Armchair graphene nanoribbons: Electronic structure and electric field modulation

TL;DR

This paper investigates the electronic properties of armchair graphene nanoribbons and how an electric field applied across their width can significantly alter their bandgap, using semi-empirical calculations.

Contribution

It provides detailed electronic structure calculations and explores electric field effects on acGNRs, including bandgap modulation and parameter extraction.

Findings

Electric field can reduce the bandgap to a few meV in semiconducting acGNRs.

Computed important band structure parameters like effective masses and velocities.

Extracted tight-binding parameters for different acGNR types.

Abstract

We report electronic structure and electric field modulation calculations in the width direction for armchair graphene nanoribbons (acGNRs) using a semi-empirical extended Huckel theory. Important band structure parameters are computed, e.g. effectives masses, velocities and bandgaps. For the three types of acGNRs, the pz orbital tight-binding parameters are extracted if feasible. Furthermore, the effect of electric field in the width direction on acGNRs dispersion is explored. It is shown that for the two types of semiconducting acGNRs, an external electric field can reduce the bandgap to a few meV with different quantitative behavior.