基于量子干涉效应单分子结电子输运的电化学调控研究

The realization of molecular electronics depends on efficient gating of electron transport at the single-molecule level, which is a hot area and big challenge. Electrochemical method has been received a lot of attentions for its efficiency on gating electron transport of single-molecule. However, only on/off ratio of several tens can be reached, contributing to the current limited study. Meta-benzene based molecules usually exist an unusually destructive quantum interference effect, which would cause a sharp decreasing of conductance depending on the change of energy level in theory. This may solve above problem. This project will investigate the electrochemical gating effect of meta-benzene based molecules by using electrochemical scanning tunneling microscopy break junction. We will also study the influence of anchoring groups and side groups on the electrochemical gating of quantum interference effect. The influence of anchoring groups and side groups on the electrochemical gating of meta-benzene based molecule with quantum interference will be explored by combining theoretical and experimental results. This work can help to deeply understand the gating mechanism of electron transport at single-molecule level, and light the way on development of molecular electronics.

对单分子电子输运进行高效调控是当前的研究热点和巨大挑战，电化学调控作为行之有效的手段受到广泛关注。但由于目前研究局限性，对单分子电子输运电化学只能实现几十倍的调控，不能实现更高效调控。含间位苯基分子电子输运往往具备新奇的破坏性量子干涉现象，理论预测其电导通过适当能级调控，可实现电导几个数量级急剧改变，为高效实现电子输运调控指明方向。本项目将利用申请者发展的低量程扫描隧道显微镜裂结技术，结合电化学方法对含间位苯基量子干涉分子进行电子输运调控，有望获得高开关比的单分子场效应晶体管功能；同时，通过改变不同类型锚定基团的分子电化学调控，研究锚定基团对量子干涉电子输运电化学调控的影响；通过在苯基侧链上加入吸电子和推电子基团，研究侧链基团对其量子干涉电化学调控影响。进一步结合理论计算，揭示含间位苯基量子干涉分子的电子输运调控机理。本研究有助于深入理解单分子的电子输运调控机理，为设计分子器件提供指导。

对单分子电子输运进行高效调控是当前的研究热点和巨大挑战，电化学调控作为行之有效的手段受到广泛关注。但由于研究局限性，对单分子电子输运电化学只能实现几十倍的调控，不能实现更高效调控。含间位苯基分子电子输运往往具备新奇的破坏性量子干涉现象，理论预测其电导通过适当能级调控，可实现电导几个数量级急剧改变，为高效实现电子输运调控指明方向。本项目利用申请者发展的低量程扫描隧道显微镜裂结技术，结合电化学方法对含间位苯基量子干涉分子进行电子输运调控，获得了高开关比(超过2个数量级)的单分子场效应晶体管功能；同时，通过改变不同类型锚定基团的分子电化学调控，研究了锚定基团对量子干涉电子输运电化学调控的影响；通过在苯基侧链上加入吸电子（硝基）和推电子基团（甲氧基），研究了侧链基团对其量子干涉电化学调控影响。进一步结合理论计算，揭示了含间位苯基量子干涉分子的电子输运调控机理。本研究有助于深入理解单分子的电子输运调控机理，为设计分子器件提供指导。