Fabrication of nanometer-spaced electrodes using gold nanoparticles

TL;DR

This paper presents a simple, reproducible method for fabricating nanometer-spaced gold electrodes using colloidal nanoparticles and electromigration, enabling detailed studies of nanoscale electronic transport.

Contribution

The authors introduce a novel technique combining colloidal gold nanoparticles and electromigration to create sub-10 nm gaps in prefabricated electrodes.

Findings

Successfully fabricated sub-10 nm gaps in gold electrodes.

Demonstrated electronic transport measurement on a gold nanoparticle.

Achieved reproducible and scalable electrode fabrication process.

Abstract

A simple and highly reproducible technique is demonstrated for the fabrication of metallic electrodes with nanometer separation. Commercially available bare gold colloidal nanoparticles are first trapped between prefabricated large-separation electrodes to form a low-resistance bridge by an ac electric field. A large dc voltage is then applied to break the bridge via electromigration at room temperature, which consistently produces gaps in the sub-10 nm range. The technique is readily applied to prefabricated electrodes with separation up to 1 micron, which can be defined using optical lithography. The simple fabrication scheme will facilitate electronic transport studies of individual nanostructures made by chemical synthesis. As an example, measurement of a thiol-coated gold nanoparticle showing a clear Coulomb staircase is presented.