Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 48: Poster: 2D Materials beyond Graphene: TMDCs, Silicene and Relatives
O 48.9: Poster
Dienstag, 13. März 2018, 18:15–20:30, Poster A
Time-resolved photoemission electron microscopy on monolayered WSe2 — •Bernhard Huber1, Sebastian Pres1, Bernhard Mahlmeister1, Daniel Fersch1, Victor Lisinetskii1, Steffen Michaelis de Vasconcellos2, Robert Schneider2, Johannes Kern2, Matthias Hensen1, Rudolf Bratschitsch2, and Tobias Brixner1 — 1Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg — 2Physikalisches Institut, Wilhelm-Klemm-Str. 10, 48149 Münster
Atomically thin transition metal dichalcogenides (TMDCs) have emerged as a promising material system for optoelectronic applications, e.g., as a single-photon source, which was recently demonstrated with a single layer of WSe2 [1]. Here we present time-resolved photoemission electron microscopy (TR-PEEM) results on WSe2 in a pump–probe spectroscopy scheme revealing spatio–temporal features at the 100 nm length scale. As illumination source a widely tunable high-repetition-rate (1 MHz) laser system pumping a non-collinear optical parametric amplifier is used, providing pulses from 900 nm down to 230 nm. In the presented experiment, a pump pulse centered at 700 nm excites slightly above the A exciton resonance (1.63 eV) which occurs at the K and K’ points of the Brillouin zone. A probe pulse (350 nm) consequently transfers the excited-state manifold into photoemitted electrons which are detected with PEEM.
[1] J. Kern et al., Adv. Mater. 2016, 28, 7101–7105