Biexciton
View article: Extremely efficient internal exciton dissociation through edge states in layered 2D perovskites
Extremely efficient internal exciton dissociation through edge states in layered 2D perovskites Open
How perovskites have the edge Two-dimensional Ruddlesden-Popper perovskites form quantum wells by sandwiching inorganic-organic perovskite layers used in photovoltaic devices between organic layers. Blancon et al. show that if the perovski…
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Spectral and Dynamical Properties of Single Excitons, Biexcitons, and Trions in Cesium–Lead-Halide Perovskite Quantum Dots Open
Organic-inorganic lead-halide perovskites have been the subject of recent intense interest due to their unusually strong photovoltaic performance. A new addition to the perovskite family is all-inorganic Cs-Pb-halide perovskite nanocrystal…
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Exciton radiative lifetime in transition metal dichalcogenide monolayers Open
We have investigated the exciton dynamics in transition metal dichalcogenide\nmono-layers using time-resolved photoluminescence experiments performed with\noptimized time-resolution. For MoSe2 monolayers, we measure\n$\\tau_{rad}=1.8\\pm0.…
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Single Cesium Lead Halide Perovskite Nanocrystals at Low Temperature: Fast Single-Photon Emission, Reduced Blinking, and Exciton Fine Structure Open
Metal-halide semiconductors with perovskite crystal structure are attractive due to their facile solution processability, and have recently been harnessed very successfully for high-efficiency photovoltaics and bright light sources. Here, …
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Optical identification of sulfur vacancies: Bound excitons at the edges of monolayer tungsten disulfide Open
Bound exciton is a signature of sulfur vacancies, and thus, it can be used to investigate defects in atomically thin materials.
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Exciton Diffusion and Halo Effects in Monolayer Semiconductors Open
We directly monitor exciton propagation in freestanding and SiO_{2}-supported WS_{2} monolayers through spatially and time-resolved microphotoluminescence under ambient conditions. We find a highly nonlinear behavior with characteristic, q…
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Real-Time Observation of Exciton–Phonon Coupling Dynamics in Self-Assembled Hybrid Perovskite Quantum Wells Open
Self-assembled hybrid perovskite quantum wells have attracted attention due to their tunable emission properties, ease of fabrication and device integration. However, the dynamics of excitons in these materials, especially how they couple …
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Probing the Influence of Dielectric Environment on Excitons in Monolayer WSe<sub>2</sub>: Insight from High Magnetic Fields Open
Excitons in atomically thin semiconductors necessarily lie close to a surface, and therefore their properties are expected to be strongly influenced by the surrounding dielectric environment. However, systematic studies exploring this role…
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Highly energy-tunable quantum light from moiré-trapped excitons Open
Photon antibunching, a hallmark of quantum light, is observed from moiré-trapped interlayer excitons in a 2D heterobilayer.
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An exciton-polariton laser based on biologically produced fluorescent protein Open
Microcavities filled with biologically produced green fluorescent protein show polariton condensation at room temperature.
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Strain-Tunable GaAs Quantum Dot: A Nearly Dephasing-Free Source of Entangled Photon Pairs on Demand Open
We report on the observation of nearly maximally entangled photon pairs from semiconductor quantum dots, without resorting to postselection techniques. We use GaAs quantum dots integrated on a patterned piezoelectric actuator capable of su…
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Exciton Polarons in Two-Dimensional Hybrid Metal-Halide Perovskites Open
While polarons, charges bound to a lattice deformation induced by electron-phonon coupling, are primary photoexcitations in bulk metal-halide hybrid organic-inorganic perovskites (HOIPs), excitons, Coulomb-bound electron-hole pairs, are th…
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Unraveling exciton–phonon coupling in individual FAPbI3 nanocrystals emitting near-infrared single photons Open
Formamidinium lead iodide (FAPbI 3 ) exhibits the narrowest bandgap energy among lead halide perovskites, thus playing a pivotal role for the development of photovoltaics and near-infrared classical or quantum light sources. Here, we unvei…
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Dissociation of two-dimensional excitons in monolayer WSe<sub>2</sub> Open
Two-dimensional (2D) semiconducting materials are promising building blocks for optoelectronic applications, many of which require efficient dissociation of excitons into free electrons and holes. However, the strongly bound excitons arisi…
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Electroluminescence from multi-particle exciton complexes in transition metal dichalcogenide semiconductors Open
Light emission from higher-order correlated excitonic states has been recently reported in hBN-encapsulated monolayer WSe 2 and WS 2 upon optical excitation. These exciton complexes are found to be bound states of excitons residing in oppo…
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Observation of Exciton Redshift–Blueshift Crossover in Monolayer WS<sub>2</sub> Open
