    Jimenez, Juan

    2016-01-01

    This book deals with standard spectroscopic techniques which can be used to analyze semiconductor samples or devices, in both, bulk, micrometer and submicrometer scale. The book aims helping experimental physicists and engineers to choose the right analytical spectroscopic technique in order to get specific information about their specific demands. For this purpose, the techniques including technical details such as apparatus and probed sample region are described. More important, also the expected outcome from experiments is provided. This involves also the link to theory, that is not subject of this book, and the link to current experimental results in the literature which are presented in a review-like style. Many special spectroscopic techniques are introduced and their relationship to the standard techniques is revealed. Thus the book works also as a type of guide or reference book for people researching in optical spectroscopy of semiconductors.

  18. Superheating Suppresses Structural Disorder in Layered BiI3 Semiconductors Grown by the Bridgman Method

    Energy Technology Data Exchange (ETDEWEB)

    Johns, Paul M.; Sulekar, Soumitra; Yeo, Shinyoung; Baciak, James E.; Bliss, Mary; Nino, Juan C.

    2016-01-01

    The susceptibility of layered structures to stacking faults is a problem in some of the more attractive semiconductor materials for ambient-temperature radiation detectors. In the work presented here, Bridgman-grown BiI3 layered single crystals are investigated to understand and eliminate this structural disorder, which reduces radiation detector performance. The use of superheating gradients has been shown to improve crystal quality in non-layered semiconductor crystals; thus the technique was here explored to improve the growth of BiI3. When investigating the homogeneity of non-superheated crystals, highly geometric void defects were found to populate the bulk of the crystals. Applying a superheating gradient to the melt prior to crystal growth improved structural quality and decreased defect density from the order of 4600 voids per cm3 to 300 voids per cm3. Corresponding moderate improvements to electronic properties also resulted from the superheat gradient method of crystal growth. Comparative measurements through infrared microscopy, etch-pit density, x-ray rocking curves, and sheet resistivity readings show that superheat gradients in BiI3 growth led to higher quality crystals.

  19. Superheating suppresses structural disorder in layered BiI3 semiconductors grown by the Bridgman method

    Science.gov (United States)

    Johns, Paul M.; Sulekar, Soumitra; Yeo, Shinyoung; Baciak, J. E.; Bliss, Mary; Nino, Juan C.

    2016-01-01

    The susceptibility of layered structures to stacking faults is a problem in some of the more attractive semiconductor materials for ambient-temperature radiation detectors. In this work, Bridgman-grown BiI3 layered single crystals are investigated to understand and eliminate structural disorder, which reduces radiation detector performance. The use of superheating gradients has been shown by others to improve crystal quality in non-layered semiconductor crystals (Rudolph et al., 1996) [26]; thus the technique was explored to improve the growth of BiI3. When investigating the homogeneity of non-superheated crystals, highly geometric void defects were found to populate the bulk of the crystals. Applying a superheating gradient to the melt prior to crystal growth improved structural quality and decreased defect density from the order of 4600 voids per cm3 to 300 voids per cm3. Corresponding moderate improvements to electronic properties also resulted from the superheat gradient method of crystal growth. Comparative measurements through infrared microscopy, etch-pit density, X-ray rocking curves, and sheet resistivity readings show that superheat gradients in BiI3 growth led to higher quality crystals.

  20. Semiconductor laser. Halbleiterlaser

    Energy Technology Data Exchange (ETDEWEB)

    Wuenstel, K.; Gohla, B.; Tegude, F.; Luz, G.; Hildebrand, O.

    1987-08-27

    A highly modulable semiconductor laser and a process for its manufacture are described. The semiconductor laser has a substrate, a stack of semiconductor layers and electrical contacts. To reduce the capacity, the width of the stack of semiconductor layers is reduced at the sides by anisotropic etching. The electrical contacts are situated on the same side of the substrate and are applied in the same stage of the process. The semiconductor laser is suitable for monolithic integration in other components.

  1. Nanofluidics, from bulk to interfaces.

    Science.gov (United States)

    Bocquet, Lydéric; Charlaix, Elisabeth

    2010-03-01

    Nanofluidics has emerged recently in the footsteps of microfluidics, following the quest for scale reduction inherent to nanotechnologies. By definition, nanofluidics explores transport phenomena of fluids at nanometer scales. Why is the nanometer scale specific? What fluid properties are probed at nanometric scales? In other words, why does 'nanofluidics' deserve its own brand name? In this critical review, we will explore the vast manifold of length scales emerging for fluid behavior at the nanoscale, as well as the associated mechanisms and corresponding applications. We will in particular explore the interplay between bulk and interface phenomena. The limit of validity of the continuum approaches will be discussed, as well as the numerous surface induced effects occurring at these scales, from hydrodynamic slippage to the various electro-kinetic phenomena originating from the couplings between hydrodynamics and electrostatics. An enlightening analogy between ion transport in nanochannels and transport in doped semi-conductors will be discussed (156 references).

  2. The role of thermophysics in the design, optimization and understanding of semiconductor crystal growth in space

    Science.gov (United States)

    Crouch, R. K.; Fripp, A. L.; Debnam, W. J.; Clark, I. O.

    1979-01-01

    The compound semiconductor material PbSnTe has been investigated by NASA Langley Research Center as part of the Material Processing in Space (MPS) experiment in the framework of the Space Shuttle program. The long-range goal of the research is the improving of the performance of infrared detectors for use in remote sensing experiments. Three distinct techniques will be used in the low-g environment of space: two techniques involving bulk growth from melt and a vapor growth technique. In order to establish realistic estimates of the required time for experiments and to determine the thermal gradients that will be required to avoid constitutional supercooling, the diffusion coefficients must be accurately measured, however more data especially in the vapor-solid phase relations are needed.

  3. III-V semiconductor materials and devices

    CERN Document Server

    Malik, R J

    1989-01-01

    The main emphasis of this volume is on III-V semiconductor epitaxial and bulk crystal growth techniques. Chapters are also included on material characterization and ion implantation. In order to put these growth techniques into perspective a thorough review of the physics and technology of III-V devices is presented. This is the first book of its kind to discuss the theory of the various crystal growth techniques in relation to their advantages and limitations for use in III-V semiconductor devices.

  4. Responsivity Calibration of Pyroelectric Terahertz Detectors

    CERN Document Server

    Berry, Christopher W; Jarrahi, Mona

    2014-01-01

    There has been a significant advancement in terahertz radiation sources in the past decade, making milliwatt terahertz power levels accessible in both continuous-wave and pulsed operation. Such high-power terahertz radiation sources circumvent the need for cryogenic-cooled terahertz detectors such as semiconductor bolometers and necessitate the need for new types of calibrated, room-temperature terahertz detectors. Among various types of room-temperature terahertz detectors, pyroelectric detectors are one of the most widely used detectors, which can offer wide dynamic range, broad detection bandwidth, and high sensitivity levels. In this article, we describe the calibration process of a commercially available pyroelectric detector (Spectrum Detector, Inc, SPI-A-65 THz), which incorporates a 5 mm diameter LiTaO3 detector with an organic terahertz absorber coating.

  5. Quantum processes in semiconductors

    CERN Document Server

    Ridley, B K

    2013-01-01

    Aimed at graduate students, this is a guide to quantum processes of importance in the physics and technology of semiconductors. The fifth edition includes new chapters that expand the coverage of semiconductor physics relevant to its accompanying technology.

  6. The ATLAS semiconductor tracker (SCT)

    CERN Document Server

    Jackson, J N

    2005-01-01

    The ATLAS detector (CERN/LHCC/94-43 (1994)) is designed to study a wide range of physics at the CERN Large Hadron Collider (LHC) at luminosities up to 10**3**4 cm**-**2 s**-**1 with a bunch-crossing rate of 40 MHz. The Semiconductor Tracker (SCT) forms a key component of the Inner Detector (vol. 1, ATLAS TDR 4, CERN/LHCC 97-16 (1997); vol. 2, ATLAS TDR 5, CERN/LHCC 97-17 (1997)) which is situated inside a 2 T solenoid field. The ATLAS Semiconductor Tracker (SCT) utilises 4088 silicon modules with binary readout mounted on carbon fibre composite structures arranged in the forms of barrels in the central region and discs in the forward region. The construction of the SCT is now well advanced. The design of the SCT modules, services and support structures will be briefly outlined. A description of the various stages in the construction process will be presented with examples of the performance achieved and the main difficulties encountered. Finally, the current status of the construction is reviewed.

  7. Handbook of spintronic semiconductors

    CERN Document Server

    Chen, Weimin

    2010-01-01

    Offers a review of the field of spintronic semiconductors. This book covers a range of topics, including growth and basic physical properties of diluted magnetic semiconductors based on II-VI, III-V and IV semiconductors, developments in theory and experimental techniques and potential device applications.

  8. Recent Advances in Optically Controlled Bulk Semiconductor Switches

    Science.gov (United States)

    1985-06-01

    REO!NT AIJifl,NCES IN (FTICALIX ~1Ra.LW IILK SHttiaHlOCIOR swrrams L. Bovino , T. Burke, R. Youmans, M. Weiner, J. Carter U.S. Ar~ Electronics...fabrication of all of our optically activated switches. B.e.fer.enc.es. 1. L. Bovino , R. Youmans, T. Burke, M.Weiner, "Modulator Circuits Using Q...tically Activated Switches", Record of 16th Power Modulator SYJll>o- siurn, pp 235-239, June 1984. 2. M. Weiner, T. Burke, R. Youmans, L. Bovino , J

  9. Printable semiconductor structures and related methods of making and assembling

    Science.gov (United States)

    Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne; Lee, Keon Jae; Khang; , Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao; Ko, Heung Cho; Mack, Shawn

    2013-03-12

    The present invention provides a high yield pathway for the fabrication, transfer and assembly of high quality printable semiconductor elements having selected physical dimensions, shapes, compositions and spatial orientations. The compositions and methods of the present invention provide high precision registered transfer and integration of arrays of microsized and/or nanosized semiconductor structures onto substrates, including large area substrates and/or flexible substrates. In addition, the present invention provides methods of making printable semiconductor elements from low cost bulk materials, such as bulk silicon wafers, and smart-materials processing strategies that enable a versatile and commercially attractive printing-based fabrication platform for making a broad range of functional semiconductor devices.

  10. Unitary lens semiconductor device

    Science.gov (United States)

    Lear, Kevin L.

    1997-01-01

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  11. New materials for radiation hard semiconductor dectectors

    Science.gov (United States)

    Sellin, P. J.; Vaitkus, J.

    2006-02-01

    We present a review of the current status of research into new semiconductor materials for use as particle tracking detectors in very high radiation environments. This work is carried out within the framework of the CERN RD50 collaboration, which is investigating detector technologies suitable for operation at the proposed super-LHC facility (SLHC). Tracking detectors operating at the SLHC in this environment will have to be capable of withstanding radiation levels arising from a luminosity of 10 35 cm -2 s -1 which will present severe challenges to current tracking detector technologies. The "new materials" activity within RD50 is investigating the performance of various semiconductor materials that potentially offer radiation hard alternatives to silicon devices. The main contenders in this study are silicon carbide, gallium nitride and amorphous silicon. In this paper we review the current status of these materials, in terms of material quality, commercial availability, charge transport properties, and radiation hardness studies. Whilst these materials currently show considerable promise for use as radiation hard tracking detectors, their ultimate success will depend on the continued improvement of the availability of high quality material.

  12. Sensitivity of a new-developed neutron detector

    Institute of Scientific and Technical Information of China (English)

    PENG Tai-Ping; ZHU Xue-Bin; YANG Hong-Qiong; YANG Jian-Lun; YANG Gao-Zhao; LI Lin-Bo; SONG Xian-Cai

    2005-01-01

    We develop a kind of neutron detector, which consists of a polyethylene thin film and two PIN semiconductors connected face-to-face. The detector is insensitive to γ-rays. Its sensitivity to neutron has been calculated with MCNP program and calibrated by experiments, and the results indicate that the neutron sensitivity of the compensation detector will vary with polyethylene converter. The compensation PIN detector can be employed to measure pulse neutron in neutron and gamma mixture radiation field.

  13. AlN Based Extreme Ultraviolet (EUV) Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I project is to investigate the feasibility for achieving EUV detectors for space applications by exploiting the ultrahigh bandgap semiconductor - AlN. We...

  14. Gain dynamics and saturation in semiconductor quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper; Hvam, Jørn Märcher

    2004-01-01

    Quantum dot (QD)-based semiconductor optical amplifiers offer unique properties compared with conventional devices based on bulk or quantum well material. Due to the bandfilling properties of QDs and the existence of a nearby reservoir of carriers in the form of a wetting layer, QD semiconductor...... carrier populations in terms of a simple rate equation model. Based on the steady-state and small-signal properties of the model, we analyse and discuss the optical modulation response and the four-wave mixing properties of QD semiconductor optical amplifiers, in particular emphasizing the role...

  15. The k p Method Electronic Properties of Semiconductors

    CERN Document Server

    Willatzen, Morten

    2009-01-01

    This book presents a detailed exposition of the formalism and application of k.p theory for both bulk and nanostructured semiconductors. For bulk crystals, this is the first time all the major techniques for deriving the most popular Hamiltonians have been provided in one place. For nanostructures, this is the first time the Burt-Foreman theory has been made accessible. Thus, the reader will gain a clear understanding of the k.p method, will have an explicit listing of the various Hamiltonians in a consistent notation for their use, and a set of representative results. In addition, the reader can derive an excellent understanding of the electronic structure of semiconductors.

  16. Density Functional Modelling of Elastic Properties of Elemental Semiconductors

    Directory of Open Access Journals (Sweden)

    M. Verma

    2011-01-01

    Full Text Available The expressions for bulk modulus, its first and second pressure derivatives for elemental semiconductors are derived using the ab initio pseudopotential approach to the total crystal energy within the framework of local Density Functional formalism. The expression for the second pressure derivative of the bulk modulus for four-fold crystal structures are derived for the first time within the pseudopotential framework. The computed results for the semiconductors under study are very close to the available experimental data and will be useful in the study of equation of states.

  17. A simulation study on the focal plane detector of the LAUE project

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M., E-mail: mkhalil@in2p3.fr [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy); Frontera, F. [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy); INAF/IASF-Bologna, Via P. Gobetti 101, Bologna (Italy); Caroli, E. [INAF/IASF-Bologna, Via P. Gobetti 101, Bologna (Italy); Virgilli, E.; Valsan, V. [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy)

    2015-06-21

    The LAUE project, supported by the Italian Space Agency (ASI), is devoted to the development of a long focal length (even 20 m or longer) Laue lens for gamma ray astronomy between 80 and 600 keV. These lenses take advantage of Bragg diffraction to focus radiation onto a small spot drastically improving the signal to noise ratio as well as reducing the required size of the detector significantly. In this paper we present a Monte-Carlo simulation study with MEGALIB to optimize, for space applications, the detector size to achieve high detection efficiency, and to optimize the position resolution of the detector to reconstruct the Point Spread Function of the lens considered for the LAUE project. Then we will show simulations, using the SILVACO semiconductor simulation toolkit, on the optimized detector to estimate its capacitance per channel and depletion voltage. In all of the simulations, two materials were compared; a low density material (Silicon) and a high density material (Germanium). - Highlights: • The quantized Hall plateaus and Shubnikov de Haas oscillations in transition metal doped topological insulators are observed. • The evidence of a two-dimensional/layered transport of the bulk electrons is reported. • An obvious ferromagnetism in doped topological insulators is observed. • Care should be taken to pindown the transport of the topological SS in topological insulators.

  18. Semiconductor Physical Electronics

    CERN Document Server

    Li, Sheng

    2006-01-01

    Semiconductor Physical Electronics, Second Edition, provides comprehensive coverage of fundamental semiconductor physics that is essential to an understanding of the physical and operational principles of a wide variety of semiconductor electronic and optoelectronic devices. This text presents a unified and balanced treatment of the physics, characterization, and applications of semiconductor materials and devices for physicists and material scientists who need further exposure to semiconductor and photonic devices, and for device engineers who need additional background on the underlying physical principles. This updated and revised second edition reflects advances in semicondutor technologies over the past decade, including many new semiconductor devices that have emerged and entered into the marketplace. It is suitable for graduate students in electrical engineering, materials science, physics, and chemical engineering, and as a general reference for processing and device engineers working in the semicondi...

  19. Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors

    Science.gov (United States)

    Hung, Nguyen T.; Hasdeo, Eddwi H.; Nugraha, Ahmad R. T.; Dresselhaus, Mildred S.; Saito, Riichiro

    2016-07-01

    We theoretically investigate the interplay between the confinement length L and the thermal de Broglie wavelength Λ to optimize the thermoelectric power factor of semiconducting materials. An analytical formula for the power factor is derived based on the one-band model assuming nondegenerate semiconductors to describe quantum effects on the power factor of the low-dimensional semiconductors. The power factor is enhanced for one- and two-dimensional semiconductors when L is smaller than Λ of the semiconductors. In this case, the low-dimensional semiconductors having L smaller than their Λ will give a better thermoelectric performance compared to their bulk counterpart. On the other hand, when L is larger than Λ , bulk semiconductors may give a higher power factor compared to the lower dimensional ones.

  20. Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors.

    Science.gov (United States)

    Hung, Nguyen T; Hasdeo, Eddwi H; Nugraha, Ahmad R T; Dresselhaus, Mildred S; Saito, Riichiro

    2016-07-15

    We theoretically investigate the interplay between the confinement length L and the thermal de Broglie wavelength Λ to optimize the thermoelectric power factor of semiconducting materials. An analytical formula for the power factor is derived based on the one-band model assuming nondegenerate semiconductors to describe quantum effects on the power factor of the low-dimensional semiconductors. The power factor is enhanced for one- and two-dimensional semiconductors when L is smaller than Λ of the semiconductors. In this case, the low-dimensional semiconductors having L smaller than their Λ will give a better thermoelectric performance compared to their bulk counterpart. On the other hand, when L is larger than Λ, bulk semiconductors may give a higher power factor compared to the lower dimensional ones.

  1. A 65 nm CMOS broadband self-calibrated power detector for the square kilometre array radio telescope

    Directory of Open Access Journals (Sweden)

    Ge Wu

    2014-08-01

    Full Text Available In this study, a 65 nm complementary metal oxide semiconductor (CMOS broadband self-calibrated high-sensitivity power detector for use in the Square Kilometre Array (SKA, the next-generation high-sensitivity radio telescope, is presented. The power detector calibration is performed by adjusting voltages at the bulk terminals of the input transistors to compensate for mismatches in the output voltages because of process, voltage and temperature variations. Measurements show that the power detector, preceded by an input power-match circuit with 6 dB gain, has an input signal range from −48 to −11 dBm over which a 0.95 dB maximum error in the detected power is observed when the calibration rate is 20 kHz. The proposed broadband power detector has a 3 dB upper band edge of 1.8 GHz, which adequately covers the midband SKA frequency range from 0.7 to 1.4 GHz. The settling time and the calibration time are both <5 μs. The circuit consumes 1.2 mW from a 1.2 V power supply and the input-match circuit consumes another 5.8 mW. The presented power detector achieves the best combination of the detection range and sensitivity of previously published circuits.

  2. Impact of metal overhang and guard ring techniques on breakdown voltage of Si strip sensors - 2003 IEEE nuclear science symposium, medical imaging conference, and workshop of room-temperature semiconductor detectors

    CERN Document Server

    Ranjan, K; Namrata, S; Chatterji, S; Srivastava-Ajay, K; Kumar, A; Jha, Manoj Kumar; Shivpuri, R K

    2004-01-01

    The importance of Si sensors in high-energy physics (HEP) experiments can hardly be overemphasized. However, the high luminosity and the high radiation level in the future HEP experiments, like Large Hadron Collider (LHC), has posed a serious challenge to the fabrication of Si detectors. For the safe operation over the full LHC lifetime, detectors are required to sustain very high voltage operation, well exceeding the bias voltage needed to full deplete the heavily irradiated Si sensors. Thus, the main effort in the development of Si sensors is concentrated on a design that avoids p-n junction breakdown at operational biases. Among various proposed techniques, Field-limiting Ring (FLR) (or guard ring) and Metal-Overhang (MO) are technologically simple and are suitable for vertical devices. Since high-voltage planar Si junctions are of great importance in the HEP experiments, it is very interesting to compare these two aforementioned techniques for achieving the maximum breakdown voltage under optimal conditio...

  3. Enhancement of superconducting critical current by injection of quasiparticles in superconductor semiconductor devices

    DEFF Research Database (Denmark)

    Kutchinsky, Jonatan; Taboryski, Rafael Jozef; Sørensen, C. B.

    2000-01-01

    We report new measurements on 3-terminal superconductor semiconductor injection devices, demonstrating enhancement of the supercurrent by injection from a superconducting injector electrode. Two other electrodes were used as detectors. Applying a small voltage to the injector, reduced the maximum...

