Download or read book Electron Transport Through Single Molecular Wires written by Sander Jozef Tans and published by . This book was released on 1998 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transport Through Single Molecular Junctions Molecular Wires and Switches written by Veerabhadrarao Kaliginedi and published by . This book was released on 2013 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transport in Molecular Wires with Transition Metal Contacts written by Hugh Dalgleish and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A molecular wire is an organic molecule that forms a conducting bridge between electronic contacts. Single molecules are likely to be the smallest entities to conduct electricity and thus molecular wires present many interesting challenges to fundamental science as well as enormous potential for nanoelectronic technological applications. A particular challenge stems from the realization that the properties of molecular wires are strongly influenced by the Combined characteristics of the molecule and the metal contacts. While gold has been the most studied contact material to date, interest in molecular wires with transition metal contacts that ar e electronically more complex than gold is growing. This thesis presents a theoretical investigation of electron transport and associated phenomena in molecular wires with transition metal contacts. An appropriate methodology is developed on the basis of Landauer theory and Ab initio and semi-empirical considerations and new, physically important systems are identified. Spin-dependent transport mechanisms and device characteristics are explored for molecular wires with ferromagnetic iron contacts, systems that have not been considered previously, either theoretically or experimentally. Electron transport between iron point contacts bridged by iron atoms is also investigated. Spin-dependent transport is also studied for molecules bridging nickel contacts and a possible explanation of some experimentally observed phenomena is proposed. A novel physical phenomenon termed Strong spin current rectification and a new controllable negative differential resistance mechanism with potential applications for molecular electronic technology are introduced. The phenomena predicted in this thesis should be accessible to present day experimental techniques and this work is intended to stimulate experiments directed at observing them.
Download or read book Nanoscience And Technology A Collection Of Reviews From Nature Journals written by Peter Rodgers and published by World Scientific. This book was released on 2009-08-21 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains 35 review articles on nanoscience and nanotechnology that were first published in Nature Nanotechnology, Nature Materials and a number of other Nature journals. The articles are all written by leading authorities in their field and cover a wide range of areas in nanoscience and technology, from basic research (such as single-molecule devices and new materials) through to applications (in, for example, nanomedicine and data storage).
Download or read book Electron Transport in Molecular Wires written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transport in Atomic and Molecular Wires written by Bingqian Xu and published by . This book was released on 2004 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charge and Exciton Transport through Molecular Wires written by Laurens D. A. Siebbeles and published by John Wiley & Sons. This book was released on 2011-07-18 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: As functional elements in opto-electronic devices approach the singlemolecule limit, conducting organic molecular wires are the appropriate interconnects that enable transport of charges and charge-like particles such as excitons within the device. Reproducible syntheses and a thorough understanding of the underlying principles are therefore indispensable for applications like even smaller transistors, molecular machines and light-harvesting materials. Bringing together experiment and theory to enable applications in real-life devices, this handbook and ready reference provides essential information on how to control and direct charge transport. Readers can therefore obtain a balanced view of charge and exciton transport, covering characterization techniques such as spectroscopy and current measurements together with quantitative models. Researchers are thus able to improve the performance of newly developed devices, while an additional overview of synthesis methods highlights ways of producing different organic wires. Written with the following market in mind: chemists, molecular physicists, materials scientists and electrical engineers.
Download or read book Quantum Transport written by Supriyo Datta and published by Cambridge University Press. This book was released on 2005-06-16 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the conceptual framework underlying the atomistic theory of matter, emphasizing those aspects that relate to current flow. This includes some of the most advanced concepts of non-equilibrium quantum statistical mechanics. No prior acquaintance with quantum mechanics is assumed. Chapter 1 provides a description of quantum transport in elementary terms accessible to a beginner. The book then works its way from hydrogen to nanostructures, with extensive coverage of current flow. The final chapter summarizes the equations for quantum transport with illustrative examples showing how conductors evolve from the atomic to the ohmic regime as they get larger. Many numerical examples are used to provide concrete illustrations and the corresponding Matlab codes can be downloaded from the web. Videostreamed lectures, keyed to specific sections of the book, are also available through the web. This book is primarily aimed at senior and graduate students.
