Moura-Moreira Mayra, Felipe Silva Ferreira Denner, Liu Shuanglong, Fry James N, Del Nero Jordan, Cheng Hai-Ping
Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal do Pará, Belém, PA, 66075-110, Brazil.
J Phys Condens Matter. 2019 Nov 6;31(44):445501. doi: 10.1088/1361-648X/ab315a. Epub 2019 Jul 11.
We have investigated electron tunneling through two one-dimensional (1D) molecular junctions based on first-principles simulations using the density functional theory combined with the non-equilibrium Green's functions methodology. The first junction, composed of left and right carbyne wire electrodes with a sodium atom in between, is atomically thin. The second one is quasi-one-dimensional (quasi-1D) and consists of two single-wall carbon nanotube electrodes, closed on the tips and again a sodium atom in the scattering region. Although the bridging atom bonds weakly to the electrodes in both systems, it strongly affects the electronic transport properties, such as electron transmission, current-voltage relation, differential conductance, density of states and eigenchannels. This is demonstrated by comparing with the results obtained from the corresponding systems for both the 1D and the quasi-1D junctions in the absence of the central sodium atom. The revealed transport properties are sensitive to the molecular geometry. This helps future molecular electronic device design.
我们基于密度泛函理论结合非平衡格林函数方法的第一性原理模拟，研究了电子通过两个一维（1D）分子结的隧穿。第一个结由左右碳炔线电极组成，中间夹有一个钠原子，其原子尺度很薄。第二个是准一维（准1D）的，由两个单壁碳纳米管电极组成，尖端封闭，散射区域同样有一个钠原子。尽管在这两个系统中桥接原子与电极的键合较弱，但它强烈影响电子输运性质，如电子传输、电流 - 电压关系、微分电导、态密度和本征通道。通过与在没有中心钠原子的情况下1D和准1D结的相应系统所获得的结果进行比较，证明了这一点。所揭示的输运性质对分子几何结构敏感。这有助于未来分子电子器件的设计。
