Fabrication of hybrid molecular devices using multi-layer graphene break junctions

TL;DR

This paper presents a method for fabricating hybrid molecular devices using patterned multilayer graphene break junctions, enabling precise localization of nanogaps for molecular integration with potential applications in spintronics and molecular circuits.

Contribution

The study introduces a novel fabrication technique combining helium ion microscopy and electroburning to create controlled nanogaps in multilayer graphene for molecular device integration.

Findings

Controlled nanogap formation via electroburning in patterned graphene.

Ability to integrate single molecules with superconducting contacts.

Potential extension to spintronic devices with ferromagnetic contacts.

Abstract

We report on the fabrication of hybrid molecular devices employing multilayer graphene (MLG) flakes which are patterned with a constriction using a helium ion microscope (HIM) or an oxygen plasma etch. The patterning step allows for the localization of a few-nanometer gap, created by electroburning, that can host single molecules or molecular ensembles. By controlling the width of the sculpted constriction, we regulate the critical power at which the electroburning process begins. We estimate the flake temperature given the critical power and find that at low powers it is possible to electroburn MLG with superconducting contacts in close proximity. Finally, we demonstrate the fabrication of hybrid devices with superconducting contacts and anthracene-functionalized copper curcuminoid molecules. This method is extendable to spintronic devices with ferromagnetic contacts and a first step towards molecular integrated circuits.