Gold nanowires and their chemical modifications

TL;DR

This study uses ab-initio simulations to analyze the structure, electronic properties, and conductance of gold nanowires, including effects of chemical modifications like methylthiol adsorption, revealing structural changes and conductance enhancements.

Contribution

It provides new insights into how chemical modifications alter the structure and electronic transport of gold nanowires at the atomic level.

Findings

Dimerization occurs in the bare wire at the imaged geometry.

Adsorption of methylthiol modifies the wire structure.

Chemical modification increases ballistic conductance.

Abstract

Equilibrium structure, local densities of states, and electronic transport in a gold nanowire made of a four-atom chain supported by two gold electrodes, which has been imaged recently by high-resolution electron microscopy, and chemical modification of the wire via the adsorption of a methylthiol molecule, are investigated with ab-initio local density functional simulations. In the bare wire at the imaged geometry the middle two atoms dimerize, and the structure is strongly modified by the adsorption of the molecule with an accompanying increase of the ballistic conductance through the wire.