Download or read book Single Molecule Electronics written by Manabu Kiguchi and published by Springer. This book was released on 2016-05-23 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a multidisciplinary approach to single-molecule electronics. It includes a complete overview of the field, from the synthesis and design of molecular candidates to the prevalent experimental techniques, complemented by a detailed theoretical description. This all-inclusive strategy provides the reader with the much-needed perspective to fully understand the far-reaching ramifications of single-molecule electronics. In addition, a number of state-of-the-art topics are discussed, including single-molecule spectro-electrical methods, electrochemical DNA sequencing technology, and single-molecule chemical reactions. As a result of this integrative effort, this publication may be used as an introductory textbook to both graduate and advanced undergraduate students, as well as researchers with interests in single-molecule electronics, organic electronics, surface science, and nanoscience.
Download or read book Electron Transport in Molecular Wires microform written by Eldon Emberly and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2000 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transport in Ferrocenes Linked by Molecular Wires written by Yu Li and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field effects on Single Molecular Circuitry written by Albert Cortijos i Aragonès and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Inspired by the proposal that single molecules will be functional elements of future nanoelectronic and Spintronics devices, there exists considerable interest in understanding charge transport in individual molecular backbones. To investigate charge transport in single-molecule devices, in the presented thesis is exploit scanning tunneling microscopy-based approaches in the break-junction mode (STM-BJ) designed by Xu and Tao in 2003 under the effects of magnetic and electric force fields, which divide the thesis in two parts. The first block of the first part of the thesis is presented a study performed at room-temperature based on spin-dependent transport in single-molecule devices employing on thermal spin-crossover metal complexes. Here is shown that the interfacial magnetism or Spinterface, resulting from the interaction between a magnetic molecule and a metal surface, becomes the key pillar to engineer nanoscale molecular devices with novel spin-based functionalities, such as conductance switching based on a Spinfilter, because has the capability to spin-polarize the injected current through it. Also in this block are defined the required conditions which have to be gathered by any molecule to behaves as spin-filtering: be paramagnetic and susceptible to an aligned by external magnetic field, interact with the junction metal electrodes enough strongly through the extended electronic states and also present close energy values to the "fermi energy" for one of the electronic spins allowing its transport. The observed results can be summarized as a high magnetoresistive efficiency of two orders of magnitude (10000%) between the two magnetic field orientations. In the second block of the first part is presented a novel way to form highly conductive and tunable molecular wires exploiting supramolecular chemistry schemes. Single metalloporphyrin rings are wired from its metallic center by using strong Lewis bases, resulting in an increase of the conductivity of three orders of magnitude versus previous single-porphyrin wires. This novel platform of wiring individual porphyrins mimics the way nature exploits these systems by orienting the perpendicular porphyrin axis as the easy axis for electron/energy transfer. Employing this new perpendicular molecule's orientation, spin-depending current measurements were performed following the procedure of the first block using Cu and Co metalloporphyrins. results Spinfilter-switch effect. The observed results can be summarized as a medium magnetoresistive efficiency ca. factor 2-4 between the two magnetic field orientations. The third block of the first part is focused on Spin selectivity induced by electron transport through chiral molecules (CISS) replacing the paramagnetic character of the device's central molecules previously studied. A new method to quantify the spin polarization power of chiral molecules is presented using a junction of either a Dextro- or Levo- 22 amino-acid peptide coupled to an Au surface and to a magnetized Ni contact. As a consequence of the molecular property of helicity filtering and the asymmetry in the density of states at the ferromagnetic electrode, the results show how the conductance can be separated in electron helicity channels where the largest contribution is correlated with the molecular filtering effect in the spin-polarized transport through the chiral peptide. In the second part and based on using external electric fields, is demonstrated the use of the STM-BJ approach to study basic mechanisms in chemical catalysis at the nanoscale. Is designed a surface model system to probe electric field catalysis of a Diels-Alder reaction by delivering an oriented electrical field-stimulus across two reactants: a diene, attached to the STM tip electrode and a dienophile attached to the substrate electrode. This method enables studying chemical reactions at the single-molecule level. Was observed how only an external electric field aligned in the specific way respect to the reaction center and pointing from the diene (bearing a negative charge) to the dienophile (bearing a positive charge) can accelerate the Diels-Alder reaction process. Besides using the external electric field strength as tool was possible to tune the reaction processes." -- TDX.
