WorldWideScience

Sample records for nonvolatile hot-electron injection

  1. Electrogenerated chemiluminescence induced by sequential hot electron and hole injection into aqueous electrolyte solution

    Energy Technology Data Exchange (ETDEWEB)

    Salminen, Kalle; Kuosmanen, Päivi; Pusa, Matti [Aalto University, Department of Chemistry, Laboratory of Analytical Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Kulmala, Oskari [University of Helsinki, Department of Physics, P.O. Box 64, FI-00014 (Finland); Håkansson, Markus [Aalto University, Department of Chemistry, Laboratory of Analytical Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Kulmala, Sakari, E-mail: sakari.kulmala@aalto.fi [Aalto University, Department of Chemistry, Laboratory of Analytical Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland)

    2016-03-17

    Hole injection into aqueous electrolyte solution is proposed to occur when oxide-coated aluminum electrode is anodically pulse-polarized by a voltage pulse train containing sufficiently high-voltage anodic pulses. The effects of anodic pulses are studied by using an aromatic Tb(III) chelate as a probe known to produce intensive hot electron-induced electrochemiluminescence (HECL) with plain cathodic pulses and preoxidized electrodes. The presently studied system allows injection of hot electrons and holes successively into aqueous electrolyte solutions and can be utilized in detecting electrochemiluminescent labels in fully aqueous solutions, and actually, the system is suggested to be quite close to a pulse radiolysis system providing hydrated electrons and hydroxyl radicals as the primary radicals in aqueous solution without the problems and hazards of ionizing radiation. The analytical power of the present excitation waveforms are that they allow detection of electrochemiluminescent labels at very low detection limits in bioaffinity assays such as in immunoassays or DNA probe assays. The two important properties of the present waveforms are: (i) they provide in situ oxidation of the electrode surface resulting in the desired oxide film thickness and (ii) they can provide one-electron oxidants for the system by hole injection either via F- and F{sup +}-center band of the oxide or by direct hole injection to valence band of water at highly anodic pulse amplitudes. - Highlights: • Hot electrons injected into aqueous electrolyte solution. • Generation of hydrated electrons. • Hole injection into aqueous electrolyte solution. • Generation of hydroxyl radicals.

  2. Hot-electron effect in spin relaxation of electrically injected electrons in intrinsic Germanium.

    Science.gov (United States)

    Yu, T; Wu, M W

    2015-07-01

    The hot-electron effect in the spin relaxation of electrically injected electrons in intrinsic germanium is investigated by the kinetic spin Bloch equations both analytically and numerically. It is shown that in the weak-electric-field regime with E ≲ 0.5 kV cm(-1), our calculations have reasonable agreement with the recent transport experiment in the hot-electron spin-injection configuration (2013 Phys. Rev. Lett. 111 257204). We reveal that the spin relaxation is significantly enhanced at low temperature in the presence of weak electric field E ≲ 50 V cm(-1), which originates from the obvious center-of-mass drift effect due to the weak electron-phonon interaction, whereas the hot-electron effect is demonstrated to be less important. This can explain the discrepancy between the experimental observation and the previous theoretical calculation (2012 Phys. Rev. B 86 085202), which deviates from the experimental results by about two orders of magnitude at low temperature. It is further shown that in the strong-electric-field regime with 0.5 ≲ E ≲ 2 kV cm(-1), the spin relaxation is enhanced due to the hot-electron effect, whereas the drift effect is demonstrated to be marginal. Finally, we find that when 1.4 ≲ E ≲ 2 kV cm(-1) which lies in the strong-electric-field regime, a small fraction of electrons (≲5%) can be driven from the L to Γ valley, and the spin relaxation rates are the same for the Γ and L valleys in the intrinsic sample without impurity. With the negligible influence of the spin dynamics in the Γ valley to the whole system, the spin dynamics in the L valley can be measured from the Γ valley by the standard direct optical transition method.

  3. Numerical simulation of neutral injection in a hot-electron mirror target plasma

    International Nuclear Information System (INIS)

    Werkoff, F.; Bardet, R.; Briand, P.; Dupas, L.; Gormezano, C.; Melin, G.; Association Euratom-CEA, Centre d'Etudes Nucleaires de Grenoble, 38

    1976-01-01

    In the case of neutral injection into a hot-electron target plasma, the use of the existing Fokker-Planck codes is greatly complicated by the fact that the scale of the energies and times of the confined ions and electrons is very large. To avoid this difficulty, a simplified multi-species model is set up, in which each species is described by time-dependent density and energy equations with analytical approximations for the interactions between the species. During the neutral injection, instantaneous high values of the ambipolar potential (higher than the half value of hot-ion energy) may appear, but do not prevent hot-ion density build-up. However, the hot-electron target plasma must not be maintained for a too long time. Numerical runs are performed with typical target parameters: density 2x10 13 cm -3 , electron energy 30 keV, ion energy 400 eV, time duration during which the target density is maintained 1 ms. Hot-ion density, a few 10 14 cm -3 , can be achieved with a neutral beam of 100 A, 20 keV. (author)

  4. Ultrafast Phase Transition in Vanadium Dioxide Driven by Hot-Electron Injection

    Directory of Open Access Journals (Sweden)

    Prasankumar R. P.

    2013-03-01

    Full Text Available We present a novel all-optical method of triggering the phase transition in vanadium dioxide by means of ballistic electrons injected across the interface between a mesh of Au nanoparticles coveringd VO2 nanoislands. By performing non-degenerate pump-probe transmission spectroscopy on this hybrid plasmonic/phase-changing nanostructure, structural and electronic dynamics can be retrieved and compared.

  5. Buildup of electrons with hot electron beam injection into a homogeneous magnetic field

    International Nuclear Information System (INIS)

    Bashko, V.A.; Krivoruchko, A.M.; Tarasov, I.K.

    1989-01-01

    The injection of the monoenergetic beam of electrons into the vacuum drift channel under the conditions when the beam current exceeds a certain threshold value involves a virtual cathode creation. The process of virtual cathode creation leads to an exchange of one-fluid movement of beam particles to three-fluid one corresponding to incident, reflected and passed through anticathode beam particles. For the monoenergetic beam case when the velocity spread Δv dr (v dr is the beam drift velocity), the beam instability was predicted in theory and was observed in experiment. Meanwhile, the injection in the drift space of the 'hot' beam having finite spread in velocities may be accompanied not only by the reflection of particles if their velocity v 1/2 (where φ is the electrostatic potential dip value, e and m are the electron charge and mass, respectively), but also the mutual Coulomb scattering of incident and reflected electrons. The scattering process leads in its turn to appearance of viscosity forces and to trapping of a part of beam electrons into the effective potential well formed by electrostatic potential dip and the viscous force potential. The interaction of travelling and trapped particles may occur even at the stage preceding the virtual electrode formation and it may influence the process of its appearance and also the current flow through the drift space. In this report there are described the experimental results on accumulation of electrons when electron beam propagates in vacuum and has a large spread in particle velocities Δv dr in the homogeneous longitudinal magnetic field when ω pe He where ω pe is the electron Langmuir frequency of beam electrons, ω He is the electron cyclotron frequency. (author) 6 refs., 2 figs

  6. Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

    Directory of Open Access Journals (Sweden)

    Kai Braun

    2015-05-01

    Full Text Available Here, we demonstrate a bias-driven superluminescent point light-source based on an optically pumped molecular junction (gold substrate/self-assembled molecular monolayer/gold tip of a scanning tunneling microscope, operating at ambient conditions and providing almost three orders of magnitude higher electron-to-photon conversion efficiency than electroluminescence induced by inelastic tunneling without optical pumping. A positive, steadily increasing bias voltage induces a step-like rise of the Stokes shifted optical signal emitted from the junction. This emission is strongly attenuated by reversing the applied bias voltage. At high bias voltage, the emission intensity depends non-linearly on the optical pump power. The enhanced emission can be modelled by rate equations taking into account hole injection from the tip (anode into the highest occupied orbital of the closest substrate-bound molecule (lower level and radiative recombination with an electron from above the Fermi level (upper level, hence feeding photons back by stimulated emission resonant with the gap mode. The system reflects many essential features of a superluminescent light emitting diode.

  7. Electron-electron scattering-induced channel hot electron injection in nanoscale n-channel metal-oxide-semiconductor field-effect-transistors with high-k/metal gate stacks

    International Nuclear Information System (INIS)

    Tsai, Jyun-Yu; Liu, Kuan-Ju; Lu, Ying-Hsin; Liu, Xi-Wen; Chang, Ting-Chang; Chen, Ching-En; Ho, Szu-Han; Tseng, Tseung-Yuen; Cheng, Osbert; Huang, Cheng-Tung; Lu, Ching-Sen

    2014-01-01

    This work investigates electron-electron scattering (EES)-induced channel hot electron (CHE) injection in nanoscale n-channel metal-oxide-semiconductor field-effect-transistors (n-MOSFETs) with high-k/metal gate stacks. Many groups have proposed new models (i.e., single-particle and multiple-particle process) to well explain the hot carrier degradation in nanoscale devices and all mechanisms focused on Si-H bond dissociation at the Si/SiO 2 interface. However, for high-k dielectric devices, experiment results show that the channel hot carrier trapping in the pre-existing high-k bulk defects is the main degradation mechanism. Therefore, we propose a model of EES-induced CHE injection to illustrate the trapping-dominant mechanism in nanoscale n-MOSFETs with high-k/metal gate stacks.

  8. Dynamics of Pierce instability of hot electron beams

    International Nuclear Information System (INIS)

    Ignatov, A.M.; Novikov, V.N.

    1986-01-01

    On the base of a new method of numerical solution of the Vlasov equation evolution of complete function of electron distribution at the injection of hot electron beams into plasma bounded with electrodes is investigated. It is shown that despite the development of electrostatic instabilities in the system the currents can run substantially exceeding the Pierce critical current

  9. Surface-Plasmon-Driven Hot Electron Photochemistry.

    Science.gov (United States)

    Zhang, Yuchao; He, Shuai; Guo, Wenxiao; Hu, Yue; Huang, Jiawei; Mulcahy, Justin R; Wei, Wei David

    2017-11-30

    Visible-light-driven photochemistry has continued to attract heightened interest due to its capacity to efficiently harvest solar energy and its potential to solve the global energy crisis. Plasmonic nanostructures boast broadly tunable optical properties coupled with catalytically active surfaces that offer a unique opportunity for solar photochemistry. Resonant optical excitation of surface plasmons produces energetic hot electrons that can be collected to facilitate chemical reactions. This review sums up recent theoretical and experimental approaches for understanding the underlying photophysical processes in hot electron generation and discusses various electron-transfer models on both plasmonic metal nanostructures and plasmonic metal/semiconductor heterostructures. Following that are highlights of recent examples of plasmon-driven hot electron photochemical reactions within the context of both cases. The review concludes with a discussion about the remaining challenges in the field and future opportunities for addressing the low reaction efficiencies in hot-electron-induced photochemistry.

  10. High frequency conductivity of hot electrons in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Amekpewu, M., E-mail: mamek219@gmail.com [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, S.Y. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Musah, R. [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, N.G. [Department of Mathematics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Abukari, S.S.; Dompreh, K.A. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana)

    2016-05-01

    High frequency conductivity of hot electrons in undoped single walled achiral Carbon Nanotubes (CNTs) under the influence of ac–dc driven fields was considered. We investigated semi-classically Boltzmann's transport equation with and without the presence of the hot electrons’ source by deriving the current densities in CNTs. Plots of the normalized current density versus frequency of ac-field revealed an increase in both the minimum and maximum peaks of normalized current density at lower frequencies as a result of a strong injection of hot electrons. The applied ac-field plays a twofold role of suppressing the space-charge instability in CNTs and simultaneously pumping an energy for lower frequency generation and amplification of THz radiations. These have enormous promising applications in very different areas of science and technology.

  11. Ponderomotive Acceleration of Hot Electrons in Tenuous Plasmas

    International Nuclear Information System (INIS)

    Geyko, V.I.; Fraiman, G.M.; Dodin, I.Y.; Fisch, N.J.

    2009-01-01

    The oscillation-center Hamiltonian is derived for a relativistic electron injected with an arbitrary momentum in a linearly polarized laser pulse propagating in tenuous plasma, assuming that the pulse length is smaller than the plasma wavelength. For hot electrons generated at collisions with ions under intense laser drive, multiple regimes of ponderomotive acceleration are identified and the laser dispersion is shown to affect the process at plasma densities down to 10 17 cm -3 . Assuming a/γ g 0 ∼ g , where a is the normalized laser field, and γ g is the group velocity Lorentz factor. Yet γ ∼ Γ is attained within a wide range of initial conditions; hence a cutoff in the hot electron distribution is predicted

  12. MIS hot electron devices for enhancement of surface reactivity by hot electrons

    DEFF Research Database (Denmark)

    Thomsen, Lasse Bjørchmar

    A Metal-Insulator-Semiconductor (MIS) based device is developed for investigation of hot electron enhanced chemistry. A model of the device is presented explaining the key concepts of the functionality and the character- istics. The MIS hot electron emitter is fabricated using cleanroom technology...... and the process sequence is described. An Ultra High Vacuum (UHV) setup is modified to facilitate experiments with electron emission from the MIS hot electron emitters and hot electron chemistry. Simulations show the importance of keeping tunnel barrier roughness to an absolute minimum. The tunnel oxide...... to be an important energy loss center for the electrons tunneling through the oxide lowering the emission e±ciency of a factor of 10 for a 1 nm Ti layer thickness. Electron emission is observed under ambient pressure conditions and in up to 2 bars of Ar. 2 bar Ar decrease the emission current by an order...

  13. Au nanoparticle-decorated silicon pyramids for plasmon-enhanced hot electron near-infrared photodetection

    Science.gov (United States)

    Qi, Zhiyang; Zhai, Yusheng; Wen, Long; Wang, Qilong; Chen, Qin; Iqbal, Sami; Chen, Guangdian; Xu, Ji; Tu, Yan

    2017-07-01

    The heterojunction between metal and silicon (Si) is an attractive route to extend the response of Si-based photodiodes into the near-infrared (NIR) region, so-called Schottky barrier diodes. Photons absorbed into a metallic nanostructure excite the surface plasmon resonances (SPRs), which can be damped non-radiatively through the creation of hot electrons. Unfortunately, the quantum efficiency of hot electron detectors remains low due to low optical absorption and poor electron injection efficiency. In this study, we propose an efficient and low-cost plasmonic hot electron NIR photodetector based on a Au nanoparticle (Au NP)-decorated Si pyramid Schottky junction. The large-area and lithography-free photodetector is realized by using an anisotropic chemical wet etching and rapid thermal annealing (RTA) of a thin Au film. We experimentally demonstrate that these hot electron detectors have broad photoresponsivity spectra in the NIR region of 1200-1475 nm, with a low dark current on the order of 10-5 A cm-2. The observed responsivities enable these devices to be competitive with other reported Si-based NIR hot electron photodetectors using perfectly periodic nanostructures. The improved performance is attributed to the pyramid surface which can enhance light trapping and the localized electric field, and the nano-sized Au NPs which are beneficial for the tunneling of hot electrons. The simple and large-area preparation processes make them suitable for large-scale thermophotovoltaic cell and low-cost NIR detection applications.

  14. Plasmonically enhanced hot electron based photovoltaic device.

    Science.gov (United States)

    Atar, Fatih B; Battal, Enes; Aygun, Levent E; Daglar, Bihter; Bayindir, Mehmet; Okyay, Ali K

    2013-03-25

    Hot electron photovoltaics is emerging as a candidate for low cost and ultra thin solar cells. Plasmonic means can be utilized to significantly boost device efficiency. We separately form the tunneling metal-insulator-metal (MIM) junction for electron collection and the plasmon exciting MIM structure on top of each other, which provides high flexibility in plasmonic design and tunneling MIM design separately. We demonstrate close to one order of magnitude enhancement in the short circuit current at the resonance wavelengths.

  15. Going ballistic: Graphene hot electron transistors

    Science.gov (United States)

    Vaziri, S.; Smith, A. D.; Östling, M.; Lupina, G.; Dabrowski, J.; Lippert, G.; Mehr, W.; Driussi, F.; Venica, S.; Di Lecce, V.; Gnudi, A.; König, M.; Ruhl, G.; Belete, M.; Lemme, M. C.

    2015-12-01

    This paper reviews the experimental and theoretical state of the art in ballistic hot electron transistors that utilize two-dimensional base contacts made from graphene, i.e. graphene base transistors (GBTs). Early performance predictions that indicated potential for THz operation still hold true today, even with improved models that take non-idealities into account. Experimental results clearly demonstrate the basic functionality, with on/off current switching over several orders of magnitude, but further developments are required to exploit the full potential of the GBT device family. In particular, interfaces between graphene and semiconductors or dielectrics are far from perfect and thus limit experimental device integrity, reliability and performance.

  16. Experiments on hot-electron ECRH in the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Stallard, B.W.

    1983-01-01

    Experiments have begun on the Tandem Mirror Experiment Upgrade (TMX-U) using electron-cyclotron resonant heating (ECRH) to generate the hot electron populations required for thermal barrier operation (Energy E/sub eh/ approx. 50 keV, density n/sub eh/ 12 , and hot-to-cold fraction n/sub eh/n approx. 0.9). For this operation, rf power produced by 28-GHz gyrotrons is injected with extraordinary mode polarization at both fundamental and second harmonic locations. Our initial experiments, which concentrated on startup of the hot electrons, were carried out at low density ( 12 cm - 3 ) where Fokker-Planck calculations predict high heating efficiency when the electron temperature (T/sub e/) is low. Under these conditions, we produced substantial hot electron populations (diamagnetic energy > 400 J, E/sub eh/ in the range of 15 to 50 keV, and n/sub eh//n > 0.5)

  17. Hot Electron Nanoscopy and Spectroscopy (HENs)

    KAUST Repository

    Giugni, Andrea; Torre, Bruno; Allione, Marco; Perozziello, Gerardo; Candeloro, Patrizio; Di Fabrizio, Enzo M.

    2017-01-01

    This chapter includes a brief description of different laser coupling methods with guided surface plasmon polariton (SPP) modes at the surface of a cone. It shows some devices, their electromagnetic simulations, and their optical characterization. A theoretical section illustrates the optical and quantum description of the hot charge generation rate as obtained for the SPP propagation along the nanocone in adiabatic compression. The chapter also shows some experimental results concerning the application of the hot electron nanoscopy and spectroscopy (HENs) in the so-called Schottky configuration, highlighting the sensitivity and the nanoscale resolution of the technique. The comparison with Kelvin probe and other electric atomic force microscopy (AFM) techniques points out the intrinsic advantages of the HENs. In the end, some further insights are given about the possibility of exploiting HENs with a pulsed laser at the femtosecond time scale without significant pulse broadening and dispersion.

  18. Superconducting cuprate heterostructures for hot electron bolometers

    Science.gov (United States)

    Wen, B.; Yakobov, R.; Vitkalov, S. A.; Sergeev, A.

    2013-11-01

    Transport properties of the resistive state of quasi-two dimensional superconducting heterostructures containing ultrathin La2-xSrxCuO4 layers synthesized using molecular beam epitaxy are studied. The electron transport exhibits strong deviation from Ohm's law, δV ˜γI3, with a coefficient γ(T) that correlates with the temperature variation of the resistivity dρ /dT. Close to the normal state, analysis of the nonlinear behavior in terms of electron heating yields an electron-phonon thermal conductance per unit area ge -ph≈1 W/K cm2 at T = 20 K, one-two orders of magnitude smaller than in typical superconductors. This makes superconducting LaSrCuO heterostructures to be attractive candidate for the next generation of hot electron bolometers with greatly improved sensitivity.

  19. Superconducting cuprate heterostructures for hot electron bolometers

    International Nuclear Information System (INIS)

    Wen, B.; Yakobov, R.; Vitkalov, S. A.; Sergeev, A.

    2013-01-01

    Transport properties of the resistive state of quasi-two dimensional superconducting heterostructures containing ultrathin La 2−x Sr x CuO 4 layers synthesized using molecular beam epitaxy are studied. The electron transport exhibits strong deviation from Ohm's law, δV∼γI 3 , with a coefficient γ(T) that correlates with the temperature variation of the resistivity dρ/dT. Close to the normal state, analysis of the nonlinear behavior in terms of electron heating yields an electron-phonon thermal conductance per unit area g e−ph ≈1 W/K cm 2 at T = 20 K, one-two orders of magnitude smaller than in typical superconductors. This makes superconducting LaSrCuO heterostructures to be attractive candidate for the next generation of hot electron bolometers with greatly improved sensitivity

  20. Hot Electron Nanoscopy and Spectroscopy (HENs)

    KAUST Repository

    Giugni, Andrea

    2017-08-17

    This chapter includes a brief description of different laser coupling methods with guided surface plasmon polariton (SPP) modes at the surface of a cone. It shows some devices, their electromagnetic simulations, and their optical characterization. A theoretical section illustrates the optical and quantum description of the hot charge generation rate as obtained for the SPP propagation along the nanocone in adiabatic compression. The chapter also shows some experimental results concerning the application of the hot electron nanoscopy and spectroscopy (HENs) in the so-called Schottky configuration, highlighting the sensitivity and the nanoscale resolution of the technique. The comparison with Kelvin probe and other electric atomic force microscopy (AFM) techniques points out the intrinsic advantages of the HENs. In the end, some further insights are given about the possibility of exploiting HENs with a pulsed laser at the femtosecond time scale without significant pulse broadening and dispersion.

  1. Flute-interchange stability in a hot electron plasma

    International Nuclear Information System (INIS)

    Dominguez, R.R.

    1980-01-01

    Several topics in the kinetic stability theory of flute-interchange modes in a hot electron plasma are discussed. The stability analysis of the hot-electron, curvature-driven flute-interchange mode, previously performed in a slab geometry, is extended to a cylindrical plasma. The cold electron concentration necessary for stability differs substantially from previous criteria. The inclusion of a finite temperature background plasma in the stability analysis results in an ion curvature-driven flute-interchange mode which may be stabilized by either hot-electron diamagnetic effects, hot-electron plasma density, or finite (ion) Larmor radius effects

  2. Simulation studies on stability of hot electron plasma

    International Nuclear Information System (INIS)

    Ohsawa, Yukiharu

    1985-01-01

    Stability of a hot electron plasma in an NBT(EBT)-like geometry is studied by using a 2-1/2 dimensional relativistic, electromagnetic particle code. For the low-frequency hot electron interchange mode, comparison of the simulation results with the analytical predictions of linear stability theory show fairly good agreement with the magnitude of the growth rates calculated without hot electron finite Larmor radius effects. Strong stabilizing effects by finite Larmor radius of the hot electrons are observed for short wavelength modes. As for the high-frequency hot electron interchange mode, there is a discrepancy between the simulation results and the theory. The high-frequency instability is not observed though a parameter regime is chosen in which the high-frequency hot electron interchange mode is theoretically predicted to grow. Strong cross-field diffusion in a poloidal direction of the hot electrons might explain the stability. Each particle has a magnetic drift velocity, and the speed of the magnetic drift is proportional to the kinetic energy of each particle. Hence, if the particles have high temperature, the spread of the magnetic drift velocity is large. This causes a strong cross-field diffusion of the hot electrons. In the simulation for this interchange mode, an enhanced temperature relaxation is observed between the hot and cold electrons although the theoretically predicted high frequency modes are stable. (Nogami, K.)

  3. Hot electron effect in the dc SQUID

    International Nuclear Information System (INIS)

    Wellstood, F.C.; Clarke, J.; Urbina, C.

    1989-01-01

    The authors have investigated the temperature dependence of the noise in thin-film dc Superconducting Quantum Interference Devices (SQUIDs) down to 20 mK. The white noise measured in the early versions of our SQUIDs did not decrease as the bath temperature was lowered below 150 mK. They have attributed this saturation to a hot electron effect in the thin-film AuCu resistors shunting the Josephson junctions. A theoretical investigation showed that the temperature of the electrons in the shunts should be given by T/sub e/ = (P/ΣΩ)/sup 1/5/, where P is the power dissipated in the shunts, Ω is the shunt volume, and Σ is a proportionality constant. Experimentally, the authors found Σ=(2.4+-0.6)X10/sup 9/WK/sup -5/m/sup -3/. They have redesigned the shunts, adding large thin-film cooling fins, to increase their volume substantially. This technique has reduced T/sub e/ to about 50 mK, with a corresponding improvement in the sensitivity of the SQUIDs

  4. Operation of a novel hot-electron vertical-cavity surface-emitting laser

    Science.gov (United States)

    Balkan, Naci; O'Brien-Davies, Angela; Thoms, A. B.; Potter, Richard J.; Poolton, Nigel; Adams, Michael J.; Masum, J.; Bek, Alpan; Serpenguzel, Ali; Aydinli, Atilla; Roberts, John S.

    1998-07-01

    The hot Electron Light Emission and Lasing in Semiconductor Heterostructures devices (HELLISH-1) is novel surface emitter consisting of a GaAs quantum well, within the depletion region, on the n side of Ga1-xAlxAs p- n junction. It utilizes hot electron transport parallel to the layers and injection of hot electron hole pairs into the quantum well through a combination of mechanisms including tunnelling, thermionic emission and diffusion of `lucky' carriers. Super Radiant HELLISH-1 is an advanced structure incorporating a lower distributed Bragg reflector (DBR). Combined with the finite reflectivity of the upper semiconductor-air interface reflectivity it defines a quasi- resonant cavity enabling emission output from the top surface with a higher spectral purity. The output power has increased by two orders of magnitude and reduced the full width at half maximum (FWHM) to 20 nm. An upper DBR added to the structure defines HELLISH-VCSEL which is currently the first operational hot electron surface emitting laser and lases at room temperature with a 1.5 nm FWHM. In this work we demonstrate and compare the operation of UB-HELLISH-1 and HELLISH-VCSEL using experimental and theoretical reflectivity spectra over an extensive temperature range.

  5. Interplay of hot electrons from localized and propagating plasmons.

    Science.gov (United States)

    Hoang, Chung V; Hayashi, Koki; Ito, Yasuo; Gorai, Naoki; Allison, Giles; Shi, Xu; Sun, Quan; Cheng, Zhenzhou; Ueno, Kosei; Goda, Keisuke; Misawa, Hiroaki

    2017-10-03

    Plasmon-induced hot-electron generation has recently received considerable interest and has been studied to develop novel applications in optoelectronics, photovoltaics and green chemistry. Such hot electrons are typically generated from either localized plasmons in metal nanoparticles or propagating plasmons in patterned metal nanostructures. Here we simultaneously generate these heterogeneous plasmon-induced hot electrons and exploit their cooperative interplay in a single metal-semiconductor device to demonstrate, as an example, wavelength-controlled polarity-switchable photoconductivity. Specifically, the dual-plasmon device produces a net photocurrent whose polarity is determined by the balance in population and directionality between the hot electrons from localized and propagating plasmons. The current responsivity and polarity-switching wavelength of the device can be varied over the entire visible spectrum by tailoring the hot-electron interplay in various ways. This phenomenon may provide flexibility to manipulate the electrical output from light-matter interaction and offer opportunities for biosensors, long-distance communications, and photoconversion applications.Plasmon-induced hot electrons have potential applications spanning photodetection and photocatalysis. Here, Hoang et al. study the interplay between hot electrons generated by localized and propagating plasmons, and demonstrate wavelength-controlled polarity-switchable photoconductivity.

  6. Surface and volume photoemission of hot electrons from plasmonic nanoantennas

    DEFF Research Database (Denmark)

    Uskov, Alexander V.; Protsenko, Igor E.; Ikhsanov, Renat S.

    2014-01-01

    We theoretically compare surface- and volume-based photoelectron emission from spherical nanoparticles, obtaining analytical expressions for the emission rate in both mechanisms. We show that the surface mechanism prevails, being unaffected by detrimental hot electron collisions.......We theoretically compare surface- and volume-based photoelectron emission from spherical nanoparticles, obtaining analytical expressions for the emission rate in both mechanisms. We show that the surface mechanism prevails, being unaffected by detrimental hot electron collisions....

  7. Hot-electron nanoscopy using adiabatic compression of surface plasmons

    KAUST Repository

    Giugni, Andrea

    2013-10-20

    Surface plasmon polaritons are a central concept in nanoplasmonics and have been exploited to develop ultrasensitive chemical detection platforms, as well as imaging and spectroscopic techniques at the nanoscale. Surface plasmons can decay to form highly energetic (or hot) electrons in a process that is usually thought to be parasitic for applications, because it limits the lifetime and propagation length of surface plasmons and therefore has an adverse influence on the functionality of nanoplasmonic devices. Recently, however, it has been shown that hot electrons produced by surface plasmon decay can be harnessed to produce useful work in photodetection, catalysis and solar energy conversion. Nevertheless, the surface-plasmon-to-hot-electron conversion efficiency has been below 1% in all cases. Here we show that adiabatic focusing of surface plasmons on a Schottky diode-terminated tapered tip of nanoscale dimensions allows for a plasmon-to-hot-electron conversion efficiency of ∼30%. We further demonstrate that, with such high efficiency, hot electrons can be used for a new nanoscopy technique based on an atomic force microscopy set-up. We show that this hot-electron nanoscopy preserves the chemical sensitivity of the scanned surface and has a spatial resolution below 50 nm, with margins for improvement.

  8. Hot-electron nanoscopy using adiabatic compression of surface plasmons

    KAUST Repository

    Giugni, Andrea; Torre, Bruno; Toma, Andrea; Francardi, Marco; Malerba, Mario; Alabastri, Alessandro; Proietti Zaccaria, Remo; Stockman, Mark Mark; Di Fabrizio, Enzo M.

    2013-01-01

    Surface plasmon polaritons are a central concept in nanoplasmonics and have been exploited to develop ultrasensitive chemical detection platforms, as well as imaging and spectroscopic techniques at the nanoscale. Surface plasmons can decay to form highly energetic (or hot) electrons in a process that is usually thought to be parasitic for applications, because it limits the lifetime and propagation length of surface plasmons and therefore has an adverse influence on the functionality of nanoplasmonic devices. Recently, however, it has been shown that hot electrons produced by surface plasmon decay can be harnessed to produce useful work in photodetection, catalysis and solar energy conversion. Nevertheless, the surface-plasmon-to-hot-electron conversion efficiency has been below 1% in all cases. Here we show that adiabatic focusing of surface plasmons on a Schottky diode-terminated tapered tip of nanoscale dimensions allows for a plasmon-to-hot-electron conversion efficiency of ∼30%. We further demonstrate that, with such high efficiency, hot electrons can be used for a new nanoscopy technique based on an atomic force microscopy set-up. We show that this hot-electron nanoscopy preserves the chemical sensitivity of the scanned surface and has a spatial resolution below 50 nm, with margins for improvement.

  9. Current gain above 10 in sub-10 nm base III-Nitride tunneling hot electron transistors with GaN/AlN emitter

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhichao, E-mail: zcyang.phys@gmail.com; Zhang, Yuewei; Krishnamoorthy, Sriram; Nath, Digbijoy N. [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Khurgin, Jacob B. [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2016-05-09

    We report on a tunneling hot electron transistor amplifier with common-emitter current gain greater than 10 at a collector current density in excess of 40 kA/cm{sup 2}. The use of a wide-bandgap GaN/AlN (111 nm/2.5 nm) emitter was found to greatly improve injection efficiency of the emitter and reduce cold electron leakage. With an ultra-thin (8 nm) base, 93% of the injected hot electrons were collected, enabling a common-emitter current gain up to 14.5. This work improves understanding of the quasi-ballistic hot electron transport and may impact the development of high speed devices based on unipolar hot electron transport.

  10. Study of hot electrons in a ECR ion source

    International Nuclear Information System (INIS)

    Barue, C.

    1992-12-01

    The perfecting of diagnosis connected with hot electrons of plasma, and then the behaviour of measured parameters of plasma according to parameters of source working are the purpose of this thesis. The experimental results obtained give new information on hot electrons of an ECR ion source. This thesis is divided in 4 parts: the first part presents an ECR source and the experimental configuration (ECRIS physics, minimafios GHz, diagnosis used); the second part, the diagnosis (computer code of cyclotron emission and calibration); the third part gives experimental results in continuous regime (emission cyclotron diagnosis, bremsstrahlung); the fourth part, experimental results in pulsed regime (emission cyclotron diagnosis, diamagnetism) calibration)

  11. Role of hot electron transport in scintillators: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Huihui [SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Lab. of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen Univ. (China); Li, Qi [Physical Sciences Division, IBM TJ Watson Research Center, Yorktown Heights, NY (United States); Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Lu, Xinfu; Williams, R.T. [Department of Physics, Wake Forest University, Winston Salem, NC (United States); Qian, Yiyang [College of Engineering and Applied Science, Nanjing University (China); Wu, Yuntao [Scintillation Materials Research Center, University of Tennessee, Knoxville, TN (United States)

    2016-10-15

    Despite recent intensive study on scintillators, several fundamental questions on scintillator properties are still unknown. In this work, we use ab-initio calculations to determine the energy dependent group velocity of the hot electrons from the electronic structures of several typical scintillators. Based on the calculated group velocities and optical phonon frequencies, a Monte-Carlo simulation of hot electron transport in scintillators is carried out to calculate the thermalization time and diffusion range in selected scintillators. Our simulations provide physical insights on a recent trend of improved proportionality and light yield from mixed halide scintillators. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Quantum noise in a terahertz hot electron bolometer mixer

    NARCIS (Netherlands)

    Zhang, W.; Khosropanah, P.; Gao, J. R.; Kollberg, E. L.; Yngvesson, K. S.; Bansal, T.; Barends, R.; Klapwijk, T. M.

    2010-01-01

    We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model

  13. Ultrafast Hot Electron Induced Phase Transitions in Vanadium Dioxide

    Directory of Open Access Journals (Sweden)

    Haglund R. F.

    2013-03-01

    Full Text Available The Au/Cr/VO2/Si system was investigated in pump–probe experiments. Hot-electrons generated in the Au were found to penetrate into the underlying VO2 and couple with its lattice inducing a semiconductor-to-metal phase transition in ~2 picoseconds.

  14. Heat transfer between adsorbate and laser-heated hot electrons

    International Nuclear Information System (INIS)

    Ueba, H; Persson, B N J

    2008-01-01

    Strong short laser pulses can give rise to a strong increase in the electronic temperature at metal surfaces. Energy transfer from the hot electrons to adsorbed molecules may result in adsorbate reactions, e.g. desorption or diffusion. We point out the limitations of an often used equation to describe the heat transfer process in terms of a friction coupling. We propose a simple theory for the energy transfer between the adsorbate and hot electrons using a newly introduced heat transfer coefficient, which depends on the adsorbate temperature. We calculate the transient adsorbate temperature and the reaction yield for a Morse potential as a function of the laser fluency. The results are compared to those obtained using a conventional heat transfer equation with temperature-independent friction. It is found that our equation of energy (heat) transfer gives a significantly lower adsorbate peak temperature, which results in a large modification of the reaction yield. We also consider the heat transfer between different vibrational modes excited by hot electrons. This mode coupling provides indirect heating of the vibrational temperature in addition to the direct heating by hot electrons. The formula of heat transfer through linear mode-mode coupling of two harmonic oscillators is applied to the recent time-resolved study of carbon monoxide and atomic oxygen hopping on an ultrafast laser-heated Pt(111) surface. It is found that the maximum temperature of the frustrated translation mode can reach high temperatures for hopping, even when direct friction coupling to the hot electrons is not strong enough

  15. An experimental determination of the hot electron ring geometry in a Bumpy Torus and its implications for Bumpy Torus stability

    International Nuclear Information System (INIS)

    Hillis, D.L.; Wilgen, J.B.; Bigelow, T.S.; Jaeger, E.F.; Swain, D.W.; Hankins, O.E.; Juhala, R.E.

    1986-10-01

    The hot electron rings of the ELMO Bumpy Torus (EBT) [Plasma Physics and Controlled Nuclear Fusion (IAEA, Vienna, 1975), Vol. II, p. 141] are formed by electron cyclotron resonance heating (ECRH) and have an electron temperature of 350 to 500 keV. The original intention of these hot electron rings was to provide a local minimum in the magnetic field and, thereby, stabilize the simple interchange and flute modes, which are inherent in a closed field line bumpy torus. To evaluate the electron energy density of the EBT rings and determine if enough stored energy is present to provide a local minimum in the magnetic field, a detailed understanding of the spatial distribution of the rings is imperative. The purpose of this report is to measure the ring thickness and investigate its implications for bumpy torus stability. The spatial location and radial profile of the hot electron ring are measured with a unique metal ball pellet injector, which injects small metallic balls into the EBT ring plasma. From these measurements the radial extent (or ring thickness) is about 5 to 7 cm full width at half maximum for typical EBT operation, which is much larger than previously expected. These measurements and recent modeling of the EBT plasma indicate that the hot electron ring's stored energy may not be sufficient to produce a local minimum in the magnetic field

  16. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  17. Stimulated Raman scattering and hot-electron production

    International Nuclear Information System (INIS)

    Drake, R.P.; Turner, R.E.; Lasinski, B.F.; Estabrook, K.G.; Campbell, E.M.; Wang, C.L.; Phillion, D.W.; Williams, E.A.; Kruer, W.L.

    1985-01-01

    High-intensity laser light can excite parametric instabilities that scatter or absorb it. One instability that can arise when laser light penetrates a plasma is sub-quarter-critical stimulated Raman (SQSR) scattering. It occurs below the quarter-critical density of the incident light and involves the decay of the incident light wave into a scattered light wave and electron plasma wave. The scattered-light wavelength ranges from 1 to 2 times that of the incident light, depending on the plasma density and temperature. This article reports studies of SQSR scattering and hot-electron production in plasmas produced by irradiating thick gold targets with up to 4 kJ of 0.53-μm light in 1-ns (FWHM) pulses. These studies have important implications for laser fusion. Hot electrons attributed to the SQSR instability can increase the difficulty of achieving high-gain implosions by penetrating and preheating the fusion fuel

  18. Nonequilibrium statistical operator in hot-electron transport theory

    International Nuclear Information System (INIS)

    Xing, D.Y.; Liu, M.

    1991-09-01

    The Nonequilibrium Statistical Operator method developed by Zubarev is generalized and applied to the study of hot-electron transport in semiconductors. The steady-state balance equations for momentum and energy are derived to the lowest order in the electron-lattice coupling. We show that the derived balance equations are exactly the same as those obtained by Lei and Ting. This equivalence stems from the fact that to the linear order in the electron-lattice coupling, two statistical density matrices have identical effect when they are used to calculate the average value of a dynamical operator. The application to the steady-state and transient hot-electron transport in multivalley semiconductors is also discussed. (author). 28 refs, 1 fig

  19. Terahertz hot electron bolometer waveguide mixers for GREAT

    OpenAIRE

    Pütz, P.; Honingh, C. E.; Jacobs, K.; Justen, M.; Schultz, M.; Stutzki, J.

    2012-01-01

    Supplementing the publications based on the first-light observations with the German Receiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on the...

  20. Enhanced energy deposition symmetry by hot electron transport

    International Nuclear Information System (INIS)

    Wilson, D.; Mack, J.; Stover, E.; VanHulsteyn, D.; McCall, G.; Hauer, A.

    1981-01-01

    High energy electrons produced by resonance absorption carry the CO 2 laser energy absorbed in a laser fusion pellet. The symmetrization that can be achieved by lateral transport of the hot electrons as they deposit their energy is discussed. A K/sub α/ experiment shows a surprising symmetrization of energy deposition achieved by adding a thin layer of plastic to a copper sphere. Efforts to numerically model this effect are described

  1. Ab initio study of hot electrons in GaAs

    OpenAIRE

    Bernardi, Marco; Vigil-Fowler, Derek; Ong, Chin Shen; Neaton, Jeffrey B.; Louie, Steven G.

    2015-01-01

    Hot carrier dynamics critically impacts the performance of electronic, optoelectronic, photovoltaic, and plasmonic devices. Hot carriers lose energy over nanometer lengths and picosecond timescales and thus are challenging to study experimentally, whereas calculations of hot carrier dynamics are cumbersome and dominated by empirical approaches. In this work, we present ab initio calculations of hot electrons in gallium arsenide (GaAs) using density functional theory and many-body perturbation...

  2. Establishment of design space for high current gain in III-N hot electron transistors

    Science.gov (United States)

    Gupta, Geetak; Ahmadi, Elaheh; Suntrup, Donald J., III; Mishra, Umesh K.

    2018-01-01

    This paper establishes the design space of III-N hot electron transistors (HETs) for high current gain by designing and fabricating HETs with scaled base thickness. The device structure consists of GaN-based emitter, base and collector regions where emitter and collector barriers are implemented using AlN and InGaN layers, respectively, as polarization-dipoles. Electrons tunnel through the AlN layer to be injected into the base at a high energy where they travel in a quasi-ballistic manner before being collected. Current gain increases from 1 to 3.5 when base thickness is reduced from 7 to 4 nm. The extracted mean free path (λ mfp) is 5.8 nm at estimated injection energy of 1.5 eV.

  3. A model for hot electron phenomena: Theory and general results

    International Nuclear Information System (INIS)

    Carrillo, J.L.; Rodriquez, M.A.

    1988-10-01

    We propose a model for the description of the hot electron phenomena in semiconductors. Based on this model we are able to reproduce accurately the main characteristics observed in experiments of electric field transport, optical absorption, steady state photoluminescence and relaxation process. Our theory does not contain free nor adjustable parameters, it is very fast computerwise, and incorporates the main collision mechanisms including screening and phonon heating effects. Our description on a set of nonlinear rate equations in which the interactions are represented by coupling coefficients or effective frequencies. We calculate three coefficients from the characteristic constants and the band structure of the material. (author). 22 refs, 5 figs, 1 tab

  4. Antenna-coupled 30 THz hot electron bolometer mixers

    OpenAIRE

    Shcherbatenko, M.; Lobanov, Y.; Benderov, O.; Shurakov, A.; Ignatov, A.; Titova, N.; Finkel, M.; Maslennikov, S.; Kaurova, N.; Voronov, B.M.; Rodin, A.; Klapwijk, T.M.; Gol'tsman, G.N.

    2015-01-01

    We report on design and characterization of a superconducting Hot Electron Bolometer Mixer integrated with a logarithmic spiral antenna for mid-IR range observations. The antenna parameters have been adjusted to achieve the ultimate performance at 10 ?m (30 THz) range where O3, NH3, CO2, CH4, N2O, …. lines in the Earth’s atmosphere, in planetary atmospheres and in the interstellar space can be observed. The HEB mixer is made of a thin NbN film deposited onto a GaAs substrate. To couple the ra...

  5. Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

    Science.gov (United States)

    Skalare, Anders; McGrath, William; Bumble, Bruce; LeDuc, Henry

    2004-01-01

    A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/normal- conducting transition in a thin strip of niobium and that was described elsewhere.

  6. Quantum noise in a terahertz hot electron bolometer mixer

    OpenAIRE

    Zhang, W.; Khosropanah, P.; Gao, J. R.; Kollberg, E. L.; Yngvesson, K. S.; Bansal, T.; Barends, R.; Klapwijk, T. M.

    2010-01-01

    We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model for HEB mixers, we confirm the effect of QN. The QN is found to be responsible for about half of the receiver noise at the highest frequency in our measurements. The ?-factor (the quantum efficiency ...

  7. High-frequency microinstabilities in hot-electron plasmas

    International Nuclear Information System (INIS)

    Chen, Y.J.; Nevins, W.M.; Smith, G.R.

    1981-01-01

    Instabilities with frequencies in the neighborhood of the electron cyclotron frequency are of interest in determining stable operating regimes of hot-electron plasmas in EBT devices and in tandem mirrors. Previous work used model distributions significantly different than those suggested by recent Fokker-Planck studies. We use much more realistic model distributions in a computer code that solves the full electromagnetic dispersion relation governing longitudinal and transverse waves in a uniform plasma. We allow for an arbitrary direction of wave propagation. Results for the whistler and upper-hybrid loss-cone instabilities are presented

  8. Superconducting hot-electron bolometer: from the discovery of hot-electron phenomena to practical applications

    International Nuclear Information System (INIS)

    Shurakov, A; Lobanov, Y; Goltsman, G

    2016-01-01

    The discovery of hot-electron phenomena in a thin superconducting film in the last century was followed by numerous experimental studies of its appearance in different materials aiming for a better understanding of the phenomena and consequent implementation of terahertz detection systems for practical applications. In contrast to the competitors such as superconductor-insulator-superconductor tunnel junctions and Schottky diodes, the hot electron bolometer (HEB) did not demonstrate any frequency limitation of the detection mechanism. The latter, in conjunction with a decent performance, rapidly made the HEB mixer the most attractive candidate for heterodyne observations at frequencies above 1 THz. The successful operation of practical instruments (the Heinrich Hertz Telescope, the Receiver Lab Telescope, APEX, SOFIA, Hershel) ensures the importance of the HEB technology despite the lack of rigorous theoretical routine for predicting the performance. In this review, we provide a summary of experimental and theoretical studies devoted to understanding the HEB physics, and an overview of various fabrication routes and materials. (topical review)

  9. Stabilizing effects of hot electrons on low frequency plasma drift waves

    International Nuclear Information System (INIS)

    Huang Chaosong; Qiu Lijian; Ren Zhaoxing

    1988-01-01

    The MHD equation is used to study the stabilization of low frequency drift waves driven by density gradient of plasma in a hot electron plasma. The dispersion relation is derived, and the stabilizing effects of hot electrons are discussed. The physical mechanism for hot electron stabilization of the low frequency plasma perturbations is charge uncovering due to the hot electron component, which depends only on α, the ratio of N h /N i , but not on the value of β h . The hot electrons can reduce the growth rate of the interchange mode and drift wave driven by the plasma, and suppress the enomalous plasma transport caused by the drift wave. Without including the effectof β h , the stabilization of the interchange mode requires α≅2%, and the stabilization of the drift wave requires α≅40%. The theoretical analyses predict that the drift wave is the most dangerous low frequency instability in the hot electron plasma

  10. Fast Advection of Magnetic Fields by Hot Electrons

    International Nuclear Information System (INIS)

    Willingale, L.; Thomas, A. G. R.; Krushelnick, K.; Nilson, P. M.; Kaluza, M. C.; Dangor, A. E.; Evans, R. G.; Fernandes, P.; Haines, M. G.; Kamperidis, C.; Kingham, R. J.; Ridgers, C. P.; Sherlock, M.; Wei, M. S.; Najmudin, Z.; Bandyopadhyay, S.; Notley, M.; Minardi, S.; Tatarakis, M.; Rozmus, W.

    2010-01-01

    Experiments where a laser-generated proton beam is used to probe the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target are presented. At intensities of 10 15 W cm -2 and under conditions of significant fast electron production and strong heat fluxes, the electron mean-free-path is long compared with the temperature gradient scale length and hence nonlocal transport is important for the dynamics of the magnetic field in the plasma. The hot electron flux transports self-generated magnetic fields away from the focal region through the Nernst effect [A. Nishiguchi et al., Phys. Rev. Lett. 53, 262 (1984)] at significantly higher velocities than the fluid velocity. Two-dimensional implicit Vlasov-Fokker-Planck modeling shows that the Nernst effect allows advection and self-generation transports magnetic fields at significantly faster than the ion fluid velocity, v N /c s ≅10.

  11. The development of terahertz superconducting hot-electron bolometric mixers

    International Nuclear Information System (INIS)

    Semenov, Alexei; Richter, Heiko; Smirnov, Konstantin; Voronov, Boris; Gol'tsman, Gregory; Huebers, Heinz-Wilhelm

    2004-01-01

    We present recent advances in the development of NbN hot-electron bolometric (HEB) mixers for flying terahertz heterodyne receivers. Three important issues have been addressed: the quality of the source NbN films, the effect of the bolometer size on the spectral properties of different planar feed antennas, and the local oscillator (LO) power required for optimal operation of the mixer. Studies of the NbN films with an atomic force microscope indicated a surface structure that may affect the performance of the smallest mixers. Measured spectral gain and noise temperature suggest that at frequencies above 2.5 THz the spiral feed provides better overall performance than the double-slot feed. Direct measurements of the optimal LO power support earlier estimates made in the framework of the uniform mixer model

  12. Modelling hot electron generation in short pulse target heating experiments

    Directory of Open Access Journals (Sweden)

    Sircombe N.J.

    2013-11-01

    Full Text Available Target heating experiments planned for the Orion laser facility, and electron beam driven fast ignition schemes, rely on the interaction of a short pulse high intensity laser with dense material to generate a flux of energetic electrons. It is essential that the characteristics of this electron source are well known in order to inform transport models in radiation hydrodynamics codes and allow effective evaluation of experimental results and forward modelling of future campaigns. We present results obtained with the particle in cell (PIC code EPOCH for realistic target and laser parameters, including first and second harmonic light. The hot electron distributions are characterised and their implications for onward transport and target heating are considered with the aid of the Monte-Carlo transport code THOR.

  13. Hot Electron Generation and Transport Using Kα Emission

    International Nuclear Information System (INIS)

    Akli, K.U.; Stephens, R.B.; Key, M.H.; Bartal, T.; Beg, F.N.; Chawla, S.; Chen, C.D.; Fedosejevs, R.; Freeman, R.R.; Friesen, H.; Giraldez, E.; Green, J.S.; Hey, D.S.; Higginson, D.P.; Hund, J.; Jarrott, L.C.; Kemp, G.E.; King, J.A.; Kryger, A.; Lancaster, K.; LePape, S.; Link, A.; Ma, T.; Mackinnon, A.J.; MacPhee, A.G.; McLean, H.S.; Murphy, C.; Norreys, P.A.; Ovchinnikov, V.; Patel, P.K.; Ping, Y.; Sawada, H.; Schumacher, D.; Theobald, W.; Tsui, Y.Y.; Van Woerkom, L.D.; Wei, M.S.; Westover, B.; Yabuuchi, T.

    2010-01-01

    We have conducted experiments on both the Vulcan and Titan laser facilities to study hot electron generation and transport in the context of fast ignition. Cu wires attached to Al cones were used to investigate the effect on coupling efficiency of plasma surround and the pre-formed plasma inside the cone. We found that with thin cones 15% of laser energy is coupled to the 40(micro)m diameter wire emulating a 40(micro)m fast ignition spot. Thick cone walls, simulating plasma in fast ignition, reduce coupling by x4. An increase of prepulse level inside the cone by a factor of 50 reduces coupling by a factor of 3.

  14. Nonplasmonic Hot-Electron Photocurrents from Mn-Doped Quantum Dots in Photoelectrochemical Cells.

    Science.gov (United States)

    Dong, Yitong; Rossi, Daniel; Parobek, David; Son, Dong Hee

    2016-03-03

    We report the measurement of the hot-electron current in a photoelectrochemical cell constructed from a glass/ITO/Al2 O3 (ITO=indium tin oxide) electrode coated with Mn-doped quantum dots, where hot electrons with a large excess kinetic energy were produced through upconversion of the excitons into hot electron hole pairs under photoexcitation at 3 eV. In our recent study (J. Am. Chem. Soc. 2015, 137, 5549), we demonstrated the generation of hot electrons in Mn-doped II-VI semiconductor quantum dots and their usefulness in photocatalytic H2 production reaction, taking advantage of the more efficient charge transfer of hot electrons compared with band-edge electrons. Here, we show that hot electrons produced in Mn-doped CdS/ZnS quantum dots possess sufficient kinetic energy to overcome the energy barrier from a 5.4-7.5 nm thick Al2 O3 layer producing a hot-electron current in photoelectrochemical cell. This work demonstrates the possibility of harvesting hot electrons not only at the interface of the doped quantum dot surface, but also far away from it, thus taking advantage of the capability of hot electrons for long-range electron transfer across a thick energy barrier. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Studies of instabilities and waves in a mirror confined hot electron plasma

    International Nuclear Information System (INIS)

    Huang Chaosong; Qiu Lijian; Ren Zhaoxing

    1989-01-01

    The stability of hot electron plasmas is studied. The hot electron component can stabilize the low frequency drift wave and the interchange mode driven by the plasma, which depends only on α=N h /N i , the density ratio of the hot electrons to the plasma ions, but not on the beta value and the annular structure of the hot electrons. Stabilization of the drift wave occurs for α > 40%, and that of the interchange mode for α > 5%, which allows the prediction that the interchange mode can be suppressed in hot electron plasma experiments. The experiments have been conducted in a simple mirror machine. It is observed that the plasma drives a drift wave at 40 kHz and an interchange mode at about 100 kHz. The fluctuation amplitude of the drift wave is much higher than that of the interchange mode. The hot electrons reduce the density gradient, the fluctuation amplitude and the radial loss of the plasma. On the other hand, the hot electrons drive the interchange mode and drift wave in the ion cyclotron frequency region. The effects of a cold plasma on hot electron perturbations are discussed. (author). 10 refs, 6 figs

  16. Hot electron attenuation of direct and scattered carriers across an epitaxial Schottky interface

    NARCIS (Netherlands)

    Parui, S.; Klandermans, P. S.; Venkatesan, S.; Scheu, C.; Banerjee, T.

    2013-01-01

    Hot electron transport of direct and scattered carriers across an epitaxial NiSi2/n-Si(111) interface, for different NiSi2 thickness, is studied using ballistic electron emission microscopy (BEEM). We find the BEEM transmission for the scattered hot electrons in NiSi2 to be significantly lower than

  17. Profile modification and hot electron temperature from resonant absorption at modest intensity

    International Nuclear Information System (INIS)

    Albritton, J.R.; Langdon, A.B.

    1980-01-01

    Resonant absorption is investigated in expanding plasmas. The momentum deposition associated with the ejection of hot electrons toward low density via wavebreaking readily exceeds that of the incident laser radiation and results in significant modification of the density profile at critical. New scaling of hot electron temperature with laser and plasma parameters is presented

  18. The effect of hot electrons and surface plasmons on heterogeneous catalysis

    International Nuclear Information System (INIS)

    Kim, Sun Mi; Lee, Si Woo; Moon, Song Yi; Park, Jeong Young

    2016-01-01

    Hot electrons and surface-plasmon-driven chemistry are amongst the most actively studied research subjects because they are deeply associated with energy dissipation and the conversion processes at the surface and interfaces, which are still open questions and key issues in the surface science community. In this topical review, we give an overview of the concept of hot electrons or surface-plasmon-mediated hot electrons generated under various structural schemes (i.e. metals, metal–semiconductor, and metal–insulator–metal) and their role affecting catalytic activity in chemical reactions. We highlight recent studies on the relation between hot electrons and catalytic activity on metallic surfaces. We discuss possible mechanisms for how hot electrons participate in chemical reactions. We also introduce controlled chemistry to describe specific pathways for selectivity control in catalysis on metal nanoparticles. (topical review)

  19. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  20. On the accuracy of current TCAD hot carrier injection models in nanoscale devices

    Science.gov (United States)

    Zaka, Alban; Rafhay, Quentin; Iellina, Matteo; Palestri, Pierpaolo; Clerc, Raphaël; Rideau, Denis; Garetto, Davide; Dornel, Erwan; Singer, Julien; Pananakakis, Georges; Tavernier, Clément; Jaouen, Hervé

    2010-12-01

    In this work, the hot electron injection models presently available for technology support have been investigated within the context of the development of advanced embedded non-volatile memories. The distribution functions obtained by these models (namely the Fiegna Model - FM [1], the Lucky Electron Model - LEM [2] and the recently implemented Spherical Harmonics Expansion of the Boltzman's Transport Equation - SHE [3]), have been systematically compared to rigorous Monte Carlo (MC) results [4], both in homogeneous and device conditions. Gate-to-drain current ratio and gate current density simulation has also been benchmarked in device simulations. Results indicate that local models such as FM, can partially capture the channel hot electron injection, at the price of model parameter adjustments. Moreover, at least in the device and field condition considered in this work, an overall better agreement with MC simulations has been obtained using the 1st order SHE, even without any particular fitting procedure. Extending the results presented in [3] by exploring shorter gate lengths and addressing the floating gate voltage dependence of the gate current, this work shows that the SHE method could contribute to bridge the gap between the rigorous but time consuming MC method and less rigorous but suitable TCAD local models.

