Regensburg 2019 – scientific programme

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O: Fachverband Oberflächenphysik

O 53: 2D Materials II: Transition Metal Dichalcogenides

O 53.11: Talk

Wednesday, April 3, 2019, 13:00–13:15, H16

Exciton landscape of mono- and bilayer transition metal dichalcogenides — •Thorsten Deilmann and Kristian Sommer Thygesen — CAMD, Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark

Monolayers and bilayers of transition metal dichalcogenides are intensively studied, in particular due to their rich opto-electronic properties. Until now the main focus has been the investigation of (bright) excitons with zero momentum. In this study we employ ab initio many-body perturbation theory within the GW/BSE approximation to describe the entire q-resolved exciton band structure for mono- and bilayers of the MX₂ (M = Mo, W and X = Se, S) TMDCs.

We find that excitonic effects strongly influence the exciton band structure. However, energy differences between extrema with varied exciton momenta can be described fairly well already within DFT.