2018/05/28 by Alex Krasnok, Andrea Alù, Krasnok, Alex +1 · 1 citation
Engineering · Materials Science · #2D Materials and Applications #Applied Physics (physics.app-ph) #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Optics (physics.optics) #Perovskite Materials and Applications #Plasmonic and Surface Plasmon Research
paper · pdf · doi:10.48550/arxiv.1805.11177
openalex publication_date 2018/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Monolayer (1L) transition metal dichalcogenides (TMDCs) are attractive materials for several optoelectronic applications because of their strong excitonic resonances and valley-selective response. Valley excitons in 1L-TMDCs are formed at opposite points of the Brillouin zone boundary, giving rise to a valley degree of freedom that can be treated as a pseudospin and may be used as a platform for information transport and processing. However, short valley depolarization times and relatively short exciton lifetimes at room temperature prevent using valley pseudospin in on-chip integrated valley devices. Recently it has been demonstrated how coupling these materials to optical nanoantennas and metasurfaces can overcome this obstacle. Here, we review the state-of-the-art advances in valley-selective directional emission and exciton sorting in 1L-TMDC mediated by nanostructures and nanoantennas. We briefly discuss the optical properties of 1L-TMDCs paying special attention to their photoluminescence/absorption spectra, dynamics of valley depolarization and valley Hall effect. Then, we review recent works on nanostructures for valley-selective directional emission from 1L-TMDCs.