  1. A Hot-electron Direct Detector for Radioastronomy

    Science.gov (United States)

    Karasik, B. S.; McGrath, W. R.; LeDuc, H. G.

    2000-01-01

    A new approach is proposed to improve the sensitivity of direct-detection bolometers. The idea is to adjust a speed of the thermal relaxation of hot-electrons in a nanometer size normal metal or superconductive transition edge bolometer by controlling the elastic electron mean free path. If the bolometer contacts are made of a superconductor with high critical temperature then the thermal diffusion into the contacts is absent because of the Andreev's reflection and the electron-phonon relaxation is the only mechanism for heat removal. The relaxation rate should behave as 7(exp 4)l at subkelvin temperatures (l is the electron elastic mean free path) and can be reduced by factor of 10 - 100 by decreasing l. Then an antenna- or waveguide-coupled bolometer with a time constant approx. 10(exp -3) to 10(exp -5) S at T approx. = 0.1 - 0.3 K will exhibit photon-noise limited performance in millimeter and subn-millimeter range. The bolometer will have a figure-of-merit NEk square root of tau approx. = 10(exp -22) 10(exp -21) W/Hz at 100 mK which is 10(exp 3) times smaller than that of a state-of-the-art bolometer. This will allow for a tremendous increase in speed which will have a significant impact for observational mapping applications. Alternatively, the bolometer could operate at higher temperature with still superior sensitivity This research was performed by the Center for Space Microelectronics Technology, JPL, California Institute of Technology, under the contract for NASA.

  2. Electrically excited hot-electron dominated fluorescent emitters using individual Ga-doped ZnO microwires via metal quasiparticle film decoration.

    Science.gov (United States)

    Liu, Yang; Jiang, Mingming; Zhang, Zhenzhong; Li, Binghui; Zhao, Haifeng; Shan, Chongxin; Shen, Dezhen

    2018-03-28

    The generation of hot electrons from metal nanostructures through plasmon decay provided a direct interfacial charge transfer mechanism, which no longer suffers from the barrier height restrictions observed for metal/semiconductor interfaces. Metal plasmon-mediated energy conversion with higher efficiency has been proposed as a promising alternative to construct novel optoelectronic devices, such as photodetectors, photovoltaic and photocatalytic devices, etc. However, the realization of the electrically-driven generation of hot electrons, and the application in light-emitting devices remain big challenges. Here, hybrid architectures comprising individual Ga-doped ZnO (ZnO:Ga) microwires via metal quasiparticle film decoration were fabricated. The hottest spots could be formed towards the center of the wires, and the quasiparticle films were converted into physically isolated nanoparticles by applying a bias onto the wires. Thus, the hot electrons became spatially localized towards the hottest regions, leading to a release of energy in the form of emitting photons. By adjusting the sputtering times and appropriate alloys, such as Au and Ag, wavelength-tunable emissions could be achieved. To exploit the EL emission characteristics, metal plasmons could be used as active elements to mediate the generation of hot electrons from metal nanostructures, which are located in the light-emitting regions, followed by injection into ZnO:Ga microwire-channels; thus, the production of plasmon decay-induced hot-electrons could function as an efficient approach to dominate emission wavelengths. Therefore, by introducing metal nanostructure decoration, individual ZnO:Ga microwires can be used to construct wavelength-tunable fluorescent emitters. The hybrid architectures of metal-ZnO micro/nanostructures offer a fantastic candidate to broaden the potential applications of semiconducting optoelectronic devices, such as photovoltaic devices, photodetectors, optoelectronic sensors, etc.

  3. Anisotropy effects on curvature-driven flute instabilities in a hot-electron plasma

    International Nuclear Information System (INIS)

    Spong, D.A.; Berk, H.L.; Van Dam, J.W.; Rosenbluth, M.N.

    1982-08-01

    The effects of finite parallel temperature are investigated for a hot electron plasma with sufficiently large beta that the magnetic field scale length (Δ/sub B/) is small compared with the vacuum field radius of curvature (R). Numerical and analytical estimates of stability boundaries are obtained for the four possible modes that can be treated in this limit: the conventional hot electron interchange, the high frequency hot electron interchange (ω > ω/sub ci/), the compressional Alfven mode, and the interacting pressure-driven interchange

  4. Production of hot electrons in mirror systems associated with ECR heating with longitudinal input of microwaves

    International Nuclear Information System (INIS)

    Zhil'tsov, V.A.; Skovoroda, A.A.; Timofeev, A.V.; Kharitonov, K.Yu.; Shcherbakov, A.G.

    1991-01-01

    Almost all experiments on ECR plasma heating are accompanied by the formation of hot electrons (i.e., electrons with energy substantially greater than the average of the bulk population). In mirror systems these electrons may determine the basic energy content (β) of the plasma. In this paper, results are presented from experimental measurements of the hot electron population resulting from ECR heating of the plasma in OGRA-4. A theoretical model is developed which describes the hot electron dynamics and the propagation of electromagnetic oscillations in the plasma self-consistently. The results obtained with this model are in agreement with experimental data

  5. Curvature-driven instabilities in a hot-electron plasma: radial analysis

    International Nuclear Information System (INIS)

    Berk, H.L.; Van Dam, J.W.; Rosenbluth, M.N.; Spong, D.A.

    1981-12-01

    The theory of unfavorable curvature-driven instabilities is developed for a plasma interacting with a hot electron ring whose drift frequencies are larger than the growth rates predicted from conventional magnetohydrodynamic theory. A z-pinch model is used to emphasize the radial structure of the problem. Stability criteria are obtained for the five possible modes of instability: the conventional hot electron interchange, a high-frequency hot electron interchange (at frequencies larger than the ion cyclotron frequency), a compressional instability, a background pressure-driven interchange, and an interacting pressure-driven interchange

  6. Resonant plasmonic terahertz detection in vertical graphene-base hot-electron transistors

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhii, V. [Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Center for Photonics and Infrared Engineering, Bauman Moscow State Technical University and Institute of Ultra High Frequency Semiconductor Electronics of RAS, Moscow 111005 (Russian Federation); Otsuji, T. [Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Ryzhii, M. [Department of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu 965-8580 (Japan); Mitin, V. [Department of Electrical Engineering, University at Buffalo, SUNY, Buffalo, New York 1460-1920 (United States); Shur, M. S. [Department of Electrical, Computer, and System Engineering and Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2015-11-28

    We analyze dynamic properties of vertical graphene-base hot-electron transistors (GB-HETs) and consider their operation as detectors of terahertz (THz) radiation using the developed device model. The GB-HET model accounts for the tunneling electron injection from the emitter, electron propagation across the barrier layers with the partial capture into the GB, and the self-consistent oscillations of the electric potential and the hole density in the GB (plasma oscillations), as well as the quantum capacitance and the electron transit-time effects. Using the proposed device model, we calculate the responsivity of GB-HETs operating as THz detectors as a function of the signal frequency, applied bias voltages, and the structural parameters. The inclusion of the plasmonic effect leads to the possibility of the GB-HET operation at the frequencies significantly exceeding those limited by the characteristic RC-time. It is found that the responsivity of GB-HETs with a sufficiently perfect GB exhibits sharp resonant maxima in the THz range of frequencies associated with the excitation of plasma oscillations. The positions of these maxima are controlled by the applied bias voltages. The GB-HETs can compete with and even surpass other plasmonic THz detectors.

  7. Superconducting Hot-Electron Submillimeter-Wave Detector

    Science.gov (United States)

    Karasik, Boris; McGrath, William; Leduc, Henry

    2009-01-01

    A superconducting hot-electron bolometer has been built and tested as a prototype of high-sensitivity, rapid-response detectors of submillimeter-wavelength radiation. There are diverse potential applications for such detectors, a few examples being submillimeter spectroscopy for scientific research; detection of leaking gases; detection of explosive, chemical, and biological weapons; and medical imaging. This detector is a superconducting-transition- edge device. Like other such devices, it includes a superconducting bridge that has a low heat capacity and is maintained at a critical temperature (T(sub c)) at the lower end of its superconducting-transition temperature range. Incident photons cause transient increases in electron temperature through the superconducting-transition range, thereby yielding measurable increases in electrical resistance. In this case, T(sub c) = 6 K, which is approximately the upper limit of the operating-temperature range of silicon-based bolometers heretofore used routinely in many laboratories. However, whereas the response speed of a typical silicon- based laboratory bolometer is characterized by a frequency of the order of a kilohertz, the response speed of the present device is much higher characterized by a frequency of the order of 100 MHz. For this or any bolometer, a useful figure of merit that one seeks to minimize is (NEP)(tau exp 1/2), where NEP denotes the noise-equivalent power (NEP) and the response time. This figure of merit depends primarily on the heat capacity and, for a given heat capacity, is approximately invariant. As a consequence of this approximate invariance, in designing a device having a given heat capacity to be more sensitive (to have lower NEP), one must accept longer response time (slower response) or, conversely, in designing it to respond faster, one must accept lower sensitivity. Hence, further, in order to increase both the speed of response and the sensitivity, one must make the device very small in

  8. Importance of field-reversing ion ring formation in hot electron plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ikuta, K.

    1975-11-01

    Formation of the field reversing ion ring in the mirror confined hot electron plasma may offer a device to confine the fusion plasma even under the restriction of the present technology. (Author) (GRA)

  9. Fabrication of High-T(sub c) Hot-Electron Bolometric Mixers for Terahertz Applications

    Science.gov (United States)

    Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.; Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

    1996-01-01

    Superocnducting hot-electron bolometers (HEB) represent a promising candidate for heterodyne mixing at frequencies exceeding 1 THz. Nb HEB mixers offer performance competitive with tunnel junctions without the frequency limit imposed by the superconducting energy gap.

  10. Hot-electron surface retention in intense short-pulse laser-matter interactions.

    Science.gov (United States)

    Mason, R J; Dodd, E S; Albright, B J

    2005-07-01

    Implicit hybrid plasma simulations predict that a significant fraction of the energy deposited into hot electrons can be retained near the surface of targets with steep density gradients illuminated by intense short-pulse lasers. This retention derives from the lateral transport of heated electrons randomly emitted in the presence of spontaneous magnetic fields arising near the laser spot, from geometric effects associated with a small hot-electron source, and from E fields arising in reaction to the ponderomotive force. Below the laser spot hot electrons are axially focused into a target by the B fields, and can filament in moderate Z targets by resistive Weibel-like instability, if the effective background electron temperature remains sufficiently low. Carefully engineered use of such retention in conjunction with ponderomotive density profile steepening could result in a reduced hot-electron range that aids fast ignition. Alternatively, such retention may disturb a deeper deposition needed for efficient radiography and backside fast ion generation.

  11. Efficient, Broadband and Wide-Angle Hot-Electron Transduction using Metal-Semiconductor Hyperbolic Metamaterials

    KAUST Repository

    Sakhdari, Maryam; Hajizadegan, Mehdi; Farhat, Mohamed; Chen, Pai-Yen

    2016-01-01

    Hot-electron devices are emerging as promising candidates for the transduction of optical radiation into electrical current, as they enable photodetection and solar/infrared energy harvesting at sub-bandgap wavelengths. Nevertheless, poor

  12. Sheath formation of a plasma containing multiply charged ions, cold and hot electrons, and emitted electrons

    International Nuclear Information System (INIS)

    You, H.J.

    2012-01-01

    It is quite well known that ion confinement is an important factor in an electron cyclotron resonance ion source (ECRIS) as it is closely related to the plasma potential. A model of sheath formation was extended to a plasma containing multiply charged ions (MCIs), cold and hot electrons, and secondary electrons emitted either by MCIs or hot electrons. In the model, a modification of the 'Bohm criterion' was given, the sheath potential drop and the critical emission condition were also analyzed. It appears that the presence of hot electrons and emitted electrons strongly affects the sheath formation so that smaller hot electrons and larger emission current result in reduced sheath potential (or floating potential). However the sheath potential was found to become independent of the emission current J when J > J c , (where J c is the critical emission current. The paper is followed by the associated poster

  13. Amplification of hot electron flow by the surface plasmon effect on metal–insulator–metal nanodiodes

    International Nuclear Information System (INIS)

    Lee, Changhwan; Nedrygailov, Ievgen I; Keun Lee, Young; Lee, Hyosun; Young Park, Jeong; Ahn, Changui; Jeon, Seokwoo

    2015-01-01

    Au–TiO_2–Ti nanodiodes with a metal–insulator–metal structure were used to probe hot electron flows generated upon photon absorption. Hot electrons, generated when light is absorbed in the Au electrode of the nanodiode, can travel across the TiO_2, leading to a photocurrent. Here, we demonstrate amplification of the hot electron flow by (1) localized surface plasmon resonance on plasmonic nanostructures fabricated by annealing the Au–TiO_2–Ti nanodiodes, and (2) reducing the thickness of the TiO_2. We show a correlation between changes in the morphology of the Au electrodes caused by annealing and amplification of the photocurrent. Based on the exponential dependence of the photocurrent on TiO_2 thickness, the transport mechanism for the hot electrons across the nanodiodes is proposed. (paper)

  14. Modification of the Absorption Edge of GaAs Arising from Hot-Electron Effects

    DEFF Research Database (Denmark)

    McGroddy, J. C.; Christensen, Ove

    1973-01-01

    We have observed a large enhancement of the electric-field-induced optical absorption arising from hot-electron effects in n-type GaAs at 77 K. The magnitude and field dependence of the enhancement can be approximately accounted for by a theory attributing the effect to broadening of the final...... states of the optical transitions by interaction with the nonequilibrium optical phonons produced by the hot electrons....

  15. Radial structure of curvature-driven instabilities in a hot-electron plasma

    International Nuclear Information System (INIS)

    Spong, D.A.; Berk, H.L.; Van Dam, J.W.

    1984-01-01

    A nonlocal analysis of curvature-driven instabilities for a hot-electron ring interacting with a warm background plasma has been made. Four different instability modes characteristic of hot-electron plasmas have been examined: the high-frequency hot-electron interchange (at frequencies larger than the ion-cyclotron frequency), the compressional Alfven instability, the interacting background pressure-driven interchange, and the conventional hot-electron interchange (at frequencies below the ion-cyclotron frequency). The decoupling condition between core and hot-electron plasmas has also been examined, and its influence on the background and hot-electron interchange stability boundaries has been studied. The assumed equilibrium plasma profiles and resulting radial mode structure differ somewhat from those used in previous local analytic estimates; however, when the analysis is calibrated to the appropriate effective radial wavelength of the nonlocal calculation, reasonable agreement is obtained. Comparison with recent experimental measurements indicates that certain of these modes may play a role in establishing operating boundaries for the ELMO Bumpy Torus-Scale (EBT-S) experiment. The calculations given here indicate the necessity of having core plasma outside the ring to prevent the destabilizing wave resonance of the precessional mode with a cold plasma

  16. Dual-mode operation of 2D material-base hot electron transistors

    KAUST Repository

    Lan, Yann-Wen; Jr., Carlos M. Torres,; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R.; Lerner, Mitchell B.; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L.

    2016-01-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  17. Dual-mode operation of 2D material-base hot electron transistors

    KAUST Repository

    Lan, Yann-Wen

    2016-09-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  18. Pluto's Nonvolatile Chemical Compounds

    Science.gov (United States)

    Grundy, William M.; Binzel, Richard; Cook, Jason C.; Cruikshank, Dale P.; Dalle Ore, Cristina M.; Earle, Alissa M.; Ennico, Kimberly; Jennings, Donald; Howett, Carly; Kaiser, Ralf-Ingo; Linscott, Ivan; Lunsford, A. W.; Olkin, Catherine B.; Parker, Alex Harrison; Parker, Joel Wm.; Philippe, Sylvain; Protopapa, Silvia; Quirico, Eric; Reuter, D. C.; Schmitt, Bernard; Singer, Kelsi N.; Spencer, John R.; Stansberry, John A.; Stern, S. Alan; Tsang, Constantine; Verbiscer, Anne J.; Weaver, Harold A.; Weigle, G. E.; Young, Leslie

    2016-10-01

    Despite the migration of Pluto's volatile ices (N2, CO, and CH4) around the surface on seasonal timescales, the planet's non-volatile materials are not completely hidden from view. They occur in a variety of provinces formed over a wide range of timescales, including rugged mountains and chasms, the floors of mid-latitude craters, and an equatorial belt of especially dark and reddish material typified by the informally named Cthulhu Regio. NASA's New Horizons probe observed several of these regions at spatial resolutions as fine as 3 km/pixel with its LEISA imaging spectrometer, covering wavelengths from 1.25 to 2.5 microns. Various compounds that are much lighter than the tholin-like macromolecules responsible for the reddish coloration, but that are not volatile at Pluto surface temperatures such as methanol (CH3OH) and ethane (C2H6) have characteristic absorption bands within LEISA's wavelength range. This presentation will describe their geographic distributions and attempt to constrain their origins. Possibilities include an inheritance from Pluto's primordial composition (the likely source of H2O ice seen on Pluto's surface) or ongoing production from volatile precursors through photochemistry in Pluto's atmosphere or through radiolysis on Pluto's surface. New laboratory data inform the analysis.This work was supported by NASA's New Horizons project.

  19. Hot-electron-based solar energy conversion with metal-semiconductor nanodiodes

    Science.gov (United States)

    Lee, Young Keun; Lee, Hyosun; Lee, Changhwan; Hwang, Euyheon; Park, Jeong Young

    2016-06-01

    Energy dissipation at metal surfaces or interfaces between a metal and a dielectric generally results from elementary excitations, including phonons and electronic excitation, once external energy is deposited to the surface/interface during exothermic chemical processes or an electromagnetic wave incident. In this paper, we outline recent research activities to develop energy conversion devices based on hot electrons. We found that photon energy can be directly converted to hot electrons and that hot electrons flow through the interface of metal-semiconductor nanodiodes where a Schottky barrier is formed and the energy barrier is much lower than the work function of the metal. The detection of hot electron flow can be successfully measured using the photocurrent; we measured the photoyield of photoemission with incident photons-to-current conversion efficiency (IPCE). We also show that surface plasmons (i.e. the collective oscillation of conduction band electrons induced by interaction with an electromagnetic field) are excited on a rough metal surface and subsequently decay into secondary electrons, which gives rise to enhancement of the IPCE. Furthermore, the unique optical behavior of surface plasmons can be coupled with dye molecules, suggesting the possibility for producing additional channels for hot electron generation.

  20. Hot electron formation in thermal barrier region of tandem mirror GAMMA 10

    International Nuclear Information System (INIS)

    Katanuma, I.; Kiwamoto, Y.; Sawada, K.; Miyoshi, S.

    1987-01-01

    We have studied the hot electron build-up by the second harmonic electron cyclotron resonance heating in the thermal barrier region of tandem mirror GAMMA 10 by using a Fokker-Planck code with self-consistent potential profile taken into account. We have found two phases in the evolution of hot electron population and the potential profile. In the first phase where the RF diffusion is dominant quick increase of the hot electron density and that of the mean energy are observed. No further increase in the mean energy is observed thereafter. The potential is the deepest during the first phase. The second phase starts in the mean-free-time of the pitch angle scattering of hot electrons on cold electrons and ions. In this phase the hot electron population increases in the rate of the pitch angle scattering. The potential dip shallows due to the accumulation of pitch angle scattered passing ions. This observation indicates the necessity of the ion pumping for maintaining the negative potential at the thermal barrier. (author)

  1. Effects of magnetic configuration on hot electrons in highly charged ECR plasma

    International Nuclear Information System (INIS)

    Zhao, H Y; Zhao, H W; Sun, L T; Wang, H; Ma, B H; Zhang, X Zh; Li, X X; Ma, X W; Zhu, Y H; Lu, W; Shang, Y; Xie, D Z

    2009-01-01

    To investigate the hot electrons in highly charged electron cyclotron resonance (ECR) plasma, Bremsstrahlung radiations were measured on two ECR ion sources at the Institute of Modern Physics. Used as a comparative index of the mean energy of the hot electrons, a spectral temperature, T spe , is derived through a linear fitting of the spectra in a semi-logarithmic representation. The influences of the external source parameters, especially the magnetic configuration, on the hot electrons are studied systematically. This study has experimentally demonstrated the importance of high microwave frequency and high magnetic field in the electron resonance heating to produce a high density of hot electrons, which is consistent with the empirical ECR scaling laws. The experimental results have again shown that a good compromise is needed between the ion extraction and the plasma confinement for an efficient production of highly charged ion beams. In addition, this investigation has shown that the correlation between the mean energy of the hot electrons and the magnetic field gradient at the ECR is well in agreement with the theoretical models.

  2. Dual-mode operation of 2D material-base hot electron transistors.

    Science.gov (United States)

    Lan, Yann-Wen; Torres, Carlos M; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R; Lerner, Mitchell B; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L

    2016-09-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  3. Hot Electron Effects of Importance for Micron and Submicron Devices.

    Science.gov (United States)

    1981-09-01

    excited near the edge of its Indexing terms: Opticalfibres, Ware propagation core and along one of its principal axes. Fig. 2 is produced by a Short (1-400...Recently the nature of ray propagation in ellipti- cal fibres has been investigated by several authors.’ - In parti- cular. Ankiew~cz has plotted...pair injected into the active region. That g(E) tron energy loss (in units of LO phonons do modify laser action has been shown in the 4 ,) stevia

  4. Perpendicular electron cyclotron emission from hot electrons in TMX-U

    International Nuclear Information System (INIS)

    James, R.A.; Ellis, R.F.; Lasnier, C.J.; Casper, T.A.; Celata, C.M.

    1984-01-01

    Perpendicular electron cyclotron emission (PECE) from the electron cyclotron resonant heating of hot electrons in TMX-U is measured at 30 to 40 and 50 to 75 GHz. This emission is optically thin and is measured at the midplane, f/sub ce/ approx. = 14 GHz, in either end cell. In the west end cell, the emission can be measured at different axial positions thus yielding the temporal history of the hot electron axial profile. These profiles are in excellent agreement with the axial diamagnetic signals. In addition, the PECE signal level correlates well with the diamagnetic signal over a wide range of hot electron densities. Preliminary results from theoretical modeling and comparisons with other diagnostics are also presented

  5. The optimization of production and control of hot-electron plasmas

    International Nuclear Information System (INIS)

    1989-01-01

    The present project was initially undertaken to develop a number of innovative concepts for using electron cyclotron heating (ECH) to enhance tokamak performance. A common feature of the various applications under consideration is efficient, spatially-localized generation of hot-electron plasmas; and the first phase of the work addressed the basic aspects of an approach to achieving this Upper Off-Resonant Heating (UORH) and open-resonator couplers to confine the weakly damped microwave power to the particular region where the hot electrons are to be generated. The results of the first year's work provided strong evidence that hot-electron plasmas with electron energies of hundreds of keV could be generated using multiple-frequency ECH and fully-toroidal open-resonator couplers. The evidence was sufficiently compelling to suggest that the project be focused on a suitable near-term application to the TEXT device

  6. Spin dependent transport of hot electrons through ultrathin epitaxial metallic films

    Energy Technology Data Exchange (ETDEWEB)

    Heindl, Emanuel

    2010-06-23

    In this work relaxation and transport of hot electrons in thin single crystalline metallic films is investigated by Ballistic Electron Emission Microscopy. The electron mean free paths are determined in an energy interval of 1 to 2 eV above the Fermi level. While fcc Au-films appear to be quite transmissive for hot electrons, the scattering lengths are much shorter for the ferromagnetic alloy FeCo revealing, furthermore, a strong spin asymmetry in hot electron transport. Additional information is gained from temperature dependent studies in combination with golden rule approaches in order to disentangle the impact of several relaxation and transport properties. It is found that bcc Fe-films are much less effective in spin filtering than films made of the FeCo-alloy. (orig.)

  7. Imaging Plasmon Hybridization of Fano Resonances via Hot-Electron-Mediated Absorption Mapping.

    Science.gov (United States)

    Simoncelli, Sabrina; Li, Yi; Cortés, Emiliano; Maier, Stefan A

    2018-05-04

    The inhibition of radiative losses in dark plasmon modes allows storing electromagnetic energy more efficiently than in far-field excitable bright-plasmon modes. As such, processes benefiting from the enhanced absorption of light in plasmonic materials could also take profit of dark plasmon modes to boost and control nanoscale energy collection, storage, and transfer. We experimentally probe this process by imaging with nanoscale precision the hot-electron driven desorption of thiolated molecules from the surface of gold Fano nanostructures, investigating the effect of wavelength and polarization of the incident light. Spatially resolved absorption maps allow us to show the contribution of each element of the nanoantenna in the hot-electron driven process and their interplay in exciting a dark plasmon mode. Plasmon-mode engineering allows control of nanoscale reactivity and offers a route to further enhance and manipulate hot-electron driven chemical reactions and energy-conversion and transfer at the nanoscale.

  8. Efficient, Broadband and Wide-Angle Hot-Electron Transduction using Metal-Semiconductor Hyperbolic Metamaterials

    KAUST Repository

    Sakhdari, Maryam

    2016-05-20

    Hot-electron devices are emerging as promising candidates for the transduction of optical radiation into electrical current, as they enable photodetection and solar/infrared energy harvesting at sub-bandgap wavelengths. Nevertheless, poor photoconversion quantum yields and low bandwidth pose fundamental challenge to fascinating applications of hot-electron optoelectronics. Based on a novel hyperbolic metamaterial (HMM) structure, we theoretically propose a vertically-integrated hot-electron device that can efficiently couple plasmonic excitations into electron flows, with an external quantum efficiency approaching the physical limit. Further, this metamaterial-based device can have a broadband and omnidirectional response at infrared and visible wavelengths. We believe that these findings may shed some light on designing practical devices for energy-efficient photodetection and energy harvesting beyond the bandgap spectral limit.

  9. Coaxial Ag/ZnO/Ag nanowire for highly sensitive hot-electron photodetection

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Yaohui; Li, Xiaofeng, E-mail: xfli@suda.edu.cn; Wu, Kai; Wu, Shaolong; Deng, Jiajia [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006 (China)

    2015-02-23

    Single-nanowire photodetectors (SNPDs) are mostly propelled by p-n junctions, where the detection wavelength is constrained by the band-gap width. Here, we present a simple doping-free metal/semiconductor/metal SNPD, which shows strong detection tunability without such a material constraint. The proposed hot-electron SNPD exhibits superior optical and electrical advantages, i.e., optically the coaxial design leads to a strong asymmetrical photoabsorption and results in a high unidirectional photocurrent, as desired by the hot-electron collection; electrically the hot-electrons are generated in the region very close to the barrier, facilitating the electrical transport. Rigorous calculations predict an unbiased photoresponsivity of ∼200 nA/mW.

  10. Hot electron plasma equilibrium and stability in the Constance B mirror experiment

    International Nuclear Information System (INIS)

    Chen, Xing.

    1988-04-01

    An experimental study of the equilibrium and macroscopic stability property of an electron cyclotron resonance heating (ECRH) generated plasma in a minimum-B mirror is presented. The Constance B mirror is a single cell quadrupole magnetic mirror in which high beta (β ≤ 0.3) hot electron plasmas (T/sub e/≅400 keV) are created with up to 4 kW of ECRH power. The plasma equilibrium profile is hollow and resembles the baseball seam geometry of the magnet which provides the confining magnetic field. This configuration coincides with the drift orbit of deeply trapped particles. The on-axis hollowness of the hot electron density profile is 50 /+-/ 10%, and the pressure profile is at least as hollow as, if not more than, the hot electron density profile. The hollow plasma equilibrium is macroscopically stable and generated in all the experimental conditions in which the machine has been operated. Small macroscopic plasma fluctuations in the range of the hot electron curvature drift frequency sometimes occur but their growth rate is small (ω/sub i//ω/sub r/ ≤ 10 -2 ) and saturate at very low level (δB//bar B/ ≤ 10 -3 ). Particle drift reversal is predicted to occur for the model pressure profile which best fits the experimental data under the typical operating conditions. No strong instability is observed when the plasma is near the drift reversal parameter regime, despite a theoretical prediction of instability under such conditions. The experiment shows that the cold electron population has no stabilizing effect to the hot electrons, which disagrees with current hot electron stability theories and results of previous maximum-B experiments. A theoretical analysis using MHD theory shows that the compressibility can stabilize a plasma with a hollowness of 20--30% in the Constance B mirror well. 57 refs

  11. Characteristics of hot electron ring in a simple magnetic mirror field

    International Nuclear Information System (INIS)

    Hosokawa, M.; Ikegami, H.

    1980-12-01

    Characteristics of hot electron ring are studied in a simple magnetic mirror machine (mirror ratio 2 : 1) with a diameter of 30 cm at the midplane and with the distance of 80 cm between the mirrors. Maximum microwave input power is 5 kW at 6.4 GHz with the corresponding power density of approximately 0.3 W/cm 3 . With a background cold plasma of 4 x 10 11 cm -3 , hot electron rings are most effectively generated in two cases when the magnetic field on the axis of the midplane is set near the fundamental or the second harmonic electron cyclotron resonance to the applied microwave frequency. Density profile of the hot electrons is observed to take a so-called ring shape with a radius controllable by the magnetic field intensity and with an axial length of approximately 10 cm. The radial cut view of the ring, however, indicates an M shape density profile, and the density of the hot electrons on the axis is about one half of the density at the ring. Approximately 30 msec is needed before generating the hot electron ring at the density of 10 10 cm -3 with an average kinetic energy of 100 keV. The ultimate energy distribution function is observed to have a stepwise cut in the high energy tail and no energetic components above 1 MeV are detected. The hot electron ring is susceptible to a few instabilities which can be artificially triggered. One of the instabilities is observed to associate with a loss of lower energetic electrons and microwave bursts. At the instability, the ring shape is observed to transform into a filled cylinder in a few microseconds and disappear. (author)

  12. Hot electron effects on the satellite spectrum of laser-produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, J. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM (United States); Faenov, A.Y.; Pikuz, T.A. [MISDC, NPO ' VNIIFTRI' , Mendeleevo, Moscow Region, 141570 (Russian Federation); Wilke, M.D.; Kyrala, G.A.; Clark, R.E.H. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM (United States)

    1999-05-01

    In laser-produced plasmas, the interaction of the intense laser light with plasma electrons can produce high-energy superthermal electrons with energies in the keV range. These hot electrons can influence the level populations which determine spectral line structure. In the present paper, the effect of hot electrons on the X-ray satellite spectrum of laser-produced plasmas is studied. Calculated spectra are compared with experimental observations. Magnesium targets irradiated by three different types of laser pulses are considered. These include, a high-intensity 600 fs Nd-glass laser, a 1 ns Nd-glass laser, and a 2ns CO{sub 2} laser. The Nd-glass laser experiments were conducted recently at the Los Alamos Trident Facility and the CO{sub 2} data were recorded by MISDC. High-resolution spectra were measured near the He-like resonance line of magnesium. The calculations employ an electron energy distribution which includes a thermal and a hot electron component, as part of a detailed collisional-radiative model. Plasma parameters including electron temperature, density, and hot electron fraction are estimated by choosing best fits to the experimental measurements. The calculations show that hot electrons can cause several anomalous effects. The Li-like jkl, abcd, and qr satellites can show intensities which are generally attributed to electron densities in excess of 10{sup 23} cm{sup -3}. In addition, the relative amplitude of the intercombination line can be unusually large even at high electron densities due to enhanced collisional excitation of the 1s2p{sup 3}P state by hot electrons. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  13. Hot-electron-plasma accumulation in the CIRCE mirror experiment

    International Nuclear Information System (INIS)

    Bardet, R.; Briand, P.; Dupas, L.; Gormezano, C.; Melin, G.

    1975-01-01

    In the CIRCE experiment, the plasma is obtained by the trapping of a plasma injected into a magnetic bottle by electron heating at cyclotron resonance. The plasma density lies between 5x10 11 cm -3 and 10 12 cm -3 , the electron temperature is about 100 keV and the ion temperature is in the range of few hundred electronvolts. Gross instabilities are not observed. The ratio of the plasma density to the neutral-gas density inside the plasma is higher than 100. A few kilowatts of r.f. power at 8 GHz are sufficient to obtain these results, a fact which looks encouraging as far as the creation of a more effective fast-neutral-target plasma using the CIRCE-experiment concept is concerned. (author)

  14. Suppression of sawtooth oscillations due to hot electrons and hot ions

    International Nuclear Information System (INIS)

    Zhang, Y.Z.; Berk, H.L.

    1989-01-01

    The theory of m = 1 kink mode stabilization is discussed in the presence of either magnetically trapped hot electrons or hot ions. For instability hot ion requires particles peaked inside the q = 1 surface, while hot electrons require that its pressure profile be increasing at the q = 1 surface. Experimentally observed sawtooth stabilization usually occurs with off-axis heating with ECRH and near axis heating with ICRH. Such heating may produce the magnetically trapped hot particle pressure profiles that are consistent with theory. 17 refs., 2 figs

  15. Origin of Power Laws for Reactions at Metal Surfaces Mediated by Hot Electrons

    DEFF Research Database (Denmark)

    Olsen, Thomas; Schiøtz, Jakob

    2009-01-01

    A wide range of experiments have established that certain chemical reactions at metal surfaces can be driven by multiple hot-electron-mediated excitations of adsorbates. A high transient density of hot electrons is obtained by means of femtosecond laser pulses and a characteristic feature of such...... density functional theory and the delta self-consistent field method. With a simplifying assumption, the power law becomes exact and we obtain a simple physical interpretation of the exponent n, which represents the number of adsorbate vibrational states participating in the reaction....

  16. Proton beam shaped by “particle lens” formed by laser-driven hot electrons

    International Nuclear Information System (INIS)

    Zhai, S. H.; Shen, B. F.; Wang, W. P.; Zhang, H.; Zhang, L. G.; Huang, S.; Xu, Z. Z.; He, S. K.; Lu, F.; Zhang, F. Q.; Deng, Z. G.; Dong, K. G.; Wang, S. Y.; Zhou, K. N.; Xie, N.; Wang, X. D.; Liu, H. J.; Zhao, Z. Q.; Gu, Y. Q.; Zhang, B. H.

    2016-01-01

    Two-dimensional tailoring of a proton beam is realized by a “particle lens” in our experiment. A large quantity of electrons, generated by an intense femtosecond laser irradiating a polymer target, produces an electric field strong enough to change the trajectory and distribution of energetic protons flying through the electron area. The experiment shows that a strip pattern of the proton beam appears when hot electrons initially converge inside the plastic plate. Then the shape of the proton beam changes to a “fountain-like” pattern when these hot electrons diffuse after propagating a distance.

  17. Organic non-volatile memories from ferroelectric phase separated blends

    Science.gov (United States)

    Asadi, Kamal; de Leeuw, Dago; de Boer, Bert; Blom, Paul

    2009-03-01

    Ferroelectric polarisation is an attractive physical property for non-volatile binary switching. The functionality of the targeted memory should be based on resistive switching. Conductivity and ferroelectricity however cannot be tuned independently. The challenge is to develop a storage medium in which the favourable properties of ferroelectrics such as bistability and non-volatility can be combined with the beneficial properties provided by semiconductors such as conductivity and rectification. In this contribution we present an integrated solution by blending semiconducting and ferroelectric polymers into phase separated networks. The polarisation field of the ferroelectric modulates the injection barrier at the semiconductor--metal contact. This combination allows for solution-processed non-volatile memory arrays with a simple cross-bar architecture that can be read-out non-destructively. Based on this general concept a non-volatile, reversible switchable Schottky diode with relatively fast programming time of shorter than 100 microseconds, long information retention time of longer than 10^ days, and high programming cycle endurance with non-destructive read-out is demonstrated.

  18. Size dependence investigations of hot electron cooling dynamics in metal/adsorbates nanoparticles

    International Nuclear Information System (INIS)

    Bauer, Christophe; Abid, Jean-Pierre; Girault, Hubert H.

    2005-01-01

    The size dependence of electron-phonon coupling rate has been investigated by femtosecond transient absorption spectroscopy for gold nanoparticles (NPs) wrapped in a shell of sulfate with diameter varying from 1.7 to 9.2 nm. Broad-band spectroscopy gives an overview of the complex dynamics of nonequilibrium electrons and permits the choice of an appropriate probe wavelength for studying the electron-phonon coupling dynamics. Ultrafast experiments were performed in the weak perturbation regime (less than one photon in average per nanoparticle), which allows the direct extraction of the hot electron cooling rates in order to compare different NPs sizes under the same conditions. Spectroscopic data reveals a decrease of hot electron energy loss rates with metal/adsorbates nanosystem sizes. Electron-phonon coupling time constants obtained for 9.2 nm NPs are similar to gold bulk materials (∼1 ps) whereas an increase of hot electron cooling time up to 1.9 ps is observed for sizes of 1.7 nm. This is rationalized by the domination of surface effects over size (bulk) effects. The slow hot electron cooling is attributed to the adsorbates-induced long-lived nonthermal regime, which significantly reduces the electron-phonon coupling strength (average rate of phonon emission)

  19. Three-dimensional hot electron photovoltaic device with vertically aligned TiO2 nanotubes.

    Science.gov (United States)

    Goddeti, Kalyan C; Lee, Changhwan; Lee, Young Keun; Park, Jeong Young

    2018-05-09

    Titanium dioxide (TiO 2 ) nanotubes with vertically aligned array structures show substantial advantages in solar cells as an electron transport material that offers a large surface area where charges travel linearly along the nanotubes. Integrating this one-dimensional semiconductor material with plasmonic metals to create a three-dimensional plasmonic nanodiode can influence solar energy conversion by utilizing the generated hot electrons. Here, we devised plasmonic Au/TiO 2 and Ag/TiO 2 nanodiode architectures composed of TiO 2 nanotube arrays for enhanced photon absorption, and for the subsequent generation and capture of hot carriers. The photocurrents and incident photon to current conversion efficiencies (IPCE) were obtained as a function of photon energy for hot electron detection. We observed enhanced photocurrents and IPCE using the Ag/TiO 2 nanodiode. The strong plasmonic peaks of the Au and Ag from the IPCE clearly indicate an enhancement of the hot electron flux resulting from the presence of surface plasmons. The calculated electric fields and the corresponding absorbances of the nanodiode using finite-difference time-domain simulation methods are also in good agreement with the experimental results. These results show a unique strategy of combining a hot electron photovoltaic device with a three-dimensional architecture, which has the clear advantages of maximizing light absorption and a metal-semiconductor interface area.

  20. Analysis of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applications

    Science.gov (United States)

    Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

    1996-01-01

    The prospects of a YBa2Cu3O7(delta)(YBCO) hot-electron bolometer (HEB) mixer for a THz heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate.

  1. Hot-electron plasma formation and confinement in the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Ress, D.B.

    1988-01-01

    Electron-cyclotron range-of-frequency heating (ECRH) at 28 GHz is used to create a population of mirror-confined hot electrons in the Tandem Mirror Experiment-Upgrade (TMX-U). Generation of a large fraction of such electrons within each end-cell of TMX-U is essential to the formation of the desired electrostatic potential profile of the thermal-barrier tandem mirror. The formation and confinement of the ECRH-generated hot-electron plasma was investigated with a variety of diagnostic instruments, including a novel instrumented limiter probe. The author characterized the spatial structure of the hot-electron plasma. Details of the heating process cause the plasma to separate into two regions: a halo, consisting entirely of energetic electrons, and a core, which is dominated by cooler electrons. The plasma structure forms rapidly under the action of second-harmonic ECRH. Fundamental ECRH, which is typically applied simultaneously, is only weakly absorbed and generally does not create energetic electrons. The ECRH-generated plasma displays several loss mechanisms. Hot electrons in the halo region, with T e ∼ 30 keV, are formed by localized ECRH near the plasma boundary, and are lost through a radial process involving open magnetic-curvature-drift surfaces

  2. Study of Hot-Electron Effects, Breakdown and Reliability in FETS, HEMTS, and HBT’S

    Science.gov (United States)

    1998-08-01

    device (VDS = 7.5 V, VQS = -0.1 V, 137 hrs). (b) Drain Current FT-DLTS measurements in an as received device (open simbols ) and in a device after hot...electron stress test: VDS = 7.5 V, VQS = - 0.1 V, 137 hrs (closed simbols ). output characteristics of degraded devices and completely eliminates

  3. Generation and Beaming of Early Hot Electrons onto the Capsule in Laser-Driven Ignition Hohlraums

    Science.gov (United States)

    Dewald, E. L.; Hartemann, F.; Michel, P.; Milovich, J.; Hohenberger, M.; Pak, A.; Landen, O. L.; Divol, L.; Robey, H. F.; Hurricane, O. A.; Döppner, T.; Albert, F.; Bachmann, B.; Meezan, N. B.; MacKinnon, A. J.; Callahan, D.; Edwards, M. J.

    2016-02-01

    In hohlraums for inertial confinement fusion (ICF) implosions on the National Ignition Facility, suprathermal hot electrons, generated by laser plasma instabilities early in the laser pulse ("picket") while blowing down the laser entrance hole (LEH) windows, can preheat the capsule fuel. Hard x-ray imaging of a Bi capsule surrogate and of the hohlraum emissions, in conjunction with the measurement of time-resolved bremsstrahlung spectra, allows us to uncover for the first time the directionality of these hot electrons and infer the capsule preheat. Data and Monte Carlo calculations indicate that for most experiments the hot electrons are emitted nearly isotropically from the LEH. However, we have found cases where a significant fraction of the generated electrons are emitted in a collimated beam directly towards the capsule poles, where their local energy deposition is up to 10 × higher than the average preheat value and acceptable levels for ICF implosions. The observed "beaming" is consistent with a recently unveiled multibeam stimulated Raman scattering model [P. Michel et al., Phys. Rev. Lett. 115, 055003 (2015)], where laser beams in a cone drive a common plasma wave on axis. Finally, we demonstrate that we can control the amount of generated hot electrons by changing the laser pulse shape and hohlraum plasma.

  4. Localized structures of electromagnetic waves in hot electron-positron plasma

    International Nuclear Information System (INIS)

    Kartal, S.; Tsintsadze, L.N.; Berezhiani, V.I.

    1995-08-01

    The dynamics of relatively strong electromagnetic (EM) wave propagation in hot electron-positron plasma is investigated. The possibility of finding localized stationary structures of EM waves is explored. It it shown that under certain conditions the EM wave forms a stable localized soliton-like structures where plasma is completely expelled from the region of EM field location. (author). 9 refs, 2 figs

  5. Hot-electrons-induced ultrafast demagnitization in Co/Pt multilayers

    NARCIS (Netherlands)

    Bergeard, N.; Hehn, M.; Mangin, S.; Lengaigne, G.; Montaigne, F.; Lalieu, M. L. M.; Koopmans, B.; Malinowski, G.

    2016-01-01

    Using specially engineered structures to tailor the optical absorption in a metallic multilayer, we analyze the magnetization dynamics of a Co/Pt multilayer buried below a thick Cu layer. We demonstrate that hot electrons alone can very efficiently induce ultrafast demagnetization. Simulations based

  6. Penetration length-dependent hot electrons in the field emission from ZnO nanowires

    Science.gov (United States)

    Chen, Yicong; Song, Xiaomeng; Li, Zhibing; She, Juncong; Deng, Shaozhi; Xu, Ningsheng; Chen, Jun

    2018-01-01

    In the framework of field emission, whether or not hot electrons can form in the semiconductor emitters under a surface penetration field is of great concern, which will provide not only a comprehensive physical picture of field emission from semiconductor but also guidance on how to improve device performance. However, apart from some theoretical work, its experimental evidence has not been reported yet. In this article, the field penetration length-dependent hot electrons were observed in the field emission of ZnO nanowires through the in-situ study of its electrical and field emission characteristic before and after NH3 plasma treatment in an ultrahigh vacuum system. After the treatment, most of the nanowires have an increased carrier density but reduced field emission current. The raised carrier density was caused by the increased content of oxygen vacancies, while the degraded field emission current was attributed to the lower kinetic energy of hot electrons caused by the shorter penetration length. All of these results suggest that the field emission properties of ZnO nanowires can be optimized by modifying their carrier density to balance both the kinetic energy of field induced hot electrons and the limitation of saturated current under a given field.

  7. Model for ion confinement in a hot-electron tandem mirror anchor

    International Nuclear Information System (INIS)

    Baldwin, D.E.

    1980-01-01

    Anisotropic, hot electrons trapped in local minimum-B wells have been proposed as MHD-stabilizing anchors to an otherwise axisymmetric tandem configuration. This work describes a model for plasma confinement between the anchors and the remainder of the system and calcuates the power loss implied by maintenance of this plasma

  8. Specular Reflectivity and Hot-Electron Generation in High-Contrast Relativistic Laser-Plasma Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Gregory Elijah [The Ohio State Univ., Columbus, OH (United States)

    2013-01-01

    Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the cost of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic

  9. Experimental study on energy distribution of the hot electrons generated by femtosecond laser interacting with solid targets

    International Nuclear Information System (INIS)

    Gu Yuqiu; Zheng Zhijian; Zhou Weimin; Wen Tianshu; Chunyu Shutai; Cai Dafeng; Sichuan Univ., Chengdu; Neijiang Teachers College, Neijiang; Jiao Chunye; Chen Hao; Sichuan Univ., Chengdu; Yang Xiangdong

    2005-01-01

    This paper reports the results of the experiment of hot electron energy distribution during the femtosecond laser-solid target interaction. The hot electrons formed an anisotropic energy distribution. In the direction of the target normal, the energy spectrum of the hot electron was a Maxwellian-like distribution with an effective temperature of 206 keV, which was due to the resonance absorption. In the direction of the specular reflection of laser, there appeared a local plateau of hot electron energy spectrum at the beginning and then it was decreased gradually, which maybe produced by several acceleration mechanisms. The effective temperature and the yield of hot electrons in the direction of the target normal is larger than those in the direction of the specular reflection of laser, which proves that the resonance absorption mechanism is more effective than others. (authors)

  10. Transport effects with hot electrons in laser fusion. Final report, October 1, 1981-February 28, 1983

    International Nuclear Information System (INIS)

    Shkarofsky, I.P.

    1983-02-01

    Two explanations are offered which can account for heat inhibition found in laser-fusion experiments. The first explanation requires an anisotorpic electron velocity distribution with a higher temperature parallel to the surface than into the surface. This provides axial heat inhibition. Lateral heat inhibition is associated with azimuthal magnetic fields. The second explanation requires the presence of both hot suprathermal and thermal electrons. The hot electrons can cause the flux limiter to decrease substantially below the free-streaming limit in an intermediate range of collisionality. Conditions for this situation occur in the coronal region. We compare a Maxwellian distribution to an exp(-v 5 /v 5 /sub c/) variation for the cold electrons and find that the flux limiter decreases more for the latter case. The effects of collisions between cold and hot electrons is also looked into. The Cartesian tensor approach is used in the above investigations with various forms for the zeroth order electron velocity distribution function

  11. Gap-plasmon based broadband absorbers for enhanced hot-electron and photocurrent generation

    DEFF Research Database (Denmark)

    Lu, Yuhua; Dong, Wen; Chen, Zhuo

    2016-01-01

    Plasmonic hot-electron generation has recently come into focus as a new scheme for solar energy conversion. So far, however, due to the relatively narrow bandwidth of the surface plasmon resonances and the insufficient resonant light absorption, most of plasmonic photocatalysts show narrow......-band spectral responsivities and small solar energy conversion efficiencies. Here we experimentally demonstrate that a three-layered nanostructure, consisting of a monolayer gold-nanoparticles and a gold film separated by a TiO2 gap layer (Au-NPs/TiO2/Au-film), is capable of near-completely absorbing light...... within the whole visible region. We show that the Au-NPs/TiO2/Au-film device can take advantage of such strong and broadband light absorption to enhance the generation of hot electrons and thus the photocurrent under visible irradiation. As compared to conventional plasmonic photocatalysts such as Au...

  12. Hot Electron Photoemission from Plasmonic Nanostructures: The Role of Surface Photoemission and Transition Absorption

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Ikhsanov, Renat Sh

    2015-01-01

    We study mechanisms of photoemission of hot electrons from plasmonic nanoparticles. We analyze the contribution of "transition absorption", i.e., loss of energy of electrons passing through the boundary between different materials, to the surface mechanism of photoemission. We calculate photoemis......We study mechanisms of photoemission of hot electrons from plasmonic nanoparticles. We analyze the contribution of "transition absorption", i.e., loss of energy of electrons passing through the boundary between different materials, to the surface mechanism of photoemission. We calculate...... photoemission rate and transition absorption for nanoparticles surrounded by various media with a broad range of permittivities and show that photoemission rate and transition absorption follow the same dependence on the permittivity. Thus, we conclude that transition absorption is responsible...

  13. Hard x-ray measurements of the hot-electron rings in EBT-S

    International Nuclear Information System (INIS)

    Hillis, D.L.

    1982-06-01

    A thorough understanding of the hot electron rings in ELMO Bumpy Torus-Scale (EBT-S) is essential to the bumpy torus concept of plasma production, since the rings provide bulk plasma stability. The hot electrons are produced via electron cyclotron resonant heating using a 28-GHz cw gyrotron, which has operated up to power levels of 200 kW. The parameters of the energetic electron rings are studied via hard x-ray measurement techniques and with diamagnetic pickup coils. The hard x-ray measurements have used collimated NaI(Tl) detectors to determine the electron temperature T/sub e/ and electron density n/sub e/ for the hot electron annulus. Typical values of T/sub e/ are 400 to 500 keV and of n/sub e/ 2 to 5 x 10 11 cm -3 . The total stored energy of a single energetic electron ring as measured by diamagnetic pickup loops approaches approx. 40 J and is in good agreement with that deduced from hard x-ray measurements. By combining the experimental measurements from hard x-rays and the diamagnetic loops, an estimate can be obtained for the volume of a single hot electron ring. The ring volume is determined to be approx. 2.2 litres, and this volume remains approximately constant over the T-mode operating regime. Finally, the power in the electrons scattered out of the ring is measured indirectly by measuring the x-ray radiation produced when those electrons strike the chamber walls. The variation of this radiation with increasing microwave power levels is found to be consistent with classical scattering estimates

  14. How well do time-integrated Kα images represent hot electron spatial distributions?

    Science.gov (United States)

    Ovchinnikov, V. M.; Kemp, G. E.; Schumacher, D. W.; Freeman, R. R.; Van Woerkom, L. D.

    2011-07-01

    A computational study is described, which addresses how well spatially resolved time-integrated Kα images recorded in intense laser-plasma experiments correlate with the distribution of "hot" (>1 MeV) electrons as they propagate through the target. The hot electron angular distribution leaving the laser-plasma region is critically important for many applications such as Fast Ignition or laser based x-ray sources; and Kα images are commonly used as a diagnostic. It is found that Kα images can easily mislead due to refluxing and other effects. Using the particle-in-cell code LSP, it is shown that a Kα image is not solely determined by the initial population of forward directed hot electrons, but rather also depends upon "delayed" hot electrons, and in fact continues to evolve long after the end of the laser interaction. Of particular note, there is a population of hot electrons created during the laser-plasma interaction that acquire a velocity direction opposite that of the laser and subsequently reflux off the front surface of the target, deflect when they encounter magnetic fields in the laser-plasma region, and then traverse the target in a wide spatial distribution. These delayed fast electrons create significant features in the Kα time-integrated images. Electrons refluxing from the sides and the back of the target are also found to play a significant role in forming the final Kα image. The relative contribution of these processes is found to vary depending on depth within target. These effects make efforts to find simple correlations between Kα images and, for example, Fast Ignition relevant parameters prone to error. Suggestions for future target design are provided.

  15. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    Science, University ofMichigan, AnnArbor,MI 48109-2099, USA E-mail: czulick@umich.edu Keywords: laser- plasma ,mass-limited, fast electrons , sheath...New J. Phys. 18 (2016) 063020 doi:10.1088/1367-2630/18/6/063020 PAPER Target surface area effects on hot electron dynamics from high intensity laser... plasma interactions CZulick, ARaymond,AMcKelvey, VChvykov, AMaksimchuk, AGRThomas, LWillingale, VYanovsky andKKrushelnick Center forUltrafast Optical

  16. Limitation and suppression of hot electron fluctuations in submicron semiconductor structures

    International Nuclear Information System (INIS)

    Kochelap, V.A.; Zahleniuk, N.A.; Sokolov, V.N.

    1992-09-01

    We present theoretical investigations of fluctuations of hot electrons in submicron active regions, where the dimensions 2 d of the region is comparable to the electron energy relaxation length L ε . The new physical phenomenon is reported; the fluctuations depend on the sample thickness, with 2d ε a suppression of fluctuations arises in the range of fluctuation frequencies ω much less than T -1 ε , T ε is the electron energy relaxation time. (author). 12 refs, 7 figs

  17. Measurements of hot electrons in the Extrap T1 reversed-field pinch

    International Nuclear Information System (INIS)

    Welander, A.; Bergsaaker, H.

    1998-01-01

    The presence of an anisotropic energetic electron population in the edge region is a characteristic feature of reversed-field pinch (RFP) plasmas. In the Extrap T1 RFP, the anisotropic, parallel heat flux in the edge region measured by calorimetry was typically several hundred MWm -2 . To gain more insight into the origin of the hot electron component and to achieve time resolution of the hot electron flow during the discharge, a target probe with a soft x-ray monitor was designed, calibrated and implemented. The x-ray emission from the target was measured with a surface barrier detector covered with a set of different x-ray filters to achieve energy resolution. A calibration in the range 0.5-2 keV electron energy was performed on the same target and detector assembly using a LaB 6 cathode electron gun. The calibration data are interpolated and extrapolated numerically. A directional asymmetry of more than a factor of 100 for the higher energy electrons is observed. The hot electrons are estimated to constitute 10% of the total electron density at the edge and their energy distribution is approximated by a half-Maxwellian with a temperature slightly higher than the central electron temperature. Scalings with plasma current, as well as correlations with local Hα measurements and radial dependences, are presented. (author)

  18. Measurements of hot electrons in the Extrap T1 reversed-field pinch

    Science.gov (United States)

    Welander, A.; Bergsåker, H.

    1998-02-01

    The presence of an anisotropic energetic electron population in the edge region is a characteristic feature of reversed-field pinch (RFP) plasmas. In the Extrap T1 RFP, the anisotropic, parallel heat flux in the edge region measured by calorimetry was typically several hundred 0741-3335/40/2/011/img1. To gain more insight into the origin of the hot electron component and to achieve time resolution of the hot electron flow during the discharge, a target probe with a soft x-ray monitor was designed, calibrated and implemented. The x-ray emission from the target was measured with a surface barrier detector covered with a set of different x-ray filters to achieve energy resolution. A calibration in the range 0.5-2 keV electron energy was performed on the same target and detector assembly using a 0741-3335/40/2/011/img2 cathode electron gun. The calibration data are interpolated and extrapolated numerically. A directional asymmetry of more than a factor of 100 for the higher energy electrons is observed. The hot electrons are estimated to constitute 10% of the total electron density at the edge and their energy distribution is approximated by a half-Maxwellian with a temperature slightly higher than the central electron temperature. Scalings with plasma current, as well as correlations with local 0741-3335/40/2/011/img3 measurements and radial dependences, are presented.

  19. High-Current Gain Two-Dimensional MoS 2 -Base Hot-Electron Transistors

    KAUST Repository

    Torres, Carlos M.

    2015-12-09

    The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications. © 2015 American Chemical Society.

