Tunable Adsorbate-Adsorbate Interactions on Graphene

TL;DR

This paper introduces a method to control adsorbate interactions on graphene by tuning the bonding or chemical potential, based on theoretical and computational models of graphene's electronic effects.

Contribution

It presents a novel mechanism for tuning adsorbate-adsorbate interactions on graphene through electronic mediation, supported by ab initio, tight-binding, and analytical calculations.

Findings

Interaction can be significantly tuned by adjusting bonding or chemical potential.

Two distinct regimes of adsorbate interaction mediated by graphene's pi-electrons.

Theoretical framework applicable to controlling surface chemistry on graphene.

Abstract

We propose a mechanism to control the interaction between adsorbates on graphene. The interaction between a pair of adsorbates---the change in adsorption energy of one adsorbate in the presence of another---is dominated by the interaction mediated by graphene's pi-electrons and has two distinct regimes. Ab initio density functional, numerical tight-binding, and analytical calculations are used to develop the theory. We demonstrate that the interaction can be tuned in a wide range by adjusting the adsorbate-graphene bonding or the chemical potential.