Optimizing Electronic Structure and Quantum Transport at the Graphene-Si(111) Interface: An Ab Initio Density-Functional Study

Ceren Tayran, Zhen Zhu, Matteo Baldoni, Daniele Selli, Gotthard Seifert, and David Tománek

Phys. Rev. Lett. 110, 176805 – Published 26 April 2013

Abstract

We use ab initio density-functional calculations to determine the interaction of a graphene monolayer with the Si(111) surface. We find that graphene forms strong bonds to the bare substrate and accommodates the 12% lattice mismatch by forming a wavy structure consisting of free-standing conductive ridges that are connected by ribbon-shaped regions of graphene, which bond covalently to the substrate. We perform quantum transport calculations for different geometries to study changes in the transport properties of graphene introduced by the wavy structure and bonding to the Si substrate. Our results suggest that wavy graphene combines high mobility along the ridges with efficient carrier injection into Si in the contact regions.

Received 15 January 2013

DOI:https://doi.org/10.1103/PhysRevLett.110.176805

Authors & Affiliations

Ceren Tayran^1,2, Zhen Zhu¹, Matteo Baldoni³, Daniele Selli³, Gotthard Seifert³, and David Tománek^1,*

¹Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA
²Department of Physics, Gazi University, Teknikokullar, 06500 Ankara, Turkey
³Physikalische Chemie, Technische Universität Dresden, D-01062 Dresden, Germany