  20. High-Current Gain Two-Dimensional MoS 2 -Base Hot-Electron Transistors

    KAUST Repository

    Torres, Carlos M.; Lan, Yann Wen; Zeng, Caifu; Chen, Jyun Hong; Kou, Xufeng; Navabi, Aryan; Tang, Jianshi; Montazeri, Mohammad; Adleman, James R.; Lerner, Mitchell B.; Zhong, Yuan Liang; Li, Lain-Jong; Chen, Chii Dong; Wang, Kang L.

    2015-01-01

    The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications. © 2015 American Chemical Society.

  1. Plasmonic photocatalytic reactions enhanced by hot electrons in a one-dimensional quantum well

    Directory of Open Access Journals (Sweden)

    H. J. Huang

    2015-11-01

    Full Text Available The plasmonic endothermic oxidation of ammonium ions in a spinning disk reactor resulted in light energy transformation through quantum hot charge carriers (QHC, or quantum hot electrons, during a chemical reaction. It is demonstrated with a simple model that light of various intensities enhance the chemical oxidization of ammonium ions in water. It was further observed that light illumination, which induces the formation of plasmons on a platinum (Pt thin film, provided higher processing efficiency compared with the reaction on a bare glass disk. These induced plasmons generate quantum hot electrons with increasing momentum and energy in the one-dimensional quantum well of a Pt thin film. The energy carried by the quantum hot electrons provided the energy needed to catalyze the chemical reaction. The results indicate that one-dimensional confinement in spherical coordinates (i.e., nanoparticles is not necessary to provide an extra excited state for QHC generation; an 8 nm Pt thin film for one-dimensional confinement in Cartesian coordinates can also provide the extra excited state for the generation of QHC.

  2. Experimental studies on the production and suppression mechanism of the hot electrons produced by short wavelength laser

    International Nuclear Information System (INIS)

    Qi Lanying; Jiang Xiaohua; Zhao Xuewei; Li Sanwei; Zhang Wenhai; Li Chaoguang; Zheng Zhijian; Ding Yongkun

    1999-12-01

    The experiments on gold-disk and hohlraum and plastic hydrocarbon (CH) film targets irradiated by laser beams with wavelength 0.35 μm (Xingguang-II) and 0.53 μm (Shenguang-I) are performed. The characteristics of hot electrons are commonly deduced from spectrum of hard X-ray. Associated with the measurement of backward SRS and 3/2ω 0 , the production mechanism of hot electrons for different target type is analyzed in laser plasma with shorter wavelength. A effective way to suppress hot electrons has been found

  3. Hot electron spatial distribution under presence of laser light self-focusing in over-dense plasmas

    International Nuclear Information System (INIS)

    Tanimoto, T; Yabuuchi, T; Habara, H; Kondo, K; Kodama, R; Mima, K; Tanaka, K A; Lei, A L

    2008-01-01

    In fast ignition for laser thermonuclear fusion, an ultra intense laser (UIL) pulse irradiates an imploded plasma in order to fast-heat a high-density core with hot electrons generated in laser-plasma interactions. An UIL pulse needs to make plasma channel via laser self-focusing and to propagate through the corona plasma to reach close enough to the core. Hot electrons are used for heating the core. Therefore the propagation of laser light in the high-density plasma region and spatial distribution of hot electron are important in issues in order to study the feasibility of this scheme. We measure the spatial distribution of hot electron when the laser light propagates into the high-density plasma region by self-focusing

  4. Experimental study for angular distribution of the hot electrons generated by femtosecond laser interaction with solid targets

    International Nuclear Information System (INIS)

    Cai, D.F.; Gu, Y.Q.; Zheng, Z.J.; Wen, T.S.; Chunyu, S.T.; Wang, Z.B.; Yang, X.D.

    2003-01-01

    The experimental results of angular distribution of hot electrons in the interaction of a 60 fs, 125 mJ, 800 nm, ∼10 17 W cm -2 laser pulse with Al targets are reported. Three obvious peaks of hot electrons emission have been observed, as there is a weak normal component of the laser electric field. These emission peaks are located in the directions of the specular reflection of the laser, the target normal, and the backreflection of the laser, respectively. In the case of the P-polarized laser pulse, which has a strong normal component of the laser electric field, the peak in the backreflection of the laser disappeared, and only two obvious peaks of hot electron emissions existed. It shows that the different directions of hot electrons emission are dominated by different absorption or acceleration mechanisms. The experimental result of the hot electrons energy spectrum at the target normal shows that the effective temperature of hot electrons is about 190 keV, which is consistent with a scaling law of the resonance absorption

  5. Proton probe measurement of fast advection of magnetic fields by hot electrons

    International Nuclear Information System (INIS)

    Willingale, L; Thomas, A G R; Nilson, P M; Kaluza, M C; Dangor, A E; Evans, R G; Fernandes, P; Haines, M G; Kamperidis, C; Kingham, R J; Ridgers, C P; Sherlock, M; Wei, M S; Najmudin, Z; Krushelnick, K; Bandyopadhyay, S; Notley, M; Minardi, S; Rozmus, W; Tatarakis, M

    2011-01-01

    A laser generated proton beam was used to measure the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target. At intensities of 10 15 W cm −2 , the significant hot electron production and strong heat fluxes result in non-local transport becoming important to describe the magnetic field dynamics. Two-dimensional implicit Vlasov–Fokker–Planck modeling shows that fast advection of the magnetic field from the focal region occurs via the Nernst effect at significantly higher velocities than the sound speed, v N /c s ≈ 10.

  6. Towards hot electron mediated charge exchange in hyperthermal energy ion-surface interactions

    DEFF Research Database (Denmark)

    Ray, M. P.; Lake, R. E.; Thomsen, Lasse Bjørchmar

    2010-01-01

    shows that the primary energy loss mechanism is the atomic displacement of Au atoms in the thin film of the metal–oxide–semiconductor device. We propose that neutral particle detection of the scattered flux from a biased device could be a route to hot electron mediated charge exchange.......We have made Na + and He + ions incident on the surface of solid state tunnel junctions and measured the energy loss due to atomic displacement and electronic excitations. Each tunnel junction consists of an ultrathin film metal–oxide–semiconductor device which can be biased to create a band of hot...

  7. Non-uniform absorption of terahertz radiation on superconducting hot electron bolometer microbridges

    International Nuclear Information System (INIS)

    Miao, W.; Zhang, W.; Zhong, J. Q.; Shi, S. C.; Delorme, Y.; Lefevre, R.; Feret, A.; Vacelet, T.

    2014-01-01

    We interpret the experimental observation of a frequency-dependence of superconducting hot electron bolometer (HEB) mixers by taking into account the non-uniform absorption of the terahertz radiation on the superconducting HEB microbridge. The radiation absorption is assumed to be proportional to the local surface resistance of the HEB microbridge, which is computed using the Mattis-Bardeen theory. With this assumption the dc and mixing characteristics of a superconducting niobium-nitride (NbN) HEB device have been modeled at frequencies below and above the equilibrium gap frequency of the NbN film

  8. Hot electron transport modelling in fast ignition relevant targets with non-Spitzer resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, D A; Hoarty, D J; Swatton, D J R [Plasma Physics Department, AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Hughes, S J, E-mail: david.chapman@awe.co.u [Computational Physics Group, AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2010-08-01

    The simple Lee-More model for electrical resistivity is implemented in the hybrid fast electron transport code THOR. The model is shown to reproduce experimental data across a wide range of temperatures using a small number of parameters. The effect of this model on the heating of simple Al targets by a short-pulse laser is studied and compared to the predictions of the classical Spitzer-Haerm resistivity. The model is then used in simulations of hot electron transport experiments using buried layer targets.

  9. Capture dynamics of hot electrons on quantum dots in RTDs studied by noise measurement

    International Nuclear Information System (INIS)

    Hees, S S; Kardynal, B E; Shields, A J; Farrer, I; Ritchie, D A

    2008-01-01

    We investigate the noise in quantum dot resonant tunnelling diodes (QDRTDs), where the quantum dots (QDs) placed in the collector experience electric fields that vary in a wide range. The trapping/detrapping of electrons on the QDs dominated the measured electrical noise. The model that we derived for the noise explains the experimental data well. The QD capture cross-section is one to two orders of magnitude smaller than the physical size of the QDs due to the reduced probability of capturing a hot electron on the QD. The model is a powerful tool to design the noise characteristics of QDRTD single photon-detectors

  10. Signatures of hot electrons and fluorescence in Mo Kα emission on Z

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, S. B.; Ampleford, D. J.; Cuneo, M. E.; Jones, B.; Jennings, C. A.; Coverdale, C. A.; Rochau, G. A.; Dunham, G. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Ouart, N.; Dasgupta, A.; Giuliani, J. L. [Naval Research Laboratory, Washington, DC 20375 (United States); Apruzese, J. P. [Consultant to NRL through Engility Corp., Chantilly, Virginia 20151 (United States)

    2014-03-15

    Recent experiments on the Z accelerator have produced high-energy (17 keV) inner-shell K-alpha emission from molybdenum wire array z-pinches. Extensive absolute power and spectroscopic diagnostics along with collisional-radiative modeling enable detailed investigation into the roles of thermal, hot electron, and fluorescence processes in the production of high-energy x-rays. We show that changing the dimensions of the arrays can impact the proportion of thermal and non-thermal K-shell x-rays.

  11. X-rays diagnostics of the hot electron energy distribution in the intense laser interaction with metal targets

    Science.gov (United States)

    Kostenko, O. F.; Andreev, N. E.; Rosmej, O. N.

    2018-03-01

    A two-temperature hot electron energy distribution has been revealed by modeling of bremsstrahlung emission, measured by the radiation attenuation and half-shade methods, and Kα emission from a massive silver cylinder irradiated by a subpicosecond s-polarized laser pulse with a peak intensity of about 2 × 1019 W/cm2. To deduce parameters of the hot electron spectrum, we have developed semi-analytical models of generation and measurements of the x-rays. The models are based on analytical expressions and tabulated data on electron stopping power as well as cross-sections of generation and absorption of the x-rays. The Kα emission from thin silver foils deposited on low-Z substrates, both conducting and nonconducting, has been used to verify the developed models and obtained hot electron spectrum. The obtained temperatures of the colder and hotter electron components are in agreement with the values predicted by kinetic simulations of the cone-guided approach to fast ignition [Chrisman et al., Phys. Plasmas 15, 056309 (2008)]. The temperature of the low-energy component of the accelerated electron spectrum is well below the ponderomotive scaling and Beg's law. We have obtained relatively low conversion efficiency of laser energy into the energy of hot electrons propagating through the solid target of about 2%. It is demonstrated that the assumption about a single-temperature hot electron energy distribution with the slope temperature described by the ponderomotive scaling relationship, without detailed analysis of the hot electron spectrum, can lead to strong overestimation of the laser-to-electron energy-conversion efficiency, in particular, the conversion efficiency of laser energy into the high-temperature component of the hot electron distribution.

  12. Fast ions and hot electrons in the laser--plasma interaction

    International Nuclear Information System (INIS)

    Gitomer, S.J.; Jones, R.D.; Begay, F.; Ehler, A.W.; Kephart, J.F.; Kristal, R.

    1986-01-01

    Data on the emission of energetic ions produced in laser--matter interactions have been analyzed for a wide variety of laser wavelengths, energies, and pulse lengths. Strong correlation has been found between the bulk energy per AMU for fast ions measured by charge cups and the x-ray-determined hot electron temperature. Five theoretical models have been used to explain this correlation. The models include (1) a steady-state spherically symmetric fluid model with classical electron heat conduction, (2) a steady-state spherically symmetric fluid model with flux limited electron heat conduction, (3) a simple analytic model of an isothermal rarefaction followed by a free expansion, (4) the lasneX hydrodynamics code [Comments Plasma Phys. Controlled Fusion 2, 85 (1975)], calculations employing a spherical expansion and simple initial conditions, and (5) the lasneX code with its full array of absorption, transport, and emission physics. The results obtained with these models are in good agreement with the experiments and indicate that the detailed shape of the correlation curve between mean fast ion energy and hot electron temperature is due to target surface impurities at the higher temperatures (higher laser intensities) and to the expansion of bulk target material at the lower temperatures (lower laser intensities)

  13. Submolecular Gates Self-Assemble for Hot-Electron Transfer in Proteins.

    Science.gov (United States)

    Filip-Granit, Neta; Goldberg, Eran; Samish, Ilan; Ashur, Idan; van der Boom, Milko E; Cohen, Hagai; Scherz, Avigdor

    2017-07-27

    Redox reactions play key roles in fundamental biological processes. The related spatial organization of donors and acceptors is assumed to undergo evolutionary optimization facilitating charge mobilization within the relevant biological context. Experimental information from submolecular functional sites is needed to understand the organization strategies and driving forces involved in the self-development of structure-function relationships. Here we exploit chemically resolved electrical measurements (CREM) to probe the atom-specific electrostatic potentials (ESPs) in artificial arrays of bacteriochlorophyll (BChl) derivatives that provide model systems for photoexcited (hot) electron donation and withdrawal. On the basis of computations we show that native BChl's in the photosynthetic reaction center (RC) self-assemble at their ground-state as aligned gates for functional charge transfer. The combined computational and experimental results further reveal how site-specific polarizability perpendicular to the molecular plane enhances the hot-electron transport. Maximal transport efficiency is predicted for a specific, ∼5 Å, distance above the center of the metalized BChl, which is in remarkably close agreement with the distance and mutual orientation of corresponding native cofactors. These findings provide new metrics and guidelines for analysis of biological redox centers and for designing charge mobilizing machines such as artificial photosynthesis.

  14. Conceptual design and simulation investigation of an electronic cooling device powered by hot electrons

    International Nuclear Information System (INIS)

    Su, Guozhen; Zhang, Yanchao; Cai, Ling; Su, Shanhe; Chen, Jincan

    2015-01-01

    Most electronic cooling devices are powered by an external bias applied between the cold and the hot reservoirs. Here we propose a new concept of electronic cooling, in which cooling is achieved by using a reservoir of hot electrons as the power source. The cooling device incorporates two energy filters with the Lorentzian transmission function to respectively select low- and high-energy electrons for transport. Based on the proposed model, we analyze the performances of the device varying with the resonant levels and half widths of two energy filters and establish the optimal configuration of the cooling device. It is believed that such a novel device may be practically used in some nano-energy fields. - Highlights: • A new electronic cooling device powered by hot electrons is proposed. • Two energy filters are employed to select the electrons for transport. • The effects of the resonant levels and half widths of two filters are discussed. • The maximum cooling power and coefficient of performance are calculated. • The optimal configuration of the cooling device is determined.

  15. A memristor-based nonvolatile latch circuit

    International Nuclear Information System (INIS)

    Robinett, Warren; Pickett, Matthew; Borghetti, Julien; Xia Qiangfei; Snider, Gregory S; Medeiros-Ribeiro, Gilberto; Williams, R Stanley

    2010-01-01

    Memristive devices, which exhibit a dynamical conductance state that depends on the excitation history, can be used as nonvolatile memory elements by storing information as different conductance states. We describe the implementation of a nonvolatile synchronous flip-flop circuit that uses a nanoscale memristive device as the nonvolatile memory element. Controlled testing of the circuit demonstrated successful state storage and restoration, with an error rate of 0.1%, during 1000 power loss events. These results indicate that integration of digital logic devices and memristors could open the way for nonvolatile computation with applications in small platforms that rely on intermittent power sources. This demonstrated feasibility of tight integration of memristors with CMOS (complementary metal-oxide-semiconductor) circuitry challenges the traditional memory hierarchy, in which nonvolatile memory is only available as a large, slow, monolithic block at the bottom of the hierarchy. In contrast, the nonvolatile, memristor-based memory cell can be fast, fine-grained and small, and is compatible with conventional CMOS electronics. This threatens to upset the traditional memory hierarchy, and may open up new architectural possibilities beyond it.

  16. Hot electron dynamics at semiconductor surfaces: Implications for quantum dot photovoltaics

    Science.gov (United States)

    Tisdale, William A., III

    Finding a viable supply of clean, renewable energy is one of the most daunting challenges facing the world today. Solar cells have had limited impact in meeting this challenge because of their high cost and low power conversion efficiencies. Semiconductor nanocrystals, or quantum dots, are promising materials for use in novel solar cells because they can be processed with potentially inexpensive solution-based techniques and because they are predicted to have novel optoelectronic properties that could enable the realization of ultra-efficient solar power converters. However, there is a lack of fundamental understanding regarding the behavior of highly-excited, or "hot," charge carriers near quantum-dot and semiconductor interfaces, which is of paramount importance to the rational design of high-efficiency devices. The elucidation of these ultrafast hot electron dynamics is the central aim of this Dissertation. I present a theoretical framework for treating the electronic interactions between quantum dots and bulk semiconductor surfaces and propose a novel experimental technique, time-resolved surface second harmonic generation (TR-SHG), for probing these interactions. I then describe a series of experimental investigations into hot electron dynamics in specific quantum-dot/semiconductor systems. A two-photon photoelectron spectroscopy (2PPE) study of the technologically-relevant ZnO(1010) surface reveals ultrafast (sub-30fs) cooling of hot electrons in the bulk conduction band, which is due to strong electron-phonon coupling in this highly polar material. The presence of a continuum of defect states near the conduction band edge results in Fermi-level pinning and upward (n-type) band-bending at the (1010) surface and provides an alternate route for electronic relaxation. In monolayer films of colloidal PbSe quantum dots, chemical treatment with either hydrazine or 1,2-ethanedithiol results in strong and tunable electronic coupling between neighboring quantum dots

  17. Hot-Electron Bolometer Mixers on Silicon-on-Insulator Substrates for Terahertz Frequencies

    Science.gov (United States)

    Skalare, Anders; Stern, Jeffrey; Bumble, Bruce; Maiwald, Frank

    2005-01-01

    A terahertz Hot-Electron Bolometer (HEB) mixer design using device substrates based on Silicon-On-Insulator (SOI) technology is described. This substrate technology allows very thin chips (6 pm) with almost arbitrary shape to be manufactured, so that they can be tightly fitted into a waveguide structure and operated at very high frequencies with only low risk for power leakages and resonance modes. The NbTiN-based bolometers are contacted by gold beam-leads, while other beamleads are used to hold the chip in place in the waveguide test fixture. The initial tests yielded an equivalent receiver noise temperature of 3460 K double-sideband at a local oscillator frequency of 1.462 THz and an intermediate frequency of 1.4 GHz.

  18. Modeling and Optimization of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applicaitons

    Science.gov (United States)

    Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.; Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.

    1996-01-01

    The development of a YBa(sub 2)Cu(sub 3)O(sub 7-(kronecker delta))(YBCO) hot-electron bolometer (HEB) quasioptical mixer for a 2.5 heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of heat diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated....a single sideband temperature of less than 2000k is predicted.

  19. Hot-Electron Intraband Luminescence from Single Hot Spots in Noble-Metal Nanoparticle Films

    Science.gov (United States)

    Haug, Tobias; Klemm, Philippe; Bange, Sebastian; Lupton, John M.

    2015-08-01

    Disordered noble-metal nanoparticle films exhibit highly localized and stable nonlinear light emission from subdiffraction regions upon illumination by near-infrared femtosecond pulses. Such hot spot emission spans a continuum in the visible and near-infrared spectral range. Strong plasmonic enhancement of light-matter interaction and the resulting complexity of experimental observations have prevented the development of a universal understanding of the origin of light emission. Here, we study the dependence of emission spectra on excitation irradiance and provide the most direct evidence yet that the continuum emission observed from both silver and gold nanoparticle aggregate surfaces is caused by recombination of hot electrons within the conduction band. The electron gas in the emitting particles, which is effectively decoupled from the lattice temperature for the duration of emission, reaches temperatures of several thousand Kelvin and acts as a subdiffraction incandescent light source on subpicosecond time scales.

  20. Hot electron and real space transfer in double-quantum-well structures

    International Nuclear Information System (INIS)

    Okuno, Eiichi; Sawaki, Nobuhiko; Akasaki, Isamu; Kano, Hiroyuki; Hashimoto, Masafumi.

    1991-01-01

    The hot electron phenomena and real space transfer (RST) effect are studied in GaAs/AlGaAs double-quantum-well (DQW) structures, in which we have two kind of quantum wells with different widths. The drift velocity and the electron temperature at liquid helium temperature are investigated as a function of the external electric field applied parallel to the heterointerface. By increasing the field, the electron temperature rises and reaches a plateau in the intermediate region, followed by further rise in the high-field region. The appearance of the plateau is attributed to the RST effect between the two quantum wells. The threshold field for the appearance of the plateau is determined by the difference energy between the quantized levels in two wells. The energy loss rate as a function of the electron temperature indicates that the RST is assisted by LO phonon scattering. (author)

  1. Electric field dependence of the temperature and drift velocity of hot electrons in n-Si

    International Nuclear Information System (INIS)

    Vass, E.

    2001-01-01

    Full text: The average energy- and momentum loss rates of hot electrons interacting simultaneously with acoustic phonons, ionized and neutral impurities in n-Si are calculated quantum theoretically by means of a drifted hot Fermi-Dirac distribution. The drift velocity vd and electron temperature Te occurring in this distribution are determined self-consistently from the force- and power balance equation with respect to the charge neutrality condition. The functions Te(E) and vd(E) calculated in this way are compared with the corresponding relations obtained with help of the simple electron temperature model in order to determine the range of application of this model often used in previous treatises. (author)

  2. Experimental Route to Scanning Probe Hot Electron Nanoscopy (HENs) Applied to 2D Material

    KAUST Repository

    Giugni, Andrea

    2017-06-09

    This paper presents details on a new experimental apparatus implementing the hot electron nanoscopy (HENs) technique introduced for advanced spectroscopies on structure and chemistry in few molecules and interface problems. A detailed description of the architecture used for the laser excitation of surface plasmons at an atomic force microscope (AFM) tip is provided. The photogenerated current from the tip to the sample is detected during the AFM scan. The technique is applied to innovative semiconductors for applications in electronics: 2D MoS2 single crystal and a p-type SnO layer. Results are supported by complementary scanning Kelvin probe microscopy, traditional conductive AFM, and Raman measurements. New features highlighted by HEN technique reveal details of local complexity in MoS2 and polycrystalline structure of SnO at nanometric scale otherwise undetected. The technique set in this paper is promising for future studies in nanojunctions and innovative multilayered materials, with new insight on interfaces.

  3. Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Khurgin, Jacob B., E-mail: jakek@jhu.edu [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Bajaj, Sanyam; Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-12-28

    Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with hot electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.

  4. An Ultrasensitive Hot-Electron Bolometer for Low-Background SMM Applications

    Science.gov (United States)

    Olayaa, David; Wei, Jian; Pereverzev, Sergei; Karasik, Boris S.; Kawamura, Jonathan H.; McGrath, William R.; Sergeev, Andrei V.; Gershenson, Michael E.

    2006-01-01

    We are developing a hot-electron superconducting transition-edge sensor (TES) that is capable of counting THz photons and operates at T = 0.3K. The main driver for this work is moderate resolution spectroscopy (R approx. 1000) on the future space telescopes with cryogenically cooled (approx. 4 K) mirrors. The detectors for these telescopes must be background-limited with a noise equivalent power (NEP) approx. 10(exp -19)-10(exp -20) W/Hz(sup 1/2) over the range v = 0.3-10 THz. Above about 1 THz, the background photon arrival rate is expected to be approx. 10-100/s), and photon counting detectors may be preferable to an integrating type. We fabricated superconducting Ti nanosensors with a volume of approx. 3x10(exp -3) cubic microns on planar substrate and have measured the thermal conductance G to the thermal bath. A very low G = 4x10(exp -14) W/K, measured at 0.3 K, is due to the weak electron-phonon coupling in the material and the thermal isolation provided by superconducting Nb contacts. This low G corresponds to NEP(0.3K) = 3x10(exp -19) W/Hz(sup 1/2). This Hot-Electron Direct Detector (HEDD) is expected to have a sufficient energy resolution for detecting individual photons with v > 0.3 THz at 0.3 K. With the sensor time constant of a few microseconds, the dynamic range is approx. 50 dB.

  5. Hot electron light emission in gallium arsenide/aluminium(x) gallium(1-x) arsenic heterostructures

    Science.gov (United States)

    Teke, Ali

    In this thesis we have demonstrated the operation of a novel tunable wavelength surface light emitting device. The device is based on a p-GaAs, and n-Ga1- xAlxAs heterojunction containing an inversion layer on the p- side, and GaAs quantum wells on the n- side, and, is referred to as HELLISH-2 (Hot Electron Light Emitting and Lasing in Semiconductor Heterostructure-Type 2). The devices utilise hot electron longitudinal transport and, therefore, light emission is independent of the polarity of the applied voltage. The wavelength of the emitted light can be tuned with the applied bias from GaAs band-to-band transition in the inversion layer to e1-hh1 transition in the quantum wells. In this work tunable means that the device can be operated at either single or multiple wavelength emission. The operation of the device requires only two diffused in point contacts. In this project four HELLISH-2 samples coded as ES1, ES2, ES6 and QT919 have been studied. First three samples were grown by MBE and the last one was grown by MOVPE techniques. ES1 was designed for single and double wavelength operation. ES2 was a control sample used to compare our results with previous work on HELLISH-2 and ES6 was designed for single, double and triple wavelength operation. Theoretical modelling of the device operation was carried out and compared with the experimental results. HELLISH-2 structure was optimised for low threshold and high efficiency operation as based on our model calculations. The last sample QT919 has been designed as an optimised device for single and double wavelength operation like ES1. HELLISH-2 has a number of advantages over the conventional light emitters, resulting in some possible applications, such as light logic gates and wavelength division multiplexing in optoelectronic.

  6. Generation and Transport of Hot Electrons in Cone-Wire Targets

    Science.gov (United States)

    Beg, Farhat

    2009-11-01

    We present results from a series of experiments where cone-wire targets in various configurations were employed both to assess hot electron coupling efficiency, and to reveal the source temperature of the hot electrons. Initial experiments were performed on the Vulcan petawatt laser at the Rutherford Appleton Laboratory and Titan laser at the Lawrence Livermore National Laboratory. Results with aluminum cones joined to Cu wires of diameters from 10 to 40 μm show that the laser coupling efficiency to electron energy within the wire is proportional to the cross sectional area of the wire. In addition, coupling into the wire was observed to decrease with the laser prepulse and cone-wall thickness. More recently, this study was extended, using the OMEGA EP laser. The resulting changes in coupling energy give indications of the scaling as we approach FI-relevant conditions. Requirements for FI scale fast ignition cone parameters: tip thickness, wall thickness, laser prepulse and laser pulse length, will be discussed. In collaboration with T. Yabuuchi, T. Ma, D. Higginson, H. Sawada, J. King, M.H. Key, K.U. Akli, Al Elsholz, D. Batani, H. Chen, R.R. Freeman, L. Gizzi, J. Green, S. Hatchett, D. Hey, P. Jaanimagi, J. Koch, K. L. Lancaster, D.Larson, A.J. MacKinnon, H. McLean, A. MacPhee, P.A. Norreys, P.K Patel, R. B. Stephens, W. Theobald, R. Town, M. Wei, S. Wilks, Roger Van Maren, B. Westover and L. VanWoerkom.

  7. Influence of laser induced hot electrons on the threshold for shock ignition of fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Colaïtis, A.; Ribeyre, X.; Le Bel, E.; Duchateau, G.; Nicolaï, Ph.; Tikhonchuk, V. [Centre Lasers Intenses et Applications, Université de Bordeaux - CNRS - CEA, UMR 5107,351 Cours de la Libération, 33400 Talence (France)

    2016-07-15

    The effects of Hot Electrons (HEs) generated by the nonlinear Laser-Plasma Interaction (LPI) on the dynamics of Shock Ignition Inertial Confinement Fusion targets are investigated. The coupling between the laser beam, plasma dynamics and hot electron generation and propagation is described with a radiative hydrodynamics code using an inline model based on Paraxial Complex Geometrical Optics [Colaïtis et al., Phys. Rev. E 92, 041101 (2015)]. Two targets are considered: the pure-DT HiPER target and a CH-DT design with baseline spike powers of the order of 200–300 TW. In both cases, accounting for the LPI-generated HEs leads to non-igniting targets when using the baseline spike powers. While HEs are found to increase the ignitor shock pressure, they also preheat the bulk of the imploding shell, notably causing its expansion and contamination of the hotspot with the dense shell material before the time of shock convergence. The associated increase in hotspot mass (i) increases the ignitor shock pressure required to ignite the fusion reactions and (ii) significantly increases the power losses through Bremsstrahlung X-ray radiation, thus rapidly cooling the hotspot. These effects are less prominent for the CH-DT target where the plastic ablator shields the lower energy LPI-HE spectrum. Simulations using higher laser spike powers of 500 TW suggest that the CH-DT capsule marginally ignites, with an ignition window width significantly smaller than without LPI-HEs, and with three quarters of the baseline target yield. The latter effect arises from the relation between the shock launching time and the shell areal density, which becomes relevant in presence of a LPI-HE preheating.

  8. Prediction of hot electron production by ultraintense KrF laser-plasma interactions on solid-density targets

    International Nuclear Information System (INIS)

    Kato, Susumu; Takahashi, Eiichi; Miura, Eisuke; Owadano, Yoshiro; Nakamura, Tatsufumi; Kato, Tomokazu

    2002-01-01

    The scaling of hot electron temperature and the spectrum of electron energy by intense laser plasma interactions are reexamined from a viewpoint of the difference in laser wavelength. Laser plasma interaction such as parametric instabilities is usually determined by the Iλ2 scaling, where I and λ is the laser intensity and wavelength, respectively. However, the hot electron temperature is proportional to (ncr/ne0)1/2 [(1 + a 0 2 ) 1/2 - 1] rather than [(1 + a 0 2 ) 1/2 - 1] at the interaction with overdense plasmas, where ne0 is a electron density of overdense plasmas and a0 is a normalized laser intensity

  9. Identification of conduction and hot electron property in ZnS, ZnO and SiO2

    International Nuclear Information System (INIS)

    Huang Jinzhao; Xu Zheng; Zhao Suling; Li Yuan; Yuan Guangcai; Wang Yongsheng; Xu Xurong

    2007-01-01

    The impact excitation and ionization is the most important process in layered optimization scheme and solid state cathodoluminescence. The conduction property (semiconductor property) of SiO 2 , ZnS and ZnO is studied based on organic/inorganic electroluminescence. The hot electron property (acceleration and multiplication property) of SiO 2 and ZnS is investigated based on the solid state cathodoluminescence. The results show that the SiO 2 has the fine hot electron property and the conduction property is not as good as ZnO and ZnS

  10. Organic non-volatile memories from ferroelectric phase-separated blends

    Science.gov (United States)

    Asadi, Kamal; de Leeuw, Dago M.; de Boer, Bert; Blom, Paul W. M.

    2008-07-01

    New non-volatile memories are being investigated to keep up with the organic-electronics road map. Ferroelectric polarization is an attractive physical property as the mechanism for non-volatile switching, because the two polarizations can be used as two binary levels. However, in ferroelectric capacitors the read-out of the polarization charge is destructive. The functionality of the targeted memory should be based on resistive switching. In inorganic ferroelectrics conductivity and ferroelectricity cannot be tuned independently. The challenge is to develop a storage medium in which the favourable properties of ferroelectrics such as bistability and non-volatility can be combined with the beneficial properties provided by semiconductors such as conductivity and rectification. Here we present an integrated solution by blending semiconducting and ferroelectric polymers into phase-separated networks. The polarization field of the ferroelectric modulates the injection barrier at the semiconductor-metal contact. The combination of ferroelectric bistability with (semi)conductivity and rectification allows for solution-processed non-volatile memory arrays with a simple cross-bar architecture that can be read out non-destructively. The concept of an electrically tunable injection barrier as presented here is general and can be applied to other electronic devices such as light-emitting diodes with an integrated on/off switch.

  11. Nonvolatile Memory Technology for Space Applications

    Science.gov (United States)

    Oldham, Timothy R.; Irom, Farokh; Friendlich, Mark; Nguyen, Duc; Kim, Hak; Berg, Melanie; LaBel, Kenneth A.

    2010-01-01

    This slide presentation reviews several forms of nonvolatile memory for use in space applications. The intent is to: (1) Determine inherent radiation tolerance and sensitivities, (2) Identify challenges for future radiation hardening efforts, (3) Investigate new failure modes and effects, and technology modeling programs. Testing includes total dose, single event (proton, laser, heavy ion), and proton damage (where appropriate). Test vehicles are expected to be a variety of non-volatile memory devices as available including Flash (NAND and NOR), Charge Trap, Nanocrystal Flash, Magnetic Memory (MRAM), Phase Change--Chalcogenide, (CRAM), Ferroelectric (FRAM), CNT, and Resistive RAM.

  12. Nonvolatile Rad-Hard Holographic Memory

    Science.gov (United States)

    Chao, Tien-Hsin; Zhou, Han-Ying; Reyes, George; Dragoi, Danut; Hanna, Jay

    2001-01-01

    We are investigating a nonvolatile radiation-hardened (rad-hard) holographic memory technology. Recently, a compact holographic data storage (CHDS) breadboard utilizing an innovative electro-optic scanner has been built and demonstrated for high-speed holographic data storage and retrieval. The successful integration of this holographic memory breadboard has paved the way for follow-on radiation resistance test of the photorefractive (PR) crystal, Fe:LiNbO3. We have also started the investigation of using two-photon PR crystals that are doubly doped with atoms of iron group (Ti, Cr, Mn, Cu) and of rare-earth group (Nd, Tb) for nonvolatile holographic recordings.

  13. Monte Carlo study of electron-plasmon scattering effects on hot electron transport in GaAs

    International Nuclear Information System (INIS)

    Popov, V.V.; Bagaeva, T.Yu.; Solodkaya, T.I.

    1994-07-01

    It is shown using Monte Carlo simulation that electron-plasmon scattering affects substantially the hot-electron energy distribution function and transport properties in bulk GaAs. However, this effect is found to be much less than that predicted in earlier paper of other authors. (author). 5 refs, 7 figs

  14. Organic Nonvolatile Memory Devices Based on Ferroelectricity

    NARCIS (Netherlands)

    Naber, Ronald C. G.; Asadi, Kamal; Blom, Paul W. M.; de Leeuw, Dago M.; de Boer, Bert

    2010-01-01

    A memory functionality is a prerequisite for many applications of electronic devices. Organic nonvolatile memory devices based on ferroelectricity are a promising approach toward the development of a low-cost memory technology. In this Review Article we discuss the latest developments in this area

  15. Organic nonvolatile memory devices based on ferroelectricity

    NARCIS (Netherlands)

    Naber, R.C.G.; Asadi, K.; Blom, P.W.M.; Leeuw, D.M. de; Boer, B. de

    2010-01-01

    A memory functionality is a prerequisite for many applications of electronic devices. Organic nonvolatile memory devices based on ferroelectricity are a promising approach toward the development of a low-cost memory technology. In this Review Article we discuss the latest developments in this area

  16. Evaluation of Recent Technologies of Nonvolatile RAM

    Science.gov (United States)

    Nuns, Thierry; Duzellier, Sophie; Bertrand, Jean; Hubert, Guillaume; Pouget, Vincent; Darracq, FrÉdÉric; David, Jean-Pierre; Soonckindt, Sabine

    2008-08-01

    Two types of recent nonvolatile random access memories (NVRAM) were evaluated for radiation effects: total dose and single event upset and latch-up under heavy ions and protons. Complementary irradiation with a laser beam provides information on sensitive areas of the devices.

  17. Probing hot-electron effects in wide area plasmonic surfaces using X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ayas, Sencer; Cupallari, Andi; Dana, Aykutlu, E-mail: aykutlu@unam.bilkent.edu.tr [UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

    2014-12-01

    Plasmon enhanced hot carrier formation in metallic nanostructures increasingly attracts attention due to potential applications in photodetection, photocatalysis, and solar energy conversion. Here, hot-electron effects in nanoscale metal-insulator-metal (MIM) structures are investigated using a non-contact X-ray photoelectron spectroscopy based technique using continuous wave X-ray and laser excitations. The effects are observed through shifts of the binding energy of the top metal layer upon excitation with lasers of 445, 532, and 650 nm wavelength. The shifts are polarization dependent for plasmonic MIM grating structures fabricated by electron beam lithography. Wide area plasmonic MIM surfaces fabricated using a lithography free route by the dewetting of evaporated Ag on HfO{sub 2} exhibit polarization independent optical absorption and surface photovoltage. Using a simple model and making several assumptions about the magnitude of the photoemission current, the responsivity and external quantum efficiency of wide area plasmonic MIM surfaces are estimated as 500 nA/W and 11 × 10{sup −6} for 445 nm illumination.

  18. Hot-electron bolometer terahertz mixers for the Herschel Space Observatory.

    Science.gov (United States)

    Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Khosropanah, Pourya; Kollberg, Erik

    2008-03-01

    We report on low noise terahertz mixers (1.4-1.9 THz) developed for the heterodyne spectrometer onboard the Herschel Space Observatory. The mixers employ double slot antenna integrated superconducting hot-electron bolometers (HEBs) made of thin NbN films. The mixer performance was characterized in terms of detection sensitivity across the entire rf band by using a Fourier transform spectrometer (from 0.5 to 2.5 THz, with 30 GHz resolution) and also by measuring the mixer noise temperature at a limited number of discrete frequencies. The lowest mixer noise temperature recorded was 750 K [double sideband (DSB)] at 1.6 THz and 950 K DSB at 1.9 THz local oscillator (LO) frequencies. Averaged across the intermediate frequency band of 2.4-4.8 GHz, the mixer noise temperature was 1100 K DSB at 1.6 THz and 1450 K DSB at 1.9 THz LO frequencies. The HEB heterodyne receiver stability has been analyzed and compared to the HEB stability in the direct detection mode. The optimal local oscillator power was determined and found to be in a 200-500 nW range.

  19. YBCO hot-electron bolometers dedicated to THz detection and imaging: Embedding issues

    International Nuclear Information System (INIS)

    Aurino, M; Tuerer, I; Martinez, A; Gensbittel, A; Degardin, A F; Kreisler, A J

    2010-01-01

    High-T c hot-electron bolometers (HEB) are an interesting alternative to other superconducting heterodyne mixers in the terahertz frequency range because of low-cost cooling investment, ultra-wide instantaneous bandwidth and low intrinsic noise level, even at 80 K. A technological process to fabricate stacked yttrium-based (YBCO) / praseodymium-based (PBCO) ultra-thin films (in the 15 to 40 nm thickness range) etched to form 0.5 μm x 0.5 μm constrictions, elaborated on (100) MgO substrates, has been previously described. Ageing effects were also considered, with the consequence of increased electrical resistance, significant degradation of the regular THz response and no HEB mixing action. Electron and UV lithography steps are revisited here to realize HEB mixers based on nano-bridges covered by a log-periodic planar gold antenna, dedicated to the 1 to 7 THz range. Several measures have been attempted to reduce the conversion losses, mainly by considering the embedding issues related to the YBCO nano-bridge impedance matching to the antenna and the design of optimized intermediate frequency circuitry. Antenna simulations were performed and validated through experiments on scaled models at GHz frequencies. Electromagnetic coupling to the incoming radiation was also studied, including crosstalk between neighbour antennas forming a linear imaging array.

  20. Analysis of a high-Tc hot-electron superconducting mixer for terahertz applications

    International Nuclear Information System (INIS)

    Karasik, B.S.; McGrath, W.R.; Gaidis, M.C.

    1997-01-01

    The prospects of a YBa 2 Cu 3 O 7-δ hot-electron bolometer mixer for a THz heterodyne receiver are discussed. The modeled device is a submicron bridge made from a 10-nm-thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of phonon diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated. The intrinsic conversion efficiency and the noise temperature have been calculated as functions of the device size, local oscillator (LO) power, and ambient temperature. Assuming thermal fluctuations and Johnson noise to be the main sources of noise, a minimum single sideband mixer noise temperature of congruent 2000 K is predicted. For our modeled device the intrinsic conversion loss at an intermediate frequency of 2.5 GHz is less than 10 dB and the required LO power is ∼1 endash 10 μW. copyright 1997 American Institute of Physics

  1. Terahertz imaging and spectroscopy based on hot electron bolometer (HEB) heterodyne detection

    Science.gov (United States)

    Gerecht, Eyal; You, Lixing

    2008-02-01

    Imaging and spectroscopy at terahertz frequencies have great potential for healthcare, plasma diagnostics, and homeland security applications. Terahertz frequencies correspond to energy level transitions of important molecules in biology and astrophysics. Terahertz radiation (T-rays) can penetrate clothing and, to some extent, can also penetrate biological materials. Because of their shorter wavelengths, they offer higher spatial resolution than do microwaves or millimeter waves. We are developing hot electron bolometer (HEB) mixer receivers for heterodyne detection at terahertz frequencies. HEB detectors provide unprecedented sensitivity and spectral resolution at terahertz frequencies. We describe the development of a two-pixel focal plane array (FPA) based on HEB technology. Furthermore, we have demonstrated a fully automated, two-dimensional scanning, passive imaging system based on our HEB technology operating at 0.85 THz. Our high spectral resolution terahertz imager has a total system noise equivalent temperature difference (NEΔT) value of better than 0.5 K and a spatial resolution of a few millimeters. HEB technology is becoming the basis for advanced terahertz imaging and spectroscopic technologies for the study of biological and chemical agents over the entire terahertz spectrum.

  2. Low-Noise Wide Bandwith, Hot Electron Bolometer Mixers for Submillimeter Wavelengths

    Science.gov (United States)

    McGrath, W. R.

    1995-01-01

    Recently a novel superconductive hot-electron micro-bolometer has been proposed which is both fast and sensitive (D. E. Prober, Appl. Phys. Lett. 62, 2119, 1993). This device has several important properties which make it useful as a heterodyne sensor for radioastronomy applications at frequencies above 1 THz. The thermal response time of the device is fast enough, several 10's of picoseconds, to allow for IF's of several GHz. This bolometer mixer should operate well up to at least 10 THz. There is no energy gap limitation as in an SIS mixer, since the mixing process relies on heating of the electron gas. In fact, rf power is absorbed more uniformly above the gap frequency. The mixer noise should be near quantum-limited, and the local oscillator (LO) power requirement is very low: / 10 nW for a Nb device. One of the unique features of this device is that it employs rapid electron diffusion into a normal metal, rather than phonon emission, as the thermal conductance that cools the heated electrons. In order for diffusion to dominate over phonon emission, the device must be short, less than 0.5.

  3. Infrared hot-electron NbN superconducting photodetectors for imaging applications

    International Nuclear Information System (INIS)

    Il'in, K.S.; Gol'tsman, G.N.; Verevkin, A.A.; Sobolewski, Roman

    1999-01-01

    We report an effective quantum efficiency of 340, responsivity >200 A W -1 (>10 4 V W -1 ) and response time of 27±5 ps at temperatures close to the superconducting transition for NbN superconducting hot-electron photodetectors (HEPs) in the near-infrared and optical ranges. Our studies were performed on a few nm thick NbN films deposited on sapphire substrates and patterned into μm-size multibridge detector structures, incorporated into a coplanar transmission line. The time-resolved photoresponse was studied by means of subpicosecond electro-optic sampling with 100 fs wide laser pulses. The quantum efficiency and responsivity studies of our photodetectors were conducted using an amplitude-modulated infrared beam, fibre-optically coupled to the device. The observed picosecond response time and the very high efficiency and sensitivity of the NbN HEPs make them an excellent choice for infrared imaging photodetectors and input optical-to-electrical transducers for superconducting digital circuits. (author)

  4. Laser generated hot electron transport in an externally applied magnetic field

    International Nuclear Information System (INIS)

    Burnett, N.H.; Enright, G.D.

    1986-01-01

    The authors have investigated the effect of an externally applied DC magnetic field on the generation and transport of hot electrons in CO/sub 2/ laser irradiation of cylindrical targets. The targets used in these studies were 6.3 mm diameter metal rods through which a pulsed current was driven from an external capacitor. Magnetic fields up to 150 kgauss were produced at the target surface. The CO/sub 2/ laser was focused with an f/5 lens resulting in a laser intensity of ≅3 x 10/sup 14/ W/cm/sup 2/ in a 100 μm diameter focal spot. The effect of the external magnetic field on the generation and inward transport of superhot (≥ 100 keV) electrons was studied. Principal diagnostics included a six channel hard x-ray spectrometer, a high energy x-ray pinhole camera, a LiF Laue x-ray spectrograph and a Ross-filtered (W-Ta) pair of x-ray detectors. The latter two diagnostics were designed to detect Au Kα /sub emission at 68.2 keV

  5. Fabrication of an Aluminum Based Hot Electron Mixer for Terahertz Applications

    Science.gov (United States)

    Echternach, P. M.; LeDuc, H. G.; Skalare, A.; McGrath, W. R.

    2000-01-01

    Aluminum based diffusion cooled hot electron bolometers (HEB) mixers, predicted to have better noise, bandwidth and to require less LO power than Nb based diffusion cooled HEBs, have been fabricated. Preliminary DC tests were performed. The bolometer elements consisted of short (0.1 to 0.3 micron), narrow (0.08 to 0. 15 micron) and thin (11 nm) aluminum wires connected to large contact pads consisting of a novel trilayer Al/Ti/Au. The patterns were defined by electron beam lithography and the metal deposition involved a double angle process, the Aluminum wires being deposited straight on and the pads being deposited at a 45 degree angle without breaking vacuum. The Al/Ti/Au trilayer was developed to provide a way of making contact between the aluminum wire and the gold antenna. The Titanium layer acts as a diffusion barrier to avoid damage of the Aluminum contact and bolometer wire and to lower the transition temperature of the pads to below that of the bolometer wire. The Au layer avoids the formation of an oxide on the Ti layer and provides good electrical contact to the IF/antenna structure. The resistance of the bolometers as a function of temperature was measured. It is clear that below the transition temperature of the wire (1.8K) but above the transition temperature of the contact pads (0.6K), the proximity effect drives most of the bolometer wire normal, causing a very broad transition. This effect should not affect the performance of the bolometers since they will be operated at a temperature below the TC of the pads. This is evident from the IV characteristics measured at 0.3K. RF characterization tests will begin shortly.

  6. Hot-electron plasma formation and confinement in the tandem mirror experiment-upgrade

    International Nuclear Information System (INIS)

    Ress, D.B.

    1988-06-01

    The tandem mirror experiment-upgrade (TMX-U) at the Lawrence Livermore National Laboratory (LLNL) is the first experiment to investigate the thermal-barrier tandem-mirror concept. One attractive feature of the tandem magnetic mirror as a commercial power reactor is that the fusion reactions occur in an easily accessible center-cell. On the other hand, complicated end-cells are necessary to provide magnetohydrodynamic (MHD) stability and improved particle confinement of the center-cell plasma. In these end-cells, enhanced confinement is achieved with a particular axial potential profile that is formed with electron-cyclotron range-of-frequency heating (ECRF heating, ECRH). By modifying the loss rates of electrons at spatially distinct locations within the end-cells, the ECRH can tailor the plasma potential profile in the desired fashion. Specifically, the thermal-barrier concept requires generation of a population of energetic electrons near the midplane of each end-cell. To be effective, the transverse (to the magnetic field) spatial structure of the hot-electron plasma must be fairly uniform. In this dissertation we characterize the spatial structure of the ECRH-generated plasma, and determine how the structure builds up in time. Furthermore, the plasma should efficiently absorb the ECRF power, and a large fraction of the electrons must be well confined near the end-cell midplane. Therefore, we also examine in detail the ECRH power balance, determining how the ECRF power is absorbed by the plasma, and the processes through which that power is confined and lost. 43 refs., 69 figs., 6 tabs

  7. Influence of lateral target size on hot electron production and electromagnetic pulse emission from laser-irradiated metallic targets

    International Nuclear Information System (INIS)

    Chen Ziyu; Li Jianfeng; Yu Yong; Li Xiaoya; Peng Qixian; Zhu Wenjun; Wang Jiaxiang

    2012-01-01

    The influences of lateral target size on hot electron production and electromagnetic pulse emission from laser interaction with metallic targets have been investigated. Particle-in-cell simulations at high laser intensities show that the yield of hot electrons tends to increase with lateral target size, because the larger surface area reduces the electrostatic field on the target, owing to its expansion along the target surface. At lower laser intensities and longer time scales, experimental data characterizing electromagnetic pulse emission as a function of lateral target size also show target-size effects. Charge separation and a larger target tending to have a lower target potential have both been observed. The increase in radiation strength and downshift in radiation frequency with increasing lateral target size can be interpreted using a simple model of the electrical capacity of the target.

  8. Influence of lateral target size on hot electron production and electromagnetic pulse emission from laser-irradiated metallic targets

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ziyu; Li Jianfeng; Yu Yong; Li Xiaoya; Peng Qixian; Zhu Wenjun [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Wang Jiaxiang [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)

    2012-11-15

    The influences of lateral target size on hot electron production and electromagnetic pulse emission from laser interaction with metallic targets have been investigated. Particle-in-cell simulations at high laser intensities show that the yield of hot electrons tends to increase with lateral target size, because the larger surface area reduces the electrostatic field on the target, owing to its expansion along the target surface. At lower laser intensities and longer time scales, experimental data characterizing electromagnetic pulse emission as a function of lateral target size also show target-size effects. Charge separation and a larger target tending to have a lower target potential have both been observed. The increase in radiation strength and downshift in radiation frequency with increasing lateral target size can be interpreted using a simple model of the electrical capacity of the target.

  9. Effect of excess superthermal hot electrons on finite amplitude ion-acoustic solitons and supersolitons in a magnetized auroral plasma

    Energy Technology Data Exchange (ETDEWEB)

    Rufai, O. R., E-mail: rrufai@csir.co.za [Council for Scientific and Industrial Research, Pretoria (South Africa); Bharuthram, R., E-mail: rbharuthram@uwc.ac.za [University of the Western Cape, Bellville (South Africa); Singh, S. V., E-mail: satyavir@iigs.iigm.res.in; Lakhina, G. S., E-mail: lakhina@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel (W), Navi, Mumbai-410218 (India)

    2015-10-15

    The effect of excess superthermal electrons is investigated on finite amplitude nonlinear ion-acoustic waves in a magnetized auroral plasma. The plasma model consists of a cold ion fluid, Boltzmann distribution of cool electrons, and kappa distributed hot electron species. The model predicts the evolution of negative potential solitons and supersolitons at subsonic Mach numbers region, whereas, in the case of Cairn's nonthermal distribution model for the hot electron species studied earlier, they can exist both in the subsonic and supersonic Mach number regimes. For the dayside auroral parameters, the model generates the super-acoustic electric field amplitude, speed, width, and pulse duration of about 18 mV/m, 25.4 km/s, 663 m, and 26 ms, respectively, which is in the range of the Viking spacecraft measurements.

  10. Reliable determination of the Cu/n-Si Schottky barrier height by using in-device hot-electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Parui, Subir, E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu; Atxabal, Ainhoa; Ribeiro, Mário; Bedoya-Pinto, Amilcar; Sun, Xiangnan; Llopis, Roger [CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country (Spain); Casanova, Fèlix; Hueso, Luis E., E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu [CIC nanoGUNE, 20018 Donostia-San Sebastian, Basque Country (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Basque Country (Spain)

    2015-11-02

    We show the operation of a Cu/Al{sub 2}O{sub 3}/Cu/n-Si hot-electron transistor for the straightforward determination of a metal/semiconductor energy barrier height even at temperatures below carrier-freeze out in the semiconductor. The hot-electron spectroscopy measurements return a fairly temperature independent value for the Cu/n-Si barrier of 0.66 ± 0.04 eV at temperatures below 180 K, in substantial accordance with mainstream methods based on complex fittings of either current-voltage (I-V) and capacitance-voltage (C-V) measurements. The Cu/n-Si hot-electron transistors exhibit an OFF current of ∼2 × 10{sup −13} A, an ON/OFF ratio of ∼10{sup 5}, and an equivalent subthreshold swing of ∼96 mV/dec at low temperatures, which are suitable values for potential high frequency devices.

  11. Reliable determination of the Cu/n-Si Schottky barrier height by using in-device hot-electron spectroscopy

    International Nuclear Information System (INIS)

    Parui, Subir; Atxabal, Ainhoa; Ribeiro, Mário; Bedoya-Pinto, Amilcar; Sun, Xiangnan; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.

    2015-01-01

    We show the operation of a Cu/Al 2 O 3 /Cu/n-Si hot-electron transistor for the straightforward determination of a metal/semiconductor energy barrier height even at temperatures below carrier-freeze out in the semiconductor. The hot-electron spectroscopy measurements return a fairly temperature independent value for the Cu/n-Si barrier of 0.66 ± 0.04 eV at temperatures below 180 K, in substantial accordance with mainstream methods based on complex fittings of either current-voltage (I-V) and capacitance-voltage (C-V) measurements. The Cu/n-Si hot-electron transistors exhibit an OFF current of ∼2 × 10 −13  A, an ON/OFF ratio of ∼10 5 , and an equivalent subthreshold swing of ∼96 mV/dec at low temperatures, which are suitable values for potential high frequency devices

  12. Spin-dependent hot electron transport and nano-scale magnetic imaging of metal/Si structures

    International Nuclear Information System (INIS)

    Kaidatzis, A.

    2008-10-01

    In this work, we experimentally study spin-dependent hot electron transport through metallic multilayers (ML), containing single magnetic layers or 'spin-valve' (SV) tri layers. For this purpose, we have set up a ballistic electron emission microscope (BEEM), a three terminal extension of scanning tunnelling microscopy on metal/semiconductor structures. The implementation of the BEEM requirements into the sample fabrication is described in detail. Using BEEM, the hot electron transmission through the ML's was systematically measured in the energy range 1-2 eV above the Fermi level. By varying the magnetic layer thickness, the spin-dependent hot electron attenuation lengths were deduced. For the materials studied (Co and NiFe), they were compared to calculations and other determinations in the literature. For sub-monolayer thickness, a non uniform morphology was observed, with large transmission variations over sub-nano-metric distances. This effect is not yet fully understood. In the imaging mode, the magnetic configurations of SV's were studied under field, focusing on 360 degrees domain walls in Co layers. The effects of the applied field intensity and direction on the DW structure were studied. The results were compared quantitatively to micro-magnetic calculations, with an excellent agreement. From this, it can be shown that the BEEM magnetic resolution is better than 50 nm. (author)

  13. Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments.

    Science.gov (United States)

    Rosenberg, M J; Solodov, A A; Myatt, J F; Seka, W; Michel, P; Hohenberger, M; Short, R W; Epstein, R; Regan, S P; Campbell, E M; Chapman, T; Goyon, C; Ralph, J E; Barrios, M A; Moody, J D; Bates, J W

    2018-02-02

    Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (∼500 to 700  μm), electron temperature (∼3 to 5 keV), and laser intensity (6 to 16×10^{14}  W/cm^{2}) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ∼0.7% to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ∼4×10^{14} to ∼6×10^{14}  W/cm^{2}. These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

  14. Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments

    Science.gov (United States)

    Rosenberg, M. J.; Solodov, A. A.; Myatt, J. F.; Seka, W.; Michel, P.; Hohenberger, M.; Short, R. W.; Epstein, R.; Regan, S. P.; Campbell, E. M.; Chapman, T.; Goyon, C.; Ralph, J. E.; Barrios, M. A.; Moody, J. D.; Bates, J. W.