  4. Infrared Semiconductor Metamaterials

    Science.gov (United States)

    2016-09-01

    AFRL-AFOSR-VA-TR-2016-0310 Infrared Semiconductor Metamaterials Jon Schuller UNIVERSITY OF CALIFORNIA SANTA BARBARA 3227 CHEADLE HL SANTA BARBARA, CA...From - To) 15-07-2013 to 14-07-2016 4. TITLE AND SUBTITLE Infrared Semiconductor Metamaterials 5a. CONTRACT NUMBER FA9550-13-1-0182 5b. GRANT...program are 1) establishing an approach for widely tunable resonators and metasurfaces 2) experimentally demonstrating widely tunable semiconductor

  5. Development of semiconductor radiation sensors for portable alarm-dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Moon, B. S.; Chung, C. E.; Hong, S. B.; Kim, J. Y.; Kim, J. B.; Han, S. H.; Lee, W. G. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-01-01

    We studied Semiconductor Radiation Sensors for Portable Alarm-Dosimeter. We calculated response functions for gamma energy 0.021, 0.122, 0.662, 0.835, 1.2 MeV using EGS4 codes. When we measured at various distance from source to detector, the detection efficiency of Si semiconductor detector was better than that of GM tube. The linear absorption coefficients of steel and aluminum plate were measured. These experimental results of the response of detector for intensity of radiation field coincide to the theoretical expectation. The count value of Si detector was changed with changing thickness of steel as changing threshold voltage of discriminator, and the linear absorption coefficient increased with increasing threshold voltage. Radiation detection efficiency shows difference at each threshold voltage condition. This results coincided to the theoretical simulation. 33 refs., 27 figs., 8 tabs. (Author)

  6. Operation and performance of the ATLAS semiconductor tracker

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahmadov, Faig; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernabéu, José; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boutouil, Sara; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Branchini, Paolo; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Gareth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bundock, Aaron Colin; Burckhart, Helfried; Burdin, Sergey; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavaliere, Viviana; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerio, Benjamin; Cerny, Karel; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Kevin; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Charfeddine, Driss; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Liming; Chen, Shenjian; Chen, Xin; Chen, Yujiao; Cheng, Hok Chuen; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiefari, Giovanni; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christidi, Ilektra-Athanasia; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocio, Alessandra; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collins-Tooth, Christopher; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Connell, Simon Henry; Connelly, Ian; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Daniells, Andrew Christopher; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; De Zorzi, Guido; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Degenhardt, James; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Domenico, Antonio; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; do Vale, Maria Aline Barros; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobos, Daniel; Dobson, Ellie; Doglioni, Caterina; Doherty, Tom; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dova, Maria-Teresa; Doyle, Tony; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Dubreuil, Emmanuelle; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Dwuznik, Michal; Dyndal, Mateusz; Ebke, Johannes; Edson, William; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Engelmann, Roderich; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Favareto, Andrea; Fayard, Louis; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Fernandez Perez, Sonia; Ferrag, Samir; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Julia; Fisher, Wade Cameron; Fitzgerald, Eric Andrew; Flechl, Martin; Fleck, Ivor; Fleischmann, Philipp; Fleischmann, Sebastian; Fletcher, Gareth Thomas; Fletcher, Gregory; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Florez Bustos, Andres Carlos; Flowerdew, Michael; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gandrajula, Reddy Pratap; Gao, Jun; Gao, Yongsheng; Garay Walls, Francisca; Garberson, Ford; García, Carmen; Garcia Argos, Carlos; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giangiobbe, Vincent; Giannetti, Paola; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Stephen; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giugni, Danilo; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkialas, Ioannis; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Glonti, George; Goblirsch-Kolb, Maximilian; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goeringer, Christian; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodrick, Maurice; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabas, Herve Marie Xavier; Graber, Lars; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Grebenyuk, Oleg; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grohs, Johannes Philipp; Grohsjean, Alexander; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Groth-Jensen, Jacob; Grout, Zara Jane; Grybel, Kai; Guan, Liang; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guicheney, Christophe; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Gunther, Jaroslav; Guo, Jun; Gupta, Shaun; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guttman, Nir; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageboeck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Hall, David; Halladjian, Garabed; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Hanke, Paul; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Satoshi; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Heisterkamp, Simon; Hejbal, Jiri; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Hengler, Christopher; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hofmann, Julia Isabell; Hohlfeld, Marc; Holmes, Tova Ray; Hong, Tae Min; Hooft van Huysduynen, Loek; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Ideal, Emma; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Inamaru, Yuki; Ince, Tayfun; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Ivarsson, Jenny; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanty, Laura; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Erik; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joseph, John; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Karnevskiy, Mikhail; Karpov, Sergey; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katre, Akshay; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Keller, John; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hee Yeun; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Klok, Peter; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; König, Sebastian; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubik, Petr; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kurumida, Rie; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; La Rosa, Alessandro; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laier, Heiko; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Le, Bao Tran; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire, Alexandra; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzen, Georg; Lenzi, Bruno; Leone, Robert; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lester, Christopher; Lester, Christopher Michael; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Liang; Li, Shu; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Brian Alexander; Long, Jonathan; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lungwitz, Matthias; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeno, Mayuko; Maeno, Tadashi; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marques, Carlos; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian; Martin, Jean-Pierre; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Homero; Martinez, Mario; Martin-Haugh, Stewart; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mättig, Peter; Mättig, Stefan; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Meric, Nicolas; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Moeller, Victoria; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Klemens; Mueller, Thibaut; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Nanava, Gizo; Narayan, Rohin; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Ohshima, Takayoshi; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pearce, James; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petteni, Michele; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piegaia, Ricardo; Pieron, Jacek Piotr; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pingel, Almut; Pinto, Belmiro; Pires, Sylvestre; Pitt, Michael; Pizio, Caterina; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Poddar, Sahill; Podlyski, Fabrice; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Przysiezniak, Helenka; Ptacek, Elizabeth; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quarrie, David; Quayle, William; Quilty, Donnchadha; Qureshi, Anum; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Randle-Conde, Aidan Sean; Rangel-Smith, Camila; Rao, Kanury; Rauscher, Felix; Rave, Tobias Christian; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reinsch, Andreas; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Ridel, Melissa; Rieck, Patrick; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodrigues, Luis; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Matthew; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sacerdoti, Sabrina; Saddique, Asif; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Savard, Pierre; Savu, Dan Octavian; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R. Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Christopher; Schmitt, Sebastian; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scott, Bill; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellers, Graham; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Seuster, Rolf; Severini, Horst; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Rick; Sherwood, Peter; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snow, Joel; Snyder, Scott; Sobie, Randall; Socher, Felix; Sodomka, Jaromir; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopczak, Andre; Sopko, Vit; Sopko, Bruno; Sorin, Veronica; Sosebee, Mark; Soualah, Rachik; Soueid, Paul; Soukharev, Andrey; South, David; Spagnolo, Stefania; Spanò, Francesco; Spearman, William Robert; Spighi, Roberto; Spigo, Giancarlo; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Staerz, Steffen; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Stavina, Pavel; Steele, Genevieve; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramania, Halasya Siva; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Svatos, Michal; Swedish, Stephen; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Tran, Huong Lan; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Uhlenbrock, Mathias; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Virzi, Joseph; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Wolfgang; Wagner, Peter; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chao; Wang, Chiho; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warren, Matthew; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wilson, Alan; Wingerter-Seez, Isabelle; Winklmeier, Frank; Wittgen, Matthias; Wittig, Tobias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wright, Michael; Wu, Mengqing; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Un-Ki; Yang, Yi; Yanush, Serguei; Yao, Liwen; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yen, Andy L; Yildirim, Eda; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Lei; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Lei; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Zinonos, Zinonas; Ziolkowski, Michael; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zutshi, Vishnu; Zwalinski, Lukasz

    2014-01-01

    The semiconductor tracker is a silicon microstrip detector forming part of the inner tracking system of the ATLAS experiment at the LHC. The operation and performance of the semiconductor tracker during the first years of LHC running are described. More than 99% of the detector modules were operational during this period, with an average intrinsic hit efficiency of (99.74 +/- 0.04)%. The evolution of the noise occupancy is discussed, and measurements of the Lorentz angle, delta-ray production and energy loss presented. The alignment of the detector is found to be stable at the few-micron level over long periods of time. Radiation damage measurements, which include the evolution of detector leakage currents, are found to be consistent with predictions and are used in the verification of radiation background simulations.

  7. Semiconductor bridge (SCB) detonator

    Science.gov (United States)

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  8. Semiconductor Electrical Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Electrical Measurements Laboratory is a research laboratory which complements the Optical Measurements Laboratory. The laboratory provides for Hall...

  9. Investigation of Surface Breakdown on Semiconductor Devices Using Optical Probing Techniques.

    Science.gov (United States)

    1990-01-01

    18] L. Bovino , T. Burke, R. Youmans, M. Weiner, and J. Car, r, "Recent Advances in Optically C’ntrolled Bulk Semiconductor Switches," Digest of...Comp. Simul. 5 (3), 175 (1988). [321 M. Weiner, L. Bovino , R. Youmans, and T. Burke, "Modeling of the Optically Conrolled Semiconductor Switch," J

  10. Large area bulk superconductors

    Science.gov (United States)

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  11. Semiconductor Research Experimental Techniques

    CERN Document Server

    Balkan, Naci

    2012-01-01

    The book describes the fundamentals, latest developments and use of key experimental techniques for semiconductor research. It explains the application potential of various analytical methods and discusses the opportunities to apply particular analytical techniques to study novel semiconductor compounds, such as dilute nitride alloys. The emphasis is on the technique rather than on the particular system studied.

  12. Semiconductors data handbook

    CERN Document Server

    Madelung, Otfried

    2004-01-01

    This volume Semiconductors: Data Handbook contains frequently used data from the corresponding larger Landolt-Börnstein handbooks in a low price book for the individual scientist working in the laboratory. The Handbook contain important information about a large number of semiconductors

  13. Applications of Semiconductor Lasers

    Institute of Scientific and Technical Information of China (English)

    LI Te; SUN Yan-fang; NING Yong-qiang; WANG Li-jun

    2005-01-01

    An overview of the applications of semiconductor lasers is presented. Diode lasers are widely used today,and the most prevalent use of the laser is probably in CD and DVD drives for computers and audio/video media systems. Semiconductor lasers are also used in many other fields ranging from optical fiber communications to display,medicine and pumping sources.

  14. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  15. The AlGaAs light emitting particle detector

    CERN Document Server

    Pozela, J; Silenas, A; Juciene, V; Dapkus, L; Jasutis, V; Tamulaitis, G; Zukauskas, A; Bendorius, R A

    1999-01-01

    An AlGaAs light emitting particle detector was fabricated and investigated experimentally. Light emitting semiconductor Al sub x Ga sub 1 sub - sub x As layers with graded-gap energy band structure were grown, and luminescence spectra were investigated. A light emitting X-ray detector was also fabricated. (author)

  16. Study on Signal Processing Circuit Based on Scintillation Detector

    Institute of Scientific and Technical Information of China (English)

    YAO; Yong-gang; DENG; Chang-ming; LI; Jian-wei; XIAO; Cai-jin; ZHANG; Gui-ying; WANG; Ping-sheng; WANG; Xing-hua; JIN; Xiang-chun; HUA; Long; YUAN; Guo-jun; NI; Bang-fa

    2013-01-01

    Compared with silicon semiconductor detector,higher energy resolution and together with the high detection efficiency,big sensitive volume,good adaptability to environment and high sensitivityespecially in nature background environment are the characteristics of scintillation detector.The most widely applied scintillator includes inorganic crystals,of which sodium iodide is the favorite and

  17. Fabrication of Superconducting Detectors for Studying the Universe

    Science.gov (United States)

    Brown, Ari-David

    2012-01-01

    Superconducting detectors offer unparalleled means of making astronomical/cosmological observations. Fabrication of these detectors is somewhat unconventional; however, a lot of novel condensed matter physics/materials scientific discoveries and semiconductor fabrication processes can be generated in making these devices.

  18. Development of an infrared detector: Quantum well infrared photodetector

    Institute of Scientific and Technical Information of China (English)

    LU Wei; LI Ling; ZHENG HongLou; XU WenLan; XIONG DaYuan

    2009-01-01

    The progress in the quantum well infrared photo-detector (QWIP) based on quantum confinement in semiconductor in recent 10 years has been reviewed. The differences between QWlP and the HgCdTe (HCT) infrared detector as well as their compensation are analyzed. The outlook for near-future trends in QWIP technologies is also presented.

  19. Development of an infrared detector: Quantum well infrared photodetector

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The progress in the quantum well infrared photo-detector (QWIP) based on quantum confinement in semiconductor in recent 10 years has been reviewed. The differences between QWIP and the HgCdTe (HCT) infrared detector as well as their compensation are analyzed. The outlook for near-future trends in QWIP technologies is also presented.

  20. Terahertz semiconductor nonlinear optics

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias

    2013-01-01

    In this proceedings we describe our recent results on semiconductor nonlinear optics, investigated using single-cycle THz pulses. We demonstrate the nonlinear absorption and self-phase modulation of strong-field THz pulses in doped semiconductors, using n-GaAs as a model system. The THz...... nonlinearity in doped semiconductors originates from the near-instantaneous heating of free electrons in the ponderomotive potential created by electric field of the THz pulse, leading to ultrafast increase of electron effective mass by intervalley scattering. Modification of effective mass in turn leads...... to a decrease of plasma frequency in semiconductor and produces a substantial modification of THz-range material dielectric function, described by the Drude model. As a result, the nonlinearity of both absorption coefficient and refractive index of the semiconductor is observed. In particular we demonstrate...

  1. Fabrication of TlBr Detector

    Institute of Scientific and Technical Information of China (English)

    HAO; Xiao-yong

    2015-01-01

    1 Introduction Thallium bromide(TlBr)is an attractive compound semiconductor material for fabrication of room temperature radiation detectors due to its characteristics of wide band-gap energy,high density,high atomic numbers.It can be used in the fields of security detection,imaging and radiation protection.

  2. Photon detector configured to employ the Gunn effect and method of use

    Science.gov (United States)

    Cich, Michael J

    2015-03-17

    Embodiments disclosed herein relate to photon detectors configured to employ the Gunn effect for detecting high-energy photons (e.g., x-rays and gamma rays) and methods of use. In an embodiment, a photon detector for detecting high-energy photons is disclosed. The photon detector includes a p-i-n semiconductor diode having a p-type semiconductor region, an n-type semiconductor region, and a compensated i-region disposed between the p-type semiconductor region and the n-type semiconductor region. The compensated i-region and has a width of about 100 .mu.m to about 400 .mu.m and is configured to exhibit the Gunn effect when the p-i-n semiconductor diode is forward biased a sufficient amount. The compensated i-region is doped to include a free carrier concentration of less than about 10.sup.10 cm.sup.-3.

  3. Photoacoustic characterization of n-RuSe2 semiconductor pellets

    Science.gov (United States)

    Bernal-Alvarado, J.; Vargas-Luna, M.; Solorza-Feria, O.; Mondragón, R.; Alonso-Vante, N.

    2000-09-01

    Using the open photoacoustic cell technique, a set of physical properties for a semiconductor (n-RuSe2) in powder form was measured. According to the Dramicanin theoretical model, charge carriers transport parameters (bulk and surface) and the effective thermal diffusivity were obtained.

  4. Handbook of compound semiconductors growth, processing, characterization, and devices

    CERN Document Server

    Holloway, Paul H

    1996-01-01

    This book reviews the recent advances and current technologies used to produce microelectronic and optoelectronic devices from compound semiconductors. It provides a complete overview of the technologies necessary to grow bulk single-crystal substrates, grow hetero-or homoepitaxial films, and process advanced devices such as HBT's, QW diode lasers, etc.

  5. Imaging detectors and electronics - A view of the future

    Energy Technology Data Exchange (ETDEWEB)

    Spieler, Helmuth

    2004-06-16

    Imaging sensors and readout electronics have made tremendous strides in the past two decades. The application of modern semiconductor fabrication techniques and the introduction of customized monolithic integrated circuits have made large scale imaging systems routine in high energy physics. This technology is now finding its way into other areas, such as space missions, synchrotron light sources, and medical imaging. I review current developments and discuss the promise and limits of new technologies. Several detector systems are described as examples of future trends. The discussion emphasizes semiconductor detector systems, but I also include recent developments for large-scale superconducting detector arrays.

  6. Development, prototyping and characterization of double sided silicon strip detectors

    Science.gov (United States)

    Topkar, Anita; Singh, Arvind; Aggarwal, Bharti; Kumar, Amit; Kumar, Arvind; Murali Krishna, L. V.; Das, D.

    2016-10-01

    Double sided DC-coupled silicon strip detectors with geometry of 65 mm×65 mm have been developed in India for nuclear physics experiments. The detectors have 64 P+ strips on the front side and 64 N+ strips on the backside with a pitch of 0.9 mm. These detectors were fabricated using a twelve mask layer process involving double sided wafer processing technology. Semiconductor process and device simulations were carried out in order to theoretically estimate the impact of important design and process parameters on the breakdown voltage of detectors. The performance of the first lot of prototype detectors has been studied using static characterization tests and using an alpha source. The characterization results demonstrate that the detectors have low leakage currents and good uniformity over the detector area of about 40 cm2. Overview of the detector design, fabrication process, simulation results and initial characterization results of the detectors are presented in this paper.

  7. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  8. Metal Detectors.

    Science.gov (United States)

    Harrington-Lueker, Donna

    1992-01-01

    Schools that count on metal detectors to stem the flow of weapons into the schools create a false sense of security. Recommendations include investing in personnel rather than hardware, cultivating the confidence of law-abiding students, and enforcing discipline. Metal detectors can be quite effective at afterschool events. (MLF)

  9. Semiconductor nanowire optical antenna solar absorbers.

    Science.gov (United States)

    Cao, Linyou; Fan, Pengyu; Vasudev, Alok P; White, Justin S; Yu, Zongfu; Cai, Wenshan; Schuller, Jon A; Fan, Shanhui; Brongersma, Mark L

    2010-02-10

    Photovoltaic (PV) cells can serve as a virtually unlimited clean source of energy by converting sunlight into electrical power. Their importance is reflected in the tireless efforts that have been devoted to improving the electrical and structural properties of PV materials. More recently, photon management (PM) has emerged as a powerful additional means to boost energy conversion efficiencies. Here, we demonstrate an entirely new PM strategy that capitalizes on strong broad band optical antenna effects in one-dimensional semiconductor nanostructures to dramatically enhance absorption of sunlight. We show that the absorption of sunlight in Si nanowires (Si NWs) can be significantly enhanced over the bulk. The NW's optical properties also naturally give rise to an improved angular response. We propose that by patterning the silicon layer in a thin film PV cell into an array of NWs, one can boost the absorption for solar radiation by 25% while utilizing less than half of the semiconductor material (250% increase in the light absorption per unit volume of material). These results significantly advance our understanding of the way sunlight is absorbed by one-dimensional semiconductor nanostructures and provide a clear, intuitive guidance for the design of efficient NW solar cells. The presented approach is universal to any semiconductor and a wide range of nanostructures; as such, it provides a new PV platform technology.

  10. First tests of "bulk" MICROMEGAS with resistive cathode mesh

    CERN Document Server

    Olivera, R; Pietropaolo, F; Picchi, P

    2010-01-01

    We present the first results from tests of a MICROMEGAS detector manufactured using the so-called "bulk" technology and having a resistive cathode mesh instead of the conventional metallic one. This detector operates as usual MICROMEGAS, but in the case of sparks, which may appear at high gas gains, the resistive mesh reduces their current and makes the sparks harmless. This approach could be complementary to the ongoing efforts of various groups to develop spark-protected MICROMEGAS with resistive anode planes.

  11. 18th International Workshop on Radiation Imaging Detectors

    CERN Document Server

    2016-01-01

    The International Workshops on Radiation Imaging Detectors are held yearly and provide an international forum for discussing current research and developments in the area of position sensitive detectors for radiation imaging, including semiconductor detectors, gas and scintillator-based detectors. Topics include processing and characterization of detector materials, hybridization and interconnect technologies, design of counting or integrating electronics, readout and data acquisition systems, and applications in various scientific and industrial fields. The workshop will have plenary sessions with invited and contributed papers presented orally and in poster sessions. The invited talks will be chosen to review recent advances in different areas covered in the workshop.

  12. Semiconductors bonds and bands

    CERN Document Server

    Ferry, David K

    2013-01-01

    As we settle into this second decade of the twenty-first century, it is evident that the advances in micro-electronics have truly revolutionized our day-to-day lifestyle. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors. It describes how quantum mechanics gives semiconductors unique properties that enabled the micro-electronics revolution, and sustain the ever-growing importance of this revolution.

  13. Physics of semiconductor lasers

    CERN Document Server

    Mroziewicz, B; Nakwaski, W

    2013-01-01

    Written for readers who have some background in solid state physics but do not necessarily possess any knowledge of semiconductor lasers, this book provides a comprehensive and concise account of fundamental semiconductor laser physics, technology and properties. The principles of operation of these lasers are therefore discussed in detail with the interrelations between their design and optical, electrical and thermal properties. The relative merits of a large number of laser structures and their parameters are described to acquaint the reader with the various aspects of the semiconductor l

  14. Defects in semiconductors

    CERN Document Server

    Romano, Lucia; Jagadish, Chennupati

    2015-01-01

    This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

  15. Coherent dynamics in semiconductors

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    1998-01-01

    Ultrafast nonlinear optical spectroscopy is used to study the coherent dynamics of optically excited electron-hole pairs in semiconductors. Coulomb interaction implies that the optical inter-band transitions are dominated, at least at low temperatures, by excitonic effects. They are further...... and molecular systems are found and studied in the exciton-biexciton system of semiconductors. At densities where strong exciton interactions, or many-body effects, become dominant, the semiconductor Bloch equations present a more rigorous treatment of the phenomena Ultrafast degenerate four-wave mixing is used...

  16. Spin splitting in 2D monochalcogenide semiconductors

    Science.gov (United States)

    Do, Dat T.; Mahanti, Subhendra D.; Lai, Chih Wei

    2015-11-01

    We report ab initio calculations of the spin splitting of the uppermost valence band (UVB) and the lowermost conduction band (LCB) in bulk and atomically thin GaS, GaSe, GaTe, and InSe. These layered monochalcogenides appear in four major polytypes depending on the stacking order, except for the monoclinic GaTe. Bulk and few-layer ε-and γ -type, and odd-number β-type GaS, GaSe, and InSe crystals are noncentrosymmetric. The spin splittings of the UVB and the LCB near the Γ-point in the Brillouin zone are finite, but still smaller than those in a zinc-blende semiconductor such as GaAs. On the other hand, the spin splitting is zero in centrosymmetric bulk and even-number few-layer β-type GaS, GaSe, and InSe, owing to the constraint of spatial inversion symmetry. By contrast, GaTe exhibits zero spin splitting because it is centrosymmetric down to a single layer. In these monochalcogenide semiconductors, the separation of the non-degenerate conduction and valence bands from adjacent bands results in the suppression of Elliot-Yafet spin relaxation mechanism. Therefore, the electron- and hole-spin relaxation times in these systems with zero or minimal spin splittings are expected to exceed those in GaAs when the D’yakonov-Perel’ spin relaxation mechanism is also suppressed.

  17. Irradiation tests of double-sided silicon strip detectors with a special guard ring structure

    Energy Technology Data Exchange (ETDEWEB)

    Abt, I. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Andricek, L. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Bauer, C. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Baumann, I. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Fox, H. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Halley, A. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Knoepfle, K.T. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Kroha, H. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Richter, R.H. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Riechmann, K. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Rietz, M. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Ruebsam, R. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Seywerd, H. [Max-Planck-Institut fuer Physik, Muenchen (Germany); St Denis, R. [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    1995-12-01

    The results of the first irradiation tests of newly designed silicon microstrip detectors performed with 21 MeV protons at the Max-Planck-Institut in Heidelberg are presented. The detectors were developed and produced by the semiconductor laboratory of the Max-Planck-Institut in Munich. Novel guard ring structures allow operation of the detectors at voltages exceeding 300 V. (orig.)

  18. Special Issue featuring invited articles arising from UK Semiconductors 2012

    Science.gov (United States)

    Clarke, Edmund; Wada, Osamu

    2013-07-01

    Semiconductor research has formed the basis of many technological advances over the past 50 years, and the field is still highly active, as new material systems and device concepts are developed to address new applications or operating conditions. In addition to the development of traditional semiconductor devices, the wealth of experience with these materials also allows their use as an ideal environment for testing new physics, leading to new classes of devices exploiting quantum mechanical effects that can also benefit from the advantages of existing semiconductor technology in scalability, compactness and ease of mass production. This special issue features papers arising from the UK Semiconductors 2012 Conference, held at the University of Sheffield. The annual conference covers all aspects of semiconductor research, from crystal growth, through investigations of the physics of semiconductor structures to realization of semiconductor devices and their application in emerging technologies. The 2012 conference featured over 150 presentations, including plenary sessions on interband cascade lasers for the 3-6 µm spectral band, efficient single photon sources based on InAs quantum dots embedded in GaAs photonic nanowires, nitride-based quantum dot visible lasers and single photon sources, and engineering of organic light-emitting diodes. The seven papers collected here highlight current research advances, taken from across the scope of the conference. The papers feature growth of novel nitride-antimonide material systems for mid-infrared sources and detectors, use of semiconductor nanostructures for charge-based memory and visible lasers, optimization of device structures either to reduce losses in solar cells or achieve low noise amplification in transistors, design considerations for surface-emitting lasers incorporating photonic crystals and an assessment of laser power convertors for power transfer. The editors of this special issue and the conference

  19. Spectroscopy of organic semiconductors from first principles

    Science.gov (United States)

    Sharifzadeh, Sahar; Biller, Ariel; Kronik, Leeor; Neaton, Jeffery

    2011-03-01

    Advances in organic optoelectronic materials rely on an accurate understanding their spectroscopy, motivating the development of predictive theoretical methods that accurately describe the excited states of organic semiconductors. In this work, we use density functional theory and many-body perturbation theory (GW/BSE) to compute the electronic and optical properties of two well-studied organic semiconductors, pentacene and PTCDA. We carefully compare our calculations of the bulk density of states with available photoemission spectra, accounting for the role of finite temperature and surface effects in experiment, and examining the influence of our main approximations -- e.g. the GW starting point and the application of the generalized plasmon-pole model -- on the predicted electronic structure. Moreover, our predictions for the nature of the exciton and its binding energy are discussed and compared against optical absorption data. We acknowledge DOE, NSF, and BASF for financial support and NERSC for computational resources.

