Nanofabrication represents one of the most important features of modern electronics, optoelectronics, photonics and information technologies. However, the ability to fabricate nanoscale (sub-20 nm) devices, requires the introduction of unconventional techniques for material patterning, which is cumbersome, expensive, time consuming, typically available mainly to big industrial companies or to specific research centers, hence, not reachable to the vast majority of research groups and small R&D companies.

Our Solution:
Here we propose a relatively simple approach for the formation of nanoscale devices via catalytic etching of graphene. In this regards, single- or few-layer graphene is used as the electrodes, while their separation (device channel) is defined by a catalytic etching process with a metallic nanostructure. Hence, the nanoscale size of such metallic entity defines the channel length (nanogap) between the graphene-based electrodes.

Nanogap Electrodes:
• The methodologies needed for their preparation are available in most academic and research centers, no need for state-of-the-art nanolithography capability.
• Potential to reach sub -5 nm gaps.
• To be used to characterize nanomaterials in general, inorganic, organic and biological.
• Graphene based electrodes are chemical and thermally stable.
• Potential applications: phase-change material nanodevices and nanogap sensors.

Fig. 1: Schematic representation of the photolithography and patterning of graphene into stripes. Bottom images: MLG and SLG stripe arrays on a SiO2 substrate.

Fig. 2: (a) Schematic representation of the graphene stripe arrays after the catalytic etching and metal particle removal (top) and after metallization of contacts (bottom). (b) Optical image of real devices, the white arrows indicate the location of a ~ 5-micron width single layer graphene stripe. The gold contacts, Au, appear in yellow. (c) Schematic representation of the device in the red square in (b), showing the nanogap formed via the catalytic etching process.