title: Mode-selective vibrational modulation of charge transport in organic electronic devices.
abstract: The soft character of organic materials leads to strong coupling between molecular, nuclear and electronic dynamics. This coupling opens the way to influence charge transport in organic electronic devices by exciting molecular vibrational motions. However, despite encouraging theoretical predictions, experimental realization of such approach has remained elusive. Here we demonstrate experimentally that photoconductivity in a model organic optoelectronic device can be modulated by the selective excitation of molecular vibrations. Using an ultrafast infrared laser source to create a coherent superposition of vibrational motions in a pentacene/C60 photoresistor, we observe that excitation of certain modes in the 1,500-1,700 cm(-1) region leads to photocurrent enhancement. Excited vibrations affect predominantly trapped carriers. The effect depends on the nature of the vibration and its mode-specific character can be well described by the vibrational modulation of intermolecular electronic couplings. This presents a new tool for studying electron-phonon coupling and charge dynamics in (bio)molecular materials.
authors.affiliation: 1] FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands [2] Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3OHE, UK.
authors.forename: Artem A
authors.initials: AA
authors.lastname: Bakulin
authors.affiliation: 1] Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel [2].
authors.forename: Robert
authors.initials: R
authors.lastname: Lovrincic
authors.affiliation: Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Xi
authors.initials: X
authors.lastname: Yu
authors.affiliation: FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Oleg
authors.initials: O
authors.lastname: Selig
authors.affiliation: FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Huib J
authors.initials: HJ
authors.lastname: Bakker
authors.affiliation: FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Yves L A
authors.initials: YL
authors.lastname: Rezus
authors.affiliation: Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Pabitra K
authors.initials: PK
authors.lastname: Nayak
authors.affiliation: School of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, USA.
authors.forename: Alexandr
authors.initials: A
authors.lastname: Fonari
authors.affiliation: School of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, USA.
authors.forename: Veaceslav
authors.initials: V
authors.lastname: Coropceanu
authors.affiliation: Solar &Photovoltaics Engineering Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Brédas
authors.affiliation: Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Cahen