Electronic and Structural Properties of Turbostratic Epitaxial Graphene on the 6H-SiC (000-1) Surface

摘要

We propose an atomistic model to study the interface properties of mis-oriented (turbostratic) epitaxial graphene on the 6H-SiC (000-1) surface. Using calculations from first principles, we compare the energetics and structural/electronic properties of AB and turbostratic stacking sequences within a model based on the Si adatom surface reconstruction. Our calculations show that the systems with AB and turbostratic sequences are very close in energy, demonstrating the possibility of observation of Moire patterns in epitaxial graphene on the C-face of 6H-SiC. The two-dimensional electron gas behavior is preserved in the epitaxial turbostratic graphene systems. However, there are deviations from the ideal turbostratic graphene.