Adjustment of the work function of pyridine and pyrimidine substituted aromatic self-assembled monolayers by electron irradiation

• Verfasst von: Sauter, Eric [VerfasserIn]
• Verfasst von: Yildirim, Can [VerfasserIn]
• Verfasst von: Terfort, Andreas [VerfasserIn]
• Verfasst von: Zharnikov, Michael [VerfasserIn]
• Titel: Adjustment of the work function of pyridine and pyrimidine substituted aromatic self-assembled monolayers by electron irradiation
• Verf.angabe: Eric Sauter, Can Yildirim, Andreas Terfort, and Michael Zharnikov
• E-Jahr: 2017
• Jahr: May 26, 2017
• Umfang: 8 S.
• Fussnoten: Gesehen am 10.09.2018
• Titel Quelle: Enthalten in: The journal of physical chemistry <Washington, DC> / C
• Ort Quelle: Washington, DC : Soc., 2007
• Jahr Quelle: 2017
• Band/Heft Quelle: 121(2017), 23, Seite 12834-12841
• ISSN Quelle: 1932-7455
• DOI: doi:10.1021/acs.jpcc.7b03302
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 158082241X

Abstract

Self-assembled monolayers (SAMs) are frequently used to manipulate injection barriers in organic electronics by introduction of a specific dipole moment at the interfaces between the electrodes and adjacent organic layers. This is usually achieved by the selection of a proper dipolar terminal tail group comprising the SAM-ambient interface, which was recently complemented by embedding such a group into the molecular backbone. Here we show that the work function of SAMs can also be adjusted by electron irradiation in a quite broad range and in controlled fashion as far as these films contain pyridine or pyrimidine group. This effect is demonstrated by the example of several representative aromatic SAMs with either terminal pyridine group or embedded pyrimidine group. The observed behavior is presumably related to specific chemical transformations involving the nitrogen atoms in these moieties. The SAMs with the embedded pyrimidine group are then especially attractive because this moiety is decoupled from the SAM-ambient interface. The extent of the effect is very large (a work function change of up to ∼0.8 eV) as far as it is monitored in situ but is diminished upon the exposure of the irradiated films to ambient. Practical implications of this effect are discussed, including work function lithography, which is demonstrated by representative patterns.