Room-Temperature, Strong Emission of Momentum-Forbidden Interlayer Excitons in Nanocavity-Coupled Twisted van der Waals Heterostructures

Bin Feng; Shixuan Zhao; Ilya Razdolski; Feihong Liu; Zhiwei Peng; Yaorong Wang; Zhedong Zhang; Zhenhua Ni; Jianbin Xu; Dangyuan Lei

doi:10.1021/acs.nanolett.4c05647

Room-Temperature, Strong Emission of Momentum-Forbidden Interlayer Excitons in Nanocavity-Coupled Twisted van der Waals Heterostructures

Bin Feng, Shixuan Zhao, Ilya Razdolski, Feihong Liu, Zhiwei Peng, Yaorong Wang, Zhedong Zhang, Zhenhua Ni, Jianbin Xu, Dangyuan Lei^*

^*Corresponding author for this work

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

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Abstract

The emission efficiency of interlayer excitons (IEs) in twisted 2D heterostructures has long suffered from momentum mismatch, limiting their applications in ultracompact excitonic devices. Here, we report strong room-temperature emission of momentum-forbidden IE in 30°-twisted MoS₂/WS₂ heterobilayers. Utilizing a plasmonic nanocavity, the Purcell effect boosts the IE emission intensity in the cavity by over 2 orders of magnitude. We further study the interplay of this Purcell enhancement and phonon assistance in 30°- and 0°-twisted heterostructures. Temperature-dependent and time-resolved spectroscopy reveal that the IE enhancement in 30°-twisted cases involves competition between IEs and intralayer excitonic emission, which is remarkably distinct from the 0°-twisted cases. We propose a comprehensive exciton decay model capturing the features of the phonon-assisted momentum compensation and the Purcell enhancement of the IE emission, showing consistency with the experimental measurements. Our results enrich the understanding of the nanocavity-assisted light-matter interaction for momentum-indirect excitonic transitions. © 2025 American Chemical Society.

Original language	English
Pages (from-to)	1609–1616
Journal	Nano Letters
Volume	25
Issue number	4
Online published	8 Jan 2025
DOIs	https://doi.org/10.1021/acs.nanolett.4c05647
Publication status	Published - 29 Jan 2025

Funding

We acknowledge the financial support from the Research Grants Council of Hong Kong through a General Research Fund Grant (11309623) and an Area of Excellence Grant (AoE/P-701/20). B.F. appreciates Tsz Wing Lo for his fruitful discussions.

Research Keywords

heterostructure
interlayer exciton
momentum mismatch
Purcell effect
twist angle

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This full text is made available under CC-BY 4.0. https://creativecommons.org/licenses/by/4.0/

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title = "Room-Temperature, Strong Emission of Momentum-Forbidden Interlayer Excitons in Nanocavity-Coupled Twisted van der Waals Heterostructures",

abstract = "The emission efficiency of interlayer excitons (IEs) in twisted 2D heterostructures has long suffered from momentum mismatch, limiting their applications in ultracompact excitonic devices. Here, we report strong room-temperature emission of momentum-forbidden IE in 30°-twisted MoS2/WS2 heterobilayers. Utilizing a plasmonic nanocavity, the Purcell effect boosts the IE emission intensity in the cavity by over 2 orders of magnitude. We further study the interplay of this Purcell enhancement and phonon assistance in 30°- and 0°-twisted heterostructures. Temperature-dependent and time-resolved spectroscopy reveal that the IE enhancement in 30°-twisted cases involves competition between IEs and intralayer excitonic emission, which is remarkably distinct from the 0°-twisted cases. We propose a comprehensive exciton decay model capturing the features of the phonon-assisted momentum compensation and the Purcell enhancement of the IE emission, showing consistency with the experimental measurements. Our results enrich the understanding of the nanocavity-assisted light-matter interaction for momentum-indirect excitonic transitions. {\textcopyright} 2025 American Chemical Society.",

keywords = "heterostructure, interlayer exciton, momentum mismatch, Purcell effect, twist angle",

author = "Bin Feng and Shixuan Zhao and Ilya Razdolski and Feihong Liu and Zhiwei Peng and Yaorong Wang and Zhedong Zhang and Zhenhua Ni and Jianbin Xu and Dangyuan Lei",

year = "2025",

month = jan,

day = "29",

doi = "10.1021/acs.nanolett.4c05647",

language = "English",

volume = "25",

pages = "1609–1616",

journal = "Nano Letters",

issn = "1530-6984",

publisher = "American Chemical Society",

number = "4",

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TY - JOUR

T1 - Room-Temperature, Strong Emission of Momentum-Forbidden Interlayer Excitons in Nanocavity-Coupled Twisted van der Waals Heterostructures

