The Synthesis and Electrical Transport of Ligand-Protected Au13 Clusters

TL;DR

This paper reports the synthesis of ligand-protected Au13 clusters, their characterization, and electrical transport measurements revealing Coulomb blockade and energy level features, supported by first-principles calculations.

Contribution

It introduces a new synthesis method for Au13 clusters with ligand protection and provides experimental and theoretical insights into their electrical transport properties.

Findings

Size distribution of 0.6 nm observed

Coulomb blockade detected at 1.6 K

Energy gaps of about 60 meV identified

Abstract

The ligand-protected Au13 clusters have been synthesized by using meso-2,3-imercaptosuccinic acid as the reducing and stabilizing agent. Transmission electron microscopic analysis shows a size distribution of 0.6nm. Optical spectrum shows an absorbance peak at 390 nm. The electrical transport measurement devices are fabricated using the electro-migration method. Coulomb blockade is observed at the temperature of 1.6 K,revealing the formation of the tunneling junction. The Coulomb oscillation on-off ratio is nearly 5. Three peaks are extracted in the dI-dV data and attributed to the energy levels of Au13 clusters, gapped by about 60 meV. First principle calculations are carried out to interpret the energy diagram.