Angle-dependent bandgap engineering in gated graphene superlattices

TL;DR

This paper investigates how the transmission gap in graphene superlattices varies with the incident angle of electrons, revealing complex angular dependence and tunability from meV to eV, enabling angle-dependent bandgap engineering.

Contribution

It is the first to analyze the angular dependence of the transmission gap in graphene superlattices and demonstrates tunable bandgap engineering through structural parameters.

Findings

Angular dependence of the transmission gap is parabolic at moderate angles.

At large angles, the dependence becomes exponential.

The transmission gap can be tuned from meV to eV by structural modifications.

Abstract

Graphene Superlattices (GSs) have attracted a lot of attention due to its peculiar properties as well as its possible technological implications. Among these characteristics we can mention: the extra Dirac points in the dispersion relation and the highly anisotropic propagation of the charge carriers. However, despite the intense research that is carried out in GSs, so far there is no report about the angular dependence of the Transmission Gap (TG) in GSs. Here, we report the dependence of TG as a function of the angle of the incident Dirac electrons in a rather simple Electrostatic GS (EGS). Our results show that the angular dependence of the TG is intricate, since for moderated angles the dependence is parabolic, while for large angles an exponential dependence is registered. We also find that the TG can be modulated from meV to eV, by changing the structural parameters of the GS. These characteristics open the possibility for an angle-dependent bandgap engineering in graphene.