Understanding the transport characteristics of single molecules bonded between metal electrodes is of fundamental importance for molecular scale electronics. By performing first-principle quantum transport calculations, we investigate the influence of anchoring groups on the conductance of a single molecular junction. The results indicated that the conductance of a single-molecule anchoring the Au electrode with thiol can be enhanced obviously by changing the anchoring group with amine. More importantly, the negative differential resistance behavior is found in the I-V characteristic of this single-molecule junction with thiol anchoring group, which also can be enlarged remarkably by replacing the anchoring group with amine. The results suggest that the diamine as anchoring group has a great potential in molecular electronics.

理解结合在金属电极之间的单分子的传输特性对于分子规模电子学至关重要。通过执行第一性原理量子传输计算，我们研究了锚定基团对单个分子结电导的影响。结果表明，通过改变胺的锚定基团可以明显提高单分子锚定Au电极与巯基的电导率。更重要的是，在具有硫醇锚定基团的单分子结的IV特性中发现了负的差分电阻行为，通过用胺取代锚定基团也可以显着扩大其负IV电阻行为。结果表明，二胺作为锚定基团在分子电子学中具有很大的潜力。