Strain fingerprinting of exciton valley character in 2D semiconductors
Artikel i vetenskaplig tidskrift, 2024
Intervalley excitons with electron and hole wavefunctions residing in different valleys determine the long-range transport and dynamics observed in many semiconductors. However, these excitons with vanishing oscillator strength do not directly couple to light and, hence, remain largely unstudied. Here, we develop a simple nanomechanical technique to control the energy hierarchy of valleys via their contrasting response to mechanical strain. We use our technique to discover previously inaccessible intervalley excitons associated with K, Γ, or Q valleys in prototypical 2D semiconductors WSe2 and WS2. We also demonstrate a new brightening mechanism, rendering an otherwise “dark” intervalley exciton visible via strain-controlled hybridization with an intravalley exciton. Moreover, we classify various localized excitons from their distinct strain response and achieve large tuning of their energy. Overall, our valley engineering approach establishes a new way to identify intervalley excitons and control their interactions in a diverse class of 2D systems.
Författare
Abhijeet M. Kumar
Freie Universität Berlin
Denis Yagodkin
Freie Universität Berlin
Roberto Rosati
Philipps-Universität Marburg
Douglas J. Bock
Freie Universität Berlin
Christoph Schattauer
Technische Universität Wien
Sarah Tobisch
Technische Universität Wien
Joakim Hagel
Chalmers, Fysik, Kondenserad materie- och materialteori
Bianca Höfer
Freie Universität Berlin
Jan N. Kirchhof
Freie Universität Berlin
Kavli Institute of Nanoscience Delft
Pablo Hernández López
Humboldt-Universität zu Berlin
Kenneth Burfeindt
Freie Universität Berlin
Sebastian Heeg
Humboldt-Universität zu Berlin
Cornelius Gahl
Freie Universität Berlin
Florian Libisch
Technische Universität Wien
Ermin Malic
Philipps-Universität Marburg
Kirill I. Bolotin
Freie Universität Berlin
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 15 1 7546Ämneskategorier (SSIF 2025)
Atom- och molekylfysik och optik
Den kondenserade materiens fysik
Annan fysik
DOI
10.1038/s41467-024-51195-y
Relaterade dataset
Strain fingerpringting of exciton valley character in 2D semiconductors [dataset]
URI: https://zenodo.org/records/12699607