Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 35: Ultrafast Phenomena I
O 35.4: Talk
Tuesday, March 8, 2016, 10:15–10:30, H10
Internal structure and ultrafast dynamics of excitons in monolayer WSe2 — •Christoph Pöllmann1, Philipp Steinleitner1, Ursula Leierseder1, Philipp Nagler1, Gerd Plechinger1, Michael Porer1, Rudolph Bratschitsch2, Christian Schüller1, Tobias Korn1, and Rupert Huber1 — 1Department of Physics, University of Regensburg, 93040 Regensburg, Germany — 2Institute of Physics, University of Münster, 48149 Münster, Germany
Atomically thin transition metal dichalcogenides (TMDCs) promise groundbreaking optoelectronic applications and devices due to their direct bandgap in the optical range. As a consequence of the layered structure, unusually strongly bound excitons can exist even at room temperature, dominating the optical and electronical properties. In order to exploit the full potential of this new material system, key open questions regarding the excitons in TMDC monolayers have to be answered. Here we report the first direct observation of the intraexcitonic 1s-2p transition via time resolved pump/THz probe studies, tracing both optically bright and dark exciton states. Beside quantitative information about transition energies, oscillator strengths, linewidths and many-body effects a record fast radiative decay of bright excitons with a time constant of only 150 fs can be revealed.