  20. Enhanced photoredox chemistry in quantized semiconductor colloids

    Energy Technology Data Exchange (ETDEWEB)

    Nedeljkovic, J.M.; Nenadovic, M.T.; Micic, O.I.; Nozik, A.J.

    1986-01-02

    Optical effects due to size quantization have been observed for HgSe, PbSe, and CdSe colloids in water and acetonitrile with particle diameters of 20-100 A. For diameters less than 50 A, the optical absorption edge of HgSe and PbSe is blue shifted by several volts. The results are consistent with perturbation of the semiconductor band structure due to carrier confinement in very small particles resulting in an increase in the effective band gap. The redox potential of photogenerated carriers is greatly enhanced in such quantized semiconductor particles; reduction reactions that cannot occur in bulk materials can occur in sufficiently small particles. This has been demonstrated with H/sub 2/ evolution in 50-A PbSe and HgSe colloids and CO/sub 2/ reduction in 50-A CdSe colloids. 13 references, 3 figures.

  1. 2012 DEFECTS IN SEMICONDUCTORS GORDON RESEARCH CONFERENCE, AUGUST 12-17, 2012

    Energy Technology Data Exchange (ETDEWEB)

    GLASER, EVAN

    2012-08-17

    The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

  2. 2012 Gordon Research Conference on Defects in Semiconductors - Formal Schedule and Speaker/Poster Program

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Evan [Naval Research Lab. (NRL), Washington, DC (United States)

    2012-08-17

    The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

  3. Analysis of trapping and de-trapping in CdZnTe detectors by Pockels effect

    Science.gov (United States)

    Rejhon, M.; Franc, J.; Dědič, V.; Kunc, J.; Grill, R.

    2016-09-01

    In this contribution we introduce a method of deep level spectroscopy in semi-insulating semiconductors demonstrated on detector-grade bulk CdZnTe. The method is based on the measurements of temporal and temperature evolution of the electric field profile in studied samples, which is very sensitive to a change of occupancy of deep levels. The measurement of the electric field is based on the linear electro-optic (Pockels) effect using the InGaAs avalanche photodiode with fast response. The internal electric field profile in studied samples significantly changes under various external conditions represented by the application of the bias and pulsed illumination with below-bandgap light. From the knowledge of the electric field behavior and using a standard analysis based on thermally induced transitions of electrons and holes from the deep levels to the conduction and valence bands, respectively, it is possible to get activation energies of the energy levels, their types (donor or acceptor) and corresponding capture cross-sections. By this method we have found deep levels responsible for the polarization of CdZnTe detector under high photon-fluxes. Identified deep levels {{E}\\text{v}}+0.41 eV, {{E}\\text{v}}+0.77 eV and {{E}\\text{v}}+0.94 eV can capture the photo-generated holes and thus form a positive space charge, which is responsible for polarization of the detector.

  4. Luminescent Colloidal Semiconductor Nanocrystals Containing Copper: Synthesis, Photophysics, and Applications.

    Science.gov (United States)

    Knowles, Kathryn E; Hartstein, Kimberly H; Kilburn, Troy B; Marchioro, Arianna; Nelson, Heidi D; Whitham, Patrick J; Gamelin, Daniel R

    2016-09-28

    Copper-doped semiconductors are classic phosphor materials that have been used in a variety of applications for many decades. Colloidal copper-doped semiconductor nanocrystals have recently attracted a great deal of interest because they combine the solution processability and spectral tunability of colloidal nanocrystals with the unique photoluminescence properties of copper-doped semiconductor phosphors. Although ternary and quaternary semiconductors containing copper, such as CuInS2 and Cu2ZnSnS4, have been studied primarily in the context of their photovoltaic applications, when synthesized as colloidal nanocrystals, these materials have photoluminescence properties that are remarkably similar to those of copper-doped semiconductor nanocrystals. This review focuses on the luminescent properties of colloidal copper-doped, copper-based, and related copper-containing semiconductor nanocrystals. Fundamental investigations into the luminescence of copper-containing colloidal nanocrystals are reviewed in the context of the well-established luminescence mechanisms of bulk copper-doped semiconductors and copper(I) molecular coordination complexes. The use of colloidal copper-containing nanocrystals in applications that take advantage of their luminescent properties, such as bioimaging, solid-state lighting, and luminescent solar concentrators, is also discussed.

  5. Physics of semiconductor devices

    CERN Document Server

    Rudan, Massimo

    2015-01-01

    This book describes the basic physics of semiconductors, including the hierarchy of transport models, and connects the theory with the functioning of actual semiconductor devices.  Details are worked out carefully and derived from the basic physics, while keeping the internal coherence of the concepts and explaining various levels of approximation. Examples are based on silicon due to its industrial importance. Several chapters are included that provide the reader with the quantum-mechanical concepts necessary for understanding the transport properties of crystals. The behavior of crystals incorporating a position-dependent impurity distribution is described, and the different hierarchical transport models for semiconductor devices are derived (from the Boltzmann transport equation to the hydrodynamic and drift-diffusion models). The transport models are then applied to a detailed description of the main semiconductor-device architectures (bipolar, MOS). The final chapters are devoted to the description of s...

  6. Defects in semiconductor nanostructures

    Indian Academy of Sciences (India)

    Vijay A Singh; Manoj K Harbola; Praveen Pathak

    2008-02-01

    Impurities play a pivotal role in semiconductors. One part in a million of phosphorous in silicon alters the conductivity of the latter by several orders of magnitude. Indeed, the information age is possible only because of the unique role of shallow impurities in semiconductors. Although work in semiconductor nanostructures (SN) has been in progress for the past two decades, the role of impurities in them has been only sketchily studied. We outline theoretical approaches to the electronic structure of shallow impurities in SN and discuss their limitations. We find that shallow levels undergo a SHADES (SHAllow-DEep-Shallow) transition as the SN size is decreased. This occurs because of the combined effect of quantum confinement and reduced dielectric constant in SN. Level splitting is pronounced and this can perhaps be probed by ESR and ENDOR techniques. Finally, we suggest that a perusal of literature on (semiconductor) cluster calculations carried out 30 years ago would be useful.

  7. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  8. A semiconductor laser

    Energy Technology Data Exchange (ETDEWEB)

    Naoko, O.; Masaru, K.

    1984-04-20

    A semiconductor laser with enhanced characteristics is patented in which bleaching coatings are generated on the outcoupling mirrors by sputtering alternating coating layers made from A1203 and A10, with high and low indices of refraction.

  9. SILICON CARBIDE FOR SEMICONDUCTORS

    Science.gov (United States)

    This state-of-the-art survey on silicon carbide for semiconductors includes a bibliography of the most important references published as of the end...of 1964. The various methods used for growing silicon carbide single crystals are reviewed, as well as their properties and devices fabricated from...them. The fact that the state of-the-art of silicon carbide semiconductors is not further advanced may be attributed to the difficulties of growing

  10. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  11. Device fabrication, characterization, and thermal neutron detection response of LiZnP and LiZnAs semiconductor devices

    Science.gov (United States)

    Montag, Benjamin W.; Ugorowski, Philip B.; Nelson, Kyle A.; Edwards, Nathaniel S.; McGregor, Douglas S.

    2016-11-01

    Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled 3He and 10BF3 detectors. The 6Li(n,t)4He reaction yields a total Q-value of 4.78 MeV, larger than 10B, an energy easily identified above background radiations. Hence, devices fabricated from semiconductor compounds having either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10-6 Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The raw synthesized material indicated the presence high impurity levels (material and electrical property characterizations). A static vacuum sublimation in quartz was performed to help purify the synthesized material [2,3]. Bulk crystalline samples were grown from the purified material [4,5]. Samples were cut using a diamond wire saw, and processed into devices. Bulk resistivity was determined from I-V curve measurements, ranging from 106-1011 Ω cm. Devices were characterized for sensitivity to 5.48 MeV alpha particles, 337 nm laser light, and neutron sensitivity in a thermal neutron diffracted beam at the Kansas State University TRIGA Mark II nuclear reactor. Thermal neutron reaction product charge induction was measured with a LiZnP device, and the reaction product spectral response was observed.

  12. Radiation detectors: needs and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Armantrout, G.A.

    1981-01-01

    Important applications for x- and ..gamma..-ray spectroscopy are found in prospecting, materials characterization, environmental monitoring, the life sciences, and nuclear physics. The specific requirements vary for each application with varying degrees of emphasis on either spectrometer resolution, detection efficiency, or both. Since no one spectrometer is ideally suited to this wide range of needs, compromises are usually required. Gas and scintillation spectrometers have reached a level of maturity, and recent interest has concentrated on semiconductor spectrometers. Germanium detectors are showing continuing refinement and are the spectrometers of choice for high resolution applications. The new high-Z semiconductors, such as CdTe and HgI/sub 2/, have shown steady improvement but are limited in both resolution and size and will likely be used only in applications which require their unique properties.

  13. Status of radiation detector and neutron monitor technology

    CERN Document Server

    Kim, Y K; Ha, J H; Han, S H; Hong, S B; Hwang, I K; Lee, W G; Moon, B S; Park, S H; Song, M H

    2002-01-01

    In this report, we describe the current states of the radiation detection technology, detectors for industrial application, and neutron monitors. We also survey the new technologies being applied to this field. The method to detect radiation is the measurement of the observable secondary effect from the interaction between incident radiation and detector material, such as ionization, excitation, fluorescence, and chemical reaction. The radiation detectors can be categorized into gas detectors, scintillation detectors, and semiconductor detectors according to major effects and main applications. This report contains the current status and operational principles of these detectors. The application fields of radiation detectors are industrial measurement system, in-core neutron monitor, medical radiation diagnostic device, nondestructive inspection device, environmental radiation monitoring, cosmic-ray measurement, security system, fundamental science experiment, and radiation measurement standardization. The st...

  14. Segmented AC-coupled readout from continuous collection electrodes in semiconductor sensors

    Energy Technology Data Exchange (ETDEWEB)

    Sadrozinski, Hartmut F. W.; Seiden, Abraham; Cartiglia, Nicolo

    2017-04-04

    Position sensitive radiation detection is provided using a continuous electrode in a semiconductor radiation detector, as opposed to the conventional use of a segmented electrode. Time constants relating to AC coupling between the continuous electrode and segmented contacts to the electrode are selected to provide position resolution from the resulting configurations. The resulting detectors advantageously have a more uniform electric field than conventional detectors having segmented electrodes, and are expected to have much lower cost of production and of integration with readout electronics.

  15. Effect of bulk charged impurities on the bulk and surface transport in three-dimensional topological insulators

    OpenAIRE

    2013-01-01

    In the three-dimensional topological insulator (TI), the physics of doped semiconductors exists literally side-by-side with the physics of ultra-relativistic Dirac fermions. This unusual pairing creates a novel playground for studying the interplay between disorder and electronic transport. In this mini-review we focus on the disorder caused by the three-dimensionally distributed charged impurities that are ubiquitous in TIs, and we outline the effects it has on both the bulk and surface tran...

  16. Novel room temperature ferromagnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Amita [KTH Royal Inst. of Technology, Stockholm (Sweden)

    2004-06-01

    Today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one 'spintronic' device that exploits both charge and 'spin' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 mu-m thick transparent pulsed laser deposited films of the Mn (<4 at. percent) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm areas showed homogeneous

  17. Novel room temperature ferromagnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Amita

    2004-11-01

    Today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one 'spintronic' device that exploits both charge and 'spin' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 mu-m thick transparent pulsed laser deposited films of the Mn (<4 at. percent) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm areas showed homogeneous

  18. Characterization of a dose verification system dedicated to radiotherapy treatments based on a silicon detector multi-strips; Caracterizacion de un sistema de verificacion de dosis dedicado a tratamientos de radioterapia basado en un detector de silicio de multi-tiras

    Energy Technology Data Exchange (ETDEWEB)

    Bocca, A.; Cortes Giraldo, M. A.; Gallardo, M. I.; Espino, J. M.; Aranas, R.; Abou Haidar, Z.; Alvarez, M. A. G.; Quesada, J. M.; Vega-Leal, A. P.; Perez Neto, F. J.

    2011-07-01

    In this paper, we present the characterization of a silicon detector multi-strips (SSSSD: Single Sided Silicon Strip Detector), developed by the company Micron Semiconductors Ltd. for use as a verification system for radiotherapy treatments.

  19. Time Evolution of Electric Fields in CDMS Detectors

    CERN Document Server

    Leman, S W; Brink, P L; Cabrera, B; Chagani, H; Cherry, M; Cushman, P; Silva, E Do Couto E; Doughty, T; Figueroa-Feliciano, E; Mandic, V; McCarthy, K A; Mirabolfathi, N; Pyle, M; Reisetter, A; Resch, R; Sadoulet, B; Serfass, B; Sundqvist, K M; Tomada, A; Young, B A; Zhang, J

    2011-01-01

    The Cryogenic Dark Matter Search (CDMS) utilizes large mass, 3" diameter x 1" thick target masses as particle detectors. The target is instrumented with both phonon and ionization sensors, the later providing a $\\sim$1 V cm$^{-1}$ electric field in the detector bulk. Cumulative radiation exposure which creates $\\sim 200\\times 10^6$ electron-hole pairs is sufficient to produce a comparable reverse field in the detector thereby degrading the ionization channel performance. To study this, the existing CDMS detector Monte Carlo has been modified to allow for an event by event evolution of the bulk electric field, in three spatial dimensions. Our most resent results and interpretation are discussed.

  20. Method of doping a semiconductor

    Science.gov (United States)

    Yang, Chiang Y.; Rapp, Robert A.

    1983-01-01

    A method for doping semiconductor material. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient.

  1. Radiative Bulk Viscosity

    CERN Document Server

    Chen, X

    2001-01-01

    Viscous resistance to changes in the volume of a gas arises when different degrees of freedom have different relaxation times. Collisions tend to oppose the resulting departures from equilibrium and, in so doing, generate entropy. Even for a classical gas of hard spheres, when the mean free paths or mean flight times of constituent particles are long, we find a nonvanishing bulk viscosity. Here we apply a method recently used to uncover this result for a classical rarefied gas to radiative transfer theory and derive an expression for the radiative stress tensor for a gray medium with absorption and Thomson scattering. We determine the transport coefficients through the calculation of the comoving entropy generation. When scattering dominates absorption, the bulk viscosity becomes much larger than either the shear viscosity or the thermal conductivity.

  2. Influence of High Harmonics of Magnetic Fields on Trapped Magnetic Fluxes in HTS Bulk

    Science.gov (United States)

    Yamagishi, K.; Miyagi, D.; Tsukamoto, O.

    Various kinds of HTS bulk motors are proposed and have been developed. Generally, those motors are driven by semiconductor inverters and currents fed to the armature windings contain high harmonics. Therefore, the bulks are exposed to high harmonics magnetic fields and AC losses are produced in the bulks. The AC losses deteriorate the efficiency of the motors and cause temperature rise of the bulks which decrease the trapped magnetic fluxes of the bulks. Usually, electro-magnetic shielding devices are inserted between the bulks and armature windings. However, the shielding devices degrade compactness of the motors. Therefore, it is important to have knowledge of the influence of the high harmonics magnetic fields on the AC losses and trapped magnetic fluxes of the bulk for optimum design of the shielding devices. In this work, the authors experimentally study the influence of high harmonics magnetic fields.

  3. COHERENT LIDAR SYSTEM BASED ON A SEMICONDUCTOR LASER AND AMPLIFIER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a compact, reliable and low-cost coherent LIDAR (Light Detection And Ranging) system for remote wind-speed determination, determination of particle concentration, and/or temperature based on an all semiconductor light source and related methods. The present...... invention provides a coherent LIDAR system comprising a semiconductor laser for emission of a measurement beam of electromagnetic radiation directed towards a measurement volume for illumination of particles in the measurement volume, a reference beam generator for generation of a reference beam, a detector...

  4. Calorimeter detectors

    CERN Document Server

    de Barbaro, P; The ATLAS collaboration

    2013-01-01

    Although the instantaneous and integrated luminosity in HL-LHC will be far higher than the LHC detectors were originally designed for, the Barrel calorimeters of the four experiments are expected to continue to perform well  throughout the Phase II program. The conditions for the End-Cap calorimeters are far more challenging and whilst some detectors will require relatively modest changes, others require far more substantial upgrades. We present the results of longevity and performance studies for the calorimeter systems of the four main LHC experiments and outline the upgrade options under consideration. We include a discussion of the R&D required to make the final technology choices for the upgraded detectors.

  5. Basic Semiconductor Physics

    CERN Document Server

    Hamaguchi, Chihiro

    2010-01-01

    This book presents a detailed description of the basic semiconductor physics. The reader is assumed to have a basic command of mathematics and some elementary knowledge of solid state physics. The text covers a wide range of important phenomena in semiconductors, from the simple to the advanced. The reader can understand three different methods of energy band calculations, empirical pseudo-potential, k.p perturbation and tight-binding methods. The effective mass approximation and electron motion in a periodic potential, Boltzmann transport equation and deformation potentials used for full band Monte Carlo simulation are discussed. Experiments and theoretical analysis of cyclotron resonance are discussed in detail because the results are essential to the understanding of semiconductor physics. Optical and transport properties, magneto-transport, two dimensional electron gas transport (HEMT and MOSFET), and quantum transport are reviewed, explaining optical transition, electron phonon interactions, electron mob...

  6. Fundamentals of semiconductor lasers

    CERN Document Server

    Numai, Takahiro

    2015-01-01

    This book explains physics under the operating principles of semiconductor lasers in detail based on the experience of the author, dealing with the first manufacturing of phase-shifted DFB-LDs and recent research on transverse modes.   The book also bridges a wide gap between journal papers and textbooks, requiring only an undergraduate-level knowledge of electromagnetism and quantum mechanics, and helps readers to understand journal papers where definitions of some technical terms vary, depending on the paper. Two definitions of the photon density in the rate equations and two definitions of the phase-shift in the phase-shifted DFB-LD are explained, and differences in the calculated results are indicated, depending on the definitions.    Readers can understand the physics of semiconductor lasers and analytical tools for Fabry-Perot LDs, DFB-LDs, and VCSELs and will be stimulated to develop semiconductor lasers themselves.

  7. Beyond amorphous organic semiconductors

    Science.gov (United States)

    Hanna, Jun-ichi

    2003-07-01

    Recently it has been discovered that some types of liquid crystals, which believed to be governed by ionic conduction, exhibit a very fast electronic conduction. Their charge carrier transport is characterized by high mobility over 10-2 cm2/Vs independent of electric field and temperature. Now, the liquid crystals are being recognized as a new class of organic semiconductors. In this article, a new aspect of liquid crystals as a self-organizing molecular semiconductor are reviewed, focused on their basic charge carrier transport properties and discussed in comparison with those of molecular crystals and amorphous materials. And it is concluded that the liquid crystal is promising as a quality organic semiconductor for the devices that require a high mobility.

  8. Photoelectronic properties of semiconductors

    CERN Document Server

    Bube, Richard H

    1992-01-01

    The interaction between light and electrons in semiconductors forms the basis for many interesting and practically significant properties. This book examines the fundamental physics underlying this rich complexity of photoelectronic properties of semiconductors, and will familiarise the reader with the relatively simple models that are useful in describing these fundamentals. The basic physics is also illustrated with typical recent examples of experimental data and observations. Following introductory material on the basic concepts, the book moves on to consider a wide range of phenomena, including photoconductivity, recombination effects, photoelectronic methods of defect analysis, photoeffects at grain boundaries, amorphous semiconductors, photovoltaic effects and photoeffects in quantum wells and superlattices. The author is Professor of Materials Science and Electrical Engineering at Stanford University, and has taught this material for many years. He is an experienced author, his earlier books having fo...

  9. Investigation of DEPFET as vertex detector at ILC. Intrinsic properties, radiation hardness and alternative readout schemes

    Energy Technology Data Exchange (ETDEWEB)

    Rummel, Stefan

    2009-07-20

    The International Linear Collider (ILC) is supposed to be the next generation lepton collider. The detectors at ILC are intended to be precision instruments improving the performance in impact parameter (IP), momentum and energy resolution significantly compared to previous detectors at lepton colliders. To achieve this goal it is necessary to develop new detector technologies or pushing existing technologies to their technological edges. Regarding the Vertex detector (VTX) this implies challenges in resolution, material budget, power consumption and readout speed. A promising technology for the Vertex detector is the Depleted Field Effect Transistor (DEPFET). The DEPFET is a semiconductor device with in-pixel ampli cation integrated on a fully depleted bulk. This allows building detectors with intrinsically high SNR due to the large sensitive volume and the small input capacitance at the rst ampli er. To reach the ambitious performance goals it is important to understand its various features: clear performance, internal amplification, noise and radiation hardness. The intrinsic noise is analyzed, showing that the contribution of the DEPFET is below 50 e{sup -} at the required speed. Moreover it is possible to show that the internal ampli cation could be further improved to more than 1nA/e{sup -} using the standard DEPFET technology. The clear performance is investigated on matrix level utilizing a dedicated setup for single pixel testing which allows direct insight into the DEPFET operation, without the complexity of the full readout system. It is possible to show that a full clear could be achieved with a voltage pulse of 10 V. Furthermore a novel clear concept - the capacitive coupled clear gate - is demonstrated. The radiation hardness is studied with respect to the system performance utilizing various irradiations with ionizing and non ionizing particles. The impact on the bulk as well as the interface damage is investigated. Up to now the readout is performed

  10. Massive silicon or germanium detectors at cryogenic temperature

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dip. Fisica dell' Universita di Ferrara and INFN, via del Paradiso 12, 44100 Ferrara (Italy); Bressi, G. [INFN, sez.Pavia, Via U. Bassi 6, 27100 Pavia (Italy); Carugno, G. [INFN, sez. Padova, Via Marzolo 8, 35131 Padova (Italy); Feltrin, E. [INFN, Lab. Naz. Legnaro, Via dell' Universita 1, 35020 Legnaro (PD) (Italy)]. E-mail: feltrin@lnl.infn.it; Galeazzi, G. [INFN, Lab. Naz. Legnaro, Via dell' Universita 1, 35020 Legnaro (PD) (Italy)

    2006-11-30

    Several massive silicon and germanium home-made detectors, working at cryogenic temperature, have been studied. They are the benchmarking schemes to check the possibility of realizing a semiconductor time projection chamber that could have various interesting applications in weak interaction problems. Reported here are the first results on investigations of charge collection efficiency and metal-semiconductor contact hardness. The leakage current, total depletion voltage and alpha or gamma spectroscopy are presented.