Download or read book Theoretical Descriptions of Electron Transport Through Single Molecules Developing Design Tools for Molecular Electronic Devices written by Natalie R. Carroll and published by . This book was released on 2004 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduced Density Matrix Approach to the Laser Assisted Electron Transport in Molecular Wires written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The electron transport through a molecular wire under the influence of an external laser field is studied using a reduced density matrix formalism. The full system is partitioned into the relevant part, i.e. the wire, electron reservoirs and a phonon bath. An earlier second-order perturbation theory approach of Meier and Tannor for bosonic environments which employs a numerical decomposition of the spectral density is used to describe the coupling to the phonon bath and is extended to deal with the electron transfer between the reservoirs and the molecular wire. Furthermore, from the resulting time-nonlocal (TNL) scheme a time-local (TL) approach can be determined. Both are employed to propagate the reduced density operator in time for an arbitrary time-dependent system Hamiltonian which incorporates the laser field non-perturbatively. Within the TL formulation, one can extract a current operator for the open quantum system. This enables a more general formulation of the problem which is necessary to employ an optimal control algorithm for open quantum systems in order to compute optimal control fields for time-distributed target states, e.g. current patterns. Thus, we take a fundamental step towards optimal control in molecular electronics. Numerical examples of the population dynamics, laser controlled current, TNL vs. TL and optimal control fields are presented to demonstrate the diverse applicability of the derived formalism.
Download or read book Theoretical Investigations of Molecular Wires written by Julio Leopoldo Palma and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This molecule has two stable conformations (cis and trans) in its electronic ground state, with considerable differences in their conductance. The electron transport properties were calculated using first-principles methods combining non-equilibrium Green's function (NEGF) techniques with density functional theory (DFT). For the azobenzene studies, we included electron-donating groups and electron-withdrawing groups in meta- and ortho- positions with respect to the azo group. The results showed that the molecular structure is crucial in optimizing the electron transport properties of chemical structures, and that the transport properties in electronic devices at the molecular level can be manipulated, enhanced or suppressed by a careful consideration of the effects of chemical modification.
Download or read book Testing Molecular Wires written by Mateusz Wielopolski and published by Springer Science & Business Media. This book was released on 2010-11-02 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a major contribution to the field of charge transport through organic pi-conjugated molecules. Besides its impact on molecular electronics, the work also applies to the design and development of light harvesting, photoconversion and catalytic modules.
Download or read book The Synthesis and Transport Properties of Conjugated Molecular Wires written by Murat Gulcur and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the rapid growth in the electronics industry for over the last century, the demand for more advanced materials has been raised. As a result of this, the number of the scientific studies to develop new type of electronic materials has increased and new fields of research such as molecular electronics and nanotechnology are now established. The trend in the advances in electronics follows the miniaturisation of the electrical components and therefore introducing single or a few molecules into electronic devices has become an important topic. In this work, a summary of the new aspects/developments in the field of single-molecule electronics is presented. Symmetrical tolane compounds with thiol (SH), amino (NH2), pyridyl (Py) and cyano (CN) anchoring groups were synthesised and single-molecule conductances of those molecules were systematically compared. With the help of density functional theory (DFT) calculations, single-molecular junction formation mechanism is also identified. Oligoyne molecular wires with different anchoring groups are also synthesised and their electron transport properties at the single-molecule level are studied. The stability of the functional diaryltetrayne compounds is discussed and X-ray molecular structures of the stable tetraynes are presented. The effects of the molecular length and the anchoring group are discussed in detail. Additionally, oligoynes with methyl shielding of the carbon backbone are synthesised and their stability is discussed. Finally, length-persistent, conjugated OPE and tolane analogues with different molecular lengths and amine anchors were synthesised and their transport properties were investigated in quantum dot sensitised solar cells.
