Ultraviolet interlayer excitons in bilayer WSe 2 .

Autor: Lin KQ; State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China. kaiqiang.lin@xmu.edu.cn.; Department of Physics, University of Regensburg, Regensburg, Germany. kaiqiang.lin@xmu.edu.cn., Faria Junior PE; Department of Physics, University of Regensburg, Regensburg, Germany., Hübner R; Institute for Theoretical Physics and Bremen Center for Computational Materials Science, University of Bremen, Bremen, Germany., Ziegler JD; Institute of Applied Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, Dresden, Germany., Bauer JM; Department of Physics, University of Regensburg, Regensburg, Germany., Buchner F; Department of Physics, University of Regensburg, Regensburg, Germany., Florian M; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA., Hofmann F; Department of Physics, University of Regensburg, Regensburg, Germany., Watanabe K; Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan., Taniguchi T; International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan., Fabian J; Department of Physics, University of Regensburg, Regensburg, Germany., Steinhoff A; Institute for Theoretical Physics and Bremen Center for Computational Materials Science, University of Bremen, Bremen, Germany., Chernikov A; Institute of Applied Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, Dresden, Germany., Bange S; Department of Physics, University of Regensburg, Regensburg, Germany., Lupton JM; Department of Physics, University of Regensburg, Regensburg, Germany.
Jazyk: angličtina
Zdroj: Nature nanotechnology [Nat Nanotechnol] 2024 Feb; Vol. 19 (2), pp. 196-201. Date of Electronic Publication: 2023 Dec 04.
DOI: 10.1038/s41565-023-01544-7
Abstrakt: Interlayer excitons in van der Waals heterostructures are fascinating for applications like exciton condensation, excitonic devices and moiré-induced quantum emitters. The study of these charge-transfer states has almost exclusively focused on band edges, limiting the spectral region to the near-infrared regime. Here we explore the above-gap analogues of interlayer excitons in bilayer WSe 2 and identify both neutral and charged species emitting in the ultraviolet. Even though the transitions occur far above the band edge, the states remain metastable, exhibiting linewidths as narrow as 1.8 meV. These interlayer high-lying excitations have switchable dipole orientations and hence show prominent Stark splitting. The positive and negative interlayer high-lying trions exhibit significant binding energies of 20-30 meV, allowing for a broad tunability of transitions via electric fields and electrostatic doping. The Stark splitting of these trions serves as a highly accurate, built-in sensor for measuring interlayer electric field strengths, which are exceedingly difficult to quantify otherwise. Such excitonic complexes are further sensitive to the interlayer twist angle and offer opportunities to explore emergent moiré physics under electrical control. Our findings more than double the accessible energy range for applications based on interlayer excitons.
(© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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