SKM 2023 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 16: Ultrafast Electron Dynamics at Surface and Interfaces II
O 16.8: Talk
Monday, March 27, 2023, 17:00–17:15, TRE Phy
Electronic hybridization and ultrafast dynamics in Terrylene/WS2 heterostructure. — •Samuel Palato1, Boubacar Tanda Bonkano1, Sergey Kovalenko1, Michele Guerrini2, Caterina Cocci2, and Julia Stähler1 — 1Humboldt Universität zu Berlin, DE — 2Carl von Ossietzky Universität Oldenburg, DE
Hybrid organic-inorganic heterostructures offer the possibility of optoelectronic materials with tailored properties. We report on electronic coupling and charge carrier injection in heterostructures formed of terrylene (T) and monolayer WS2 investigated using steady-state and femtosecond optical spectroscopy.
Terrylene molecules in solution show a typical Frank-Condon transition to a singlet state with a lifetime of 3.7 ns. TD-DFT calculations indicate a transition dipole moment along the long axis of the molecule. In contrast, the spectrum of the T film is complex and implies strong H-aggregation. We assign the dynamics to thermal reorganization of the molecules in the film, giving rise to changes in the magnitude and sign of charge-transfer coupling.
The response of the T/WS2 hybrid indicates direct hybridization of higher-lying exciton states. Upon excitation of T/WS2, the transient response is similar to that of WS2; it suggests direct injection of charge carriers from the organic to the inorganic layer.
The presence of hybrid states and the evidence of direct injection underlines the potential of hybrid organic-inorganic materials with tailored optoelectronic properties.