On-Surface Synthesis of Graphene Nanoribbons on Two-Dimensional Rare Earth-Gold Intermetallic Compounds

TL;DR

This study presents two methods for synthesizing high-quality armchair-edge graphene nanoribbons on rare earth-gold intermetallic compounds, enabling control over their electronic properties and potential magnetic functionalities.

Contribution

It introduces reliable on-surface synthesis routes for GNRs on TbAu2/Au(111), including direct growth and intercalation, with preserved quality and tunable electronic doping.

Findings

GNRs can be reliably synthesized on TbAu2/Au(111)

Intercalation maintains GNR quality and modifies doping

Band gap remains consistent despite doping changes

Abstract

Here, we demonstrate two reliable routes for the fabrication of armchair-edge graphene nanoribbons (GNRs) on TbAu2/Au(111), belonging to a class of two-dimensional ferromagnetic rare earth-gold intermetallic compounds. On-surface synthesis directly on TbAu2 leads to the formation of GNRs, which are short and interconnected with each other. In contrast, the intercalation approach - on-surface synthesis of GNRs directly on Au(111) followed by rare earth intercalation - yields GNRs on TbAu2/Au(111), where both the ribbons and TbAu2 are of high quality comparable with those directly grown on clean Au(111). Besides, the as-grown ribbons retain the same band gap while changing from p-doping to weak n-doping mainly due to a change in the work function of the substrate after the rare earth intercalation. The intercalation approach might also be employed to fabricate other types of GNRs on various rare earth intermetallic compounds, providing platforms to tailor the electronic and magnetic properties of GNRs on magnetic substrates.