Regensburg 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 9: Ultrafast Electron Dynamics at Surfaces and Interfaces 2
O 9.12: Talk
Monday, September 5, 2022, 17:45–18:00, H3
Spin and charge carrier dynamics at a CuPc/WSe2 heterostructure — •Sebastian Hedwig1, Gregor Zinke1, Benito Arnoldi1, Martin Aeschlimann1, and Benjamin Stadtmüller1,2 — 1Department of Physics and Research Center OPTIMAS, TU Kaiserslautern, Erwin-Schroedinger-Str. 46, 67663 Kaiserslautern, Germany — 2Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
2D-Van-der-Waals systems are a highly intriguing class of low dimensional materials with promising spin functionalities for future nanoscale spintronic applications. Here, we show our approach to control the spin and charge carrier dynamics of the Van-der-Waals material WSe2 by the adsorption of CuPc molecules. We conduct time-, angle- and spin-resolved photoemission experiments to investigate the optically excited carrier dynamics at the K- and Σ-points of WSe2. After an initial spin-selective excitation at the K-point, depending on the pump light polarization [1], we observe that the subsequent intraband scattering from the K- to the Σ-point of the bare WSe2 conduction band coincides with a change of the carriers spin polarization. Both, the optical excitation and the subsequent relaxation process can be actively modified by appropriate adsorption of CuPc. In particular, the dominant optical excitation at the K-point of WSe2 is replaced by a direct interlayer excitation from the CuPc into the WSe2 layer. We will show that the strength of the interlayer excitation can be tuned and controlled by the polarization of the exciting light field.
[1] Bertoni et al.; Phys. Rev. Lett. 117, 277201 (2016)