AU - Feng, Bin

AU - Zhao, Shixuan

AU - Razdolski, Ilya

AU - Liu, Feihong

AU - Peng, Zhiwei

AU - Wang, Yaorong

AU - Zhang, Zhedong

AU - Ni, Zhenhua

AU - Xu, Jianbin

AU - Lei, Dangyuan

PY - 2025/1/29

Y1 - 2025/1/29

N2 - The emission efficiency of interlayer excitons (IEs) in twisted 2D heterostructures has long suffered from momentum mismatch, limiting their applications in ultracompact excitonic devices. Here, we report strong room-temperature emission of momentum-forbidden IE in 30°-twisted MoS2/WS2 heterobilayers. Utilizing a plasmonic nanocavity, the Purcell effect boosts the IE emission intensity in the cavity by over 2 orders of magnitude. We further study the interplay of this Purcell enhancement and phonon assistance in 30°- and 0°-twisted heterostructures. Temperature-dependent and time-resolved spectroscopy reveal that the IE enhancement in 30°-twisted cases involves competition between IEs and intralayer excitonic emission, which is remarkably distinct from the 0°-twisted cases. We propose a comprehensive exciton decay model capturing the features of the phonon-assisted momentum compensation and the Purcell enhancement of the IE emission, showing consistency with the experimental measurements. Our results enrich the understanding of the nanocavity-assisted light-matter interaction for momentum-indirect excitonic transitions. © 2025 American Chemical Society.

AB - The emission efficiency of interlayer excitons (IEs) in twisted 2D heterostructures has long suffered from momentum mismatch, limiting their applications in ultracompact excitonic devices. Here, we report strong room-temperature emission of momentum-forbidden IE in 30°-twisted MoS2/WS2 heterobilayers. Utilizing a plasmonic nanocavity, the Purcell effect boosts the IE emission intensity in the cavity by over 2 orders of magnitude. We further study the interplay of this Purcell enhancement and phonon assistance in 30°- and 0°-twisted heterostructures. Temperature-dependent and time-resolved spectroscopy reveal that the IE enhancement in 30°-twisted cases involves competition between IEs and intralayer excitonic emission, which is remarkably distinct from the 0°-twisted cases. We propose a comprehensive exciton decay model capturing the features of the phonon-assisted momentum compensation and the Purcell enhancement of the IE emission, showing consistency with the experimental measurements. Our results enrich the understanding of the nanocavity-assisted light-matter interaction for momentum-indirect excitonic transitions. © 2025 American Chemical Society.

KW - heterostructure

KW - interlayer exciton

KW - momentum mismatch

KW - Purcell effect

KW - twist angle

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U2 - 10.1021/acs.nanolett.4c05647

DO - 10.1021/acs.nanolett.4c05647

M3 - RGC 21 - Publication in refereed journal

SN - 1530-6984

VL - 25

SP - 1609

EP - 1616

JO - Nano Letters

JF - Nano Letters

IS - 4

ER -

Room-Temperature, Strong Emission of Momentum-Forbidden Interlayer Excitons in Nanocavity-Coupled Twisted van der Waals Heterostructures

Abstract

Funding

Research Keywords

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GRF: Spectrally and Spatially Selective Brightening of Interlayer Excitons in TMDC vdW Heterostructures with Large-quality-factor, Small-mode-volume Magnetic Plasmon Resonance

AoE(UGC)-ExtU-Lead: 2D Materials Research: Fundamentals Towards Emerging Technologies

Cite this

Room-Temperature, Strong Emission of Momentum-Forbidden Interlayer Excitons in Nanocavity-Coupled Twisted van der Waals Heterostructures

Abstract

Funding

Research Keywords

Publisher's Copyright Statement

Access Output

Other Access Options

Permanent Link

Other Files and Links

Fingerprint

Projects

GRF: Spectrally and Spatially Selective Brightening of Interlayer Excitons in TMDC vdW Heterostructures with Large-quality-factor, Small-mode-volume Magnetic Plasmon Resonance

AoE(UGC)-ExtU-Lead: 2D Materials Research: Fundamentals Towards Emerging Technologies

Cite this