Gao Guanyi, Li Zhongyao, Chen Mingyan, Xie Yiqun, Wang Yin
College of Science, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China.
J Phys Condens Matter. 2017 Nov 1;29(43):435001. doi: 10.1088/1361-648X/aa879f.
Based on the density functional theory method in combination with the nonequilibrium green's function formalism, the quantum transport properties in graphene-[Formula: see text] vertical heterojunction were investigated in this work. The leads are boron doped graphene and seamlessly connect to the graphene nanoribbon in central scattering region. Although there is a weak graphene-[Formula: see text] interaction, molybdenum disulfide can smooth the electrostatic potential and enlarge the transport properties of the whole device. However, another competitive factor is that of the edge states of the [Formula: see text] nanoribbon. When the transport is along the zigzag direction of graphene, the armchair [Formula: see text] nanoribbon simply enlarges the transmission coefficient. Nevertheless, in the armchair transport system, there is an asymmetric electrostatic potential induced by the different atomic potentials of S and Mo atoms at both edges in the zigzag [Formula: see text] nanoribbon, whose potential can lead to obvious scattering from graphene to [Formula: see text] and suppress the transmission probability. Therefore, it also suppresses the influence of zigzag [Formula: see text] nanoribbon on the transmission coefficient. Our first principles simulations provide useful predictions for the application of graphene based emerging electronics, which may stimulate further experimental exploration.
基于密度泛函理论方法并结合非平衡格林函数形式，本文研究了石墨烯-[公式：见原文]垂直异质结中的量子输运性质。引线为硼掺杂石墨烯，并与中心散射区域的石墨烯纳米带无缝连接。尽管存在较弱的石墨烯-[公式：见原文]相互作用，但二硫化钼可以平滑静电势并扩大整个器件的输运性质。然而，另一个竞争因素是[公式：见原文]纳米带的边缘态。当输运沿着石墨烯的锯齿方向时，扶手椅状[公式：见原文]纳米带只是简单地增大了透射系数。然而，在扶手椅状输运系统中，锯齿状[公式：见原文]纳米带两侧的S和Mo原子的不同原子势会诱导出不对称的静电势，其电势会导致从石墨烯到[公式：见原文]的明显散射并抑制透射概率。因此，它也抑制了锯齿状[公式：见原文]纳米带对透射系数的影响。我们的第一性原理模拟为基于石墨烯的新兴电子器件的应用提供了有用的预测，这可能会激发进一步的实验探索。