    2018-01-01

    Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (˜500 to 700 μ m ), electron temperature (˜3 to 5 keV), and laser intensity (6 to 16 ×1014 W /cm2 ) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ˜0.7 % to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ˜4×10 14 to ˜6 ×1014 W /cm2 . These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

  15. Electrostatically telescoping nanotube nonvolatile memory device

    International Nuclear Information System (INIS)

    Kang, Jeong Won; Jiang Qing

    2007-01-01

    We propose a nonvolatile memory based on carbon nanotubes (CNTs) serving as the key building blocks for molecular-scale computers and investigate the dynamic operations of a double-walled CNT memory element by classical molecular dynamics simulations. The localized potential energy wells achieved from both the interwall van der Waals energy and CNT-metal binding energy make the bistability of the CNT positions and the electrostatic attractive forces induced by the voltage differences lead to the reversibility of this CNT memory. The material for the electrodes should be carefully chosen to achieve the nonvolatility of this memory. The kinetic energy of the CNT shuttle experiences several rebounds induced by the collisions of the CNT onto the metal electrodes, and this is critically important to the performance of such an electrostatically telescoping CNT memory because the collision time is sufficiently long to cause a delay of the state transition

  16. Carbon nanomaterials for non-volatile memories

    Science.gov (United States)

    Ahn, Ethan C.; Wong, H.-S. Philip; Pop, Eric

    2018-03-01

    Carbon can create various low-dimensional nanostructures with remarkable electronic, optical, mechanical and thermal properties. These features make carbon nanomaterials especially interesting for next-generation memory and storage devices, such as resistive random access memory, phase-change memory, spin-transfer-torque magnetic random access memory and ferroelectric random access memory. Non-volatile memories greatly benefit from the use of carbon nanomaterials in terms of bit density and energy efficiency. In this Review, we discuss sp2-hybridized carbon-based low-dimensional nanostructures, such as fullerene, carbon nanotubes and graphene, in the context of non-volatile memory devices and architectures. Applications of carbon nanomaterials as memory electrodes, interfacial engineering layers, resistive-switching media, and scalable, high-performance memory selectors are investigated. Finally, we compare the different memory technologies in terms of writing energy and time, and highlight major challenges in the manufacturing, integration and understanding of the physical mechanisms and material properties.

  17. Strain-controlled nonvolatile magnetization switching

    Science.gov (United States)

    Geprägs, S.; Brandlmaier, A.; Brandt, M. S.; Gross, R.; Goennenwein, S. T. B.

    2014-11-01

    We investigate different approaches towards a nonvolatile switching of the remanent magnetization in single-crystalline ferromagnets at room temperature via elastic strain using ferromagnetic thin film/piezoelectric actuator hybrids. The piezoelectric actuator induces a voltage-controllable strain along different crystalline directions of the ferromagnetic thin film, resulting in modifications of its magnetization by converse magnetoelastic effects. We quantify the magnetization changes in the hybrids via ferromagnetic resonance spectroscopy and superconducting quantum interference device magnetometry. These measurements demonstrate a significant strain-induced change of the magnetization, limited by an inefficient strain transfer and domain formation in the particular system studied. To overcome these obstacles, we address practicable engineering concepts and use a model to demonstrate that a strain-controlled, nonvolatile magnetization switching should be possible in appropriately engineered ferromagnetic/piezoelectric actuator hybrids.

  18. Flexible graphene–PZT ferroelectric nonvolatile memory

    International Nuclear Information System (INIS)

    Lee, Wonho; Ahn, Jong-Hyun; Kahya, Orhan; Toh, Chee Tat; Özyilmaz, Barbaros

    2013-01-01

    We report the fabrication of a flexible graphene-based nonvolatile memory device using Pb(Zr 0.35 ,Ti 0.65 )O 3 (PZT) as the ferroelectric material. The graphene and PZT ferroelectric layers were deposited using chemical vapor deposition and sol–gel methods, respectively. Such PZT films show a high remnant polarization (P r ) of 30 μC cm −2 and a coercive voltage (V c ) of 3.5 V under a voltage loop over ±11 V. The graphene–PZT ferroelectric nonvolatile memory on a plastic substrate displayed an on/off current ratio of 6.7, a memory window of 6 V and reliable operation. In addition, the device showed one order of magnitude lower operation voltage range than organic-based ferroelectric nonvolatile memory after removing the anti-ferroelectric behavior incorporating an electrolyte solution. The devices showed robust operation in bent states of bending radii up to 9 mm and in cycling tests of 200 times. The devices exhibited remarkable mechanical properties and were readily integrated with plastic substrates for the production of flexible circuits. (paper)

  19. Flexible graphene-PZT ferroelectric nonvolatile memory.

    Science.gov (United States)

    Lee, Wonho; Kahya, Orhan; Toh, Chee Tat; Ozyilmaz, Barbaros; Ahn, Jong-Hyun

    2013-11-29

    We report the fabrication of a flexible graphene-based nonvolatile memory device using Pb(Zr0.35,Ti0.65)O3 (PZT) as the ferroelectric material. The graphene and PZT ferroelectric layers were deposited using chemical vapor deposition and sol–gel methods, respectively. Such PZT films show a high remnant polarization (Pr) of 30 μC cm−2 and a coercive voltage (Vc) of 3.5 V under a voltage loop over ±11 V. The graphene–PZT ferroelectric nonvolatile memory on a plastic substrate displayed an on/off current ratio of 6.7, a memory window of 6 V and reliable operation. In addition, the device showed one order of magnitude lower operation voltage range than organic-based ferroelectric nonvolatile memory after removing the anti-ferroelectric behavior incorporating an electrolyte solution. The devices showed robust operation in bent states of bending radii up to 9 mm and in cycling tests of 200 times. The devices exhibited remarkable mechanical properties and were readily integrated with plastic substrates for the production of flexible circuits.

  20. Transition-Edge Hot-Electron Microbolometers for Millimeter and Submillimeter Astrophysics

    Science.gov (United States)

    Hsieh, Wen-Ting; Stevenson, Thomas; U-yen, Kongpop; Wollack, Edward; Barrentine, Emily

    2014-01-01

    The millimeter and the submillimeter wavelengths of the electromagnetic spectrum hold a wealth of information about the evolution of the universe. In particular, cosmic microwave background (CMB) radiation and its polarization carry the oldest information in the universe, and provide the best test of the inflationary paradigm available to astronomy today. Detecting gravity waves through their imprint on the CMB polarization would have extraordinary repercussions for cosmology and physics. A transition-edge hot-electron micro - bolometer (THM) consists of a superconducting bilayer transition-edge sensor (TES) with a thin-film absorber. Unlike traditional monolithic bolometers that make use of micromachined structures, the THM em ploys the decoupling between electrons and phonons at millikelvin temperatures to provide thermal isolation. The devices are fabricated photolithographically and are easily integrated with antennas via microstrip transmission lines, and with SQUID (superconducting quantum interference device) readouts. The small volume of the absorber and TES produces a short thermal time constant that facilitates rapid sky scanning. The THM consists of a thin-film metal absorber overlapping a superconducting TES. The absorber forms the termination of a superconducting microstripline that carries RF power from an antenna. The purpose of forming a separate absorber and TES is to allow flexibility in the optimization of the two components. In particular, the absorbing film's impedance can be chosen to match the antenna, while the TES impedance can be chosen to match to the readout SQUID amplifier. This scheme combines the advantages of the TES with the advantages of planar millimeter-wave transmission line circuits. Antenna-coupling to the detectors via planar transmission lines allows the detector dimensions to be much smaller than a wavelength, so the technique can be extended across the entire microwave, millimeter, and submillimeter wavelength ranges. The

  1. Radiation-hardened nonvolatile MNOS RAM

    International Nuclear Information System (INIS)

    Wrobel, T.F.; Dodson, W.H.; Hash, G.L.; Jones, R.V.; Nasby, R.D.; Olson, R.J.

    1983-01-01

    A radiation hardened nonvolatile MNOS RAM is being developed at Sandia National Laboratories. The memory organization is 128 x 8 bits and utilizes two p-channel MNOS transistors per memory cell. The peripheral circuitry is constructed with CMOS metal gate and is processed with standard Sandia rad-hard processing techniques. The devices have memory retention after a dose-rate exposure of 1E12 rad(Si)/s, are functional after total dose exposure of 1E6 rad(Si), and are dose-rate upset resistant to levels of 7E8 rad(Si)/s

  2. Proximity effect and hot-electron diffusion in Ag/Al2O3/Al tunnel junctions

    International Nuclear Information System (INIS)

    Netel, H.; Jochum, J.; Labov, S.E.; Mears, C.A.; Frank, M.; Chow, D.; Lindeman, M.A.; Hiller, L.J.

    1997-01-01

    We have fabricated Ag/Al 2 O 3 /Al tunnel junctions on Si substrates using a new process. This process was developed to fabricate superconducting tunnel junctions (STJs) on the surface of a superconductor. These junctions allow us to study the proximity effect of a superconducting Al film on a normal metal trapping layer. In addition, these devices allow us to measure the hot-electron diffusion constant using a single junction. Lastly these devices will help us optimize the design and fabrication of tunnel junctions on the surface of high-Z, ultra-pure superconducting crystals. 5 refs., 8 figs

  3. Phase-locking of a terahertz solid-state source using a superconducting hot-electron bolometer mixer

    International Nuclear Information System (INIS)

    Miao, W; Zhang, W; Zhou, K M; Li, S L; Zhang, K; Duan, W Y; Yao, Q J; Shi, S C

    2013-01-01

    We report on a scheme whereby the local-oscillator (LO) of a THz heterodyne receiver can be phase-locked by the mixer of the heterodyne receiver. This scheme is demonstrated for the phase-locking of an 847.6 GHz Gunn oscillator and multiplier chain combined source with a superconducting hot-electron bolometer (HEB) mixer. We show that with this technique the phase-locked beat signal can reach a signal-to-noise ratio higher than 70 dB in a resolution bandwidth (RBW) of 1 Hz. This phase-locking scheme should find good use in THz heterodyne spectrometers. (paper)

  4. Design of nanophotonic, hot-electron solar-blind ultraviolet detectors with a metal-oxide-semiconductor structure

    International Nuclear Information System (INIS)

    Wang, Zhiyuan; Wang, Xiaoxin; Liu, Jifeng

    2014-01-01

    Solar-blind ultraviolet (UV) detection refers to photon detection specifically in the wavelength range of 200 nm–320 nm. Without background noises from solar radiation, it has broad applications from homeland security to environmental monitoring. The most commonly used solid state devices for this application are wide band gap (WBG) semiconductor photodetectors (Eg > 3.5 eV). However, WBG semiconductors are difficult to grow and integrate with Si readout integrated circuits (ROICs). In this paper, we design a nanophotonic metal-oxide-semiconductor structure on Si for solar-blind UV detectors. Instead of using semiconductors as the active absorber, we use Sn nano-grating structures to absorb UV photons and generate hot electrons for internal photoemission across the Sn/SiO 2 interfacial barrier, thereby generating photocurrent between the metal and the n-type Si region upon UV excitation. Moreover, the transported hot electron has an excess kinetic energy >3 eV, large enough to induce impact ionization and generate another free electron in the conduction band of n-Si. This process doubles the quantum efficiency. On the other hand, the large metal/oxide interfacial energy barrier (>3.5 eV) also enables solar-blind UV detection by blocking the less energetic electrons excited by visible photons. With optimized design, ∼75% UV absorption and hot electron excitation can be achieved within the mean free path of ∼20 nm from the metal/oxide interface. This feature greatly enhances hot electron transport across the interfacial barrier to generate photocurrent. The simple geometry of the Sn nano-gratings and the MOS structure make it easy to fabricate and integrate with Si ROICs compared to existing solar-blind UV detection schemes. The presented device structure also breaks through the conventional notion that photon absorption by metal is always a loss in solid-state photodetectors, and it can potentially be extended to other active metal photonic devices. (paper)

  5. Nonlinear electron-acoustic rogue waves in electron-beam plasma system with non-thermal hot electrons

    Science.gov (United States)

    Elwakil, S. A.; El-hanbaly, A. M.; Elgarayh, A.; El-Shewy, E. K.; Kassem, A. I.

    2014-11-01

    The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, non-thermal hot electrons obeying a non-thermal distribution, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles on the electron beam and energetic population parameter are discussed. The results of the present investigation may be applicable in auroral zone plasma.

  6. Ion acoustic solitons and supersolitons in a magnetized plasma with nonthermal hot electrons and Boltzmann cool electrons

    Energy Technology Data Exchange (ETDEWEB)

    Rufai, O. R., E-mail: rajirufai@gmail.com; Bharuthram, R., E-mail: rbharuthram@uwc.ac.za [University of the Western Cape, Belville (South Africa); Singh, S. V., E-mail: satyavir@iigs.iigm.res.in; Lakhina, G. S., E-mail: lakhina@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel (W), Navi Mumbai (India)

    2014-08-15

    Arbitrary amplitude, ion acoustic solitons, and supersolitons are studied in a magnetized plasma with two distinct groups of electrons at different temperatures. The plasma consists of a cold ion fluid, cool Boltzmann electrons, and nonthermal energetic hot electrons. Using the Sagdeev pseudo-potential technique, the effect of nonthermal hot electrons on soliton structures with other plasma parameters is studied. Our numerical computation shows that negative potential ion-acoustic solitons and double layers can exist both in the subsonic and supersonic Mach number regimes, unlike the case of an unmagnetized plasma where they can only exist in the supersonic Mach number regime. For the first time, it is reported here that in addition to solitions and double layers, the ion-acoustic supersoliton solutions are also obtained for certain range of parameters in a magnetized three-component plasma model. The results show good agreement with Viking satellite observations of the solitary structures with density depletions in the auroral region of the Earth's magnetosphere.

  7. All-inorganic perovskite nanocrystal assisted extraction of hot electrons and biexcitons from photoexcited CdTe quantum dots.

    Science.gov (United States)

    Mondal, Navendu; De, Apurba; Samanta, Anunay

    2018-01-03

    Excitation of semiconductor quantum dots (QDs) by photons possessing energy higher than the band-gap creates a hot electron-hole pair, which releases its excess energy as waste heat or under certain conditions (when hν > 2E g ) produces multiple excitons. Extraction of these hot carriers and multiple excitons is one of the key strategies for enhancing the efficiency of QD-based photovoltaic devices. However, this is a difficult task as competing carrier cooling and relaxation of multiple excitons (through Auger recombination) are ultrafast processes. Herein, we study the potential of all-inorganic perovskite nanocrystals (NCs) of CsPbX 3 (X = Cl, Br) as harvesters of these short-lived species from photo-excited CdTe QDs. The femtosecond transient absorption measurements show CsPbX 3 mediated extraction of both hot and thermalized electrons of the QDs (under a low pump power) and (under a high pump fluence) extraction of multiple excitons prior to their Auger assisted recombination. A faster timescale of thermalized electron transfer (∼2 ps) and a higher extraction efficiency of hot electrons (∼60%) are observed in the presence of CsPbBr 3 . These observations demonstrate the potential of all-inorganic perovskite NCs in the extraction of these short-lived energy rich species implying that complexes of the QDs and perovskite NCs are better suited for improving the efficiency of QD-sensitized solar cells.

  8. Overview of emerging nonvolatile memory technologies.

    Science.gov (United States)

    Meena, Jagan Singh; Sze, Simon Min; Chand, Umesh; Tseng, Tseung-Yuen

    2014-01-01

    Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new

  9. Overview of emerging nonvolatile memory technologies

    Science.gov (United States)

    2014-01-01

    Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new

  10. Micron-scale mapping of megagauss magnetic fields using optical polarimetry to probe hot electron transport in petawatt-class laser-solid interactions.

    Science.gov (United States)

    Chatterjee, Gourab; Singh, Prashant Kumar; Robinson, A P L; Blackman, D; Booth, N; Culfa, O; Dance, R J; Gizzi, L A; Gray, R J; Green, J S; Koester, P; Kumar, G Ravindra; Labate, L; Lad, Amit D; Lancaster, K L; Pasley, J; Woolsey, N C; Rajeev, P P

    2017-08-21

    The transport of hot, relativistic electrons produced by the interaction of an intense petawatt laser pulse with a solid has garnered interest due to its potential application in the development of innovative x-ray sources and ion-acceleration schemes. We report on spatially and temporally resolved measurements of megagauss magnetic fields at the rear of a 50-μm thick plastic target, irradiated by a multi-picosecond petawatt laser pulse at an incident intensity of ~10 20 W/cm 2 . The pump-probe polarimetric measurements with micron-scale spatial resolution reveal the dynamics of the magnetic fields generated by the hot electron distribution at the target rear. An annular magnetic field profile was observed ~5 ps after the interaction, indicating a relatively smooth hot electron distribution at the rear-side of the plastic target. This is contrary to previous time-integrated measurements, which infer that such targets will produce highly structured hot electron transport. We measured large-scale filamentation of the hot electron distribution at the target rear only at later time-scales of ~10 ps, resulting in a commensurate large-scale filamentation of the magnetic field profile. Three-dimensional hybrid simulations corroborate our experimental observations and demonstrate a beam-like hot electron transport at initial time-scales that may be attributed to the local resistivity profile at the target rear.

  11. Models for Total-Dose Radiation Effects in Non-Volatile Memory

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Philip Montgomery; Wix, Steven D.

    2017-04-01

    The objective of this work is to develop models to predict radiation effects in non- volatile memory: flash memory and ferroelectric RAM. In flash memory experiments have found that the internal high-voltage generators (charge pumps) are the most sensitive to radiation damage. Models are presented for radiation effects in charge pumps that demonstrate the experimental results. Floating gate models are developed for the memory cell in two types of flash memory devices by Intel and Samsung. These models utilize Fowler-Nordheim tunneling and hot electron injection to charge and erase the floating gate. Erase times are calculated from the models and compared with experimental results for different radiation doses. FRAM is less sensitive to radiation than flash memory, but measurements show that above 100 Krad FRAM suffers from a large increase in leakage current. A model for this effect is developed which compares closely with the measurements.

  12. Radiation evaluation of commercial ferroelectric nonvolatile memories

    International Nuclear Information System (INIS)

    Benedetto, J.M.; DeLancey, W.M.; Oldham, T.R.; McGarrity, J.M.; Tipton, C.W.; Brassington, M.; Fisch, D.E.

    1991-01-01

    This paper reports on ferroelectric (FE) on complementary metal-oxide semiconductor (CMOS) 4-kbit nonvolatile memories, 8-bit octal latches (with and without FE), and process control test chips that were used to establish a baseline characterization of the radiation response of CMOS/FE integrated devices and to determine whether the additional FE processing caused significant degradation to the baseline CMOS process. Functional failure of all 4-kbit memories and octal latches occurred at total doses of between 2 and 4 krad(Si), most likely due to field- oxide effects in the underlying CMOS. No significant difference was observed between the radiation responses of devices with and without the FE film in this commercial process

  13. A radiation-tolerant, low-power non-volatile memory based on silicon nanocrystal quantum dots

    OpenAIRE

    Bell, L. D.; Boer, E.; Ostraat, M.; Brongersma, M. L.; Flagan, R. C.; Atwater, H. A.; De Blauwe, J.; Green, M. L.

    2001-01-01

    Nanocrystal nonvolatile floating-gate memories are a good candidate for space applications - initial results suggest they are fast, more reliable and consume less power than conventional floating gate memories. In the nanocrystal based NVM device, charge is not stored on a continuous polysilicon layer (so-called floating gate), but instead on a layer of discrete nanocrystals. Charge injection and storage in dense arrays of silicon nanocrystals in SiO_2 is a critical aspect of the performance ...

  14. Study of nonlinear electron-acoustic solitary and shock waves in a dissipative, nonplanar space plasma with superthermal hot electrons

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jiu-Ning, E-mail: hanjiuning@126.com; He, Yong-Lin; Luo, Jun-Hua; Nan, Ya-Gong; Han, Zhen-Hai; Dong, Guang-Xing [College of Physics and Electromechanical Engineering, Hexi University, Zhangye 734000 (China); Duan, Wen-Shan [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Li, Jun-Xiu [College of Civil Engineering, Hexi University, Zhangye 734000 (China)

    2014-01-15

    With the consideration of the superthermal electron distribution, we present a theoretical investigation about the nonlinear propagation of electron-acoustic solitary and shock waves in a dissipative, nonplanar non-Maxwellian plasma comprised of cold electrons, superthermal hot electrons, and stationary ions. The reductive perturbation technique is used to obtain a modified Korteweg-de Vries Burgers equation for nonlinear waves in this plasma. We discuss the effects of various plasma parameters on the time evolution of nonplanar solitary waves, the profile of shock waves, and the nonlinear structure induced by the collision between planar solitary waves. It is found that these parameters have significant effects on the properties of nonlinear waves and collision-induced nonlinear structure.

  15. Two-photon-induced hot-electron transfer to a single molecule in a scanning tunneling microscope

    International Nuclear Information System (INIS)

    Wu, S. W.; Ho, W.

    2010-01-01

    The junction of a scanning tunneling microscope (STM) operating in the tunneling regime was irradiated with femtosecond laser pulses. A photoexcited hot electron in the STM tip resonantly tunnels into an excited state of a single molecule on the surface, converting it from the neutral to the anion. The electron-transfer rate depends quadratically on the incident laser power, suggesting a two-photon excitation process. This nonlinear optical process is further confirmed by the polarization measurement. Spatial dependence of the electron-transfer rate exhibits atomic-scale variations. A two-pulse correlation experiment reveals the ultrafast dynamic nature of photoinduced charging process in the STM junction. Results from these experiments are important for understanding photoinduced interfacial charge transfer in many nanoscale inorganic-organic structures.

  16. Electron - polar acoustical phonon interactions in nitride based diluted magnetic semiconductor quantum well via hot electron magnetotransport

    International Nuclear Information System (INIS)

    Pandya, Ankur; Shinde, Satyam; Jha, Prafulla K.

    2015-01-01

    In this paper the hot electron transport properties like carrier energy and momentum scattering rates and electron energy loss rates are calculated via interactions of electrons with polar acoustical phonons for Mn doped BN quantum well in BN nanosheets via piezoelectric scattering and deformation potential mechanisms at low temperatures with high electric field. Electron energy loss rate increases with the electric field. It is observed that at low temperatures and for low electric field the phonon absorption is taking place whereas, for sufficient large electric field, phonon emission takes place. Under the piezoelectric (polar acoustical phonon) scattering mechanism, the carrier scattering rate decreases with the reduction of electric field at low temperatures wherein, the scattering rate variation with electric field is limited by a specific temperature beyond which there is no any impact of electric field on such scattering

  17. HESTER: a hot-electron superconducting tokamak experimental reactor at M.I.T

    International Nuclear Information System (INIS)

    Schultz, J.H.; Montgomery, D.B.

    1983-04-01

    HESTER is an experimental tokamak, designed to resolve many of the central questions in the tokamak development program in the 1980's. It combines several unique features with new perspectives on the other major tokamak experiments scheduled for the next decade. The overall objectives of HESTER, in rough order of their presently perceived importance, are the achievement of reactor-like wall-loadings and plasma parameters for long pulse periods, determination of a good, reactor-relevant method of steady-state or very long pulse tokamak current drive, duplication of the planned very high temperature neutral injection experiments using only radio frequency heating, a demonstration of true steady-state tokamak operation, integration of a high-performance superconducting magnet system into a tokamak experiment, determination of the best methods of long term impurity control, and studies of transport and pressure limits in high field, high aspect ratio tokamak plasmas. These objectives are described

  18. Nonvolatile Memory Materials for Neuromorphic Intelligent Machines.

    Science.gov (United States)

    Jeong, Doo Seok; Hwang, Cheol Seong

    2018-04-18

    Recent progress in deep learning extends the capability of artificial intelligence to various practical tasks, making the deep neural network (DNN) an extremely versatile hypothesis. While such DNN is virtually built on contemporary data centers of the von Neumann architecture, physical (in part) DNN of non-von Neumann architecture, also known as neuromorphic computing, can remarkably improve learning and inference efficiency. Particularly, resistance-based nonvolatile random access memory (NVRAM) highlights its handy and efficient application to the multiply-accumulate (MAC) operation in an analog manner. Here, an overview is given of the available types of resistance-based NVRAMs and their technological maturity from the material- and device-points of view. Examples within the strategy are subsequently addressed in comparison with their benchmarks (virtual DNN in deep learning). A spiking neural network (SNN) is another type of neural network that is more biologically plausible than the DNN. The successful incorporation of resistance-based NVRAM in SNN-based neuromorphic computing offers an efficient solution to the MAC operation and spike timing-based learning in nature. This strategy is exemplified from a material perspective. Intelligent machines are categorized according to their architecture and learning type. Also, the functionality and usefulness of NVRAM-based neuromorphic computing are addressed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Distinguishing of Ile/Leu amino acid residues in the PP3 protein by (hot) electron capture dissociation in Fourier transform ion cyclotron resonance mass spectrometry

    DEFF Research Database (Denmark)

    Kjeldsen, Frank; Haselmann, Kim F; Sørensen, Esben Skipper

    2003-01-01

    In hot electron capture dissociation (HECD), multiply protonated polypeptides fragment upon capturing approximately 11-eV electrons. The excess of energy upon the primary c, z* cleavage induces secondary fragmentation in z* fragments. The resultant w ions allow one to distinguish between the isom...

  20. Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

    2014-11-15

    In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ∼300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub β}). The detectors impulse response function was measured in situ on NIF short-pulse (∼90 ps) experiments, and in off-line tests.

  1. Lateral terahertz hot-electron bolometer based on an array of Sn nanothreads in GaAs

    Science.gov (United States)

    Ponomarev, D. S.; Lavrukhin, D. V.; Yachmenev, A. E.; Khabibullin, R. A.; Semenikhin, I. E.; Vyurkov, V. V.; Ryzhii, M.; Otsuji, T.; Ryzhii, V.

    2018-04-01

    We report on the proposal and the theoretical and experimental studies of the terahertz hot-electron bolometer (THz HEB) based on a gated GaAs structure like the field-effect transistor with the array of parallel Sn nanothreads (Sn-NTs). The operation of the HEB is associated with an increase in the density of the delocalized electrons due to their heating by the incoming THz radiation. The quantum and the classical device models were developed, the quantum one was based on the self-consistent solution of the Poisson and Schrödinger equations, the classical model involved the Poisson equation and density of states omitting quantization. We calculated the electron energy distributions in the channels formed around the Sn-NTs for different gate voltages and found the fraction of the delocalized electrons propagating across the energy barriers between the NTs. Since the fraction of the delocalized electrons strongly depends on the average electron energy (effective temperature), the proposed THz HEB can exhibit an elevated responsivity compared with the HEBs based on more standard heterostructures. Due to a substantial anisotropy of the device structure, the THz HEB may demonstrate a noticeable polarization selectivity of the response to the in-plane polarized THz radiation. The features of the THz HEB might be useful in their practical applications in biology, medicine and material science.

  2. Trapping in GaN-based metal-insulator-semiconductor transistors: Role of high drain bias and hot electrons

    Energy Technology Data Exchange (ETDEWEB)

    Meneghini, M., E-mail: matteo.meneghini@dei.unipd.it; Bisi, D.; Meneghesso, G.; Zanoni, E. [Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova (Italy); Marcon, D.; Stoffels, S.; Van Hove, M.; Wu, T.-L.; Decoutere, S. [IMEC, Kapeldreef 75, 3001 Heverlee (Belgium)

    2014-04-07

    This paper describes an extensive analysis of the role of off-state and semi-on state bias in inducing the trapping in GaN-based power High Electron Mobility Transistors. The study is based on combined pulsed characterization and on-resistance transient measurements. We demonstrate that—by changing the quiescent bias point from the off-state to the semi-on state—it is possible to separately analyze two relevant trapping mechanisms: (i) the trapping of electrons in the gate-drain access region, activated by the exposure to high drain bias in the off-state; (ii) the trapping of hot-electrons within the AlGaN barrier or the gate insulator, which occurs when the devices are operated in the semi-on state. The dependence of these two mechanisms on the bias conditions and on temperature, and the properties (activation energy and cross section) of the related traps are described in the text.

  3. Study of field induced hot-electron emission using the composite microemitters with varying dielectric layer thickness

    International Nuclear Information System (INIS)

    Mousa, M.S.

    1987-07-01

    The analysis of the measurements obtained from the of field emission of electrons from composite metal-insulator (M-I) micropoint cathodes, using the combination of a high resolution electron spectrometer and a field emission microscope, has been presented. Results obtained describe the reversible current-voltage characteristic, emission images and electron energy distribution measurements of both thin and the optimum thick coatings. The observed effects, e.g. the threshold switch-on phenomena and the field-dependence of the F.W.H.M. and energy shift of the electron spectra have been identified in terms of a field-induced hot-electron emission (FIHEE) mechanism resulting from field penetration in the insulating film where conducting channels are formed. The theoretical implications accounts for the channels field intensification mechanism and the conduction properties with applied field, and the F.W.H.M. dependence on electron temperature. The control of the emission process at low fields by the M-I contact junction and at high fields by the bulk properties of the insulator have also been accounted for. These experimental and theoretical findings have been shown to be consistent with recently published data on M-I microstructures on broad-area (BA) high-voltage electrodes. (author). 18 refs, 6 figs

  4. Equivalent circuit-level model of quantum cascade lasers with integrated hot-electron and hot-phonon effects

    Science.gov (United States)

    Yousefvand, H. R.

    2017-12-01

    We report a study of the effects of hot-electron and hot-phonon dynamics on the output characteristics of quantum cascade lasers (QCLs) using an equivalent circuit-level model. The model is developed from the energy balance equation to adopt the electron temperature in the active region levels, the heat transfer equation to include the lattice temperature, the nonequilibrium phonon rate to account for the hot phonon dynamics and simplified two-level rate equations to incorporate the carrier and photon dynamics in the active region. This technique simplifies the description of the electron-phonon interaction in QCLs far from the equilibrium condition. Using the presented model, the steady and transient responses of the QCLs for a wide range of sink temperatures (80 to 320 K) are investigated and analysed. The model enables us to explain the operating characteristics found in QCLs. This predictive model is expected to be applicable to all QCL material systems operating in pulsed and cw regimes.

  5. Design of all-optical, hot-electron current-direction-switching device based on geometrical asymmetry.

    Science.gov (United States)

    Kumarasinghe, Chathurangi S; Premaratne, Malin; Gunapala, Sarath D; Agrawal, Govind P

    2016-02-18

    We propose a nano-scale current-direction-switching device(CDSD) that operates based on the novel phenomenon of geometrical asymmetry between two hot-electron generating plasmonic nanostructures. The proposed device is easy to fabricate and economical to develop compared to most other existing designs. It also has the ability to function without external wiring in nano or molecular circuitry since it is powered and controlled optically. We consider a such CDSD made of two dissimilar nanorods separated by a thin but finite potential barrier and theoretically derive the frequency-dependent electron/current flow rate. Our analysis takes in to account the quantum dynamics of electrons inside the nanorods under a periodic optical perturbation that are confined by nanorod boundaries, modelled as finite cylindrical potential wells. The influence of design parameters, such as geometric difference between the two nanorods, their volumes and the barrier width on quality parameters such as frequency-sensitivity of the current flow direction, magnitude of the current flow, positive to negative current ratio, and the energy conversion efficiency is discussed by considering a device made of Ag/TiO2/Ag. Theoretical insight and design guidelines presented here are useful for customizing our proposed CDSD for applications such as self-powered logic gates, power supplies, and sensors.

  6. Immunoassay of C-reactive protein by hot electron induced electrochemiluminescence using integrated electrodes with hydrophobic sample confinement

    Energy Technology Data Exchange (ETDEWEB)

    Ylinen-Hinkka, T., E-mail: tiina.ylinen-hinkka@aalto.fi [Laboratory of Analytical Chemistry, Aalto University School of Chemical Technology, P.O. Box 16100, FI-00076 Aalto (Finland); Niskanen, A.J.; Franssila, S. [Department of Materials Science and Engineering, Aalto University School of Chemical Technology, P.O. Box 16200, FI-00076 Aalto (Finland); Kulmala, S. [Laboratory of Analytical Chemistry, Aalto University School of Chemical Technology, P.O. Box 16100, FI-00076 Aalto (Finland)

    2011-09-19

    Highlights: {center_dot} C-reactive protein has been determined in the concentration range 0.01-10 mg L{sup -1} using an electrochemiluminescence microchip which employs integrated electrodes with hydrophobic sample confinement. {center_dot} This arrangement enables very simple and fast CRP analysis amenable to point-of-care applications. - Abstract: C-reactive protein (CRP) was determined in the concentration range 0.01-10 mg L{sup -1} using hot electron induced electrochemiluminescence (HECL) with devices combining both working and counter electrodes and sample confinement on a single chip. The sample area on the electrodes was defined by a hydrophobic ring, which enabled dispensing the reagents and the analyte directly on the electrode. Immunoassay of CRP by HECL using integrated electrodes is a good candidate for a high-sensitivity point-of-care CRP-test, because the concentration range is suitable, miniaturisation of the measurement system has been demonstrated and the assay method with integrated electrodes is easy to use. High-sensitivity CRP tests can be used to monitor the current state of cardiovascular disease and also to predict future cardiovascular problems in apparently healthy people.

  7. Identification of nonvolatile compounds in clove (Syzygium aromaticum) from Manado

    Science.gov (United States)

    Fathoni, A.; Saepudin, E.; Cahyana, A. H.; Rahayu, D. U. C.; Haib, J.

    2017-07-01

    Syzygium aromaticum (clove) are native to Indonesia and have been widely used in food industry due to their flavor. Nonvolatile compounds contribute to flavor, mainly in their taste. Currently, there is very little information available about nonvolatile compounds in clove. Identification of nonvolatile compounds is important to improve clove's value. Compound extraction was conducted by maceration in ethanol. Fractionations of the extract were performed by using gravity column chromatography on silica gel and Sephadex LH-20 as stationary phase. Nonvolatile compounds were identified by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). LC-MS/MS was operated in negative mode with 0.1 % formic acid in water and acetonitrile as mobile phase. Nonvolatile compounds were identified by fragment analysis and compared to references. Several compounds had been identified and characterized asquinic acid, monogalloylglucose, gallic acid, digalloylglucose, isobiflorin, biflorin, ellagic acid, hydroxygallic acid, luteolin, quercetin, naringenin, kaempferol, isorhamnetin, dimethoxyluteolin, and rhamnetin. These compounds had two main flavor perceptions, i.e. astringent, and bitter.

  8. Nonvolatile resistive switching in Pt/laALO3/srTiO3 heterostructures

    KAUST Repository

    Wu, S.; Luo, X.; Turner, S.; Peng, H.; Lin, W.; Ding, J.; David, A.; Wang, B.; Van, Tendeloo, G.; Wang, J.; Wu, Tao

    2013-01-01

    Resistive switching heterojunctions, which are promising for nonvolatile memory applications, usually share a capacitorlike metal-oxide-metal configuration. Here, we report on the nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures

  9. Nonvolatile memory design magnetic, resistive, and phase change

    CERN Document Server

    Li, Hai

    2011-01-01

    The manufacture of flash memory, which is the dominant nonvolatile memory technology, is facing severe technical barriers. So much so, that some emerging technologies have been proposed as alternatives to flash memory in the nano-regime. Nonvolatile Memory Design: Magnetic, Resistive, and Phase Changing introduces three promising candidates: phase-change memory, magnetic random access memory, and resistive random access memory. The text illustrates the fundamental storage mechanism of these technologies and examines their differences from flash memory techniques. Based on the latest advances,

  10. Ferroelectric memories: A possible answer to the hardened nonvolatile question

    International Nuclear Information System (INIS)

    Messenger, G.C.; Coppage, F.N.

    1988-01-01

    Ferroelectric memory cells have been fabricated using a process compatible with semiconductor VLSI (Very Large-Scale Integration) manufacturing techniques which are basically nonvolatile and radiation hard. The memory can be made NDRO (Nondestructive Readout) for strategic systems using several techniques; the most practical is probably a rapid read/restore in combination with EDAC software. This memory can replace plated wire and will have substantial advantages in cost, weight, size, power and speed. It provides a practical cost-competitive solution to the need for nonvolatile RAM in all hardened tactical, avionic, and space systems

  11. Utilizing hot electrons

    Energy Technology Data Exchange (ETDEWEB)

    Nozik, Arthur J.

    2018-03-01

    In current solar cells, any photon energy exceeding the semiconductor bandgap is lost before being collected, limiting the cell performance. Hot carrier solar cells could avoid these losses. Now, a detailed experimental study and analysis shows that this strategy could lead to an improvement of the photoconversion efficiency in practice.

  12. Quasilinear dynamics of a cloud of hot electrons propagating through a plasma with decreasing density and temperature

    International Nuclear Information System (INIS)

    Foroutan, G.; Khalilpour, H.; Moslehi-Fard, M.; Li, B.; Robinson, P. A.

    2008-01-01

    The effects of plasma inhomogeneities on the propagation of a cloud of hot electrons through a cold background plasma and generation of Langmuir waves are investigated using numerical simulations of the quasilinear equations. It is found that in a plasma with decreasing density the quasilinear relaxation of the electron distribution in velocity space is accelerated and the levels of the generated Langmuir waves are enhanced. The magnitude of the induced emission rate is increased and its maximum value moves to lower velocities. Due to density gradient the height of plateau shows an increase at small distances and a corresponding decrease at large distances. It is also found that in a plasma with decreasing temperature, the relaxation of the beam is retarded, the spectral density of Langmuir waves is broadened, and the height of the plateau decreases below its value in a uniform plasma. In the presence of both density and temperature gradients, at given position, the height and upper boundary of the plateau and the level of Langmuir waves are all increased at small velocities. The spatial expansion of the beam is increased by the plasma inhomogeneities, but its average velocity of propagation decreases. Initially, at a given position, the velocity at the upper boundary of the plateau is smaller in the presence of the density gradient than in the uniform plasma but the reverse is true at longer times. Due to temperature gradient, at large times and small distances, the upper boundary of the plateau is increased above its value in the uniform plasma. Because of fast relaxation, the value of the lower boundary of the plateau in the plasma with decreasing density is always less than its value in the uniform plasma. It is found that the local velocity of the beam decreases when the density gradient is present. The local velocity spread of the beam remains unchanged during the propagation of the beam in the uniform plasma, but increases in the presence of inhomogeneities.

  13. Energy relaxation and separation of a hot electron-hole pair in organic aggregates from a time-dependent wavepacket diffusion method

    International Nuclear Information System (INIS)

    Han, Lu; Liang, WanZhen; Zhao, Yi; Zhong, Xinxin

    2014-01-01

    The time-dependent wavepacket diffusive method [X. Zhong and Y. Zhao, J. Chem. Phys. 138, 014111 (2013)] is extended to investigate the energy relaxation and separation of a hot electron-hole pair in organic aggregates with incorporation of Coulomb interaction and electron-phonon coupling. The pair initial condition generated by laser pulse is represented by a Gaussian wavepacket with a central momentum. The results reveal that the hot electron energy relaxation is very well described by two rate processes with the fast rate much larger than the slow one, consistent with experimental observations, and an efficient electron-hole separation is accomplished accompanying the fast energy relaxation. Furthermore, although the extra energy indeed helps the separation by overcoming the Coulomb interaction, the width of initial wavepacket is much sensitive to the separation efficiency and the narrower wavepacket generates the more separated charges. This behavior may be useful to understand the experimental controversy of the hot carrier effect on charge separation

  14. EDITORIAL: Non-volatile memory based on nanostructures Non-volatile memory based on nanostructures

    Science.gov (United States)

    Kalinin, Sergei; Yang, J. Joshua; Demming, Anna

    2011-06-01

    Non-volatile memory refers to the crucial ability of computers to store information once the power source has been removed. Traditionally this has been achieved through flash, magnetic computer storage and optical discs, and in the case of very early computers paper tape and punched cards. While computers have advanced considerably from paper and punched card memory devices, there are still limits to current non-volatile memory devices that restrict them to use as secondary storage from which data must be loaded and carefully saved when power is shut off. Denser, faster, low-energy non-volatile memory is highly desired and nanostructures are the critical enabler. This special issue on non-volatile memory based on nanostructures describes some of the new physics and technology that may revolutionise future computers. Phase change random access memory, which exploits the reversible phase change between crystalline and amorphous states, also holds potential for future memory devices. The chalcogenide Ge2Sb2Te5 (GST) is a promising material in this field because it combines a high activation energy for crystallization and a relatively low crystallization temperature, as well as a low melting temperature and low conductivity, which accommodates localized heating. Doping is often used to lower the current required to activate the phase change or 'reset' GST but this often aggravates other problems. Now researchers in Korea report in-depth studies of SiO2-doped GST and identify ways of optimising the material's properties for phase-change random access memory [1]. Resistance switching is an area that has attracted a particularly high level of interest for non-volatile memory technology, and a great deal of research has focused on the potential of TiO2 as a model system in this respect. Researchers at HP labs in the US have made notable progress in this field, and among the work reported in this special issue they describe means to control the switch resistance and show

  15. Hard x-ray (>100 keV) imager to measure hot electron preheat for indirectly driven capsule implosions on the NIF.

    Science.gov (United States)

    Döppner, T; Dewald, E L; Divol, L; Thomas, C A; Burns, S; Celliers, P M; Izumi, N; Kline, J L; LaCaille, G; McNaney, J M; Prasad, R R; Robey, H F; Glenzer, S H; Landen, O L

    2012-10-01

    We have fielded a hard x-ray (>100 keV) imager with high aspect ratio pinholes to measure the spatially resolved bremsstrahlung emission from energetic electrons slowing in a plastic ablator shell during indirectly driven implosions at the National Ignition Facility. These electrons are generated in laser plasma interactions and are a source of preheat to the deuterium-tritium fuel. First measurements show that hot electron preheat does not limit obtaining the fuel areal densities required for ignition and burn.

  16. Change On The S-Z Effect Induced By The Cooling Flow CF On The Hot Electronic Gas At The Center OF The Clusters Of Galaxies

    Directory of Open Access Journals (Sweden)

    Enkelejd Caca

    2015-06-01

    Full Text Available ABSTRACT Building more accurate profiles for temperature and density of hot electronic gas concentrated in the center of clusters of galaxies is a constant problem in survey of Sunyeav Zeldovich effect SZ. An effect that consists in the inverse Compton effect of the hot electronic gas interacting with Cosmic Microwave Back- ground CMB photons passing through Intra Cluster Medium ICM. So far the Isothermal model is used for temperature profiling in the calculation of the inverse Compton effect but based on the recent improved observations from satellites which showed that the hot electronic gas presents a feature called Cooling Flow CF. Temperatures in this model differs towards the edges of the Clusters of Galaxies leading to a change on the Compton parameter in comparison with Isothermal model. In this paper are processed data provided by X-ray satellite Chandra. The X-ray analysis is based on two models for the electron density and temperature profile. A sample of 12 clusters of galaxies are analyzed and by building the temperature profiles using CF model the differences on the Compton parameter are 10-100 in comparison with Isothermal model. Therefore to increase the accuracy of evaluation of the Compton parameter we should take into account the change of the electronic gas tempera- ture change that affect changes in both CMB spectrum and temperature from SZ effect.

  17. Hydrogen injection device in BWR type reactor

    International Nuclear Information System (INIS)

    Takagi, Jun-ichi; Kubo, Koji.

    1988-01-01

    Purpose: To reduce the increasing ratio of main steam system dose rate due to N-16 activity due to excess hydrogen injection in the hydrogen injection operation of BWR type reactors. Constitution: There are provided a hydrogen injection mechanism for injecting hydrogen into primary coolants of a BWR type reactor, and a chemical injection device for injecting chemicals such as methanol, which makes nitrogen radioisotopes resulted in the reactor water upon hydrogen injection non-volatile, into the pressure vessel separately from hydrogen. Injected hydrogen and the chemicals are not reacted in the feedwater system, but the reaction proceeds due to the presence of radioactive rays after the injection into the pressure vessel. Then, hydrogen causes re-combination in the downcomer portion to reduce the dissolved oxygen concentration. Meanwhile, about 70 % of the chemicals is supplied by means of a jet pump directly to the reactor core, thereby converting the chemical form of N-16 in the reactor core more oxidative (non-volatile). (Kawakami, Y.)

  18. Non-volatile memory based on the ferroelectric photovoltaic effect

    Science.gov (United States)

    Guo, Rui; You, Lu; Zhou, Yang; Shiuh Lim, Zhi; Zou, Xi; Chen, Lang; Ramesh, R.; Wang, Junling

    2013-01-01

    The quest for a solid state universal memory with high-storage density, high read/write speed, random access and non-volatility has triggered intense research into new materials and novel device architectures. Though the non-volatile memory market is dominated by flash memory now, it has very low operation speed with ~10 μs programming and ~10 ms erasing time. Furthermore, it can only withstand ~105 rewriting cycles, which prevents it from becoming the universal memory. Here we demonstrate that the significant photovoltaic effect of a ferroelectric material, such as BiFeO3 with a band gap in the visible range, can be used to sense the polarization direction non-destructively in a ferroelectric memory. A prototype 16-cell memory based on the cross-bar architecture has been prepared and tested, demonstrating the feasibility of this technique. PMID:23756366

  19. Method for refreshing a non-volatile memory

    Science.gov (United States)

    Riekels, James E.; Schlesinger, Samuel

    2008-11-04

    A non-volatile memory and a method of refreshing a memory are described. The method includes allowing an external system to control refreshing operations within the memory. The memory may generate a refresh request signal and transmit the refresh request signal to the external system. When the external system finds an available time to process the refresh request, the external system acknowledges the refresh request and transmits a refresh acknowledge signal to the memory. The memory may also comprise a page register for reading and rewriting a data state back to the memory. The page register may comprise latches in lieu of supplemental non-volatile storage elements, thereby conserving real estate within the memory.

  20. Experimental study of hot electrons propagation and energy deposition in solid or laser-shock compressed targets: applications to fast igniter

    International Nuclear Information System (INIS)

    Pisani, F.

    2000-02-01

    In the fast igniter scheme, a recent approach proposed for the inertial confinement fusion, the idea is to dissociate the fuel ignition phase from its compression. The ignition phase would be then achieved by means of an external energy source: a fast electron beam generated by the interaction with an ultra-intense laser. The main goal of this work is to study the mechanisms of the hot electron energy transfer to the compressed fuel. We intent in particular to study the role of the electric and collisional effects involved in the hot electron propagation in a medium with properties similar to the compressed fuel. We carried out two experiments, one at the Vulcan laser facility (England) and the second one at the new LULI 100 TW laser (France). During the first experiment, we obtained the first results on the hot electron propagation in a dense and hot plasma. The innovating aspect of this work was in particular the use of the laser-shock technique to generate high pressures, allowing the strongly correlated and degenerated plasma to be created. The role of the electric and magnetic effects due to the space charge associated with the fast electron beam has been investigated in the second experiment. Here we studied the propagation in materials with different electrical characteristics: an insulator and a conductor. The analysis of the results showed that only by taking into account simultaneously the two propagation mechanisms (collisions and electric effects) a correct treatment of the energy deposition is possible. We also showed the importance of taking into account the induced modifications due to the electrons beam crossing the target, especially the induced heating. (author)

  1. Active non-volatile memory post-processing

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Sudarsun; Milojicic, Dejan S.; Talwar, Vanish

    2017-04-11

    A computing node includes an active Non-Volatile Random Access Memory (NVRAM) component which includes memory and a sub-processor component. The memory is to store data chunks received from a processor core, the data chunks comprising metadata indicating a type of post-processing to be performed on data within the data chunks. The sub-processor component is to perform post-processing of said data chunks based on said metadata.

  2. Phase change materials in non-volatile storage

    OpenAIRE

    Ielmini, Daniele; Lacaita, Andrea L.

    2011-01-01

    After revolutionizing the technology of optical data storage, phase change materials are being adopted in non-volatile semiconductor memories. Their success in electronic storage is mostly due to the unique properties of the amorphous state where carrier transport phenomena and thermally-induced phase change cooperate to enable high-speed, low-voltage operation and stable data retention possible within the same material. This paper reviews the key physical properties that make this phase so s...

  3. Two-dimensional simulations of laser–plasma interaction and hot electron generation in the context of shock-ignition research

    Czech Academy of Sciences Publication Activity Database

    Klimo, O.; Psikal, J.; Tikhonchuk, V.T.; Weber, Stefan A.

    2014-01-01

    Roč. 56, č. 5 (2014), 055010 ISSN 0741-3335 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279 Institutional support: RVO:68378271 Keywords : laser plasma interaction * stimulated Raman scattering * hot electrons * particle-in-cell simulation Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.186, year: 2014

  4. Use of non-volatile memories for SSC detector readout

    International Nuclear Information System (INIS)

    Fennelly, A.J.; Woosley, J.K.; Johnson, M.B.

    1990-01-01

    Use of non-volatile memory units at the end of each fiber optic bunch/strand would substantially increase information available from experiments by providing a complete event history, in addition to easing real time processing requirements. This may be an alternative to enhancing technology to optical computing techniques. Available and low-risk projected technologies will be surveyed, with costing addressed. Some discussion will be given to covnersion of optical signals, to electronic information, concepts for providing timing pulses to the memory units, and to the magnetoresistive (MRAM) and ferroelectric (FERAM) random access memory technologies that may be utilized in the prototype system

  5. Design considerations for a radiation hardened nonvolatile memory

    International Nuclear Information System (INIS)

    Murray, J.R.

    1993-01-01

    Sub-optimal design practices can reduce the radiation hardness of a circuit even though it is fabricated in a radiation hardened process. This is especially true for a nonvolatile memory, as compared to a standard digital circuit, where high voltages and unusual bias conditions are required. This paper will discuss the design technique's used in the development of a 64K EEPROM (Electrically Erasable Programmable Read Only Memory) to maximize radiation hardness. The circuit radiation test results will be reviewed in order to provide validation of the techniques

  6. Ensemble Monte Carlo particle investigation of hot electron induced source-drain burnout characteristics of GaAs field-effect transistors

    Science.gov (United States)

    Moglestue, C.; Buot, F. A.; Anderson, W. T.

    1995-08-01

    The lattice heating rate has been calculated for GaAs field-effect transistors of different source-drain channel design by means of the ensemble Monte Carlo particle model. Transport of carriers in the substrate and the presence of free surface charges are also included in our simulation. The actual heat generation was obtained by accounting for the energy exchanged with the lattice of the semiconductor during phonon scattering. It was found that the maximum heating rate takes place below the surface near the drain end of the gate. The results correlate well with a previous hydrodynamic energy transport estimate of the electronic energy density, but shifted slightly more towards the drain. These results further emphasize the adverse effects of hot electrons on the Ohmic contacts.

  7. Noise temperature of an NbN hot-electron bolometric mixer at frequencies from 0.7 THz to 5.2 THz

    International Nuclear Information System (INIS)

    Schubert, J.; Semenov, A.; Gol'tsman, G.; Huebers, H-W.; Voronov, B.; Gershenzon, E.; Schwaab, G.

    1999-01-01

    We report on noise temperature measurements of an NbN phonon-cooled hot-electron bolometric mixer in the terahertz frequency range. The devices were 3 nm thick films with in-plane dimensions 1.7x0.2μm 2 and 0.9x0.2μm 2 integrated in a complementary logarithmic-spiral antenna. Measurements were performed at seven frequencies ranging from 0.7 THz to 5.2 THz. The measured DSB noise temperatures are 1500 K (0.7 THz), 2200 K (1.4 THz), 2600 K (1.6 THz), 2900 K (2.5 THz), 4000 K (3.1 THz), 5600 K (4.3 THz) and 8800 K (5.2 THz). (author)

  8. The magic of nanoplasmonics: from superhydrophobic and 3D suspended devices for SERS/TERS-like applications to hot-electrons based nanoscopy

    KAUST Repository

    Alabastri, A.

    2014-05-02

    The ability to confine light in small volumes, associated to low background signals, is an important technological achievement for a number of disciplines such as biology or electronics. In fact, decoupling the source position from the sample area allows an unprecedented sensitivity which can be exploited in different systems. The most direct implications are however related to either Surface Enhanced Raman Scattering (SERS) or Tip Enhanced Raman Scattering (TERS). Furthermore, while the combination with super-hydrophobic patterns can overcome the typical diffusion limit of sensors, focused surface plasmons decaying into hot electrons can be exploited to study the electronic properties of the sample by means of a Schottky junction. Within this paper these techniques will be briefly described and the key role played by both surface and localized plasmons will be highlighted. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  9. The magic of nanoplasmonics: from superhydrophobic and 3D suspended devices for SERS/TERS-like applications to hot-electrons based nanoscopy

    KAUST Repository

    Alabastri, A.; Toma, A.; Giugni, A.; Torre, B.; Malerba, M.; Miele, E.; De Angelis, F.; Liberale, Carlo; Das, Gobind; Di Fabrizio, Enzo M.; Proietti Zaccaria, R.

    2014-01-01

    The ability to confine light in small volumes, associated to low background signals, is an important technological achievement for a number of disciplines such as biology or electronics. In fact, decoupling the source position from the sample area allows an unprecedented sensitivity which can be exploited in different systems. The most direct implications are however related to either Surface Enhanced Raman Scattering (SERS) or Tip Enhanced Raman Scattering (TERS). Furthermore, while the combination with super-hydrophobic patterns can overcome the typical diffusion limit of sensors, focused surface plasmons decaying into hot electrons can be exploited to study the electronic properties of the sample by means of a Schottky junction. Within this paper these techniques will be briefly described and the key role played by both surface and localized plasmons will be highlighted. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  10. Channel equalization techniques for non-volatile memristor memories

    KAUST Repository

    Naous, Rawan

    2016-03-16

    Channel coding and information theoretic approaches have been utilized in conventional non-volatile memories to overcome their inherent design limitations of leakage, coupling and refresh rates. However, the continuous scaling and integration constraints set on the current devices directed the attention towards emerging memory technologies as suitable alternatives. Memristive devices are prominent candidates to replace the conventional electronics due to its non-volatility and small feature size. Nonetheless, memristor-based memories still encounter an accuracy limitation throughout the read operation addressed as the sneak path phenomenon. The readout data is corrupted with added distortion that increases significantly the bit error rate and jeopardizes the reliability of the read operation. A novel technique is applied to alleviate this distorting effect where the communication channel model is proposed for the memory array. Noise cancellation principles are applied with the aid of preset pilots to extract channel information and adjust the readout values accordingly. The proposed technique has the virtue of high speed, energy efficiency, and low complexity design while achieving high reliability and error-free decoding.

  11. Channel equalization techniques for non-volatile memristor memories

    KAUST Repository

    Naous, Rawan; Zidan, Mohammed A.; Salem, Ahmed Sultan; Salama, Khaled N.

    2016-01-01

    Channel coding and information theoretic approaches have been utilized in conventional non-volatile memories to overcome their inherent design limitations of leakage, coupling and refresh rates. However, the continuous scaling and integration constraints set on the current devices directed the attention towards emerging memory technologies as suitable alternatives. Memristive devices are prominent candidates to replace the conventional electronics due to its non-volatility and small feature size. Nonetheless, memristor-based memories still encounter an accuracy limitation throughout the read operation addressed as the sneak path phenomenon. The readout data is corrupted with added distortion that increases significantly the bit error rate and jeopardizes the reliability of the read operation. A novel technique is applied to alleviate this distorting effect where the communication channel model is proposed for the memory array. Noise cancellation principles are applied with the aid of preset pilots to extract channel information and adjust the readout values accordingly. The proposed technique has the virtue of high speed, energy efficiency, and low complexity design while achieving high reliability and error-free decoding.

  12. Femtosecond-laser induced dynamics of CO on Ru(0001): Deep insights from a hot-electron friction model including surface motion

    Science.gov (United States)

    Scholz, Robert; Floß, Gereon; Saalfrank, Peter; Füchsel, Gernot; Lončarić, Ivor; Juaristi, J. I.

