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O: Fachverband Oberflächenphysik
O 89: Poster Session VII: Organic molecules on inorganic substrates: electronic, optical and other properties III
O 89.7: Poster
Donnerstag, 4. März 2021, 10:30–12:30, P
Atomic band structure of occupied and unoccupied states of C60 multilayer films — •Ralf Hemm, Florian Haag, Norman Haag, Martin Mitkov, Sebastian Emmerich, Martin Aeschlimann, and Benjamin Stadtmüller — University of Kaiserslautern (TUK) and research center OPTIMAS, Erwin-Schroedinger-Str. 46, 67663 Kaiserslautern, Germany
The implementation of molecular materials in everyday technology is hindered by their poor charge carrier mobility that is rooted in the strong localization of the molecular valence states on single molecular sites. Only in rare cases, strongly dispersive bands have been observed in these materials. Here, we focus on such an exceptional case and study the band structure of C60 multilayers on Ag(111) and Cu(111). Using momentum microscopy, we find strongly dispersive valence bands with complex momentum-dependent photoemission patterns that point to the formation of an atomic crystal-like band structure in C60 thin films [1]. Interestingly, these strongly dispersing states in C60 are not limited to the valence band structure, but also extend to the unoccupied band structure above the vacuum level [2]. These states above the vacuum energy are of particular interest since they are typical final states of the photoemission processes. Hence, their momentum distribution has to be taken into account when extracting the band dispersion of occupied and excited states in a (inverse) photoemission experiment of molecular films on surfaces.
[1] N. Haag et al. Phys. Rev. B 101, 165422 (2020)
[2] J. H. Weaver et al., Phys. Rev. Lett. 66, 1741 (1991)