Excitonic complexes in $n$-doped WS$_2$ monolayer

M. Zinkiewicz; T. Woźniak; T. Kazimierczuk; P. Kapuściński; K. Oreszczuk; M. Grzeszczyk; M. Bartos; K. Nogajewski; K. Watanabe; T. Taniguchi; C. Faugeras; P. Kossacki; M. Potemski; A. Babiński; M. R. Molas

doi:10.1021/acs.nanolett.0c05021

arXiv · 2012.11509

Excitonic complexes in $n$-doped WS$_2$ monolayer

M. Zinkiewicz·T. Woźniak·T. Kazimierczuk·P. Kapuściński·K. Oreszczuk·M. Grzeszczyk·M. Bartos·K. Nogajewski·K. Watanabe·T. Taniguchi·C. Faugeras·P. Kossacki·M. Potemski·A. Babiński·M. R. Molas

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Abstract

We investigate the origin of emission lines apparent in the low-temperature photoluminescence spectra of $n$-doped WS$_2$ monolayer embedded in hexagonal BN layers using external magnetic fields and first-principles calculations. Apart from the neutral A exciton line, all observed emission lines are related to the negatively charged excitons. Consequently, we identify emissions due to both the bright (singlet and triplet) and dark (spin- and momentum-forbidden) negative trions as well as the phonon replicas of the latter optically-inactive complexes. The semi-dark trions and negative biexcitons are distinguished. Based on their experimentally extracted and theoretically calculated $g$-factors, we identify three distinct families of emissions due to exciton complexes in WS$_2$: bright, intravalley and intervalley dark. The $g$-factors of the spin-split subbands in both the conduction and valence bands are also determined.

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M. Zinkiewicz, T. Woźniak, T. Kazimierczuk, P. Kapuściński, K. Oreszczuk, M. Grzeszczyk, M. Bartos, K. Nogajewski, K. Watanabe, T. Taniguchi, C. Faugeras, P. Kossacki, M. Potemski, A. Babiński, M. R. Molas. 2020-12-21. Excitonic complexes in $n$-doped WS$_2$ monolayer. https://doi.org/10.1021/acs.nanolett.0c05021

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