Ordered Arrays of Gold Nanoparticles Crosslinked by Dithioacetate Linkers for Molecular devices

TL;DR

This study demonstrates that using di-thioacetate terminated molecules to crosslink gold nanoparticles significantly enhances molecular conductance, with experimental and theoretical results showing up to two orders of magnitude improvement, informing better device design.

Contribution

It introduces a novel molecular wiring approach using di-thioacetate linkers in ordered gold nanoparticle arrays, validated by experiments and DFT calculations.

Findings

Conductance increased by up to 100 times with di-thioacetate linkers

Good agreement between experimental and theoretical conductance values

Cooperative effects influence transport efficiency in nanoparticle arrays

Abstract

The final performance of a molecular electronic device is determined by the chemical structure of the molecular wires used in its assembly. Molecular place-exchange was used to incorporate di-thioacetate terminated molecules into ordered arrays of dodecanethiol capped gold nanoparticles. X-ray photoelectron spectroscopy confirmed successful molecular replacement. Room-temperature molecular conductance of a statistically large number of devices reveals that conductance is enhanced by up to two orders of magnitude for the di-thioacetate terminated molecules. Density functional theory transport calculations were performed on five different configurations of the di-thioacetate molecules between gold electrodes, and the calculated average conductance values are in good agreement with the conductance experimentally-observed trend. Our findings highlight important cooperative effects of bridging neighboring gold nanoparticles and choice of appropriate molecular wires when designing devices for efficient transport.