  11. Optical processes in semiconductors

    CERN Document Server

    Pankove, Jacques I

    1975-01-01

    Based on a series of lectures at Berkeley, 1968-1969, this is the first book to deal comprehensively with all of the phenomena involving light in semiconductors. The author has combined, for the graduate student and researcher, a great variety of source material, journal research, and many years of experimental research, adding new insights published for the first time in this book.Coverage includes energy states in semiconductors and their perturbation by external parameters, absorption, relationships between optical constants, spectroscopy, radiative transitions, nonradiative recombination

  12. Advances in semiconductor lasers

    CERN Document Server

    Coleman, James J; Jagadish, Chennupati

    2012-01-01

    Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. Originally widely known as the ""Willardson and Beer"" Series, it has succeeded in publishing numerous landmark volumes and chapters. The series publishes timely, highly relevant volumes intended for long-term impact and reflecting the truly interdisciplinary nature of the field. The volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in academia, scien

  13. Introductory semiconductor device physics

    CERN Document Server

    Parker, Greg

    2004-01-01

    ATOMS AND BONDINGThe Periodic TableIonic BondingCovalent BondingMetallic bondingvan der Waals BondingStart a DatabaseENERGY BANDS AND EFFECTIVE MASSSemiconductors, Insulators and MetalsSemiconductorsInsulatorsMetalsThe Concept of Effective MassCARRIER CONCENTRATIONS IN SEMICONDUCTORSDonors and AcceptorsFermi-LevelCarrier Concentration EquationsDonors and Acceptors Both PresentCONDUCTION IN SEMICONDUCTORSCarrier DriftCarrier MobilitySaturated Drift VelocityMobility Variation with TemperatureA Derivation of Ohm's LawDrift Current EquationsSemiconductor Band Diagrams with an Electric Field Presen

  14. Ternary chalcopyrite semiconductors

    CERN Document Server

    Shay, J L; Pamplin, B R

    2013-01-01

    Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications covers the developments of work in the I-III-VI2 and II-IV-V2 ternary chalcopyrite compounds. This book is composed of eight chapters that focus on the crystal growth, characterization, and applications of these compounds to optical communications systems. After briefly dealing with the status of ternary chalcopyrite compounds, this book goes on describing the crystal growth of II-IV-V2 and I-III-VI2 single crystals. Chapters 3 and 4 examine the energy band structure of these semiconductor compounds, illustrat

  15. Quantum Transport in Semiconductors

    Science.gov (United States)

    1991-10-01

    SRS i 91 4. TITLE AND SUBTITLE Quantum Transport in Semiconductors 5. FUNDING NUMBER söMtos-rizk-ooss 6. AUTHOR(S) D. K. Ferry ©fte ELECTE...OF ABSTRACT UL NSN 7540-01-280-5500 O 1 9 Standard Form 298 (Rev. 2-89) Presented by ANSI Std «9-18 298-102 Final Report Quantum Transport in... Quantum Transport in Semiconductor Devices This final report describes a program of research investigating quantum effects which become important in

  16. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  17. Semiconductor surface protection material

    Science.gov (United States)

    Packard, R. D. (Inventor)

    1973-01-01

    A method and a product for protecting semiconductor surfaces is disclosed. The protective coating material is prepared by heating a suitable protective resin with an organic solvent which is solid at room temperature and converting the resulting solution into sheets by a conventional casting operation. Pieces of such sheets of suitable shape and thickness are placed on the semiconductor areas to be coated and heat and vacuum are then applied to melt the sheet and to drive off the solvent and cure the resin. A uniform adherent coating, free of bubbles and other defects, is thus obtained exactly where it is desired.

  18. Engineering magnetism in semiconductors

    Directory of Open Access Journals (Sweden)

    Tomasz Dietl

    2006-11-01

    Full Text Available Transition metal doped III-V, II-VI, and group IV compounds offer an unprecedented opportunity to explore ferromagnetism in semiconductors. Because ferromagnetic spin-spin interactions are mediated by holes in the valence band, changing the Fermi level using co-doping, electric fields, or light can directly manipulate the magnetic ordering. Moreover, engineering the Fermi level position by co-doping makes it possible to modify solubility and self-compensation limits, affecting magnetic characteristics in a number of surprising ways. The Fermi energy can even control the aggregation of magnetic ions, providing a new route to self-organization of magnetic nanostructures in a semiconductor host.

  19. ATLAS Fact Sheet : To raise awareness of the ATLAS detector and collaboration on the LHC

    CERN Multimedia

    ATLAS Outreach

    2010-01-01

    Facts on the Detector, Calorimeters, Muon System, Inner Detector, Pixel Detector, Semiconductor Tracker, Transition Radiation Tracker,, Surface hall, Cavern, Detector, Magnet system, Solenoid, Toroid, Event rates, Physics processes, Supersymmetric particles, Comparing LHC with Cosmic rays, Heavy ion collisions, Trigger and Data Acquisition TDAQ, Computing, the LHC and the ATLAS collaboration. This fact sheet also contains images of ATLAS and the collaboration as well as a short list of videos on ATLAS available for viewing.

  20. Radiation Hardening of Silicon Detectors

    CERN Multimedia

    Leroy, C; Glaser, M

    2002-01-01

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

  1. Handbook of luminescent semiconductor materials

    CERN Document Server

    Bergman, Leah

    2011-01-01

    Photoluminescence spectroscopy is an important approach for examining the optical interactions in semiconductors and optical devices with the goal of gaining insight into material properties. With contributions from researchers at the forefront of this field, Handbook of Luminescent Semiconductor Materials explores the use of this technique to study semiconductor materials in a variety of applications, including solid-state lighting, solar energy conversion, optical devices, and biological imaging. After introducing basic semiconductor theory and photoluminescence principles, the book focuses

  2. Metal semiconductor contacts and devices

    CERN Document Server

    Cohen, Simon S; Einspruch, Norman G

    1986-01-01

    VLSI Electronics Microstructure Science, Volume 13: Metal-Semiconductor Contacts and Devices presents the physics, technology, and applications of metal-semiconductor barriers in digital integrated circuits. The emphasis is placed on the interplay among the theory, processing, and characterization techniques in the development of practical metal-semiconductor contacts and devices.This volume contains chapters that are devoted to the discussion of the physics of metal-semiconductor interfaces and its basic phenomena; fabrication procedures; and interface characterization techniques, particularl

  3. XMASS detector

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hieda, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Hiraide, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hirano, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kishimoto, Y.; Kobayashi, K.; Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nakagawa, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Ogawa, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); and others

    2013-07-11

    The XMASS project aims to detect dark matter, pp and {sup 7}Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  4. XMASS detector

    CERN Document Server

    Abe, K; Hiraide, K; Hirano, S; Kishimoto, Y; Kobayashi, K; Moriyama, S; Nakagawa, K; Nakahata, M; Nishiie, H; Ogawa, H; Oka, N; Sekiya, H; Shinozaki, A; Suzuki, Y; Takeda, A; Takachio, O; Ueshima, K; Umemoto, D; Yamashita, M; Yang, B S; Tasaka, S; Liu, J; Martens, K; Hosokawa, K; Miuchi, K; Murata, A; Onishi, Y; Otsuka, Y; Takeuchi, Y; Kim, Y H; Lee, K B; Lee, M K; Lee, J S; Fukuda, Y; Itow, Y; Nishitani, Y; Masuda, K; Takiya, H; Uchida, H; Kim, N Y; Kim, Y D; Kusaba, F; Motoki, D; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2013-01-01

    The XMASS project aims to detect dark matter, pp and $^{7}$Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  5. Intense terahertz excitation of semiconductors

    CERN Document Server

    Ganichev, S D

    2006-01-01

    This work presents the first comprehensive treatment of high-power terahertz applications to semiconductors and low-dimensional semiconductor structures. Terahertz properties of semiconductors are in the centre of scientific activities because of the need of high-speed electronics.

  6. Numerical method and analysis of computational fluid mechanics for photoelectric semiconducting detector

    Institute of Scientific and Technical Information of China (English)

    Yi-rang YUAN; Chang-feng LI; Yun-xin LIU; Li-qin MA

    2009-01-01

    We propose a modified upwind finite difference fractional step scheme for the computational fluid mechanics simulations of a three-dimensional photoelectric semiconductor detector. We obtain the optimal l2-norm error estimates by using the techniques including the calculus of variations, the energy methods, the induction hypothesis, and a priori estimates. The proposed scheme is successfully applied to the simulation of the photoelectric semiconductor detectors.

  7. Epitaxial and bulk growth of cubic silicon carbide on off-oriented 4H-silicon carbide substrates

    OpenAIRE

    Norén, Olof

    2015-01-01

    The growth of bulk cubic silicon carbide has for a long time seemed to be something for the future. However, in this thesis the initial steps towards bulk cubic silicon carbide have been taken. The achievement of producing bulk cubic silicon carbide will have a great impact in various fields of science and industry such as for example the fields of semiconductor technology within electronic- and optoelectronic devices and bio-medical applications. The process that has been used to grow the bu...

  8. Biexcitons in semiconductor microcavities

    DEFF Research Database (Denmark)

    Borri, P.; Langbein, W.; Woggon, U.

    2003-01-01

    In this paper, the present status of the experimental study of the optical properties of biexcitons in semiconductor microcavities is reviewed. In particular, a detailed investigation of a polariton-biexciton transition in a high-quality single quantum well GaAs/AlGaAs microcavity is reported...

  9. Bulk growth and surface characterization of epitaxy ready cadmium zinc telluride substrates for use in IR imaging applications

    Science.gov (United States)

    Flint, J. P.; Martinez, B.; Betz, T. E. M.; MacKenzie, J.; Kumar, F. J.; Bindley, G.

    2016-05-01

    Cadmium Zinc Telluride (CZT) is an important compound semiconductor material upon which Mercury Cadmium Telluride (MCT) layers are deposited epitaxially to form structures that are used in high performance detectors covering a wide infrared (IR) spectral band. The epitaxial growth of high quality MCT layers presents many technical challenges and a critical determinant of material performance is the quality of the underlying bulk CZT substrate. CZT itself is a difficult material to manufacture where traditional methods of bulk growth are complex and low yielding, which constrains the supply of commercially available substrates. In this work we report on the epitaxy-ready finishing of Travelling Heather Method (THM) grown Cd0.96Zn0.04Te substrates. The THM method is well established for the growth of high quality CZT crystals used in nuclear, X-ray and spectroscopic imaging applications and in this work we demonstrate the application of this technique to the growth of IR specification CZT substrates with areas of up to 5 cm x 5 cm square. We will discuss the advantages of the THM method over alternative methods of bulk CZT growth where the high yield and material uniformity advantages of this technique will be demonstrated. Chemo-mechanical polishing (CMP) of 4 cm x 4 cm CZT substrates reveals that III-V (InSb/GaSb) like levels of epitaxy-ready surface finishing may be obtained with modified process chemistries. Surface quality assessments will be made by various surface analytical and microscopy techniques from which the suitability of the material for subsequent assessment of quality by epitaxial growth will be ascertained.

  10. The color of X-rays: Spectral X-ray computed tomography using energy sensitive pixel detectors

    NARCIS (Netherlands)

    Schioppa, E.J.

    2014-01-01

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray flu

  11. Pixel detectors from fundamentals to applications

    CERN Document Server

    Rossi, Leonardo; Rohe, Tilman; Wermes, Norbert

    2006-01-01

    Pixel detectors are a particularly important class of particle and radiation detection devices. They have an extremely broad spectrum of applications, ranging from high-energy physics to the photo cameras of everyday life. This book is a general purpose introduction into the fundamental principles of pixel detector technology and semiconductor-based hybrid pixel devices. Although these devices were developed for high-energy ionizing particles and radiation beyond visible light, they are finding new applications in many other areas. This book will therefore benefit all scientists and engineers working in any laboratory involved in developing or using particle detection.

  12. OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES

    Energy Technology Data Exchange (ETDEWEB)

    Grant, C D; Zhang, J Z

    2007-09-28

    This chapter provides an overview of some recent research activities on the study of optical and dynamic properties of semiconductor nanomaterials. The emphasis is on unique aspects of these properties in nanostructures as compared to bulk materials. Linear, including absorption and luminescence, and nonlinear optical as well as dynamic properties of semiconductor nanoparticles are discussed with focus on their dependence on particle size, shape, and surface characteristics. Both doped and undoped semiconductor nanomaterials are highlighted and contrasted to illustrate the use of doping to effectively alter and probe nanomaterial properties. Some emerging applications of optical nanomaterials are discussed towards the end of the chapter, including solar energy conversion, optical sensing of chemicals and biochemicals, solid state lighting, photocatalysis, and photoelectrochemistry.

  13. Evaluation of efficiency of a semiconductor gamma camera

    CERN Document Server

    Otake, H; Takeuchi, Y

    2002-01-01

    We evaluation basic characteristics of a compact type semiconductor gamma camera (eZ-SCOPE AN) of Cadmium Zinc Telluride (CdZnTe). This new compact gamma camera has 256 semiconductors representing the same number of pixels. Each semiconductor is 2 mm square and is located in 16 lines and rows on the surface of the detector. The specific performance characteristics were evaluated in the study referring to National Electrical Manufactures Association (NEMA) standards; intrinsic energy resolution, intrinsic count rate performance, integral uniformity, system planar sensitivity, system spatial resolution, and noise to the neighboring pixels. The intrinsic energy resolution measured 5.7% as full width half maximum (FWHM). The intrinsic count rate performance ranging from 17 kcps to 1,285 kcps was evaluated, but the highest intrinsic count rate was not observed. Twenty percents count loss was recognized at 1,021 kcps. The integral uniformity was 1.3% with high sensitivity collimator. The system planar sensitivity w...

  14. Performance Studies of Bulk Micromegas of Different Design Parameters

    CERN Document Server

    Bhattacharya, Purba; Majumdar, Nayana; Mukhopadhyay, Supratik; Sarkar, Sandip; Colas, Paul; Attie, David

    2016-01-01

    The present work involves the comparison of various bulk Micromegas detectors having different design parameters. Six detectors with amplification gaps of $64,~128,~192,~220 ~\\mu\\mathrm{m}$ and mesh hole pitch of $63,~78 ~\\mu\\mathrm{m}$ were tested at room temperature and normal gas pressure. Two setups were built to evaluate the effect of the variation of the amplification gap and mesh hole pitch on different detector characteristics. The gain, energy resolution and electron transmission of these Micromegas detectors were measured in Argon-Isobutane (90:10) gas mixture while the measurements of the ion backflow were carried out in P10 gas. These measured characteristics have been compared in detail to the numerical simulations using the Garfield framework that combines packages such as neBEM, Magboltz and Heed.

  15. Methods of measurement for semiconductor materials, process control, and devices

    Science.gov (United States)

    Bullis, W. M. (Editor)

    1972-01-01

    Significant accomplishments include development of a procedure to correct for the substantial differences of transistor delay time as measured with different instruments or with the same instrument at different frequencies; association of infrared response spectra of poor quality germanium gamma ray detectors with spectra of detectors fabricated from portions of a good crystal that had been degraded in known ways; and confirmation of the excellent quality and cosmetic appearance of ultrasonic bonds made with aluminum ribbon wire. Work is continuing on measurement of resistivity of semiconductor crystals; study of gold-doped silicon, development of the infrared response technique; evaluation of wire bonds and die attachment; and measurement of thermal properties of semiconductor devices, delay time and related carrier transport properties in junction devices, and noise properties of microwave diodes.

  16. Optical Studies of Single Semiconductor Nanowires by Micro-Photoluminescence Spectroscopy

    OpenAIRE

    Karlberg, Thomas Andre

    2010-01-01

    Over the recent years semiconductor nanowires have gained much attention for their potential to either improve existing technology or create novel devices. This potential has been realized in devices such as semiconductor nanowire lasers[2-3] and nanowire single-photon detectors[4]. With nanowire technology it could be possible to create single-photon nanowire lasers that emit photons in the near infrared region. Such devices should prove very interesting for telecommunications and quantum c...

  17. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  18. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  19. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  20. Explosive bulk charge

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  1. The two sides of silicon detectors

    CERN Document Server

    Devine, S R

    2001-01-01

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

  2. A hard oxide semiconductor with a direct and narrow bandgap and switchable p-n electrical conduction.

    Science.gov (United States)

    Ovsyannikov, Sergey V; Karkin, Alexander E; Morozova, Natalia V; Shchennikov, Vladimir V; Bykova, Elena; Abakumov, Artem M; Tsirlin, Alexander A; Glazyrin, Konstantin V; Dubrovinsky, Leonid

    2014-12-23

    An oxide semiconductor (perovskite-type Mn2 O3 ) is reported which has a narrow and direct bandgap of 0.45 eV and a high Vickers hardness of 15 GPa. All the known materials with similar electronic band structures (e.g., InSb, PbTe, PbSe, PbS, and InAs) play crucial roles in the semiconductor industry. The perovskite-type Mn2 O3 described is much stronger than the above semiconductors and may find useful applications in different semiconductor devices, e.g., in IR detectors.

  3. Dead layer on silicon p–i–n diode charged-particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wall, B.L., E-mail: wallbl@uw.edu [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Amsbaugh, J.F. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Beglarian, A.; Bergmann, T. [Institute for Data Processing and Electronics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Bichsel, H.C.; Bodine, L.I.; Boyd, N.M.; Burritt, T.H. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Chaoui, Z. [Laboratory of Optoelectronics and Devices, Faculty of Science, University of Setif (Algeria); Corona, T.J. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC (United States); Triangle Universities Nuclear Laboratory, Durham, NC (United States); Doe, P.J.; Enomoto, S. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Harms, F. [Institute for Nuclear Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Harper, G.C. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Howe, M.A. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC (United States); Martin, E.L.; Parno, D.S.; Peterson, D.A. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA (United States); Petzold, L. [Institute for Data Processing and Electronics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Renschler, P. [Institute for Experimental Nuclear Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); and others

    2014-04-21

    Semiconductor detectors in general have a dead layer at their surfaces that is either a result of natural or induced passivation, or is formed during the process of making a contact. Charged particles passing through this region produce ionization that is incompletely collected and recorded, which leads to departures from the ideal in both energy deposition and resolution. The silicon p–i–n diode used in the KATRIN neutrino-mass experiment has such a dead layer. We have constructed a detailed Monte Carlo model for the passage of electrons from vacuum into a silicon detector, and compared the measured energy spectra to the predicted ones for a range of energies from 12 to 20 keV. The comparison provides experimental evidence that a substantial fraction of the ionization produced in the “dead” layer evidently escapes by diffusion, with 46% being collected in the depletion zone and the balance being neutralized at the contact or by bulk recombination. The most elementary model of a thinner dead layer from which no charge is collected is strongly disfavored.

  4. Dead layer on silicon p-i-n diode charged-particle detectors

    CERN Document Server

    Wall, B L; Beglarian, A; Bergmann, T; Bichsel, H C; Bodine, L I; Boyd, N M; Burritt, T H; Chaoui, Z; Corona, T J; Doeg, P J; Enomoto, S; Harms, F; Harper, G C; Howe, M A; Martin, E L; Parno, D S; Peterson, D A; Petzold, L; Renschler, P; Robertson, R G H; Schwarz, J; Steidl, M; Van Wechel, T D; VanDevender, B A; Wüstling, S; Wierman, K J; Wilkerson, J F

    2013-01-01

    Semiconductor detectors in general have a dead layer at their surfaces that is either a result of natural or induced passivation, or is formed during the process of making a contact. Charged particles passing through this region produce ionization that is incompletely collected and recorded, which leads to departures from the ideal in both energy deposition and resolution. The silicon \\textit{p-i-n} diode used in the KATRIN neutrino-mass experiment has such a dead layer. We have constructed a detailed Monte Carlo model for the passage of electrons from vacuum into a silicon detector, and compared the measured energy spectra to the predicted ones for a range of energies from 12 to 20 keV. The comparison provides experimental evidence that a substantial fraction of the ionization produced in the "dead" layer evidently escapes by diffusion, with 46% being collected in the depletion zone and the balance being neutralized at the contact or by bulk recombination. The most elementary model of a thinner dead layer fr...

  5. Dead layer on silicon p-i-n diode charged-particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wall, B. L.; Amsbaugh, John F.; Beglarian, A.; Bergmann, T.; Bichsel, H. C.; Bodine, L. I.; Boyd, N. M.; Burritt, Tom H.; Chaoui, Z.; Corona, T. J.; Doe, Peter J.; Enomoto, S.; Harms, F.; Harper, Gregory; Howe, M. A.; Martin, E. L.; Parno, D. S.; Peterson, David; Petzold, Linda; Renschler, R.; Robertson, R. G. H.; Schwarz, J.; Steidl, M.; Van Wechel, T. D.; VanDevender, Brent A.; Wustling, S.; Wierman, K. J.; Wilkerson, J. F.

    2014-04-21

    Abstract Semiconductor detectors in general have a dead layer at their surfaces that is either a result of natural or induced passivation, or is formed during the process of making a contact. Charged particles passing through this region produce ionization that is incompletely collected and recorded, which leads to departures from the ideal in both energy deposition and resolution. The silicon p-i-n diode used in the KATRIN neutrinomass experiment has such a dead layer. We have constructed a detailed Monte Carlo model for the passage of electrons from vacuum into a silicon detector, and compared the measured energy spectra to the predicted ones for a range of energies from 12 to 20 keV. The comparison provides experimental evidence that a substantial fraction of the ionization produced in the "dead" layer evidently escapes by discussion, with 46% being collected in the depletion zone and the balance being neutralized at the contact or by bulk recombination. The most elementary model of a thinner dead layer from which no charge is collected is strongly disfavored.

  6. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  7. Stretchable Organic Semiconductor Devices.

    Science.gov (United States)

    Qian, Yan; Zhang, Xinwen; Xie, Linghai; Qi, Dianpeng; Chandran, Bevita K; Chen, Xiaodong; Huang, Wei

    2016-11-01

    Stretchable electronics are essential for the development of intensely packed collapsible and portable electronics, wearable electronics, epidermal and bioimplanted electronics, 3D surface compliable devices, bionics, prosthesis, and robotics. However, most stretchable devices are currently based on inorganic electronics, whose high cost of fabrication and limited processing area make it difficult to produce inexpensive, large-area devices. Therefore, organic stretchable electronics are highly attractive due to many advantages over their inorganic counterparts, such as their light weight, flexibility, low cost and large-area solution-processing, the reproducible semiconductor resources, and the easy tuning of their properties via molecular tailoring. Among them, stretchable organic semiconductor devices have become a hot and fast-growing research field, in which great advances have been made in recent years. These fantastic advances are summarized here, focusing on stretchable organic field-effect transistors, light-emitting devices, solar cells, and memory devices.

  8. Polymer semiconductor crystals

    Directory of Open Access Journals (Sweden)

    Jung Ah Lim

    2010-05-01

    Full Text Available One of the long-standing challenges in the field of polymer semiconductors is to figure out how long interpenetrating and entangled polymer chains self-assemble into single crystals from the solution phase or melt. The ability to produce these crystalline solids has fascinated scientists from a broad range of backgrounds including physicists, chemists, and engineers. Scientists are still on the hunt for determining the mechanism of crystallization in these information-rich materials. Understanding the theory and concept of crystallization of polymer semiconductors will undoubtedly transform this area from an art to an area that will host a bandwagon of scientists and engineers. In this article we describe the basic concept of crystallization and highlight some of the advances in polymer crystallization from crystals to nanocrystalline fibers.

  9. Three dimensional strained semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  10. Semiconductor physics an introduction

    CERN Document Server

    Seeger, Karlheinz

    1999-01-01

    Semiconductor Physics - An Introduction - is suitable for the senior undergraduate or new graduate student majoring in electrical engineering or physics. It will also be useful to solid-state scientists and device engineers involved in semiconductor design and technology. The text provides a lucid account of charge transport, energy transport and optical processes, and a detailed description of many devices. It includes sections on superlattices and quantum well structures, the effects of deep-level impurities on transport, the quantum Hall effect and the calculation of the influence of a magnetic field on the carrier distribution function. This 6th edition has been revised and corrected, and new sections have been added to different chapters.

