[PDF] Electron Transport Through Single Molecular Junctions Molecular Wires And Switches eBook

Author : Peter Rodgers
Publisher : World Scientific
Page : 367 pages
File Size : 42,78 MB
Release : 2009-08-21
Category : Technology & Engineering
ISBN : 9814466867

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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).

Author : Xuefeng Guo
Publisher : John Wiley & Sons
Page : 408 pages
File Size : 12,85 MB
Release : 2020-07-02
Category : Technology & Engineering
ISBN : 352781888X

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Provides in-depth knowledge on molecular electronics and emphasizes the techniques for designing molecular junctions with controlled functionalities This comprehensive book covers the major advances with the most general applicability in the field of molecular electronic devices. It emphasizes new insights into the development of efficient platform methodologies for building such reliable devices with desired functionalities through the combination of programmed bottom-up self-assembly and sophisticated top-down device fabrication. It also helps to develop an understanding of the device fabrication processes and the characteristics of the resulting electrode-molecule interface. Beginning with an introduction to the subject, Molecular-Scale Electronics: Concept, Fabrication and Applications offers full chapter coverage on topics such as: Metal Electrodes for Molecular Electronics; Carbon Electrodes for Molecular Electronics; Other Electrodes for Molecular Electronics; Novel Phenomena in Single-Molecule Junctions; and Supramolecular Interactions in Single-Molecule Junctions. Other chapters discuss Theoretical Aspects for Electron Transport through Molecular Junctions; Characterization Techniques for Molecular Electronics; and Integrating Molecular Functionalities into Electrical Circuits. The book finishes with a summary of the primary challenges facing the field and offers an outlook at its future. * Summarizes a number of different approaches for forming molecular-scale junctions and discusses various experimental techniques for examining these nanoscale circuits in detail * Gives overview of characterization techniques and theoretical simulations for molecular electronics * Highlights the major contributions and new concepts of integrating molecular functionalities into electrical circuits * Provides a critical discussion of limitations and main challenges that still exist for the development of molecular electronics * Suited for readers studying or doing research in the broad fields of Nano/molecular electronics and other device-related fields Molecular-Scale Electronics is an excellent book for materials scientists, electrochemists, electronics engineers, physical chemists, polymer chemists, and solid-state chemists. It will also benefit physicists, semiconductor physicists, engineering scientists, and surface chemists.

Author : Manabu Kiguchi
Publisher : Springer
Page : 239 pages
File Size : 24,49 MB
Release : 2016-05-23
Category : Science
ISBN : 9811007241

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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.

Author : Juan Carlos Cuevas
Publisher : World Scientific
Page : 724 pages
File Size : 27,12 MB
Release : 2010
Category : Science
ISBN : 9814282588

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This book provides a comprehensive overview of the rapidly developing field of molecular electronics. It focuses on our present understanding of the electrical conduction in single-molecule circuits and provides a thorough introduction to the experimental techniques and theoretical concepts. It will also constitute as the first textbook-like introduction to both the experiment and theory of electronic transport through single atoms and molecules. In this sense, this publication will prove invaluable to both researchers and students interested in the field of nanoelectronics and nanoscience in general. Molecular Electronics is self-contained and unified in its presentation. It may be used as a textbook on nanoelectronics by graduate students and advanced undergraduates studying physics and chemistry. In addition, included are previously unpublished material that will help researchers gain a deeper understanding into the basic concepts involved in the field of molecular electronics.

Author : Laurens D. A. Siebbeles
Publisher : John Wiley & Sons
Page : 293 pages
File Size : 25,25 MB
Release : 2011-07-18
Category : Technology & Engineering
ISBN : 352763309X

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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.

