Huang Zhifeng, Chen Fang, D'agosta Roberto, Bennett Peter A, Di Ventra Massimiliano, Tao Nongjian
Nat Nanotechnol. 2007 Nov;2(11):698-703. doi: 10.1038/nnano.2007.345. Epub 2007 Oct 28.
A basic aim in molecular electronics is to understand transport through a single molecule connected to two electrodes. Substantial progress towards this goal has been made over the past decade as a result of advances in both experimental techniques and theoretical methods. Nonetheless, a fundamental and technologically important issue, current-induced local heating of molecules, has received much less attention. Here, we report on a combined experimental and theoretical study of local heating in single molecules (6-, 8- and 10-alkanedithiol) covalently attached to two gold electrodes as a function of applied bias and molecular length. We find that the effective local temperature of the molecular junction first increases with applied bias, and then decreases after reaching a maximum. At fixed bias, the effective temperature decreases with increasing molecular length. These experimental findings are in agreement with hydrodynamic predictions, which include both electron-phonon and electron-electron interactions.
分子电子学的一个基本目标是理解通过连接到两个电极的单个分子的输运过程。由于实验技术和理论方法的进步，在过去十年里朝着这个目标取得了重大进展。然而，一个基本且在技术上很重要的问题，即电流诱导的分子局部加热，受到的关注要少得多。在这里，我们报告了一项关于共价连接到两个金电极上的单分子（6 -、8 - 和 10 - 链烷二硫醇）局部加热的实验与理论相结合的研究，该研究考察了局部加热与外加偏压和分子长度的关系。我们发现分子结的有效局部温度首先随外加偏压升高，在达到最大值后下降。在固定偏压下，有效温度随分子长度增加而降低。这些实验结果与流体动力学预测相符，流体动力学预测中同时考虑了电子 - 声子和电子 - 电子相互作用。
