Angle- and polarization-resolved luminescence from suspended and hexagonal boron nitride encapsulated MoSe2 monolayers
Artikel i vetenskaplig tidskrift, 2022
The polarized photoluminescence from atomically thin transition metal dichalcogenides is a frequently applied tool to scrutinize optical selection rules and valley physics, yet it is known to sensibly depend on a variety of internal and external material and sample properties. In this work, we apply combined angle- and polarization-resolved spectroscopy to explore the interplay of excitonic physics and phenomena arising from the commonly utilized encapsulation procedure on the optical properties of atomically thinMoSe2.We probe monolayers prepared in both suspended and encapsulated manners.We show that the hBN encapsulation significantly enhances the linear polarization of exciton photoluminescence emission at large emission angles. This degree of linear polarization of excitons can increase up to ∼17% in the hBN encapsulated samples. As we confirm by finite-difference time-domain simulations, it can be directly connected to the optical anisotropy of the hBN layers. In comparison, the linear polarization at finite exciton momenta is significantly reduced in a suspendedMoSe2 monolayer, and becomes notable only in cryogenic conditions. This phenomenon strongly suggests that the effect is rooted in the k-dependent anisotropic exchange coupling inherent in2Dexcitons.Our results have strong implications on further studies on valley contrasting selection rules and valley coherence phenomena using standard suspended and encapsulated samples.
Molybdenum compounds
Anisotropy
Finite difference time domain method
Excitons
photoluminescence
Författare
Bo Han
Carl von Ossietzky Universität Oldenburg
Sven Stephan
Carl von Ossietzky Universität Oldenburg
J. J.P. Thompson
Philipps-Universität Marburg
Martin Esmann
Carl von Ossietzky Universität Oldenburg
Carlos Anton-Solanas
Carl von Ossietzky Universität Oldenburg
Hangyong Shan
Carl von Ossietzky Universität Oldenburg
Nils Kunte
Carl von Ossietzky Universität Oldenburg
Samuel Brem
Chalmers, Fysik, Kondenserad materie- och materialteori
Sefaattin Tongay
Arizona State University
Christoph Lienau
Carl von Ossietzky Universität Oldenburg
Kenji Watanabe
National Institute for Materials Science (NIMS)
Takashi Taniguchi
National Institute for Materials Science (NIMS)
Martin Silies
Carl von Ossietzky Universität Oldenburg
Ermin Malic
Philipps-Universität Marburg
Chalmers, Fysik, Kondenserad materie- och materialteori
Christian Schneider
Carl von Ossietzky Universität Oldenburg
Optica
2334-2536 (ISSN)
Vol. 9 10 1190-1196Graphene Core Project 3 (Graphene Flagship)
Europeiska kommissionen (EU) (EC/H2020/881603), 2020-04-01 -- 2023-03-31.
Ämneskategorier
Atom- och molekylfysik och optik
Annan fysik
Den kondenserade materiens fysik
DOI
10.1364/OPTICA.464533