  11. Doping of organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Luessem, B.; Riede, M.; Leo, K. [Institut fuer Angewandte Photophysik, TU Dresden (Germany)

    2013-01-15

    The understanding and applications of organic semiconductors have shown remarkable progress in recent years. This material class has been developed from being a lab curiosity to the basis of first successful products as small organic LED (OLED) displays; other areas of application such as OLED lighting and organic photovoltaics are on the verge of broad commercialization. Organic semiconductors are superior to inorganic ones for low-cost and large-area optoelectronics due to their flexibility, easy deposition, and broad variety, making tailor-made materials possible. However, electrical doping of organic semiconductors, i.e. the controlled adjustment of Fermi level that has been extremely important to the success of inorganic semiconductors, is still in its infancy. This review will discuss recent work on both fundamental principles and applications of doping, focused primarily to doping of evaporated organic layers with molecular dopants. Recently, both p- and n-type molecular dopants have been developed that lead to efficient and stable doping of organic thin films. Due to doping, the conductivity of the doped layers increases several orders of magnitude and allows for quasi-Ohmic contacts between organic layers and metal electrodes. Besides reducing voltage losses, doping thus also gives design freedom in terms of transport layer thickness and electrode choice. The use of doping in applications like OLEDs and organic solar cells is highlighted in this review. Overall, controlled molecular doping can be considered as key enabling technology for many different organic device types that can lead to significant improvements in efficiencies and lifetimes. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Semiconductors for organic transistors

    OpenAIRE

    Antonio Facchetti

    2007-01-01

    Organic molecules/polymers with a π-conjugated (hetero)aromatic backbone are capable of transporting charge and interact efficiently with light. Therefore, these systems can act as semiconductors in opto-electronic devices similar to inorganic materials. However, organic chemistry offers tools for tailoring materials' functional properties via modifications of the molecular/monomeric units, opening new possibilities for inexpensive device manufacturing. This article reviews the fundamental as...

  13. Tunable Infrared Semiconductor Lasers

    Science.gov (United States)

    2013-12-20

    Lett. 81, 406-408 (2002). [20] M. Ito and T. Kimura, “Oscillation properties of AlGaAs DH Lasrs with an external grating,” IEEE J. Quant. Elec- tron...tuning range has been demonstrated on a large area index-coupled, optically pumped mid-infrared type-II semiconductor distributed feedback (DFB) laser...lithography (IL) technique is used to pattern this chirped grating with two coherent spherical waves. A new grating fabrication optical arrangement

  14. Lattice constant and hardness of InSb:Bi bulk crystals grown by vertical directional solidification

    Science.gov (United States)

    Maske, Dilip; Deshpande, Manisha; Choudhary, Rashmi; Gadkari, Dattatray

    2016-05-01

    Ingots of the Bi doped InSb (InSb1-xBix) bulk semiconductor crystals were grown by specially designed Vertical Directional Solidification (VDS) technique. Substrates of seven crystals grown with various composition values of x (0 ≤ x 0.05.

  15. Survey of semiconductor physics

    CERN Document Server

    Böer, Karl W

    1992-01-01

    Any book that covers a large variety of subjects and is written by one author lacks by necessity the depth provided by an expert in his or her own field of specialization. This book is no exception. It has been written with the encouragement of my students and colleagues, who felt that an extensive card file I had accumulated over the years of teaching solid state and semiconductor physics would be helpful to more than just a few of us. This file, updated from time to time, contained lecture notes and other entries that were useful in my research and permitted me to give to my students a broader spectrum of information than is available in typical textbooks. When assembling this material into a book, I divided the top­ ics into material dealing with the homogeneous semiconductor, the subject of the previously published Volume 1, and the inhomoge­ neous semiconductor, the subject of this Volume 2. In order to keep the book to a manageable size, sections of tutorial character which can be used as text for a g...

  16. Semiconductor Ion Implanters

    Science.gov (United States)

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at 7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at 6.2 billion! Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing `only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around 2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  17. Front End Spectroscopy ASIC for Germanium Detectors

    Science.gov (United States)

    Wulf, Eric

    Large-area, tracking, semiconductor detectors with excellent spatial and spectral resolution enable exciting new access to soft (0.2-5 MeV) gamma-ray astrophysics. The improvements from semiconductor tracking detectors come with the burden of high density of strips and/or pixels that require high-density, low-power, spectroscopy quality readout electronics. CMOS ASIC technologies are a natural fit to this requirement and have led to high-quality readout systems for all current semiconducting tracking detectors except for germanium detectors. The Compton Spectrometer and Imager (COSI), formerly NCT, at University of California Berkeley and the Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) at Goddard Space Flight Center utilize germanium cross-strip detectors and are on the forefront of NASA's Compton telescope research with funded missions of long duration balloon flights. The development of a readout ASIC for germanium detectors would allow COSI to replace their discrete electronics readout and would enable the proposed Gamma-Ray Explorer (GRX) mission utilizing germanium strip-detectors. We propose a 3-year program to develop and test a germanium readout ASIC to TRL 5 and to integrate the ASIC readout onto a COSI detector allowing a TRL 6 demonstration for the following COSI balloon flight. Our group at NRL led a program, sponsored by another government agency, to produce and integrate a cross-strip silicon detector ASIC, designed and fabricated by Dr. De Geronimo at Brookhaven National Laboratory. The ASIC was designed to handle the large (>30 pF) capacitance of three 10 cm^2 detectors daisy-chained together. The front-end preamplifier, selectable inverter, shaping times, and gains make this ASIC compatible with a germanium cross-strip detector as well. We therefore have the opportunity and expertise to leverage the previous investment in the silicon ASIC for a new mission. A germanium strip detector ASIC will also require precise timing of the signals at

  18. Circularly polarized light detector based on ferromagnet/semiconductor junctions

    CERN Document Server

    Ikeda, H; Nishibayashi, K; Munekata, H

    2014-01-01

    Helicity-dependent photocurrent delta-I has been detected successfully under experimental configuration that a circularly polarized light beam is impinged with a right angle on a cleaved sidewall of the Fe/x-AlOx/GaAs-based n-i-p double-heterostructure. The photocurrent delta-I has showed a well-defined hysteresis loop which resembles that of the magnetization of the in-plane magnetized Fe layer in the devices. The value of delta-I has been |delta-I|~0.2 nA at 5 K under the remnant magnetization state. Study on temperature dependence of the relative delta-I value at H = 0 has revealed that it is maximized at temperatures 125 - 150 K, and is still measurable at room temperature.

  19. Large area radiation detectors based on II VI thin films

    Science.gov (United States)

    Quevedo-Lopez, Manuel

    2015-03-01

    The development of low temperature device technologies that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible, low metal content, sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, neutron/gamma-ray/x-ray detectors, etc. In this talk, our efforts to develop novel CMOS integration schemes, circuits, memory, sensors as well as novel contacts, dielectrics and semiconductors for flexible electronics are presented. In particular, in this presentation we discuss fundamental materials properties including crystalline structure, interfacial reactions, doping, etc. defining performance and reliability of II-VI-based radiation sensors. We investigate the optimal thickness of a semiconductor diode for thin-film solid state thermal neutron detectors. Besides II-VI materials, we also evaluated several diode materials, Si, CdTe,GaAs, C (diamond), and ZnO, and two neutron converter materials,10B and 6LiF. We determine the minimum semiconductor thickness needed to achieve maximum neutron detection efficiency. By keeping the semiconductor thickness to a minimum, gamma rejection is kept as high as possible. In this way, we optimize detector performance for different thin-film semiconductor materials.

  20. Design of analog-to-digital converters for energy sensitive hybrid pixel detectors

    NARCIS (Netherlands)

    San Segundo Bello, David; Nauta, Bram; Visschers, Jan

    2001-01-01

    An important feature of hybrid semiconductor pixel detectors is the fact that detector and readout electronics are manufactured separately, allowing the use of industrial state-of-the-art CMOS processes to manufacture the readout electronics. As the feature size of these processes decreases, faster

  1. New optical technique for bulk magnetostriction measurement

    CERN Document Server

    Samata, H; Uchida, T; Abe, S

    2000-01-01

    A new optical technique was applied to the measurement of magnetostriction in bulk samples. This technique utilizes an optical fiber bundle, AC-modulated light and lock-in detection. Deformation of the sample is determined from the ratio of the incident and reflected light intensities. Noise due to the instability of the light source is eliminated by obtaining the ratio of the incident and reflected light intensities, and the noise caused in the detector circuit can be reduced by lock-in detection. The performance of this method was characterized with a series of measurements using a gold film and crystal disks of pure iron and nickel. This technique offers a resolution of 0.5 nm and is sensitive enough to measure magnetostriction as small as 5x10 sup - sup 7 in 1 mm thick samples.

  2. Electrodes for Semiconductor Gas Sensors.

    Science.gov (United States)

    Lee, Sung Pil

    2017-03-25

    The electrodes of semiconductor gas sensors are important in characterizing sensors based on their sensitivity, selectivity, reversibility, response time, and long-term stability. The types and materials of electrodes used for semiconductor gas sensors are analyzed. In addition, the effect of interfacial zones and surface states of electrode-semiconductor interfaces on their characteristics is studied. This study describes that the gas interaction mechanism of the electrode-semiconductor interfaces should take into account the interfacial zone, surface states, image force, and tunneling effect.

  3. Method of passivating semiconductor surfaces

    Science.gov (United States)

    Wanlass, Mark W.

    1990-01-01

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  4. Charged particle detection in organic semiconductors

    CERN Document Server

    Beckerle, P

    2000-01-01

    Polyacetylene is an organic semiconductor in which charges can be set free by a traversing charged particle, transported by an electric field to read-out electrodes and, subsequently, amplified and recorded in a way similar to what happens in a silicon-drift detector. In an experimental investigation of the features of this charge transport in thin foils we find drift velocities of the order of 40 cm/s. Stretching of the foils by a factor of three to four increases the drift velocity by a factor of ten and introduces a strong directionality of the charge transport. The detection efficiency of 5 MeV alpha particles in a few micron thin stretched foil is around 70%.

  5. Hydrogen in semiconductors

    CERN Document Server

    Pankove, Jacques I

    1991-01-01

    Hydrogen plays an important role in silicon technology, having a profound effect on a wide range of properties. Thus, the study of hydrogen in semiconductors has received much attention from an interdisciplinary assortment of researchers. This sixteen-chapter volume provides a comprehensive review of the field, including a discussion of hydrogenation methods, the use of hydrogen to passivate defects, the use of hydrogen to neutralize deep levels, shallow acceptors and shallow donors in silicon, vibrational spectroscopy, and hydrogen-induced defects in silicon. In addition to this detailed cove

  6. Physics of Organic Semiconductors

    CERN Document Server

    Brütting, Wolfgang

    2005-01-01

    Filling the gap in the literature currently available, this book presents an overview of our knowledge of the physics behind organic semiconductor devices. Contributions from 18 international research groups cover various aspects of this field, ranging from the growth of organic layers and crystals, their electronic properties at interfaces, their photophysics and electrical transport properties to the application of these materials in such different devices as organic field-effect transistors, photovoltaic cells and organic light-emitting diodes. From the contents:. * Excitation Dynamics in O

  7. Semiconductor microcavity polaritons

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, Evgenii A [Institute of Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow region (Russian Federation)

    2002-12-31

    The optical properties of wide-gap semiconductor films on metal substrates were investigated experimentally by infrared spectroscopy, Raman scattering, and femtosecond spectroscopy techniques as well as theoretically in the framework of linear crystal optics. The optical spectra of such planar structures (microresonators) were shown to bear information on electromagnetic excitations of both the surface and the volume of the structure. The optical spectra are determined by the interaction of all dipole-active excitations of the component materials with the electromagnetic modes of the microresonator, which in turn are determined by the permittivities of each component material, microcavity (microresonator) thickness, and the experimental conditions. (reviews of topical problems)

  8. Electrowetting on semiconductors

    Science.gov (United States)

    Palma, Cesar; Deegan, Robert

    2015-01-01

    Applying a voltage difference between a conductor and a sessile droplet sitting on a thin dielectric film separating it from the conductor will cause the drop to spread. When the conductor is a good metal, the change of the drop's contact angle due to the voltage is given by the Young-Lippmann (YL) equation. Here, we report experiments with lightly doped, single crystal silicon as the conductive electrode. We derive a modified YL equation that includes effects due to the semiconductor and contact line pinning. We show that light induces a non-reversible wetting transition, and that our model agrees well with our experimental results.

  9. Band structure of semiconductors

    CERN Document Server

    Tsidilkovski, I M

    2013-01-01

    Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

  10. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-09-15

    Contrary to other claims, we argue that bulk viscosity associated with the interactions of non- relativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk-viscosity effects of a weakly interacting mixture of relativistic and nonrelativistic particles.

  11. Brane Couplings from Bulk Loops

    OpenAIRE

    Georgi, Howard; Grant, Aaron K.; Hailu, Girma

    2000-01-01

    We compute loop corrections to the effective action of a field theory on a five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings.

  12. Semiconductor devices incorporating multilayer interference regions

    Science.gov (United States)

    Biefeld, Robert M.; Drummond, Timothy J.; Gourley, Paul L.; Zipperian, Thomas E.

    1990-01-01

    A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration.

  13. Single photonics at telecom wavelengths using nanowire superconducting detectors

    CERN Document Server

    Zinoni, C; Fiore, A; Gerardino, A; Goltsman, G N; Li, L H; Lunghi, L; Marsili, F; Smirnov, K V; Vakhtomin, Y B; Vakhtomin, Yu. B.

    2006-01-01

    Single photonic applications - such as quantum key distribution - rely on the transmission of single photons, and require the ultimate sensitivity that an optical detector can achieve. Single-photon detectors must convert the energy of an optical pulse containing a single photon into a measurable electrical signal. We report on fiber-coupled superconducting single-photon detectors (SSPDs) with specifications that exceed those of avalanche photodiodes (APDs), operating at telecommunication wavelength, in sensitivity, temporal resolution and repetition frequency. The improved performance is demonstrated by measuring the intensity correlation function g(2)(t) of single-photon states at 1300nm produced by single semiconductor quantum dots (QDs).

  14. Photoelectron spectroscopy bulk and surface electronic structures

    CERN Document Server

    Suga, Shigemasa

    2014-01-01

    Photoelectron spectroscopy is now becoming more and more required to investigate electronic structures of various solid materials in the bulk, on surfaces as well as at buried interfaces. The energy resolution was much improved in the last decade down to 1 meV in the low photon energy region. Now this technique is available from a few eV up to 10 keV by use of lasers, electron cyclotron resonance lamps in addition to synchrotron radiation and X-ray tubes. High resolution angle resolved photoelectron spectroscopy (ARPES) is now widely applied to band mapping of materials. It attracts a wide attention from both fundamental science and material engineering. Studies of the dynamics of excited states are feasible by time of flight spectroscopy with fully utilizing the pulse structures of synchrotron radiation as well as lasers including the free electron lasers (FEL). Spin resolved studies also made dramatic progress by using higher efficiency spin detectors and two dimensional spin detectors. Polarization depend...

  15. Squeezed light in semiconductors

    CERN Document Server

    Ward, M B

    2001-01-01

    Experimental evidence is presented for the generation of photon-number squeezed states of light as a result of multi-photon absorption. Photon-number squeezing as a result of non-linear absorption has long been predicted and results have been obtained utilising two very different material systems: (i) an AIGaAs waveguide in which high optical intensities can be maintained over a relatively long interaction length of 2 mm; (ii) the organic polymer p-toluene sulphonate polydiacetylene that is essentially a one-dimensional semiconductor possessing a highly nonlinear optical susceptibility. The resulting nonlinear absorption is shown to leave the transmitted light in a state that is clearly nonclassical, exhibiting photon-number fluctuations below the shot-noise limit. Tuning the laser wavelength across the half-bandgap energy has enabled a comparison between two- and three-photon processes in the semiconductor waveguide. The correlations created between different spectral components of a pulsed beam of light as ...

  16. Doped semiconductor nanocrystal junctions

    Energy Technology Data Exchange (ETDEWEB)

    Borowik, Ł.; Mélin, T., E-mail: thierry.melin@isen.iemn.univ-lille1.fr [Institut d’Electronique, de Microélectronique et de Nanotechnologie, CNRS-UMR8520, Avenue Poincaré, F-59652 Villeneuve d’Ascq (France); Nguyen-Tran, T.; Roca i Cabarrocas, P. [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS-UMR7647, Ecole Polytechnique, F-91128 Palaiseau (France)

    2013-11-28

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (N{sub D}≈10{sup 20}−10{sup 21}cm{sup −3}) silicon nanocrystals (NCs) in the 2–50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as N{sub D}{sup −1/3}, and depleted charge linearly increasing with the NC diameter and varying as N{sub D}{sup 1/3}. We thus establish a “nanocrystal counterpart” of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

  17. Hydrogen molecules in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Joerg [Technische Universitaet Dresden, 01062 Dresden (Germany)], E-mail: joerg.weber@tu-dresden.de; Hiller, Martin; Lavrov, Edward V. [Technische Universitaet Dresden, 01062 Dresden (Germany)

    2007-12-15

    Molecular hydrogen, the simplest of all molecules, allows a direct insight into the fundamental properties of quantum mechanics. In the case of H{sub 2}, the Pauli principle leads to two different species, para-H{sub 2} and ortho-H{sub 2}. A conversion between these species is prohibited. Vibrational mode spectra reflect the fundamental properties and allow an unambiguous identification of the H{sub 2} molecules. Today, we have experimental evidence for the trapping of hydrogen molecules in the semiconductors Si, Ge and GaAs at the interstitial sites, within hydrogen-induced platelets, in voids and at impurities (interstitial oxygen in Si). Interstitial H{sub 2} is a nearly free rotor with a surprisingly simple behavior. We review on interstitial H{sub 2} in semiconductors and report on the unexpected preferential disappearance of the para-H{sub 2} or ortho-D{sub 2} species. The origin of the detected ortho-para conversion will be discussed.

  18. Gating a ferromagnetic semiconductor

    Science.gov (United States)

    Bove, A.; Altomare, F.; Kundtz, N.; Chang, A. M.; Cho, Y. J.; Liu, X.; Furdyna, J.

    2007-03-01

    Ferromagnetic semiconductors have the potential of revolutionizing the way current electronic devices work: more so, because they are compatible with current fabrication lines and can easily be integrated with today's technology. Particular interest lies in III-V Diluted Magnetic Semiconductor (DMS), where the ferromagnetism is hole-mediated and the Curie temperature can therefore be tuned by changing the concentration of free carriers. In these systems, most of the effort is currently applied toward the fabrication of devices working at room-temperature: this implies high carrier density accompanied by low mobility and short mean free path. We will report our results for a ferromagnetic 2DHG system with low carrier density (˜3.4E12 cm-2) and mobility (˜ 1000 cm^2/(Vs)), and we will discuss the effects of local gating in light of possible applications to the fabrication of ferromagnetic quantum dots. T. Dietl et al., Phys. Rev. B 63, 195205 (2001). H. Ohno et al., Nature 408, 944 (2000)

  19. Characteristics of the ATLAS and CMS detectors

    CERN Document Server

    Seiden, Abraham

    2012-01-01

    The goal for the detection of new physics processes in particle collisions at Large Hadron Collider energies, combined with the broad spectrum of possibilities for how the physics might be manifest, leads to detectors of unprecedented scope and size for particle physics experiments at colliders. The resulting two detectors, ATLAS (A Toroidal LHC ApparatuS) and CMS (compact muon spectrometer), must search for the new physics processes within very complex events arising from the very high-energy collisions. The two experiments share many basic design features—in particular, the need for very selective triggering to weed out the bulk of the uninteresting events; the order in which detector types are arrayed in order to provide maximum information about each event; and the very large angular coverage required to constrain the energy carried by any non-interacting particles. However, within these basic constraints, the detectors are quite different given the different emphases placed on issues such as resolution...

  20. Semiconductor nanostructures in biological applications

    Energy Technology Data Exchange (ETDEWEB)

    Alexson, Dimitri [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Chen Hongfeng [Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Cho, Michael [Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Department of Physics, University of Illinois at Chicago, Chicago, IL 60607 (United States); Dutta, Mitra [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Department of Physics, University of Illinois at Chicago, Chicago, IL 60607 (United States); Li Yang [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Shi, Peng [Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Raichura, Amit [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Ramadurai, Dinakar [Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Parikh, Shaunak [Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Stroscio, Michael A [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Department of Physics, University of Illinois at Chicago, Chicago, IL 60607 (United States); Vasudev, Milana [Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607 (United States)

    2005-07-06

    Semiconductor nanostructures in biological applications are discussed. Results are presented on the use of colloidal semiconductor quantum dots both as biological tags and as structures that interact with and influence biomolecules. Results are presented on the use of semiconducting carbon nanotubes in biological applications. (topical review)

  1. Variable temperature semiconductor film deposition

    Science.gov (United States)

    Li, Xiaonan; Sheldon, Peter

    1998-01-01

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

  2. Optical coherent control in semiconductors

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Vadim, Lyssenko; Hvam, Jørn Märcher

    2001-01-01

    of quantum control including the recent applications to semiconductors and nanostructures. We study the influence of inhomogeneous broadening in semiconductors on CC results. Photoluminescence (PL) and the coherent emission in four-wave mixing (FWM) is recorded after resonant excitation with phase...

  3. II-VI semiconductor compounds

    CERN Document Server

    1993-01-01

    For condensed matter physicists and electronic engineers, this volume deals with aspects of II-VI semiconductor compounds. Areas covered include devices and applications of II-VI compounds; Co-based II-IV semi-magnetic semiconductors; and electronic structure of strained II-VI superlattices.

  4. Semiconductor photocatalysis principles and applications

    CERN Document Server

    Kisch, Horst

    2014-01-01

    Focusing on the basic principles of semiconductor photocatalysis, this book also gives a brief introduction to photochemistry, photoelectrochemistry, and homogeneous photocatalysis. In addition, the author - one of the leading authorities in the field - presents important environmental and practical aspects. A valuable, one-stop source for all chemists, material scientists, and physicists working in this area, as well as novice researchers entering semiconductor photocatalysis.

  5. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  6. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  7. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    Science.gov (United States)

    Lopez-Varo, Pilar; Bertoluzzi, Luca; Bisquert, Juan; Alexe, Marin; Coll, Mariona; Huang, Jinsong; Jimenez-Tejada, Juan Antonio; Kirchartz, Thomas; Nechache, Riad; Rosei, Federico; Yuan, Yongbo

    2016-10-01

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron-hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  8. Organic semiconductors in a spin

    CERN Document Server

    Samuel, I

    2002-01-01

    A little palladium can go a long way in polymer-based light-emitting diodes. Inorganic semiconductors such as silicon and gallium arsenide are essential for countless applications in everyday life, ranging from PCs to CD players. However, while they offer unrivalled computational speed, inorganic semiconductors are also rigid and brittle, which means that they are less suited to applications such as displays and flexible electronics. A completely different class of materials - organic semiconductors - are being developed for these applications. Organic semiconductors have many attractive features: they are easy to make, they can emit visible light, and there is tremendous scope for tailoring their properties to specific applications by changing their chemical structure. Research groups and companies around the world have developed a wide range of organic-semiconductor devices, including transistors, light-emitting diodes (LEDs), solar cells and lasers. (U.K.)

  9. Semiconductors for Plasmonics and Metamaterials

    CERN Document Server

    Naik, Gururaj V; 10.1002/pssr.201004269

    2011-01-01

    Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals with semiconductors can alleviate these problems if only semiconductors could exhibit negative real permittivity. Aluminum doped zinc oxide (AZO) is a low loss semiconductor that can show negative real permittivity in the NIR. A comparative assessment of AZO-based plasmonic devices such as superlens and hyperlens with their metal-based counterparts shows that AZO-based devices significantly outperform at a wavelength of 1.55 um. This provides a strong stimulus in turning to semiconductor plasmonics at the telecommunication wavelengths.

