The effect of dielectric environment on the brightening of neutral and charged dark excitons in WSe2 monolayer

Autor: Małgorzata Zinkiewicz, Magdalena Grzeszczyk, Łucja Kipczak, Tomasz Kazimierczuk, Kenji Watanabe, Takashi Taniguchi, Piotr Kossacki, Adam Babiński, Maciej R. Molas
Rok vydání: 2022
Předmět:
Zdroj: Applied Physics Letters. 120:163101
ISSN: 1077-3118
0003-6951
Popis: The dielectric environment of atomically-thin monolayer (ML) of semiconducting transition metal dichalcogenides affects both the electronic band gap and the excitonic binding energy in the ML. We investigate the effect of the environment on the in-plane magnetic field brightening of neutral and charged dark exciton emissions in the WSe$_2$ ML. The monolayers placed in three dielectric environments are studied, in particular, the ML encapsulated in hexagonal BN (hBN) flakes, the ML deposited on a hBN layer, and the ML embedded between the hBN flake and SiO$_2$/Si substrate. We observe that the brightening rates of the neutral and charged dark excitons depend on the dielectric environment, which may be related to the variation of the level of carrier concentration in the ML. Moreover, the surrounding media, characterized by different dielectric constants, influences weakly the relative energies of the neutral and charged dark excitons in reference to the bright ones.
5 pages, 4 figures
Databáze: OpenAIRE