Berlin 2024 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 65: Poster: Molecular Nanostructures on Surfaces
O 65.13: Poster
Mittwoch, 20. März 2024, 18:00–20:00, Poster C
Surface Chemical Bond and Molecular Topology of Polycyclic Aromatic Systems: Pyrene vs. Acepleiadylene — •Lukas Ruppenthal1, Florian Münster1, Neuhaus Leonard1, Tim Naumann1, Jon H. Both1, Jan Herritsch1, Zilin Ruan1, Pengcai Liu2, Xing-Yu Chen2, Jiawen Cao2, Jakob Schramm3, Ralf Tonner-Zech3, Xiao-Ye Wang2, and J. Michael Gottfried1 — 1University of Marburg, Germany — 2Nankai University, China — 3University of Leipzig, Germany
Metal/organic interfaces have a large impact on the performance of organic (opto-)electronic devices. Therefore, the detailed understanding of their chemical, electronic and geometric structure is important for the further technological development. Many common organic semiconductors contain π-electron systems with alternant topologies, whereas non-alternant alternatives have only recently found increasing attention due to their unusual electronic properties. Here, we compare the alternant polycyclic aromatic molecule pyrene with its non-alternant isomer acepleiadylene regarding their interaction with the Cu(111) surface, using PES, NEXAFS, TPD, LT-STM, nc-AFM and DFT. We find that the non-alternant isomer shows increased metal/molecule-interaction and adsorption energy as well as a lower adsorption distance due to its reduced HOMO-LUMO gap, which brings the LUMO energetically closer to the Fermi energy of the metal, causing stronger hybridization with electronic states of the metal surface.
Keywords: Nanographenes; Polycyclic organic hydrocarbons; Scanning probe microscopy; Photoelectron spectroscopy; Surface chemical bond