    2016-10-01

    A Langevin model accounting for all six molecular degrees of freedom is applied to femtosecond-laser induced, hot-electron driven dynamics of Ru(0001)(2 ×2 ):CO. In our molecular dynamics with electronic friction approach, a recently developed potential energy surface based on gradient-corrected density functional theory accounting for van der Waals interactions is adopted. Electronic friction due to the coupling of molecular degrees of freedom to electron-hole pairs in the metal are included via a local density friction approximation, and surface phonons by a generalized Langevin oscillator model. The action of ultrashort laser pulses enters through a substrate-mediated, hot-electron mechanism via a time-dependent electronic temperature (derived from a two-temperature model), causing random forces acting on the molecule. The model is applied to laser induced lateral diffusion of CO on the surface, "hot adsorbate" formation, and laser induced desorption. Reaction probabilities are strongly enhanced compared to purely thermal processes, both for diffusion and desorption. Reaction yields depend in a characteristic (nonlinear) fashion on the applied laser fluence, as well as branching ratios for various reaction channels. Computed two-pulse correlation traces for desorption and other indicators suggest that aside from electron-hole pairs, phonons play a non-negligible role for laser induced dynamics in this system, acting on a surprisingly short time scale. Our simulations on precomputed potentials allow for good statistics and the treatment of long-time dynamics (300 ps), giving insight into this system which hitherto has not been reached. We find generally good agreement with experimental data where available and make predictions in addition. A recently proposed laser induced population of physisorbed precursor states could not be observed with the present low-coverage model.

  13. Transport and Fatigue Properties of Ferroelectric Polymer P(VDF-TrFE) For Nonvolatile Memory Applications

    KAUST Repository

    Hanna, Amir

    2012-06-01

    Organic ferroelectrics polymers have recently received much interest for use in nonvolatile memory devices. The ferroelectric copolymer poly(vinylidene fluoride- trifluoroethylene) , P(VDF-TrFE), is a promising candidate due to its relatively high remnant polarization, low coercive field, fast switching times, easy processability, and low Curie transition. However, no detailed study of charge injection and current transport properties in P(VDF-TrFE) have been reported in the literature yet. Charge injection and transport are believed to affect various properties of ferroelectric films such as remnant polarization values and polarization fatigue behavior.. Thus, this thesis aims to study charge injection in P(VDF-TrFE) and its transport properties as a function of electrode material. Injection was studied for Al, Ag, Au and Pt electrodes. Higher work function metals such as Pt have shown less leakage current compared to lower work function metals such as Al for more than an order of magnitude. That implied n-type conduction behavior for P(VDF-TrFE), as well as electrons being the dominant injected carrier type. Charge transport was also studied as a function of temperature, and two major transport regimes were identified: 1) Thermionic emission over a Schottky barrier for low fields (E < 25 MV/m). 2) Space-Charge-Limited regime at higher fields (25 < E <120 MV/m). We have also studied the optical imprint phenomenon, the polarization fatigue resulting from a combination of broad band optical illumination and DC bias near the switching field. A setup was designed for the experiment, and validated by reproducing the reported effect in polycrystalline Pb(Zr,Ti)O3 , PZT, film. On the other hand, P(VDF-TrFE) film showed no polarization fatigue as a result of optical imprint test, which could be attributed to the large band gap of the material, and the low intensity of the UV portion of the arc lamp white light used for the experiment. Results suggest using high work

  14. Improvement of tokamak performance by injection of electrons

    International Nuclear Information System (INIS)

    Ono, Masayuki.

    1992-12-01

    Concepts for improving tokamak performance by utilizing injection of hot electrons are discussed. Motivation of this paper is to introduce the research work being performed in this area and to refer the interested readers to the literature for more detail. The electron injection based concepts presented here have been developed in the CDX, CCT, and CDX-U tokamak facilities. The following three promising application areas of electron injection are described here: 1. Non-inductive current drive, 2. Plasma preionization for tokamak start-up assist, and 3. Charging-up of tokamak flux surfaces for improved plasma confinement. The main motivation for the dc-helicity injection current drive is in its efficiency that, in theory, is independent of plasma density. This property makes it attractive for driving currents in high density reactor plasmas

  15. Carbon nanotube network-silicon oxide non-volatile switches.

    Science.gov (United States)

    Liao, Albert D; Araujo, Paulo T; Xu, Runjie; Dresselhaus, Mildred S

    2014-12-08

    The integration of carbon nanotubes with silicon is important for their incorporation into next-generation nano-electronics. Here we demonstrate a non-volatile switch that utilizes carbon nanotube networks to electrically contact a conductive nanocrystal silicon filament in silicon dioxide. We form this device by biasing a nanotube network until it physically breaks in vacuum, creating the conductive silicon filament connected across a small nano-gap. From Raman spectroscopy, we observe coalescence of nanotubes during breakdown, which stabilizes the system to form very small gaps in the network~15 nm. We report that carbon nanotubes themselves are involved in switching the device to a high resistive state. Calculations reveal that this switching event occurs at ~600 °C, the temperature associated with the oxidation of nanotubes. Therefore, we propose that, in switching to a resistive state, the nanotube oxidizes by extracting oxygen from the substrate.

  16. Apple juice composition: sugar, nonvolatile acid, and phenolic profiles.

    Science.gov (United States)

    Lee, H S; Wrolstad, R E

    1988-01-01

    Apples from Michigan, Washington, Argentina, Mexico, and New Zealand were processed into juice; the 8 samples included Golden Delicious, Jonathan, Granny Smith, and McIntosh varieties. Liquid chromatography was used for quantitation of sugars (glucose, fructose, sucrose, and sorbitol), nonvolatile acids (malic, quinic, citric, shikimic, and fumaric), and phenolics (chlorogenic acid and hydroxymethylfurfural [HMF]). Other determinations included pH, 0Brix, and L-malic acid. A number of compositional indices for these authentic juices, e.g., chlorogenic acid content, total malic - L-malic difference, and the HMF:chlorogenic ratio, were at variance with recommended standards. The phenolic profile was shown to be particularly influenced by gelatin fining, with peak areas decreasing by as much as 50%. The L-malic:total malic ratio serves as a better index for presence of synthetic malic acid than does the difference between the 2 determinations. No apparent differences in chemical composition could be attributed to geographic origin.

  17. Bioorganic nanodots for non-volatile memory devices

    International Nuclear Information System (INIS)

    Amdursky, Nadav; Shalev, Gil; Handelman, Amir; Natan, Amir; Rosenwaks, Yossi; Litsyn, Simon; Szwarcman, Daniel; Rosenman, Gil; Roizin, Yakov

    2013-01-01

    In recent years we are witnessing an intensive integration of bio-organic nanomaterials in electronic devices. Here we show that the diphenylalanine bio-molecule can self-assemble into tiny peptide nanodots (PNDs) of ∼2 nm size, and can be embedded into metal-oxide-semiconductor devices as charge storage nanounits in non-volatile memory. For that purpose, we first directly observe the crystallinity of a single PND by electron microscopy. We use these nanocrystalline PNDs units for the formation of a dense monolayer on SiO 2 surface, and study the electron/hole trapping mechanisms and charge retention ability of the monolayer, followed by fabrication of PND-based memory cell device

  18. Bioorganic nanodots for non-volatile memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Amdursky, Nadav; Shalev, Gil; Handelman, Amir; Natan, Amir; Rosenwaks, Yossi [School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Litsyn, Simon; Szwarcman, Daniel; Rosenman, Gil, E-mail: rgil@post.tau.ac.il [School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); StoreDot LTD, 16 Menahem Begin St., Ramat Gan (Israel); Roizin, Yakov [School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); TowerJazz, P.O. Box 619, Migdal HaEmek 23105 (Israel)

    2013-12-01

    In recent years we are witnessing an intensive integration of bio-organic nanomaterials in electronic devices. Here we show that the diphenylalanine bio-molecule can self-assemble into tiny peptide nanodots (PNDs) of ∼2 nm size, and can be embedded into metal-oxide-semiconductor devices as charge storage nanounits in non-volatile memory. For that purpose, we first directly observe the crystallinity of a single PND by electron microscopy. We use these nanocrystalline PNDs units for the formation of a dense monolayer on SiO{sub 2} surface, and study the electron/hole trapping mechanisms and charge retention ability of the monolayer, followed by fabrication of PND-based memory cell device.

  19. Organic nonvolatile memory devices with charge trapping multilayer graphene film

    International Nuclear Information System (INIS)

    Ji, Yongsung; Choe, Minhyeok; Cho, Byungjin; Song, Sunghoon; Yoon, Jongwon; Ko, Heung Cho; Lee, Takhee

    2012-01-01

    We fabricated an array-type organic nonvolatile memory device with multilayer graphene (MLG) film embedded in polyimide (PI) layers. The memory devices showed a high ON/OFF ratio (over 10 6 ) and a long retention time (over 10 4 s). The switching of the Al/PI/MLG/PI/Al memory devices was due to the presence of the MLG film inserted into the PI layers. The double-log current–voltage characteristics could be explained by the space-charge-limited current conduction based on a charge-trap model. A conductive atomic force microscopy found that the conduction paths in the low-resistance ON state were distributed in a highly localized area, which was associated with a carbon-rich filamentary switching mechanism. (paper)

  20. Non-volatile polarization switch of magnetic domain wall velocity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z.; Stolichnov, I.; Setter, N. [Ceramics Laboratory, EPFL-Swiss Federal Institute of Technology, Lausanne 1015 (Switzerland); Bernand-Mantel, A.; Schott, Marine; Pizzini, S.; Ranno, L. [University of Grenoble Alpes, Institut Néel, F-38042 Grenoble (France); CNRS, Institut Néel, F-38042 Grenoble (France); Auffret, S.; Gaudin, G. [SPINTEC, UMR-8191, CEA/CNRS/UJF/GINP, INAC, F-38054 Grenoble (France)

    2015-12-21

    Controlled propagation speed of individual magnetic domains in metal channels at the room temperature is obtained via the non-volatile field effect associated with the switchable polarization of P(VDF-TrFE) (polyvinylidene fluoride-trifluoroethylene) ferroelectric polymer. Polarization domains directly written using conducting atomic force microscope probe locally accelerate/decelerate the magnetic domains in the 0.6 nm thick Co film. The change of the magnetic domain wall velocity is consistent with the magnetic anisotropy energy modulation through the polarization upward/downward orientation. Excellent retention is observed. The demonstrated local non-destructive and reversible change of magnetic properties via rewritable patterning of ferroelectric domains could be attractive for exploring the ultimate limit of miniaturization in devices based on ferromagnetic/ferroelectric bilayers.

  1. Multistate nonvolatile straintronics controlled by a lateral electric field

    International Nuclear Information System (INIS)

    Iurchuk, V; Doudin, B; Kundys, B

    2014-01-01

    We present a multifunctional and multistate permanent memory device based on lateral electric field control of a strained surface. Sub-coercive electrical writing of a remnant strain of a PZT substrate imprints stable and rewritable resistance changes on a CoFe overlayer. A proof-of-principle device, with the simplest resistance strain gage design, is shown as a memory cell exhibiting 17-memory states of high reproducibility and reliability for nonvolatile operations. Magnetoresistance of the film also depends on the cell state, and indicates a rewritable change of magnetic properties persisting in the remnant strain of the substrate. This makes it possible to combine strain, magnetic and resistive functionalities in a single memory element, and suggests that sub-coercive stress studies are of interest for straintronics applications. (fast track communication)

  2. Multistate nonvolatile straintronics controlled by a lateral electric field.

    Science.gov (United States)

    Iurchuk, V; Doudin, B; Kundys, B

    2014-07-23

    We present a multifunctional and multistate permanent memory device based on lateral electric field control of a strained surface. Sub-coercive electrical writing of a remnant strain of a PZT substrate imprints stable and rewritable resistance changes on a CoFe overlayer. A proof-of-principle device, with the simplest resistance strain gage design, is shown as a memory cell exhibiting 17-memory states of high reproducibility and reliability for nonvolatile operations. Magnetoresistance of the film also depends on the cell state, and indicates a rewritable change of magnetic properties persisting in the remnant strain of the substrate. This makes it possible to combine strain, magnetic and resistive functionalities in a single memory element, and suggests that sub-coercive stress studies are of interest for straintronics applications.

  3. Nonvolatile memory effect of tungsten nanocrystals under oxygen plasma treatments

    International Nuclear Information System (INIS)

    Chen, Shih-Cheng; Chang, Ting-Chang; Chen, Wei-Ren; Lo, Yuan-Chun; Wu, Kai-Ting; Sze, S.M.; Chen, Jason; Liao, I.H.; Yeh, Fon-Shan

    2010-01-01

    In this work, an oxygen plasma treatment was used to improve the memory effect of nonvolatile W nanocrystal memory, including memory window, retention and endurance. To investigate the role of the oxygen plasma treatment in charge storage characteristics, the X-ray photon-emission spectra (XPS) were performed to analyze the variation of chemical composition for W nanocrystal embedded oxide both with and without the oxygen plasma treatment. In addition, the transmission electron microscopy (TEM) analyses were also used to identify the microstructure in the thin film and the size and density of W nanocrystals. The device with the oxygen plasma treatment shows a significant improvement of charge storage effect, because the oxygen plasma treatment enhanced the quality of silicon oxide surrounding the W nanocrystals. Therefore, the data retention and endurance characteristics were also improved by the passivation.

  4. Testosterone Injection

    Science.gov (United States)

    ... typical male characteristics. Testosterone injection works by supplying synthetic testosterone to replace the testosterone that is normally ... as a pellet to be injected under the skin.Testosterone injection may control your symptoms but will ...

  5. Theoretical predictions for the polarization of the J = 0 - 1 neonlike germanium X-ray laser line in the presence of a directed beam of hot electrons

    International Nuclear Information System (INIS)

    Inal, M.K.; Dubau, J.; Cornille, M.

    1998-01-01

    The polarization of the neonlike germanium J = 0 - 1 laser line, which would arise from the existence of a directed beam of hot electrons in the amplifying plasma, is theoretically investigated. The relative populations of the magnetic sublevels in the lower J = 1 laser level have been determined by allowing for the processes of direct excitation from the 2p 6 ground level and collisional de-excitation from the upper J = 0 laser level. Elastic collisions leading to transitions between the M J = 0 and M J =1 sublevels within the lower level of the lasing line have also been taken into account. The required elastic and inelastic collision strengths for transitions between magnetic sublevels have been computed in a semi-relativistic distorted-wave approximation, for incident electron energies up to 15 keV. Our calculations predict a rather low degree of polarization for the J = 0 - 1 line, although the elastic collisions are found to play a negligibly small role in the redistribution of magnetic sublevel populations. (author)

  6. High-performance non-volatile organic ferroelectric memory on banknotes

    KAUST Repository

    Khan, Yasser; Bhansali, Unnat Sampatraj; Alshareef, Husam N.

    2012-01-01

    High-performance non-volatile polymer ferroelectric memory are fabricated on banknotes using poly(vinylidene fluoride trifluoroethylene). The devices show excellent performance with high remnant polarization, low operating voltages, low leakage

  7. Crested Tunnel Barriers for Fast, Scalable, Nonvolatile Semiconductor Memories (Theme 3)

    National Research Council Canada - National Science Library

    Likharev, Konstantin K; Ma, Tso-Ping

    2006-01-01

    .... If demonstrated in silicon-compatible materials with sufficient endurance under electric stress, this effect may enable high-density, high-speed nonvolatile memories that may potentially replace DRAM...

  8. Role of Non-Volatile Memories in Automotive and IoT Markets

    Science.gov (United States)

    2017-03-01

    Standard Manufacturing Supply Long Term Short to Medium Term Density Up to 16MB Up to 2MB IO Configuration Up to x128 Up to x32 Design for Test...Role of Non-Volatile Memories in Automotive and IoT Markets Vipin Tiwari Director, Business Development and Product Marketing SST – A Wholly Own...microcontrollers (MCU) and certainly one of the most challenging elements to master. This paper addresses the role of non-volatile memories for

  9. Mass transfer of nonvolatile organic compounds from porous media

    Science.gov (United States)

    Khachikian, Crist Simon

    This thesis presents data pertaining to the mass transfer of nonvolatile organic compounds from porous media. Physical properties of porous solids, including surface and pore areas, are studied. Information from these studies, along with dissolution data, are used to develop correlations relating the Sherwood Number to the Peclet Number. The contaminant used in this study is naphthalene; the solids used are Moffett Sand (MS), Borden Sand (BS), Lampblack (LB), and Silica Gel (SG). Surface area results indicate that contamination at 0.1% reduces the area of MS and SG by 48 and 37%, respectively, while contamination at 1.0% reduces the area of MS, BS, and SG by 59, 56, and 40%, respectively. Most of the reduction in area originates in the reduction of pore areas and volumes, where the contaminant precipitates. After long-term storage, surface areas did not recover to their original values due to an "irreversible" fraction of naphthalene. Treatment with heat or solvent or both was necessary to completely remove the contamination. For lampblack, treatment at 100°C decreased areas while treatment at 250°C increased them. Treatment at 250°°C probably opened pores while that at 100°C may have blocked more pores by redistributing the tar-like contaminant characteristic of lampblack. Contaminated MS and SG solids are packed in columns through which water is pumped. The effluent began at a relatively high concentration (˜70% of solubility) for both samples. However, SG column concentrations dropped quickly, never achieving steady state while the MS samples declined more gradually towards steady state. The high pore areas of the SG samples are believed to cause this behavior. The steady state portion of the MS dissolution history is used to develop mass transfer correlations. The correlation in this study differs from previous work in two major ways: (1) the exponent on the Pe is three times larger and (2) the limiting Sh is 106 times smaller. These results suggest that

  10. Tunable Injection Barrier in Organic Resistive Switches Based on Phase-Separated Ferroelectric-Semiconductor Blends

    NARCIS (Netherlands)

    Asadi, Kamal; de Boer, Tom G.; Blom, Paul W. M.; de Leeuw, Dago M.

    2009-01-01

    Organic non-volatile resistive bistable diodes based on phase-separated blends of ferroelectric and semiconducting polymers are fabricated. The polarization field of the ferroelectric modulates the injection barrier at the semiconductor-electrode contact and, hence, the resistance of the comprising

  11. Tunable injection barrier in organic resistive switches based on phase-separated ferroelectric-semiconductor blends

    NARCIS (Netherlands)

    Asadi, K.; Boer, T.G. de; Blom, P.W.M.; Leeuw, D.M. de

    2009-01-01

    Organic non-volatile resistive bistable diodes based on phase-separated blends of ferroelectric and semiconducting polymers are fabricated. The polarization field of the ferroelectric modulates the injection barrier at the semiconductor-electrode contact and, hence, the resistance of the comprising

  12. Electrostatic Switching in Vertically Oriented Nanotubes for Nonvolatile Memory Applications

    Science.gov (United States)

    Kaul, Anupama B.; Khan, Paul; Jennings, Andrew T.; Greer, Julia R.; Megerian, Krikor G.; Allmen, Paul von

    2009-01-01

    We have demonstrated electrostatic switching in vertically oriented nanotubes or nanofibers, where a nanoprobe was used as the actuating electrode inside an SEM. When the nanoprobe was manipulated to be in close proximity to a single tube, switching voltages between 10 V - 40 V were observed, depending on the geometrical parameters. The turn-on transitions appeared to be much sharper than the turn-off transitions which were limited by the tube-to-probe contact resistances. In many cases, stiction forces at these dimensions were dominant, since the tube appeared stuck to the probe even after the voltage returned to 0 V, suggesting that such structures are promising for nonvolatile memory applications. The stiction effects, to some extent, can be adjusted by engineering the switch geometry appropriately. Nanoscale mechanical measurements were also conducted on the tubes using a custom-built anoindentor inside an SEM, from which preliminary material parameters, such as the elastic modulus, were extracted. The mechanical measurements also revealed that the tubes appear to be well adhered to the substrate. The material parameters gathered from the mechanical measurements were then used in developing an electrostatic model of the switch using a commercially available finite-element simulator. The calculated pull-in voltages appeared to be in agreement to the experimentally obtained switching voltages to first order.

  13. Highly Stretchable Non-volatile Nylon Thread Memory

    Science.gov (United States)

    Kang, Ting-Kuo

    2016-04-01

    Integration of electronic elements into textiles, to afford e-textiles, can provide an ideal platform for the development of lightweight, thin, flexible, and stretchable e-textiles. This approach will enable us to meet the demands of the rapidly growing market of wearable-electronics on arbitrary non-conventional substrates. However the actual integration of the e-textiles that undergo mechanical deformations during both assembly and daily wear or satisfy the requirements of the low-end applications, remains a challenge. Resistive memory elements can also be fabricated onto a nylon thread (NT) for e-textile applications. In this study, a simple dip-and-dry process using graphene-PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) ink is proposed for the fabrication of a highly stretchable non-volatile NT memory. The NT memory appears to have typical write-once-read-many-times characteristics. The results show that an ON/OFF ratio of approximately 103 is maintained for a retention time of 106 s. Furthermore, a highly stretchable strain and a long-term digital-storage capability of the ON-OFF-ON states are demonstrated in the NT memory. The actual integration of the knitted NT memories into textiles will enable new design possibilities for low-cost and large-area e-textile memory applications.

  14. Graphene-quantum-dot nonvolatile charge-trap flash memories

    International Nuclear Information System (INIS)

    Sin Joo, Soong; Kim, Jungkil; Seok Kang, Soo; Kim, Sung; Choi, Suk-Ho; Won Hwang, Sung

    2014-01-01

    Nonvolatile flash-memory capacitors containing graphene quantum dots (GQDs) of 6, 12, and 27 nm average sizes (d) between SiO 2 layers for use as charge traps have been prepared by sequential processes: ion-beam sputtering deposition (IBSD) of 10 nm SiO 2 on a p-type wafer, spin-coating of GQDs on the SiO 2 layer, and IBSD of 20 nm SiO 2 on the GQD layer. The presence of almost a single array of GQDs at a distance of ∼13 nm from the SiO 2 /Si wafer interface is confirmed by transmission electron microscopy and photoluminescence. The memory window estimated by capacitance–voltage curves is proportional to d for sweep voltages wider than  ± 3 V, and for d = 27 nm the GQD memories show a maximum memory window of 8 V at a sweep voltage of  ± 10 V. The program and erase speeds are largest at d = 12 and 27 nm, respectively, and the endurance and data-retention properties are the best at d = 27 nm. These memory behaviors can be attributed to combined effects of edge state and quantum confinement. (papers)

  15. A graphene-based non-volatile memory

    Science.gov (United States)

    Loisel, Loïc.; Maurice, Ange; Lebental, Bérengère; Vezzoli, Stefano; Cojocaru, Costel-Sorin; Tay, Beng Kang

    2015-09-01

    We report on the development and characterization of a simple two-terminal non-volatile graphene switch. After an initial electroforming step during which Joule heating leads to the formation of a nano-gap impeding the current flow, the devices can be switched reversibly between two well-separated resistance states. To do so, either voltage sweeps or pulses can be used, with the condition that VSET achieve reversible switching on more than 100 cycles with resistance ratio values of 104. This approach of graphene memory is competitive as compared to other graphene approaches such as redox of graphene oxide, or electro-mechanical switches with suspended graphene. We suggest a switching model based on a planar electro-mechanical switch, whereby electrostatic, elastic and friction forces are competing to switch devices ON and OFF, and the stability in the ON state is achieved by the formation of covalent bonds between the two stretched sides of the graphene, hence bridging the nano-gap. Developing a planar electro-mechanical switch enables to obtain the advantages of electro-mechanical switches while avoiding most of their drawbacks.

  16. Quantitative reconstruction of the nonvolatile sensometabolome of a red wine.

    Science.gov (United States)

    Hufnagel, Jan Carlos; Hofmann, Thomas

    2008-10-08

    The first comprehensive quantitative determination of 82 putative taste-active metabolites and mineral salts, the ranking of these compounds in their sensory impact based on dose-over-threshold (DoT) factors, followed by the confirmation of their sensory relevance by taste reconstruction and omission experiments enabled the decoding of the nonvolatile sensometabolome of a red wine. For the first time, the bitterness of the red wine could be demonstrated to be induced by subthreshold concentrations of phenolic acid ethyl esters and flavan-3-ols. Whereas the velvety astringent onset was imparted by three flavon-3-ol glucosides and dihydroflavon-3-ol rhamnosides, the puckering astringent offset was caused by a polymeric fraction exhibiting molecular masses above >5 kDa and was found to be amplified by the organic acids. The perceived sourness was imparted by l-tartaric acid, d-galacturonic acid, acetic acid, succinic acid, l-malic acid, and l-lactic acid and was slightly suppressed by the chlorides of potassium, magnesium, and ammonium, respectively. In addition, d-fructose and glycerol as well as subthreshold concentrations of glucose, 1,2-propandiol, and myo-inositol were found to be responsible for the sweetness, whereas the mouthfulness and body of the red wine were induced only by glycerol, 1,2-propandiol, and myo-inositol.

  17. Untargeted metabolomic analysis using liquid chromatography quadrupole time-of-flight mass spectrometry for non-volatile profiling of wines

    International Nuclear Information System (INIS)

    Arbulu, M.; Sampedro, M.C.; Gómez-Caballero, A.; Goicolea, M.A.; Barrio, R.J.

    2015-01-01

    Highlights: • An untargeted metabolomic method for the non-volatile profile of the Graciano wine was developed. • 411 different metabolites in Graciano Vitis vinifera red wine were identified. • 15 compounds could serve to differentiate Graciano and Tempranillo wines. • An enological database (WinMet) with 2080 compounds was constructed. - Abstract: The current study presents a method for comprehensive untargeted metabolomic fingerprinting of the non-volatile profile of the Graciano Vitis vinifera wine variety, using liquid chromatography/electrospray ionization time of flight mass spectrometry (LC–ESI-QTOF). Pre-treatment of samples, chromatographic columns, mobile phases, elution gradients and ionization sources, were evaluated for the extraction of the maximum number of metabolites in red wine. Putative compounds were extracted from the raw data using the extraction algorithm, molecular feature extractor (MFE). For the metabolite identification the WinMet database was designed based on electronic databases and literature research and includes only the putative metabolites reported to be present in oenological matrices. The results from WinMet were compared with those in the METLIN database to evaluate how much the databases overlap for performing identifications. The reproducibility of the analysis was assessed using manual processing following replicate injections of Vitis vinifera cv. Graciano wine spiked with external standards. In the present work, 411 different metabolites in Graciano Vitis vinifera red wine were identified, including primary wine metabolites such as sugars (4%), amino acids (23%), biogenic amines (4%), fatty acids (2%), and organic acids (32%) and secondary metabolites such as phenols (27%) and esters (8%). Significant differences between varieties Tempranillo and Graciano were related to the presence of fifteen specific compounds

  18. Untargeted metabolomic analysis using liquid chromatography quadrupole time-of-flight mass spectrometry for non-volatile profiling of wines

    Energy Technology Data Exchange (ETDEWEB)

    Arbulu, M. [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Sampedro, M.C. [Central Service of Analysis, SGIker, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Gómez-Caballero, A.; Goicolea, M.A. [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Barrio, R.J., E-mail: r.barrio@ehu.es [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain)

    2015-02-09

    Highlights: • An untargeted metabolomic method for the non-volatile profile of the Graciano wine was developed. • 411 different metabolites in Graciano Vitis vinifera red wine were identified. • 15 compounds could serve to differentiate Graciano and Tempranillo wines. • An enological database (WinMet) with 2080 compounds was constructed. - Abstract: The current study presents a method for comprehensive untargeted metabolomic fingerprinting of the non-volatile profile of the Graciano Vitis vinifera wine variety, using liquid chromatography/electrospray ionization time of flight mass spectrometry (LC–ESI-QTOF). Pre-treatment of samples, chromatographic columns, mobile phases, elution gradients and ionization sources, were evaluated for the extraction of the maximum number of metabolites in red wine. Putative compounds were extracted from the raw data using the extraction algorithm, molecular feature extractor (MFE). For the metabolite identification the WinMet database was designed based on electronic databases and literature research and includes only the putative metabolites reported to be present in oenological matrices. The results from WinMet were compared with those in the METLIN database to evaluate how much the databases overlap for performing identifications. The reproducibility of the analysis was assessed using manual processing following replicate injections of Vitis vinifera cv. Graciano wine spiked with external standards. In the present work, 411 different metabolites in Graciano Vitis vinifera red wine were identified, including primary wine metabolites such as sugars (4%), amino acids (23%), biogenic amines (4%), fatty acids (2%), and organic acids (32%) and secondary metabolites such as phenols (27%) and esters (8%). Significant differences between varieties Tempranillo and Graciano were related to the presence of fifteen specific compounds.

  19. Rhodium Catalysts in the Oxidation of CO by O2 and NO: Shape, Composition, and Hot Electron Generation

    Energy Technology Data Exchange (ETDEWEB)

    Renzas, James R. [Univ. of California, Berkeley, CA (United States)

    2010-03-08

    It is well known that the activity, selectivity, and deactivation behavior of heterogeneous catalysts are strongly affected by a wide variety of parameters, including but not limited to nanoparticle size, shape, composition, support, pretreatment conditions, oxidation state, and electronic state. Enormous effort has been expended in an attempt to understand the role of these factors on catalytic behavior, but much still remains to be discovered. In this work, we have focused on deepening the present understanding of the role of nanoparticle shape, nanoparticle composition, and hot electrons on heterogeneous catalysis in the oxidation of carbon monoxide by molecular oxygen and nitric oxide. These reactions were chosen because they are important for environmental applications, such as in the catalytic converter, and because there is a wide range of experimental and theoretical insight from previous single crystal work as well as experimental data on nanoparticles obtained using new state-of-the-art techniques that aid greatly in the interpretation of results on complex nanoparticle systems. In particular, the studies presented in this work involve three types of samples: ~ 6.5 nm Rh nanoparticles of different shapes, ~ 15 nm Rh1-xPdx core-shell bimetallic polyhedra nanoparticles, and Rh ultra-thin film (~ 5 nm) catalytic nanodiodes. The colloidal nanoparticle samples were synthesized using a co-reduction of metal salts in alcohol and supported on silicon wafers using the Langmuir-Blodgett technique. This synthetic strategy enables tremendous control of nanoparticle size, shape, and composition. Nanoparticle shape was controlled through the use of different organic polymer capping layers. Bimetallic core-shell nanoparticles were synthesized by careful choice of metal salt precursors. Rh/TiOx and Rh/GaN catalytic nanodiodes were fabricated using a variety of thin film device fabrication techniques, including reactive DC magnetron

  20. Nanopatterned ferroelectrics for ultrahigh density rad-hard nonvolatile memories.

    Energy Technology Data Exchange (ETDEWEB)

    Brennecka, Geoffrey L.; Stevens, Jeffrey; Scrymgeour, David; Gin, Aaron V.; Tuttle, Bruce Andrew

    2010-09-01

    Radiation hard nonvolatile random access memory (NVRAM) is a crucial component for DOE and DOD surveillance and defense applications. NVRAMs based upon ferroelectric materials (also known as FERAMs) are proven to work in radiation-rich environments and inherently require less power than many other NVRAM technologies. However, fabrication and integration challenges have led to state-of-the-art FERAMs still being fabricated using a 130nm process while competing phase-change memory (PRAM) has been demonstrated with a 20nm process. Use of block copolymer lithography is a promising approach to patterning at the sub-32nm scale, but is currently limited to self-assembly directly on Si or SiO{sub 2} layers. Successful integration of ferroelectrics with discrete and addressable features of {approx}15-20nm would represent a 100-fold improvement in areal memory density and would enable more highly integrated electronic devices required for systems advances. Towards this end, we have developed a technique that allows us to carry out block copolymer self-assembly directly on a huge variety of different materials and have investigated the fabrication, integration, and characterization of electroceramic materials - primarily focused on solution-derived ferroelectrics - with discrete features of {approx}20nm and below. Significant challenges remain before such techniques will be capable of fabricating fully integrated NVRAM devices, but the tools developed for this effort are already finding broader use. This report introduces the nanopatterned NVRAM device concept as a mechanism for motivating the subsequent studies, but the bulk of the document will focus on the platform and technology development.

  1. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  2. Granisetron Injection

    Science.gov (United States)

    Granisetron immediate-release injection is used to prevent nausea and vomiting caused by cancer chemotherapy and to ... nausea and vomiting that may occur after surgery. Granisetron extended-release (long-acting) injection is used with ...

  3. Edaravone Injection

    Science.gov (United States)

    Edaravone injection is used to treat amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease; a condition in which ... die, causing the muscles to shrink and weaken). Edaravone injection is in a class of medications called ...

  4. Meropenem Injection

    Science.gov (United States)

    ... injection is in a class of medications called antibiotics. It works by killing bacteria that cause infection.Antibiotics such as meropenem injection will not work for colds, flu, or other viral infections. Taking ...

  5. Chloramphenicol Injection

    Science.gov (United States)

    ... injection is in a class of medications called antibiotics. It works by stopping the growth of bacteria..Antibiotics such as chloramphenicol injection will not work for colds, flu, or other viral infections. Taking ...

  6. Colistimethate Injection

    Science.gov (United States)

    ... injection is in a class of medications called antibiotics. It works by killing bacteria.Antibiotics such as colistimethate injection will not work for colds, flu, or other viral infections. Using ...

  7. Defibrotide Injection

    Science.gov (United States)

    Defibrotide injection is used to treat adults and children with hepatic veno-occlusive disease (VOD; blocked blood ... the body and then returned to the body). Defibrotide injection is in a class of medications called ...

  8. Nalbuphine Injection

    Science.gov (United States)

    ... injection is in a class of medications called opioid agonist-antagonists. It works by changing the way ... suddenly stop using nalbuphine injection, you may experience withdrawal symptoms including restlessness; teary eyes; runny nose; yawning; ...

  9. Volatile and Nonvolatile Characteristics of Asymmetric Dual-Gate Thyristor RAM with Vertical Structure.

    Science.gov (United States)

    Kim, Hyun-Min; Kwon, Dae Woong; Kim, Sihyun; Lee, Kitae; Lee, Junil; Park, Euyhwan; Lee, Ryoongbin; Kim, Hyungjin; Kim, Sangwan; Park, Byung-Gook

    2018-09-01

    In this paper, the volatile and nonvolatile characteristics of asymmetric dual-gate thyristor random access memory (TRAM) are investigated using the technology of a computer-aided design (TCAD) simulation. Owing to the use of two independent gates having different gate dielectric layers, volatile and nonvolatile memory functions can be realized in a single device. The first gate with a silicon oxide layer controls the one-transistor dynamic random access memory (1T-DRAM) characteristics of the device. From the simulation results, a rapid write speed (107) can be achieved. The second gate, whose dielectric material is composed of oxide/nitride/oxide (O/N/O) layers, is used to implement the nonvolatile property by trapping charges in the nitride layer. In addition, this offers an advantage when processing the 3D-stack memory application, as the device has a vertical channel structure with polycrystalline silicon.

  10. Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China

    Science.gov (United States)

    Cheung, Heidi H. Y.; Tan, Haobo; Xu, Hanbing; Li, Fei; Wu, Cheng; Yu, Jian Z.; Chan, Chak K.

    2016-07-01

    Simultaneous measurements of aerosol volatility and carbonaceous matters were conducted at a suburban site in Guangzhou, China, in February and March 2014 using a volatility tandem differential mobility analyzer (VTDMA) and an organic carbon/elemental carbon (OC / EC) analyzer. Low volatility (LV) particles, with a volatility shrink factor (VSF) at 300 °C exceeding 0.9, contributed 5 % of number concentrations of the 40 nm particles and 11-15 % of the 80-300 nm particles. They were composed of non-volatile material externally mixed with volatile material, and therefore did not evaporate significantly at 300 °C. Non-volatile material mixed internally with the volatile material was referred to as medium volatility (MV, 0.4 transported at low altitudes (below 1500 m) for over 40 h before arrival. Further comparison with the diurnal variations in the mass fractions of EC and the non-volatile OC in PM2.5 suggests that the non-volatile residuals may be related to both EC and non-volatile OC in the afternoon, during which the concentration of aged organics increased. A closure analysis of the total mass of LV and MV residuals and the mass of EC or the sum of EC and non-volatile OC was conducted. It suggests that non-volatile OC, in addition to EC, was one of the components of the non-volatile residuals measured by the VTDMA in this study.

  11. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123 (China)

    2014-10-20

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  12. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    International Nuclear Information System (INIS)

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong

    2014-01-01

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  13. Enhanced non-volatile and updatable holography using a polymer composite system.

    Science.gov (United States)

    Wu, Pengfei; Sun, Sam Q; Baig, Sarfaraz; Wang, Michael R

    2012-03-12

    Updatable holography is considered as the ultimate technique for true 3D information recording and display. However, there is no practical solution to preserve the required features of both non-volatility and reversibility which conflict with each other when the reading has the same wavelength as the recording. We demonstrate a non-volatile and updatable holographic approach by exploiting new features of molecular transformations in a polymer recording system. In addition, by using a new composite recording film containing photo-reconfigurable liquid-crystal (LC) polymer, the holographic recording is enhanced due to the collective reorientation of LC molecules around the reconfigured polymer chains.

  14. Nonvolatile flip-flop based on pseudo-spin-transistor architecture and its nonvolatile power-gating applications for low-power CMOS logic

    Science.gov (United States)

    Yamamoto, Shuu'ichirou; Shuto, Yusuke; Sugahara, Satoshi

    2013-07-01

    We computationally analyzed performance and power-gating (PG) ability of a new nonvolatile delay flip-flop (NV-DFF) based on pseudo-spin-MOSFET (PS-MOSFET) architecture using spin-transfer-torque magnetic tunnel junctions (STT-MTJs). The high-performance energy-efficient PG operations of the NV-DFF can be achieved owing to its cell structure employing PS-MOSFETs that can electrically separate the STT-MTJs from the ordinary DFF part of the NV-DFF. This separation also makes it possible that the break-even time (BET) of the NV-DFF is designed by the size of the PS-MOSFETs without performance degradation of the normal DFF operations. The effect of the area occupation ratio of the NV-DFFs to a CMOS logic system on the BET was also analyzed. Although the optimized BET was varied depending on the area occupation ratio, energy-efficient fine-grained PG with a BET of several sub-microseconds was revealed to be achieved. We also proposed microprocessors and system-on-chip (SoC) devices using nonvolatile hierarchical-memory systems wherein NV-DFF and nonvolatile static random access memory (NV-SRAM) circuits are used as fundamental building blocks. Contribution to the Topical Issue “International Semiconductor Conference Dresden-Grenoble - ISCDG 2012”, Edited by Gérard Ghibaudo, Francis Balestra and Simon Deleonibus.

  15. Optically controlled seeding of Raman forward scattering and injection of electrons in a self-modulated laser-wakefield accelerator

    International Nuclear Information System (INIS)

    Chen, W.-T.; Chien, T.-Y.; Lee, C.-H.; Lin, J.-Y.; Wang, J.; Chen, S.-Y.

    2004-01-01

    Optical seeding of plasma waves and the injection of electrons are key issues in self-modulated laser-wakefield accelerators. By implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. The dependence of the Raman intensity on prepulse timing indicates that the seeding of Raman forward scattering is dominated by the ionization-induced wakefield, and the dependence of the divergence and number of accelerated electrons further reveals that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the main pulse

  16. Subcutaneous Injections

    DEFF Research Database (Denmark)

    Thomsen, Maria

    This thesis is about visualization and characterization of the tissue-device interaction during subcutaneous injection. The tissue pressure build-up during subcutaneous injections was measured in humans. The insulin pen FlexTouchr (Novo Nordisk A/S) was used for the measurements and the pressure ...

  17. Hydromorphone Injection

    Science.gov (United States)

    ... anyone else to use your medication. Store hydromorphone injection in a safe place so that no one else can use it accidentally or on purpose. Keep track of how much medication is left so ... with hydromorphone injection may increase the risk that you will develop ...

  18. Ketorolac Injection

    Science.gov (United States)

    ... an older adult, you should know that ketorolac injection is not as safe as other medications that can be used to treat your condition. Your doctor may choose to prescribe a different medication ... to ketorolac injection.Your doctor or pharmacist will give you the ...

  19. Paclitaxel Injection

    Science.gov (United States)

    (pak'' li tax' el)Paclitaxel injection must be given in a hospital or medical facility under the supervision of a doctor who is experienced in giving chemotherapy medications for cancer.Paclitaxel injection may cause a large decrease in the number of white blood cells (a type of blood cell ...

  20. WORKSHOP REPORT - CONSIDERATIONS FOR DEVELOPING LEACHING TEST METHODS FOR SEMI- AND NON-VOLATILE ORGANIC COMPOUNDS

    Science.gov (United States)

    The report provides a summary of the information exchange at a workshop on the potential for release of semi- or non-volatile organic constituents at contaminated sites where sub-surface treatment has been used to control migration, and from waste that is disposed or re-used. The...

  1. Low-power non-volatile spintronic memory: STT-RAM and beyond

    International Nuclear Information System (INIS)

    Wang, K L; Alzate, J G; Khalili Amiri, P

    2013-01-01

    The quest for novel low-dissipation devices is one of the most critical for the future of semiconductor technology and nano-systems. The development of a low-power, universal memory will enable a new paradigm of non-volatile computation. Here we consider STT-RAM as one of the emerging candidates for low-power non-volatile memory. We show different configurations for STT memory and demonstrate strategies to optimize key performance parameters such as switching current and energy. The energy and scaling limits of STT-RAM are discussed, leading us to argue that alternative writing mechanisms may be required to achieve ultralow power dissipation, a necessary condition for direct integration with CMOS at the gate level for non-volatile logic purposes. As an example, we discuss the use of the giant spin Hall effect as a possible alternative to induce magnetization reversal in magnetic tunnel junctions using pure spin currents. Further, we concentrate on magnetoelectric effects, where electric fields are used instead of spin-polarized currents to manipulate the nanomagnets, as another candidate solution to address the challenges of energy efficiency and density. The possibility of an electric-field-controlled magnetoelectric RAM as a promising candidate for ultralow-power non-volatile memory is discussed in the light of experimental data demonstrating voltage-induced switching of the magnetization and reorientation of the magnetic easy axis by electric fields in nanomagnets. (paper)

  2. High-performance non-volatile organic ferroelectric memory on banknotes

    KAUST Repository

    Khan, Yasser

    2012-03-21

    High-performance non-volatile polymer ferroelectric memory are fabricated on banknotes using poly(vinylidene fluoride trifluoroethylene). The devices show excellent performance with high remnant polarization, low operating voltages, low leakage, high mobility, and long retention times. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Feasibility of nonvolatile buffers in capillary electrophoresis-electrospray ionization-mass spectrometry of proteins

    NARCIS (Netherlands)

    Eriksson, Jonas H.C.; Mol, Roelof; Somsen, Govert W.; Hinrichs, Wouter L.J.; Frijlink, Henderik W.; de Jong, Gerhardus J.

    2004-01-01

    The combination of capillary electrophoresis (CE) and electrospray ionization-mass spectrometry (ESI-MS) via a triaxial interface was studied as a potential means for the characterization of intact proteins. To evaluate the possibility to use a nonvolatile electrolyte for CE, the effect of sodium

  4. Low-temperature process steps for realization of non-volatile memory devices

    NARCIS (Netherlands)

    Brunets, I.; Boogaard, A.; Aarnink, Antonius A.I.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.; Holleman, J.; Schmitz, Jurriaan

    2007-01-01

    In this work, the low-temperature process steps required for the realization of nano-crystal non-volatile memory cells are discussed. An amorphous silicon film, crystallized using a diode pumped solid state green laser irradiating at 532 nm, is proposed as an active layer. The deposition of the

  5. The retention characteristics of nonvolatile SNOS memory transistors in a radiation environment: Experiment and model

    International Nuclear Information System (INIS)

    McWhorter, P.J.; Miller, S.L.; Dellin, T.A.; Axness, C.L.

    1987-01-01

    Experimental data and a model to accurately and quantitatively predict the data are presented for retention of SNOS memory devices over a wide range of dose rates. A wide range of SNOS stack geometries are examined. The model is designed to aid in screening nonvolatile memories for use in a radiation environment

  6. High-performance non-volatile organic ferroelectric memory on banknotes.

    Science.gov (United States)

    Khan, M A; Bhansali, Unnat S; Alshareef, H N

    2012-04-24

    High-performance non-volatile polymer ferroelectric memory are fabricated on banknotes using poly(vinylidene fluoride trifluoroethylene). The devices show excellent performance with high remnant polarization, low operating voltages, low leakage, high mobility, and long retention times. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Phosphorene/ZnO Nano-Heterojunctions for Broadband Photonic Nonvolatile Memory Applications.

    Science.gov (United States)

    Hu, Liang; Yuan, Jun; Ren, Yi; Wang, Yan; Yang, Jia-Qin; Zhou, Ye; Zeng, Yu-Jia; Han, Su-Ting; Ruan, Shuangchen

    2018-06-10

    High-performance photonic nonvolatile memory combining photosensing and data storage with low power consumption ensures the energy efficiency of computer systems. This study first reports in situ derived phosphorene/ZnO hybrid heterojunction nanoparticles and their application in broadband-response photonic nonvolatile memory. The photonic nonvolatile memory consistently exhibits broadband response from ultraviolet (380 nm) to near infrared (785 nm), with controllable shifts of the SET voltage. The broadband resistive switching is attributed to the enhanced photon harvesting, a fast exciton separation, as well as the formation of an oxygen vacancy filament in the nano-heterojunction. In addition, the device exhibits an excellent stability under air exposure compared with reported pristine phosphorene-based nonvolatile memory. The superior antioxidation capacity is believed to originate from the fast transfer of lone-pair electrons of phosphorene. The unique assembly of phosphorene/ZnO nano-heterojunctions paves the way toward multifunctional broadband-response data-storage techniques. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effect of tunneling layers on the performances of floating-gate based organic thin-film transistor nonvolatile memories

    International Nuclear Information System (INIS)

    Wang, Wei; Han, Jinhua; Ying, Jun; Xiang, Lanyi; Xie, Wenfa

    2014-01-01

    Two types of floating-gate based organic thin-film transistor nonvolatile memories (FG-OTFT-NVMs) were demonstrated, with poly(methyl methacrylate co glycidyl methacrylate) (P(MMA-GMA)) and tetratetracontane (TTC) as the tunneling layer, respectively. Their device performances were measured and compared. In the memory with a P(MMA-GMA) tunneling layer, typical unipolar hole transport was obtained with a relatively small mobility of 0.16 cm 2 /V s. The unidirectional shift of turn-on voltage (V on ) due to only holes trapped/detrapped in/from the floating gate resulted in a small memory window of 12.5 V at programming/erasing voltages (V P /V E ) of ±100 V and a nonzero reading voltage. Benefited from the well-ordered molecule orientation and the trap-free surface of TTC layer, a considerably high hole mobility of 1.7 cm 2 /V s and a visible feature of electrons accumulated in channel and trapped in floating-gate were achieved in the memory with a TTC tunneling layer. High hole mobility resulted in a high on current and a large memory on/off ratio of 600 at the V P /V E of ±100 V. Both holes and electrons were injected into floating-gate and overwritten each other, which resulted in a bidirectional V on shift. As a result, an enlarged memory window of 28.6 V at the V P /V E of ±100 V and a zero reading voltage were achieved. Based on our results, a strategy is proposed to optimize FG-OTFT-NVMs by choosing a right tunneling layer to improve the majority carrier mobility and realize ambipolar carriers injecting and trapping in the floating-gate.

  9. Effect of tunneling layers on the performances of floating-gate based organic thin-film transistor nonvolatile memories

    Science.gov (United States)

    Wang, Wei; Han, Jinhua; Ying, Jun; Xiang, Lanyi; Xie, Wenfa

    2014-09-01

    Two types of floating-gate based organic thin-film transistor nonvolatile memories (FG-OTFT-NVMs) were demonstrated, with poly(methyl methacrylate co glycidyl methacrylate) (P(MMA-GMA)) and tetratetracontane (TTC) as the tunneling layer, respectively. Their device performances were measured and compared. In the memory with a P(MMA-GMA) tunneling layer, typical unipolar hole transport was obtained with a relatively small mobility of 0.16 cm2/V s. The unidirectional shift of turn-on voltage (Von) due to only holes trapped/detrapped in/from the floating gate resulted in a small memory window of 12.5 V at programming/erasing voltages (VP/VE) of ±100 V and a nonzero reading voltage. Benefited from the well-ordered molecule orientation and the trap-free surface of TTC layer, a considerably high hole mobility of 1.7 cm2/V s and a visible feature of electrons accumulated in channel and trapped in floating-gate were achieved in the memory with a TTC tunneling layer. High hole mobility resulted in a high on current and a large memory on/off ratio of 600 at the VP/VE of ±100 V. Both holes and electrons were injected into floating-gate and overwritten each other, which resulted in a bidirectional Von shift. As a result, an enlarged memory window of 28.6 V at the VP/VE of ±100 V and a zero reading voltage were achieved. Based on our results, a strategy is proposed to optimize FG-OTFT-NVMs by choosing a right tunneling layer to improve the majority carrier mobility and realize ambipolar carriers injecting and trapping in the floating-gate.

  10. Temozolomide Injection

    Science.gov (United States)

    ... balance or coordination fainting dizziness hair loss insomnia memory problems pain, itching, swelling, or redness in the place where the medication was injected changes in vision Some side effects can be serious. If you ...

  11. Buprenorphine Injection

    Science.gov (United States)

    ... injection is in a class of medications called opiate partial agonists. It works to prevent withdrawal symptoms ... help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, ...

  12. Risperidone Injection

    Science.gov (United States)

    ... release (long-acting) injection is used to treat schizophrenia (a mental illness that causes disturbed or unusual ... may help control your symptoms but will not cure your condition. Continue to keep appointments to receive ...

  13. Haloperidol Injection

    Science.gov (United States)

    ... haloperidol extended-release injection are used to treat schizophrenia (a mental illness that causes disturbed or unusual ... may help control your symptoms but will not cure your condition. Continue to keep appointments to receive ...

  14. Omalizumab Injection

    Science.gov (United States)

    ... injection is used to decrease the number of asthma attacks (sudden episodes of wheezing, shortness of breath, and ... about how to treat symptoms of a sudden asthma attack. If your asthma symptoms get worse or if ...

  15. Injection Tests

    CERN Document Server

    Kain, V

    2009-01-01

    The success of the start-up of the LHC on 10th of September was in part due to the preparation without beam and injection tests in 2008. The injection tests allowed debugging and improvement in appropriate portions to allow safe, efficient and state-of-the-art commissioning later on. The usefulness of such an approach for a successful start-up becomes obvious when looking at the problems we encountered before and during the injection tests and could solve during this period. The outline of the preparation and highlights of the different injection tests will be presented and the excellent performance of many tools discussed. A list of shortcomings will follow, leading to some planning for the preparation of the run in 2009.

  16. Cefotaxime Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefotaxime injection will not work for colds, flu, or other viral infections. Using ...

  17. Cefuroxime Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefuroxime injection will not work for colds, flu, or other viral infections. Using ...

  18. Doripenem Injection

    Science.gov (United States)

    ... is in a class of medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as doripenem injection will not work for colds, flu, or other viral infections. Taking ...

  19. Daptomycin Injection

    Science.gov (United States)

    ... in a class of medications called cyclic lipopeptide antibiotics. It works by killing bacteria.Antibiotics such as daptomycin injection will not work for treating colds, flu, or other viral infections. ...

  20. Ceftaroline Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftaroline injection will not work for colds, flu, or other viral infections. Using ...

  1. Aztreonam Injection

    Science.gov (United States)

    ... is in a class of medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as aztreonam injection will not work for colds, flu, or other viral infections. Taking ...

  2. Cefazolin Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefazolin injection will not work for colds, flu, or other viral infections. Taking ...

  3. Ceftazidime Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftazidime injection will not work for colds, flu, or other viral infections. Using ...

  4. Cefotetan Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefotetan injection will not work for colds, flu, or other viral infections. Using ...

  5. Cefoxitin Injection

    Science.gov (United States)

    ... is in a class of medications called cephamycin antibiotics. It works by killing bacteria.Antibiotics such as cefoxitin injection will not work for colds, flu, or other viral infections. Taking ...

  6. Tigecycline Injection

    Science.gov (United States)

    ... is in a class of medications called tetracycline antibiotics. It works by killing bacteria that cause infection.Antibiotics such as tigecycline injection will not work for colds, flu, or other viral infections. Using ...

  7. Ertapenem Injection

    Science.gov (United States)

    ... is in a class of medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as ertapenem injection will not work for colds, flu, or other viral infections. Taking ...

  8. Ceftriaxone Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftriaxone injection will not work for colds, flu, or other viral infections.Using ...

  9. Cefepime Injection

    Science.gov (United States)

    ... is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefepime injection will not work for colds, flu, or other viral infections. Using ...

  10. Telavancin Injection

    Science.gov (United States)

    ... is in a class of medications called lipoglycopeptide antibiotics. It works by killing bacteria that cause infection.Antibiotics such as telavancin injection will not work for colds, flu, or other viral infections. Using ...

  11. Doxycycline Injection

    Science.gov (United States)

    ... is in a class of medications called tetracycline antibiotics. It works by killing bacteria that cause infections.Antibiotics such as doxycycline injection will not work for colds, flu, or other viral infections. Taking ...

  12. Vancomycin Injection

    Science.gov (United States)

    ... is in a class of medications called glycopeptide antibiotics. It works by killing bacteria that cause infections.Antibiotics such as vancomycin injection will not work for colds, flu, or other viral infections. Taking ...

  13. Octreotide Injection

    Science.gov (United States)

    ... carton and protect it from light. Dispose of multi-dose vials of the immediate-release injection 14 ... and immediately place the medication in a safe location – one that is up and away and out ...

  14. Moxifloxacin Injection

    Science.gov (United States)

    ... tendon area, or inability to move or to bear weight on an affected area.Using moxifloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  15. Delafloxacin Injection

    Science.gov (United States)

    ... a tendon area, or inability to move or bear weight on an affected area.Using delafloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  16. Levofloxacin Injection

    Science.gov (United States)

    ... tendon area, or inability to move or to bear weight on an affected area.Using levofloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  17. Ciprofloxacin Injection

    Science.gov (United States)

    ... a tendon area, or inability to move or bear weight on an affected area.Using ciprofloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  18. Alirocumab Injection

    Science.gov (United States)

    ... 9 (PCSK9) inhibitor monoclonal antibodies. It works by blocking the production of LDL cholesterol in the body ... hives difficulty breathing or swallowing swelling of the face, throat, tongue, lips, and eyes Alirocumab injection may ...

  19. Evolocumab Injection

    Science.gov (United States)

    ... 9 (PCSK9) inhibitor monoclonal antibody. It works by blocking the production of LDL cholesterol in the body ... hives difficulty breathing or swallowing swelling of the face, throat, tongue, lips, and eyes Evolocumab injection may ...

  20. Acyclovir Injection

    Science.gov (United States)

    ... It is also used to treat first-time genital herpes outbreaks (a herpes virus infection that causes sores ... in the body. Acyclovir injection will not cure genital herpes and may not stop the spread of genital ...

  1. Butorphanol Injection

    Science.gov (United States)

    ... Butorphanol is in a class of medications called opioid agonist-antagonists. It works by changing the way ... suddenly stop using butorphanol injection, you may experience withdrawal symptoms such as nervousness, agitation, shakiness, diarrhea, chills, ...

