Intermolecular Effects on Tunneling through Acenes in Large-Area and Single-Molecule Junctions

Yuru Liu, Luca Ornago, Marco Carlotti, Yong AI, maria el abbasi, Saurabh Soni, Andika Asyuda, Michael Zharnikov, Herre S. J. van der Zant*, Ryan Chiechi*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

2 Citaten (Scopus)
26 Downloads (Pure)

Samenvatting

This paper describes the conductance of single-molecules and self-assembled monolayers comprising an oligophenyleneethynylene core, functionalized with acenes of increasing length that extend conjugation perpendicular to the path of tunneling electrons. In the Mechanically Controlled Break Junction (MCBJ) experiment, multiple conductance plateaus were identified. The high conductance plateau, which we attribute to the single molecule conformation, shows an increase of conductance as a function of acene length, in good agreement with theoretical predictions. The lower plateau is attributed to multiple molecules bridging the junctions with intermolecular interactions playing a role. In junctions comprising a self-assembled monolayer with eutectic Ga–In top-contacts (EGaIn), the pentacene derivative exhibits unusually low conductance, which we ascribe to the inability of these molecules to pack in a monolayer without introducing significant intermolecular contacts. This hypothesis is supported by the MCBJ data and theoretical calculations showing suppressed conductance through the PC films. These results highlight the role of intermolecular effects and junction geometries in the observed fluctuations of conductance values between single-molecule and ensemble junctions, and the importance of studying molecules in both platforms.
Originele taal-2English
Pagina's (van-tot)22776–22783
TijdschriftThe Journal of Physical Chemistry. C: Nanomaterials and Interfaces
Volume124
Nummer van het tijdschrift41
DOI's
StatusPublished - 14-sep-2020

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