Dark exciton-exciton annihilation in monolayer WSe2
Artikel i vetenskaplig tidskrift, 2021
The exceptionally strong Coulomb interaction in semiconducting transition-metal dichalcogenides (TMDs) gives rise to a rich exciton landscape consisting of bright and dark exciton states. At elevated densities, excitons can interact through exciton-exciton annihilation (EEA), an Auger-like recombination process limiting the efficiency of optoelectronic applications. Although EEA is a well-known and particularly important process in atomically thin semiconductors determining exciton lifetimes and affecting transport at elevated densities, its microscopic origin has remained elusive. In this joint theory-experiment study combining microscopic and material-specific theory with time- and temperature-resolved photoluminescence measurements, we demonstrate the key role of dark intervalley states that are found to dominate the EEA rate in monolayer WSe2. We reveal an intriguing, characteristic temperature dependence of Auger scattering in this class of materials with an excellent agreement between theory and experiment. Our study provides microscopic insights into the efficiency of technologically relevant Auger scattering channels within the remarkable exciton landscape of atomically thin semiconductors.
Författare
Daniel Erkensten
Chalmers, Fysik, Kondenserad materie- och materialteori
Samuel Brem
Philipps-Universität Marburg
Koloman Wagner
Technische Universität Dresden
Universität Regensburg
Roland Gillen
Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)
Raul Perea Causin
Chalmers, Fysik, Kondenserad materie- och materialteori
2D-Tech
Jonas D. Ziegler
Technische Universität Dresden
Universität Regensburg
Takashi Taniguchi
National Institute for Materials Science (NIMS)
Kenji Watanabe
National Institute for Materials Science (NIMS)
Janina Maultzsch
Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)
Alexey Chernikov
Technische Universität Dresden
Universität Regensburg
Ermin Malic
Philipps-Universität Marburg
Chalmers, Fysik, Kondenserad materie- och materialteori
2D-Tech
Physical Review B
2469-9950 (ISSN) 2469-9969 (eISSN)
Vol. 104 24 L2414062D material-baserad teknologi för industriella applikationer (2D-TECH)
GKN Aerospace Sweden (2D-tech), 2021-01-01 -- 2024-12-31.
VINNOVA (2019-00068), 2020-05-01 -- 2024-12-31.
Graphene 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
10.1103/PhysRevB.104.L241406