  2. The influence of thickness on memory characteristic based on nonvolatile tuning behavior in poly(N-vinylcarbazole) films

    International Nuclear Information System (INIS)

    Sun, Yanmei; Ai, Chunpeng; Lu, Junguo; Li, Lei; Wen, Dianzhong; Bai, Xuduo

    2016-01-01

    The memory characteristic based on nonvolatile tuning behavior in indium tin oxide/poly(N-vinylcarbazole)/aluminum (ITO/PVK/Al) was investigated, the different memory behaviors were first observed in PVK film as the film thickness changing. By control of PVK film thickness with different spinning speeds, the nonvolatile behavior of ITO/PVK/Al sandwich structure can be tuned in a controlled manner. Obviously different nonvolatile behaviors, such as (i) flash memory behavior and (ii) write-once-read-many times (WORM) memory behavior are from the current–voltage (I–V) characteristics of the PVK films. The results suggest that the film thickness plays a key part in determining the memory type of the PVK. - Highlights: • The different memory behaviors were observed in PVK film. • The nonvolatile behavior of ITO/PVK/Al sandwich structure can be tuned. • The film thickness plays a key part in determining the memory type of the PVK.

  3. Coexistence of nonvolatility and volatility in Pt/Nb-doped SrTiO3/In memristive devices

    International Nuclear Information System (INIS)

    Yang, M; Bao, D H; Li, S W

    2013-01-01

    Memristive devices are triggering innovations in the fields of nonvolatile memory, digital logic, analogue circuits, neuromorphic engineering, and so on. Creating new memristive devices with unique characteristics would be significant for these emergent applications. Here we report the coexistence of nonvolatility and volatility in Pt/Nb-doped SrTiO 3 (NSTO)/In memristive devices. The Pt/NSTO interface contributes a nonvolatile resistive switching behaviour, whereas the NSTO/In interface displays a volatile hysteresis loop. Combining the two interfaces in the Pt/NSTO/In devices leads to the unique coexistence of nonvolatility and volatility. The results imply more opportunities to invent new memristive devices by engineering both interfaces in metal/insulator/metal structures. (paper)

  4. Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions

    Science.gov (United States)

    2017-03-06

    WP-201317) Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-volatile Particulate Matter (PM... Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions 6. AUTHOR(S) E. Corporan, M. DeWitt, C. Klingshirn, M.D. Cheng, R. Miake-Lye, J. Peck...the performance and viability of two devices to condition aircraft turbine engine exhaust to allow the accurate measurement of total (volatile and non

  5. Integration of ammonia-plasma-functionalized graphene nanodiscs as charge trapping centers for nonvolatile memory applications

    KAUST Repository

    Wang, Jer-Chyi

    2016-11-23

    Graphene nanodiscs (GNDs), functionalized using NH3 plasma, as charge trapping sites (CTSs) for non-volatile memory applications have been investigated in this study. The fabrication process relies on the patterning of Au nanoparticles (Au-NPs), whose thicknesses are tuned to adjust the GND density and size upon etching. A GND density as high as 8 × 1011 cm−2 and a diameter of approximately 20 nm are achieved. The functionalization of GNDs by NH3 plasma creates Nsingle bondH+ functional groups that act as CTSs, as observed by Raman and Fourier transform infrared spectroscopy. This inherently enhances the density of CTSs in the GNDs, as a result, the memory window becomes more than 2.4 V and remains stable after 104 operating cycles. The charge loss is less than 10% for a 10-year data retention testing, making this low-temperature process suitable for low-cost non-volatile memory applications on flexible substrates.

  6. Identifying Non-Volatile Data Storage Areas: Unique Notebook Identification Information as Digital Evidence

    Directory of Open Access Journals (Sweden)

    Nikica Budimir

    2007-03-01

    Full Text Available The research reported in this paper introduces new techniques to aid in the identification of recovered notebook computers so they may be returned to the rightful owner. We identify non-volatile data storage areas as a means of facilitating the safe storing of computer identification information. A forensic proof of concept tool has been designed to test the feasibility of several storage locations identified within this work to hold the data needed to uniquely identify a computer. The tool was used to perform the creation and extraction of created information in order to allow the analysis of the non-volatile storage locations as valid storage areas capable of holding and preserving the data created within them.  While the format of the information used to identify the machine itself is important, this research only discusses the insertion, storage and ability to retain such information.

  7. Fabrication of Nonvolatile Memory Effects in High-k Dielectric Thin Films Using Electron Irradiation

    International Nuclear Information System (INIS)

    Park, Chanrock; Cho, Daehee; Kim, Jeongeun; Hwang, Jinha

    2010-01-01

    Electron Irradiation can be applied towards nano-floating gate memories which are recognized as one of the next-generation nonvolatile memory semiconductors. NFGMs can overcome the preexisting limitations encountered in Dynamic Random Access Memories and Flash memories with the excellent advantages, i. e. high-density information storage, high response speed, high compactness, etc. The traditional nano-floating gate memories are fabricated through multi-layered nano structures of the dissimilar materials where the charge-trapping portions are sandwiched into the high-k dielectrics. However, this work reports the unique nonvolatile responses in single-layered high-k dielectric thin films if irradiated with highly accelerated electron beams. The implications of the electron irradiation will be discussed towards high-performance nano-floating gate memories

  8. Nonvolatile Memory Elements Based on the Intercalation of Organic Molecules Inside Carbon Nanotubes

    Science.gov (United States)

    Meunier, Vincent; Kalinin, Sergei V.; Sumpter, Bobby G.

    2007-02-01

    We propose a novel class of nonvolatile memory elements based on the modification of the transport properties of a conducting carbon nanotube by the presence of an encapsulated molecule. The guest molecule has two stable orientational positions relative to the nanotube that correspond to conducting and nonconducting states. The mechanism, governed by a local gating effect of the molecule on the electronic properties of the nanotube host, is studied using density functional theory. The mechanisms of reversible reading and writing of information are illustrated with a F4TCNQ molecule encapsulated inside a metallic carbon nanotube. Our results suggest that this new type of nonvolatile memory element is robust, fatigue-free, and can operate at room temperature.

  9. Performance enhancement in p-channel charge-trapping flash memory devices with Si/Ge super-lattice channel and band-to-band tunneling induced hot-electron injection

    International Nuclear Information System (INIS)

    Liu, Li-Jung; Chang-Liao, Kuei-Shu; Jian, Yi-Chuen; Wang, Tien-Ko; Tsai, Ming-Jinn

    2013-01-01

    P-channel charge-trapping flash memory devices with Si, SiGe, and Si/Ge super-lattice channel are investigated in this work. A Si/Ge super-lattice structure with extremely low roughness and good crystal structure is obtained by precisely controlling the epitaxy thickness of Ge layer. Both programming and erasing (P/E) speeds are significantly improved by employing this Si/Ge super-lattice channel. Moreover, satisfactory retention and excellent endurance characteristics up to 10 6 P/E cycles with 3.8 V memory window show that the degradation on reliability properties is negligible when super-lattice channel is introduced. - Highlights: ► A super-lattice structure is proposed to introduce more Ge content into channel. ► Super-lattice structure possesses low roughness and good crystal structure. ► P-channel flash devices with Si, SiGe, and super-lattice channel are investigated. ► Programming/erasing speeds are significantly improved. ► Reliability properties can be kept for device with super-lattice channel

  10. Preparation of NiFe binary alloy nanocrystals for nonvolatile memory applications

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this work,an idea which applies binary alloy nanocrystal floating gate to nonvolatile memory application was introduced.The relationship between binary alloy’s work function and its composition was discussed theoretically.A nanocrystal floating gate structure with NiFe nanocrystals embedded in SiO2 dielectric layers was fabricated by magnetron sputtering.The micro-structure and composition deviation of the prepared NiFe nanocrystals were also investigated by TEM and EDS.

  11. Teduglutide Injection

    Science.gov (United States)

    ... who need additional nutrition or fluids from intravenous (IV) therapy. Teduglutide injection is in a class of medications ... of the ingredients.tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking ...

  12. Dexrazoxane Injection

    Science.gov (United States)

    ... are used to treat or prevent certain side effects that may be caused by chemotherapy medications. Dexrazoxane injection (Zinecard) is used to prevent or decrease heart damage caused by doxorubicin in women who are taking the medication to treat breast cancer that has spread to other parts of the ...

  13. Triptorelin Injection

    Science.gov (United States)

    ... puberty too soon, resulting in faster than normal bone growth and development of sexual characteristics) in children 2 years and older. Triptorelin injection is in a class of medications called gonadotropin-releasing hormone (GnRH) agonists. It works by decreasing the amount ...

  14. Potential of Mass Spectrometry in Developing Clinical Laboratory Biomarkers of Nonvolatiles in Exhaled Breath.

    Science.gov (United States)

    Beck, Olof; Olin, Anna-Carin; Mirgorodskaya, Ekaterina

    2016-01-01

    Exhaled breath contains nonvolatile substances that are part of aerosol particles of submicrometer size. These particles are formed and exhaled as a result of normal breathing and contain material from distal airways of the respiratory system. Exhaled breath can be used to monitor biomarkers of both endogenous and exogenous origin and constitutes an attractive specimen for medical investigations. This review summarizes the present status regarding potential biomarkers of nonvolatile compounds in exhaled breath. The field of exhaled breath condensate is briefly reviewed, together with more recent work on more selective collection procedures for exhaled particles. The relation of these particles to the surfactant in the terminal parts of the respiratory system is described. The literature on potential endogenous low molecular weight compounds as well as protein biomarkers is reviewed. The possibility to measure exposure to therapeutic and abused drugs is demonstrated. Finally, the potential future role and importance of mass spectrometry is discussed. Nonvolatile compounds exit the lung as aerosol particles that can be sampled easily and selectively. The clinical applications of potential biomarkers in exhaled breath comprise diagnosis of disease, monitoring of disease progress, monitoring of drug therapy, and toxicological investigations. © 2015 American Association for Clinical Chemistry.

  15. Stable isotopic carbon composition of apples and their subfractions--juice, seeds, sugars, and nonvolatile acids.

    Science.gov (United States)

    Lee, H S; Wrolstad, R E

    1988-01-01

    The 13C:12C ratios of 8 authentic apple juice samples and their subfractions were determined by mass spectrometry. Apples from Argentina, Mexico, New Zealand, and the United States were processed into juice; pulp was collected from the milled fruit and seeds were collected from the press-cake. Sugars, nonvolatile acids, and phenolics were isolated from the juice by treatment with ion-exchange resins and polyvinylpyrrolidone (PVPP). The mean value for all juice samples was -24.2% which is close to the values reported by other investigators. Juice from apples grown in Argentina, Mexico, and New Zealand did not differ from U.S. samples. The isotopic composition of the subfractions ranged from -22.0 to -31.0%. The values for the pulp were essentially the same as for juice. The sugar fraction was slightly less negative than the juice; the nonvolatile acid and phenolic fractions were more negative. The levels of nonvolatile acids and phenolics in apple juice are low, however, so these compounds contribute little to overall delta 13C values in juice.

  16. Evaluation of reinitialization-free nonvolatile computer systems for energy-harvesting Internet of things applications

    Science.gov (United States)

    Onizawa, Naoya; Tamakoshi, Akira; Hanyu, Takahiro

    2017-08-01

    In this paper, reinitialization-free nonvolatile computer systems are designed and evaluated for energy-harvesting Internet of things (IoT) applications. In energy-harvesting applications, as power supplies generated from renewable power sources cause frequent power failures, data processed need to be backed up when power failures occur. Unless data are safely backed up before power supplies diminish, reinitialization processes are required when power supplies are recovered, which results in low energy efficiencies and slow operations. Using nonvolatile devices in processors and memories can realize a faster backup than a conventional volatile computer system, leading to a higher energy efficiency. To evaluate the energy efficiency upon frequent power failures, typical computer systems including processors and memories are designed using 90 nm CMOS or CMOS/magnetic tunnel junction (MTJ) technologies. Nonvolatile ARM Cortex-M0 processors with 4 kB MRAMs are evaluated using a typical computing benchmark program, Dhrystone, which shows a few order-of-magnitude reductions in energy in comparison with a volatile processor with SRAM.

  17. Overview of one transistor type of hybrid organic ferroelectric non-volatile memory

    Institute of Scientific and Technical Information of China (English)

    Young; Tea; Chun; Daping; Chu

    2015-01-01

    Organic ferroelectric memory devices based on field effect transistors that can be configured between two stable states of on and off have been widely researched as the next generation data storage media in recent years.This emerging type of memory devices can lead to a new instrument system as a potential alternative to previous non-volatile memory building blocks in future processing units because of their numerous merits such as cost-effective process,simple structure and freedom in substrate choices.This bi-stable non-volatile memory device of information storage has been investigated using several organic or inorganic semiconductors with organic ferroelectric polymer materials.Recent progresses in this ferroelectric memory field,hybrid system have attracted a lot of attention due to their excellent device performance in comparison with that of all organic systems.In this paper,a general review of this type of ferroelectric non-volatile memory is provided,which include the device structure,organic ferroelectric materials,electrical characteristics and working principles.We also present some snapshots of our previous study on hybrid ferroelectric memories including our recent work based on zinc oxide nanowire channels.

  18. Nonvolatile resistive switching in Pt/laALO3/srTiO3 heterostructures

    KAUST Repository

    Wu, S.

    2013-12-12

    Resistive switching heterojunctions, which are promising for nonvolatile memory applications, usually share a capacitorlike metal-oxide-metal configuration. Here, we report on the nonvolatile resistive switching in Pt/LaAlO3/SrTiO3 heterostructures, where the conducting layer near the LaAlO3/SrTiO3 interface serves as the "unconventional"bottom electrode although both oxides are band insulators. Interestingly, the switching between low-resistance and high-resistance states is accompanied by reversible transitions between tunneling and Ohmic characteristics in the current transport perpendicular to the planes of the heterojunctions. We propose that the observed resistive switching is likely caused by the electric-field-induced drift of charged oxygen vacancies across the LaAlO3/SrTiO3 interface and the creation of defect-induced gap states within the ultrathin LaAlO3 layer. These metal-oxide-oxide heterojunctions with atomically smooth interfaces and defect-controlled transport provide a platform for the development of nonvolatile oxide nanoelectronics that integrate logic and memory devices.

  19. Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

    Directory of Open Access Journals (Sweden)

    M. S. T. Barroso

    2011-06-01

    Full Text Available Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa, whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa. The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

  20. Nonvolatile Resistive Switching in Pt/LaAlO_{3}/SrTiO_{3} Heterostructures

    Directory of Open Access Journals (Sweden)

    Shuxiang Wu

    2013-12-01

    Full Text Available Resistive switching heterojunctions, which are promising for nonvolatile memory applications, usually share a capacitorlike metal-oxide-metal configuration. Here, we report on the nonvolatile resistive switching in Pt/LaAlO_{3}/SrTiO_{3} heterostructures, where the conducting layer near the LaAlO_{3}/SrTiO_{3} interface serves as the “unconventional” bottom electrode although both oxides are band insulators. Interestingly, the switching between low-resistance and high-resistance states is accompanied by reversible transitions between tunneling and Ohmic characteristics in the current transport perpendicular to the planes of the heterojunctions. We propose that the observed resistive switching is likely caused by the electric-field-induced drift of charged oxygen vacancies across the LaAlO_{3}/SrTiO_{3} interface and the creation of defect-induced gap states within the ultrathin LaAlO_{3} layer. These metal-oxide-oxide heterojunctions with atomically smooth interfaces and defect-controlled transport provide a platform for the development of nonvolatile oxide nanoelectronics that integrate logic and memory devices.

  1. Physical principles and current status of emerging non-volatile solid state memories

    Science.gov (United States)

    Wang, L.; Yang, C.-H.; Wen, J.

    2015-07-01

    Today the influence of non-volatile solid-state memories on persons' lives has become more prominent because of their non-volatility, low data latency, and high robustness. As a pioneering technology that is representative of non-volatile solidstate memories, flash memory has recently seen widespread application in many areas ranging from electronic appliances, such as cell phones and digital cameras, to external storage devices such as universal serial bus (USB) memory. Moreover, owing to its large storage capacity, it is expected that in the near future, flash memory will replace hard-disk drives as a dominant technology in the mass storage market, especially because of recently emerging solid-state drives. However, the rapid growth of the global digital data has led to the need for flash memories to have larger storage capacity, thus requiring a further downscaling of the cell size. Such a miniaturization is expected to be extremely difficult because of the well-known scaling limit of flash memories. It is therefore necessary to either explore innovative technologies that can extend the areal density of flash memories beyond the scaling limits, or to vigorously develop alternative non-volatile solid-state memories including ferroelectric random-access memory, magnetoresistive random-access memory, phase-change random-access memory, and resistive random-access memory. In this paper, we review the physical principles of flash memories and their technical challenges that affect our ability to enhance the storage capacity. We then present a detailed discussion of novel technologies that can extend the storage density of flash memories beyond the commonly accepted limits. In each case, we subsequently discuss the physical principles of these new types of non-volatile solid-state memories as well as their respective merits and weakness when utilized for data storage applications. Finally, we predict the future prospects for the aforementioned solid-state memories for

  2. Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China

    Directory of Open Access Journals (Sweden)

    H. H. Y. Cheung

    2016-07-01

    Full Text Available Simultaneous measurements of aerosol volatility and carbonaceous matters were conducted at a suburban site in Guangzhou, China, in February and March 2014 using a volatility tandem differential mobility analyzer (VTDMA and an organic carbon/elemental carbon (OC ∕ EC analyzer. Low volatility (LV particles, with a volatility shrink factor (VSF at 300 °C exceeding 0.9, contributed 5 % of number concentrations of the 40 nm particles and 11–15 % of the 80–300 nm particles. They were composed of non-volatile material externally mixed with volatile material, and therefore did not evaporate significantly at 300 °C. Non-volatile material mixed internally with the volatile material was referred to as medium volatility (MV, 0.4  <  VSF  <  0.9 and high volatility (HV, VSF  <  0.4 particles. The MV and HV particles contributed 57–71 % of number concentration for the particles between 40 and 300 nm in size. The average EC and OC concentrations measured by the OC ∕ EC analyzer were 3.4 ± 3.0 and 9.0 ± 6.0 µg m−3, respectively. Non-volatile OC evaporating at 475 °C or above, together with EC, contributed 67 % of the total carbon mass. In spite of the daily maximum and minimum, the diurnal variations in the volume fractions of the volatile material, HV, MV and LV residuals were less than 15 % for the 80–300 nm particles. Back trajectory analysis also suggests that over 90 % of the air masses influencing the sampling site were well aged as they were transported at low altitudes (below 1500 m for over 40 h before arrival. Further comparison with the diurnal variations in the mass fractions of EC and the non-volatile OC in PM2.5 suggests that the non-volatile residuals may be related to both EC and non-volatile OC in the afternoon, during which the concentration of aged organics increased. A closure analysis of the total mass of LV and MV residuals and the mass of EC or the

  3. Determination of non-volatile radiolytic compounds in ethylene co-vinyl alcohol

    International Nuclear Information System (INIS)

    Kothapalli, A.; Sadler, G.

    2003-01-01

    The use of ionizing radiation on food contact polymers is increasing due to the critical role of the package in holding or containing the irradiated foods [Food Add. Contam. 18(6) (2001) 475]. Irradiation benefits the food if properly applied and the food is pre-packaged prior to irradiation to protect it from subsequent recontamination. The United States Food and Drug Administration (USFDA) has approved the use of ionizing radiation within the dosage range of 0-60 kGy on limited films since the 1960s [USFDA 21CFR 179.45]. The obstacle in the way of approval of additional polymers is that FDA fears that these materials may undergo changes during irradiation producing toxic radiolytic fragments. Ethylene co-vinyl alcohol (EVOH), which is often used in food applications, is not approved by the FDA for pre-packaged irradiated foods. The present work examines the non-volatile radiolytic compounds, which may be formed due to exposure to gamma irradiation at the dosage levels of 3 and 10 kGy versus a non-radiated control. Irradiated EVOH is subjected to extraction with 95:5 ethanol and water (by volume) as the food simulating solvent (FSS) for a period of 10 days at 40 deg. C, which models the amount of radiolytic compound a food would extract in 1 year [USFDA Chemistry Requirement for Food Contact Notification]. The FSS is then analyzed for the presence of non-volatile compounds using advanced liquid chromatographic techniques. The chromatograms obtained from different dosages show that non-volatile radiolytic compounds are not formed in EVOH and it would, therefore be in compliance with safety demands of USFDA [Available at: http://www.cfsan.fda.gov/~dms/opa-guid.htmlref and http://www.access.gpo.gov/nara/cfr/cfr-table-search.htmlpage1

  4. ZnO as dielectric for optically transparent non-volatile memory

    International Nuclear Information System (INIS)

    Salim, N. Tjitra; Aw, K.C.; Gao, W.; Wright, Bryon E.

    2009-01-01

    This paper discusses the application of a DC sputtered ZnO thin film as a dielectric in an optically transparent non-volatile memory. The main motivation for using ZnO as a dielectric is due to its optical transparency and mechanical flexibility. We have established the relationship between the electrical resistivity (ρ) and the activation energy (E a ) of the electron transport in the conduction band of the ZnO film. The ρ of 2 x 10 4 -5 x 10 7 Ω-cm corresponds to E a of 0.36-0.76 eV, respectively. The k-value and optical band-gap for films sputtered with Ar:O 2 ratio of 4:1 are 53 ± 3.6 and 3.23 eV, respectively. In this paper, the basic charge storage element for a non-volatile memory is a triple layer dielectric structure in which a 50 nm thick ZnO film is sandwiched between two layers of methyl silsesquioxane sol-gel dielectric of varying thickness. A pronounced clockwise capacitance-voltage (C-V) hysteresis was observed with a memory window of 6 V. The integration with a solution-processable pentacene, 13,6-N-Sulfinylacetamodipentacene resulted in an optically transparent organic field effect transistor non-volatile memory (OFET-NVM). We have demonstrated that this OFET-NVM can be electrically programmed and erased at low voltage (± 10 V) with a threshold voltage shift of 4.0 V.

  5. Characteristics of a non-volatile liquid propellant in liquid-fed ablative pulsed plasma thrusters

    Science.gov (United States)

    Ling, William Yeong Liang; Schönherr, Tony; Koizumi, Hiroyuki

    2017-02-01

    In the past several decades, the use of electric propulsion in spacecraft has experienced tremendous growth. With the increasing adoption of small satellites in the kilogram range, suitable propulsion systems will be necessary in the near future. Pulsed plasma thrusters (PPTs) were the first form of electric propulsion to be deployed in orbit, and are highly suitable for small satellites due to their inherent simplicity. However, their lifetime is limited by disadvantages such as carbon deposition leading to thruster failure, and complicated feeding systems required due to the conventional use of solid propellants (usually polytetrafluoroethylene (PTFE)). A promising alternative to solid propellants has recently emerged in the form of non-volatile liquids that are stable in vacuum. This study presents a broad comparison of the non-volatile liquid perfluoropolyether (PFPE) and solid PTFE as propellants on a PPT with a common design base. We show that liquid PFPE can be successfully used as a propellant, and exhibits similar plasma discharge properties to conventional solid PTFE, but with a mass bit that is an order of magnitude higher for an identical ablation area. We also demonstrate that the liquid PFPE propellant has exceptional resistance to carbon deposition, completely negating one of the major causes of thruster failure, while solid PTFE exhibited considerable carbon build-up. Energy dispersive X-ray spectroscopy was used to examine the elemental compositions of the surface deposition on the electrodes and the ablation area of the propellant (or PFPE encapsulator). The results show that based on its physical characteristics and behavior, non-volatile liquid PFPE is an extremely promising propellant for use in PPTs, with an extensive scope available for future research and development.

  6. Zinc Cadmium Selenide Cladded Quantum Dot Based Electroluminescent and Nonvolatile Memory Devices

    Science.gov (United States)

    Al-Amody, Fuad H.

    This dissertation presents electroluminescent (EL) and nonvolatile memory devices fabricated using pseudomorphic ZnCdSe-based cladded quantum dots (QDs). These dots were grown using our own in-school built novel reactor. The EL device was fabricated on a substrate of ITO (indium tin oxide) coated glass with the quantum dots sandwiched between anode and cathode contacts with a small barrier layer on top of the QDs. The importance of these cladded dots is to increase the quantum yield of device. This device is unique as they utilize quantum dots that are pseudomorphic (nearly lattice-matched core and the shell of the dot). In the case of floating quantum dot gate nonvolatile memory, cladded ZnCdSe quantum dots are deposited on single crystalline gate insulator (ZnMgS/ZnMgSe), which is grown using metal-organic chemical vapor deposition (MOCVD). The control gate dielectric layer of the nonvolatile memory is Si3N4 or SiO2 and is grown using plasma enhanced chemical vapor deposition (PECVD). The cladded dots are grown using an improved methodology of photo-assisted microwave plasma metal-organic chemical vapor deposition (PMP-MOCVD) enhanced reactor. The cladding composition of the core and shell of the dots was engineered by the help of ultraviolet light which changed the incorporation of zinc (and hence composition of ZnCdSe). This makes ZnxCd1--xSe-ZnyCd1--y Se QDs to have a low composition of zinc in the core than the cladding (x

  7. Determination of non-volatile radiolytic compounds in ethylene co-vinyl alcohol

    Science.gov (United States)

    Kothapalli, A.; Sadler, G.

    2003-08-01

    The use of ionizing radiation on food contact polymers is increasing due to the critical role of the package in holding or containing the irradiated foods [Food Add. Contam. 18(6) (2001) 475]. Irradiation benefits the food if properly applied and the food is pre-packaged prior to irradiation to protect it from subsequent recontamination. The United States Food and Drug Administration (USFDA) has approved the use of ionizing radiation within the dosage range of 0-60 kGy on limited films since the 1960s [USFDA 21CFR 179.45]. The obstacle in the way of approval of additional polymers is that FDA fears that these materials may undergo changes during irradiation producing toxic radiolytic fragments. Ethylene co-vinyl alcohol (EVOH), which is often used in food applications, is not approved by the FDA for pre-packaged irradiated foods. The present work examines the non-volatile radiolytic compounds, which may be formed due to exposure to gamma irradiation at the dosage levels of 3 and 10 kGy versus a non-radiated control. Irradiated EVOH is subjected to extraction with 95:5 ethanol and water (by volume) as the food simulating solvent (FSS) for a period of 10 days at 40 °C, which models the amount of radiolytic compound a food would extract in 1 year [USFDA Chemistry Requirement for Food Contact Notification]. The FSS is then analyzed for the presence of non-volatile compounds using advanced liquid chromatographic techniques. The chromatograms obtained from different dosages show that non-volatile radiolytic compounds are not formed in EVOH and it would, therefore be in compliance with safety demands of USFDA [Available at: http://www.cfsan.fda.gov/~dms/opa-guid.html#ref and http://www.access.gpo.gov/nara/cfr/cfr-table-search.html#page1].

  8. Release and nonvolatile operation of carbon nanotube nanorelay by resonant vibration

    Energy Technology Data Exchange (ETDEWEB)

    Kagota, Tatsuya; Takei, Kuniharu; Arie, Takayuki; Akita, Seiji, E-mail: akita@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531 (Japan); Nagataki, Atsuko [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531 (Japan); Materials Analysis Research Center, KRI, Inc., Osaka 554-0051 (Japan)

    2013-11-11

    We investigated the release of a stuck carbon nanotube (CNT) cantilever beam in nanorelay applications using a nano-manipulator. Even with strong adhesion induced by electrostatic attraction that is 100 times stronger than the van der Waals interaction, successful release of a nanotube arm from a stuck state was realized by the application of a resonant vibration to the stuck CNT arm. Furthermore, nonvolatile operation of the nanotube nanorelay was demonstrated by the application of the resonant vibration to the stuck CNT arm.

  9. Investigation of non-volatile additives on the process of distillation of hydrocarbon mixtures

    Directory of Open Access Journals (Sweden)

    М.Б. Степанов

    2009-02-01

    Full Text Available  The given results of researches of influence of nonvolatile additives on processes of distillation of individual hydrocarbons and their mixes, including petroleum and mineral oil. With the help of the developed computer system of the continuous control of distillation it is shown, that at the presence of small amounts of the additive decrease of temperature of the beginning of boiling of hydrocarbons is observed, their speeds of banish and exits of light fuel mineral oil grow during initial oil refining

  10. Fabrication of Pb (Zr, Ti) O3 Thin Film for Non-Volatile Memory Device Application

    International Nuclear Information System (INIS)

    Mar Lar Win

    2011-12-01

    Ferroelectric lead zirconate titanate powder was composed of mainly the oxides of titanium, zirconium and lead. PZT powder was firstly prepared by thermal synthesis at different Zr/Ti ratios with various sintering temperatures. PZT thin film was fabricated on SiO2/Si substrate by using thermal evaporation method. Physical and elemental analysis were carried out by using SEM, EDX and XRD The ferroelectric properties and the switching behaviour of the PZT thin films were investigated. The ferroelectric properties and switching properties of the PZT thin film (near morphotropic phase boundary sintered at 800 C) could function as a nonvolatile memory.

  11. Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory

    Science.gov (United States)

    Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

    2012-01-01

    Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic. PMID:22900143

  12. Overview of radiation effects on emerging non-volatile memory technologies

    Directory of Open Access Journals (Sweden)

    Fetahović Irfan S.

    2017-01-01

    Full Text Available In this paper we give an overview of radiation effects in emergent, non-volatile memory technologies. Investigations into radiation hardness of resistive random access memory, ferroelectric random access memory, magneto-resistive random access memory, and phase change memory are presented in cases where these memory devices were subjected to different types of radiation. The obtained results proved high radiation tolerance of studied devices making them good candidates for application in radiation-intensive environments. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 171007

  13. High-Speed Non-Volatile Optical Memory: Achievements and Challenges

    Directory of Open Access Journals (Sweden)

    Vadym Zayets

    2017-01-01

    Full Text Available We have proposed, fabricated, and studied a new design of a high-speed optical non-volatile memory. The recoding mechanism of the proposed memory utilizes a magnetization reversal of a nanomagnet by a spin-polarized photocurrent. It was shown experimentally that the operational speed of this memory may be extremely fast above 1 TBit/s. The challenges to realize both a high-speed recording and a high-speed reading are discussed. The memory is compact, integratable, and compatible with present semiconductor technology. If realized, it will advance data processing and computing technology towards a faster operation speed.

  14. Microwave oven fabricated hybrid memristor devices for non-volatile memory storage

    International Nuclear Information System (INIS)

    Verrelli, E; Gray, R J; O’Neill, M; Kemp, N T; Kelly, S M

    2014-01-01

    Novel hybrid non-volatile memories made using an ultra-fast microwave heating method are reported for the first time. The devices, consisting of aligned ZnO nanorods embedded in poly (methyl methacrylate), require no forming step and exhibit reliable and reproducible bipolar resistive switching at low voltages and with low power usage. We attribute these properties to a combination of the high aspect ratio of the nanorods and the polymeric hybrid structure of the device. The extremely easy, fast and low-cost solution based method of fabrication makes possible the simple and quick production of cheap memory cells. (paper)

  15. Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory

    International Nuclear Information System (INIS)

    Han, Jinhua; Wang, Wei; Ying, Jun; Xie, Wenfa

    2014-01-01

    An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized

  16. Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jinhua; Wang, Wei, E-mail: wwei99@jlu.edu.cn; Ying, Jun; Xie, Wenfa [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2014-01-06

    An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized.

  17. Excitation spectra and forward injection electroluminescence of Er/sup 3+/ ions in ZnS

    International Nuclear Information System (INIS)

    Jiaqi, Y.; Tianren, Z.; Wenlian, L.

    1985-01-01

    Trivalent rare earth ions (RE/sup 3+/) are efficient luminescent centers for electroluminescence (EL) of thin films of II-VI compounds, which are promising display materials and attract more and more attention. The mechanism of all EL devices of RE/sup 3+/ available so far is hot electron impact excitation. Based on the analysis of excitation spectra of RE/sup 3+/ in ZnS, the authors have pointed out the possibility of a new type of EL of RE/sup 3+/ - forward injection EL, which have potential of reducing operation voltage and raising efficiency. The forward injection EL of RE/sup 3+/ has been observed and experimentally proven in ZnS:Er/sup 3+/ diode for the first time

  18. Safe injection procedures, injection practices, and needlestick ...

    African Journals Online (AJOL)

    Results: Safe injection procedures regarding final waste disposal were sufficiently adopted, while measures regarding disposable injection equipment, waste containers, hand hygiene, as well as injection practices were inadequately carried out. Lack of job aid posters that promote safe injection and safe disposal of ...

  19. Future Trend of Non-Volatile Semiconductor Memory and Feasibility Study of BiCS Type Stacked Structure

    OpenAIRE

    渡辺, 重佳

    2009-01-01

    Future trend of non-volatile semiconductor memory—FeRAM, MRAM, PRAM, ReRAM—compared with NAND typeflash memory has been described based on its history, application and performance. In the realistic point of view,FeRAM and MRAM are suitable for embedded memory and main memory, and PRAM and ReRAM are promising candidatesfor main memory and mass-storage memory for multimedia. Furthermore, the feasibility study of aggressiveultra-low-cost high-speed universal non-volatile semiconductor memory has...

  20. Nonvolatile rewritable memory device based on solution-processable graphene/poly(3-hexylthiophene) nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Li, E-mail: lizhang9@zzu.edu.cn [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052 (China); Li, Ye; Shi, Jun [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052 (China); Shi, Gaoquan [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Cao, Shaokui, E-mail: Caoshaokui@zzu.edu.cn [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052 (China)

    2013-11-01

    An electrically bistable device utilizing a nanocomposite of hexadecylamine-functionalized graphene oxide (HDAGO) with poly(3-hexylthiophene) (P3HT) is demonstrated. The device has an ITO/P3HT-HDAGO/Al sandwich structure, in which the composite film of P3HT-HDAGO was prepared by simple solution phase mixing of the exfoliated HDAGO monolayers with P3HT matrix and a spin-coating method. The memory device exhibits typical bistable electrical switching behavior and a nonvolatile rewritable memory effect, with a turn-on voltage of about 1.5 V and an ON/OFF-state current ratio of 10{sup 5}. Under ambient conditions, both the ON and OFF states are stable under a constant voltage stress or a continuous pulse voltage stress at a read voltage of 1 V. The conduction mechanism is deduced from the modeling of the nature of currents in both states, and the electrical switching behavior can be attributed to the electric-field-induced charge transfer between P3HT and HDAGO nanosheets. - Highlights: • Nonvolatile rewritable memory effect in P3HT–graphene composite is demonstrated. • The memory device was fabricated through a simple solution processing technique. • The device shows a remarkable electrical bistable behavior and excellent stability. • Memory mechanism is deduced from the modeling of the currents in both states.

  1. Review on Physically Flexible Nonvolatile Memory for Internet of Everything Electronics

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-07-23

    Solid-state memory is an essential component of the digital age. With advancements in healthcare technology and the Internet of Things (IoT), the demand for ultra-dense, ultra-low-power memory is increasing. In this review, we present a comprehensive perspective on the most notable approaches to the fabrication of physically flexible memory devices. With the future goal of replacing traditional mechanical hard disks with solid-state storage devices, a fully flexible electronic system will need two basic devices: transistors and nonvolatile memory. Transistors are used for logic operations and gating memory arrays, while nonvolatile memory (NVM) devices are required for storing information in the main memory and cache storage. Since the highest density of transistors and storage structures is manifested in memories, the focus of this review is flexible NVM. Flexible NVM components are discussed in terms of their functionality, performance metrics, and reliability aspects, all of which are critical components for NVM technology to be part of mainstream consumer electronics, IoT, and advanced healthcare devices. Finally, flexible NVMs are benchmarked and future prospects are provided.

  2. Migration of residual nonvolatile and inorganic compounds from recycled post-consumer PET and HDPE

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, Camila; Reyes, Felix G.R., E-mail: reyesfgr@fea.unicamp.br [Universidade de Campinas (UNICAMP), SP (Brazil). Escola de Engenharia dos Alimentos. Dept. de Ciencias dos Alimentos; Freire, Maria Teresa de A. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Fac. de Ciencia Animal e Engenharia dos Alimentos. Dept. de Engenharia dos Alimentos; Nerin, Cristina; Bentayeb, Karim; Rodriguez-Lafuente, Angel; Aznar, Margarita [Dept. of Analytical Chemistry, Arago Inst. of Engineering Research, University of Zaragoza (Spain)

    2014-04-15

    Migration of nonvolatile and inorganic residual compounds from post-consumer recycled polyethylene terephthalate (PET) submitted to cleaning processes for subsequent production of materials intended to food contact, as well as from multilayer packaging material containing post-consumer recycled high-density polyethylene (HDPE) was determined. Tests were carried out using food simulant. Nonvolatile organic contaminants from PET, determined by liquid chromatography-mass spectrometry (UPLC-QqQ/MS), showed significant migration reduction as consequence of the more complex cleaning technologies applied. However, contaminants not allowed by Brazilian and European Union regulations were identified even in deep cleaning samples. Results from multilayer HDPE showed a greater number of contaminants when compared to recycled pellets. Inorganic contaminants, determined by inductively coupled plasma mass spectrometry were below the acceptable levels. Additional studies for identification and quantitation of unknown molecules which were not possible to identify in this study by UPLC-QqQ/MS are required to ascertain the safety of using post-consumer recycled packaging material. (author)

  3. Review on Physically Flexible Nonvolatile Memory for Internet of Everything Electronics

    Directory of Open Access Journals (Sweden)

    Mohamed T. Ghoneim

    2015-07-01

    Full Text Available Solid-state memory is an essential component of the digital age. With advancements in healthcare technology and the Internet of Things (IoT, the demand for ultra-dense, ultra-low-power memory is increasing. In this review, we present a comprehensive perspective on the most notable approaches to the fabrication of physically flexible memory devices. With the future goal of replacing traditional mechanical hard disks with solid-state storage devices, a fully flexible electronic system will need two basic devices: transistors and nonvolatile memory. Transistors are used for logic operations and gating memory arrays, while nonvolatile memory (NVM devices are required for storing information in the main memory and cache storage. Since the highest density of transistors and storage structures is manifested in memories, the focus of this review is flexible NVM. Flexible NVM components are discussed in terms of their functionality, performance metrics, and reliability aspects, all of which are critical components for NVM technology to be part of mainstream consumer electronics, IoT, and advanced healthcare devices. Finally, flexible NVMs are benchmarked and future prospects are provided.

  4. Properties of nonvolatile and antibacterial bioboard produced from bamboo macromolecules by hot pressing

    Directory of Open Access Journals (Sweden)

    Shengbo Ge

    2018-03-01

    Full Text Available Employing the antibacterial property of industrial bamboo vinegar (IBV and the photocatalytic degradation of TiO2, bamboo macromolecules were pretreated and processed into nonvolatile and antibacterial bio board (NVABB. The NVABB was then analyzed by conducting Fourier-transform infrared spectroscopy, thermogravimetric analysis and differential thermal analysis. Results show that NVABB samples had average density of 0.96 g/cm3, which is appropriate for application. In terms of physical and mechanical properties, the best NVABB sample obtained from IBV, TiO2 and bamboo had an IBV pretreatment time of 10 min, 2% TiO2 and 1% bamboo charcoal. Fourier-transform infrared spectroscopy demonstrated that optimum conditions for hot pressing were a temperature of 170 °C, duration of 15 min and the addition of IBV and TiO2. Thermogravimetric analysis/differential thermal analysis curves suggest that the thermal degradation of NVABB was less than that of bamboo and that hot pressing obviously increased the thermal stability of HDBB samples. Analysis of the antimicrobial effect revealed that IBV pretreatment improves the antibacterial property of NVABB. Keywords: Industrial bamboo vinegar, Nonvolatile and antibacterial bio board, Bamboo macromolecules, Fourier-transform infrared spectroscopy, Thermogravimetric analysis/differential thermal analysis

  5. Interlaboratory study of a method for determining nonvolatile organic carbon in aquifer materials

    Science.gov (United States)

    Caughey, M.E.; Barcelona, M.J.; Powell, R.M.; Cahill, R.A.; Gron, C.; Lawrenz, D.; Meschi, P.L.

    1995-01-01

    The organic carbon fraction in aquifer materials exerts a major influence on the subsurface mobilities of organic and organic-associated contaminants. The spatial distribution of total organic carbon (TOC) in aquifer materials must be determined before the transport of hydrophobic organic pollutants in aquifers can be modeled accurately. Previous interlaboratory studies showed that it is difficult to measure TOC concentrations 1%. We have tested a new analytical method designed to improve the accuracy and precision of nonvolatile TOC quantitation in geologic materials that also contain carbonate minerals. Four authentic aquifer materials and one NIST standard reference material were selected as test materials for a blind collaborative study. Nonvolatile TOC in these materials ranged from 0.05 to 1.4%, while TIC ranged from 0.46 to 12.6%. Sample replicates were digested with sulfurous acid, dried at 40??C, and then combusted at 950??C using LECO or UIC instruments. For the three test materials that contained >2% TIC, incomplete acidification resulted in a systematic positive bias of TOC values reported by five of the six laboratories that used the test method. Participants did not have enough time to become proficient with the new method before they analyzed the test materials. A seventh laboratory successfully used an alternative method that analyzed separate liquid and solid fractions of the acidified sample residues. ?? 1995 Springer-Verlag.

  6. Design exploration of emerging nano-scale non-volatile memory

    CERN Document Server

    Yu, Hao

    2014-01-01

    This book presents the latest techniques for characterization, modeling and design for nano-scale non-volatile memory (NVM) devices.  Coverage focuses on fundamental NVM device fabrication and characterization, internal state identification of memristic dynamics with physics modeling, NVM circuit design, and hybrid NVM memory system design-space optimization. The authors discuss design methodologies for nano-scale NVM devices from a circuits/systems perspective, including the general foundations for the fundamental memristic dynamics in NVM devices.  Coverage includes physical modeling, as well as the development of a platform to explore novel hybrid CMOS and NVM circuit and system design.   • Offers readers a systematic and comprehensive treatment of emerging nano-scale non-volatile memory (NVM) devices; • Focuses on the internal state of NVM memristic dynamics, novel NVM readout and memory cell circuit design, and hybrid NVM memory system optimization; • Provides both theoretical analysis and pr...

  7. A review of emerging non-volatile memory (NVM) technologies and applications

    Science.gov (United States)

    Chen, An

    2016-11-01

    This paper will review emerging non-volatile memory (NVM) technologies, with the focus on phase change memory (PCM), spin-transfer-torque random-access-memory (STTRAM), resistive random-access-memory (RRAM), and ferroelectric field-effect-transistor (FeFET) memory. These promising NVM devices are evaluated in terms of their advantages, challenges, and applications. Their performance is compared based on reported parameters of major industrial test chips. Memory selector devices and cell structures are discussed. Changing market trends toward low power (e.g., mobile, IoT) and data-centric applications create opportunities for emerging NVMs. High-performance and low-cost emerging NVMs may simplify memory hierarchy, introduce non-volatility in logic gates and circuits, reduce system power, and enable novel architectures. Storage-class memory (SCM) based on high-density NVMs could fill the performance and density gap between memory and storage. Some unique characteristics of emerging NVMs can be utilized for novel applications beyond the memory space, e.g., neuromorphic computing, hardware security, etc. In the beyond-CMOS era, emerging NVMs have the potential to fulfill more important functions and enable more efficient, intelligent, and secure computing systems.

  8. Review on Physically Flexible Nonvolatile Memory for Internet of Everything Electronics

    KAUST Repository

    Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

    2015-01-01

    Solid-state memory is an essential component of the digital age. With advancements in healthcare technology and the Internet of Things (IoT), the demand for ultra-dense, ultra-low-power memory is increasing. In this review, we present a comprehensive perspective on the most notable approaches to the fabrication of physically flexible memory devices. With the future goal of replacing traditional mechanical hard disks with solid-state storage devices, a fully flexible electronic system will need two basic devices: transistors and nonvolatile memory. Transistors are used for logic operations and gating memory arrays, while nonvolatile memory (NVM) devices are required for storing information in the main memory and cache storage. Since the highest density of transistors and storage structures is manifested in memories, the focus of this review is flexible NVM. Flexible NVM components are discussed in terms of their functionality, performance metrics, and reliability aspects, all of which are critical components for NVM technology to be part of mainstream consumer electronics, IoT, and advanced healthcare devices. Finally, flexible NVMs are benchmarked and future prospects are provided.

  9. Volatiles and Nonvolatiles in Flourensia campestris Griseb. (Asteraceae), How Much Do Capitate Glandular Trichomes Matter?

    Science.gov (United States)

    Piazza, Leonardo A; López, Daniela; Silva, Mariana P; López Rivilli, Marisa J; Tourn, Mónica G; Cantero, Juan J; Scopel, Ana L

    2018-03-01

    The distribution and ultrastructure of capitate glandular trichomes (GTs) in Flourensia species (Asteraceae) have been recently elucidated, but their metabolic activity and potential biological function remain unexplored. Selective nonvolatile metabolites from isolated GTs were strikingly similar to those found on leaf surfaces. The phytotoxic allelochemical sesquiterpene (-)-hamanasic acid A ((-)-HAA) was the major constituent (ca. 40%) in GTs. Although GTs are quaternary ammonium compounds (QACs)-accumulating species, glycine betaine was not found in GTs; it was only present in the leaf mesophyll. Two (-)-HAA accompanying surface secreted products: compounds 4-hydroxyacetophenone (piceol; 1) and 2-hydroxy-5-methoxyacetophenone (2), which were isolated and fully characterized (GC/MS, NMR), were present in the volatiles found in GTs. The essential oils of fresh leaves revealed ca. 33% monoterpenes, 26% hydrocarbon- and 30% oxygenated sesquiterpenes, most of them related to cadinene and bisabolene derivatives. Present results suggest a main role of GTs in determining the volatile and nonvolatile composition of F. campestris leaves. Based on the known activities of the compounds identified, it can be suggested that GTs in F. campestris would play key ecological functions in plant-pathogen and plant-plant interactions. In addition, the strikingly high contribution of compounds derived from cadinene and bisabolene pathways, highlights the potential of this species as a source of high-valued bioproducts. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  10. Negative effect of Au nanoparticles on an IGZO TFT-based nonvolatile memory device

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Myunghoon; Yoo, Gwangwe; Lee, Jongtaek; Jeong, Seokwon; Roh, Yonghan; Park, Jinhong; Kwon, Namyong [Sungkyunkwan University, Suwon (Korea, Republic of); Jung, Wooshik [Stanford University, Stanford, CA (United States)

    2014-02-15

    In this letter, the electrical characteristics of nonvolatile memory devices based on back gate type indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) are investigated in terms of the Au nanoparticles (NPs) employed in the floating gate-stack of the device. The size of the Au NPs is controlled using a by 500 .deg. C annealing process after the Au thin-film deposition. The size and the roughness of the Au NPs were observed by using scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. In order to analyze the electrical properties according to Au NP size, we measured the current-voltage (I{sub D}-V{sub G}) characteristics of the nonvolatile memory devices fabricated without Au NPs and with Au NPs of various sizes. The size of the Au NP increased, so did the surface roughness of the gate. This resulted in increased carrier scattering, which subsequently degraded the on-current of the memory device. In addition, inter-diffusion between the Au and the α-IGZO through the non-uniform Al{sub 2}O{sub 3} tunneling layer seemed to further degrade the device performance.

  11. Non-volatile flash memory with discrete bionanodot floating gate assembled by protein template

    International Nuclear Information System (INIS)

    Miura, Atsushi; Yamashita, Ichiro; Uraoka, Yukiharu; Fuyuki, Takashi; Tsukamoto, Rikako; Yoshii, Shigeo

    2008-01-01

    We demonstrated non-volatile flash memory fabrication by utilizing uniformly sized cobalt oxide (Co 3 O 4 ) bionanodot (Co-BND) architecture assembled by a cage-shaped supramolecular protein template. A fabricated high-density Co-BND array was buried in a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure to use as the charge storage node of a floating nanodot gate memory. We observed a clockwise hysteresis in the drain current-gate voltage characteristics of fabricated BND-embedded MOSFETs. Observed hysteresis obviously indicates a memory operation of Co-BND-embedded MOSFETs due to the charge confinement in the embedded BND and successful functioning of embedded BNDs as the charge storage nodes of the non-volatile flash memory. Fabricated Co-BND-embedded MOSFETs showed good memory properties such as wide memory windows, long charge retention and high tolerance to repeated write/erase operations. A new pathway for device fabrication by utilizing the versatile functionality of biomolecules is presented

  12. Nonvolatile rewritable memory device based on solution-processable graphene/poly(3-hexylthiophene) nanocomposite

    International Nuclear Information System (INIS)

    Zhang, Li; Li, Ye; Shi, Jun; Shi, Gaoquan; Cao, Shaokui

    2013-01-01

    An electrically bistable device utilizing a nanocomposite of hexadecylamine-functionalized graphene oxide (HDAGO) with poly(3-hexylthiophene) (P3HT) is demonstrated. The device has an ITO/P3HT-HDAGO/Al sandwich structure, in which the composite film of P3HT-HDAGO was prepared by simple solution phase mixing of the exfoliated HDAGO monolayers with P3HT matrix and a spin-coating method. The memory device exhibits typical bistable electrical switching behavior and a nonvolatile rewritable memory effect, with a turn-on voltage of about 1.5 V and an ON/OFF-state current ratio of 10 5 . Under ambient conditions, both the ON and OFF states are stable under a constant voltage stress or a continuous pulse voltage stress at a read voltage of 1 V. The conduction mechanism is deduced from the modeling of the nature of currents in both states, and the electrical switching behavior can be attributed to the electric-field-induced charge transfer between P3HT and HDAGO nanosheets. - Highlights: • Nonvolatile rewritable memory effect in P3HT–graphene composite is demonstrated. • The memory device was fabricated through a simple solution processing technique. • The device shows a remarkable electrical bistable behavior and excellent stability. • Memory mechanism is deduced from the modeling of the currents in both states

  13. Metal-organic molecular device for non-volatile memory storage

    International Nuclear Information System (INIS)

    Radha, B.; Sagade, Abhay A.; Kulkarni, G. U.

    2014-01-01

    Non-volatile memory devices have been of immense research interest for their use in active memory storage in powered off-state of electronic chips. In literature, various molecules and metal compounds have been investigated in this regard. Molecular memory devices are particularly attractive as they offer the ease of storing multiple memory states in a unique way and also represent ubiquitous choice for miniaturized devices. However, molecules are fragile and thus the device breakdown at nominal voltages during repeated cycles hinders their practical applicability. Here, in this report, a synergetic combination of an organic molecule and an inorganic metal, i.e., a metal-organic complex, namely, palladium hexadecylthiolate is investigated for memory device characteristics. Palladium hexadecylthiolate following partial thermolysis is converted to a molecular nanocomposite of Pd(II), Pd(0), and long chain hydrocarbons, which is shown to exhibit non-volatile memory characteristics with exceptional stability and retention. The devices are all solution-processed and the memory action stems from filament formation across the pre-formed cracks in the nanocomposite film.

  14. Two-dimensional non-volatile programmable p-n junctions

    Science.gov (United States)

    Li, Dong; Chen, Mingyuan; Sun, Zhengzong; Yu, Peng; Liu, Zheng; Ajayan, Pulickel M.; Zhang, Zengxing

    2017-09-01

    Semiconductor p-n junctions are the elementary building blocks of most electronic and optoelectronic devices. The need for their miniaturization has fuelled the rapid growth of interest in two-dimensional (2D) materials. However, the performance of a p-n junction considerably degrades as its thickness approaches a few nanometres and traditional technologies, such as doping and implantation, become invalid at the nanoscale. Here we report stable non-volatile programmable p-n junctions fabricated from the vertically stacked all-2D semiconductor/insulator/metal layers (WSe2/hexagonal boron nitride/graphene) in a semifloating gate field-effect transistor configuration. The junction exhibits a good rectifying behaviour with a rectification ratio of 104 and photovoltaic properties with a power conversion efficiency up to 4.1% under a 6.8 nW light. Based on the non-volatile programmable properties controlled by gate voltages, the 2D p-n junctions have been exploited for various electronic and optoelectronic applications, such as memories, photovoltaics, logic rectifiers and logic optoelectronic circuits.

  15. Flexible All-Inorganic Perovskite CsPbBr3 Nonvolatile Memory Device.

    Science.gov (United States)

    Liu, Dongjue; Lin, Qiqi; Zang, Zhigang; Wang, Ming; Wangyang, Peihua; Tang, Xiaosheng; Zhou, Miao; Hu, Wei

    2017-02-22

    All-inorganic perovskite CsPbX 3 (X = Cl, Br, or I) is widely used in a variety of photoelectric devices such as solar cells, light-emitting diodes, lasers, and photodetectors. However, studies to understand the flexible CsPbX 3 electrical application are relatively scarce, mainly due to the limitations of the low-temperature fabricating process. In this study, all-inorganic perovskite CsPbBr 3 films were successfully fabricated at 75 °C through a two-step method. The highly crystallized films were first employed as a resistive switching layer in the Al/CsPbBr 3 /PEDOT:PSS/ITO/PET structure for flexible nonvolatile memory application. The resistive switching operations and endurance performance demonstrated the as-prepared flexible resistive random access memory devices possess reproducible and reliable memory characteristics. Electrical reliability and mechanical stability of the nonvolatile device were further tested by the robust current-voltage curves under different bending angles and consecutive flexing cycles. Moreover, a model of the formation and rupture of filaments through the CsPbBr 3 layer was proposed to explain the resistive switching effect. It is believed that this study will offer a new setting to understand and design all-inorganic perovskite materials for future stable flexible electronic devices.

  16. Warm and hot electron distribution in the inner magnetosphere and the plasmasheet region related to the magnetospheric indices and the solar wind parameters: a statistical study form the NOAA POES TED and MEPED data

    Science.gov (United States)

    Boscher, Daniel; Rochel Grimald, Sandrine

    2013-04-01

    Using DMSP satellites, low altitude measurements has demonstrated to give a good picture of the plasmasheet population. The NOAA POES satellites are a constellation of five spacecraft orbiting in a polar orbit between 800 and 850 km and covering a wide L-shell range. They provide fourteen years of data without interruption which allow to make statistical study of the inner magnetosphere and the plasmasheet population. Moreover, since 2002, three of the NOAA POES satellites are located at different local times allowing to deduce the plasmasheet properties, even for huge magnetic activity. This paper present a statistical study of the warm and hot electron density over an energy range [0.16 ; 300] keV and between 1 and 12 Re. We present here maps in Mac Ilwain L paramater / MLT and we use the magnetic indices and solar wind parameter to classify our observations. The results show a clear motion of the plasmapause when Kp increase, which is in agreement with previous results, but it also show changes of the plasmapause shape and strong density variations in the night side sector. Moreover, a clear link between the solar wind parameters, in particular Bz, and the density distribution has been established. Unexpected distributions have been observed in the dayside and will be discussed here.

