Electrical tuning of moiré excitons in MoSe${}_2$ bilayers

Abstract

Recent advances in the field of vertically stacked 2D materials have revealed a rich exciton landscape. In particular, it has been demonstrated that out-of-plane electrical fields can be used to tune the spectral position of spatially separated interlayer excitons. Other studies have shown that there is a strong hybridization of exciton states, resulting from the mixing of electronic states in both layers. However, the connection between the twist-angle dependent hybridization and field-induced energy shifts has remained in the dark. Here, we investigate on a microscopic footing the interplay of electrical and twist-angle tuning of moiré excitons in MoSe${}_2$ homobilayers. We reveal distinct energy regions in PL spectra that are clearly dominated by either intralayer or interlayer excitons, or even dark excitons. Consequently, we predict twist-angle-dependent critical electrical fields at which the material is being transformed from a direct into an indirect semiconductor. Our work provides new microscopic insights into experimentally accessible knobs to significantly tune the moiré exciton physics in atomically thin nanomaterials.

12 pages, 5 figures

References in corpus (13)

• Observation of Long-Lived Interlayer Excitons in Monolayer MoSe2-WSe2 Heterostructures
• Tightly bound excitons in monolayer WSe2
• Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
• Moiré excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices
• Ultrafast transition between exciton phases in van der Waals heterostructures
• Dark excitons in transition metal dichalcogenides
• Molecular-beam epitaxy of monolayer and bilayer WSe2: A scanning tunneling microscopy/spectroscopy study and deduction of exciton binding energy
• Hybridized intervalley moiré excitons and flat bands in twisted WSe${}_2$ bilayers
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Exciton landscape in van der Waals heterostructures
• Twist Angle Tuning of Moiré Exciton Polaritons in van der Waals Heterostructures
• Spatially indirect intervalley excitons in bilayer WSe2
• The moiré potential in twisted transition metal dichalcogenide bilayers

Cited by in corpus (15)

• Electrical control of hybrid exciton transport in a van der Waals heterostructure
• Highly Tunable Ground and Excited State Excitonic Dipoles in Multilayer 2H-MoSe${}_2$
• Nonlinear optics in 2D materials: from classical to quantum
• Electrically tunable dipolar interactions between layer-hybridized excitons
• Impact of atomic reconstruction on optical spectra of twisted TMD homobilayers
• Quadrupolar Excitons in MoSe${}_2$ Bilayers
• Confined-state physics and signs of fermionization of moiré excitons in WSe${}_2$/MoSe${}_2$ heterobilayers
• Analogy and dissimilarity of excitons in monolayer and bilayer of MoSe${}_2$
• Direct visualization of hybrid excitons in van der Waals heterostructures
• Electrically tunable layer-hybridized trions in doped WSe${}_2$ bilayers
• Interlayer exciton polaritons in homobilayers of transition metal dichalcogenides
• Quadrupolar and Dipolar Excitons in Bilayer 2$H$-MoSe${}_2$
• Impact of charge transfer excitons on unidirectional exciton transport in lateral TMD heterostructures
• Polarization and charge-separation of moiré excitons in van der Waals heterostructures
• Two dimensional semiconductors: optical and electronic properties