SurfaceScience21 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 79: Poster Session VI: Ultrafast electron dynamics at surface and interfaces II
O 79.3: Poster
Mittwoch, 3. März 2021, 13:30–15:30, P
Transient band structure renormalizations and ultrafast exciton dynamics in fullerene thin films — •Sebastian Hedwig, Sebastian Emmerich, Benito Arnoldi, Johannes Stöckl, Benjamin Stadtmüller, and Martin Aeschlimann — Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schrödinger-Straße 46, 67663 Kaiserslautern, Germany
Fullerenes have been subject to intense research in the past decades, with promising potential for their implementation in optoelectronic devices. Resonant optical excitation of a fullerene thin film leads to a transient renormalization of the polaronic valence band structure which follows the timescale of CT-exciton formation and decay, as recently shown for C60 [1,2]. Embedding metal atoms or clusters into the carbon cage can alter the cage symmetry and density of states leading to new relaxation channels, such as the cluster-cage electron transfer. Here, we present time resolved fs UV-pump XUV-probe photoemission studies carried out on thin films of C60 and the endohedral metallofullerene Sc3N@C80. Both fullerene complexes reveal almost identical band structure changes upon optical excitation evolving on similar timescales. For Sc3N@C80, we also show that the exciton and polaron dynamics are strongly altered upon K intercalation of the pristine film. This enables us to reveal the role of the cluster-cage charge transfer on the ultrafast carrier dynamics in fullerene thin films [3].
[1] B. Stadtmüller et al., Nat Commun 10, 1470 (2019)
[2] S. Emmerich et al., J. Phys. Chem. C 124, 23579-23587 (2020)
[3] S. Emmerich et al., arXiv:2002.04576 (2020)