Molecular ion formation by photoinduced electron transfer at the tetracyanoquinodimethane/Au(111) interface

• Verfasst von: Gerbert, David [VerfasserIn]
• Verfasst von: Tegeder, Petra [VerfasserIn]
• Titel: Molecular ion formation by photoinduced electron transfer at the tetracyanoquinodimethane/Au(111) interface
• Verf.angabe: David Gerbert and Petra Tegeder
• Umfang: 6 S.
• Fussnoten: Gesehen am 07.05.2018
• Titel Quelle: Enthalten in: The journal of physical chemistry letters
• Jahr Quelle: 2017
• Band/Heft Quelle: 8(2017), 19, S. 4685-4690
• ISSN Quelle: 1948-7185
• DOI: doi:10.1021/acs.jpclett.7b01897
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1573993069

Abstract

Optically induced processes in organic materials are essential for light harvesting, switching, and sensor technologies. Here we studied the electronic properties of the tetracyanoquinodimethane(TCNQ)/Au(111) interface by using two-photon photoemission spectroscopy. For this interface we demonstrated the lack of charge-transfer interactions, but we found a significant increase in the sample work function due to UV-light illumination, while the electronic structure of the TCNQ-derived states remain unaffected. Thereby the work function of the interface can be tuned over a wide range via the photon dose. We assigned this to a photoinduced metal-to-molecule electron transfer creating negative ions. The electrons are bound by a small potential barrier. Thus thermal activation reverses the process resulting in the original work function value. The presented photoinduced charge transfer at the TCNQ/Au(111) interface can be used for continuous work function tuning across the substrate’s work function, which can be applied in device-adapted hole-injection layers or organic UV-light sensors.