4,4′-二巯基联苯分子电输运性质的第一性原理研究  

First-principles Calculation of Electronic Transport Properties in Molecular Junction

作　　者：夏蔡娟[1] 房常峰[2,3] 赵鹏[2,3] 

机构地区：[1]西安工程大学理学院,西安710048 [2]山东大学物理学院,济南2501001 [3]山东大学晶体材料国家重点实验室,济南2501001

出　　处：《鲁东大学学报（自然科学版）》2008年第3期227-232,共6页Journal of Ludong University:Natural Science Edition

基　　金：国家自然科学基金(10574082;10474056);山东省自然科学基金(Z2005A01)

摘　　要：以4,4′-二巯基联苯分子为研究对象,利用第一性原理计算方法和非平衡格林函数理论,研究了分子与电极之间连接方式以及电极距离的改变对分子的电子结构和分子电输运性质的影响.计算结果表明,分子与电极之间连接方式以及电极距离的不同会改变分子的几何结构和电子结构,从而影响分子体系的电输运特性,并且发现双硫原子的连接方式比单硫原子的连接方式更加有利于分子电导率的提高,扩展分子的平衡态不是电子输运的最佳状态,适当调节两电极之间的距离可以改善分子的电输运特性.Based on nonequilibrium Green＇s function and first-principles calculations, the electronic transport properties through 4,4＇-biphenyldithiol molecule connected with different anchoring groups （thiol group and dithiocarboxylate group） to gold electrodes, and the effect of different distance between two electrodes with the dithiocarboxylate group connection are investigated. Numerical results show that the dithiocarboxylate anchoring group has a distinct effect on the enhancement of molecular conductance that consistent with the experimental study. The mechanism of conductance enhancement is mainly induced by the molecular orbitals interaction, which produce a new broad transmission peak around the Fermi energy with the dithiocarboxylate group connection. The shortening of the distance between two electrodes results in a stronger coupling and lower potential barrier between them, which leads to a larger conductance.

关 键 词：4 4'-二巯基联苯分子 第一性原理 非平衡格林函数方法 电输运性质 

分 类 号：O494[理学—物理]