Institut für Physikalische Chemie, Technische Universität Dresden, D-01062 Dresden, Germany.
J Phys Condens Matter. 2013 Oct 30;25(43):435302. doi: 10.1088/0953-8984/25/43/435302. Epub 2013 Oct 4.
We investigate the interaction of a graphene monolayer with the C(111) diamond surface using ab initio density functional theory. To accommodate the lattice mismatch between graphene and diamond, the overlayer deforms into a wavy structure that binds strongly to the diamond substrate. The detached ridges of the wavy graphene overlayer behave electronically as free-standing polyacetylene chains with delocalized π electrons, separated by regions containing only sp(3) carbon atoms covalently bonded to the (111) diamond surface. We performed quantum transport calculations for different geometries of the system to study how the buckling of the graphene layer and the associated bonding to the diamond substrate affect the transport properties. The system displays high carrier mobility along the ridges and a wide transport gap in the direction normal to the ridges. These intriguing, strongly anisotropic transport properties qualify the hybrid graphene-diamond system as a viable candidate for electronic nanodevices.
我们使用第一性原理密度泛函理论研究了单层石墨烯与 C(111) 金刚石表面的相互作用。为了适应石墨烯和金刚石之间的晶格失配，覆盖层变形为波状结构，与金刚石基底强烈结合。波状石墨烯覆盖层的分离脊在电子上表现为独立的聚乙炔链，具有离域的π电子，由仅包含 sp(3) 碳原子的区域隔开，这些碳原子通过共价键与（111）金刚石表面结合。我们针对不同的系统几何形状进行了量子输运计算，以研究石墨烯层的弯曲和与金刚石基底的相关结合如何影响输运性质。该系统在脊的方向表现出沿脊的高载流子迁移率和宽的输运间隙。这些引人入胜的、强烈各向异性的输运性质使混合石墨烯-金刚石系统成为电子纳米器件的可行候选者。
