book of abstracts - IM2NP

A B S T R A C T S WEDNESDAY, JUNE 30 N A N O S E A 2 0 1 0
9H00-9H20
Valence band photoelectron spectroscopy of the Zn-Phthalocyanine/Ag(110)
interface: Charge transfer and scattering of substrate photoelectrons.
L. Giovanelli 1 , P. Amsalem 2 , T. Angot 3 , L. Petaccia 4 , S. Gorovikov 4 , L.Porte 1 , A.
Goldoni 4 , and J.-M. Themlin 1 (1 IM2NP-CNRS, Aix-Marseille Université, Campus de St. Jérôme,
Marseille, France, 2 Humboldt University, Institut für Physik, Newtonstraße 15, 12489 Berlin, Germany, 3 PIIM-
CNRS, Aix-Marseille Université, Campus de St. Jérôme, Marseille, France, 4 ELETTRA, Sincrotrone Trieste, Area
Science Park, S.S. 14, km 163.5, Basovizza (Trieste), Italy)
The electronic properties of Zn-phthalocyanine vacuum-deposited on Ag(110) are studied by angular
integrated valence band photoelectron spectroscopy. The experiment was performed at the BaD ElPh
beamline at the Elettra synchrotron radiation facility. Sub-monolayer, one ordered monolayer and molecular
layers of increasing thickness present spectral features that can be related to the molecule-substrate
interaction as well as to the effect of the overlayer on the escape conditions of the substrate photoelectrons.
For the first, ordered molecular monolayer, an interface state related to a charge transfer from the substrate to
the molecules is detected through the appearance of a new feature at low binding energy. Such feature is
interpreted as the partial filling of the lowest unoccupied molecular orbital (LUMO). Its lineshape is
addressed in detail and interpreted as a possible hybridization of the LUMO with substrate states as well as
photohole-vibron coupling and correlation effects. Decreasing the temperature down to about 20 K causes an
overal shift to higher binding energies of the interface state. A preliminary explanation is given in terms of
Jahn-Teller distortions. Molecular states lying at higher binding energy show little or negligible modification
as a function of coverage testifying of a weak contribution in the molecule-substrate interaction. Important
changes are found in the spectral region of the Ag 4d bands after the deposition of a sub-monolayer and as a
function of coverage. However, these changes are not interpreted by the formation of new interface states.
Rather, it is shown that these features can be entirely explained by considering the effect of the molecular
overlayer on the escape conditions of the substrate photoelectrons. The effect is the emergence of the
substrate 3D density of states. We argue that such behaviour is expected to apply to other organic adsorbates
over single crystal surfaces.
9H20-9H40
Phthalocyanine induced nanostructuring of the Au(110) surface.
T. Pertram, J. M. Essen, S. Le Moal*, M. Moors, M. Peintinger, C. Becker*, T.
Bredow and K. Wandelt (Institute of Physical and Theoretical Chemistry, University of Bonn,
Wegelerstr.12, D-53115 Bonn, Germany, *CINAM – CNRS – UPR 3118, Aix-Marseille Université, Campus de
Luminy – Case 913, F-13288 Marseille, France)tpertram@uni-bonn.de
The {110} surfaces of fcc metals exhibit an intrinsic anisotropy due to their rectangular surface unit cell.
This anisotropy is even more pronounced in case of the (1x2) missing row reconstruction, which is typical
for the Au(110) surface. We have used this reconstructed surface as a substrate for the ordered (“templated”)
deposition of phthalocyanine molecules.
Phthalocyanines, planar aromatic macrocycles, have attracted considerable attention owing to their
promising application in optical and electronic devices. Especially the adsorption behaviour and film growth
have been investigated in an attempt to offer new nanotechnological and nanoelectronic materials.
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