Interface Structure of Graphene on SiC(000-1)

TL;DR

This paper compares the interface structures of graphene on SiC(000-1) prepared in vacuum versus Si-rich environments, revealing distinct reconstructions and a buffer layer with graphene-like properties.

Contribution

It identifies and characterizes two different interface structures of graphene on SiC(000-1) depending on preparation conditions, including a novel buffer layer structure.

Findings

Vacuum preparation yields a 3x3 reconstructed interface.

Si-rich environment produces a rt(43)xrt(43)-Rb77.6b0 symmetry interface.

Buffer layer with properties similar to known graphene buffer layers.

Abstract

Graphene films prepared by heating the SiC(000-1) surface (the C-face of the {0001} surfaces) in vacuum or in a Si-rich environment are compared. It is found that different interface structures occur for the two situations. The former yields a well known 3x3 reconstructed interface, whereas the latter produces an interface with rt(43)xrt(43)-R\pm7.6 degrees symmetry. This structure is shown to contain a graphene-like layer with properties similar to the 6rt(3)x6rt(3)-R30 degrees "buffer layer" that forms on the Si(0001) surface (the Si-face).