Imaging the interface of epitaxial graphene with silicon carbide via scanning tunneling microscopy

TL;DR

This paper demonstrates the use of scanning tunneling microscopy to image the interface of epitaxial graphene on silicon carbide, revealing transparency at specific energies due to electronic structure, which aids understanding for electronic applications.

Contribution

It introduces a method to image the graphene/SiC interface beneath single layers using STM, supported by DFT calculations explaining the transparency phenomenon.

Findings

STM can image beneath graphene layers at specific energies.

Graphene's transparency at 1 eV is explained by its electronic structure.

The study enhances understanding of graphene/SiC interfaces for electronics.

Abstract

Graphene grown epitaxially on SiC has been proposed as a material for carbon-based electronics. Understanding the interface between graphene and the SiC substrate will be important for future applications. We report the ability to image the interface structure beneath single-layer graphene using scanning tunneling microscopy. Such imaging is possible because the graphene appears transparent at energies of 1 eV above or below the Fermi energy. Our analysis of calculations based on density functional theory shows how this transparency arises from the electronic structure of a graphene layer on a SiC substrate.