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HL: Fachverband Halbleiterphysik
HL 14: Poster: Two-Dimenaional Materials and Topological Insulators
HL 14.5: Poster
Monday, March 20, 2017, 14:00–18:00, P2-OG3
G-factor determination of excitonic states in monolayer tungsten disulfide (WS2) — •Jan Kuhnert, Simon Schmitt, Arash Rahimi-Iman, and Wolfram Heimbrodt — Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany
Layered transition-metal dichalcogenides have attracted great interest in the last few years. Thinned down to monolayers they exhibit outstanding optical properties caused by the direct band gap. Here, we present photoluminescence (PL) measurements of tungsten disulfide monolayers at low temperatures (2 K) in the presence of an external magnetic field in Faraday geometry. In the monolayer limit the inversion symmetry is broken and spin and valley are coupled. The degeneracy between the two equivalent k and k* valleys is broken by applying external magnetic fields. This causes a Zeeman shift of the peak positions of each excitonic species. By fitting the measured PL spectra we determine the g-factors for the free excitonic transitions: exciton and trion; and for three bound exciton states that exhibit slightly different g-factors due to different localization lengths.