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Vertically stacked transition metal dichalcogenide (TMD) heterostructures provide an opportunity to explore optoelectronic properties within the two-dimensional limit. In such structures, spatially indirect interlayer excitons (IXs) can be generated in adjacent layers because of strong Coulomb interactions. However, due to the complexity of the multilayered heterostructure (HS), the capture and study of the IXs in trilayer type-II HSs have so far remained elusive. Here, we present the observation of the IXs in trilayer type-II staggered band alignment of MoS2/MoSe2/WSe2 van der Waals (vdW) HSs by photoluminescence (PL) spectroscopy. The central energy of IX is 1.33 eV, and the energy difference between the extracted double peaks is 23 meV. We confirmed the origin of IX through PL properties and calculations by the density functional theory, we also studied the dependence of the IX emission peak on laser power and temperature. Furthermore, the polarization-resolved PL spectra of HS were also investigated, and the maximum polarizability of the emission peak of WSe2 reached 11.40% at 6 K. Our findings offer opportunities for the study of new physical properties of excitons in TMD HSs and therefore are valuable for exploring the potential applications of TMDs in optoelectronic devices.

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Publication history

Received: 10 May 2022
Revised: 23 May 2022
Accepted: 24 May 2022
Published: 22 June 2022
Issue date: October 2022

Copyright

© Tsinghua University Press 2022

Acknowledgements

Acknowledgment

We appreciate the support of the Hunan Province’s Key Research and Development Project (No. 2019GK2233), the National Natural Science Foundation of China (No. 61775241), the Hunan Science Fund for Distinguished Young Scholar (No. 2020JJ2059), Youth Innovation Team (No. 2019012) of CSU, Hunan Province Graduate Research and Innovation Project (No. CX20190177), and the Science and Technology Innovation Basic Research Project of Shenzhen (No. JCYJ20190806144418859). Also, Y. P. L. acknowledges the support from the Central South University of the State Key Laboratory of High-Performance Complex Manufacturing Project (No. ZZYJKT2020-12). Z. W. L. thanks to the financial support from the Australian Research Council (ARC Discovery Projects, Nos. DP210103539, DP180102976, and DP130104231).

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