Lithium Mediated Benzene Adsorption on Graphene and Graphene Nanoribbons

TL;DR

This study explores how lithium and benzene molecules interact with graphene and nanoribbons, revealing changes in electronic properties that could enable the development of graphene-based sensors and switches.

Contribution

It provides new insights into lithium and benzene adsorption effects on graphene's electronic structure, highlighting potential applications in sensing and electronic devices.

Findings

High-density lithium adsorption induces metallic and half-metallic states in graphene nanoribbons.

Benzene adsorption on lithium-modified graphene opens a bandgap, tunable by adsorbate density.

Charge transfer dynamics influence the electronic properties, enabling chemical detection.

Abstract

The anchoring of benzene molecules on lithium adsorption sites at the surface of graphene and nanoribbons thereof are investigated. The effects of adsorbate densities, specific adsorption locations, and spin states on the structural stability and electronic properties of the underlying graphene derivatives are revealed. At sufficiently high densities, bare lithium adsorption turns armchair graphene nanoribbons metallic and their zigzag counterparts half-metallic due to charge transfer from the adatom to the {\pi} electronic system. Upon benzene adsorption, the lithium cation encounters two {\pi} systems thus drawing charge back towards the benzene molecule. This, in turn, leads to the opening of a measurable bandgap, whose size and character are sensitive to the adsorbate density, thus indicating that a chemical detector based on lithium adsorbed graphene may be devised. Our results are therefore expected to support the design of novel graphene-based sensing and switching devices.