Metal-nanoparticle single-electron transistors fabricated using electromigration

TL;DR

This paper reports the fabrication of metal nanoparticle single-electron transistors with enhanced gate coupling, enabling detailed spectroscopic studies of electron states within the nanoparticles.

Contribution

The authors introduce a novel electromigration-based method to create stable, gate-coupled single-electron transistors from individual metal nanoparticles.

Findings

Achieved access to over ten charge states of gold nanoparticles.

Demonstrated stable devices suitable for spectroscopic analysis.

Enhanced gate coupling compared to previous methods.

Abstract

We have fabricated single-electron transistors from individual metal nanoparticles using a geometry that provides improved coupling between the particle and the gate electrode. This is accomplished by incorporating a nanoparticle into a gap created between two electrodes using electromigration, all on top of an oxidized aluminum gate. We achieve sufficient gate coupling to access more than ten charge states of individual gold nanoparticles (5-15 nm in diameter). The devices are sufficiently stable to permit spectroscopic studies of the electron-in-a-box level spectra within the nanoparticle as its charge state is varied.