Dresden 2020 – wissenschaftliches Programm
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DS 4.7: Vortrag
Montag, 16. März 2020, 11:30–11:45, POT 81
Interlayer excitons in MoSe2/WSe2 heterobilayers — •Johannes Michl1, Oliver Iff1, Maximilian Waldherr1, Sefaattin Tongay2, Martin Kamp1, Sven Höfling1, and Christian Schneider1 — 1Technische Physik, Physikalisches Institut and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany — 2Arizona State University
Two dimensional materials such as monolayers of transition metal dichalcogenides (TMDs) offer a wide range of possibilities for investigation due to their unique optical properties, resulting from the exotic valley physics and the strong Coulomb interaction. By stacking two different TMDs, a van der Waals heterostructure is formed. This heterobilayer can exhibit a type-II band alignment, enabling formation of interlayer excitons, with the electron and the hole residing in separate layers. As the heterobilayer is formed, spatially periodical moiré potentials occur due to the lattice mismatch and twist of the different monolayer materials. The moiré potential is predicted to have a great impact on the interaction of light with the interlayer excitons. We discuss the observation of interlayer excitons in MoSe2/WSe2 heterobilayers performing µ-PL measurements. Due to the weaker coupling strength between the electron and hole in the spatially separated arrangement, the luminscence from the interlayer excitons is shifted around 200 nanometers. The interlayer excitonic resonance is further characterized by a distinct, non-trivial peak structure, which indicates the involvement of a moiré superpotential.