  10. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  11. Multistability, chaos, and random signal generation in semiconductor superlattices

    Science.gov (United States)

    Ying, Lei; Huang, Danhong; Lai, Ying-Cheng

    2016-06-01

    Historically, semiconductor superlattices, artificial periodic structures of different semiconductor materials, were invented with the purpose of engineering or manipulating the electronic properties of semiconductor devices. A key application lies in generating radiation sources, amplifiers, and detectors in the "unusual" spectral range of subterahertz and terahertz (0.1-10 THz), which cannot be readily realized using conventional radiation sources, the so-called THz gap. Efforts in the past three decades have demonstrated various nonlinear dynamical behaviors including chaos, suggesting the potential to exploit chaos in semiconductor superlattices as random signal sources (e.g., random number generators) in the THz frequency range. We consider a realistic model of hot electrons in semiconductor superlattice, taking into account the induced space charge field. Through a systematic exploration of the phase space we find that, when the system is subject to an external electrical driving of a single frequency, chaos is typically associated with the occurrence of multistability. That is, for a given parameter setting, while there are initial conditions that lead to chaotic trajectories, simultaneously there are other initial conditions that lead to regular motions. Transition to multistability, i.e., the emergence of multistability with chaos as a system parameter passes through a critical point, is found and argued to be abrupt. Multistability thus presents an obstacle to utilizing the superlattice system as a reliable and robust random signal source. However, we demonstrate that, when an additional driving field of incommensurate frequency is applied, multistability can be eliminated, with chaos representing the only possible asymptotic behavior of the system. In such a case, a random initial condition will lead to a trajectory landing in a chaotic attractor with probability 1, making quasiperiodically driven semiconductor superlattices potentially as a reliable

  12. Cosmic Ray Measurements by Scintillators with Metal Resistor Semiconductor Avalanche Photo Diodes

    Science.gov (United States)

    Blanco, Francesco; La Rocca, Paola; Riggi, Francesco; Akindinov, Alexandre; Mal'kevich, Dmitry

    2008-01-01

    An educational set-up for cosmic ray physics experiments is described. The detector is based on scintillator tiles with a readout through metal resistor semiconductor (MRS) avalanche photo diode (APD) arrays. Typical measurements of the cosmic angular distribution at sea level and a study of the East-West asymmetry obtained by such a device are…

  13. RD50 Status Report 2008 - Radiation hard semiconductor devices for very high luminosity colliders

    CERN Document Server

    Balbuena, Juan Pablo; Campabadal, Francesca; Díez, Sergio; Fleta, Celeste; Lozano, Manuel; Pellegrini, Giulio; Rafí, Joan Marc; Ullán, Miguel; Creanza, Donato; De Palma, Mauro; Fedele, Francesca; Manna, Norman; Kierstead, Jim; Li, Zheng; Buda, Manuela; Lazanu, Sorina; Pintilie, Lucian; Pintilie, Ioana; Popa, Andreia-Ioana; Lazanu, Ionel; Collins, Paula; Fahrer, Manuel; Glaser, Maurice; Joram, Christian; Kaska, Katharina; La Rosa, Alessandro; Mekki, Julien; Moll, Michael; Pacifico, Nicola; Pernegger, Heinz; Goessling, Claus; Klingenberg, Reiner; Weber, Jens; Wunstorf, Renate; Roeder, Ralf; Stolze, Dieter; Uebersee, Hartmut; Cihangir, Selcuk; Kwan, Simon; Spiegel, Leonard; Tan, Ping; Bruzzi, Mara; Focardi, Ettore; Menichelli, David; Scaringella, Monica; Breindl, Michael; Eckert, Simon; Köhler, Michael; Kuehn, Susanne; Parzefall, Ulrich; Wiik, Liv; Bates, Richard; Blue, Andrew; Buttar, Craig; Doherty, Freddie; Eklund, Lars; Bates, Alison G; Haddad, Lina; Houston, Sarah; James, Grant; Mathieson, Keith; Melone, J; OShea, Val; Parkes, Chris; Pennicard, David; Buhmann, Peter; Eckstein, Doris; Fretwurst, Eckhart; Hönniger, Frank; Khomenkov, Vladimir; Klanner, Robert; Lindström, Gunnar; Pein, Uwe; Srivastava, Ajay; Härkönen, Jaakko; Lassila-Perini, Katri; Luukka, Panja; Mäenpää, Teppo; Tuominen, Eija; Tuovinen, Esa; Eremin, Vladimir; Ilyashenko, Igor; Ivanov, Alexandr; Kalinina, Evgenia; Lebedev, Alexander; Strokan, Nikita; Verbitskaya, Elena; Barcz, Adam; Brzozowski, Andrzej; Kaminski, Pawel; Kozlowski, Roman; Kozubal, Michal; Luczynski, Zygmunt; Pawlowski, Marius; Surma, Barbara; Zelazko, Jaroslaw; de Boer, Wim; Dierlamm, Alexander; Frey, Martin; Hartmann, Frank; Zhukov, Valery; Barabash, L; Dolgolenko, A; Groza, A; Karpenko, A; Khivrich, V; Lastovetsky, V; Litovchenko, P; Polivtsev, L; Campbell, Duncan; Chilingarov, Alexandre; Fox, Harald; Hughes, Gareth; Jones, Brian Keith; Sloan, Terence; Samadashvili, Nino; Tuuva, Tuure; Affolder, Anthony; Allport, Phillip; Bowcock, Themis; Casse, Gianluigi; Vossebeld, Joost; Cindro, Vladimir; Dolenc, Irena; Kramberger, Gregor; Mandic, Igor; Mikuž, Marko; Zavrtanik, Marko; Zontar, Dejan; Gil, Eduardo Cortina; Grégoire, Ghislain; Lemaitre, Vincent; Militaru, Otilia; Piotrzkowski, Krzysztof; Kazuchits, Nikolai; Makarenko, Leonid; Charron, Sébastien; Genest, Marie-Helene; Houdayer, Alain; Lebel, Celine; Leroy, Claude; Aleev, Andrey; Golubev, Alexander; Grigoriev, Eugene; Karpov, Aleksey; Martemianov, Alxander; Rogozhkin, Sergey; Zaluzhny, Alexandre; Andricek, Ladislav; Beimforde, Michael; Macchiolo, Anna; Moser, Hans-Günther; Nisius, Richard; Richter, Rainer; Gorelov, Igor; Hoeferkamp, Martin; Metcalfe, Jessica; Seidel, Sally; Toms, Konstantin; Hartjes, Fred; Koffeman, Els; van der Graaf, Harry; Visschers, Jan; Kuznetsov, Andrej; Sundnes Løvlie, Lars; Monakhov, Edouard; Svensson, Bengt G; Bisello, Dario; Candelori, Andrea; Litovchenko, Alexei; Pantano, Devis; Rando, Riccardo; Bilei, Gian Mario; Passeri, Daniele; Petasecca, Marco; Pignatel, Giorgio Umberto; Bernardini, Jacopo; Borrello, Laura; Dutta, Suchandra; Fiori, Francesco; Messineo, Alberto; Bohm, Jan; Mikestikova, Marcela; Popule, Jiri; Sicho, Petr; Tomasek, Michal; Vrba, Vaclav; Broz, Jan; Dolezal, Zdenek; Kodys, Peter; Tsvetkov, Alexej; Wilhelm, Ivan; Chren, Dominik; Horazdovsky, Tomas; Kohout, Zdenek; Pospisil, Stanislav; Solar, Michael; Sopko, Vít; Sopko, Bruno; Uher, Josef; Horisberger, Roland; Radicci, Valeria; Rohe, Tilman; Bolla, Gino; Bortoletto, Daniela; Giolo, Kim; Miyamoto, Jun; Rott, Carsten; Roy, Amitava; Shipsey, Ian; Son, SeungHee; Demina, Regina; Korjenevski, Sergey; Grillo, Alexander; Sadrozinski, Hartmut; Schumm, Bruce; Seiden, Abraham; Spence, Ned; Hansen, Thor-Erik; Artuso, Marina; Borgia, Alessandra; Lefeuvre, Gwenaelle; Guskov, J; Marunko, Sergey; Ruzin, Arie; Tylchin, Tamir; Boscardin, Maurizio; Dalla Betta, Gian - Franco; Gregori, Paolo; Piemonte, Claudio; Ronchin, Sabina; Zen, Mario; Zorzi, Nicola; Garcia, Carmen; Lacasta, Carlos; Marco, Ricardo; Marti i Garcia, Salvador; Minano, Mercedes; Soldevila-Serrano, Urmila; Gaubas, Eugenijus; Kadys, Arunas; Kazukauskas, Vaidotas; Sakalauskas, Stanislavas; Storasta, Jurgis; Vidmantis Vaitkus, Juozas; CERN. Geneva. The LHC experiments Committee; LHCC

    2010-01-01

    The objective of the CERN RD50 Collaboration is the development of radiation hard semiconductor detectors for very high luminosity colliders, particularly to face the requirements of a possible upgrade scenario of the LHC.This document reports the status of research and main results obtained after the sixth year of activity of the collaboration.

  14. Ultrafast dephasing of interband transitions in semiconductors

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Haichao

    2001-01-01

    [1]Becker, P. C., Fragnito, H. L., Brito, C. C. H. et al., Femtosecond photon echoes from band-to-band transitions in GaAs, Phys. Rev. Lett., 1988, 61: 1647—1649.[2]Lin, W. Z., Schoenlein, R. W., Fujimoto, J. G. et al., Femtosecond absorption saturation of hot carriers in GaAs and AlGaAs, IEEE JQE, 1988, 24: 267—275.[3]Gurevich, V. L., Muradov, M. I., Parshin, D. A., On the theory of femtosecond photon echoes from band-to -band transitions in semiconductors, Europhys. Lett., 1990, 12(4): 375—379.[4]Sayed, K. E., Bányai, L., Haug, H., Coulomb quantum kinetics and optical dephasing on the femtosecond time scale, Phys. Rev. B, 1994, 50:1541—1550.[5]Arlt, S., Siegner, U., Kunde, J. et al., Ultrafast dephasing of continuum transitions in bulk semiconductors, Phys. Rev. B, 1999, 59: 14860—14863.[6]Hügel, W. A., Heinrich, M. F., Wegener, M. et al., Photon echoes from semiconductor band-to -band continuum transitions in the regime of Coulomb quantum kinetics, Phys. Rev. Lett., 1999, 83(16): 3313—3316.[7]Scott, D. C., Binder, R., Koch, S. W., Ultrafast dephasing through acoustic plasmon undamping in nonequilibrium electron-hole plasmas, Phys. Rev. Lett., 1992, 69(2): 347—350.[8]Binder, R., Scott, D., Paul, A. E. et al., Carrier-carrier scattering and optical dephasing in highly excited semiconductors, Phys. Rev., B 1991, 45: 1107—1114.[9]Schilp, J., Kuhn, T., Mahler, G., Electron-phonon quantum kinetics in pulse-excited semiconductors: Memory and renormalization effects, Phys. Rev. B, 1994, 50: 5435—5447.[10]Snoke, D. W., Density dependence of electron scattering at low density, Phys. Rev., B 1994, 50: 11583—11591.[11]Leitenstorfer, A., Lohner, A., Rick, K. et al., Excitonic and free-carrier polarizations of bulk GaAs studied by femtosecond coherent spectroscopy, Phys. Rev., 1994B 49: 16372—16380.[12]Zhang, H. C., Wen, J. H., Guo, B. Hole-hole scattering of photoexcited heavy-holes in GaAs, Acta Physica

  15. Processing of Complex Compound Semiconductors in Space

    Science.gov (United States)

    Bachmann, K.

    1985-01-01

    The purpose of this first year ground based research effort was to develop growth and characterization facilities for bulk single crystals of compound semiconductor alloys. As a system of 2-6 alloy crystal growth, C sub x Mn sub (1-x)Te was chosen since it has a relatively narrow solidus-liquidus separation serving as a suitable first model for zone melting and solution growth. Also, it allows, in principle, perfect lattice matching to Cd sub x Hg sub(1-x)Te that needs to be studied as a model for the investigation of heteroepitaxial growth from Te-solutions. A vertical zone melting furnace was built and used in the synthesis of Cd sub x Mn sub(1-x)Te from the elements and crystal growth in carbon coated fused silica crucibles of Bridgman growth geometry. Photoluminescence spectra of the crystals reveal band to band recombination at energies that agree with the reported literature data. In addition, deep luminescence is present at energies corresponding to proportional shifts from the 1.4 eV deep emission observed for bulk single crystals of CdTe.

  16. The ATLAS Semiconductor tracker: operations and performance

    CERN Document Server

    Pani, P; The ATLAS collaboration

    2013-01-01

    Tracker After more than 3 years of successful operation at the LHC, we report on the operation and performance of the Semi-Conductor Tracker (SCT) functioning in a high luminosity, high radiation environment. The SCT is part of the ATLAS experiment at CERN and is constructed of 4088 silicon detector modules for a total of 6.3 million strips. Each module is designed, constructed and tested to operate as a stand-alone unit, mechanically, electrically, optically and thermally. The modules are mounted into two types of structures: one barrel (4 cylinders) and two end-cap systems (9 disks on each end of the barrel). The SCT silicon micro-strip sensors are processed in the planar p-in-n technology. The signals are processed in the front-end ABCD3TA ASICs, which use a binary readout architecture. Data is transferred to the off-detector readout electronics via optical fibers. We find 99.3% of the SCT modules are operational, noise occupancy and hit efficiency exceed the design specifications; the alignment is very cl...

  17. X-Ray and Gamma-Ray Radiation Detector

    DEFF Research Database (Denmark)

    2015-01-01

    Disclosed is a semiconductor radiation detector for detecting X-ray and / or gamma-ray radiation. The detector comprises a converter element for converting incident X-ray and gamma-ray photons into electron-hole pairs, at least one cathode, a plurality of detector electrodes arranged with a pitch...... (P) along a first axis, a plurality of drift electrodes, a readout circuitry being configured to read out signals from the plurality of detector electrodes and a processing unit connected to the readout circuitry and being configured to detect an event in the converter element. The readout circuitry...... is further configured to read out signals from the plurality of drift electrodes, and the processing unit is further configured to estimate a location of the event along the first axis by processing signals obtained from both the detector electrodes and the drift electrodes, the location of the event along...

  18. MC-128 current commutator for silicon strip detector tests

    CERN Document Server

    Anghinolfi, Francis; Chilingarov, A G; Kollegov, M; Ledenev, E K A; Ledenev, E Kuper A

    1996-01-01

    The MC-128 is a CAMAC module designed to simplify routine tests of multichannel semiconductor detectors. It was developed at Budker Institute of Nuclear Physics (BINP) Novosibirsk in collaboration with RD2 as part of the ATLAS SCT development program. The module provides 128 channels, offering sequential measurements of the currents flowing grom detector strips to a grounded Common Bus. Each input stays virtually connected to the Common Bus independently on whether its current is measured or not. Eight inputs are permanently connected to the Common Bus, allowing the connection of additional elements like guard ring structures. The total detector current can be measured as the current flowing through the Common Bus. Measurements are accessible via a CAMAC bus and in analog form via a front panel detector. Optionally, the MC 128 allows the measurement of the capacitance between each strip and the common (high voltage) electrode of the detector at 10 kHz frequency.

  19. Vertex detectors: The state of the art and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Damerell, C.J.S. [Rutherford Appleton Laboratory, Didcot (United Kingdom)

    1997-01-01

    We review the current status of vertex detectors (tracking microscopes for the recognition of charm and bottom particle decays). The reasons why silicon has become the dominant detector medium are explained. Energy loss mechanisms are reviewed, as well as the physics and technology of semiconductor devices, emphasizing the areas of most relevance for detectors. The main design options (microstrips and pixel devices, both CCD`s and APS`s) are discussed, as well as the issue of radiation damage, which probably implies the need to change to detector media beyond silicon for some vertexing applications. Finally, the evolution of key performance parameters over the past 15 years is reviewed, and an attempt is made to extrapolate to the likely performance of detectors working at the energy frontier ten years from now.

  20. Semiconductor nanowire lasers

    Science.gov (United States)

    Eaton, Samuel W.; Fu, Anthony; Wong, Andrew B.; Ning, Cun-Zheng; Yang, Peidong

    2016-06-01

    The discovery and continued development of the laser has revolutionized both science and industry. The advent of miniaturized, semiconductor lasers has made this technology an integral part of everyday life. Exciting research continues with a new focus on nanowire lasers because of their great potential in the field of optoelectronics. In this Review, we explore the latest advancements in the development of nanowire lasers and offer our perspective on future improvements and trends. We discuss fundamental material considerations and the latest, most effective materials for nanowire lasers. A discussion of novel cavity designs and amplification methods is followed by some of the latest work on surface plasmon polariton nanowire lasers. Finally, exciting new reports of electrically pumped nanowire lasers with the potential for integrated optoelectronic applications are described.

  1. Semiconductor adiabatic qubits

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Malcolm S.; Witzel, Wayne; Jacobson, Noah Tobias; Ganti, Anand; Landahl, Andrew J.; Lilly, Michael; Nguyen, Khoi Thi; Bishop, Nathaniel; Carr, Stephen M.; Bussmann, Ezra; Nielsen, Erik; Levy, James Ewers; Blume-Kohout, Robin J.; Rahman, Rajib

    2016-12-27

    A quantum computing device that includes a plurality of semiconductor adiabatic qubits is described herein. The qubits are programmed with local biases and coupling terms between qubits that represent a problem of interest. The qubits are initialized by way of a tuneable parameter, a local tunnel coupling within each qubit, such that the qubits remain in a ground energy state, and that initial state is represented by the qubits being in a superposition of |0> and |1> states. The parameter is altered over time adiabatically or such that relaxation mechanisms maintain a large fraction of ground state occupation through decreasing the tunnel coupling barrier within each qubit with the appropriate schedule. The final state when tunnel coupling is effectively zero represents the solution state to the problem represented in the |0> and |1> basis, which can be accurately read at each qubit location.

  2. A semiconductor based electrode

    Energy Technology Data Exchange (ETDEWEB)

    Khamatani, A.; Kobayasi, K.

    1983-03-30

    The semiconductor electrode is submerged into an electrolyte which is held in the illuminated chamber. The other electrode is placed in a dark chamber connected with the channel to be illuminated, which has a partition in the form of a membrane. An electric current flows in the external circuit of the element with illumination of the first electrode. The illuminated electrode is covered with a thin film of a substance which is stable with the action of the electrolyte. The film is made of Si02, A1203, GaN or A1N. The protective coating makes it possible to use materials less stable than Ti02 in a rutile modification, but which have higher characteristics than the GaP, GaAs, CdS and InP, for making the electrode.

  3. Type II superlattice technology for LWIR detectors

    Science.gov (United States)

    Klipstein, P. C.; Avnon, E.; Azulai, D.; Benny, Y.; Fraenkel, R.; Glozman, A.; Hojman, E.; Klin, O.; Krasovitsky, L.; Langof, L.; Lukomsky, I.; Nitzani, M.; Shtrichman, I.; Rappaport, N.; Snapi, N.; Weiss, E.; Tuito, A.

    2016-05-01

    SCD has developed a range of advanced infrared detectors based on III-V semiconductor heterostructures grown on GaSb. The XBn/XBp family of barrier detectors enables diffusion limited dark currents, comparable with MCT Rule-07, and high quantum efficiencies. This work describes some of the technical challenges that were overcome, and the ultimate performance that was finally achieved, for SCD's new 15 μm pitch "Pelican-D LW" type II superlattice (T2SL) XBp array detector. This detector is the first of SCD's line of high performance two dimensional arrays working in the LWIR spectral range, and was designed with a ~9.3 micron cut-off wavelength and a format of 640 x 512 pixels. It contains InAs/GaSb and InAs/AlSb T2SLs, engineered using k • p modeling of the energy bands and photo-response. The wafers are grown by molecular beam epitaxy and are fabricated into Focal Plane Array (FPA) detectors using standard FPA processes, including wet and dry etching, indium bump hybridization, under-fill, and back-side polishing. The FPA has a quantum efficiency of nearly 50%, and operates at 77 K and F/2.7 with background limited performance. The pixel operability of the FPA is above 99% and it exhibits a stable residual non uniformity (RNU) of better than 0.04% of the dynamic range. The FPA uses a new digital read-out integrated circuit (ROIC), and the complete detector closely follows the interfaces of SCD's MWIR Pelican-D detector. The Pelican- D LW detector is now in the final stages of qualification and transfer to production, with first prototypes already integrated into new electro-optical systems.

  4. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-04-01

    Contrary to other claims, we argue that, bulk viscosity associated with the interactions of nonrelativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk viscosity effects of a weakly-interacting mixture of relativistic and nonrelativistic particles. 13 refs., 1 fig.

  5. A 77 K MOS magnetic field detector

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, R S; Torres, A. [Instituto Nacional de Astrofisica Optica y Electronica, Puebla (Mexico); Garcia, P.J. [Universidad Veracruzana, Veracruz (Mexico); Gutierrez, E.A. [Motorola, Puebla (Mexico)

    2001-12-01

    An integrated MOS (metal-oxide-semiconductor)-compatible magnetic field detector (split-drain MAGFET) for operation at liquid-nitrogen temperature LNT (77 K) is presented. The measured relative magnetic sensibility (S{sub a}) is approximately 14%/T (double the value ever reported) using a non-optimized MAGFET structure (W/L) = (100 mm/125 mm). The cryo-magnetic structure was tested without a built-in preamplifier. It presents a power consumption of the order of mW. [Spanish] A traves de este articulo se presenta un detector de campo magnetico (split-drain MAGFET), basado en el transistor de efecto de campo MOS (metal-oxido-semiconductor), y totalmente compatible con procesos de fabricacion de circuitos integrados CMOS. La operacion optima de este detector es a temperaturas criogenicas. Aqui se presentan los resultados experimentales de la caracterizacion de una estructura no optimizada con dimensiones (W / L) = (100 mm/125 mm) a la temperatura del nitrogeno liquido (77 K). La sensibilidad relativa medida es de cerca del 14 % T, casi el doble del valor maximo antes reportado en la literatura. El dispositivo se midio sin un pre-amplificador integrado, mostrando un consumo de potencia del orden de microwatts.

  6. Semiconductor Nanocrystals for Biological Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Aihua; Gu, Weiwei; Larabell, Carolyn; Alivisatos, A. Paul

    2005-06-28

    Conventional organic fluorophores suffer from poor photo stability, narrow absorption spectra and broad emission feature. Semiconductor nanocrystals, on the other hand, are highly photo-stable with broad absorption spectra and narrow size-tunable emission spectra. Recent advances in the synthesis of these materials have resulted in bright, sensitive, extremely photo-stable and biocompatible semiconductor fluorophores. Commercial availability facilitates their application in a variety of unprecedented biological experiments, including multiplexed cellular imaging, long-term in vitro and in vivo labeling, deep tissue structure mapping and single particle investigation of dynamic cellular processes. Semiconductor nanocrystals are one of the first examples of nanotechnology enabling a new class of biomedical applications.

  7. One-Dimensional Nanostructures and Devices of II–V Group Semiconductors

    Directory of Open Access Journals (Sweden)

    Shen Guozhen

    2009-01-01

    Full Text Available Abstract The II–V group semiconductors, with narrow band gaps, are important materials with many applications in infrared detectors, lasers, solar cells, ultrasonic multipliers, and Hall generators. Since the first report on trumpet-like Zn3P2nanowires, one-dimensional (1-D nanostructures of II–V group semiconductors have attracted great research attention recently because these special 1-D nanostructures may find applications in fabricating new electronic and optoelectronic nanoscale devices. This article covers the 1-D II–V semiconducting nanostructures that have been synthesized till now, focusing on nanotubes, nanowires, nanobelts, and special nanostructures like heterostructured nanowires. Novel electronic and optoelectronic devices built on 1-D II–V semiconducting nanostructures will also be discussed, which include metal–insulator-semiconductor field-effect transistors, metal-semiconductor field-effect transistors, andp–nheterojunction photodiode. We intent to provide the readers a brief account of these exciting research activities.

