Exciton landscape in van der Waals heterostructures

Abstract

van der Waals heterostructures consisting of vertically stacked transition-metal dichalcogenides (TMDs) exhibit a rich landscape of bright and dark intra- and interlayer excitons. In spite of a growing literature in this field of research, the type of excitons dominating optical spectra in different van der Waals heterostructures has not yet been well established. The spectral position of exciton states depends strongly on the strength of hybridization and energy renormalization due to the periodic moiré potential. Combining exciton density-matrix formalism and density-functional theory, we shed light on the exciton landscape in TMD homo- and heterobilayers at different stackings. This allows us to identify on a microscopic footing the energetically lowest-lying exciton state for each material and stacking. Furthermore, we disentangle the contribution of hybridization and layer polarization-induced alignment shifts of dark and bright excitons in photoluminescence spectra. By revealing the exciton landscape in van der Waals heterostructures, our work provides the basis for further studies of the optical, dynamical, and transport properties of this technologically promising class of nanomaterials.

15 pages, 9 figures

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Cited by in corpus (28)

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• Microscopic origin of anomalous interlayer exciton transport in van der Waals heterostructures
• Highly Tunable Ground and Excited State Excitonic Dipoles in Multilayer 2H-MoSe${}_2$
• Twist-dependent intra- and interlayer excitons in moire MoSe2 homobilayers
• Probing correlations in the exciton landscape of a moiré heterostructure
• Ultrafast phonon-driven charge transfer in van der Waals heterostructures
• Interlayer exciton valley polarization dynamics in large magnetic fields
• Bright dipolar excitons in twisted black phosphorus homostructures
• Twist angle dependent interlayer transfer of valley polarization from excitons to free charge carriers in WSe${}_2$/MoSe${}_2$ heterobilayers
• Leaky exciton condensates in transition metal dichalcogenide moiré bilayers
• Electrically tunable dipolar interactions between layer-hybridized excitons
• Exciton Superposition across Moiré States in a Semiconducting Moiré Superlattice
• Impact of atomic reconstruction on optical spectra of twisted TMD homobilayers
• Ultrafast nano-imaging of dark excitons
• Quadrupolar Excitons in MoSe${}_2$ Bilayers
• Spatiotemporal dynamics of moiré excitons in van der Waals heterostructures
• Probing excitons with time-resolved momentum microscopy
• Direct visualization of hybrid excitons in van der Waals heterostructures
• Electrically tunable layer-hybridized trions in doped WSe${}_2$ bilayers
• Excitonic thermalization bottleneck in twisted TMD heterostructures
• Interlayer exciton polaritons in homobilayers of transition metal dichalcogenides
• Electrical reversal of the sign for magnon thermal Hall coefficient in a van der Waals bilayer antiferromagnet
• Polarization and charge-separation of moiré excitons in van der Waals heterostructures
• Photoemission orbital tomography for excitons in organic molecules
• Two dimensional semiconductors: optical and electronic properties
• Stability of Wigner crystals and Mott insulators in twisted moiré structures
• Intersubband electric dipole spin resonance in transition metal dichalcogenide heterobilayers