共查询到20条相似文献，搜索用时 0 毫秒
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Anja Bauer Markus Maier Werner M. Schosser Josefine Diegel Fabian Paschke Yuriy Dedkov Fabian Pauly Rainer F. Winter Mikhail Fonin 《Advanced materials (Deerfield Beach, Fla.)》2020,32(12):1907390
The switching behavior of surface-supported molecular units excited by current, light, or mechanical forces is determined by the shape of the adsorption potential. The ability to tailor the energy landscape in which a molecule resides at a surface gives the possibility of imposing a desired response, which is of paramount importance for the realization of molecular electronic units. Here, by means of scanning tunneling microscopy, a triazatruxene (TAT) molecule on Ag(111) is studied, which shows a switching behavior characterized by transitions of the molecule between three states, and which is attributed to three energetically degenerate bonding configurations. Upon tunneling current injection, the system can be excited and continuously driven, showing a switching directionality close to 100%. Two surface enantiomers of TAT show opposite switching directions pointing at the chirality of the energy landscape of the adsorption potential as a key ingredient for directional switching. Further, it is shown that by tuning the tunneling parameters, the symmetry of the adsorption potential can be controllably adjusted, leading to a suppression of the directionality or an inversion of the switching direction. The findings represent a molecule-surface model system exhibiting unprecedented control of the shape of its adsorption potential. 相似文献
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随着传统硅基电子器件的发展日趋受限,以原子和分子作为电子元器件的研究受到了越来越多的重视.概述了分子电子器件的概念和基本原理,详细介绍了分子导线、分子二极管、分子开关、分子存储器件和分子场效应晶体管的工作原理及最近的研究进展.具有π-共轭结构的有机分子体系是构造分子导线的理想单元;分子结的电子结构不对称性是分子具有整流特性的根本原因;轮烷和索烃是构造分子开关的理想单元之一;分子场效应晶体管的工作原理是量子隧穿,主要是金属-绝缘体-金属间的隧穿效应.最后阐述了目前分子电子器件研究中存在的主要问题. 相似文献
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Grüter L González MT Huber R Calame M Schönenberger C 《Small (Weinheim an der Bergstrasse, Germany)》2005,1(11):1067-1070
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Recent progress in the measurement and modeling of transport in molecular junctions has been very significant. Tunnel transport in the Landauer–Imry regime is now broadly understood for several systems, although a detailed understanding of the role of contact geometry is still required. We overview some clear indications from recent research and note the quite reasonable agreement between measured and calculated conductance in metal–molecule–metal junctions. The next challenge lies in obtaining a microscopic understanding of charge transport that involves reduction or oxidation of molecules. 相似文献
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D.‐H. Qu F.‐Y. Ji Q.‐C. Wang H. Tian 《Advanced materials (Deerfield Beach, Fla.)》2006,18(15):2035-2038
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Velimir Meded Alexei Bagrets Andreas Arnold Ferdinand Evers 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(19):2218-2223
Recent experiments have shown that the current–voltage characteristics (I–V) of BPDN‐DT (bipyridyl‐dinitro oligophenylene‐ethynylene dithiol) can be switched in a very controlled manner between “on” and “off” traces by applying a pulse in a bias voltage, Vbias. Here, the polaron formation energies are calculated to check a frequently held belief, namely, that the polaron formation can explain the observed bistability. These results are not consistent with such a mechanism. Instead, a conformational reorientation is proposed. The molecule carries an intrinsic dipole moment, which couples to Vbias. Ramping Vbias exerts a force on the dipole that can reorient (“rotate”) the molecule from the ground state (“off”) into a metastable configuration (“on”) and back. By elaborated electronic structure calculations, a specific path for this rotation is identified through the molecule's conformational phase space. It is shown that this path has sufficiently high barriers to inhibit thermal instability but that the molecule can still be switched in the voltage range of the junction stability. The theoretical I–Vs qualitatively reproduce the key experimental observations. A proposal for the experimental verification of the alternative mechanism of conductance switching is presented. 相似文献
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Jose Muñoz; 《Advanced materials (Deerfield Beach, Fla.)》2024,36(8):2305546
