Low-threshold interlayer exciton multiplication in twisted transition metal dichalcogenides heterobilayers

Pengzhi Wang; Gan Wang; Chenhao Wang; Qi Wei; Yuxuan Chen; Qi Liu; Luwei Zhou; Hui Ren; Xiang Zhang; Jiangbo Peng; Leyi Zhao; Tao-Yuan Du; Mingjie Li

doi:10.1038/s41377-026-02193-w

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Low-threshold interlayer exciton multiplication in twisted transition metal dichalcogenides heterobilayers

Original Articles

- Low-threshold interlayer exciton multiplication in twisted transition metal dichalcogenides heterobilayers
- Light: Science & Applications Vol. 15, Issue 4, Pages: 1261-1273(2026)
- Affiliations：
  
  1.Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, China
  2.School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China
  3.Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, China
  4.Photonics Research Institute, The Hong Kong Polytechnic University, Hung Hom, Kowloon, China
- Author bio：
  
  Tao-Yuan Du (duty710@163.com)
  Mingjie Li (ming-jie.li@polyu.edu.hk)
- Funds：
- DOI：10.1038/s41377-026-02193-w
  CLC：
- Received：23 February 2025，
  
  Revised：2025-12-10，
  
  Accepted：12 January 2026，
  
  Online First：10 February 2026，
  
  Published：30 April 2026
- Accepted：
Scan QR Code
Wang, P. Z. et al. Low-threshold interlayer exciton multiplication in twisted transition metal dichalcogenides heterobilayers. Light: Science & Applications, 15, 1261-1273 (2026).
DOI：

Wang, P. Z. et al. Low-threshold interlayer exciton multiplication in twisted transition metal dichalcogenides heterobilayers. Light: Science & Applications, 15, 1261-1273 (2026). DOI： 10.1038/s41377-026-02193-w.

摘要

Abstract

Multiple exciton generation (MEG) from single-photon absorption can enhance quantum efficiencies in light emission and energy conversion. However

its practical application is limited by high photon-energy thresholds

large material bandgaps

and rapid exciton recombination. Here

we report the observation of interlayer exciton multiplication (IXM) in twisted van der Waals heterobilayers

where the process threshold is as low as twice the type-Ⅱ bandgap and the resulting multiple interlayer excitons (IXs) exhibit nanosecond-scale lifetimes. These properties directly address the core challenges of MEG

leading to a significant boost in both interlayer exciton emission and photocurrent quantum efficiency. Theoretical calculations confirm the experimental results

revealing that low-threshold IXM is facilitated by interlayer hot-carrier scattering and is accompanied by attractive IX interactions

even at larger twist angles where momentum mismatch is significant. Twist-angle-induced momentum mismatches have a minimal impact on the IXM threshold due to strong hot-carrier interlayer transfer and efficient intervalley impact ionization. The IXM efficiency reaches ~90% in small-twist-angle heterobilayers but decreases at larger angles and higher pump photon energies

a trend attributed to reduced interlayer hot-carrier Coulomb scattering. Furthermore

we demonstrate photocurrent multiplication driven by IXM. Applied electric fields further lower the IXM threshold and increase the IX yield

enabling a twofold enhancement in quantum efficiency and a fourfold increase in responsivity in a self-powered heterobilayer photodiode. Our results establish IXM as a promising mechanism for high-efficiency carrier-multiplication optoelectronics and provide insights into the many-body physics of stable multiple excitons.

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references

Zhang, Y. Z. et al. Internal quantum efficiency higher than 100% achieved by combining doping and quantum effects for photocatalytic overall water splitting. Nat. Energy 8 , 504–514 (2023)..

Cirloganu, C. M. et al. Enhanced carrier multiplication in engineered quasi-type-Ⅱ quantum dots. Nat. Commun. 5 , 4148 (2014)..

Arnold, D., Cartier, E. & Dimaria, D. J. Acoustic-phonon runaway and impact ionization by hot electrons in silicon dioxide. Phys. Rev. B 45 , 1477–1480 (1992)..

Cao, L. N. et al. Experimental characterization of impact ionization coefficients for electrons and holes in GaN grown on bulk GaN substrates. Appl. Phys. Lett. 112 , 262103 (2018)..

Wolf, M. et al. Solar cell efficiency and carrier multiplication in Si 1-x Ge x alloys. J. Appl. Phys. 83 , 4213–4221 (1998)..

Christensen, O. Quantum efficiency of the internal photoelectric effect in silicon and germanium. J. Appl. Phys. 47 , 689–695 (1976)..