Author : Natalya A. Zimbovskaya
Publisher : Springer
Page : 350 pages
File Size : 44,68 MB
Release : 2013-09-07
Category : Technology & Engineering
ISBN : 1461480116

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A comprehensive overview of the physical mechanisms that control electron transport and the characteristics of metal-molecule-metal (MMM) junctions. As far as possible, methods and formalisms presented elsewhere to analyze electron transport through molecules are avoided. This title introduces basic concepts--a description of the electron transport through molecular junctions—and briefly describes relevant experimental methods. Theoretical methods commonly used to analyze the electron transport through molecules are presented. Various effects that manifest in the electron transport through MMMs, as well as the basics of density-functional theory and its applications to electronic structure calculations in molecules are presented. Nanoelectronic applications of molecular junctions and similar systems are discussed as well. Molecular electronics is a diverse and rapidly growing field. Transport Properties of Molecular Junctions presents an up-to-date survey of the field suitable for researchers and professionals.

Author : Albert Cortijos i Aragonès
Publisher :
Page : 0 pages
File Size : 20,42 MB
Release : 2017
Category :
ISBN :

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"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.

Author : Yong Ai
Publisher :
Page : 0 pages
File Size : 48,97 MB
Release : 2016
Category :
ISBN :

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Molecular electronics has attracted increasing interest in the past decades. Constructing metal/molecules/metal junctions is a basic step towards the investigation of molecular electronics. We have witnessed significant development in both experiment and theory in molecular junctions. This thesis focuses mainly on the study of charge transport through molecular junctions. Conducting polymers and copper filaments were electrochemically deposited with a scanning electrochemical microscope (SECM) configuration between a tip and a substrate electrode. In doing so, we have developed a new way to fabricate atomic contact and molecular junctions, and we have explored the possibility to control, protect and switch these systems.Firstly, SECM, where two microelectrodes are located face-to-face separated by a micrometric gap, has been successfully used for the fabrication of redox-gated conducting polymers junctions, such as PEDOT and PBT. Highly stable and reversible redox-gated nano-junctions were obtained with conductance in the 10-7-10-8 S range in their conducting states. These results, associated with the wire-like growth of the polymer, suggest that the conductance of the entire junction in the conductive state is governed by less than 20 to 100 oligomers.Secondly, to obtain the nano-junctions in a controllable way, a break junction strategy combined with the SECM set up is adopted. A nano-junction could be acquired by pulling the tip away from its initial position. And conductance traces showed that PEDOT junctions can be broken step by step before complete breakdown. Similarly as STM-BJ conductance steps were observed on a PEDOT molecular junction before break down by using SECM-BJ. SECM break junction technique proved to be an efficient way of molecular junction fabrication studies, especially for redox gated polymer molecular junctions. Moreover, a self-terminated strategy is found to be another way to obtain nano-junctions. An external resistance connected to the electrode plays an important role in controlling the size of conducting polymer junctions.PFTQ and PFETQ molecular junctions exhibit well-defined ambipolar transport properties. However, an unbalanced charge transport properties in n- and p- channel for these two polymer junctions was observed when the junctions are in the fiber device scale. In contrast, when molecular junction changes into nano-junction, a balanced n- and p-channel transport property is acquired. We propose that such effect is due to charge transport mechanism changing from diffusive (ohm's law) to ballistic (quantum theory) when the junction size is reduced from fiber devices to nanodevices.High stable Au NPs/ITO electrodes exhibit a well localized surface plasmon (LSP) behavior. These plasmonic substrates have been successfully used to trigger switching of molecular junctions under light irradiation, demonstrating that surface plasmon resonance can induce electrochemical reduction. Such conductance reduction can be attributed to the hot electrons plasmonically generated from gold nanoparticles trapped into the PEDOT junction, resulting in PEDOT being reduced and changed to an insulating state.Finally, copper metallic nanowires were generated using an electrochemical self-terminated method based on SECM configuration. The presence of a few atoms that control the electron transport highlights the formation of metallic nanowires between the asymmetric electrodes. Furthermore, a similar study was performed on mesoporous silica film on ITO used as a substrate electrode. The mesoporous silica films have vertically aligned channels with a diameter of about 3 nm and a thickness of 115 nm, which play a crucial role in protecting the copper filament.