权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Transport and transport-related phenomena in gated junctions based on molecules with floppy vibrational degrees of freedom

基于具有松软振动自由度的分子的门控连接中的传输和传输相关现象

基本信息

批准号：
286253420
负责人：
Dr. Ioan Baldea
金额：
--
依托单位：
Department of Chemical Engineering and Materials Science
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/286253420?language=en
关键词：
Transport transport related phenomena gated

项目摘要

Molecular electronics represents a field of great current interest aiming at a deeper understanding of the interplay of chemistry, physics, and engineering at the nanoscale, which should allow to fabricate molecular circuits with desired functionality. Extensive work done in collaboration with the experimental group of Prof. C. D. Frisbie (University of Minnesota) in the first funding period of this project yielded many results providing important insight into transport and transport-related phenomena in nanojunctions based on floppy molecules. Building on those results, this proposal renewal has two objectives. First, stimulated by findings from the first period, we plan further joint theoretical-experimental studies on molecular junctions under mechanical stretching. These studies are strongly motivated by preliminary (unpublished) results revealing a highly puzzling nanoelastic behavior of nanojunctions based on floppy molecules. In view of this completely unusual behavior, we strongly expect that our work will become a new, valuable contribution to nanoelasticiy altogether. Second, in a joint theoretical-experimental effort we aim at investigating for the first time in the literature the charge transport through nanojunctions based on floppy molecules under electrolyte gating using ionic liquids/gels instead of ordinary electrolytes. This experimental approach was recently pioneered by Frisbie's group in organic electronics. The theoretical studies planned in this part differ from the vast majority of existing studies on nanotransport, which assume molecules at frozen geometry. To account for the presence of reorganizable vibrational modes, we will perform ensemble averaging of the transport properties computed at given geometry. The approach to be employed in this project will extend a recent applicant's approach based on a single-step description of nanotransport. That approach, which received recently recognition in the biochemistry and electrochemistry communities, is different from the consensus description based on a two-step mechanism. The ensemble average to be performed is nontrivial because the weight function needed in calculations requires the Gibbs free energy of a junction out of equilibrium and because reorganization related to floppy modes is qualitatively different from that of common solvents. Stronger fluctuation effects due to floppy modes and their temperature (T) dependence are expected in cases where the dominant molecular orbital can be brought closer to electrode Fermi levels. This can be achieved by electrochemical gating, which is the most efficient setup to control energetic alignments. Still, T-ranges accessible using ordinary electrolytes are very limited. Using ionic liquids/gels, a considerably broader T-range can be explored. The theoretical results obtained in this project, to be compared with data emerging from companion experimental studies, will provide new insight into charge transport at the nanoscale.

分子电子学代表了当前非常感兴趣的一个领域，旨在更深入地了解纳米级化学、物理和工程之间的相互作用，这应该允许制造具有所需功能的分子电路。在该项目的第一个资助期，与C.D.Frisbie教授(明尼苏达大学)的实验小组合作所做的广泛工作取得了许多成果，为基于软盘分子的纳米结中的运输和与运输有关的现象提供了重要的见解。在这些结果的基础上，这次提案更新有两个目标。首先，受第一阶段的研究结果的启发，我们计划对机械拉伸下的分子结进行进一步的联合理论-实验研究。这些研究强烈地受到初步(未发表的)结果的推动，这些结果揭示了基于软性分子的纳米结的一种非常令人费解的纳米弹性行为。鉴于这种完全不寻常的行为，我们强烈期待我们的工作将成为对纳米弹性学的新的、有价值的贡献。第二，在理论和实验的联合工作中，我们首次在文献中研究了在电解质门控下，使用离子液体/凝胶而不是普通的电解液，通过基于软性分子的纳米结的电荷传输。这种实验方法最近由Frisbie的有机电子学小组率先提出。这一部分计划的理论研究不同于现有的绝大多数纳米传输研究，后者假设分子处于冻结几何状态。为了解释可重组振动模的存在，我们将对在给定几何条件下计算的输运性质进行系综平均。本项目中采用的方法将扩展最近申请者的方法，该方法基于对纳米传输的一步描述。这种方法最近在生物化学和电化学界得到了认可，不同于基于两步机制的共识描述。所要进行的系综平均不是平凡的，因为计算中所需的权函数需要不平衡的结的吉布斯自由能，而且与软模相关的重组与普通溶剂的重组本质上是不同的。当主导分子轨道更接近电极费米能级时，由于软模及其温度(T)的依赖，有望产生更强的涨落效应。这可以通过电化学门控来实现，这是控制能量排列的最有效的设置。尽管如此，使用普通电解液可以达到的T射程仍然非常有限。使用离子液体/凝胶，可以探索到相当宽的T范围。在这个项目中获得的理论结果，将与来自配套实验研究的数据进行比较，将为研究纳米尺度的电荷传输提供新的见解。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Exceptionally Small Statistical Variations in the Transport Properties of Metal-Molecule-Metal Junctions Composed of 80 Oligophenylene Dithiol Molecules.

DOI：
10.1021/jacs.7b01918
发表时间：
2017-04
期刊：
Journal of the American Chemical Society
影响因子：
15
作者：
Zuoti Xie;I. Bâldea;A. Demissie;Christopher E. Smith;Yanfei Wu;G. Haugstad;C. Frisbie
通讯作者：
Zuoti Xie;I. Bâldea;A. Demissie;Christopher E. Smith;Yanfei Wu;G. Haugstad;C. Frisbie

A surprising way to control the charge transport in molecular electronics: the subtle impact of the coverage of self-assembled monolayers of floppy molecules adsorbed on metallic electrodes.

控制分子电子学中电荷传输的一种令人惊讶的方法：吸附在金属电极上的软盘分子自组装单层覆盖的微妙影响