  17. Non-volatile MOS RAM cell with capacitor-isolated nodes that are radiation accessible for rendering a non-permanent programmed information in the cell of a non-volatile one

    NARCIS (Netherlands)

    Widdershoven, Franciscus P.; Annema, Anne J.; Storms, Maurits M.N.; Pelgrom, Marcellinus J.M.; Pelgrom, Marcel J M

    2001-01-01

    A non-volatile, random access memory cell comprises first and second inverters each having an output node cross-coupled by cross-coupling means to an input node of the other inverter for forming a MOS RAM cell. The output node of each inverter is selectively connected via the conductor paths of

  18. Multifunctional BiFeO{sub 3}/TiO{sub 2} nano-heterostructure: Photo-ferroelectricity, rectifying transport, and nonvolatile resistive switching property

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Ayan; Khan, Gobinda Gopal, E-mail: gobinda.gk@gmail.com [Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, Technology Campus, Block JD2, Sector III, Salt Lake City, Kolkata 700 098 (India); Chaudhuri, Arka [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake City, Kolkata 700 098 (India); Department of Applied Science, Haldia Institute of Technology, Haldia 721657, Purba Medinipur, West Bengal (India); Das, Avishek [Department of Electronic Science, University of Calcutta, 92 APC Road, Kolkata 700009 (India); Mandal, Kalyan [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake City, Kolkata 700 098 (India)

    2016-01-18

    Multifunctional BiFeO{sub 3} nanostructure anchored TiO{sub 2} nanotubes are fabricated by coupling wet chemical and electrochemical routes. BiFeO{sub 3}/TiO{sub 2} nano-heterostructure exhibits white-light-induced ferroelectricity at room temperature. Studies reveal that the photogenerated electrons trapped at the domain/grain boundaries tune the ferroelectric polarization in BiFeO{sub 3} nanostructures. The photon controlled saturation and remnant polarization opens up the possibility to design ferroelectric devices based on BiFeO{sub 3.} The nano-heterostructure also exhibits substantial photovoltaic effect and rectifying characteristics. Photovoltaic property is found to be correlated with the ferroelectric polarization. Furthermore, the nonvolatile resistive switching in BiFeO{sub 3}/TiO{sub 2} nano-heterostructure has been studied, which demonstrates that the observed resistive switching is most likely caused by the electric-field-induced carrier injection/migration and trapping/detrapping process at the hetero-interfaces. Therefore, BiFeO{sub 3}/TiO{sub 2} nano-heterostructure coupled with logic, photovoltaics and memory characteristics holds promises for long-term technological applications in nanoelectronics devices.

  19. Dietary exposure to volatile and non-volatile N-nitrosamines from processed meat products in Denmark

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange; Duedahl-Olesen, Lene; Christensen, Tue

    2015-01-01

    the carcinogenicity for the majority of the non-volatile NA (NVNA) remains to be elucidated. Danish adults (15–75 years) and children (4–6 years) consume 20 g and 16 g of processed meat per day (95th percentile), respectively. The consumption is primarily accounted for by sausages, salami, pork flank (spiced...

  20. Nonvolatile memory characteristics in metal-oxide-semiconductors containing metal nanoparticles fabricated by using a unique laser irradiation method

    International Nuclear Information System (INIS)

    Yang, JungYup; Yoon, KapSoo; Kim, JuHyung; Choi, WonJun; Do, YoungHo; Kim, ChaeOk; Hong, JinPyo

    2006-01-01

    Metal-oxide-semiconductor (MOS) capacitors with metal nanoparticles (Co NP) were successfully fabricated by utilizing an external laser exposure technique for application of non-volatile memories. Images of high-resolution transmission electron microscopy reveal that the spherically shaped Co NP are clearly embedded in the gate oxide layer. Capacitance-voltage measurements exhibit typical charging and discharging effects with a large flat-band shift. The effects of the tunnel oxide thickness and the different tunnel materials are analyzed using capacitance-voltage and retention characteristics. In addition, the memory characteristics of the NP embedded in a high-permittivity material are investigated because the thickness of conventionally available SiO 2 gates is approaching the quantum tunneling limit as devices are scaled down. Finally, the suitability of NP memory devices for nonvolatile memory applications is also discussed. The present results suggest that our unique laser exposure technique holds promise for the NP formation as floating gate elements in nonvolatile NP memories and that the quality of the tunnel oxide is very important for enhancing the retention properties of nonvolatile memory.

  1. Safe injection procedures, injection practices, and needlestick ...

    African Journals Online (AJOL)

    Nermine Mohamed Tawfik Foda

    2017-01-10

    Jan 10, 2017 ... sures regarding disposable injection equipment, waste containers, hand hygiene ... injection practices lead to high prevalence of NSSIs in operating rooms. .... guidelines, the availability of training courses to HCWs, and provi-.

  2. BLACKCOMB2: Hardware-software co-design for non-volatile memory in exascale systems

    Energy Technology Data Exchange (ETDEWEB)

    Mudge, Trevor [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-12-15

    This work was part of a larger project, Blackcomb2, centered at Oak Ridge National Labs (Jeff Vetter PI) to investigate the opportunities for replacing or supplementing DRAM main memory with nonvolatile memory (NVmemory) in Exascale memory systems. The goal was to reduce the energy consumed by in future supercomputer memory systems and to improve their resiliency. Building on the accomplishments of the original Blackcomb Project, funded in 2010, the goal for Blackcomb2 was to identify, evaluate, and optimize the most promising emerging memory technologies, architecture hardware and software technologies, which are essential to provide the necessary memory capacity, performance, resilience, and energy efficiency in Exascale systems. Capacity and energy are the key drivers.

  3. Controlled data storage for non-volatile memory cells embedded in nano magnetic logic

    Science.gov (United States)

    Riente, Fabrizio; Ziemys, Grazvydas; Mattersdorfer, Clemens; Boche, Silke; Turvani, Giovanna; Raberg, Wolfgang; Luber, Sebastian; Breitkreutz-v. Gamm, Stephan

    2017-05-01

    Among the beyond-CMOS technologies, perpendicular Nano Magnetic Logic (pNML) is a promising candidate due to its low power consumption, its non-volatility and its monolithic 3D integrability, which makes it possible to integrate memory and logic into the same device by exploiting the interaction of bi-stable nanomagnets with perpendicular magnetic anisotropy. Logic computation and signal synchronization are achieved by focus ion beam irradiation and by pinning domain walls in magnetic notches. However, in realistic circuits, the information storage and their read-out are crucial issues, often ignored in the exploration of beyond-CMOS devices. In this paper we address these issues by experimentally demonstrating a pNML memory element, whose read and write operations can be controlled by two independent pulsed currents. Our results prove the correct behavior of the proposed structure that enables high density memory embedded in the logic plane of 3D-integrated pNML circuits.

  4. Nonvolatile Memories Using Quantum Dot (QD) Floating Gates Assembled on II-VI Tunnel Insulators

    Science.gov (United States)

    Suarez, E.; Gogna, M.; Al-Amoody, F.; Karmakar, S.; Ayers, J.; Heller, E.; Jain, F.

    2010-07-01

    This paper presents preliminary data on quantum dot gate nonvolatile memories using nearly lattice-matched ZnS/Zn0.95Mg0.05S/ZnS tunnel insulators. The GeO x -cladded Ge and SiO x -cladded Si quantum dots (QDs) are self-assembled site-specifically on the II-VI insulator grown epitaxially over the Si channel (formed between the source and drain region). The pseudomorphic II-VI stack serves both as a tunnel insulator and a high- κ dielectric. The effect of Mg incorporation in ZnMgS is also investigated. For the control gate insulator, we have used Si3N4 and SiO2 layers grown by plasma- enhanced chemical vapor deposition.

  5. Physical implication of transition voltage in organic nano-floating-gate nonvolatile memories

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shun; Gao, Xu, E-mail: wangsd@suda.edu.cn, E-mail: gaoxu@suda.edu.cn; Zhong, Ya-Nan; Zhang, Zhong-Da; Xu, Jian-Long; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn, E-mail: gaoxu@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu 215123 (China)

    2016-07-11

    High-performance pentacene-based organic field-effect transistor nonvolatile memories, using polystyrene as a tunneling dielectric and Au nanoparticles as a nano-floating-gate, show parallelogram-like transfer characteristics with a featured transition point. The transition voltage at the transition point corresponds to a threshold electric field in the tunneling dielectric, over which stored electrons in the nano-floating-gate will start to leak out. The transition voltage can be modulated depending on the bias configuration and device structure. For p-type active layers, optimized transition voltage should be on the negative side of but close to the reading voltage, which can simultaneously achieve a high ON/OFF ratio and good memory retention.

  6. A Survey of Soft-Error Mitigation Techniques for Non-Volatile Memories

    Directory of Open Access Journals (Sweden)

    Sparsh Mittal

    2017-02-01

    Full Text Available Non-volatile memories (NVMs offer superior density and energy characteristics compared to the conventional memories; however, NVMs suffer from severe reliability issues that can easily eclipse their energy efficiency advantages. In this paper, we survey architectural techniques for improving the soft-error reliability of NVMs, specifically PCM (phase change memory and STT-RAM (spin transfer torque RAM. We focus on soft-errors, such as resistance drift and write disturbance, in PCM and read disturbance and write failures in STT-RAM. By classifying the research works based on key parameters, we highlight their similarities and distinctions. We hope that this survey will underline the crucial importance of addressing NVM reliability for ensuring their system integration and will be useful for researchers, computer architects and processor designers.

  7. Nonvolatile organic write-once-read-many-times memory devices based on hexadecafluoro-copper-phthalocyanine

    Science.gov (United States)

    Wang, Lidan; Su, Zisheng; Wang, Cheng

    2012-05-01

    Nonvolatile organic write-once-read-many-times memory device was demonstrated based on hexadecafluoro-copper-phthalocyanine (F16CuPc) single layer sandwiched between indium tin oxide (ITO) anode and Al cathode. The as fabricated device remains in ON state and it can be tuned to OFF state by applying a reverse bias. The ON/OFF current ratio of the device can reach up to 2.3 × 103. Simultaneously, the device shows long-term storage stability and long retention time in air. The ON/OFF transition is attributed to the formation and destruction of the interfacial dipole layer in the ITO/F16CuPc interface, and such a mechanism is different from previously reported ones.

  8. Discrete Charge Storage Nonvolatile Memory Based on Si Nanocrystals with Nitridation Treatment

    International Nuclear Information System (INIS)

    Xian-Gao, Zhang; Kun-Ji, Chen; Zhong-Hui, Fang; Xin-Ye, Qian; Guang-Yuan, Liu; Xiao-Fan, Jiang; Zhong-Yuan, Ma; Jun, Xu; Xin-Fan, Huang; Jian-Xin, Ji; Fei, He; Kuang-Bao, Song; Jun, Zhang; Hui, Wan; Rong-Hua, Wang

    2010-01-01

    A nonvolatile memory device with nitrided Si nanocrystals embedded in a Boating gate was fabricated. The uniform Si nanocrystals with high density (3 × 10 11 cm −2 ) were deposited on ultra-thin tunnel oxide layer (∼ 3 nm) and followed by a nitridation treatment in ammonia to form a thin silicon nitride layer on the surface of nanocrystals. A memory window of 2.4 V was obtained and it would be larger than 1.3 V after ten years from the extrapolated retention data. The results can be explained by the nitrogen passivation of the surface traps of Si nanocrystals, which slows the charge loss rate. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. The charge storage characteristics of ZrO2 nanocrystallite-based charge trap nonvolatile memory

    International Nuclear Information System (INIS)

    Tang Zhen-Jie; Li Rong; Yin Jiang

    2013-01-01

    ZrO 2 nanocrystallite-based charge trap flash memory capacitors incorporating a (ZrO 2 ) 0.6 (SiO 2 ) 0.4 pseudobinary high-k oxide film as the charge trapping layer were prepared and investigated. The precipitation reaction in the charge trapping layer, forming ZrO 2 nanocrystallites during rapid thermal annealing, was investigated by transmission electron microscopy and X-ray diffraction. It was observed that a ZrO 2 nanocrystallite-based memory capacitor after post-annealing at 850 °C for 60 s exhibits a maximum memory window of about 6.8 V, good endurance and a low charge loss of ∼25% over a period of 10 years (determined by extrapolating the charge loss curve measured experimentally), even at 85 °C. Such 850 °C-annealed memory capacitors appear to be candidates for future nonvolatile flash memory device applications

  10. Conjugated donor-acceptor-acceptor (D-A-A) molecule for organic nonvolatile resistor memory.

    Science.gov (United States)

    Dong, Lei; Li, Guangwu; Yu, An-Dih; Bo, Zhishan; Liu, Cheng-Liang; Chen, Wen-Chang

    2014-12-01

    A new donor-acceptor-acceptor (D-A-A) type of conjugated molecule, N-(4-(N',N'-diphenyl)phenylamine)-4-(4'-(2,2-dicyanovinyl)phenyl) naphthalene-1,8-dicarboxylic monoimide (TPA-NI-DCN), consisting of triphenylamine (TPA) donors and naphthalimide (NI)/dicyanovinylene (DCN) acceptors was synthesized and characterized. In conjunction with previously reported D-A based materials, the additional DCN moiety attached as end group in the D-A-A configuration can result in a stable charge transfer (CT) and charge-separated state to maintain the ON state current. The vacuum-deposited TPA-NI-DCN device fabricated as an active memory layer was demonstrated to exhibit write-once-read-many (WORM) switching characteristics of organic nonvolatile memory due to the strong polarity of the TPA-NI-DCN moiety. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Intrinsic Ge nanowire nonvolatile memory based on a simple core–shell structure

    International Nuclear Information System (INIS)

    Chen, Wen-Hua; Liu, Chang-Hai; Li, Qin-Liang; Sun, Qi-Jun; Liu, Jie; Gao, Xu; Sun, Xuhui; Wang, Sui-Dong

    2014-01-01

    Intrinsic Ge nanowires (NWs) with a Ge core covered by a thick Ge oxide shell are utilized to achieve nanoscale field-effect transistor nonvolatile memories, which show a large memory window and a high ON/OFF ratio with good retention. The retainable surface charge trapping is considered to be responsible for the memory effect, and the Ge oxide shell plays a key role as the insulating tunneling dielectric which must be thick enough to prevent stored surface charges from leaking out. Annealing the device in air is demonstrated to be a simple and effective way to attain thick Ge oxide on the Ge NW surface, and the Ge-NW-based memory corresponding to thick Ge oxide exhibits a much better retention capability compared with the case of thin Ge oxide. (paper)

  12. Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the determination of nonvolatile residue (NVR) fallout in environmentally controlled areas used for the assembly, testing, and processing of spacecraft. 1.2 The NVR of interest is that which is deposited on sampling plate surfaces at room temperature: it is left to the user to infer the relationship between the NVR found on the sampling plate surface and that found on any other surfaces. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  13. Standard Test Method for Gravimetric Determination of Nonvolatile Residue From Cleanroom Wipers

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method covers the determination of solvent extractable nonvolatile residue (NVR) from wipers used in assembly, cleaning, or testing of spacecraft, but not from those used for analytical surface sampling of hardware. 1.2 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.3 The NVR of interest is that which can be extracted from cleanroom wipers using a specified solvent that has been selected for its extractive qualities. Alternative solvents may be selected, but since their use may result in different values being generated, they must be identified in the procedure data sheet. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. The floating-gate non-volatile semiconductor memory--from invention to the digital age.

    Science.gov (United States)

    Sze, S M

    2012-10-01

    In the past 45 years (from 1967 to 2012), the non-volatile semiconductor memory (NVSM) has emerged from a floating-gate concept to the prime technology driver of the largest industry in the world-the electronics industry. In this paper, we briefly review the historical development of NVSM and project its future trends to the year 2020. In addition, we consider NVSM's wide-range of applications from the digital cellular phone to tablet computer to digital television. As the device dimension is scaled down to the deca-nanometer regime, we expect that many innovations will be made to meet the scaling challenges, and NVSM-inspired technology will continue to enrich and improve our lives for decades to come.

  15. Low-field Switching Four-state Nonvolatile Memory Based on Multiferroic Tunnel Junctions

    Science.gov (United States)

    Yau, H. M.; Yan, Z. B.; Chan, N. Y.; Au, K.; Wong, C. M.; Leung, C. W.; Zhang, F. Y.; Gao, X. S.; Dai, J. Y.

    2015-08-01

    Multiferroic tunneling junction based four-state non-volatile memories are very promising for future memory industry since this kind of memories hold the advantages of not only the higher density by scaling down memory cell but also the function of magnetically written and electrically reading. In this work, we demonstrate a success of this four-state memory in a material system of NiFe/BaTiO3/La0.7Sr0.3MnO3 with improved memory characteristics such as lower switching field and larger tunneling magnetoresistance (TMR). Ferroelectric switching induced resistive change memory with OFF/ON ratio of 16 and 0.3% TMR effect have been achieved in this multiferroic tunneling structure.

  16. Poly (vinylidene fluoride-trifluoroethylene/barium titanate nanocomposite for ferroelectric nonvolatile memory devices

    Directory of Open Access Journals (Sweden)

    Uvais Valiyaneerilakkal

    2013-04-01

    Full Text Available The effect of barium titanate (BaTiO3 nanoparticles (particle size <100nm on the ferroelectric properties of poly (vinylidenefluoride-trifluoroethylene P(VDF-TrFE copolymer has been studied. Different concentrations of nanoparticles were added to P(VDF-TrFE using probe sonication, and uniform thin films were made. Polarisation - Electric field (P-E hysteresis analysis shows an increase in remnant polarization (Pr and decrease in coercive voltage (Vc. Piezo-response force microscopy analysis shows the switching capability of the polymer composite. The topography and surface roughness was studied using atomic force microscopy. It has been observed that this nanocomposite can be used for the fabrication of non-volatile ferroelectric memory devices.

  17. Measurements of the size dependence of the concentration of nonvolatile material in fog droplets

    Science.gov (United States)

    Ogren, J. A.; Noone, K. J.; Hallberg, A.; Heintzenberg, J.; Schell, D.; Berner, A.; Solly, I.; Kruisz, C.; Reischl, G.; Arends, B. G.; Wobrock, W.

    1992-11-01

    Measurements of the size dependence of the mass concentration of nonvolatile material dissolved and suspended in fog droplets were obtained with three complementary approaches, covering a size range from c. 1 50µm diameter: a counterflow virtual impactor, an eight-stage aerosol impactor, and a two-stage fogwater impactor. Concentrations were observed to decrease with size over the entire range, contrary to expectations of increasing concentrations at larger sizes. It is possible that the larger droplets had solute concentrations that increased with increasing size, but that the increase was too weak for the measurements to resolve. Future studies should consider the hypothesis that the droplets were coated with a surface-active substance that hindered their uptake of water.

  18. Nonvolatile Solid-State Charged-Polymer Gating of Topological Insulators into the Topological Insulating Regime

    Science.gov (United States)

    Ireland, R. M.; Wu, Liang; Salehi, M.; Oh, S.; Armitage, N. P.; Katz, H. E.

    2018-04-01

    We demonstrate the ability to reduce the carrier concentration of thin films of the topological insulator (TI) Bi2 Se3 by utilizing a nonvolatile electrostatic gating via corona charging of electret polymers. Sufficient electric field can be imparted to a polymer-TI bilayer to result in significant electron density depletion, even without the continuous connection of a gate electrode or the chemical modification of the TI. We show that the Fermi level of Bi2 Se3 is shifted toward the Dirac point with this method. Using terahertz spectroscopy, we find that the surface chemical potential is lowered into the bulk band gap (approximately 50 meV above the Dirac point and 170 meV below the conduction-band minimum), and it is stabilized in the intrinsic regime while enhancing electron mobility. The mobility of surface state electrons is enhanced to a value as high as approximately 1600 cm2/V s at 5 K.

  19. A direct metal transfer method for cross-bar type polymer non-volatile memory applications

    International Nuclear Information System (INIS)

    Kim, Tae-Wook; Lee, Kyeongmi; Oh, Seung-Hwan; Wang, Gunuk; Kim, Dong-Yu; Jung, Gun-Young; Lee, Takhee

    2008-01-01

    Polymer non-volatile memory devices in 8 x 8 array cross-bar architecture were fabricated by a non-aqueous direct metal transfer (DMT) method using a two-step thermal treatment. Top electrodes with a linewidth of 2 μm were transferred onto the polymer layer by the DMT method. The switching behaviour of memory devices fabricated by the DMT method was very similar to that of devices fabricated by the conventional shadow mask method. The devices fabricated using the DMT method showed three orders of magnitude of on/off ratio with stable resistance switching, demonstrating that the DMT method can be a simple process to fabricate organic memory array devices

  20. A room-temperature non-volatile CNT-based molecular memory cell

    Science.gov (United States)

    Ye, Senbin; Jing, Qingshen; Han, Ray P. S.

    2013-04-01

    Recent experiments with a carbon nanotube (CNT) system confirmed that the innertube can oscillate back-and-forth even under a room-temperature excitation. This demonstration of relative motion suggests that it is now feasible to build a CNT-based molecular memory cell (MC), and the key to bring the concept to reality is the precision control of the moving tube for sustained and reliable read/write (RW) operations. Here, we show that by using a 2-section outertube design, we are able to suitably recalibrate the system energetics and obtain the designed performance characteristics of a MC. Further, the resulting energy modification enables the MC to operate as a non-volatile memory element at room temperatures. Our paper explores a fundamental understanding of a MC and its response at the molecular level to roadmap a novel approach in memory technologies that can be harnessed to overcome the miniaturization limit and memory volatility in memory technologies.

  1. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids

    Directory of Open Access Journals (Sweden)

    Hongbin Lin

    2018-05-01

    Full Text Available Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC. Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln, glutamic acid (Glu, aspartic acid (Asp and asparagines (Asn were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  2. Method for the Collection, Gravimetric and Chemical Analysis of Nonvolatile Residue (NVR) on Surfaces

    Science.gov (United States)

    Gordon, Keith; Rutherford, Gugu; Aranda, Denisse

    2017-01-01

    Nonvolatile residue (NVR), sometimes referred to as molecular contamination is the term used for the total composition of the inorganic and high boiling point organic components in particulates and molecular films deposited on critical surfaces surrounding space structures, with the particulate and NVR contamination originating primarily from pre-launch operations. The "nonvolatile" suggestion from the terminology NVR implies that the collected residue will not experience much loss under ambient conditions. NVR has been shown to have a dramatic impact on the ability to perform optical measurements from platforms based in space. Such contaminants can be detected early by the controlled application of various detection techniques and contamination analyses. Contamination analyses are the techniques used to determine if materials, components, and subsystems can be expected to meet the performance requirements of a system. Of particular concern is the quantity of NVR contaminants that might be deposited on critical payload surfaces from these sources. Subsequent chemical analysis of the contaminant samples by infrared spectroscopy and gas chromatography mass spectrometry identifies the components, gives semi-quantitative estimates of contaminant thickness, indicates possible sources of the NVR, and provides guidance for effective cleanup procedures. In this report, a method for the collection and determination of the mass of NVR was generated by the authors at NASA Langley Research Center. This report describes the method developed and implemented for collecting NVR contaminants, and procedures for gravimetric and chemical analysis of the residue obtained. The result of this NVR analysis collaboration will help pave the way for Langley's ability to certify flight hardware outgassing requirements in support of flight projects such as Stratospheric Aerosol and Gas Experiment III (SAGE III), Clouds and the Earth's Radiant Energy System (CERES), Materials International

  3. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids.

    Science.gov (United States)

    Lin, Hongbin; Yu, Xiaoyu; Fang, Jiaxing; Lu, Yunhao; Liu, Ping; Xing, Yage; Wang, Qin; Che, Zhenming; He, Qiang

    2018-05-29

    Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC). Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln), glutamic acid (Glu), aspartic acid (Asp) and asparagines (Asn) were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  4. Development of novel nonvolatile memory devices using the colossal magnetoresistive oxide praseodymium-calcium-manganese trioxide

    Science.gov (United States)

    Papagianni, Christina

    Pr0.7Ca0.3MnO3 (PCMO) manganese oxide belongs in the family of materials known as transition metal oxides. These compounds have received increased attention due to their perplexing properties such as Colossal Magnetoresistance effect, Charge-Ordered phase, existence of phase-separated states etc. In addition, it was recently discovered that short electrical pulses in amplitude and duration are sufficient to induce reversible and non-volatile resistance changes in manganese perovskite oxide thin films at room temperature, known as the EPIR effect. The existence of the EPIR effect in PCMO thin films at room temperature opens a viable way for the realization of fast, high-density, low power non-volatile memory devices in the near future. The purpose of this study is to investigate, optimize and understand the properties of Pr0.7Ca0.3MnO 3 (PCMO) thin film devices and to identify how these properties affect the EPIR effect. PCMO thin films were deposited on various substrates, such as metals, and conducting and insulating oxides, by pulsed laser and radio frequency sputtering methods. Our objective was to understand and compare the induced resistive states. We attempted to identify the induced resistance changes by considering two resistive models to be equivalent to our devices. Impedance spectroscopy was also utilized in a wide temperature range that was extended down to 70K. Fitted results of the temperature dependence of the resistance states were also included in this study. In the same temperature range, we probed the resistance changes in PCMO thin films and we examined whether the phase transitions affect the EPIR effect. In addition, we included a comparison of devices with electrodes consisting of different size and different materials. We demonstrated a direct relation between the EPIR effect and the phase diagram of bulk PCMO samples. A model that could account for the observed EPIR effect is presented.

  5. Microwave interaction with hot electron plasmas

    International Nuclear Information System (INIS)

    Tanaka, M.; Fujiwara, M.; Ikegami, H.

    1980-01-01

    A numerical calculation is presented of ray trajectories and cyclotron damping for toroidal plasmas using geometrical optics. In the absorption region, group velocity does not always coincide with the velocity of energy flow, therefore it should be careful to apply the geometrical optics to finite temperature plasmas. In these calculations, attention is paid mainly to the finite temperature effect on ray tracing. Some numerical results for ordinary waves are presented. Second, new cutoff and resonance appear in the plasmas with anisotropic electron temperature. This resonance frequency is shifted from the usual cyclotron resonance by an amount proportional to T 11 /mc 2 , so that one can determine T 11 when this resonance frequency is measured. A simple discussion is given. The results are presented of recent density measurement on Nagoya Bumpy Torus obtained by interferometer system with different frequencies, 35 GHz and 55 GHz. The results are different than each other in T-mode. The possible reasons for these differences are enumerated in this section

  6. Injection Laryngoplasty Materials

    OpenAIRE

    Haldun Oðuz

    2013-01-01

    Injection laryngoplasty is one of the treatment options for voice problems. In the recent years, more safe and more biocompatible injection materials are available on the market. Long and short term injection materials are discussed in this review.

  7. Penicillin G Procaine Injection

    Science.gov (United States)

    Penicillin G procaine injection is used to treat certain infections caused by bacteria. Penicillin G procaine injection should not be used to ... early in the treatment of certain serious infections. Penicillin G procaine injection is in a class of ...

  8. Externally Controlled Injection of Electrons by a Laser Pulse in a Laser Wakefield Electron Accelerator

    CERN Document Server

    Chen Szu Yuan; Chen Wei Ting; Chien, Ting-Yei; Lee, Chau-Hwang; Lin, Jiunn-Yuan; Wang, Jyhpyng

    2005-01-01

    Spatially and temporally localized injection of electrons is a key element for development of plasma-wave electron accelerator. Here we report the demonstration of two different schemes for electron injection in a self-modulated laser wakefield accelerator (SM-LWFA) by using a laser pulse. In the first scheme, by implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. We found that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the pump pulse. In the second scheme, by using a transient density ramp we achieve self-injection of electrons in a SM-LWFA with spatial localization. The transient density ramp is produced by a prepulse propagating transversely to drill a density depression channel via ionization and expansion. The same mechanism of injection with comparable efficiency is also demonstrated wi...

  9. Laboratory Validation of Four Black Carbon Measurement Methods for Determination of the Nonvolatile Particulate Matter (nvPM) Mass Emissions from Commercial Aircraft Engines

    Science.gov (United States)

    Four candidate black carbon (BC) measurement techniques have been identified by the SAE International E-31 Committee for possible use in determining nonvolatile particulate matter (nvPM) mass emissions during commercial aircraft engine certification. These techniques are carbon b...

  10. EPA Method 8321B (SW-846): Solvent-Extractable Nonvolatile Compounds by High Performance Liquid Chromatography-Thermospray-Mass Spectrometry (HPLC-TS-MS) or Ultraviolet (UV) Detection

    Science.gov (United States)

    Method 8321B describes procedures for preparation and analysis of solid, aqueous liquid, drinking water and wipe samples using high performance liquid chromatography and mass spectrometry for extractable non-volatile compounds.

  11. Atomically Smooth Epitaxial Ferroelectric Thin Films for the Development of a Nonvolatile, Ultrahigh Density, Fast, Low Voltage, Radiation-Hard Memory

    National Research Council Canada - National Science Library

    Ahn, Charles H

    2006-01-01

    The goal of this research is to fabricate atomically smooth, single crystalline, complex oxide thin film nanostructures for use in a nonvolatile, ultrahigh density, fast, low voltage, radiation-hard memory...

  12. Feasibility and limitations of anti-fuses based on bistable non-volatile switches for power electronic applications

    Science.gov (United States)

    Erlbacher, T.; Huerner, A.; Bauer, A. J.; Frey, L.

    2012-09-01

    Anti-fuse devices based on non-volatile memory cells and suitable for power electronic applications are demonstrated for the first time using silicon technology. These devices may be applied as stand alone devices or integrated using standard junction-isolation into application-specific and smart-power integrated circuits. The on-resistance of such devices can be permanently switched by nine orders of magnitude by triggering the anti-fuse with a positive voltage pulse. Extrapolation of measurement data and 2D TCAD process and device simulations indicate that 20 A anti-fuses with 10 mΩ can be reliably fabricated in 0.35 μm technology with a footprint of 2.5 mm2. Moreover, this concept offers distinguished added-values compared to existing mechanical relays, e.g. pre-test, temporary and permanent reset functions, gradual turn-on mode, non-volatility, and extendibility to high voltage capability.

  13. Broadband nonvolatile photonic switching based on optical phase change materials: beyond the classical figure-of-merit.

    Science.gov (United States)

    Zhang, Qihang; Zhang, Yifei; Li, Junying; Soref, Richard; Gu, Tian; Hu, Juejun

    2018-01-01

    In this Letter, we propose a broadband, nonvolatile on-chip switch design in the telecommunication C-band with record low loss and crosstalk. The unprecedented device performance builds on: 1) a new optical phase change material (O-PCM) Ge 2 Sb 2 Se 4 Te 1 (GSST), which exhibits significantly reduced optical attenuation compared to traditional O-PCMs, and 2) a nonperturbative design that enables low-loss device operation beyond the classical figure-of-merit (FOM) limit. We further demonstrate that the 1-by-2 and 2-by-2 switches can serve as basic building blocks to construct nonblocking and nonvolatile on-chip switching fabric supporting arbitrary numbers of input and output ports.

  14. Influence of mineral salts upon activity of Trichoderma harzianum non-volatile metabolites on Armillaria spp. rhizomorphs

    Directory of Open Access Journals (Sweden)

    Krystyna Przybył

    2011-01-01

    Full Text Available Effect of non-volatile metabolites of Trichoderma harzianum together with certain salts containing Mg++, Fe+++, Mn++, Cu++, Al+++, Ca++, K++, Na+, PO4--- and SO3--- on the production and length of rhizomorphs of Armillaria borealis, A. gallica and A. ostoyae was studied. In pure medium, T. harzianum exhibited stimulating effect on rhizomorphs of A. borealis (both number and length and A. ostoyae (only initiation. Cu++ salt totaly inhibited the initiation of rhizomorphs of Armillaria borealis, A. gallica and A. ostoyae. Effect of other compounds on the activity of T. harzianum depended on Armillaria species. The majority of chemical compounds tested supressed the activity of non-volatile metabolites of T. harzianum. Evident stimulating effect was observed under influence of sulphate salts consisting Al++ and Fe+++ on the rhizomorph number of A. borealis and A. gallica, respectively.

  15. Unipolar resistive switching in metal oxide/organic semiconductor non-volatile memories as a critical phenomenon

    International Nuclear Information System (INIS)

    Bory, Benjamin F.; Meskers, Stefan C. J.; Rocha, Paulo R. F.; Gomes, Henrique L.; Leeuw, Dago M. de

    2015-01-01

    Diodes incorporating a bilayer of an organic semiconductor and a wide bandgap metal oxide can show unipolar, non-volatile memory behavior after electroforming. The prolonged bias voltage stress induces defects in the metal oxide with an areal density exceeding 10 17  m −2 . We explain the electrical bistability by the coexistence of two thermodynamically stable phases at the interface between an organic semiconductor and metal oxide. One phase contains mainly ionized defects and has a low work function, while the other phase has mainly neutral defects and a high work function. In the diodes, domains of the phase with a low work function constitute current filaments. The phase composition and critical temperature are derived from a 2D Ising model as a function of chemical potential. The model predicts filamentary conduction exhibiting a negative differential resistance and nonvolatile memory behavior. The model is expected to be generally applicable to any bilayer system that shows unipolar resistive switching

  16. Ferroelectric polymer gates for non-volatile field effect control of ferromagnetism in (Ga, Mn)As layers

    International Nuclear Information System (INIS)

    Stolichnov, I; Riester, S W E; Mikheev, E; Setter, N; Rushforth, A W; Edmonds, K W; Campion, R P; Foxon, C T; Gallagher, B L; Jungwirth, T; Trodahl, H J

    2011-01-01

    (Ga, Mn)As and other diluted magnetic semiconductors (DMS) attract a great deal of attention for potential spintronic applications because of the possibility of controlling the magnetic properties via electrical gating. Integration of a ferroelectric gate on the DMS channel adds to the system a non-volatile memory functionality and permits nanopatterning via the polarization domain engineering. This topical review is focused on the multiferroic system, where the ferromagnetism in the (Ga, Mn)As DMS channel is controlled by the non-volatile field effect of the spontaneous polarization. Use of ferroelectric polymer gates in such heterostructures offers a viable alternative to the traditional oxide ferroelectrics generally incompatible with DMS. Here we review the proof-of-concept experiments demonstrating the ferroelectric control of ferromagnetism, analyze the performance issues of the ferroelectric gates and discuss prospects for further development of the ferroelectric/DMS heterostructures toward the multiferroic field effect transistor. (topical review)

  17. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

    Science.gov (United States)

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

    2016-10-01

    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  18. Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

    Science.gov (United States)

    Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

    2016-02-01

    We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

  19. Non-volatile resistive switching in the Mott insulator (V1-xCrx)2O3

    Science.gov (United States)

    Querré, M.; Tranchant, J.; Corraze, B.; Cordier, S.; Bouquet, V.; Députier, S.; Guilloux-Viry, M.; Besland, M.-P.; Janod, E.; Cario, L.

    2018-05-01

    The discovery of non-volatile resistive switching in Mott insulators related to an electric-field-induced insulator to metal transition (IMT) has paved the way for their use in a new type of non-volatile memories, the Mott memories. While most of the previous studies were dedicated to uncover the resistive switching mechanism and explore the memory potential of chalcogenide Mott insulators, we present here a comprehensive study of resistive switching in the canonical oxide Mott insulator (V1-xCrx)2O3. Our work demonstrates that this compound undergoes a non-volatile resistive switching under electric field. This resistive switching is induced by a Mott transition at the local scale which creates metallic domains closely related to existing phases of the temperature-pressure phase diagram of (V1-xCrx)2O3. Our work demonstrates also reversible resistive switching in (V1-xCrx)2O3 crystals and thin film devices. Preliminary performances obtained on 880 nm thick layers with 500 nm electrodes show the strong potential of Mott memories based on the Mott insulator (V1-xCrx)2O3.

  20. Safe injection procedures, injection practices, and needlestick ...

    African Journals Online (AJOL)

    Nermine Mohamed Tawfik Foda

    2017-01-10

    Jan 10, 2017 ... Background: Of the estimated 384,000 needle-stick injuries occurring in hospitals each year, 23% occur in surgical settings. This study was conducted to assess safe injection procedures, injection practices, and circumstances contributing to needlestick and sharps injures (NSSIs) in operating rooms.

  1. Anomalous Threshold Voltage Variability of Nitride Based Charge Storage Nonvolatile Memory Devices

    Directory of Open Access Journals (Sweden)

    Meng Chuan Lee

    2013-01-01

    Full Text Available Conventional technology scaling is implemented to meet the insatiable demand of high memory density and low cost per bit of charge storage nonvolatile memory (NVM devices. In this study, effect of technology scaling to anomalous threshold voltage ( variability is investigated thoroughly on postcycled and baked nitride based charge storage NVM devices. After long annealing bake of high temperature, cell’s variability of each subsequent bake increases within stable distribution and found exacerbate by technology scaling. Apparent activation energy of this anomalous variability was derived through Arrhenius plots. Apparent activation energy (Eaa of this anomalous variability is 0.67 eV at sub-40 nm devices which is a reduction of approximately 2 times from 110 nm devices. Technology scaling clearly aggravates this anomalous variability, and this poses reliability challenges to applications that demand strict control, for example, reference cells that govern fundamental program, erase, and verify operations of NVM devices. Based on critical evidence, this anomalous variability is attributed to lateral displacement of trapped charges in nitride storage layer. Reliability implications of this study are elucidated. Moreover, potential mitigation methods are proposed to complement technology scaling to prolong the front-runner role of nitride based charge storage NVM in semiconductor flash memory market.

  2. Nonvolatile field effect transistors based on protons and Si/SiO2Si structures

    International Nuclear Information System (INIS)

    Warren, W.L.; Vanheusden, K.; Fleetwood, D.M.; Schwank, J.R.; Winokur, P.S.; Knoll, M.G.; Devine, R.A.B.

    1997-01-01

    Recently, the authors have demonstrated that annealing Si/SiO 2 /Si structures in a hydrogen containing ambient introduces mobile H + ions into the buried SiO 2 layer. Changes in the H + spatial distribution within the SiO 2 layer were electrically monitored by current-voltage (I-V) measurements. The ability to directly probe reversible protonic motion in Si/SiO 2 /Si structures makes this an exemplar system to explore the physics and chemistry of hydrogen in the technologically relevant Si/SiO 2 structure. In this work, they illustrate that this effect can be used as the basis for a programmable nonvolatile field effect transistor (NVFET) memory that may compete with other Si-based memory devices. The power of this novel device is its simplicity; it is based upon standard Si/SiO 2 /Si technology and forming gas annealing, a common treatment used in integrated circuit processing. They also briefly discuss the effects of radiation on its retention properties

  3. The MONOS memory transistor: application in a radiation-hard nonvolatile RAM

    International Nuclear Information System (INIS)

    Brown, W.D.

    1985-01-01

    The MONOS (metal-oxide-nitride-oxide-silicon) device is a prime candidate for use as the nonvolatile memory element in a radiation-hardened RAM (random-access memory). The endurance, retention and radiation properties of MONOS memory transistors have been studied as a function of post nitride deposition annealing. Following the nitride layer deposition, all devices were subjected to an 800 0 C oxidation step and some were then annealed at 900 0 C in nitrogen. The nitrogen anneal produces an increase in memory window size of approximately 40%. The memory window center of the annealed devices is shifted toward more positive voltages and is more stable with endurance cycling. Endurance cycling to 10 9 cycles produces a 20% increase in memory window size and a 60% increase in decay rate. For a radiation total dose of 10 6 rads (Si), the memory window size is essentially unchanged and the decay rate increases approximately 13%. A combination of 10 9 cycles and 10 6 rads (Si) reduces the decades of retention (in sec) from 6.3 to 4.3 for a +- 23-V 16-μsec write/erase pulse. (author)

  4. Comparison of non-volatile umami components in chicken soup and chicken enzymatic hydrolysate.

    Science.gov (United States)

    Kong, Yan; Yang, Xiao; Ding, Qi; Zhang, Yu-Yu; Sun, Bao-Guo; Chen, Hai-Tao; Sun, Ying

    2017-12-01

    Umami taste is an important part to the taste of chicken. To isolate and identify non-volatile umami compounds, fractions from chicken soup and hydrolysate were prepared and analyzed. Amino acids were analyzed by amino acid analyzer. Organic acids and nucleotides were determined by ultra-performance liquid chromatography. Separation procedures utilizing ultrafiltration, Sephadex G-15 and reversed-phase high-performance liquid chromatography were used to isolate umami taste peptides. Combined with sensory evaluation and LC-Q-TOF-MS, the amino acid sequences of 12 oligopeptides were determined. The amount of taste compounds was higher in chicken enzymatic hydrolysate than that of chicken soup. Eight oligopeptides from chicken enzymatic hydrolysate were identified, including Ala-Asp, Ala-Met, His-Ser, Val-Glu, Ala-Glu, Asp-Ala-Gly, Glu-Asp and Ala-Glu-Ala. Four oligopeptides from chicken soup were identified, including Val-Thr, Ala-His, Ala-Phe and Thr-Glu. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Discharge characteristics of an ablative pulsed plasma thruster with non-volatile liquid propellant

    Science.gov (United States)

    Ling, William Yeong Liang; Schönherr, Tony; Koizumi, Hiroyuki

    2017-07-01

    Pulsed plasma thrusters (PPTs) are a form of electric spacecraft propulsion. They have an extremely simple structure and are highly suitable for nano/micro-spacecraft with weights in the kilogram range. Such small spacecraft have recently experienced increased growth but still lack suitable efficient propulsion systems. PPTs operate in a pulsed mode (one discharge = one shot) and typically use solid polytetrafluoroethylene (PTFE) as a propellant. However, new non-volatile liquids in the perfluoropolyether (PFPE) family have recently been found to be promising alternatives. A recent study presented results on the physical characteristics of PFPE vs. PTFE, showing that PFPE is superior in terms of physical characteristics such as its resistance to carbon deposition. This letter will examine the electrical discharge characteristics of PFPE vs. PTFE. The results demonstrate that PFPE has excellent shot-to-shot repeatability and a lower discharge resistance when compared with PTFE. Taken together with its physical characteristics, PFPE appears to be a strong contender to PTFE as a PPT propellant.

  6. Controlled data storage for non-volatile memory cells embedded in nano magnetic logic

    Directory of Open Access Journals (Sweden)

    Fabrizio Riente

    2017-05-01

    Full Text Available Among the beyond-CMOS technologies, perpendicular Nano Magnetic Logic (pNML is a promising candidate due to its low power consumption, its non-volatility and its monolithic 3D integrability, which makes it possible to integrate memory and logic into the same device by exploiting the interaction of bi-stable nanomagnets with perpendicular magnetic anisotropy. Logic computation and signal synchronization are achieved by focus ion beam irradiation and by pinning domain walls in magnetic notches. However, in realistic circuits, the information storage and their read-out are crucial issues, often ignored in the exploration of beyond-CMOS devices. In this paper we address these issues by experimentally demonstrating a pNML memory element, whose read and write operations can be controlled by two independent pulsed currents. Our results prove the correct behavior of the proposed structure that enables high density memory embedded in the logic plane of 3D-integrated pNML circuits.

  7. Origami-based tunable truss structures for non-volatile mechanical memory operation.

    Science.gov (United States)

    Yasuda, Hiromi; Tachi, Tomohiro; Lee, Mia; Yang, Jinkyu

    2017-10-17

    Origami has recently received significant interest from the scientific community as a method for designing building blocks to construct metamaterials. However, the primary focus has been placed on their kinematic applications by leveraging the compactness and auxeticity of planar origami platforms. Here, we present volumetric origami cells-specifically triangulated cylindrical origami (TCO)-with tunable stability and stiffness, and demonstrate their feasibility as non-volatile mechanical memory storage devices. We show that a pair of TCO cells can develop a double-well potential to store bit information. What makes this origami-based approach more appealing is the realization of two-bit mechanical memory, in which two pairs of TCO cells are interconnected and one pair acts as a control for the other pair. By assembling TCO-based truss structures, we experimentally verify the tunable nature of the TCO units and demonstrate the operation of purely mechanical one- and two-bit memory storage prototypes.Origami is a popular method to design building blocks for mechanical metamaterials. Here, the authors assemble a volumetric origami-based structure, predict its axial and rotational movements during folding, and demonstrate the operation of mechanical one- and two-bit memory storage.

  8. Investigations concerning the exchange of iodine from non-volatile organic iodine compounds

    International Nuclear Information System (INIS)

    Psarros, N.; Duschner, H.; Molzahn, D.; Schmidt, L.; Heise, S.; Jungclas, H.; Brandt, R.; Patzelt, P.

    1990-10-01

    The iodine produced by nuclear fission is removed during the reprocessing of exhausted nuclear fuel elements by desorption achieving good decontamination factors. Nevertheless the further optimization of the process requires detailed information about the iodine speciation during fuel reprocessing, and about possible reactions. For the study of decomposition reactions of iodo-alcanes, which are built up during the fuel recycling process, we developed a method for the synthesis of labelled iodo-dodecane, which was used as tracer. In order to identify the iodo species in the organic phase of the reprocessing cycle we applied plasma desorption time-of-flight mass spectroscopy. The problem of the volatility of the iodo-compounds in the ultra vacuum of the mass spectrometer was overcome by derivatization of the iodo-alcanes with dithizon, which yielded non-volatile ionic alcyltetrazolium iodides. Beta-spectrometric analysis of the exhaust condensates collected from the organic phase of the WAK reprocessing cycle revealed beside iodine-129 the existence of a low-energetic beta emitter, which has yet to be identified. A literature survey on the topic was also performed. (orig.) With 42 refs., 9 figs [de

  9. Non-volatile main memory management methods based on a file system.

    Science.gov (United States)

    Oikawa, Shuichi

    2014-01-01

    There are upcoming non-volatile (NV) memory technologies that provide byte addressability and high performance. PCM, MRAM, and STT-RAM are such examples. Such NV memory can be used as storage because of its data persistency without power supply while it can be used as main memory because of its high performance that matches up with DRAM. There are a number of researches that investigated its uses for main memory and storage. They were, however, conducted independently. This paper presents the methods that enables the integration of the main memory and file system management for NV memory. Such integration makes NV memory simultaneously utilized as both main memory and storage. The presented methods use a file system as their basis for the NV memory management. We implemented the proposed methods in the Linux kernel, and performed the evaluation on the QEMU system emulator. The evaluation results show that 1) the proposed methods can perform comparably to the existing DRAM memory allocator and significantly better than the page swapping, 2) their performance is affected by the internal data structures of a file system, and 3) the data structures appropriate for traditional hard disk drives do not always work effectively for byte addressable NV memory. We also performed the evaluation of the effects caused by the longer access latency of NV memory by cycle-accurate full-system simulation. The results show that the effect on page allocation cost is limited if the increase of latency is moderate.

  10. Determination of Nonvolatile Amines in Foods by Improved Dansyl Derivatization Reaction.

    Science.gov (United States)

    Handa, Ayami; Kawanabe, Hitomi; Ibe, Akihiro

    2017-01-01

    An analytical method for the determination of nonvolatile amines (putrescine, cadaverine, histamine, tyramine, and spermidine) in foods was developed, using an improved dansyl derivatization technique. The five amines were extracted from food with 1% trichloroacetic acid. Three milliliter of extract was applied to a polymer-based strong cation exchange resin mini-column, which was washed with 5 mL of water, and eluted with 5 mL of 1 mol/L potassium carbonate solution. The eluate was dansylated, then 5 mL of toluene was added with shaking. The toluene layer was evaporated. The residue was taken up in 1 mL of acetonitrile and shaken with 1 mL of 5% proline in 1 mol/L potassium carbonate solution. The upper acetonitrile layer was collected, filtered, and subjected to HPLC. The limits of quantitation for putrescine and cadaverine in the samples were both 0.2 μg/g; those of spermidine, tyramine, and histamine were 0.8, 2.0, and 5.0 μg/g, respectively. The average recoveries of the five amines from nine foods exceeded 80%.

  11. An Investigation of Quantum Dot Super Lattice Use in Nonvolatile Memory and Transistors

    Science.gov (United States)

    Mirdha, P.; Parthasarathy, B.; Kondo, J.; Chan, P.-Y.; Heller, E.; Jain, F. C.

    2018-02-01

    Site-specific self-assembled colloidal quantum dots (QDs) will deposit in two layers only on p-type substrate to form a QD superlattice (QDSL). The QDSL structure has been integrated into the floating gate of a nonvolatile memory component and has demonstrated promising results in multi-bit storage, ease of fabrication, and memory retention. Additionally, multi-valued logic devices and circuits have been created by using QDSL structures which demonstrated ternary and quaternary logic. With increasing use of site-specific self-assembled QDSLs, fundamental understanding of silicon and germanium QDSL charge storage capability, self-assembly on specific surfaces, uniform distribution, and mini-band formation has to be understood for successful implementation in devices. In this work, we investigate the differences in electron charge storage by building metal-oxide semiconductor (MOS) capacitors and using capacitance and voltage measurements to quantify the storage capabilities. The self-assembly process and distribution density of the QDSL is done by obtaining atomic force microscopy (AFM) results on line samples. Additionally, we present a summary of the theoretical density of states in each of the QDSLs.

  12. Low temperature synthesis and electrical characterization of germanium doped Ti-based nanocrystals for nonvolatile memory

    International Nuclear Information System (INIS)

    Feng, Li-Wei; Chang, Chun-Yen; Chang, Ting-Chang; Tu, Chun-Hao; Wang, Pai-Syuan; Lin, Chao-Cheng; Chen, Min-Chen; Huang, Hui-Chun; Gan, Der-Shin; Ho, New-Jin; Chen, Shih-Ching; Chen, Shih-Cheng

    2011-01-01

    Chemical and electrical characteristics of Ti-based nanocrystals containing germanium, fabricated by annealing the co-sputtered thin film with titanium silicide and germanium targets, were demonstrated for low temperature applications of nonvolatile memory. Formation and composition characteristics of nanocrystals (NCs) at various annealing temperatures were examined by transmission electron microscopy and X-ray photon-emission spectroscopy, respectively. It was observed that the addition of germanium (Ge) significantly reduces the proposed thermal budget necessary for Ti-based NC formation due to the rise of morphological instability and agglomeration properties during annealing. NC structures formed after annealing at 500 °C, and separated well at 600 °C annealing. However, it was also observed that significant thermal desorption of Ge atoms occurs at 600 °C due to the sublimation of formatted GeO phase and results in a serious decrease of memory window. Therefore, an approach to effectively restrain Ge thermal desorption is proposed by encapsulating the Ti-based trapping layer with a thick silicon oxide layer before 600 °C annealing. The electrical characteristics of data retention in the sample with the 600 °C annealing exhibited better performance than the 500 °C-annealed sample, a result associated with the better separation and better crystallization of the NC structures.

  13. Dependence of the organic nonvolatile memory performance on the location of ultra-thin Ag film

    International Nuclear Information System (INIS)

    Jiao Bo; Wu Zhaoxin; He Qiang; Mao Guilin; Hou Xun; Tian Yuan

    2010-01-01

    We demonstrated organic nonvolatile memory devices based on 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino] triphenylamine (m-MTDATA) inserted by an ultra-thin Ag film. The memory devices with different locations of ultra-thin Ag film in m-MTDATA were investigated, and it was found that the location of the Ag film could affect the performance of the organic memory, such as ON/OFF ratio, retention time and cycling endurance. When the Ag film was located at the ITO/m-MTDATA interface, the largest ON/OFF ratio (about 10 5 ) could be achieved, but the cycling endurance was poor. When the Ag film was located in the middle region of the m-MTDATA layer, the ON/OFF ratios came down by about 10 3 , but better performance of cycling endurance was exhibited. When the Ag film was located close to the Al electrode, the ON/OFF ratios and the retention time of this device decreased sharply and the bistable phenomenon almost disappeared. Our works show a simple approach to improve the performance of organic memory by adjusting the location of the metal film.

  14. Non-volatile memory devices with redox-active diruthenium molecular compound

    International Nuclear Information System (INIS)

    Pookpanratana, S; Zhu, H; Bittle, E G; Richter, C A; Li, Q; Hacker, C A; Natoli, S N; Ren, T

    2016-01-01

    Reduction-oxidation (redox) active molecules hold potential for memory devices due to their many unique properties. We report the use of a novel diruthenium-based redox molecule incorporated into a non-volatile Flash-based memory device architecture. The memory capacitor device structure consists of a Pd/Al 2 O 3 /molecule/SiO 2 /Si structure. The bulky ruthenium redox molecule is attached to the surface by using a ‘click’ reaction and the monolayer structure is characterized by x-ray photoelectron spectroscopy to verify the Ru attachment and molecular density. The ‘click’ reaction is particularly advantageous for memory applications because of (1) ease of chemical design and synthesis, and (2) provides an additional spatial barrier between the oxide/silicon to the diruthenium molecule. Ultraviolet photoelectron spectroscopy data identified the energy of the electronic levels of the surface before and after surface modification. The molecular memory devices display an unsaturated charge storage window attributed to the intrinsic properties of the redox-active molecule. Our findings demonstrate the strengths and challenges with integrating molecular layers within solid-state devices, which will influence the future design of molecular memory devices. (paper)

  15. Standard Test Method for Gravimetric Determination of Nonvolatile Residue from Cleanroom Gloves

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers the determination of solvent extractable nonvolatile residue (NVR) from gloves used in cleanrooms where spacecraft are assembled, cleaned, or tested. 1.2 The NVR of interest is that which can be extracted from gloves using a specified solvent that has been selected for its extracting qualities, or because it is representative of solvents used in the particular facility. Alternative solvents may be used, but since their use may result in different values being generated, they must be identified in the procedure data sheet. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Resistance Switching Characteristics in ZnO-Based Nonvolatile Memory Devices

    Directory of Open Access Journals (Sweden)

    Fu-Chien Chiu

    2013-01-01

    Full Text Available Bipolar resistance switching characteristics are demonstrated in Pt/ZnO/Pt nonvolatile memory devices. A negative differential resistance or snapback characteristic can be observed when the memory device switches from a high resistance state to a low resistance state due to the formation of filamentary conducting path. The dependence of pulse width and temperature on set/reset voltages was examined in this work. The exponentially decreasing trend of set/reset voltage with increasing pulse width is observed except when pulse width is larger than 1 s. Hence, to switch the ZnO memory devices, a minimum set/reset voltage is required. The set voltage decreases linearly with the temperature whereas the reset voltage is nearly temperature-independent. In addition, the ac cycling endurance can be over 106 switching cycles, whereas, the dependence of HRS/LRS resistance distribution indicates that a significant memory window closure may take place after about 102  dc switching cycles.

  17. Four-state non-volatile memory in a multiferroic spin filter tunnel junction

    Science.gov (United States)

    Ruan, Jieji; Li, Chen; Yuan, Zhoushen; Wang, Peng; Li, Aidong; Wu, Di

    2016-12-01

    We report a spin filter type multiferroic tunnel junction with a ferromagnetic/ferroelectric bilayer barrier. Memory functions of a spin filter magnetic tunnel junction and a ferroelectric tunnel junction are combined in this single device, producing four non-volatile resistive states that can be read out in a non-destructive manner. This concept is demonstrated in a LaNiO3/Pr0.8Ca0.2MnO3/BaTiO3/La0.7Sr0.3MnO3 all-oxide tunnel junction. The ferromagnetic insulator Pr0.8Ca0.2MnO3 serves as the spin filter and the ferromagnetic metal La0.7Sr0.3MnO3 is the spin analyzer. The ferroelectric polarization reversal in the BaTiO3 barrier switches the tunneling barrier height to produce a tunneling electroresistance. The ferroelectric switching also modulates the spin polarization and the spin filtering efficiency in Pr0.8Ca0.2MnO3.

  18. Quasi-unipolar pentacene films embedded with fullerene for non-volatile organic transistor memories

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Juhee; Lee, Sungpyo; Lee, Moo Hyung; Kang, Moon Sung, E-mail: mskang@ssu.ac.kr [Department of Chemical Engineering, Soongsil University, Seoul 156-743 (Korea, Republic of)

    2015-02-09

    Quasi-unipolar non-volatile organic transistor memory (NOTM) can combine the best characteristics of conventional unipolar and ambipolar NOTMs and, as a result, exhibit improved device performance. Unipolar NOTMs typically exhibit a large signal ratio between the programmed and erased current signals but also require a large voltage to program and erase the memory cells. Meanwhile, an ambipolar NOTM can be programmed and erased at lower voltages, but the resulting signal ratio is small. By embedding a discontinuous n-type fullerene layer within a p-type pentacene film, quasi-unipolar NOTMs are fabricated, of which the signal storage utilizes both electrons and holes while the electrical signal relies on only hole conduction. These devices exhibit superior memory performance relative to both pristine unipolar pentacene devices and ambipolar fullerene/pentacene bilayer devices. The quasi-unipolar NOTM exhibited a larger signal ratio between the programmed and erased states while also reducing the voltage required to program and erase a memory cell. This simple approach should be readily applicable for various combinations of advanced organic semiconductors that have been recently developed and thereby should make a significant impact on organic memory research.

