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The authors observe the signatures of quadrupolar excitons in a WSe₂-WS₂-WSe₂ trilayer moiré superlattice, originating from the hybridization of the WSe₂ valence moiré flatbands. They further use electrostatic gating to reveal a hybridized interlayer Mott insulator state, with holes shared between the two WSe₂ layers but laterally confined in moiré superlattices.

The study shows that exciton diffusivity in semiconducting moiré superlattices can be strongly modulated by correlated electrons, revealing intriguing interactions and ushering in avenues for quantum optoelectronic technologies.

Heterobilayers of transition metal dichalcogenides host moiré superlattices that give rise to strong electron interactions. Here, the authors study the photoluminescence from interlayer excitons in a WS₂/WSe₂ heterobilayer to reveal the onset of various correlated insulating states.

The ultrafast carrier dynamics across the van der Waals interface of transition metal dichalcogenide heterostructures govern the formation and funnelling of excitons. Here, the authors demonstrate a reversible switch from exciton dissociation to exciton funnelling in a MoSe₂/WS₂ heterostructure, which manifests itself as a photoluminescence quenching-to-enhancement transition.

Owing to strong Coulomb interactions, atomically thin transition metal dichalcogenides host strongly bound excitonic complexes. Here, the authors report charge-neutral biexciton and negatively charged trion-exciton complexes in hBN encapsulated monolayer WSe₂ by employing low-temperature photoluminescence spectroscopy.

A dual-gated moiré superlattice device made of trilayer WSe₂/WS₂/WSe₂ enables controlling quadrupolar excitons by driving quadrupolar-to-dipolar exciton transitions via tuning the excitation intensity and doping.

A time-dependent study of the effective temperature of carriers in impurity-free graphene now indicates that a disorder-assisted mechanism is responsible for cooling hot electrons. Observation of this so-called supercollision contradicts the idea that electron–phonon interactions dominate cooling.

Van der Waals heterostructures consisting of a single MoS₂ monolayer and a single WSe₂ monolayer can be used to form p–n junctions.

Transition metal dichalcogenides are attracting widespread attention for their appealing optoelectronic properties. Using a combination of numerical and experimental techniques, the exciton binding energy is now determined for MoSe₂ on graphene.

The charge transfer between two layers of different two-dimensional materials occurs at a much faster speed than expected, holding promise for efficient optoelectronic devices.

VS₂ is a promising cathode material for lithium-ion batteries, but is susceptible to Peierls distortion during (de)lithiation. Here the authors show that VS₂ cathodes can be stabilized by conformally coating them with a nanoscale TiS₂ protective layer, leading to impressive electrochemical performance.

Interactions between excitons and correlated electrons can lead to the formation of interesting states. Now, evidence suggests that these interactions can give rise to a Mott insulator of excitons.

An out-of-plane magnetic field is expected to strongly modify exciton-phonon interactions in atomically thin transitional metal dichalcogenides. Here, the authors show that the phonon-exciton interaction in monolayer WSe₂ lifts the inter-Landau-level transition selection rules for dark trions.

A Gd@C₈₂ molecule shows electric polarization switching behaviour under a gate bias voltage, thus demonstrating a single-molecule electret device.

The moiré lattice of trilayer WSe₂ and monolayer WS₂ host interlayer excitons localized at different moiré sites. Using an electric field, the authors tune the superposition between two moiré sites via hybridization with intralayer excitons in WSe₂.

Twisted heterostructures of transition metal dichalcogenides host the so-called moiré excitons, or intralayer excitons modified by the moiré potential. Here the authors show tunability of the moiré excitons and the coexisting correlated electronic states in WSe₂/WS₂ superlattices with varying WSe₂ layer thickness

The long lifetime and spin properties of dark excitons in atomically thin transition metal dichalcogenides offer opportunities to explore light-matter interactions beyond electric dipole transitions. Here, the authors demonstrate that the coupling of the dark exciton and an optically silent chiral phonon enables the intrinsic photoluminescence of the dark-exciton replica in monolayer WSe₂

The enhanced Coulomb interaction in two dimensions leads to not only tightly bound excitons but also many-particle excitonic complexes: excitons interacting with other quasiparticles, which results in improved and even new exciton properties with better controls. Here, we summarize studies of excitonic complexes in monolayer transition metal dichalcogenides and their moiré heterojunctions, envisioning how to utilize them for exploring quantum many-body physics.

Stacking monolayer WS₂ on top of bilayer WSe₂ creates conditions where electrons and holes can coexist in the structure. Their Coulomb interaction allows them to form bound pairs and hence an excitonic insulator state.

Twisted bilayers of WS₂ and WSe₂ have correlated states that correspond to real-space ordering of the electrons on a length scale much longer than the moiré pattern.