Robbins, D. J. Aspects of the theory of impact ionization in semiconductors (I). Phys. Status Solidi (B) 97 , 9–50 (1980)..

Schaller, R. D. & Klimov, V. I. High efficiency carrier multiplication in PbSe nanocrystals: implications for solar energy conversion. Phys. Rev. Lett. 92 , 186601 (2004)..

Midgett, A. G. et al. Size and composition dependent multiple exciton generation efficiency in PbS, PbSe, and PbS x Se 1- x alloyed quantum dots. Nano Lett. 13 , 3078– 3085 (2013)..

Beard, M. C. et al. Third generation photovoltaics based on multiple exciton generation in quantum confined semiconductors. Acc. Chem. Res. 46 , 1252–1260 (2013)..

Nozik, A. J. et al. Semiconductor quantum dots and quantum dot arrays and applications of multiple exciton generation to third-generation photovoltaic solar cells. Chem. Rev. 110 , 6873–6890 (2010)..

Trinh, M. T. et al. Direct generation of multiple excitons in adjacent silicon nanocrystals revealed by induced absorption. Nat. Photonics 6 , 316–321 (2012)..

Saeed, S. et al. Carrier multiplication in germanium nanocrystals. Light Sci. Appl. 4 , e251 (2015)..

Zheng, W. H., Bonn, M. & Wang, H. I. Photoconductivity multiplication in semiconducting few-layer MoTe 2 . Nano Lett. 20 , 5807–5813 (2020)..

Kim, J. H. et al. Carrier multiplication in van der Waals layered transition metal dichalcogenides. Nat. Commun. 10 , 5488 (2019)..

Chen, Y. F. et al. Multiple exciton generation in tin–lead halide perovskite nanocrystals for photocurrent quantum efficiency enhancement. Nat. Photonics 16 , 485–490 (2022)..

Schaibley, J. R. et al. Valleytronics in 2D materials. Nat. Rev. Mater. 1 , 16055 (2016)..

Sierra, J. F. et al. Van der Waals heterostructures for spintronics and opto-spintronics. Nat. Nanotechnol. 16 , 856–868 (2021)..

Liu, X. L. & Hersam, M. C. 2D materials for quantum information science. Nat. Rev. Mater. 4 , 669–684 (2019)..

Jiang, Y. et al. Interlayer exciton formation, relaxation, and transport in TMD van der Waals heterostructures. Light Sci. Appl. 10 , 72 (2021)..

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

Bian, A. et al. Dynamics of charge-transfer excitons in a transition metal dichalcogenide heterostructure. Nanoscale 12 , 8485–8492 (2020)..

Ceballos, F. et al. Ultrafast charge separation and indirect exciton formation in a MoS 2 –MoSe 2 van der Waals heterostructure. ACS Nano 8 , 12717–12724 (2014)..

Ceballos, F. et al. Probing charge transfer excitons in a MoSe 2 –WS 2 van der Waals heterostructure. Nanoscale 7 , 17523–17528 (2015)..

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

Joe, A. Y. et al. Controlled interlayer exciton ionization in an electrostatic trap in atomically thin heterostructures. Nat. Commun. 15 , 6743 (2024)..

Kumar, N. et al. Second harmonic microscopy of monolayer MoS 2 . Phys. Rev. B 87 , 161403 (2013)..

Malard, L. M. et al. Observation of intense second harmonic generation from MoS 2 atomic crystals. Phys. Rev. B 87 , 201401 (2013)..

Li, Y. L. et al. Probing symmetry properties of few-layer MoS 2 and h-BN by optical second-harmonic generation. Nano Lett. 13 , 3329–3333 (2013)..

Karni, O. et al. Infrared interlayer exciton emission in MoS 2 /WSe 2 heterostructures. Phys. Rev. Lett. 123 , 247402 (2019)..

Kunstmann, J. et al. Momentum-space indirect interlayer excitons in transition-metal dichalcogenide van der Waals heterostructures. Nat. Phys. 14 , 801–805 (2018)..

Chiu, M. H. et al. Determination of band alignment in the single-layer MoS 2 /WSe 2 heterojunction. Nat. Commun. 6 , 7666 (2015)..

Choi, J. et al. Twist angle-dependent interlayer exciton lifetimes in van der Waals heterostructures. Phys. Rev. Lett. 126 , 047401 (2021)..

Hong, X. P. et al. Ultrafast charge transfer in atomically thin MoS 2 /WS 2 heterostructures. Nat. Nanotechnol. 9 , 682–686 (2014)..

