Dresden 2014 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 46: Low-Dimensional Systems: Molecular Conductors
TT 46.1: Talk
Tuesday, April 1, 2014, 14:00–14:15, HSZ 204
Tuning the hole injection barrier in the intermolecular charge-transfer compound DTBDT-F4TCNQ at metal interfaces — Dennis Bayer1, Sandra Diehl1,2,4, Martin Baumgarten3,4, Klaus Müllen3,4, •Torsten Methfessel1,4, and Hans-Joachim Elmers1,4 — 1Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128 Mainz, Germany — 2Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany — 3Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany — 4SFB/TR49
The codeposition of the organic molecules dithienobenzodithiophene (DTBDT)[1] and tetrafluorotetracyanoquinodimethane (F4TCNQ) on metal surfaces in ultrahigh vacuum leads to the formation of a novel organic charge-transfer (CT) salt. By scanning tunneling spectroscopy at room-temperature we determined the energetic positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals of acceptor (F4TCNQ) and donor (DTBDT) in the pure and in the mixed phase. The mixed phase exhibits a new HOMO close to the Fermi energy depicting a charge-transfer of less than one elementary charge
in agreement with earlier results of the CT-salt TMP-TCNQ[2].
The binding energy of this new orbital varies in dependency on the underlying metal substrate, i.e. 0.4 eV on C(R15×3)/W(110) , 0.25 eV on a monolayer Co/W(110) and 0.16 eV on hcp Co(0001), thus revealing the possibility of tuning the hole injection barrier.
P. Gao et al., Advanced Materials 21, 213 (2009)
K. Medjanik et al., Physical Review B 82, 245419 (2010)