The ability of electronic devices to act as switches makes digital information processing possible. Succeeding graphene, emerging inorganic 2D materials (i2DMs) have been identified as alternative 2D materials to harbor a variety of active molecular components to move the current silicon-based semiconductor technology forward to a post-Moore era focused on molecule-based information processing components. In this regard, i2DMs benefits are not only for their prominent physiochemical properties (e.g., the existence of bandgap), but also for their high surface-to-volume ratio rich in reactive sites. Nonetheless, since this field is still in an early stage, having knowledge of both i) the different strategies for molecularly functionalizing the current library of i2DMs, and ii) the different types of active molecular components is a sine qua non condition for a rational design of stimuli-responsive i2DMs capable of performing logical operations at the molecular level. Consequently, this Review provides a comprehensive tutorial for covalently anchoring ad hoc molecular components—as active units triggered by different external inputs—onto pivotal i2DMs to assess their role in the expanding field of molecule-programmable nanoelectronics for electrically monitoring bistable molecular switches. Limitations, challenges, and future perspectives of this emerging field which crosses materials chemistry with computation are critically discussed. 相似文献
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Carleen M. Bowers Minlu Zhang Yekaterina Lyubarskaya Eric J. Toone Ching Tang Alexander A. Shestopalov 《Advanced Materials Interfaces》2014,1(2)
This study uses a novel surface engineering approach to demonstrate the influence of organic functional group substitutions on molecular electronic properties. Specifically, bilayered organic monomolecular systems immobilized on an inorganic electrode as the charge‐injecting components of organic electronic devices are compared. Recent literature reports demonstrate that structural modification in functional monolayers have unpredictable effects on their electronic properties. These studies indicate that the structure most certainly plays an important role, but its effect on the molecular resistance is diminished due to differences in other monolayer parameters. It is demonstrated that a separate control over the monolayer geometry and its chemical structure is required in order to observe predictable structure‐property relations. Here, bilayered molecular interfaces, comprising inert and functional layers whose properties can be independently controlled, are formed. It is shown that 1) the charge transfer through the bilayered system is sensitive to small structural molecular changes; 2) that it can be controlled and predicted by controlling the electron‐withdrawing or donating nature of the organic moiety; and 3) that the differences in the charge transfer dynamics of two bilayered systems can be visualized via patterned electroluminescence. 相似文献
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U. Schrter E. Scheer R. Arnold C. Bacca T. Bhler J. Grebing P. Konrad V. Kunej N. Kang H.‐F. Pernau C. Schirm 《Advanced Engineering Materials》2005,7(9):795-803
Electrical contacts of the width of only one atom can be realized by the break‐junction technique. The conductance decreases stepwise due to structural reconfigurations when tearing a nano‐bridge in the few‐atom range. Transport is described by an ensemble of channels with possibly quite high transmission probabilities. For a single break‐junction the last one‐atom contact consists of a material‐specific channel ensemble, determined by the chemical valance as verified for quite a number of metals. d‐electrons in half‐metals and spin‐effects in magnetic materials will complicate this simple model. Break‐junctions also provide ideal contacts to investigate transport through freely suspended clusters or molecules like DNA. 相似文献
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Molecular Electronics: Noncovalent Self‐Assembled Monolayers on Graphene as a Highly Stable Platform for Molecular Tunnel Junctions (Adv. Mater. 4/2016) 
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下载免费PDF全文 Peng Song C. S. Suchand Sangeeth Damien Thompson Wei Du Kian Ping Loh Christian A. Nijhuis 《Advanced materials (Deerfield Beach, Fla.)》2016,28(4):784-784
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David A. Egger Ferdinand Rissner Egbert Zojer Georg Heimel 《Advanced materials (Deerfield Beach, Fla.)》2012,24(32):4403-4407
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Dong Xiang Hyunhak Jeong Takhee Lee Dirk Mayer 《Advanced materials (Deerfield Beach, Fla.)》2013,25(35):4845-4867
A mechanically controllable break junction (MCBJ) represents a fundamental technique for the investigation of molecular electronic junctions, especially for the study of the electronic properties of single molecules. With unique advantages, the MCBJ technique has provided substantial insight into charge transport processes in molecules. In this review, the techniques for sample fabrication, operation and the various applications of MCBJs are introduced and the history, challenges and future of MCBJs are discussed. 相似文献