CAREER: Electronic and Mechanical Properties of Single Metal-Molecule-Metal Junctions

在这个由化学系实验物理化学项目资助的项目中，哥伦比亚大学的Latha Venkataraman教授将寻求揭示和理解附着在金属电极上的单分子的性质，同时教育学生关于纳米尺度上物理、化学和工程的相互作用。集成电路工业中元件的尺寸正迅速接近纳米级，这就需要对单分子水平上的基本特性有详细的了解。具体来说，这项工作提出了开发和建立一个高分辨率的单轴导电原子力显微镜，以同时测量电子在单个分子结上转移的速率，以及将结分开所需的力。电子特性，如结电阻和电流-电压特性，与本征结特性有关，包括分子长度、构象和分子轨道与金属费米能级的排列。力的测量揭示了键的强度、结合能和结的稳定性，这些特性不能通过电测量直接探测到。这里提出的研究将探索这两个相关但不同的方面的单分子电路。拟议活动的一个组成部分是向高中生、本科生和研究生介绍纳米科学，旨在招募他们从事科学事业。此外，将为大四本科生和研究生开设一门新的纳米技术课程，该课程将整合广泛的主题，从纳米材料的合成到其电荷传输特性以及与电子器件的结合。

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Professor Latha Venkataraman of Columbia University will seek to reveal and understand properties of single molecules attached to metal electrodes while educating students about the interplay of physics, chemistry and engineering at the nanoscale. The size of components in the integrated circuit industry is fast approaching the nanometer scale, requiring a detailed understanding of the fundamental properties at the single molecule level. Specifically, this work proposes to develop and build a high-resolution single-axis conducting atomic force microscope to simultaneously measure the rate at which electrons are transferred across a single molecule junction, as well as the forces required to break the junction apart. Electronic properties, such as junction resistance and current-voltage characteristics, are related to intrinsic junction properties including molecular length, conformation and the alignment of the molecular orbitals with the metal Fermi level. Measurements of forces reveal bond strengths, binding energies and junction stability, properties which cannot be probed directly by electrical measurements. The research proposed here will explore both of these related but different aspects of single-molecule circuits. An integral part of the proposed activity is to introduce nanoscience to high school, undergraduate and graduate students, aiming to recruit them to pursue careers in science. In addition, a new Nanotechnology course for senior undergraduate and graduate students will be developed which will integrate a wide range of topics, from the synthesis of nanoscale materials to their charge transport properties and incorporation into electronic devices.