Transport in Molecular Junctions with Different Metallic Contacts

TL;DR

This study uses ab initio methods to compare electrical transport properties of phenyl dithiol molecular junctions with different metal contacts, revealing that Pt and Pd form superior contacts compared to Au and Ag.

Contribution

It provides a comparative analysis of charge transfer, electrostatic potential, and conductance in molecular junctions with Au, Ag, Pd, and Pt electrodes using advanced computational techniques.

Findings

Pt has the highest zero-bias conductance.

Pd forms better electrical contacts than Au.

Ag has the lowest conductance among the metals studied.

Abstract

Ab initio calculations of phenyl dithiol connected to Au, Ag, Pd, and Pt electrodes are performed using non-equilibrium Green's functions and density functional theory. For each metal, the properties of the molecular junction are considered both in equilibrium and under bias. In particular, we consider in detail charge transfer, changes in the electrostatic potential, and their subsequent effects on the IV curves through the junctions. Gold is typically used in molecular junctions because it forms strong chemical bonds with sulfur. We find however that Pt and Pd make better electrical contacts than Au. The zero-bias conductance is found to be greatest for Pt, followed by Pd, Au, and then Ag.