Scanning Tunneling Microscopy and Spectroscopy of Graphene on Insulating Substrates

TL;DR

This paper reviews scanning tunneling microscopy and spectroscopy studies on monolayer graphene on insulating substrates, highlighting morphology, nanomechanical manipulation, and electronic interactions relevant for device applications.

Contribution

It provides a comprehensive overview of STM/STS techniques applied to graphene on insulators, emphasizing recent experimental findings and their implications for graphene electronics.

Findings

Graphene morphology varies on different insulating substrates.

STM can manipulate graphene at the nanoscale.

Spectroscopy reveals electron-disorder interactions in graphene.

Abstract

Graphene is a truly two-dimensional material with exceptional electronic, mechanical, and optical properties. As such, it consists of surface only and can be probed by the well developed surface-science techniques as, e.g., scanning tunneling microscopy. This method bridges the gap between the surface science community and the electronic device community and might lead to novel combined approaches. Here, I review some of the scanning tunneling microscopy (STM) and spectroscopy (STS) experiments on monolayer graphene samples. I will concentrate on graphene samples deposited on insulating substrates, since these are related to graphene device concepts. In particular, I will discuss the morphology of graphene on SiO$_2$ and other emerging substrates, some nanomechanical manipulation experiments using STM, and spectroscopic results. The latter can map the disorder potentials as well as the interaction of the electrons with the disorder which is most pronounced in the quantum Hall regime.