  19. Scaling dependence of memory windows and different carrier charging behaviors in Si nanocrystal nonvolatile memory devices

    Science.gov (United States)

    Yu, Jie; Chen, Kun-ji; Ma, Zhong-yuan; Zhang, Xin-xin; Jiang, Xiao-fan; Wu, Yang-qing; Huang, Xin-fan; Oda, Shunri

    2016-09-01

    Based on the charge storage mode, it is important to investigate the scaling dependence of memory performance in silicon nanocrystal (Si-NC) nonvolatile memory (NVM) devices for its scaling down limit. In this work, we made eight kinds of test key cells with different gate widths and lengths by 0.13-μm node complementary metal oxide semiconductor (CMOS) technology. It is found that the memory windows of eight kinds of test key cells are almost the same of about 1.64 V @ ± 7 V/1 ms, which are independent of the gate area, but mainly determined by the average size (12 nm) and areal density (1.8 × 1011/cm2) of Si-NCs. The program/erase (P/E) speed characteristics are almost independent of gate widths and lengths. However, the erase speed is faster than the program speed of test key cells, which is due to the different charging behaviors between electrons and holes during the operation processes. Furthermore, the data retention characteristic is also independent of the gate area. Our findings are useful for further scaling down of Si-NC NVM devices to improve the performance and on-chip integration. Project supported by the State Key Development Program for Basic Research of China (Grant No. 2010CB934402) and the National Natural Science Foundation of China (Grant Nos. 11374153, 61571221, and 61071008).

  20. Inkjet-printing of non-volatile organic resistive devices and crossbar array structures

    Science.gov (United States)

    Sax, Stefan; Nau, Sebastian; Popovic, Karl; Bluemel, Alexander; Klug, Andreas; List-Kratochvil, Emil J. W.

    2015-09-01

    Due to the increasing demand for storage capacity in various electronic gadgets like mobile phones or tablets, new types of non-volatile memory devices have gained a lot of attention over the last few years. Especially multilevel conductance switching elements based on organic semiconductors are of great interest due to their relatively simple device architecture and their small feature size. Since organic semiconductors combine the electronic properties of inorganic materials with the mechanical characteristics of polymers, this class of materials is suitable for solution based large area device preparation techniques. Consequently, inkjet based deposition techniques are highly capable of facing preparation related challenges. By gradually replacing the evaporated electrodes with inkjet printed silver, the preparation related influence onto device performance parameters such as the ON/OFF ratio was investigated with IV measurements and high resolution transmission electron microscopy. Due to the electrode surface roughness the solvent load during the printing of the top electrode as well as organic layer inhomogeneity's the utilization in array applications is hampered. As a prototypical example a 1diode-1resistor element and a 2×2 subarray from 5×5 array matrix were fully characterized demonstrating the versatility of inkjet printing for device preparation.

  1. Thin PZT-Based Ferroelectric Capacitors on Flexible Silicon for Nonvolatile Memory Applications

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-04-24

    A flexible version of traditional thin lead zirconium titanate ((Pb1.1Zr0.48Ti0.52O3)-(PZT)) based ferroelectric random access memory (FeRAM) on silicon shows record performance in flexible arena. The thin PZT layer requires lower operational voltages to achieve coercive electric fields, reduces the sol-gel coating cycles required (i.e., more cost-effective), and, fabrication wise, is more suitable for further scaling of lateral dimensions to the nano-scale due to the larger feature size-to-depth aspect ratio (critical for ultra-high density non-volatile memory applications). Utilizing the inverse proportionality between substrate\\'s thickness and its flexibility, traditional PZT based FeRAM on silicon is transformed through a transfer-less manufacturable process into a flexible form that matches organic electronics\\' flexibility while preserving the superior performance of silicon CMOS electronics. Each memory cell in a FeRAM array consists of two main elements; a select/access transistor, and a storage ferroelectric capacitor. Flexible transistors on silicon have already been reported. In this work, we focus on the storage ferroelectric capacitors, and report, for the first time, its performance after transformation into a flexible version, and assess its key memory parameters while bent at 0.5 cm minimum bending radius.

  2. Graphene-ferroelectric metadevices for nonvolatile memory and reconfigurable logic-gate operations

    Science.gov (United States)

    Kim, Woo Young; Kim, Hyeon-Don; Kim, Teun-Teun; Park, Hyun-Sung; Lee, Kanghee; Choi, Hyun Joo; Lee, Seung Hoon; Son, Jaehyeon; Park, Namkyoo; Min, Bumki

    2016-01-01

    Memory metamaterials are artificial media that sustain transformed electromagnetic properties without persistent external stimuli. Previous memory metamaterials were realized with phase-change materials, such as vanadium dioxide or chalcogenide glasses, which exhibit memory behaviour with respect to electrically/optically induced thermal stimuli. However, they require a thermally isolated environment for longer retention or strong optical pump for phase-change. Here we demonstrate electrically programmable nonvolatile memory metadevices realised by the hybridization of graphene, a ferroelectric and meta-atoms/meta-molecules, and extend the concept further to establish reconfigurable logic-gate metadevices. For a memory metadevice having a single electrical input, amplitude, phase and even the polarization multi-states were clearly distinguishable with a retention time of over 10 years at room temperature. Furthermore, logic-gate functionalities were demonstrated with reconfigurable logic-gate metadevices having two electrical inputs, with each connected to separate ferroelectric layers that act as the multi-level controller for the doping level of the sandwiched graphene layer.

  3. Transport and Fatigue Properties of Ferroelectric Polymer P(VDF-TrFE) For Nonvolatile Memory Applications

    KAUST Repository

    Hanna, Amir

    2012-01-01

    injection and transport are believed to affect various properties of ferroelectric films such as remnant polarization values and polarization fatigue behavior.. Thus, this thesis aims to study charge injection in P(VDF-TrFE) and its transport properties as a

  4. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  5. Calcitonin Salmon Injection

    Science.gov (United States)

    Calcitonin salmon injection is used to treat osteoporosis in postmenopausal women. Osteoporosis is a disease that causes bones to weaken and break more easily. Calcitonin salmon injection is also used to treat Paget's disease ...

  6. Iron Dextran Injection

    Science.gov (United States)

    Iron dextran injection is used to treat iron-deficiency anemia (a lower than normal number of red blood cells ... treated with iron supplements taken by mouth. Iron dextran injection is in a class of medications called ...

  7. Aminocaproic Acid Injection

    Science.gov (United States)

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  8. Deoxycholic Acid Injection

    Science.gov (United States)

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  9. Cluster beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1978-01-01

    Areas of possible applications of cluster injection are discussed. The deposition inside the plasma of molecules, issued from the dissociation of the injected clusters, has been computed. Some empirical scaling laws for the penetration are given

  10. Antigen injection (image)

    Science.gov (United States)

    Leprosy is caused by the organism Mycobacterium leprae . The leprosy test involves injection of an antigen just under ... if your body has a current or recent leprosy infection. The injection site is labeled and examined ...

  11. Time-resolved two-photon photoemission at the Si(001)-surface. Hot electron dynamics and two-dimensional Fano resonance; Zeitaufgeloeste Zweiphotonen-Photoemission an der Si(001)-Oberflaeche. Dynamik heisser Elektronen und zweidimensionaler Fano-Effekt

    Energy Technology Data Exchange (ETDEWEB)

    Eickhoff, Christian

    2010-10-27

    By combining ultrafast laser excitation with energy-, angle- and time-resolved twophoton photoemission (2PPE), the electronic properties of bulk silicon and the Si(001) surface are investigated in this thesis. A custom-built laser- and UHV-systemequipped with a display type 2D-CCD-detector gives new insight into the relaxation dynamics of excited carriers on a femtosecond timescale. The bandgap between occupied valence bands and unoccupied conduction bands characteristically influences the dynamics of excited electrons in the bulk, as well as in surface states and resonances. For the electron-phonon interaction this leads to the formation of a bottleneck during the relaxation of hot electrons in the conduction band, which maintains the elevated electronic temperature for several picoseconds. During relaxation, excited electrons also scatter from the conduction band into the unoccupied dangling-bond surface state D{sub down}. Depending on the excitation density this surface recombination is dominated by electron-electron- or electron-phonon scattering. The relaxation of the carriers in the D{sub down}-band is again slowed down by the formation of a bottleneck in electron-phonon coupling. Furthermore, the new laser system has allowed detection of the Rydberg-like series of image-potential resonances on the Si(001)-surface. It is shown that the lifetime of these image-potential resonances in front of the semiconducting surface exhibits the same behavior as those in front of metallic surfaces. Moreover the electron-phonon coupling in the first image-potential resonance was investigated and compared to the D{sub down}-surface state. For the first time, Fano-type lineprofiles are demonstrated and analyzed in a 2PPEprocess on a surface. Tuning the photon energy of the pump-laser across the resonance between the occupied dangling-bond state D{sub up}, and the unoccupied image-potential resonance n=1, reveals a clear intensity variation that can be successfully described

  12. Investigation of High-k Dielectrics and Metal Gate Electrodes for Non-volatile Memory Applications

    Science.gov (United States)

    Jayanti, Srikant

    Due to the increasing demand of non-volatile flash memories in the portable electronics, the device structures need to be scaled down drastically. However, the scalability of traditional floating gate structures beyond 20 nm NAND flash technology node is uncertain. In this regard, the use of metal gates and high-k dielectrics as the gate and interpoly dielectrics respectively, seem to be promising substitutes in order to continue the flash scaling beyond 20nm. Furthermore, research of novel memory structures to overcome the scaling challenges need to be explored. Through this work, the use of high-k dielectrics as IPDs in a memory structure has been studied. For this purpose, IPD process optimization and barrier engineering were explored to determine and improve the memory performance. Specifically, the concept of high-k / low-k barrier engineering was studied in corroboration with simulations. In addition, a novel memory structure comprising a continuous metal floating gate was investigated in combination with high-k blocking oxides. Integration of thin metal FGs and high-k dielectrics into a dual floating gate memory structure to result in both volatile and non-volatile modes of operation has been demonstrated, for plausible application in future unified memory architectures. The electrical characterization was performed on simple MIS/MIM and memory capacitors, fabricated through CMOS compatible processes. Various analytical characterization techniques were done to gain more insight into the material behavior of the layers in the device structure. In the first part of this study, interfacial engineering was investigated by exploring La2O3 as SiO2 scavenging layer. Through the silicate formation, the consumption of low-k SiO2 was controlled and resulted in a significant improvement in dielectric leakage. The performance improvement was also gauged through memory capacitors. In the second part of the study, a novel memory structure consisting of continuous metal FG

  13. Experimental study of hot electrons propagation and energy deposition in solid or laser-shock compressed targets: applications to fast igniter; Etude experimentale de la propagation et du depot d'energie d'electrons rapides dans une cible solide ou comprimee par choc laser: application a l'allumeur rapide

    Energy Technology Data Exchange (ETDEWEB)

    Pisani, F

    2000-02-15

    In the fast igniter scheme, a recent approach proposed for the inertial confinement fusion, the idea is to dissociate the fuel ignition phase from its compression. The ignition phase would be then achieved by means of an external energy source: a fast electron beam generated by the interaction with an ultra-intense laser. The main goal of this work is to study the mechanisms of the hot electron energy transfer to the compressed fuel. We intent in particular to study the role of the electric and collisional effects involved in the hot electron propagation in a medium with properties similar to the compressed fuel. We carried out two experiments, one at the Vulcan laser facility (England) and the second one at the new LULI 100 TW laser (France). During the first experiment, we obtained the first results on the hot electron propagation in a dense and hot plasma. The innovating aspect of this work was in particular the use of the laser-shock technique to generate high pressures, allowing the strongly correlated and degenerated plasma to be created. The role of the electric and magnetic effects due to the space charge associated with the fast electron beam has been investigated in the second experiment. Here we studied the propagation in materials with different electrical characteristics: an insulator and a conductor. The analysis of the results showed that only by taking into account simultaneously the two propagation mechanisms (collisions and electric effects) a correct treatment of the energy deposition is possible. We also showed the importance of taking into account the induced modifications due to the electrons beam crossing the target, especially the induced heating. (author)

  14. Long-term studies on the effects of nonvolatile organic compounds on porous media surface areas.

    Science.gov (United States)

    Khachikian, Crist S; Harmon, Thomas C

    2002-01-01

    This paper investigates the long-term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption-desorption techniques. A field-contaminated sand affected by lamp-black material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean-MS values during the 700-h aging period, but achieved the clean values only after pentane extraction or heating at 60 degrees C. Heating at 50 degrees C failed to achieve a similar recovery of the clean-MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100 degrees C produced a slight decrease in surface area and mass while aging at 250 degrees C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment.

  15. Studying the fate of non-volatile organic compounds in a commercial plasma air purifier

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Stefan [ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich (Switzerland); Seiler, Cornelia; Gerecke, Andreas C. [Swiss Federal Laboratories for Material Science and Technology (EMPA), CH-8600 Dübendorf (Switzerland); Hächler, Herbert [University of Zürich, Institute for Food Safety and Hygiene, National Centre for Enteropathogenic Bacteria and Listeria (NENT), CH-8057 Zürich (Switzerland); Hilbi, Hubert [Ludwig-Maximilians-Universität München Max von Pettenkofer-Institut, D-80336 München (Germany); Frey, Joachim [University of Bern, Institute for Veterinary Bacteriology, CH-3001 Bern (Switzerland); Weidmann, Simon; Meier, Lukas; Berchtold, Christian [ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich (Switzerland); Zenobi, Renato, E-mail: zenobi@org.chem.ethz.ch [ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich (Switzerland)

    2013-07-15

    Highlights: • Degradation of environmental toxins, a protein, and bioparticles were studied. • A commercial air purifier based on a cold plasma was used. • Passage through the device reduced the concentration of the compounds/particles. • Deposition inside the plasma air purifier was the main removal process. -- Abstract: Degradation of non-volatile organic compounds–environmental toxins (methyltriclosane and phenanthrene), bovine serum albumin, as well as bioparticles (Legionella pneumophila, Bacillus subtilis, and Bacillus anthracis)–in a commercially available plasma air purifier based on a cold plasma was studied in detail, focusing on its efficiency and on the resulting degradation products. This system is capable of handling air flow velocities of up to 3.0 m s{sup −1} (3200 L min{sup −1}), much higher than other plasma-based reactors described in the literature, which generally are limited to air flow rates below 10 L min{sup −1}. Mass balance studies consistently indicated a reduction in concentration of the compounds/particles after passage through the plasma air purifier, 31% for phenanthrene, 17% for methyltriclosane, and 80% for bovine serum albumin. L. pneumophila did not survive passage through the plasma air purifier, and cell counts of aerosolized spores of B. subtilis and B. anthracis were reduced by 26- and 15-fold, depending on whether it was run at 10 Hz or 50 Hz, respectively. However rather than chemical degradation, deposition on the inner surfaces of the plasma air purifier occured. Our interpretation is that putative “degradation” efficiencies were largely due to electrostatic precipitation rather than to decomposition into smaller molecules.

  16. Novel ferroelectric capacitor for non-volatile memory storage and biomedical tactile sensor applications

    International Nuclear Information System (INIS)

    Liu, Shi Yang; Chua, Lynn; Tan, Kian Chuan; Valavan, S.E.

    2010-01-01

    We report on novel ferroelectric thin film compositions for use in non-volatile memory storage and biomedical tactile sensor applications. The lead zirconate titanate (PZT) composition was modified by lanthanum (La 3+ ) (PLZT) and vanadium (V 5+ ) (PZTV, PLZTV) doping. Hybrid films with PZTV and PLZTV as top layers are also made using seed layers of differing compositions using sol-gel and spin coating methods. La 3+ doping decreased the coercive field, polarization and leakage current, while increasing the relative permittivity. V 5+ doping, while having similar effects, results in an enhanced polarization, with comparable dielectric loss characteristics. Complex doping of both La 3+ and V 5+ in PLZTV, while reducing the polarization relative to PZTV, significantly decreases the coercive field. Hybrid films have a greater uniformity of grain formation than non-hybrid films, thus decreasing the coercive field, leakage current and polarization fatigue while increasing the relative permittivity. Analysis using X-ray diffraction (XRD) verified the retention of the PZT perovskite structure in the novel films. PLZT/PZTV has been identified as an optimal ferroelectric film composition due to its desirable ferroelectric, fatigue and dielectric properties, including the highest observed remnant polarization (P r ) of ∼ 25 μC/cm 2 , saturation polarization (P sat ) of ∼ 58 μC/cm 2 and low coercive field (E c ) of ∼ 60 kV/cm at an applied field of ∼ 1000 kV/cm, as well as a low leakage current density of ∼ 10 -5 A/cm 2 at 500 kV/cm and fatigue resistance of up to ∼ 10 10 switching cycles.

  17. A Compute Capable SSD Architecture for Next-Generation Non-volatile Memories

    Energy Technology Data Exchange (ETDEWEB)

    De, Arup [Univ. of California, San Diego, CA (United States)

    2014-01-01

    Existing storage technologies (e.g., disks and ash) are failing to cope with the processor and main memory speed and are limiting the overall perfor- mance of many large scale I/O or data-intensive applications. Emerging fast byte-addressable non-volatile memory (NVM) technologies, such as phase-change memory (PCM), spin-transfer torque memory (STTM) and memristor are very promising and are approaching DRAM-like performance with lower power con- sumption and higher density as process technology scales. These new memories are narrowing down the performance gap between the storage and the main mem- ory and are putting forward challenging problems on existing SSD architecture, I/O interface (e.g, SATA, PCIe) and software. This dissertation addresses those challenges and presents a novel SSD architecture called XSSD. XSSD o oads com- putation in storage to exploit fast NVMs and reduce the redundant data tra c across the I/O bus. XSSD o ers a exible RPC-based programming framework that developers can use for application development on SSD without dealing with the complication of the underlying architecture and communication management. We have built a prototype of XSSD on the BEE3 FPGA prototyping system. We implement various data-intensive applications and achieve speedup and energy ef- ciency of 1.5-8.9 and 1.7-10.27 respectively. This dissertation also compares XSSD with previous work on intelligent storage and intelligent memory. The existing ecosystem and these new enabling technologies make this system more viable than earlier ones.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-11-01

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

  19. Occurence and dietary exposure of volatile and non-volatile N-Nitrosamines in processed meat products

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange; Duedahl-Olesen, Lene; Granby, Kit

    Nitrite and nitrate have for many decades been used for preservation of meat. However, nitrite can react with secondary amines in meat to form N-Nitrosamines (NAs), many of which have been shown to be genotoxic1 . The use of nitrite therefore ought to be limited as much as possible. To maintain...... a high level of consumer protection Denmark obtains National low limits of the nitrite use in meat products. An estimation of the dietary exposure to volatile NAs (VNA) and non-volatile NAs (NVNA) is necessary when performing a risk assessment of the use of nitrite and nitrate for meat preservation....

  20. Subthreshold-swing-adjustable tunneling-field-effect-transistor-based random-access memory for nonvolatile operation

    Science.gov (United States)

    Huh, In; Cheon, Woo Young; Choi, Woo Young

    2016-04-01

    A subthreshold-swing-adjustable tunneling-field-effect-transistor-based random-access memory (SAT RAM) has been proposed and fabricated for low-power nonvolatile memory applications. The proposed SAT RAM cell demonstrates adjustable subthreshold swing (SS) depending on stored information: small SS in the erase state ("1" state) and large SS in the program state ("0" state). Thus, SAT RAM cells can achieve low read voltage (Vread) with a large memory window in addition to the effective suppression of ambipolar behavior. These unique features of the SAT RAM are originated from the locally stored charge, which modulates the tunneling barrier width (Wtun) of the source-to-channel tunneling junction.

  1. Memory characteristics of silicon nitride with silicon nanocrystals as a charge trapping layer of nonvolatile memory devices

    International Nuclear Information System (INIS)

    Choi, Sangmoo; Yang, Hyundeok; Chang, Man; Baek, Sungkweon; Hwang, Hyunsang; Jeon, Sanghun; Kim, Juhyung; Kim, Chungwoo

    2005-01-01

    Silicon nitride with silicon nanocrystals formed by low-energy silicon plasma immersion ion implantation has been investigated as a charge trapping layer of a polycrystalline silicon-oxide-nitride-oxide-silicon-type nonvolatile memory device. Compared with the control sample without silicon nanocrystals, silicon nitride with silicon nanocrystals provides excellent memory characteristics, such as larger width of capacitance-voltage hysteresis, higher program/erase speed, and lower charge loss rate at elevated temperature. These improved memory characteristics are derived by incorporation of silicon nanocrystals into the charge trapping layer as additional accessible charge traps with a deeper effective trap energy level

  2. SQL injection detection system

    OpenAIRE

    Vargonas, Vytautas

    2017-01-01

    SQL injection detection system Programmers do not always ensure security of developed systems. That is why it is important to look for solutions outside being reliant on developers. In this work SQL injection detection system is proposed. The system analyzes HTTP request parameters and detects intrusions. It is based on unsupervised machine learning. Trained by regular request data system detects outlier user parameters. Since training is not reliant on previous knowledge of SQL injections, t...

  3. A New Concept for Non-Volatile Memory: The Electric-Pulse Induced Resistive Change Effect in Colossal Magnetoresistive Thin Films

    Science.gov (United States)

    Liu, S. Q.; Wu, N. J.; Ignatiev, A.

    2001-01-01

    A novel electric pulse-induced resistive change (EPIR) effect has been found in thin film colossal magnetoresistive (CMR) materials, and has shown promise for the development of resistive, nonvolatile memory. The EPIR effect is induced by the application of low voltage (resistance of the thin film sample depending on pulse polarity. The sample resistance change has been shown to be over two orders of magnitude, and is nonvolatile after pulsing. The sample resistance can also be changed through multiple levels - as many as 50 have been shown. Such a device can provide a way for the development of a new kind of nonvolatile multiple-valued memory with high density, fast write/read speed, low power-consumption, and potential high radiation-hardness.

  4. High-Performance Nonvolatile Organic Field-Effect Transistor Memory Based on Organic Semiconductor Heterostructures of Pentacene/P13/Pentacene as Both Charge Transport and Trapping Layers.

    Science.gov (United States)

    Li, Wen; Guo, Fengning; Ling, Haifeng; Zhang, Peng; Yi, Mingdong; Wang, Laiyuan; Wu, Dequn; Xie, Linghai; Huang, Wei

    2017-08-01

    Nonvolatile organic field-effect transistor (OFET) memory devices based on pentacene/ N , N '-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13)/pentacene trilayer organic heterostructures have been proposed. The discontinuous n-type P13 embedded in p-type pentacene layers can not only provide electrons in the semiconductor layer that facilitates electron trapping process; it also works as charge trapping sites, which is attributed to the quantum well-like pentacene/P13/pentacene organic heterostructures. The synergistic effects of charge trapping in the discontinuous P13 and the charge-trapping property of the poly(4-vinylphenol) (PVP) layer remarkably improve the memory performance. In addition, the trilayer organic heterostructures have also been successfully applied to multilevel and flexible nonvolatile memory devices. The results provide a novel design strategy to achieve high-performance nonvolatile OFET memory devices and allow potential applications for different combinations of various organic semiconductor materials in OFET memory.

  5. Piezoelectric Injection Systems

    Science.gov (United States)

    Mock, R.; Lubitz, K.

    The origin of direct injection can be doubtlessly attributed to Rudolf Diesel who used air assisted injection for fuel atomisation in his first self-ignition engine. Although it became apparent already at that time that direct injection leads to reduced specific fuel consumption compared to other methods of fuel injection, it was not used in passenger cars for the moment because of its disadvantageous noise generation as the requirements with regard to comfort were seen as more important than a reduced specific consumption.

  6. Urinary incontinence - injectable implant

    Science.gov (United States)

    ... repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... and disorders: physiology of micturition, voiding dysfunction, urinary incontinence, urinary tract infections, and painful bladder syndrome. In: Lobo ...

  7. Analytical techniques and method validation for the measurement of selected semivolatile and nonvolatile organofluorochemicals in air.

    Science.gov (United States)

    Reagen, William K; Lindstrom, Kent R; Thompson, Kathy L; Flaherty, John M

    2004-09-01

    The widespread use of semi- and nonvolatile organofluorochemicals in industrial facilities, concern about their persistence, and relatively recent advancements in liquid chromatography/mass spectrometry (LC/MS) technology have led to the development of new analytical methods to assess potential worker exposure to airborne organofluorochemicals. Techniques were evaluated for the determination of 19 organofluorochemicals and for total fluorine in ambient air samples. Due to the potential biphasic nature of most of these fluorochemicals when airborne, Occupational Safety and Health Administration (OSHA) versatile sampler (OVS) tubes were used to simultaneously trap fluorochemical particulates and vapors from workplace air. Analytical methods were developed for OVS air samples to quantitatively analyze for total fluorine using oxygen bomb combustion/ion selective electrode and for 17 organofluorochemicals using LC/MS and gas chromatography/mass spectrometry (GC/MS). The experimental design for this validation was based on the National Institute of Occupational Safety and Health (NIOSH) Guidelines for Air Sampling and Analytical Method Development and Evaluation, with some revisions of the experimental design. The study design incorporated experiments to determine analytical recovery and stability, sampler capacity, the effect of some environmental parameters on recoveries, storage stability, limits of detection, precision, and accuracy. Fluorochemical mixtures were spiked onto each OVS tube over a range of 0.06-6 microg for each of 12 compounds analyzed by LC/MS and 0.3-30 microg for 5 compounds analyzed by GC/MS. These ranges allowed reliable quantitation at 0.001-0.1 mg/m3 in general for LC/MS analytes and 0.005-0.5 mg/m3 for GC/MS analytes when 60 L of air are sampled. The organofluorochemical exposure guideline (EG) is currently 0.1 mg/m3 for many analytes, with one exception being ammonium perfluorooctanoate (EG is 0.01 mg/m3). Total fluorine results may be used

  8. Size distributions of non-volatile particle residuals (Dp<800 nm at a rural site in Germany and relation to air mass origin

    Directory of Open Access Journals (Sweden)

    T. Tuch

    2007-11-01

    Full Text Available Atmospheric aerosol particle size distributions at a continental background site in Eastern Germany were examined for a one-year period. Particles were classified using a twin differential mobility particle sizer in a size range between 3 and 800 nm. As a novelty, every second measurement of this experiment involved the removal of volatile chemical compounds in a thermodenuder at 300°C. This concept allowed to quantify the number size distribution of non-volatile particle cores – primarily associated with elemental carbon, and to compare this to the original non-conditioned size distribution. As a byproduct of the volatility analysis, new particles originating from nucleation inside the thermodenuder can be observed, however, overwhelmingly at diameters below 6 nm. Within the measurement uncertainty, every particle down to particle sizes of 15 nm is concluded to contain a non-volatile core. The volume fraction of non-volatile particulate matter (non-conditioned diameter < 800 nm varied between 10 and 30% and was largely consistent with the experimentally determined mass fraction of elemental carbon. The average size of the non-volatile particle cores was estimated as a function of original non-conditioned size using a summation method, which showed that larger particles (>200 nm contained more non-volatile compounds than smaller particles (<50 nm, thus indicating a significantly different chemical composition. Two alternative air mass classification schemes based on either, synoptic chart analysis (Berliner Wetterkarte or back trajectories showed that the volume and number fraction of non-volatile cores depended less on air mass than the total particle number concentration. In all air masses, the non-volatile size distributions showed a more and a less volatile ("soot" mode, the latter being located at about 50 nm. During unstable conditions and in maritime air masses, smaller values were observed compared to stable or continental conditions

  9. Nonvolatile “AND,” “OR,” and “NOT” Boolean logic gates based on phase-change memory

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Zhong, Y. P.; Deng, Y. F.; Zhou, Y. X.; Xu, L.; Miao, X. S., E-mail: miaoxs@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology (HUST), Wuhan 430074 (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-12-21

    Electronic devices or circuits that can implement both logic and memory functions are regarded as the building blocks for future massive parallel computing beyond von Neumann architecture. Here we proposed phase-change memory (PCM)-based nonvolatile logic gates capable of AND, OR, and NOT Boolean logic operations verified in SPICE simulations and circuit experiments. The logic operations are parallel computing and results can be stored directly in the states of the logic gates, facilitating the combination of computing and memory in the same circuit. These results are encouraging for ultralow-power and high-speed nonvolatile logic circuit design based on novel memory devices.

  10. Nonvolatile “AND,” “OR,” and “NOT” Boolean logic gates based on phase-change memory

    International Nuclear Information System (INIS)

    Li, Y.; Zhong, Y. P.; Deng, Y. F.; Zhou, Y. X.; Xu, L.; Miao, X. S.

    2013-01-01

    Electronic devices or circuits that can implement both logic and memory functions are regarded as the building blocks for future massive parallel computing beyond von Neumann architecture. Here we proposed phase-change memory (PCM)-based nonvolatile logic gates capable of AND, OR, and NOT Boolean logic operations verified in SPICE simulations and circuit experiments. The logic operations are parallel computing and results can be stored directly in the states of the logic gates, facilitating the combination of computing and memory in the same circuit. These results are encouraging for ultralow-power and high-speed nonvolatile logic circuit design based on novel memory devices

  11. A hybrid magnetic/complementary metal oxide semiconductor three-context memory bit cell for non-volatile circuit design

    International Nuclear Information System (INIS)

    Jovanović, B.; Brum, R. M.; Torres, L.

    2014-01-01

    After decades of continued scaling to the beat of Moore's law, it now appears that conventional silicon based devices are approaching their physical limits. In today's deep-submicron nodes, a number of short-channel and quantum effects are emerging that affect the manufacturing process, as well as, the functionality of the microelectronic systems-on-chip. Spintronics devices that exploit both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, are promising solutions to circumvent these scaling threats. Being compatible with the CMOS technology, such devices offer a promising synergy of radiation immunity, infinite endurance, non-volatility, increased density, etc. In this paper, we present a hybrid (magnetic/CMOS) cell that is able to store and process data both electrically and magnetically. The cell is based on perpendicular spin-transfer torque magnetic tunnel junctions (STT-MTJs) and is suitable for use in magnetic random access memories and reprogrammable computing (non-volatile registers, processor cache memories, magnetic field-programmable gate arrays, etc). To demonstrate the potential our hybrid cell, we physically implemented a small hybrid memory block using 45 nm × 45 nm round MTJs for the magnetic part and 28 nm fully depleted silicon on insulator (FD-SOI) technology for the CMOS part. We also report the cells measured performances in terms of area, robustness, read/write speed and energy consumption

  12. Novel Quantum Dot Gate FETs and Nonvolatile Memories Using Lattice-Matched II-VI Gate Insulators

    Science.gov (United States)

    Jain, F. C.; Suarez, E.; Gogna, M.; Alamoody, F.; Butkiewicus, D.; Hohner, R.; Liaskas, T.; Karmakar, S.; Chan, P.-Y.; Miller, B.; Chandy, J.; Heller, E.

    2009-08-01

    This paper presents the successful use of ZnS/ZnMgS and other II-VI layers (lattice-matched or pseudomorphic) as high- k gate dielectrics in the fabrication of quantum dot (QD) gate Si field-effect transistors (FETs) and nonvolatile memory structures. Quantum dot gate FETs and nonvolatile memories have been fabricated in two basic configurations: (1) monodispersed cladded Ge nanocrystals (e.g., GeO x -cladded-Ge quantum dots) site-specifically self-assembled over the lattice-matched ZnMgS gate insulator in the channel region, and (2) ZnTe-ZnMgTe quantum dots formed by self-organization, using metalorganic chemical vapor-phase deposition (MOCVD), on ZnS-ZnMgS gate insulator layers grown epitaxially on Si substrates. Self-assembled GeO x -cladded Ge QD gate FETs, exhibiting three-state behavior, are also described. Preliminary results on InGaAs-on-InP FETs, using ZnMgSeTe/ZnSe gate insulator layers, are presented.

  13. Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

    KAUST Repository

    Semple, James

    2017-01-02

    Electronic memory cells are of critical importance in modern-day computing devices, including emerging technology sectors such as large-area printed electronics. One technology that has being receiving significant interest in recent years is resistive switching primarily due to its low dimensionality and nonvolatility. Here, we describe the development of resistive switching memory device arrays based on empty aluminum nanogap electrodes. By employing adhesion lithography, a low-temperature and large-area compatible nanogap fabrication technique, dense arrays of memory devices are demonstrated on both rigid and flexible plastic substrates. As-prepared devices exhibit nonvolatile memory operation with stable endurance, resistance ratios >10⁴ and retention times of several months. An intermittent analysis of the electrode microstructure reveals that controlled resistive switching is due to migration of metal from the electrodes into the nanogap under the application of an external electric field. This alternative form of resistive random access memory is promising for use in emerging sectors such as large-area electronics as well as in electronics for harsh environments, e.g., space, high/low temperature, magnetic influences, radiation, vibration, and pressure.

  14. Solution-Processed Wide-Bandgap Organic Semiconductor Nanostructures Arrays for Nonvolatile Organic Field-Effect Transistor Memory.

    Science.gov (United States)

    Li, Wen; Guo, Fengning; Ling, Haifeng; Liu, Hui; Yi, Mingdong; Zhang, Peng; Wang, Wenjun; Xie, Linghai; Huang, Wei

    2018-01-01

    In this paper, the development of organic field-effect transistor (OFET) memory device based on isolated and ordered nanostructures (NSs) arrays of wide-bandgap (WBG) small-molecule organic semiconductor material [2-(9-(4-(octyloxy)phenyl)-9H-fluoren-2-yl)thiophene]3 (WG 3 ) is reported. The WG 3 NSs are prepared from phase separation by spin-coating blend solutions of WG 3 /trimethylolpropane (TMP), and then introduced as charge storage elements for nonvolatile OFET memory devices. Compared to the OFET memory device with smooth WG 3 film, the device based on WG 3 NSs arrays exhibits significant improvements in memory performance including larger memory window (≈45 V), faster switching speed (≈1 s), stable retention capability (>10 4 s), and reliable switching properties. A quantitative study of the WG 3 NSs morphology reveals that enhanced memory performance is attributed to the improved charge trapping/charge-exciton annihilation efficiency induced by increased contact area between the WG 3 NSs and pentacene layer. This versatile solution-processing approach to preparing WG 3 NSs arrays as charge trapping sites allows for fabrication of high-performance nonvolatile OFET memory devices, which could be applicable to a wide range of WBG organic semiconductor materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

    KAUST Repository

    Semple, James; Wyatt-Moon, Gwenhivir; Georgiadou, Dimitra G.; McLachlan, Martyn A.; Anthopoulos, Thomas D.

    2017-01-01

    Electronic memory cells are of critical importance in modern-day computing devices, including emerging technology sectors such as large-area printed electronics. One technology that has being receiving significant interest in recent years is resistive switching primarily due to its low dimensionality and nonvolatility. Here, we describe the development of resistive switching memory device arrays based on empty aluminum nanogap electrodes. By employing adhesion lithography, a low-temperature and large-area compatible nanogap fabrication technique, dense arrays of memory devices are demonstrated on both rigid and flexible plastic substrates. As-prepared devices exhibit nonvolatile memory operation with stable endurance, resistance ratios >10⁴ and retention times of several months. An intermittent analysis of the electrode microstructure reveals that controlled resistive switching is due to migration of metal from the electrodes into the nanogap under the application of an external electric field. This alternative form of resistive random access memory is promising for use in emerging sectors such as large-area electronics as well as in electronics for harsh environments, e.g., space, high/low temperature, magnetic influences, radiation, vibration, and pressure.

  16. A hybrid magnetic/complementary metal oxide semiconductor three-context memory bit cell for non-volatile circuit design

    Energy Technology Data Exchange (ETDEWEB)

    Jovanović, B., E-mail: bojan.jovanovic@lirmm.fr, E-mail: lionel.torres@lirmm.fr; Brum, R. M.; Torres, L. [LIRMM—University of Montpellier 2/UMR CNRS 5506, 161 Rue Ada, 34095 Montpellier (France)

    2014-04-07

    After decades of continued scaling to the beat of Moore's law, it now appears that conventional silicon based devices are approaching their physical limits. In today's deep-submicron nodes, a number of short-channel and quantum effects are emerging that affect the manufacturing process, as well as, the functionality of the microelectronic systems-on-chip. Spintronics devices that exploit both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, are promising solutions to circumvent these scaling threats. Being compatible with the CMOS technology, such devices offer a promising synergy of radiation immunity, infinite endurance, non-volatility, increased density, etc. In this paper, we present a hybrid (magnetic/CMOS) cell that is able to store and process data both electrically and magnetically. The cell is based on perpendicular spin-transfer torque magnetic tunnel junctions (STT-MTJs) and is suitable for use in magnetic random access memories and reprogrammable computing (non-volatile registers, processor cache memories, magnetic field-programmable gate arrays, etc). To demonstrate the potential our hybrid cell, we physically implemented a small hybrid memory block using 45 nm × 45 nm round MTJs for the magnetic part and 28 nm fully depleted silicon on insulator (FD-SOI) technology for the CMOS part. We also report the cells measured performances in terms of area, robustness, read/write speed and energy consumption.

  17. The effects of biodiesels on semivolatile and nonvolatile particulate matter emissions from a light-duty diesel engine.

    Science.gov (United States)

    Cheng, Yuan; Li, Shao-Meng; Liggio, John; Hayden, Katherine; Han, Yuemei; Stroud, Craig; Chan, Tak; Poitras, Marie-Josée

    2017-11-01

    Semivolatile organic compounds (SVOCs) represent a dominant category of secondary organic aerosol precursors that are increasingly included in air quality models. In the present study, an experimental system was developed and applied to a light-duty diesel engine to determine the emission factors of particulate SVOCs (pSVOCs) and nonvolatile particulate matter (PM) components at dilution ratios representative of ambient conditions. The engine was tested under three steady-state operation modes, using ultra-low-sulfur diesel (ULSD), three types of pure biodiesels and their blends with ULSD. For ULSD, the contribution of pSVOCs to total particulate organic matter (POM) mass in the engine exhaust ranged between 21 and 85%. Evaporation of pSVOCs from the diesel particles during dilution led to decreases in the hydrogen to carbon ratio of POM and the PM number emission factor of the particles. Substituting biodiesels for ULSD could increase pSVOCs emissions but brought on large reductions in black carbon (BC) emissions. Among the biodiesels tested, tallow/used cooking oil (UCO) biodiesel showed advantages over soybean and canola biodiesels in terms of both pSVOCs and nonvolatile PM emissions. It is noteworthy that PM properties, such as particle size and BC mass fraction, differed substantially between emissions from conventional diesel and biodiesels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Electron injection in microtron

    International Nuclear Information System (INIS)

    Axinescu, S.

    1977-01-01

    A review of the methods of injecting electrons in the microtron is presented. A special attention is paid to efficient injection systems developed by Wernholm and Kapitza. A comparison of advantages and disadvantages of both systems is made in relation to the purpose of the microtron. (author)

  19. Glenohumeral Joint Injections

    Science.gov (United States)

    Gross, Christopher; Dhawan, Aman; Harwood, Daniel; Gochanour, Eric; Romeo, Anthony

    2013-01-01

    Context: Intra-articular injections into the glenohumeral joint are commonly performed by musculoskeletal providers, including orthopaedic surgeons, family medicine physicians, rheumatologists, and physician assistants. Despite their frequent use, there is little guidance for injectable treatments to the glenohumeral joint for conditions such as osteoarthritis, adhesive capsulitis, and rheumatoid arthritis. Evidence Acquisition: We performed a comprehensive review of the available literature on glenohumeral injections to help clarify the current evidence-based practice and identify deficits in our understanding. We searched MEDLINE (1948 to December 2011 [week 1]) and EMBASE (1980 to 2011 [week 49]) using various permutations of intra-articular injections AND (corticosteroid OR hyaluronic acid) and (adhesive capsulitis OR arthritis). Results: We identified 1 and 7 studies that investigated intra-articular corticosteroid injections for the treatment of osteoarthritis and adhesive capsulitis, respectively. Two and 3 studies investigated the use of hyaluronic acid in osteoarthritis and adhesive capsulitis, respectively. One study compared corticosteroids and hyaluronic acid injections in the treatment of osteoarthritis, and another discussed adhesive capsulitis. Conclusion: Based on existing studies and their level of evidence, there is only expert opinion to guide corticosteroid injection for osteoarthritis as well as hyaluronic acid injection for osteoarthritis and adhesive capsulitis. PMID:24427384

  20. Dimethyl Ether Injection Studies

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.; Glensvig, Michael; Abata, Duane L.

    1998-01-01

    A series of preliminary investigations has been performed in order to investigate the behavior of DME in a diesel injection environment. These studies have in-cluded visual observations of the spray penetration and angles for high pressure injection into Nitrogen using conventional jerk pump inje...

  1. THE RHIC INJECTION SYSTEM.

    Energy Technology Data Exchange (ETDEWEB)

    FISCHER,W.; GLENN,J.W.; MACKAY,W.W.; PTITSIN,V.; ROBINSON,T.G.; TSOUPAS,N.

    1999-03-29

    The RHIC injection system has to transport beam from the AGS-to-RHIC transfer line onto the closed orbits of the RHIC Blue and Yellow rings. This task can be divided into three problems. First, the beam has to be injected into either ring. Second, once injected the beam needs to be transported around the ring for one turn. Third, the orbit must be closed and coherent beam oscillations around the closed orbit should be minimized. We describe our solutions for these problems and report on system tests conducted during the RHIC Sextant test performed in 1997. The system will be fully commissioned in 1999.

  2. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    2014-01-01

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject......We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...

  3. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject......We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...

  4. The analysis of semi-volatile and non-volatile petroleum hydrocarbons in a soil/sediment matrix by capillary column gas chromatography/flame ionization detection (GC/FID)

    International Nuclear Information System (INIS)

    George, J.E. III; Thoma, J.J.; Hastings, M.

    1990-01-01

    A comprehensive analysis for semi-volatile and non-volatile fractions of petroleum hydrocarbons can be achieved by a solvent extraction/concentration techniques that will effectively extract these high molecular weight fractions from a soil matrix. The prepared extract is then injected directly into a gas chromatograph equipped with a capillary column and flame ionization detector. This technique applies to the following types of commercially available petroleum hydrocarbons: Diesel Nos. 2,4,5, and 6, fuel oils and several grades of lubrication oil. The identification of a particular petroleum hydrocarbon is determined visually by comparison of the samples with known hydrocarbon standards. Accurate quantitation of the chromatograms is possible by using peak area summation and the presence of an internal standard. The practical quantitation limit for the method is 10 mg/Kg for most fuel types. This paper presents a method for determining the concentration of these fuel types in soil. Data will be presented only on 10W40 lubrication oil in terms of method validation, calibration, percent recovery, and method detection limits. A discussion of the quatitation techniques used will also be included

  5. Expression of MEP Pathway Genes and Non-volatile Sequestration Are Associated with Circadian Rhythm of Dominant Terpenoids Emission in Osmanthus fragrans Lour. Flowers

    Directory of Open Access Journals (Sweden)

    Riru Zheng

    2017-10-01

    Full Text Available Osmanthus fragrans Lour. is one of the top 10 traditional ornamental flowers in China famous for its unique fragrance. Preliminary study proved that the terpenoids including ionone, linalool, and ocimene and their derivatives are the dominant aroma-active compounds that contribute greatly to the scent bouquet. Pollination observation implies the emission of aromatic terpenoids may follow a circadian rhythm. In this study, we investigated the variation of volatile terpenoids and its potential regulators. The results showed that both volatile and non-volatile terpenoids presented circadian oscillation with high emission or accumulation during the day and low emission or accumulation during the night. The volatile terpenoids always increased to reach their maximum values at 12:00 h, while free and glycosylated compounds continued increasing throughout the day. The depletion of non-volatile pool might provide the substrates for volatile emission at 0:00–6:00, suggesting the sequestration of non-volatile compounds acted like a buffer regulating emission of terpenoids. Further detection of MEP pathway genes demonstrated that their expressions increased significantly in parallel with the evident increase of both volatile and non-volatile terpenoids during the day, indicating that the gene expressions were also closely associated with terpenoid formation. Thus, the expression of MEP pathway genes and internal sequestration both played crucial roles in modulating circadian rhythm of terpenoid emission in O. fragrans.

  6. Technology breakthroughs in high performance metal-oxide-semiconductor devices for ultra-high density, low power non-volatile memory applications

    Science.gov (United States)

    Hong, Augustin Jinwoo

    Non-volatile memory devices have attracted much attention because data can be retained without power consumption more than a decade. Therefore, non-volatile memory devices are essential to mobile electronic applications. Among state of the art non-volatile memory devices, NAND flash memory has earned the highest attention because of its ultra-high scalability and therefore its ultra-high storage capacity. However, human desire as well as market competition requires not only larger storage capacity but also lower power consumption for longer battery life time. One way to meet this human desire and extend the benefits of NAND flash memory is finding out new materials for storage layer inside the flash memory, which is called floating gate in the state of the art flash memory device. In this dissertation, we study new materials for the floating gate that can lower down the power consumption and increase the storage capacity at the same time. To this end, we employ various materials such as metal nanodot, metal thin film and graphene incorporating complementary-metal-oxide-semiconductor (CMOS) compatible processes. Experimental results show excellent memory effects at relatively low operating voltages. Detailed physics and analysis on experimental results are discussed. These new materials for data storage can be promising candidates for future non-volatile memory application beyond the state of the art flash technologies.

  7. Analysis of drugs of forensic interest with capillary zone electrophoresis/time-of-flight mass spectrometry based on the use of non-volatile buffers

    Czech Academy of Sciences Publication Activity Database

    Gottardo, R.; Mikšík, Ivan; Aturki, Z.; Sorio, D.; Seri, C.; Fanali, S.; Tagliaro, F.

    2012-01-01

    Roč. 33, č. 4 (2012), s. 599-606 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA203/08/1428 Institutional research plan: CEZ:AV0Z50110509 Keywords : capillary electrophoresis * drugs of abuse * non-volatile buffer * CE-MS Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.261, year: 2012

  8. Calculation of the total plasma concentration of nonvolatile weak acids and the effective dissociation constant of nonvolatile buffers in plasma for use in the strong ion approach to acid-base balance in cats.

    Science.gov (United States)

    McCullough, Sheila M; Constable, Peter D

    2003-08-01

    To determine values for the total concentration of nonvolatile weak acids (Atot) and effective dissociation constant of nonvolatile weak acids (Ka) in plasma of cats. Convenience plasma samples of 5 male and 5 female healthy adult cats. Cats were sedated, and 20 mL of blood was obtained from the jugular vein. Plasma was tonometered at 37 degrees C to systematically vary PCO2 from 8 to 156 mm Hg, thereby altering plasma pH from 6.90 to 7.97. Plasma pH, PCO2, and concentrations of quantitatively important strong cations (Na+, K+, and Ca2+), strong anions (Cl-, lactate), and buffer ions (total protein, albumin, and phosphate) were determined. Strong ion difference was estimated from the measured strong ion concentrations and nonlinear regression used to calculate Atot and Ka from the measured pH and PCO2 and estimated strong ion difference. Mean (+/- SD) values were as follows: Atot = 24.3 +/- 4.6 mmol/L (equivalent to 0.35 mmol/g of protein or 0.76 mmol/g of albumin); Ka = 0.67 +/- 0.40 x 10(-7); and the negative logarithm (base 10) of Ka (pKa) = 7.17. At 37 degrees C, pH of 7.35, and a partial pressure of CO2 (PCO2) of 30 mm Hg, the calculated venous strong ion difference was 30 mEq/L. These results indicate that at a plasma pH of 7.35, a 1 mEq/L decrease in strong ion difference will decrease pH by 0.020, a 1 mm Hg decrease in PCO2 will increase plasma pH by 0.011, and a 1 g/dL decrease in albumin concentration will increase plasma pH by 0.093.

  9. Hip joint injection

    Science.gov (United States)

    ... medicine into the joint. The provider uses a real-time x-ray (fluoroscopy) to see where to place ... Wakefield RJ. Arthrocentesis and injection of joints and soft tissue. In: Firestein GS, Budd RC, Gabriel SE, ...

  10. Premixed direct injection disk

    Science.gov (United States)

    York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin; Zuo, Baifang; Uhm, Jong Ho

    2013-04-23

    A fuel/air mixing disk for use in a fuel/air mixing combustor assembly is provided. The disk includes a first face, a second face, and at least one fuel plenum disposed therebetween. A plurality of fuel/air mixing tubes extend through the pre-mixing disk, each mixing tube including an outer tube wall extending axially along a tube axis and in fluid communication with the at least one fuel plenum. At least a portion of the plurality of fuel/air mixing tubes further includes at least one fuel injection hole have a fuel injection hole diameter extending through said outer tube wall, the fuel injection hole having an injection angle relative to the tube axis. The invention provides good fuel air mixing with low combustion generated NOx and low flow pressure loss translating to a high gas turbine efficiency, that is durable, and resistant to flame holding and flash back.

  11. Imipenem and Cilastatin Injection

    Science.gov (United States)

    Imipenem and cilastatin injection is used to treat certain serious infections that are caused by bacteria, including ... area), gynecological, blood, skin, bone, and joint infections. Imipenem is in a class of medications called carbapenem ...

  12. Quinupristin and Dalfopristin Injection

    Science.gov (United States)

    ... are in a class of medications called streptogramin antibiotics. They work by killing bacteria that cause infections.Antibiotics such as quinupristin and dalfopristin injection will not work for colds, flu, or other viral infections. Taking ...

  13. Botulinum toxin injection - larynx

    Science.gov (United States)

    Injection laryngoplasty; Botox - larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography - guided botulinum toxin treatment; Percutaneous indirect laryngoscopy - guided botulinum toxin treatment; ...

  14. The PEP injection system

    International Nuclear Information System (INIS)

    Brown, K.L.; Avery, R.T.; Peterson, J.M.

    1988-01-01

    A system to transport 10-to-15-GeV electron and positron beams from the Stanford Linear Accelerator and to inject them into the PEP storage ring under a wide variety of lattice configurations has been designed. Optically, the transport line consists of three 360/degree/ phase-shift sections of FODO lattice, with bending magnets interspersed in such a way as to provide achromaticity, convenience in energy and emittance definition, and independent tuning of the various optical parameters for matching into the ring. The last 360/degree/ of phase shift has 88 milliradians of bend in a vertical plane and deposits the beam at the injection septum via a Lambertson magnet. Injection is accomplished by launching the beam with several centimeters of radial betatron amplitude in a fast bump provided by a triad of pulsed kicker magnets. Radiation damping reduces the collective amplitude quickly enough to allow injection at a high repetition rate

  15. Injection and Dump Systems

    CERN Document Server

    Bracco, C; Barnes, M J; Carlier, E; Drosdal, L N; Goddard, B; Kain, V; Meddahi, M; Mertens, V; Uythoven, J

    2012-01-01

    Performance and failures of the LHC injection and ex- traction systems are presented. In particular, a comparison with the 2010 run, lessons learnt during operation with high intensity beams and foreseen upgrades are described. UFOs, vacuum and impedance problems related to the injection and extraction equipment are analysed together with possible improvements and solutions. New implemented features, diagnostics, critical issues of XPOC and IQC applications are addressed.

  16. Bipolar resistive switching in graphene oxide based metal insulator metal structure for non-volatile memory applications

    Science.gov (United States)

    Singh, Rakesh; Kumar, Ravi; Kumar, Anil; Kashyap, Rajesh; Kumar, Mukesh; Kumar, Dinesh

    2018-05-01

    Graphene oxide based devices have attracted much attention recently because of their possible application in next generation electronic devices. In this study, bipolar resistive switching characteristics of graphene oxide based metal insulator metal structure were investigated for nonvolatile memories. The graphene oxide was prepared by the conventional Hummer's method and deposited on ITO coated glass by spin-coating technique. The dominant mechanism of resistive switching is the formation and rupture of the conductive filament inside the graphene oxide. The conduction mechanism for low and high resistance states are dominated by two mechanism the ohmic conduction and space charge limited current (SCLC) mechanism, respectively. Atomic Force Microscopy, X-ray diffraction, Cyclic-Voltammetry were conducted to observe the morphology, structure and behavior of the material. The fabricated device with Al/GO/ITO structure exhibited reliable bipolar resistive switching with set & reset voltage of -2.3 V and 3V respectively.

  17. Density-controllable nonvolatile memory devices having metal nanocrystals through chemical synthesis and assembled by spin-coating technique

    International Nuclear Information System (INIS)

    Wang Guangli; Chen Yubin; Shi Yi; Pu Lin; Pan Lijia; Zhang Rong; Zheng Youdou

    2010-01-01

    A novel two-step method is employed, for the first time, to fabricate nonvolatile memory devices that have metal nanocrystals. First, size-averaged Au nanocrystals are synthesized chemically; second, they are assembled into memory devices by a spin-coating technique at room temperature. This attractive approach makes it possible to tailor the diameter and control the density of nanocrystals individually. In addition, processes at room temperature prevent Au diffusion, which is a main concern for the application of metal nanocrystal-based memory. The experimental results, both the morphology characterization and the electrical measurements, reveal that there is an optimum density of nanocrystal monolayer to balance between long data retention and a large hysteresis memory window. At the same time, density-controllable devices could also feed the preferential emphasis on either memory window or retention time. All these facts confirm the advantages and novelty of our two-step method. (semiconductor devices)

  18. Electrical and ferroelectric properties of RF sputtered PZT/SBN on silicon for non-volatile memory applications

    Science.gov (United States)

    Singh, Prashant; Jha, Rajesh Kumar; Singh, Rajat Kumar; Singh, B. R.

    2018-02-01

    We report the integration of multilayer ferroelectric film deposited by RF magnetron sputtering and explore the electrical characteristics for its application as the gate of ferroelectric field effect transistor for non-volatile memories. PZT (Pb[Zr0.35Ti0.65]O3) and SBN (SrBi2Nb2O9) ferroelectric materials were selected for the stack fabrication due to their large polarization and fatigue free properties respectively. Electrical characterization has been carried out to obtain memory window, leakage current density, PUND and endurance characteristics. Fabricated multilayer ferroelectric film capacitor structure shows large memory window of 17.73 V and leakage current density of the order 10-6 A cm-2 for the voltage sweep of -30 to +30 V. This multilayer gate stack of PZT/SBN shows promising endurance property with no degradation in the remnant polarization for the read/write iteration cycles upto 108.

  19. Nonvolatile memory characteristics influenced by the different crystallization of Ni-Si and Ni-N nanocrystals

    International Nuclear Information System (INIS)

    Chen, W.-R.; Yeh, J.-L.; Chang, C.-Y.; Chang, T.-C.; Chen, S.-C.

    2008-01-01

    The formation of Ni-Si and Ni-N nanocrystals by sputtering a Ni 0.3 Si 0.7 target in argon and nitrogen environment were proposed in this paper. A transmission electron microscope analysis shows the nanocrystals embedded in the nitride layer. X-ray photoelectron spectroscopy and x-ray diffraction also offer the chemical material analysis of nanocrystals with surrounding dielectric and the crystallization of nanocrystals for different thermal annealing treatments. Nonvolatile Ni-Si nanocrystal memories reveal superior electrical characteristics for charge storage capacity and reliability due to the improvement of thermal annealing treatment. In addition, we used energy band diagrams to explain the significance of surrounding dielectric for reliability

  20. Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn; Chi, Li-Feng, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123 (China)

    2015-03-23

    Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process.