金属/分子/金属结的电子输运机理与表征

Mechanism and Characterization of Electron Transport Through Metal/Molecule/Metal Junctions

金属/分子/金属结是分子电子学中的基本单元.根据电子的相位是否发生改变,分子结中的电子输运可以分为相干输运和非相干输运两类.在实验上,分子结的表征方法可以分为电学性质表征和非电学性质表征两类.本文借助能级图,首先对分子结的电子输运机理作了简明解释.在此基础上,结合文献报道和本课题组此前的工作,对分子结的一些常用电学表征方法,包括电流-电压特性曲线、电流-时间曲线、电导统计柱状图、转变电压谱、散粒噪声测试、非弹性电子隧道谱和热电效应法进行了介绍.

Although molecular electronics emerged several decades ago, it is still concerning about fundamen- tal issues so far. Metal/molecule/metal junction is a conceptually basic unit in molecular electronics. The mechanism of electron transport through metal/molecule/metal junction has attracted great interest. In general, the mechanisms for electron transport through metal/molecule/metal junctions can be divided into two categories：coherent transport and non-coherent transport according to the phase change of tunneling electrons. In this review, the electron transport mechanism is illustrated briefly by employing energy diagrams. More- over, several extensively measured approaches for studying metal/molecule/metal junctions, including I-V characteristic curve, I-t trace and conductance histogram, transition voltage spectroscopy, shot noise, inelastic electron tunneling spectroscopy, and thermoelectricity are introduced through referring to some recent publica- tions including our works.