Conductance statistics from a large array of sub-10 nm molecular junctions

TL;DR

This study introduces a novel large-scale array of sub-10 nm molecular junctions on gold nanodots, enabling conductance measurement of up to a million junctions simultaneously, revealing conductance peaks and molecular orbital variations.

Contribution

It presents a new fabrication approach for large arrays of molecular junctions and demonstrates high-throughput conductance measurements at an unprecedented scale.

Findings

Two conductance peaks observed for alkylthiol molecules

Tunneling decay constant consistent with previous studies

Molecular orbital energies vary with conductance

Abstract

Devices made of few molecules constitute the miniaturization limit that both inorganic and organic-based electronics aspire to reach. However, integration of millions of molecular junctions with less than 100 molecules each has been a long technological challenge requiring well controlled nanometric electrodes. Here we report molecular junctions fabricated on a large array of sub-10 nm single crystal Au nanodots electrodes, a new approach that allows us to measure the conductance of up to a million of junctions in a single conducting Atomic Force Microscope (C-AFM) image. We observe two peaks of conductance for alkylthiol molecules. Tunneling decay constant (beta) for alkanethiols, is in the same range as previous studies. Energy position of molecular orbitals, obtained by transient voltage spectroscopy, varies from peak to peak, in correlation with conductance values.