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Electronic Transport (electronic + transport)
Selected AbstractsA Multiscale Description of the Electronic Transport within the Hierarchical Architecture of a Composite Electrode for Lithium BatteriesADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Jean-Claude Badot Abstract The broadband dielectric spectroscopy technique is applied, for the first time, to a composite material used as an electrode for lithium battery. The electrical properties (permittivity and conductivity) are measured from low (a few Hz) to microwave (a few GHz) frequencies. The results demonstrate that the broadband dielectric spectroscopy technique is very sensitive to the different scales of the electrode architecture involved in electronic transport, from interatomic distances to macroscopic sizes, as well as to the morphology at these scales, coarse or fine distribution of the constituents. This work opens up new prospects for a more fundamental understanding and more rational optimization of the electronic transport in composite electrodes for lithium batteries and other electrochemical energy storage technologies (including other batteries, supercapacitors, low- and medium-temperature fuel cells), electrochemical sensors and conductor,insulator composite materials. [source] Electronic transport through large quantum dots in the Kondo regimePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003P. Stefa Abstract Conductance through a large two-level quantum dot is investigated theoretically in the strong coupling regime. In large quantum dots the separation between discrete levels becomes smaller than the level width due to strong hybridization with electrodes. In such circumstances, apart from strong electronic correlations in the quantum dot, the indirect interaction between both the spatial levels comes into play. It takes place in lateral quantum dots, where the spatial level index is not conserved during the hybridization process with electrodes. This interaction shifts the Kondo resonance peak in the density of states out of the Fermi surface and alters its intensity. This feature can be observed in the differential conductance dependence vs. bias voltage. The virtual inter-level mixing is suppressed for temperatures above the Kondo temperature of the system. The results of theoretical predictions are compared with the results of experimental conductance measurements performed on large quantum dots and some non-typical conductance features are clarified. [source] Defects and structure of µc-SiOx:H deposited by PECVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3-4 2010Lihong Xiao Abstract Electronic transport and paramagnetic defects detected by Electron Spin Resonance (ESR) in both intrinsic and A Multiscale Description of the Electronic Transport within the Hierarchical Architecture of a Composite Electrode for Lithium BatteriesADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Jean-Claude Badot Abstract The broadband dielectric spectroscopy technique is applied, for the first time, to a composite material used as an electrode for lithium battery. The electrical properties (permittivity and conductivity) are measured from low (a few Hz) to microwave (a few GHz) frequencies. The results demonstrate that the broadband dielectric spectroscopy technique is very sensitive to the different scales of the electrode architecture involved in electronic transport, from interatomic distances to macroscopic sizes, as well as to the morphology at these scales, coarse or fine distribution of the constituents. This work opens up new prospects for a more fundamental understanding and more rational optimization of the electronic transport in composite electrodes for lithium batteries and other electrochemical energy storage technologies (including other batteries, supercapacitors, low- and medium-temperature fuel cells), electrochemical sensors and conductor,insulator composite materials. [source] Organic Electronics: Solution-Grown, Macroscopic Organic Single Crystals Exhibiting Three-Dimensional Anisotropic Charge-Transport Properties (Adv. Mater.ADVANCED MATERIALS, Issue 18 200918/2009) Organic single crystals have the potential to delivering novel electronic devices based on three-dimensional anisotropic electronic transport. The cover shows single crystals of 4-hydroxycyanobenzene (4HCB) grown from solution behind a distorted-perspective partial representation of the crystalline structure hinting at their molecular constituents. The carrier mobility, anisotropic along the three crystallographic axes, is discussed by Fraleoni-Morgera, Fraboni, Femoni, and co-workers on p. 1835. Dr. George Kourousias is acknowledged for the cover design and artwork. [source] Kondo effect in oscillating moleculesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2009Jernej Mravlje Abstract We consider electronic transport through break-junctions bridged by a single molecule in the Kondo regime. We describe the system by a two-channel Anderson model. We take the tunneling matrix elements to depend on the position of the molecule. It is shown, that if the modulation of the tunneling by displacement is large, the potential confining the molecule to the central position between the leads is softened and the position of the molecule is increasingly susceptible to external perturbations that break the inversion symmetry. In this regime, the molecule is attracted to one of the leads and as a consequence the conductance is small. We argue on semi-classical grounds why the softening occurs and corroborate our findings by numerical examples obtained by Wilson's numerical renormalization group and Schönhammer,Gunnarsson's variational method (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Electronic transport measurements in graphene nanoribbonsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2007Melinda Han Abstract We review recent experiments at Columbia on electronic transport in graphene nanostructures. We define the graphene nanostructures by e-beam lithography followed by oxigen plasma etch. In this way we can pattern nanoribbons, rings, as well as other nanostructures. We use this technique to pattern graphene nanoribbons and study the formation of a band gap due to transverse electron confinement. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] How do electrons travel in unusual metallic fluorides of Ag2+?,PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2005Tomasz Jaro Abstract We investigate computationally two representative examples of higher fluorides of Ag(II), namely KAgF3 and AgFBF4. Both compounds formally contain linear (Ag,F)+ chains, in which divalent silver is coordinated additionally by four fluoride anions. For AgFBF4, the equatorial coordination is weak, and leads to metallic conductivity in 1D, as emerges from our band structure calculations. For KAgF3, however, the axial coordination is very strong, and the compound is virtually a 2D metal (i.e. it is mainly the x2,y2 orbitals of Ag that participate in electronic transport in this interesting material). (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Spin-polarized resonant tunneling through two coupled quantum dotsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2006P. Trocha Abstract Resonant electronic transport through two coupled non-interacting single-level quantum dots attached to ferromagnetic leads with collinear magnetizations is analyzed theoretically. Coupling of the dots to external leads as well as the inter-dot coupling are assumed to be spin dependent. Basic transport characteristics, including current-voltage curves, linear and nonlinear conductance, and tunnel magnetoresistance associated with magnetization rotation are calculated using the Green function technique. The relevant Green functions have been calculated by the equation of motion method. Variation of the transport characteristics with such system parameters like energy level position, spin polarization of the leads, and coupling between the dots has been calculated numerically. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]
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