Electron Confinement Induced by Diluted Hydrogen-like Ad-atoms in Graphene Ribbons

TL;DR

This study investigates how diluted hydrogen-like ad-atoms induce electron confinement and localized states in graphene nanoribbons, affecting their transport properties and potential applications in sensors and electronics.

Contribution

It introduces a band-folding model to predict impurity-induced states in graphene nanoribbons with ad-atoms, considering both gapped and randomly doped scenarios.

Findings

Resonant levels and localized states are induced by ad-atoms.

Impurity states are detectable in both gapped and doped graphene.

Transport properties are significantly affected by impurity-induced resonances.

Abstract

We report the electronic properties of two-dimensional systems made of graphene nanoribbons which are patterned with ad-atoms in two separated regions. Due to the extra electronic confinement induced by the presence of the impurities, we find resonant levels, quasi-bound and impurity-induced localized states, which determine the transport properties of the system. Regardless of the ad-atom distribution in the system, we apply band-folding procedures to simple models and predict the energies and the spatial distribution of those impurity-induced states. We take into account two different scenarios: gapped graphene and the presence of randomly distributed ad-atoms in a low dilution regime. In both cases the defect-induced resonances are still detected. Our findings would encourage experimentalist to synthesize these systems and characterize their quasi-localized states employing, for instance, scanning tunneling spectroscopy (STS). Additionally, the resonant transport features could be used in electronic applications and molecular sensor devices.