Abstract
Transition metal dichalcogenide (TMD) heterobilayers provide a versatile platform to explore unique excitonic physics via the properties of the constituent TMDs and external stimuli. Interlayer excitons (IXs) can form in TMD heterobilayers as delocalized or localized states. However, the localization of IX in different types of potential traps, the emergence of biexcitons in the high-excitation regime, and the impact of potential traps on biexciton formation have remained elusive. In our work, we observe two types of potential traps in a MoSe2/WSe2 heterobilayer, which result in significantly different emission behavior of IXs at different temperatures. We identify the origin of these traps as localized defect states and the moiré potential of the TMD heterobilayer. Furthermore, with strong excitation intensity, a superlinear emission behavior indicates the emergence of interlayer biexcitons, whose formation peaks at a specific temperature. Our work elucidates the different excitation and temperature regimes required for the formation of both localized and delocalized IX and biexcitons and, thus, contributes to a better understanding and application of the rich exciton physics in TMD heterostructures.
| Original language | English |
|---|---|
| Article number | 6910 |
| Journal | Nature Communications |
| Volume | 14 |
| Issue number | 1 |
| Number of pages | 7 |
| ISSN | 2041-1723 |
| DOIs | |
| Publication status | Published - Dec 2023 |
Bibliographical note
Funding Information:H.F. and W.W. acknowledge support by Olle Engkvists Stiftelse, Carl Tryggers Stiftelse, and together with S.D. by Chalmers Area of Advance Nano. W.W. acknowledges support from the Knut and Alice Wallenberg Foundation through a Wallenberg Academy Fellowship. Samples were fabricated in the Myfab Nanofabrication Laboratory at Chalmers. S.D. acknowledges financial support from European Union Graphene Flagship (Core 3, No. 881603), 2D TECH VINNOVA center (No. 2019-00068). Q.L. and S.X. acknowledge the support from the Independent Research Fund Denmark (project no. 9041-00333B and 2032-00351B), Direktør Ib Henriksens Fond, and Brødrene Hartmanns Fond. Y.Z. and Z.S. acknowledge the support from Horizon Europe (HORIZON) Project: ChirLog (101067269), the Academy of Finland (grants 314810, 333982, 336144, 336818, 352780, and 353364), Academy of Finland Flagship Programme (320167, PREIN), the EU H2020-MSCA-RISE-872049 (IPN-Bio), and ERC advanced grant (834742). E.M. acknowledges support from Deutsche Forschungsgemeinschaft (DFG) via CRC 1083 (project B09).
Funding Information:
H.F. and W.W. acknowledge support by Olle Engkvists Stiftelse, Carl Tryggers Stiftelse, and together with S.D. by Chalmers Area of Advance Nano. W.W. acknowledges support from the Knut and Alice Wallenberg Foundation through a Wallenberg Academy Fellowship. Samples were fabricated in the Myfab Nanofabrication Laboratory at Chalmers. S.D. acknowledges financial support from European Union Graphene Flagship (Core 3, No. 881603), 2D TECH VINNOVA center (No. 2019-00068). Q.L. and S.X. acknowledge the support from the Independent Research Fund Denmark (project no. 9041-00333B and 2032-00351B), Direktør Ib Henriksens Fond, and Brødrene Hartmanns Fond. Y.Z. and Z.S. acknowledge the support from Horizon Europe (HORIZON) Project: ChirLog (101067269), the Academy of Finland (grants 314810, 333982, 336144, 336818, 352780, and 353364), Academy of Finland Flagship Programme (320167, PREIN), the EU H2020-MSCA-RISE-872049 (IPN-Bio), and ERC advanced grant (834742). E.M. acknowledges support from Deutsche Forschungsgemeinschaft (DFG) via CRC 1083 (project B09).
Publisher Copyright:
© 2023, The Author(s).