Metal to insulator transition in epitaxial graphene induced by molecular doping

TL;DR

This study demonstrates a reversible metal-insulator transition in epitaxial graphene achieved through molecular doping, enabling precise control of charge carriers and opening new avenues for electronic applications and fundamental studies.

Contribution

It introduces a method to reversibly tune charge carriers in epitaxial graphene from electrons to holes using molecular doping, verified by ARPES measurements.

Findings

Reversible metal-insulator transition observed in epitaxial graphene.

Precise control of charge carrier type and density achieved.

Insights into electron screening and disorder effects.

Abstract

The capability to control the type and amount of charge carriers in a material and, in the extreme case, the transition from metal to insulator is one of the key challenges of modern electronics. By employing angle resolved photoemission spectroscopy (ARPES) we find that a reversible metal to insulator transition and a fine tuning of the charge carriers from electrons to holes can be achieved in epitaxial bilayer and single layer graphene by molecular doping. The effects of electron screening and disorder are also discussed. These results demonstrate that epitaxial graphene is suitable for electronics applications, as well as provide new opportunities for studying the hole doping regime of the Dirac cone in graphene.