Transport properties of n-phenyldithiols system anchored on Cu[111] metallic contacts

TL;DR

This study investigates how the number of phenyl rings in n-phenylthiol molecules affects their electronic transport properties when anchored on Cu[111] contacts, revealing that more rings lower the energy gap but reduce conductance.

Contribution

It provides new insights into the relationship between molecular structure and conductance in single-molecule devices using NEGF and DFTB methods.

Findings

Increasing phenyl rings decreases HOMO-LUMO gap.

Conductance decreases with more phenyl rings.

Anchoring broadens and shifts energy levels.

Abstract

Conjugated molecules are materials which are widely studied and developed for molecular electronic technologies focusing on single molecule devices. In this paper we observed the molecular conductance of single molecule based on n phenyl ring systems with linker thiol (Sulfur) anchored on Cu[111] contacts. The non equilibrium Greens function (NEGF) implemented in density functional tight binding (gDFTB) is used to investigate the transport properties. Our result showed that, increase of the phenyl ring will decrease the HOMO LUMO energy gap. However, the conductance is decrease. The energy level of the molecule (isolated molecule) broadens and shifts after anchoring to the Cu[111] contacts.