Ceballos, F. et al. Exciton formation in monolayer transition metal dichalcogenides. Nanoscale 8 , 11681–11688 (2016). .

Steinleitner, P. et al. Direct observation of ultrafast exciton formation in a monolayer of WSe 2 . Nano Lett. 17 , 1455–1460 (2017)..

Yuan, L. et al. Twist-angle-dependent interlayer exciton diffusion in WS 2 –WSe 2 heterobilayers. Nat. Mater. 19 , 617–623 (2020)..

Yuan, Y. J. et al. Probing the twist-controlled interlayer coupling in artificially stacked transition metal dichalcogenide bilayers by second-harmonic generation. ACS Nano 17 , 17897–17907 (2023)..

Li, Y. L. et al. Biexciton Auger recombination in mono-dispersed, quantum-confined CsPbBr 3 perovskite nanocrystals obeys universal volume-scaling. Nano Res. 12 , 619–623 (2019)..

Meng, J. et al. Tailoring auger recombination dynamics in CsPbI 3 perovskite nanocrystals via transition metal doping. Nano Lett. 24 , 8386–8393 (2024)..

Li, M. J. et al. Low threshold and efficient multiple exciton generation in halide perovskite nanocrystals. Nat. Commun. 9 , 4197 (2018)..

Christodoulou, S. et al. Single-exciton gain and stimulated emission across the infrared telecom band from robust heavily doped PbS colloidal quantum dots. Nano Lett. 20 , 5909–5915 (2020)..

Yang, W. X. et al. Surface passivation extends single and biexciton lifetimes of InP quantum dots. Chem. Sci. 11 , 5779–5789 (2020)..

Zhou, Q. H. et al. Highly efficient multiple exciton generation and harvesting in few-layer black phosphorus and heterostructure. Nano Lett. 20 , 8212–8219 (2020)..

Al-Otaify, A. et al. Multiple exciton generation and ultrafast exciton dynamics in HgTe colloidal quantum dots. Phys. Chem. Chem. Phys. 15 , 16864–16873 (2013)..

Ghosh, G. et al. Carrier multiplication and photoexcited many-body states in solution-processed 2H-MoSe 2 . ACS Nano 19 , 10347–10358 (2025)..

Karmakar, R. et al. Multiple carrier generation at an exceptionally low energy threshold. Phys. Rev. Lett. 134 , 026903 (2025)..

Beard, M. C. et al. Comparing multiple exciton generation in quantum dots to impact ionization in bulk semiconductors: implications for enhancement of solar energy conversion. Nano Lett. 10 , 3019–3027 (2010)..

Zhu, Y. H. et al. The twist angle has weak influence on charge separation and strong influence on recombination in the MoS 2 /WS 2 bilayer: ab initio quantum dynamics. J. Mater. Chem. A 10 , 8324–8333 (2022)..

Liu, F., Li, Q. Y. & Zhu, X. Y. Direct determination of momentum-resolved electron transfer in the photoexcited van der Waals heterobilayer WS 2 /MoS 2 . Phys. Rev. B 101 , 201405 (2020)..

Ji, Z. H. et al. Robust stacking-independent ultrafast charge transfer in MoS 2 /WS 2 bilayers. ACS Nano 11 , 12020–12026 (2017)..

Zhu, H. M. et al. Interfacial charge transfer circumventing momentum mismatch at two-dimensional van der Waals heterojunctions. Nano Lett. 17 , 3591–3598 (2017)..

Fang, S. A. et al. Electronic structure theory of strained two-dimensional materials with hexagonal symmetry. Phys. Rev. B 98 , 075106 (2018)..

Isler, M. Phonon-assisted impact ionization of electrons in In 0.53 Ga 0.47 As. Phys. Rev. B 63 , 115209 (2001)..

Eshet, H. et al. Theory of highly efficient multiexciton generation in type-Ⅱ nanorods. Nat. Commun. 7 , 13178 (2016)..

Florian, M. et al. The dielectric impact of layer distances on exciton and trion binding energies in van der Waals heterostructures. Nano Lett. 18 , 2725–2732 (2018)..

Sun, X. Q. et al. Enhanced interactions of interlayer excitons in free-standing heterobilayers. Nature 610 , 478–484 (2022)..

Sie, E. J. et al. Observation of exciton redshift–blueshift crossover in monolayer WS 2 . Nano Lett. 17 , 4210–4216 (2017)..

Naik, S. et al. Twister: construction and structural relaxation of commensurate moiré superlattices. Comput. Phys. Commun. 271 , 108184 (2022)..

Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77 , 3865–3868 (1996)..

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