Journal Article

FZJ-2022-02096

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Hexacene on Cu(110) and Ag(110): Influence of the Substrate on Molecular Orientation and Interfacial Charge Transfer

Sättele, M. S. ; Windischbacher, A. ; Greulich, K. ; Egger, L. ; Haags, A. (Corresponding author)FZJ* ; Kirschner, H. ; Ovsyannikov, R. ; Giangrisostomi, E. ; Gottwald, A. ; Richter, M. ; Soubatch, S.FZJ* ; Tautz, F. S.FZJ* ; Ramsey, M. G. ; Puschnig, P. ; Koller, G. ; Bettinger, H. F. ; Chassé, T. ; Peisert, H. (Corresponding author)

2022
Soc. Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/31132  doi:10.1021/acs.jpcc.2c00081

Abstract: Hexacene, composed of six linearly fused benzene rings, is an organic semiconductor material with superior electronic properties. The fundamental understanding of the electronic and chemical properties is prerequisite to any possible application in devices. We investigate the orientation and interface properties of highly ordered hexacene monolayers on Ag(110) and Cu(110) with X-ray photoemission spectroscopy (XPS), photoemission orbital tomography (POT), X-ray absorption spectroscopy (XAS), low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), and density functional theory (DFT). We find pronounced differences in the structural arrangement of the molecules and the electronic properties at the metal/organic interfaces for the two substrates. While on Cu(110) the molecules adsorb with their long molecular axis parallel to the high symmetry substrate direction, on Ag(110), hexacene adsorbs in an azimuthally slightly rotated geometry with respect to the metal rows of the substrate. In both cases, molecular planes are oriented parallel to the substrate. A pronounced charge transfer from both substrates to different molecular states affects the effective charge of different C atoms of the molecule. Through analysis of experimental and theoretical data, we found out that on Ag(110) the LUMO of the molecule is occupied through charge transfer from the metal, whereas on Cu(110) even the LUMO+1 receives a charge. Interface dipoles are determined to a large extent by the push-back effect, which are also found to differ significantly between 6A/Ag(110) and 6A/Cu(110).

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Contributing Institute(s):

1. Quantum Nanoscience (PGI-3)

Research Program(s):

1. 5213 - Quantum Nanoscience (POF4-521) (POF4-521)

Appears in the scientific report 2022

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Science Citation Index Expanded ; Web of Science Core Collection

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