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MA: Fachverband Magnetismus
MA 40: Graphene-like materials: Silicene, MoS2 and relatives (with DY/DS/HL/O/TT)
MA 40.4: Talk
Thursday, April 3, 2014, 10:45–11:00, POT 081
Carrier- and valley dynamics of singlelayer MoS2 — •Gerd Plechinger1, John Mann2, Christian Schüller1, Ludwig Bartels2, and Tobias Korn1 — 1Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany — 2Chemistry, Physics, and Materials Science and Engineering, University of California, CA 92521 Riverside, USA
Consisting of an only 0.7 nm thin S-Mo-S sheet and offering a direct bandgap at the K-points in the Brillouin zone, singlelayer MoS2 represents a promising semiconductor material for flexible and transparent optoelectronic applications. By means of chemical vapor deposition (CVD), large-area films (several mm2) of singlelayer MoS2 can be produced. These were characterised by photoluminescence and Raman spectroscopy. In order to investigate the carrier dynamics, we performed pump-probe measurements in the spectral range of the optical transitions in singelayer MoS2. Helicity-resolved PL measurements have demonstrated an efficient valley polarisation of the K+ or K− valley at near-resonant excitation. We probe these valley dynamics with Kerr spectroscopy and find a biexponential decay of the valley polarisation with decay times of a few tens of ps and a few hundreds of ps at low temperatures.