Microscopic theory of single-electron tunneling through molecular-assembled metallic nanoparticles

TL;DR

This paper develops a microscopic theory combining electron transport and charging dynamics to analyze single-electron tunneling through metallic nanoparticles connected via molecular bridges, with applications to gold nanoparticles and benzene molecules.

Contribution

It introduces a first-principles based framework for understanding electron tunneling and charging in nanoparticle-molecule systems, integrating molecular junction theory with nanoparticle charging dynamics.

Findings

Calculated background charge and junction capacitance/resistance using NEGF.

Demonstrated tunable transport characteristics through metal-molecule interaction engineering.

Applied theory to gold nanoparticles with benzene-based molecular linkers.

Abstract

We present a microscopic theory of single-electron tunneling through metallic nanoparticles connected to the electrodes through molecular bridges. It combines the theory of electron transport through molecular junctions with the description of the charging dynamics on the nanoparticles. We apply the theory to study single-electron tunneling through a gold nanoparticle connected to the gold electrodes through two representative benzene-based molecules. We calculate the background charge on the nanoparticle induced by the charge transfer between the nanoparticle and linker molecules, the capacitance and resistance of molecular junction using a first-principles based Non-Equilibrium Green's Function theory. We demonstrate the variety of transport characteristics that can be achieved through ``engineering'' of the metal-molecule interaction.