Towards scalable nano-engineering of graphene

TL;DR

This paper presents a scalable nano-engineering method for graphene that combines bottom-up self-assembly and top-down nanopatterning, enabling precise control of electronic properties for optical and plasmonic circuits.

Contribution

It introduces a novel approach to pattern graphene at nanometer scale using metal cluster superlattices and STM tip removal, achieving high precision and stability at room temperature.

Findings

Nanopatterned graphene circuits down to 2.5 nm are achievable.

Selective removal of metal clusters is reproducible and stable.

The method allows tuning electronic properties via different materials.

Abstract

By merging bottom-up and top-down strategies we tailor graphene's electronic properties within nanometer accuracy, which opens up the possibility to design optical and plasmonic circuitries at will. In a first step, graphene electronic properties are macroscopically modified exploiting the periodic potential generated by the self assembly of metal cluster superlattices on a graphene/Ir(111) surface. We then demonstrate that individual metal clusters can be selectively removed by a STM tip with perfect reproducibility and that the structures so created are stable even at room temperature. This enables one to nanopattern circuits down to the 2.5 nm only limited by the periodicity of the Moir\'e-pattern, i.e., by the distance between neighbouring clusters, and different electronic and optical properties should prevail in the covered and uncovered regions. The method can be carried out on micro-meter-sized regions with clusters of different materials permitting to tune the strength of the periodic potential.