Spectro-microscopy of single and multi-layer graphene supported by a weakly interacting substrate

TL;DR

This study investigates the electronic properties and surface morphology of exfoliated graphene on insulating substrates, revealing that despite microscopic corrugation, the valence band maintains a massless fermionic dispersion, highlighting the importance of substrate interaction control.

Contribution

It provides detailed measurements linking graphene's morphology to its electronic structure, emphasizing substrate interaction effects on electronic properties.

Findings

Graphene exhibits a massless fermionic dispersion with a Fermi velocity of ~10^6 m/s.

Microscopic corrugation does not disrupt the Dirac-like electronic structure.

Controlling substrate interaction is crucial for graphene device performance.

Abstract

We report measurements of the electronic structure and surface morphology of exfoliated graphene on an insulating substrate using angle-resolved photoemission and low energy electron diffraction. Our results show that although exfoliated graphene is microscopically corrugated, the valence band retains a massless fermionic dispersion, with a Fermi velocity of ~10^6 m/s. We observe a close relationship between the morphology and electronic structure, which suggests that controlling the interaction between graphene and the supporting substrate is essential for graphene device applications.