Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Moiré trions in MoSe2/WSe2 heterobilayers


Transition metal dichalcogenide moiré bilayers with spatially periodic potentials have emerged as a highly tunable platform for studying both electronic1,2,3,4,5,6 and excitonic4,7,8,9,10,11,12,13 phenomena. The power of these systems lies in the combination of strong Coulomb interactions with the capability of controlling the charge number in a moiré potential trap. Electronically, exotic charge orders at both integer and fractional fillings have been discovered2,5. However, the impact of charging effects on excitons trapped in moiré potentials is poorly understood. Here, we report the observation of moiré trions and their doping-dependent photoluminescence polarization in H-stacked MoSe2/WSe2 heterobilayers. We find that as moiré traps are filled with either electrons or holes, new sets of interlayer exciton photoluminescence peaks with narrow linewidths emerge about 7 meV below the energy of the neutral moiré excitons. Circularly polarized photoluminescence reveals switching from co-circular to cross-circular polarizations as moiré excitons go from being negatively charged and neutral to positively charged. This switching results from the competition between valley-flip and spin-flip energy relaxation pathways of photo-excited electrons during interlayer trion formation. Our results offer a starting point for engineering both bosonic and fermionic many-body effects based on moiré excitons14.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Moiré trions are formed with electrostatic gating.
Fig. 2: Zeeman splitting of both neutral and charged moiré excitons.
Fig. 3: Doping-dependent valley polarization of moiré trions.
Fig. 4: Moiré exciton and trion dynamics.

Data availability

Source data are provided with this paper. All other data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.


  1. Shimazaki, Y. et al. Strongly correlated electrons and hybrid excitons in a moiré heterostructure. Nature 580, 472–477 (2020).

    Article  CAS  Google Scholar 

  2. Regan, E. C. et al. Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices. Nature 579, 359–363 (2020).

    Article  CAS  Google Scholar 

  3. Tang, Y. et al. Simulation of Hubbard model physics in WSe2/WS2 moiré superlattices. Nature 579, 353–358 (2020).

    Article  CAS  Google Scholar 

  4. Sung, J. et al. Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe2/MoSe2 bilayers. Nat. Nanotechnol. 15, 750–754 (2020).

    Article  CAS  Google Scholar 

  5. Xu, Y. et al. Correlated insulating states at fractional fillings of moiré superlattices. Nature 587, 214–218 (2020).

    Article  CAS  Google Scholar 

  6. Wang, L. et al. Correlated electronic phases in twisted bilayer transition metal dichalcogenides. Nat. Mater. 19, 861–866 (2020).

    Article  CAS  Google Scholar 

  7. Jin, C. et al. Observation of moiré excitons in WSe2/WS2 heterostructure superlattices. Nature 567, 76–80 (2019).

    Article  CAS  Google Scholar 

  8. Alexeev, E. M. et al. Resonantly hybridized excitons in moiré superlattices in van der Waals heterostructures. Nature 567, 81–86 (2019).

    Article  CAS  Google Scholar 

  9. Bai, Y. et al. Excitons in strain-induced one-dimensional moiré potentials at transition metal dichalcogenide heterojunctions. Nat. Mater. 19, 1068–1073 (2020).

    Article  CAS  Google Scholar 

  10. Seyler, K. L. et al. Signatures of moiré-trapped valley excitons in MoSe2/WSe2 heterobilayers. Nature 567, 66–70 (2019).

    Article  CAS  Google Scholar 

  11. Tran, K. et al. Evidence for moiré excitons in van der Waals heterostructures. Nature 567, 71–75 (2019).

    Article  CAS  Google Scholar 

  12. Brotons-Gisbert, M. et al. Spin–layer locking of interlayer excitons trapped in moiré potentials. Nat. Mater. 19, 630–636 (2020).

    Article  CAS  Google Scholar 

  13. Baek, H. et al. Highly energy-tunable quantum light from moiré-trapped excitons. Sci. Adv. 6, eaba8526 (2020).

    Article  CAS  Google Scholar 

  14. Combescot, M., Betbeder-Matibet, O. & Dubin, F. The many-body physics of composite bosons. Phys. Rep. 463, 215–320 (2008).

    Article  CAS  Google Scholar 

  15. Rivera, P. et al. Interlayer valley excitons in heterobilayers of transition metal dichalcogenides. Nat. Nanotechnol. 13, 1004–1015 (2018).

    Article  CAS  Google Scholar 

  16. Zhang, C. et al. Interlayer couplings, moiré patterns, and 2D electronic superlattices in MoS2/WSe2 hetero-bilayers. Sci. Adv. 3, e1601459 (2017).

    Article  CAS  Google Scholar 

  17. Wilson, N. R. et al. Determination of band offsets, hybridization, and exciton binding in 2D semiconductor heterostructures. Sci. Adv. 3, e1601832 (2017).

    Article  CAS  Google Scholar 

  18. Ruiz-Tijerina, D. A. & Fal’Ko, V. I. Interlayer hybridization and moiré superlattice minibands for electrons and excitons in heterobilayers of transition-metal dichalcogenides. Phys. Rev. B 99, 125424 (2019).

    Article  CAS  Google Scholar 

  19. Yuan, L. et al. Twist-angle-dependent interlayer exciton diffusion in WS2–WSe2 heterobilayers. Nat. Mater. 19, 617–623 (2020).

    Article  CAS  Google Scholar 

  20. Li, W., Lu, X., Dubey, S., Devenica, L. & Srivastava, A. Dipolar interactions between localized interlayer excitons in van der Waals heterostructures. Nat. Mater. 19, 624–629 (2020).

