Berlin 2018 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 28: 2D materials: Chalcogenides I (joint session HL/DS)
HL 28.4: Talk
Wednesday, March 14, 2018, 10:15–10:30, A 151
Optical absorption of a mechanically strained WSe2 monolayer — •Iris Niehues1, Robert Schmidt1, Robert Schneider1, Matthias Drüppel2, Torsten Deilmann2, Michael Rohlfing2, Steffen Michaelis de Vasconcellos1, Andres Castellanos-Gomez3, and Rudolf Bratschitsch1 — 1Physikalisches Insitut, Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster — 2Institut für Festkörpertheorie, Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster — 3Materials Science Factory, Instituto de Ciencia de los Materials de Madrid (ICMM-CSIC), E- 28049 Madrid
Atomically thin layers of transition metal dichalcogenides represent a new class of materials. Strain engineering allows to tune their fundamental optical transitions. We apply reversible uniaxial tensile strain of up to 1.4% to a WSe2 monolayer. At increasing and decreasing tensile strain levels absorption spectra are recorded, and the strain-dependent energy shifts of the exciton resonances are measured[1]. Gauge factors of −54 meV/%, −50 meV/%, +1 meV/%, and −22 meV/% are derived for the A, B, C, and D exciton, respectively. A comparison with ab initio GW-BSE calculations shows an excellent agreement with the measured data.
[1] R. Schmidt, I. Niehues, R. Schneider, M. Drüppel, T. Deilmann, M. Rohlfing, S. Michaelis de Vasconcellos, A. Castellanos-Gomez, and R. Bratschitsch, Reversible uniaxial strain tuning in atomically thin WSe2 in: 2D Materials 3, 021011 (2016)