Electrical tuning of layer-polarized exciton gases in WSe2 bilayers

Abstract

Van der Waals heterostructures formed by stacking two-dimensional atomic crystals are a unique platform for exploring new phenomena and functionalities. Interlayer excitons, bound states of spatially separated electron-hole pairs in van der Waals heterostructures, have demonstrated potential for rich valley physics and optoelectronics applications, and been proposed to facilitate high-temperature superfluidity. Here, we demonstrate highly tunable layer-polarized excitons by an out-of-plane electric field in homo-bilayers of transition metal dichalcogenides. Continuous tuning from negative to positive layer polarity has been achieved, which is not possible in hetero-bilayers due to the presence of large built-in interfacial electric fields. A large linear field-induced redshift up to ~ 100 meV has been observed in the exciton resonance energy. The Stark effect is accompanied by an enhancement of the exciton recombination lifetime by more than two orders of magnitude to > 20 ns. The long recombination lifetime has allowed the creation of a layer-polarized exciton gas with density as large as 1.2*10^11 cm^-2 by moderate continuous-wave optical pumping. Our results have paved the way for realization of degenerate exciton gases in atomically thin semiconductors.

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• Atomically thin MoS2: A new direct-gap semiconductor
• Van der Waals heterostructures
• 2D materials and van der Waals heterostructures
• Atomically thin p-n junctions with van der Waals heterointerfaces
• Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
• Evolution of Electronic Structure in Atomically Thin Sheets of WS2 and WSe2
• Observation of Long-Lived Interlayer Excitons in Monolayer MoSe2-WSe2 Heterostructures
• Light-emitting diodes by bandstructure engineering in van der Waals heterostructures
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• Electrical Tuning of Valley Magnetic Moment via Symmetry Control
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Electrical control of the valley Hall effect in bilayer MoS2 transistors
• Topological Exciton Bands in Moiré Heterojunctions
• Spin-Layer Locking Effects in Optical Orientation of Exciton Spin in Bilayer WSe2
• Anomalous light cones and valley optical selection rules of interlayer excitons in twisted heterobilayers
• Valley-spin polarized Landau levels in a monolayer semiconductor
• Probing the spin-polarized electronic band structure in monolayer transition metal dichalcogenides by optical spectroscopy
• Stark effect spectroscopy of mono- and few-layer MoS${}_2$
• Observation of Ultralong Valley Lifetime in WSe2/MoS2 Heterostructures

Cited by in corpus (56)

• Moiré Excitons in Van der Waals Heterostructures
• Controlling magnetism in 2D CrI3 by electrostatic doping
• Dipolar interactions between field-tuneable, localized emitters in van der Waals heterostructures
• Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe${}_2$/MoSe${}_2$ bilayers
• Electrically tunable valley dynamics in twisted WSe${}_2$/WSe${}_2$ bilayers
• Gate-tunable spin waves in antiferromagnetic atomic bilayers
• Interlayer excitons in bilayer MoS2 with strong oscillator strength up to room temperature
• Valley-Layer Coupling: A New Design Principle for Valleytronics
• Giant Stark splitting of an exciton in bilayer MoS${}_2$
• Interlayer coupling and gate-tunable excitons in transition metal dichalcogenide heterostructures
• Correlated insulator of excitons in WSe2/WS2 moiré superlattices
• Generating extreme electric fields in 2D materials by dual ionic gating
• Electrical control of hybrid exciton transport in a van der Waals heterostructure
• Localized bright luminescence of indirect excitons and trions in MoSe${}_2$/WSe${}_2$ van der Waals heterostructure
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Observation of Inter-layer Excitons in MoSe2 Single Crystals
• Long-range transport of 2D excitons with acoustic waves
• Dipolar and magnetic properties of strongly absorbing hybrid interlayer excitons in pristine bilayer MoS${}_2$
• Moiré-trapped interlayer trions in a charge-tunable WSe${}_2$/MoSe${}_2$ heterobilayer
• Exciton density waves in Coulomb-coupled dual moiré lattices
• Electrically Controlled Two-Dimensional Electron-Hole Fluids
• Electrical tuning of moiré excitons in MoSe${}_2$ bilayers
• Stacking-dependent exciton multiplicity in WSe${}_2$ bilayers
• Suppressed out-of-plane polarizability of free excitons in monolayer WSe${}_2$
• Spatially indirect intervalley excitons in bilayer WSe2
• Highly Tunable Ground and Excited State Excitonic Dipoles in Multilayer 2H-MoSe${}_2$
• Nonlinear optics in 2D materials: from classical to quantum
• Anomalous Stark Shift of Excitonic Complexes in Monolayer Semiconductor
• Ultrafast photocurrents in MoSe${}_2$ probed by terahertz spectroscopy
• Field-induced hybridization of moiré excitons in MoSe${}_2$/WS${}_2$ heterobilayers
• Leaky exciton condensates in transition metal dichalcogenide moiré bilayers
• Tuning of impurity-bound interlayer complexes in a van der Waals heterobilayer
• Excitonic Absorption Signatures of Twisted Bilayer WSe${}_2$ by Electron Energy-Loss Spectroscopy
• Electrically tunable dipolar interactions between layer-hybridized excitons
• Ultrafast pseudospin quantum beats in multilayer WSe${}_2$ and MoSe${}_2$
• Crossover from weakly indirect to direct excitons in atomically thin films of InSe
• Tuning exciton complexes in twisted bilayer WSe2 at intermediate misorientation
• Impact of atomic reconstruction on optical spectra of twisted TMD homobilayers
• High-mobility indirect excitons in wide single quantum well
• Quadrupolar Excitons in MoSe${}_2$ Bilayers
• Electrically tunable layer-hybridized trions in doped WSe${}_2$ bilayers
• Optical readout of the chemical potential of two-dimensional electrons
• Terahertz field effect in a two-dimensional semiconductor MoS2
• Electrical Control of Two-Dimensional Electron-Hole Fluids in the Quantum Hall Regime
• Long-distance decay-less spin transport in indirect excitons in a van der Waals heterostructure
• Quantum Oscillation in Excitonic Insulating Electron-Hole Bilayer
• Electrically controllable router of interlayer excitons
• Coupled spin-charge dynamics in magnetic van der Waals heterostructures
• Electric-field-tunable intervalley excitons and phonon replicas in bilayer WSe${}_2$
• Exciton fractional Chern insulators in moiré heterostructures
• Charged bosons made of fermions in a solid state system without Cooper pairing
• Brightening interlayer excitons by electric-field-driven hole transfer in bilayer WSe2
• Emergence of non-uniform strain induced exciton species in homo- and heterobilayer transition metal dichalcogenides
• Observation of the Interlayer Exciton Gases in WSe${}_2$ -p: WSe${}_2$ Heterostructures
• Interlayer Coupling Effect in van der Waals Heterostructures of Transition Metal Dichalcogenides
• Tunable phononic coupling in excitonic quantum emitters