  8. Semiconductor with protective surface coating and method of manufacture thereof. [Patent application

    Science.gov (United States)

    Hansen, W.L.; Haller, E.E.

    1980-09-19

    Passivation of predominantly crystalline semiconductor devices is provided for by a surface coating of sputtered hydrogenated amorphous semiconductor material. Passivation of a radiation detector germanium diode, for example, is realized by sputtering a coating of amorphous germanium onto the etched and quenched diode surface in a low pressure atmosphere of hydrogen and argon. Unlike prior germanium diode semiconductor devices, which must be maintained in vacuum at cryogenic temperatures to avoid deterioration, a diode processed in the described manner may be stored in air at room temperature or otherwise exposed to a variety of environmental conditions. The coating compensates for pre-existing undesirable surface states as well as protecting the semiconductor device against future impregnation with impurities.

  9. 350 keV accelerator based PGNAA setup to detect nitrogen in bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A., E-mail: aanaqvi@kfupm.edu.sa [Department of Physics and King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Matouq, Faris A.; Khiari, F.Z.; Gondal, M.A.; Rehman, Khateeb-ur [Department of Physics and King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Isab, A.A. [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Raashid, M.; Dastageer, M.A. [Department of Physics and King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2013-11-21

    Nitrogen concentration was measured in explosive and narcotics proxy material, e.g. anthranilic acid, caffeine, melamine, and urea samples, bulk samples through thermal neutron capture reaction using 350 keV accelerator based prompt gamma ray neutron activation (PGNAA) setup. Intensity of 2.52, 3.53–3.68, 4.51, 5.27–5.30 and 10.38 MeV prompt gamma rays of nitrogen from the bulk samples was measured using a cylindrical 100 mm×100 mm (diameter×height ) BGO detector. Inspite of interference of nitrogen gamma rays from bulk samples with capture prompt gamma rays from BGO detector material, an excellent agreement between the experimental and calculated yields of nitrogen gamma rays has been obtained. This is an indication of the excellent performance of the PGNAA setup for detection of nitrogen in bulk samples.

  10. 350 keV accelerator based PGNAA setup to detect nitrogen in bulk samples

    Science.gov (United States)

    Naqvi, A. A.; Al-Matouq, Faris A.; Khiari, F. Z.; Gondal, M. A.; Rehman, Khateeb-ur; Isab, A. A.; Raashid, M.; Dastageer, M. A.

    2013-11-01

    Nitrogen concentration was measured in explosive and narcotics proxy material, e.g. anthranilic acid, caffeine, melamine, and urea samples, bulk samples through thermal neutron capture reaction using 350 keV accelerator based prompt gamma ray neutron activation (PGNAA) setup. Intensity of 2.52, 3.53-3.68, 4.51, 5.27-5.30 and 10.38 MeV prompt gamma rays of nitrogen from the bulk samples was measured using a cylindrical 100 mm×100 mm (diameter×height ) BGO detector. Inspite of interference of nitrogen gamma rays from bulk samples with capture prompt gamma rays from BGO detector material, an excellent agreement between the experimental and calculated yields of nitrogen gamma rays has been obtained. This is an indication of the excellent performance of the PGNAA setup for detection of nitrogen in bulk samples.

  11. Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material

    Science.gov (United States)

    Sopori, Bhushan; Rangappan, Anikara

    2014-11-25

    Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

  12. The Optical Links of the ATLAS SemiConductor Tracker

    CERN Document Server

    Abdesselam, A; Apsimon, R; Band, C; Barr, C; Batchelor, L; Bates, R; Bell, P; Bernabeu, J; Bizzell, J; Brenner, R; Brodbeck, T; Bruckman De Renstrom, P; Buttar, C; Carter, J; Charlton, D; Cheplakov, A; Chilingarov, A; Chu, M-L; Colijn, A-P; Dawson, I; Demirkõz, B; de Jong, P; Dervan, P; Dolezal, Z; Dowell, J; Escobar, P; Spencer, E; Ekelöf, T J C; Eklund, L; Ferrere, D; Fraser, T; French, M; French, R; Fuster, J; Gallop, B; García, C; Goodrick, M; Greenall, A; Grillo, A; Grosse-Knetter, J; Hartjes, F; Hessey, N; Hill, J C; Homer, J; Hou, L; Hughes, G; Ikegami, Y; Issever, C; Jackson, J; Jones, M; Jones, T J; Jovanovic, P; Koffeman, E; Kodys, P; Kohriki, T; Lee, S-C; Lester, C; Limper, M; Lindsay, S W; Lozano, M; Macwaters, C; Magrath, C; Mahout, G; Mandic, I; Matheson, J; McMahon, T; Mikulec, B; Muijs, A; Morrissey, M; Nichols, A; Nickerson, R; O'Shea, V; Pagenis, S; Parker, M; Pater, J; Perrin, E; Pernegger, H; Peeters, S; Phillips, P; Postranecky, M; Robinson, D; Robson, A; Rudge, A; Sandaker, H; Sedlak, K; Smith, N A; Stapnes, S; Stugu, B; Teng, P K; Terada, S; Tricoli, A; Tyndel, M; Ujiie, N; Ullán, M; Unno, Y; van der Kraaij, E; Van Vulpen, I; Viehhauser, G; Vossebeld, J H; Warren, M; Wastie, R; Weidberg, A; Wells, P; White, D; Wilson, J

    2007-01-01

    Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical link requirements are reviewed, with particular emphasis on the very demanding environment at the LHC. The on-detector components have to operate in high radiation levels for 10 years, with no maintenance, and there are very strict requirements on power consumption, material and space. A novel concept for the packaging of the on-detector optoelectronics has been developed to meet these requirements. The system architecture, including its redundancy features, is explained and the critical on-detector components are described. The results of the extensive Quality Assurance performed during all steps of the assembly are discussed. Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical ...

  13. Charge transport optimization in CZT ring-drift detectors

    Science.gov (United States)

    Boothman, V.; Alruhaili, A.; Perumal, V.; Sellin, P.; Lohstroh, A.; Sawhney, K.; Kachanov, S.

    2015-12-01

    Ring-drift design has been applied to large (7.5~\\text{mm}× 7.5~\\text{mm}× 2.3 mm) cadmium zinc telluride (CZT) devices. This low-noise, single-carrier-sensing configuration is the gold standard for spectroscopic silicon x-ray detectors. By combining the advantages of ring-drift with the high quantum efficiency and room-temperature operating capabilities of CZT, a simple and compact device for high-resolution spectroscopy of x-rays in the range 50-500 keV can be created. Quality of CZT crystals has improved greatly in recent years and electron-only sensing overcomes the problem of inherently poor hole transport in II-VI semiconductors. The spatial response of our 3-ring CZT device was studied by microbeam scanning while the voltages applied to all electrodes were systematically varied. Maximum active radius extended to 2.3 mm, beyond the second ring. Resolution was limited by electronic noise. Our results show that the lateral field and its ratio to the bulk field exert a crucial influence on active area, peak position and sensitivity. CZT and the device geometry were modelled in 3D with Sentaurus TCAD. Line scans were simulated and trends in performance with bias conditions matched experimental data, validating the model. We aimed to optimize the resolution, sensitivity and active radius of the device. Fields and charge drift were visualized and the active volume was mapped in 3D to improve understanding of the factors governing performance including number of rings, their widths, positions and bias.

  14. Electroluminescence from indirect band gap semiconductor ReS2

    Science.gov (United States)

    Gutiérrez-Lezama, Ignacio; Aditya Reddy, Bojja; Ubrig, Nicolas; Morpurgo, Alberto F.

    2016-12-01

    It has been recently claimed that bulk crystals of transition metal dichalcogenide (TMD) ReS2 are direct band gap semiconductors, which would make this material an ideal candidate, among all TMDs, for the realization of efficient opto-electronic devices. The situation is however unclear, because even more recently an indirect transition in the PL spectra of this material has been detected, whose energy is smaller than the supposed direct gap. To address this issue we exploit the properties of ionic liquid gated field-effect transistors (FETs) to investigate the gap structure of bulk ReS2. Using these devices, whose high quality is demonstrated by a record high electron FET mobility of 1100 cm2 V-1 s-1 at 4 K, we can induce hole transport at the surface of the material and determine quantitatively the smallest band gap present in the material, irrespective of its direct or indirect nature. The value of the band gap is found to be 1.41 eV, smaller than the 1.5 eV direct optical transition but in good agreement with the energy of the indirect optical transition, providing an independent confirmation that bulk ReS2 is an indirect band gap semiconductor. Nevertheless, contrary to the case of more commonly studied semiconducting TMDs (e.g., MoS2, WS2, etc) in their bulk form, we also find that ReS2 FETs fabricated on bulk crystals do exhibit electroluminescence when driven in the ambipolar injection regime, likely because the difference between direct and indirect gap is only 100 meV. We conclude that ReS2 does deserve more in-depth investigations in relation to possible opto-electronic applications.

  15. Review on nanostructured semiconductors for dye sensitized solar cells

    Science.gov (United States)

    Prakash, T.

    2012-06-01

    Nanostructured semiconductors with different morphologies are used widely in various applications in order to enhance their technological advancements compared with the bulk sample. This flourishing nanoscience field has enabled rapid developments that have created numerous opportunities for scienctific advancements with various devices. Considering large environmental impacts such as global warming, problems of nuclear waste storage and nuclear accidents, there is an urgent need for environmentally sustainable energy technologies such as solar cells and fuel cells. In the present paper, the role of nanostructured semiconductors in dyesensitized solar cells (DSSCs) is reviewed entensively. The review discusses the present developmental prospects of DSSCs and the problems associated with its layer materials and propose a method of overcoming these problems.

  16. Organic / IV, III-V Semiconductor Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Pang-Leen Ong

    2010-03-01

    Full Text Available We present a review of the emerging class of hybrid solar cells based on organic-semiconductor (Group IV, III-V, nanocomposites, which states separately from dye synthesized, polymer-metal oxides and organic-inorganic (Group II-VI nanocomposite photovoltaics. The structure of such hybrid cell comprises of an organic active material (p-type deposited by coating, printing or spraying technique on the surface of bulk or nanostructured semiconductor (n-type forming a heterojunction between the two materials. Organic components include various photosensitive monomers (e.g., phtalocyanines or porphyrines, conjugated polymers, and carbon nanotubes. Mechanisms of the charge separation at the interface and their transport are discussed. Also, perspectives on the future development of such hybrid cells and comparative analysis with other classes of photovoltaics of third generation are presented.

  17. Metal-insulator transition in films of doped semiconductor nanocrystals.

    Science.gov (United States)

    Chen, Ting; Reich, K V; Kramer, Nicolaas J; Fu, Han; Kortshagen, Uwe R; Shklovskii, B I

    2016-03-01

    To fully deploy the potential of semiconductor nanocrystal films as low-cost electronic materials, a better understanding of the amount of dopants required to make their conductivity metallic is needed. In bulk semiconductors, the critical concentration of electrons at the metal-insulator transition is described by the Mott criterion. Here, we theoretically derive the critical concentration nc for films of heavily doped nanocrystals devoid of ligands at their surface and in direct contact with each other. In the accompanying experiments, we investigate the conduction mechanism in films of phosphorus-doped, ligand-free silicon nanocrystals. At the largest electron concentration achieved in our samples, which is half the predicted nc, we find that the localization length of hopping electrons is close to three times the nanocrystals diameter, indicating that the film approaches the metal-insulator transition.

  18. Thin film transistors for flexible electronics: Contacts, dielectrics and semiconductors

    KAUST Repository

    Quevedo-López, Manuel Angel Quevedo

    2011-06-01

    The development of low temperature, thin film transistor processes that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, radiation detectors, etc. In this paper, we review the impact of gate dielectrics, contacts and semiconductor materials on thin film transistors for flexible electronics applications. We present our recent results to fully integrate hybrid complementary metal oxide semiconductors comprising inorganic and organic-based materials. In particular, we demonstrate novel gate dielectric stacks and semiconducting materials. The impact of source and drain contacts on device performance is also discussed. Copyright © 2011 American Scientific Publishers.

  19. Recent progress in picosecond pulse generation from semiconductor lasers

    Science.gov (United States)

    Auyeung, J. C.; Johnston, A. R.

    1982-01-01

    This paper reviews the recent progress in producing picosecond optical pulses from semiconductor laser diodes. The discussion concentrates on the mode-locking of a semiconductor laser diode in an external resonator. Transform-limited optical pulses ranging from several picoseconds to subpicosecond durations have been observed with active and passive mode-locking. Even though continuing research on the influence of impurities and defects on the mode-locking process is still needed, this technique has good promise for being utilized in fiber-optic communication systems. Alternative methods of direct electrical and optical excitation to produce ultrashort laser pulses are also described. They can generate pulses of similar widths to those obtained by mode-locking. The pulses generated will find applications in laser ranging and detector response measurement.

  20. Thin film transistors for flexible electronics: contacts, dielectrics and semiconductors.

    Science.gov (United States)

    Quevedo-Lopez, M A; Wondmagegn, W T; Alshareef, H N; Ramirez-Bon, R; Gnade, B E

    2011-06-01

    The development of low temperature, thin film transistor processes that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, radiation detectors, etc. In this paper, we review the impact of gate dielectrics, contacts and semiconductor materials on thin film transistors for flexible electronics applications. We present our recent results to fully integrate hybrid complementary metal oxide semiconductors comprising inorganic and organic-based materials. In particular, we demonstrate novel gate dielectric stacks and semiconducting materials. The impact of source and drain contacts on device performance is also discussed.

  1. Picosecond response of a photon drag detector

    Energy Technology Data Exchange (ETDEWEB)

    Kimmitt, M.F. [Univ. of Essex (United Kingdom)

    1995-12-31

    The primary use of photon drag detectors has been with CO{sub 2} lasers at 10{mu}m. Cornmercially-available devices are limited to response times of < 0.5-1ns and voltage responsivities of <0.5{mu}V W{sup -1}. This poster paper will describe the first photon drag detector specifically designed for very fast response. Using the free-election laser FELIX at the FOM Institute in the Netherlands, a rise time of <50ps has been demonstrated, using a 5mm{sup 2} area detector with a responsivity of >1{mu}V W{sup -1} over the wavelength range 10-25{mu}m. The figure shows the clear resolution of the micropulse structure of the laser. The actual width of each pulse is a few picosecoods, with a micropulse spacing of Ins. The advantages or photon drag detectors are room-temperature operation, linear response to intensifies greater than 10{sup 6}MW cm{sup -2} and very high damage threshold. These detectors are cheap to manufacture and, using different semiconductors, can be designed for any wavelength from 1 {mu}m-5mm.

  2. SPECT detectors: the Anger Camera and beyond

    Science.gov (United States)

    Peterson, Todd E.; Furenlid, Lars R.

    2011-09-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous sodium iodide scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic.

  3. Review of surface photovoltage spectra of nano-sized semiconductor and its applications in heterogeneous photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Liqiang, Jing; Honggang, Fu [School of Chemistry and Chemical Technology, Heilongjiang University, Harbin 150001 (China); Xiaojun, Sun; Weimin, Cai [Department of Environmental Sciences and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Jing, Shang; Zili, Xu; Yaoguo, Du [Department of Environmental Sciences and Engineering, Jilin University, Changchun 150001 (China)

    2003-09-01

    Heterogeneous photocatalysis is a promising technique valuable for environmental purification. Nano-sized semiconductors such as ZnO and TiO{sub 2}, which is one of the most basic functional materials, have emerged as effective photocatalyst materials. The surface photovoltage spectra (SPS) can be an effective method for quickly evaluating the photocatalytic activity of semiconductor materials since it can provide a rapid, non-destructive monitor of the semiconductor surface properties such as surface band bending, surface and bulk carrier recombination and surface states, mainly showing the carrier separation and transfer behavior with the aid of light, especially the electric-field-induced surface photovoltage spectra (EFISPS), in which SPS is combined with the electric-field-modified technique. In this review, the basic principles, measurement and applications of the SPS and EFISPS are mainly discussed together with some fundamental aspects like the electric properties of semiconductor surface and the principle of electric field effect. In particular, the applications of SPS to nano-sized semiconductors such as ZnO and TiO{sub 2} in heterogeneous photocatalysis are emphasized, which involve mainly evaluating the photocatalytic activity by analyzing semiconductor surface properties such as the separation efficiency of photoinduced carriers under illumination by the SPS measurement, highlighting our own contributions. The results show that the weaker the surface photovoltage signal is, the higher the photocatalytic activity is in the case of nano-sized semiconductor photocatalysts.

  4. Review of surface photovoltage spectra of nano-sized semiconductor and its applications in heterogeneous photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Jing Liqiang [Heilongjiang Univ., School of Chemistry and Chemical Technology, Harbin (China); Harbin Inst. of Technology, Dept. of Environmental Sciences and Engineering, Harbin (China); Sun Xiaojun; Cai Weimin [Harbin Inst. of Technology, Dept. of Environmental Sciences and Engineering, Harbin (China); Shang Jing; Xu Zili; Du Yaoguo [Jilin Univ., Dept. of Environmental Sciences and Engineering, Changchun (China); Fu Honggang [Heilongjiang Univ., School of Chemistry and Chemical Technology, Harbin (China)

    2003-09-01

    Heterogeneous photocatalysis is a promising technique valuable for environmental purification. Nano-sized semiconductors such as ZnO and TiO{sub 2}, which is one of the most basic functional materials, have emerged as effective photocatalyst materials. The surface photovoltage spectra (SPS) can be an effective method for quickly evaluating the photocatalytic activity of semiconductor materials since it can provide a rapid, non-destructive monitor of the semiconductor surface properties such as surface band bending, surface and bulk carrier recombination and surface states, mainly showing the carrier separation and transfer behavior with the aid of light, especially the electric-field-induced surface photovoltage spectra (EFISPS), in which SPS is combined with the electric-field-modified technique. In this review, the basic principles, measurement and applications of the SPS and EFISPS are mainly discussed together with some fundamental aspects like the electric properties of semiconductor surface and the principle of electric field effect. In particular, the applications of SPS to nano-sized semiconductors such as ZnO and TiO{sub 2} in heterogeneous photocatalysis are emphasized, which involve mainly evaluating the photocatalytic activity by analyzing semiconductor surface properties such as the separation efficiency of photoinduced carriers under illumination by the SPS measurement, highlighting our own contributions. The results show that the weaker the surface photovoltage signal is, the higher the photocatalytic activity is in the case of nano-sized semiconductor photocatalysts. (Author)

  5. Quantum optics with semiconductor nanostructures

    CERN Document Server

    Jahnke, Frank

    2012-01-01

    A guide to the theory, application and potential of semiconductor nanostructures in the exploration of quantum optics. It offers an overview of resonance fluorescence emission.$bAn understanding of the interaction between light and matter on a quantum level is of fundamental interest and has many applications in optical technologies. The quantum nature of the interaction has recently attracted great attention for applications of semiconductor nanostructures in quantum information processing. Quantum optics with semiconductor nanostructures is a key guide to the theory, experimental realisation, and future potential of semiconductor nanostructures in the exploration of quantum optics. Part one provides a comprehensive overview of single quantum dot systems, beginning with a look at resonance fluorescence emission. Quantum optics with single quantum dots in photonic crystal and micro cavities are explored in detail, before part two goes on to review nanolasers with quantum dot emitters. Light-matter interaction...

  6. Semiconductor nanoparticles for quantum devices

    Science.gov (United States)

    Erokhin, Victor; Carrara, Sandro; Amenitch, H.; Bernstorff, S.; Nicolini, Claudio

    1998-09-01

    Semiconductor nanoparticles were synthesized by exposing fatty acid salt Langmuir-Blodgett films to the atmosphere of 0957-4484/9/3/004/img8. The particle sizes were characterized by small-angle x-ray scattering of their solutions using synchrotron radiation source at higher resolution, as it was impossible previously to study it with usual laboratory x-ray sources. The particle sizes were found to correspond with the demands of single-electron and quantum junctions. Semiconductor heterostructures were grown by self-aggregation of these particles of different types. Electrical properties of these nanostructures were studied by using STM. Voltage-current characteristics revealed the presence of differential negative resistance. Measurements confirmed the formation of semiconductor superlattices directed towards a development of new nanodevices, such as tunnelling diodes and semiconductor lasers.

  7. Metal-Insulator-Semiconductor Photodetectors

    Directory of Open Access Journals (Sweden)

    Chu-Hsuan Lin

    2010-09-01

    Full Text Available The major radiation of the Sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  8. Thermal neutron detectors based on hexagonal boron nitride epilayers

    Science.gov (United States)

    Doan, T. C.; Marty, A.; Li, J.; Lin, J. Y.; Jiang, H. X.

    2016-09-01

    Solid-state neutron detectors with high performances are urgently sought after for the detection of fissile materials. Until now, direct-conversion neutron detectors based on semiconductors with a measureable efficiency have not been realized. We have successfully synthesized hexagonal boron nitride (h-BN) epilayers with varying thicknesses (0.3 μm - 50 μm) by metal organic chemical vapor deposition (MOCVD) on sapphire substrates. In this paper, we present the detailed characterization of thermal neutron detectors fabricated from h-BN epilayers with a thickness up to 5 m to obtain insights into the h-BN epilayer thickness dependence of the device performance. The results revealed that the charge collection efficiency is almost independent of the h-BN epilayer thickness. By minimizing h-BN material removal by dry etching, it was shown that detectors incorporating an isotopically 10B-enriched h-BN epilayer of 2.7 μm in thickness exhibited an overall detection efficiency for thermal neutrons of 4% and a charge collection efficiency as high as 83%. By doing away altogether with dry etching, we have successfully realized a simple vertical 43 μm thick h-10BN detector which delivers a detection efficiency of 51.4% for thermal neutrons, which is the highest reported efficiency for any semiconductor-based neutron detector The h-BN detectors possess all the advantages of semiconductor devices including low cost, high efficiency and sensitivity, wafer-scale processing, compact size, light weight, and ability to integrate with other functional devices.

  9. Heterojunction and superlattice detectors for infrared to ultraviolet

    Science.gov (United States)

    Perera, A. G. U.

    2016-07-01

    The interest in Infrared and Ultraviolet detectors has increased immensely due to the emergence of important applications over a wide range of activities. Detectors based on free carrier absorption known as Hetero-junction Interfacial Workfunction Internal Photoemission (HEIWIP) detectors and variations of these heterojunction structures to be used as intervalence band detectors for a wide wavelength region are presented. Although this internal photoemission concept is valid for all semiconductor materials systems, using a well-studied III-V system of GaAs/AlxGa1-x As to cover a wide wavelength range from UV to far-infrared (THz) is an important development in detector technology. Using the intervalence band (heavy hole, light hole and split off) transitions for high operating temperature detection of mid Infrared radiation is also discussed. A promising new way to extend the detection wavelength threshold beyond the standard threshold connected with the energy gap in a GaAs/AlxGa1-x As system is also presented. Superlattice detector technology, which is another promising detector architecture, can be optimized using both Type I and Type II heterostructures. Here the focus will be on Type II Strained Layer (T2SL) Superlattice detectors. T2SL Superlattices based on InAs/(In,GA)Sb have made significant improvements demonstrating focal plane arrays operating around 80 K and with multiple band detection capability. A novel spectroscopic method to evaluate the band offsets of both heterojunction and superlattice detectors is also discussed.

  10. Semiconductor packaging materials interaction and reliability

    CERN Document Server

    Chen, Andrea

    2012-01-01

    In semiconductor manufacturing, understanding how various materials behave and interact is critical to making a reliable and robust semiconductor package. Semiconductor Packaging: Materials Interaction and Reliability provides a fundamental understanding of the underlying physical properties of the materials used in a semiconductor package. The book focuses on an important step in semiconductor manufacturing--package assembly and testing. It covers the basics of material properties and explains how to determine which behaviors are important to package performance. The authors also discuss how

  11. Optical Orientation in Ferromagnet/Semiconductor Hybrids

    OpenAIRE

    Korenev, V. L.