We report a rare atom-like interaction between excitons in monolayer WS2, measured using ultrafast absorption spectroscopy. At increasing excitation density, the exciton resonance energy exhibits a pronounced redshift followed by an anomal…
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Control of the Exciton Radiative Lifetime in van der Waals Heterostructures Open
Optical properties of atomically thin transition metal dichalcogenides are controlled by robust excitons characterized by a very large oscillator strengths. Encapsulation of monolayers such as MoSe_{2} in hexagonal boron nitride (hBN) yiel…
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Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder Open
With strongly bound and stable excitons at room temperature, single-layer, two-dimensional organic-inorganic hybrid perovskites are viable semiconductors for light-emitting quantum optoelectronics applications. In such a technological cont…
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Room-Temperature Micron-Scale Exciton Migration in a Stabilized Emissive Molecular Aggregate Open
We report 1.6 ± 1 μm exciton transport in self-assembled supramolecular light-harvesting nanotubes (LHNs) assembled from amphiphillic cyanine dyes. We stabilize LHNs in a sucrose glass matrix, greatly reducing light and oxidative damage an…
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Exciton-exciton interaction in transition-metal dichalcogenide monolayers Open
We study theoretically the Coulomb interaction between excitons in transition\nmetal dichalcogenide (TMD) monolayers. We calculate direct and exchange\ninteraction for both ground and excited states of excitons. The screening of\nthe Coulo…
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Sub–single-exciton lasing using charged quantum dots coupled to a distributed feedback cavity Open
Switching on quantum dot lasers The optical properties of quantum dots can be tailored with alterations to their size and composition. Developing quantum dots as low-threshold laser sources requires overcoming problems associated with carr…
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Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots Open
Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an improved synthesis method, have a great potential in life-science applications as well as in integrated quantum photonics and quantum information processing as si…
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Tuning Spin-Polarized Lifetime in Two-Dimensional Metal–Halide Perovskite through Exciton Binding Energy Open
Metal-halide perovskite semiconductors have attracted attention for opto-spintronic applications where the manipulation of charge and spin degrees of freedom have the potential to lower power consumption and achieve faster switching times …
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Strong coupling between excitons in transition metal dichalcogenides and optical bound states in the continuum Open
Being motivated by recent achievements in the rapidly developing fields of optical bound states in the continuum (BICs) and excitons in monolayers of transition metal dichalcogenides, we analyze strong coupling between BICs in Ta2O5 period…
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Diffusion quantum Monte Carlo study of excitonic complexes in two-dimensional transition-metal dichalcogenides Open
Excitonic effects play a particularly important role in the optoelectronic behavior of two-dimensional semiconductors. To facilitate the interpretation of experimental photoabsorption and photoluminescence spectra we provide (i) statistica…
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Coherent and Incoherent Coupling Dynamics between Neutral and Charged Excitons in Monolayer MoSe<sub>2</sub> Open
The optical properties of semiconducting transition metal dichalcogenides are dominated by both neutral excitons (electron-hole pairs) and charged excitons (trions) that are stable even at room temperature. While trions directly influence …
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Band‐Edge Exciton Fine Structure and Exciton Recombination Dynamics in Single Crystals of Layered Hybrid Perovskites Open
2D perovskite materials have recently reattracted intense research interest for applications in photovoltaics and optoelectronics. As a consequence of the dielectric and quantum confinement effect, they show strongly bound and stable excit…
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Exciton–exciton annihilation and biexciton stimulated emission in graphene nanoribbons Open
Graphene nanoribbons display extraordinary optical properties due to one-dimensional quantum-confinement, such as width-dependent bandgap and strong electron–hole interactions, responsible for the formation of excitons with extremely high …
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Chemical Structure, Ensemble and Single-Particle Spectroscopy of Thick-Shell InP–ZnSe Quantum Dots Open
Thick-shell (>5 nm) InP-ZnSe colloidal quantum dots (QDs) grown by a continuous-injection shell growth process are reported. The growth of a thick crystalline shell is attributed to the high temperature of the growth process and the relati…
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Binding energies of trions and biexcitons in two-dimensional semiconductors from diffusion quantum Monte Carlo calculations Open
Excitonic effects play a particularly important role in the optoelectronic behavior of two-dimensional (2D) semiconductors. To facilitate the interpretation of experimental photoabsorption and photoluminescence spectra we provide statistic…