Le Nam B, Woods Lilia M
Department of Physics, University of South Florida, 4202 E Fowler Ave., Tampa, FL 33620, USA. Institute of Engineering Physics, Hanoi University of Science and Technology, 1 Dai Co Viet, Hanoi 100000, Vietnam.
J Phys Condens Matter. 2016 Sep 14;28(36):364001. doi: 10.1088/0953-8984/28/36/364001. Epub 2016 Jul 8.
Graphene nanoribbons are quasi-one-dimensional planar graphene allotropes with diverse properties dependent on their width and types of edges. Graphene nanoribbons anchored to substrates is a hybrid system, which offers novel opportunities for property modifications as well as experimental control. Here we present electronic structure calculations of zigzag graphene nanoribbons chemically attached via the edges to the Si or C terminated surfaces of a SiC substrate. The results show that the edge characteristics are rather robust and the properties are essentially determined by the individual nanoribbon. While the localized spin polarization of the graphene nanoribbon edge atoms is not significantly affected by the substrate, secondary energy gaps in the highest conduction and lowest valence region may emerge in the anchored structures. The van der Waals interaction together with the electrostatic interactions due to the polarity of the surface bonds are found to be important for the structure parameters and energy stability.
石墨烯纳米带是准一维平面石墨烯同素异形体，其性质多样，取决于其宽度和边缘类型。锚定在基底上的石墨烯纳米带是一种混合体系，它为性质修饰以及实验控制提供了新的机会。在此，我们展示了通过边缘化学连接到SiC基底的Si或C终止表面的锯齿形石墨烯纳米带的电子结构计算。结果表明，边缘特征相当稳定，其性质基本上由单个纳米带决定。虽然石墨烯纳米带边缘原子的局域自旋极化不受基底的显著影响，但在锚定结构中，最高导带和最低价带区域可能会出现二次能隙。发现范德华相互作用以及由于表面键极性引起的静电相互作用对结构参数和能量稳定性很重要。
