Tightly bound excitons in monolayer WSe2

Abstract

Exciton binding energy and excited states in monolayers of tungsten diselenide (WSe2) are investigated using the combined linear absorption and two-photon photoluminescence excitation spectroscopy. The exciton binding energy is determined to be 0.37eV, which is about an order of magnitude larger than that in III-V semiconductor quantum wells and renders the exciton excited states observable even at room temperature. The exciton excitation spectrum with both experimentally determined one- and two-photon active states is distinct from the simple two-dimensional (2D) hydrogenic model. This result reveals significantly reduced and nonlocal dielectric screening of Coulomb interactions in 2D semiconductors. The observed large exciton binding energy will also have a significant impact on next-generation photonics and optoelectronics applications based on 2D atomic crystals.

19 pages, 4 figures, to appear in PRL

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Cited by in corpus (87)

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• Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2
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• Non-linear Optical Spectroscopy of Excited Exciton States for Efficient Valley Coherence Generation in WSe2 Monolayers
• Electrical Control of Second-Harmonic Generation in a WSe2 Monolayer Transistor
• Valley Splitting and Polarization by the Zeeman Effect in Monolayer MoSe2
• Probing excitonic states in ultraclean suspended two-dimensional semiconductors by photocurrent spectroscopy
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• Measurement of high exciton binding energy in the monolayer transition-metal dichalcogenides WS2 and WSe2
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• Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers
• Trion induced negative photoconductivity in monolayer MoS2
• Probing the influence of dielectric environment on excitons in monolayer WSe2: Insight from high magnetic fields
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• Valley Phonons and Exciton Complexes in a Monolayer Semiconductor
• Phonon Sidebands in Transition Metal Dichalcogenides
• Polarization and time-resolved photoluminescence spectroscopy of excitons in MoSe2 monolayers
• Exciton and trion dynamics in atomically thin MoSe2 and WSe2: effect of localization
• Emerging Photoluminescence from the Dark-Exciton Phonon Replica in Monolayer WSe2
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• Optical response of monolayer, few-layer and bulk tungsten disulfide
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• Optical spectroscopy of excited exciton states in MoS2 monolayers in van der Waals heterostructures
• All-optical band engineering of gapped Dirac materials
• Engineering of Neutral Excitons and Exciton Complexes in Transition Metal Dichalcogenide Monolayers through External Dielectric Screening
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• Hybridized intervalley moiré excitons and flat bands in twisted WSe${}_2$ bilayers
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• Influence of the effective layer thickness on the groundstate and excitonic properties of transition-metal dichalcogenide systems
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• Integrated Single Photon Emitters
• Exciton binding energies and luminescence of phosphorene under pressure
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• Trion Species-Resolved Quantum Beats in MoSe2
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• Valley-Polarized Exciton Dynamics in Exfoliated Monolayer WSe${}_2$
• Optical selection rules for excitonic Rydberg series in the massive Dirac cones of hexagonal 2D materials
• Fundamental exciton linewidth broadening in monolayer transition metal dichalcogenides
• Strong Single- and Two-Photon Luminescence Enhancement by Nonradiative Energy Transfer across Layered Heterostructure
• Gate-modulated conductance of few-layer WSe_2 field-effect transistors in the subgap regime: Schottky barrier transistor and subgap impurity states
• Population pulsation resonances of excitons in monolayer MoSe2 with sub 1 μeV linewidth
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