Beyond Single-Molecule Conductance: Understanding and Controlling Charge Transport by External Stimuli and Supramolecular Interactions

该项目由材料研究部（DMR）的电子和光子材料计划（EMT）以及化学结构，动力学和机制计划A和B共同资助（CSDM-A和CSDM-B）。非技术说明：电子学的发展不仅推动了对新的有机和无机（大）分子材料的研究，而且还促进了研究以单分子作为有源元件的电路所需的工具的发展。过去大多数关于创建分子尺度电子器件的研究都集中在分子结构对器件性能的影响上。该项目超越了这些研究，开发了利用分子器件周围环境的方法，以控制和调节电子特性。该项目有助于实现功能分子器件，并扩大实验方法库，以研究和控制单分子水平的电荷传输。活动的一个组成部分包括向初中，高中和本科生介绍跨学科科学，将物理，化学和工程学连接起来，以灌输追求科学事业的愿望。两个PI的实验室是桥接的，因此K-12学校的学生可以在哥伦比亚大学的跨学科研究环境中体验第一手的生活。技术描述：有强烈的需求来理解和使用分子结周围的环境来控制电荷转移特性，并能够创建电路元件的功能分子尺度模拟。大多数过去的研究工作在分子水平上的运输都集中在关联电导的分子结构，而在很大程度上被忽视的交界处周围的直接环境的影响。该项目旨在利用分子环境作为外部刺激来控制和改变单分子器件的电子特性，利用静电，电化学和超分子相互作用。该项目的目标有两个方面：（1）了解环境对分子结传导特性的影响;（2）设计和测量以受控方式响应环境的材料。这个跨学科的研究项目超越了研究分子结的基本组成部分-接触，分子和电极-建立对结与环境之间界面的理解。它使用基于扫描隧道显微镜的断裂结技术来研究大量单分子器件中的溶剂/密封剂效应、氧化还原响应系统和超分子相互作用。

This project is jointly funded by the Electronic and Photonic Materials Program (EPM) in the Division of Materials Research (DMR) and by the Chemical Structure, Dynamics and Mechanisms Programs A and B (CSDM-A and CSDM-B) in the Division of Chemistry (CHE).Nontechnical Description: The drive to miniaturize electronics has not only motivated the search for new organic and inorganic (macro)molecular materials, but has also spurred the development of tools required for studying circuits with single molecules as active elements. Most past research on creating molecular-scale electronic devices has focused on the impact of molecular structure on the device properties. This project goes beyond such studies by developing methods to exploit the environment around molecular devices in order to control and modulate electronic characteristics. The project contributes to the realization of functional molecular devices as well as expansion of an arsenal of experimental methods to study and control charge transport at the single-molecule level. An integral part of the activities include the introduction of interdisciplinary science bridging physics, chemistry and engineering to middle-school, high-school, and undergraduate students, in order to instill a desire to pursue careers in science. Both PIs' laboratories are bridged thus K-12 school students can experience, first-hand, life in interdisciplinary research environment at Columbia University.Technical Description: There is a strong need to understand and use the environment around molecular junctions to control charge transfer characteristics and enable creating functional molecular-scale analogs of circuit elements. Most past research efforts on transport at the molecular level have focused on correlating conductance to molecular structure, while the impact of the immediate environment around the junction has largely been ignored. This project aims to use the molecular environment as an external stimulus to control and alter the electronic characteristics of single-molecule devices, exploiting electrostatic, electrochemical and supramolecular interactions. The goals of this project are two-fold: (1) to understand the effects of the environment on the conduction properties of molecular junctions; and (2) to design and measure materials that respond to the environment in a controlled manner. This interdisciplinary research project goes beyond studying the fundamental components in molecular junctions - contacts, molecules, and electrodes - to establish an understanding of the interface between the junctions and the environment. It uses the scanning tunneling microscope based break-junction technique to study solvent/encapsulant effects, redox responsive systems, and supramolecular interactions in a large number of single-molecule devices.