Wide-Gap Semiconducting Graphene from Nitrogen-Seeded SiC

TL;DR

This paper presents a novel method to produce semiconducting graphene by using surface nitrogen to induce buckling, resulting in a band-gap greater than 0.7 eV, advancing carbon electronics.

Contribution

The study introduces a new nitrogen-seeding technique on SiC that creates a band-gap in graphene by constraining its structure, unlike previous chemical functionalization methods.

Findings

Nitrogen on SiC pins graphene, causing buckling.

Buckled graphene exhibits a band-gap > 0.7 eV.

Method enables semiconducting properties in graphene.

Abstract

All carbon electronics based on graphene has been an elusive goal. For more than a decade, the inability to produce significant band-gaps in this material has prevented the development of semiconducting graphene. While chemical functionalization was thought to be a route to semiconducting graphene, disorder in the chemical adsorbates, leading to low mobilities, have proved to be a hurdle in its production. We demonstrate a new approach to produce semiconducting graphene that uses a small concentration of covalently bonded surface nitrogen, not as a means to functionalize graphene, but instead as a way to constrain and bend graphene. We demonstrate that a submonolayer concentration of nitrogen on SiC is sufficient to pin epitaxial graphene to the SiC interface as it grows, causing the graphene to buckle. The resulting 3-dimensional modulation of the graphene opens a band-gap greater than 0.7eV in the otherwise continuous metallic graphene sheet.