锚原子对碳原子链电子输运性质的影响

Negative Differential Resistance and Rectifying Behaviors in Atomic Molecular Device with Different Anchoring Groups

模拟了两侧包附苯环的碳原子链通过二硫代羧基和硫醇基与金电极(111)面连接组成的分子结的电子输运特性。计算结果表明,锚基团的调制可以改变整个分子器件的电子输运性质。在苯环两侧的锚基团都是二硫代羧基的情况下,在体系电流-电压曲线上发现了新奇的负微分电阻现象;当苯环两侧的锚基团分别为二硫代羧基和硫醇基时,整个体系表现出明显的分子整流效应。

The electronic transport properties of molecular wires made of carbon atomic chains（triynes） capped with benzene are investigated by using nonequilibrium Green′s function in combination with density functional theory.The results show that the anchoring group plays a crucial role in determining the overall conductivity of the molecular junction.Negative differential resistance can be observed when the molecular wire contacts Au electrodes through a dithiocarboxylate linker on both sides,while the rectifying performance is observed when the molecular wire contacts Au electrodes through a thiol linker on one side and with a dithiocarboxylate anchoring group on the other.The mechanisms are suggested for these behaviors.