    2008-01-01

    The physics of optical pumping of semiconductor electrons in the ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of the ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of the semiconductor. Spin-spin interactions near the interface ferromagnet/semiconductor play crucial role in the optical readout and the manipulation of ferromagnetism.

  12. Fractal properties of nanostructured semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Zhanabaev, Z.Zh. [Al-Farabi Khazakh National University, Tole bi Street, 96, Almaty 050012 (Kazakhstan); Grevtseva, T.Yu. [Al-Farabi Khazakh National University, Tole bi Street, 96, Almaty 050012 (Kazakhstan)]. E-mail: kenwp@mail.ru

    2007-03-15

    A theory for the temperature and time dependence of current carrier concentration in semiconductors with different non-equilibrium nanocluster structure has been developed. It was shown that the scale-invariant fractal self-similar and self-affine laws can exist near by the transition point to the equilibrium state. Results of the theory have been compared to the experimental data from electrical properties of semiconductor films with nanoclusters.

  13. Seebeck effect in polycrystalline semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Jerhot, J.; Vlcek, J.

    1982-06-18

    The paper deals with the interpretation of the Seebeck coefficient measured for a polycrystalline semiconductor. Polycrystalline semiconductors are considered to be composed of grains separated from one another by intergrain domains. An isotype heterojunction with a certain density of interface states is assumed to exist at the grain-intergrain domain interface. The general formula for the Seebeck coefficient under these conditions is derived. The relations valid for systems of practical interest are shown as limiting cases of the formula presented.

  14. A semiconductor laser excitation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Kaadzunari, O.; Masaty, K.

    1984-03-27

    A semiconductor laser excitation circuit is patented that is designed for operation in a pulsed mode with a high pulse repetition frequency. This circuit includes, in addition to a semiconductor laser, a high speed photodetector, a reference voltage source, a comparator, and a pulse oscillator and modulator. If the circuit is built using standard silicon integrated circuits, its speed amounts to several hundred megahertz, if it is constructed using gallium arsenide integrated circuits, its speed is several gigahertz.

  15. Semiconductors for plasmonics and metamaterials

    DEFF Research Database (Denmark)

    Naik, G.V.; Boltasseva, Alexandra

    2010-01-01

    Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals with semiconduct......Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals...... with semiconductors can alleviate these problems if only semiconductors could exhibit negative real permittivity. Aluminum doped zinc oxide (AZO) is a low loss semiconductor that can show negative real permittivity in the NIR. A comparative assessment of AZO-based plasmonic devices such as superlens and hyperlens...... with their metal-based counterparts shows that AZO-based devices significantly outperform at a wavelength of 1.55 µm. This provides a strong stimulus in turning to semiconductor plasmonics at the telecommunication wavelengths. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)....

  16. Survey of cryogenic semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Talarico, L.J.; McKeever, J.W.

    1996-04-01

    Improved reliability and electronic performance can be achieved in a system operated at cryogenic temperatures because of the reduction in mechanical insult and in disruptive effects of thermal energy on electronic devices. Continuing discoveries of new superconductors with ever increasing values of T{sub c} above that of liquid nitrogen temperature (LNT) have provided incentive for developing semiconductor electronic systems that may also operate in the superconductor`s liquid nitrogen bath. Because of the interest in high-temperature superconductor (HTS) devices, liquid nitrogen is the cryogen of choice and LNT is the temperature on which this review is focused. The purpose of this survey is to locate and assemble published information comparing the room temperature (298 K), performance of commercially available conventional and hybrid semiconductor device with their performance at LNT (77K), to help establish their candidacy as cryogenic electronic devices specifically for use at LNT. The approach to gathering information for this survey included the following activities. Periodicals and proceedings were searched for information on the behavior of semiconductor devices at LNT. Telephone calls were made to representatives of semiconductor industries, to semiconductor subcontractors, to university faculty members prominent for their research in the area of cryogenic semiconductors, and to representatives of the National Aeronautics and Space Administration (NASA) and NASA subcontractors. The sources and contacts are listed with their responses in the introduction, and a list of references appears at the end of the survey.

  17. A semiconductor laser

    Energy Technology Data Exchange (ETDEWEB)

    Naoko, O.; Khiroiti, S.

    1984-05-20

    An improved method is patented for increasing the service life of semiconductor lasers which does not hinder their characteristics, by applying a protective film to the end planes of the optical resonator of the laser. It is recommended that a mixture of an A1203 dielectric and an inert element such as argon be used for a GaAs, GaA1As laser as the protective film. The radii of gallium and arsenic atoms are equal to 1.24 and 1.25 angstroms, respectively. The radii of A1, O and Si atoms which make up the protective film are equal to 1.43, .61 and 1.17 angstroms, respectively. The radius of the argon atoms in the protective film, which is equal to 1.91 angstroms) is high compared to the atoms noted above. As a result, the movement of the gallium and arsenic atoms, which causes a drop in later characteristics during operation, is made more difficult.

  18. Crossing and anti-crossing effects of polaritons in a magnetic-semiconductor superlattice influenced by an external magnetic field

    Science.gov (United States)

    Tuz, Vladimir R.; Fesenko, Volodymyr I.; Fedorin, Illia V.; Sun, Hong-Bo; Shulga, Valeriy M.

    2017-03-01

    Crossing and anti-crossing effects in dispersion characteristics of both bulk and surface polaritons in a magnetic-semiconductor superlattice influenced by an external static magnetic field being in the Faraday geometry are discussed. The bulk polaritons are classified as eigenwaves with right-handed and left-handed elliptically polarized states, whereas the surface polaritons are considered as hybrid modes having a predominant effect of either magnetic or semiconductor subsystem, and distinctions in dispersion characteristics of such polaritons are revealed involving the concept of critical points.

  19. Looking for a bulk point

    CERN Document Server

    Maldacena, Juan; Zhiboedov, Alexander

    2015-01-01

    We consider Lorentzian correlators of local operators. In perturbation theory, singularities occur when we can draw a position-space Landau diagram with null lines. In theories with gravity duals, we can also draw Landau diagrams in the bulk. We argue that certain singularities can arise only from bulk diagrams, not from boundary diagrams. As has been previously observed, these singularities are a clear diagnostic of bulk locality. We analyze some properties of these perturbative singularities and discuss their relation to the OPE and the dimensions of double-trace operators. In the exact nonperturbative theory, we expect no singularity at these locations. We prove this statement in 1+1 dimensions by CFT methods.

  20. EDITORIAL: Oxide semiconductors

    Science.gov (United States)

    Kawasaki, M.; Makino, T.

    2005-04-01

    Blue or ultraviolet semiconducting light-emitting diodes have the potential to revolutionize illumination systems in the near-future. Such industrial need has propelled the investigation of several wide-gap semiconducting materials in recent years. Commercial applications include blue lasers for DVD memory and laser printers, while military applications are also expected. Most of the material development has so far been focused on GaN (band gap 3.5 eV at 2 K), and ZnSe (2.9 eV) because these two representative direct transition semiconductors are known to be bright emitting sources. GaN and GaN-based alloys are emerging as the winners in this field because ZnSe is subject to defect formation under high current drive. On the other hand, another II-VI compound, ZnO, has also excited substantial interest in the optoelectronics-oriented research communities because it is the brightest emitter of all, owing to the fact that its excitons have a 60 meV binding energy. This is compared with 26 meV for GaN and 20 meV for ZnSe. The stable excitons could lead to laser action based on their recombination even at temperatures well above room temperature. ZnO has additional major properties that are more advantageous than other wide-gap materials: availability of large area substrates, higher energy radiation stability, environmentally-friendly ingredients, and amenability to wet chemical etching. However, ZnO is not new to the semiconductor field as exemplified by several studies made during the 1960s on structural, vibrational, optical and electrical properties (Mollwo E 1982 Landolt-Boernstein New Series vol 17 (Berlin: Springer) p 35). In terms of devices, the luminescence from light-emitting diode structures was demonstrated in which Cu2O was used as the p-type material (Drapak I T 1968 Semiconductors 2 624). The main obstacle to the development of ZnO has been the lack of reproducible p-type ZnO. The possibility of achieving epitaxial p-type layers with the aid of thermal

  1. 75 FR 49526 - Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor...

    Science.gov (United States)

    2010-08-13

    ... Employment and Training Administration Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor, Inc., Technical Information Center, Woburn, MA; Amended Certification Regarding... Semiconductor, Inc., Technical Information Center, Tempe, Arizona. The notice was published in the...

  2. Semiconductor Laser Theory: The Maxwell--Bloch Equations

    Science.gov (United States)

    Gehrig, Edeltraud; Hess, Ortwin

    Because of its central importance for fundamental physics as well as for technological applications, the electronic structure of layered semiconductor structures has attracted much interest over the last two decades. In theoretical studies, methods based on the envelope function approximation are predominant, the reason being that the EFA allows a comprehensive description of electron- and hole-like states. It can cope with periodic or aperiodic geometries of quantum structures, as well as perturbations such as a magnetic field, strain, or a built-in or external potential. Details of the underlying crystal potential are included in terms of bulk band structure parameters.

  3. Theory of the Fermi-level energy in semiconductor superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Luscombe, J.H. (Central Research Laboratories, Texas Instruments Incorporated, Dallas, Texas (USA)); Aggarwal, R. (Central Research Laboratories, Texas Instruments Incorporated, Dallas, Texas (USA) Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts (USA)); Reed, M.A. (Central Research Laboratories, Texas Instruments Incorporated, Dallas, Texas (USA) Department of Electrical Engineering, Yale University, New Haven, Connecticut (USA)); Frensley, W.R. (Central Research Laboratories, Texas Instruments Incorporated, Dallas, Texas (USA) Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas (USA)); Luban, M. (Iowa Univ., Iowa City, IA (USA). Dept. of Physics and Astronomy Ames Lab., IA (USA))

    1991-09-15

    A theoretical study of the properties of the Fermi level in semiconductor superlattices (SL's) is made which is based upon the carrier occupation of the minibands in thermal equilibrium. We find, for a fixed carrier density and temperature, that the SL Fermi level can differ significantly from that obtained using commonly employed three-dimensional approximations, depending upon the relative spacings and widths of the minibands, with the SL Fermi level being higher than the corresponding bulk value. We find that the SL Fermi level is a sensitive function of the relative widths of the quantum wells and barriers.

  4. A semiconductor laser for an integrated optical heterodyne receiver

    Energy Technology Data Exchange (ETDEWEB)

    Tosikhiro, F.; Khiromoto, S.

    1984-04-14

    A design is patented that consists of two identical semiconductor lasers grown on the same substrate, one of which is used to transmit the information signal and the other is used as the oscillator. The oscillator frequency is tuned by varying the laser resonator length. The signals from the two oscillators are mixed at the transmitting end of the communications link, which makes it possible to reduce losses during the introduction of the signal to the fiber and the detector. This design serves to reduce the influence of temperature variations.

  5. Bulk nano-crystalline alloys

    OpenAIRE

    T.-S. Chin; Lin, C. Y.; Lee, M.C.; R.T. Huang; S. M. Huang

    2009-01-01

    Bulk metallic glasses (BMGs) Fe–B–Y–Nb–Cu, 2 mm in diameter, were successfully annealed to become bulk nano-crystalline alloys (BNCAs) with α-Fe crystallite 11–13 nm in size. A ‘crystallization-and-stop’ model was proposed to explain this behavior. Following this model, alloy-design criteria were elucidated and confirmed successful on another Fe-based BMG Fe–B–Si–Nb–Cu, 1 mm in diameter, with crystallite sizes 10–40 nm. It was concluded that BNCAs can be designed in general by the proposed cr...

  6. Recent Progress on 3D Silicon Detectors

    CERN Document Server

    Lange, Jörn

    2015-01-01

    3D silicon detectors, in which the electrodes penetrate the sensor bulk perpendicular to the surface, have recently undergone a rapid development from R\\&D over industrialisation to their first installation in a real high-energy-physics experiment. Since June 2015, the ATLAS Insertable B-Layer is taking first collision data with 3D pixel detectors. At the same time, preparations are advancing to install 3D pixel detectors in forward trackers such as the ATLAS Forward Proton detector or the CMS-TOTEM Proton Precision Spectrometer. For those experiments, the main requirements are a slim edge and the ability to cope with non-uniform irradiation. Both have been shown to be fulfilled by 3D pixel detectors. For the High-Luminosity LHC pixel upgrades of the major experiments, 3D detectors are promising candidates for the innermost pixel layers to cope with harsh radiation environments up to fluences of $2\\times10^{16}$\\,n$_{eq}$/cm$^2$ thanks to their excellent radiation hardness at low operational voltages and ...

  7. GADRAS Detector Response Function.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  8. The TALE Tower Detector

    Science.gov (United States)

    Bergman, D. R.

    The TA Low Energy Extension will include a Tower FluorescenceDetector. Extensive air showers at the lowest usful energies for fluorescence detectors will in general be close to the detector. This requires viewing all elevation angles to be able to reconstruct showers. The TALE Tower Detector, operating in conjunction with other TALE detectors will view elevation angles up to above 70 degrees, with an azimuthal coverage of about 90 degrees. Results from a prototype mirror operated in conjunction with the HiRes detector will also be presented.

  9. High resolution imaging detectors and applications

    CERN Document Server

    Saha, Swapan K

    2015-01-01

    Interferometric observations need snapshots of very high time resolution of the order of (i) frame integration of about 100 Hz or (ii) photon-recording rates of several megahertz (MHz). Detectors play a key role in astronomical observations, and since the explanation of the photoelectric effect by Albert Einstein, the technology has evolved rather fast. The present-day technology has made it possible to develop large-format complementary metal oxide–semiconductor (CMOS) and charge-coupled device (CCD) array mosaics, orthogonal transfer CCDs, electron-multiplication CCDs, electron-avalanche photodiode arrays, and quantum-well infrared (IR) photon detectors. The requirements to develop artifact-free photon shot noise-limited images are higher sensitivity and quantum efficiency, reduced noise that includes dark current, read-out and amplifier noise, smaller point-spread functions, and higher spectral bandwidth. This book aims to address such systems, technologies and design, evaluation and calibration, control...

  10. Advanced digital detectors for neutron imaging.

    Energy Technology Data Exchange (ETDEWEB)

    Doty, F. Patrick

    2003-12-01

    Neutron interrogation provides unique information valuable for Nonproliferation & Materials Control and other important applications including medicine, airport security, protein crystallography, and corrosion detection. Neutrons probe deep inside massive objects to detect small defects and chemical composition, even through high atomic number materials such as lead. However, current detectors are bulky gas-filled tubes or scintillator/PM tubes, which severely limit many applications. Therefore this project was undertaken to develop new semiconductor radiation detection materials to develop the first direct digital imaging detectors for neutrons. The approach relied on new discovery and characterization of new solid-state sensor materials which convert neutrons directly to electronic signals via reactions BlO(n,a)Li7 and Li6(n,a)T.

  11. Signal processors for position-sensitive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Ken-ichi [Hosei Univ., Koganei, Tokyo (Japan). Coll. of Engineering

    1996-07-01

    Position-sensitive detectors (PSD) are widely used in following various fields: condensed matter studies, material engineering, medical radiology particle physics, astrophysics and industrial applications. X-ray diffraction analysis is one of the field where PSDs are the most important instruments. In this field, many types of PSAs are employed: position-sensitive proportional counters (PSPC), multi-wire proportional chambers (MWPC), imaging plates, image intensifiers combined CCD cameras and semiconductor array devices. Two readout systems used for PSDs, where one is a charge-division type with high stability and the other is an encoder with multiple delay, line readout circuits useful for fast counting, were reported in this paper. The multiple delay line encoding system can be applicable to high counting rate 1D and 2D gas proportional detectors. (G.K.)

  12. Non-gated laser-induced breakdown spectroscopy in bulk water by position-selective detection

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Ye; Xue, Boyang; Song, Jiaojian; Lu, Yuan; Zheng, Ronger, E-mail: rzheng@ouc.edu.cn [Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao 266100 (China)

    2015-09-14

    Temporal and spatial evolutions of the laser-induced plasma in bulk water are investigated using fast imaging and emission spectroscopic techniques. By tightly focusing a single-pulse nanosecond Nd: YAG laser beam into the bulk water, we generate a strongly expanded plasma with high reproducibility. Such a strong expanding plasma enables us to obtain well-resolved spectral lines by means of position-selective detection; hence, the time-gated detector becomes abdicable. The present results suggest not only a possible non-gated approach for underwater laser-induced breakdown spectroscopy but also give an insight into the plasma generation and expansion in bulk water.

  13. Wide-Bandgap Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chinthavali, M.S.

    2005-11-22

    With the increase in demand for more efficient, higher-power, and higher-temperature operation of power converters, design engineers face the challenge of increasing the efficiency and power density of converters [1, 2]. Development in power semiconductors is vital for achieving the design goals set by the industry. Silicon (Si) power devices have reached their theoretical limits in terms of higher-temperature and higher-power operation by virtue of the physical properties of the material. To overcome these limitations, research has focused on wide-bandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond because of their superior material advantages such as large bandgap, high thermal conductivity, and high critical breakdown field strength. Diamond is the ultimate material for power devices because of its greater than tenfold improvement in electrical properties compared with silicon; however, it is more suited for higher-voltage (grid level) higher-power applications based on the intrinsic properties of the material [3]. GaN and SiC power devices have similar performance improvements over Si power devices. GaN performs only slightly better than SiC. Both SiC and GaN have processing issues that need to be resolved before they can seriously challenge Si power devices; however, SiC is at a more technically advanced stage than GaN. SiC is considered to be the best transition material for future power devices before high-power diamond device technology matures. Since SiC power devices have lower losses than Si devices, SiC-based power converters are more efficient. With the high-temperature operation capability of SiC, thermal management requirements are reduced; therefore, a smaller heat sink would be sufficient. In addition, since SiC power devices can be switched at higher frequencies, smaller passive components are required in power converters. Smaller heat sinks and passive components result in higher-power-density power converters

  14. Dielectric screening in semiconductors

    Science.gov (United States)

    Harrison, Walter A.; Klepeis, John E.

    1988-01-01

    Intra-atomic and interatomic Coulomb interactions are incorporated into bond-orbital theory, based upon universal tight-binding parameters, in order to treat the effects of charge redistribution in semiconductor bonds. The dielectric function ɛ(q) is obtained for wave numbers in a [100] direction. The screening of differences in average hybrid energy across a heterojunction is calculated in detail, indicating that the decay length for the potential depends upon the relative values of Madelung and intra-atomic Coulomb terms. The parameters used here predict an imaginary decay length and thus an oscillating potential near the interface. The same theory is applied to point defects by imbedding a cluster in a matrix lattice, taking charges in that lattice to be consistent with continuum theory. Illustrating the theory with a phosphorus impurity in silicon, it is seen that the impurity and its neighboring atoms have charges on the order of only one-tenth of an electronic charge, alternating in sign from neighbor to neighbor as for planar defects. Although there are shifts in the term values on the order of a volt, the difference in these shifts for neighboring atoms is much smaller so that the effect on the bonds is quite small. This behavior is analogous to the response of a dielectric continuum to a point charge: The medium is locally neutral except at the center of the cluster and there are slowly varying potentials e2/ɛr. Because of this slow variation, free-atom term values should ordinarily suffice for the calculation of bond properties and bond lengths at impurities. Corrections are larger for homovalent substitutions such as carbon in silicon.

  15. Theoretical study of time-resolved luminescence in semiconductors. I. Decay from the steady state

    Energy Technology Data Exchange (ETDEWEB)

    Maiberg, Matthias, E-mail: matthias.maiberg@physik.uni-halle.de; Scheer, Roland [Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06120 Halle (Germany)

    2014-09-28

    Time-resolved luminescence (TRL) is a non-destructive, non-invasive, and contactless characterization method. We studied TRL decay on semiconductor layers and thin film homostructures after a steady state illumination by simulation with Synopsys TCAD{sup ®} and by analytical approximate solution of the appropriate equations. First, we show that the luminescence decay time in general equals the minority carrier lifetime only for a homogeneous and time-independent carrier lifetime. Then, we investigate the influence of photon recycling, injection level, charge carrier diffusion, defects in the bulk and at the surfaces, as well as space charge on the TRL decay separately by quasi one-dimensional simulations of semiconductor layers and semiconductor homostructures. We further study the influence of sample non-homogeneity as may be found in polycrystalline semiconductors. We show how carrier lifetime can be extracted from the TRL transients and how the samples can be characterized by excitation dependent measurements in the open circuit case. We can explain some effects found in luminescence experiments, like a decrease of the decay time with an increasing excitation, a maximum in the decay time due to saturated bulk-defects and curved luminescence transients due to high injections or sample inhomogeneities. Furthermore, we are focussing on the question, how single layers within a semiconductor stack can be characterized.

  16. Details in Semiconductors Gordon Conference, New London, NH, August 3-8, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Shengbai Zhang and Nancy Ryan Gray

    2009-09-16

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in homogeneous and structured semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, with an increases emphasis on nanostructures as compared to previous conferences. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference deals with defects in a broad range of bulk and nanoscale electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, doped nanoparticles, and organic semiconductors. Presentations of state-of-the-art theoretical methods will contribute to a fundamental understanding of atomic-scale phenomena. The program consists of about twenty invited talks, with plenty of discussion time, and a number of contributed poster sessions. Because of the large amount of discussion time, the conference provides an ideal forum for dealing with topics that are new and/or controversial.

  17. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Martinez laso, L.

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  18. Steady-state photoluminescent excitation characterization of semiconductor carrier recombination

    Energy Technology Data Exchange (ETDEWEB)

    Bhosale, J. S. [Intel Corporation, Hillsboro, Oregon 97124 (United States); Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Moore, J. E.; Wang, X.; Bermel, P.; Lundstrom, M. S. [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2016-01-15

    Photoluminescence excitation spectroscopy is a contactless characterization technique that can provide valuable information about the surface and bulk recombination parameters of a semiconductor device, distinct from other sorts of photoluminescent measurements. For this technique, a temperature-tuned light emitting diode (LED) has several advantages over other light sources. The large radiation density offered by LEDs from near-infrared to ultraviolet region at a low cost enables efficient and fast photoluminescence measurements. A simple and inexpensive LED-based setup facilitates measurement of surface recombination velocity and bulk Shockley-Read-Hall lifetime, which are key parameters to assess device performance. Under the right conditions, this technique can also provide a contactless way to measure the external quantum efficiency of a solar cell.

  19. Corrosion processes in quantized semiconductor colloids studied by pulse radiolysis

    Energy Technology Data Exchange (ETDEWEB)

    Nenadovic, M.T.; Nedeljkovic, J.M.; Micic, O.I.

    1987-04-01

    Electron-transfer reactions from different electron donors to PbSe colloids with diameter size less than 5 nm were studied by pulse-radiolysis techniques. Colloidal particles accept electrons from redox couples whose redox potentials are more negative than -0.8 V (vs. NHE). The optical properties of injected electrons show formation of Pb/sup +/ in bulk semiconductor after 1 ms and then reduction to Pb/sup 0/ in a second slower step ca. 10 s after electron injection. This cathodic corrosion process is also the dominant process during illumination of the colloids in the presence of hole scavengers. The photoreductive corrosion can be partially suppressed in the presence of an electron acceptor. Reduction reactions that cannot occur in bulk materials can occur in sufficiently small particles. Other quantized metal selenides show similar behaviour. The largest yield of hydrogen was produced with extremely small ZnSe colloids.

  20. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja

    2009-01-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise i...