    Article  CAS  Google Scholar 

  21. Yu, H. et al. Moiré excitons: from programmable quantum emitter arrays to spin-orbit–coupled artificial lattices. Sci. Adv. 3, e1701696 (2017).

    Article  CAS  Google Scholar 

  22. McGilly, L. J. et al. Visualization of moiré superlattices. Nat. Nanotechnol. 15, 580–584 (2020).

    Article  CAS  Google Scholar 

  23. Wang, Z., Zhao, L., Mak, K. F. & Shan, J. Probing the spin-polarized electronic band structure in monolayer transition metal dichalcogenides by optical spectroscopy. Nano Lett. 17, 740–746 (2017).

    Article  CAS  Google Scholar 

  24. Mak, K. F. et al. Tightly bound trions in monolayer MoS2. Nat. Mater. 12, 207–211 (2013).

    Article  CAS  Google Scholar 

  25. Ross, J. S. et al. Electrical control of neutral and charged excitons in a monolayer semiconductor. Nat. Commun. 4, 1474 (2013).

    Article  CAS  Google Scholar 

  26. Ross, J. S. et al. Interlayer exciton optoelectronics in a 2D heterostructure p–n junction. Nano Lett. 17, 638–643 (2017).

    Article  CAS  Google Scholar 

  27. Bondarev, I. V. & Vladimirova, M. R. Complexes of dipolar excitons in layered quasi-two-dimensional nanostructures. Phys. Rev. B 97, 165419 (2018).

    Article  CAS  Google Scholar 

  28. Jauregui, L. A. et al. Electrical control of interlayer exciton dynamics in atomically thin heterostructures. Science 366, 870–875 (2019).

    Article  CAS  Google Scholar 

  29. Rivera, P. et al. Observation of long-lived interlayer excitons in monolayer MoSe2–WSe2 heterostructures. Nat. Commun. 6, 6242 (2015).

    Article  CAS  Google Scholar 

  30. Tang, Y. et al. Tuning layer-hybridized moiré excitons by the quantum-confined Stark effect. Nat. Nanotechnol. 16, 52–57 (2020).

    Article  CAS  Google Scholar 

  31. Wang, T. et al. Giant valley-Zeeman splitting from spin-singlet and spin-triplet interlayer excitons in WSe2/MoSe2 heterostructure. Nano Lett. 20, 694–700 (2020).

    Article  CAS  Google Scholar 

  32. Ciarrocchi, A. et al. Polarization switching and electrical control of interlayer excitons in two-dimensional van der Waals heterostructures. Nat. Photonics 13, 131–136 (2019).

    Article  CAS  Google Scholar 

  33. Yu, H., Liu, G.-B. & Yao, W. Brightened spin-triplet interlayer excitons and optical selection rules in van der Waals heterobilayers. 2D Mater 5, 035021 (2018).

    Article  CAS  Google Scholar 

  34. He, M. et al. Valley phonons and exciton complexes in a monolayer semiconductor. Nat. Commun. 11, 618 (2020).

    Article  CAS  Google Scholar 

  35. Movva, H. C. P. et al. Density-dependent quantum hall states and Zeeman splitting in monolayer and bilayer WSe2. Phys. Rev. Lett. 118, 247701 (2017).

    Article  Google Scholar 

Download references


Research on moiré trions is primarily supported as part of Programmable Quantum Materials, an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. Zeeman-splitting and time-resolved measurements are mainly supported by DoE BES under award DE-SC0018171. Device fabrication is partially supported by the Army Research Office (ARO) Multidisciplinary University Research Initiative (MURI) Program (grant no. W911NF-18-1-0431) and the NSF EFRI (grant no. 1741656). The AFM-related measurements were performed using instrumentation supported by the US National Science Foundation through the UW Molecular Engineering Materials Center (MEM·C), a Materials Research Science and Engineering Center (DMR-1719797). W.Y. and H.Z. acknowledge support from the Croucher Foundation (Croucher Senior Research Fellowship) and the University Grant Committee/Research Grants Council of Hong Kong SAR (AoE/P-701/20). D.G.M. and J.Y. are supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by MEXT, Japan (grant no. JPMXP0112101001), JSPS KAKENHI (grant no. JP20H00354) and CREST (JPMJCR15F3), JST. X.X. acknowledges the support from the State of Washington funded Clean Energy Institute and from the Boeing Distinguished Professorship in Physics.

Author information

Authors and Affiliations



X.X. and W.Y. conceived the experiment. X.W. and J.Z. fabricated the samples, assisted by Y.W. and M.H. The measurements were performed by X.W. and J.Z. Device D2 was fabricated and measurements were performed by K.L.S. and P.R. The results were analysed and interpreted by X.W., J.Z., H.Z. X.X., W.Y. and D.R.G. Crystals of BN were synthesized by T.T. and K.W. Bulk WSe2 and MoSe2 crystals were synthesized and characterized by J.Y. and D.G.M. The paper was written by X.W., X.X., W.Y. and D.R.G. with input from all authors. All authors discussed the results.

Corresponding authors

Correspondence to Wang Yao or Xiaodong Xu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Nanotechnology thanks Igor Bondarev, Libai Huang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Text and Figs. 1–8.

Source data

Source Data Fig. 1

Unprocessed data for Fig. 1.

Source Data Fig. 2

Unprocessed data for Fig. 2.

Source Data Fig. 3

Unprocessed data for Fig. 3.

Source Data Fig. 4

Unprocessed data for Fig. 4.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, X., Zhu, J., Seyler, K.L. et al. Moiré trions in MoSe2/WSe2 heterobilayers. Nat. Nanotechnol. 16, 1208–1213 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research