Hoegele, Alexander

Date:  Thursday, February 22, 2018
Time:  14:00
Place:  ETH Zurich, Hönggerberg, HPF G 6
Host:  Atac Imamoglu

Seeing dark excitons in atomically thin semiconductors

Alexander Högele
Ludwig-Maximilians-Universität, Munich, Germany

Atomically thin semiconductors in the form of transition metal dichalcogenides have emerged recently as novel truly two-dimensional materials with remarkable opto-electronic properties. In response to an optical excitation, they host strongly bound electron-hole pairs, so-called excitons, with unique spin and valley degrees of freedom. 
While the photophysics of bright excitons with dipole-allowed optical transitions have been meanwhile well established, the role of dark excitons remains mostly unexplored. In my presentation, I will discuss signatures of dark excitons in the photoluminescence spectra of monolayer, bilayer and hetero-bilayer systems, and how their notion complements our understanding of optical excitations in atomically thin semiconductors.