Intermolecular effects on tunneling through acenes in large-area and single-molecule junctions

• Verfasst von: Liu, Yuru [VerfasserIn]
• Verfasst von: Ornago, Luca [VerfasserIn]
• Verfasst von: Carlotti, Marco [VerfasserIn]
• Verfasst von: Ai, Yong [VerfasserIn]
• Verfasst von: El Abbassi, Maria [VerfasserIn]
• Verfasst von: Soni, Saurabh [VerfasserIn]
• Verfasst von: Asyuda, Andika [VerfasserIn]
• Verfasst von: Zharnikov, Michael [VerfasserIn]
• Verfasst von: van der Zant, Herre S. J. [VerfasserIn]
• Verfasst von: Chiechi, Ryan C. [VerfasserIn]
• Titel: Intermolecular effects on tunneling through acenes in large-area and single-molecule junctions
• Verf.angabe: Yuru Liu, Luca Ornago, Marco Carlotti, Yong Ai, Maria El Abbassi, Saurabh Soni, Andika Asyuda, Michael Zharnikov, Herre S.J. van der Zant, and Ryan C. Chiechi
• E-Jahr: 2020
• Jahr: September 14, 2020
• Umfang: 8 S.
• Teil: volume:124
• Teil: year:2020
• Teil: number:41
• Teil: pages:22776-22783
• Teil: extent:8
• Fussnoten: Gesehen am 17.06.2021
• Titel Quelle: Enthalten in: The journal of physical chemistry <Washington, DC> / C
• Ort Quelle: Washington, DC : Soc., 2007
• Jahr Quelle: 2020
• Band/Heft Quelle: 124(2020), 41, Seite 22776-22783
• ISSN Quelle: 1932-7455
• DOI: doi:10.1021/acs.jpcc.0c05781
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1760696870

Abstract

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.