The influence of Gaussian strain on sublattice selectivity of impurities in graphene

TL;DR

This paper explores how Gaussian strain applied to graphene can control sublattice selectivity during impurity doping, potentially reducing disorder effects and enabling strain-engineered doping strategies.

Contribution

It introduces a novel method using mechanical strain to induce sublattice asymmetry in graphene doping, combining tight-binding and density functional theory models.

Findings

Strain influences impurity adsorption energies on graphene sublattices.

Localized out-of-plane deformation enhances sublattice selectivity.

Strain parameters can be tuned to control doping processes.

Abstract

Among the different strategies used to induce the opening of a band gap in graphene, one common practice is through chemical doping. While a gap may me opened in this way, disorder-induced scattering is an unwanted side-effect that impacts the electron mobility in the conductive regime of the system. However, this undesirable side effect is known to be minimised if dopants interact asymmetrically with the two sublattices of graphene. In this work we propose that mechanical strain can be used to introduce such a sublattice asymmetry in the doping process of graphene. We argue that a localised out-of-plane deformation applied to a graphene sheet can make one of the graphene sublattices more energetically favourable for impurity adsorption than the other and that this can be controlled by varying the strain parameters. Two complementary modelling schemes are used to describe the electronic structure of the flat and deformed graphene sheets: a tight-binding model and density functional theory. Our results indicate a novel way to select the doping process of graphene through strain engineering.