BOUCHOULE , Sophie

The interest in flexible light-emitting diodes (LEDs) is growing, and some more specific applications can also be found inbiomedical research. Compared to organic LEDs, devices based on inorganic semiconductor LEDs (ILEDs) present theadvantage of high luminance and brightness. Additionally, these ILEDs are much more promising as far as...

The polariton emission in a microcavity is usually measured from the surface, and little is known about the actual role of guided modes below the light cone in air, that can couple to the exciton transition, collect part of the emission and contribute to polariton losses. In this work we investigate a ZnO planar microcavity with mesas. The...

The polarization discontinuity across interfaces in polar nitride-based heterostructures can lead to the formation of two-dimensional electron and hole gases. In the past, the observation of these electron and hole gases has been achieved through various experimental techniques, most often by electronic measurements but occasionally by optical...

The interest in flexible micro light-emitting diodes (μLEDs) is growing , and specific applications can be found in biomedical research. For example, in optogenetics stimulations GaN-based μLEDs are good candidates, however, LEDs with reduced dimensions, and improved flexibility (typical dimensions < 50μm and radius of curvature (ROC) down to ~...

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The coherent emission of exciton polaritons was proposed as a means of lowering the lasing threshold because it does not require the dissociation of excitons to obtain an electron-hole plasma, as in a classical semiconductor laser based on population inversion. In this work we propose a method to prove clearly the polaritonic nature of lasing...

The formation and propagation of a polariton condensate under tightly focused excitation is investigated in a ZnO microcavity both experimentally and theoretically. 2D near-field and far-field images of the condensate are measured under quasi-continuous non-resonant excitation. The corresponding spatial profiles are compared to a model based on...

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We report on the fabrication and characterization of flexible blue thin-film micro-LED grown by MOVPE.Two approaches are explored to replace laser lift-off for the micro-LED device liberation from the growth substrate:the release of the micro-LED structures assisted by quasi-van der Waals epitaxy using an interfacial h-Bn layer; andthe...

Spatial observation and optical manipulation of polariton quantum liquids are raising a large interest in the studies of polariton condensates in microcavities [1]. In this work, we report the study of polariton condensates in a semi-hybrid ZnO microcavity where the condensation of polaritons up to room temperature has been achieved. This...

The lasing operation of a ZnO planar microcavity under optical pumping is demonstrated from T=80 K to 300 K. At the laser threshold, the cavity switches from the strong coupling to the weak coupling regime. A gain-related transition, which appears while still observing polariton branches and, thus, with stable excitons, is observed below 240K....

ZnO est un matériau semiconducteur présentant des excitons forts, en terme de force d'oscillateur et d'énergie de liaison. Il est donc particulièrement intéressant pour la génération et le contrôle de condensats de polaritons, jusqu'à température ambiante.La réalisation de microcavités ZnO planaires de grand facteur de qualité a longtemps...

The spatial dynamics of the formation of a polariton condensate under a tightly focused excitation is imaged through 2D near-field and far-field 2D tomography in a ZnO microcavity, up to room temperature. The modelling exhibits the role of the outwards polariton flux caused by the reservoir repulsion, that leads to a 3 to 10 fold increase of...

We create polariton clouds and polariton condensates to characterize their propagation at different temperatures. Our experimental results show that in a thickness gradient microcavity, polariton propagation is mainly ballistic and does not depend on the microcavity gradient. Above threshold, we compare the experimental results to a theoretical...

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The slab waveguide geometry is attracting more and more interest in the field of polaritonics. Waveguide polaritons are obtained when an excitonic transition and a slab guided mode are brought in the strong coupling regime, in strong analogy with cavity polaritons in Fabry-Perot resonators. Waveguide polaritons have been first demonstrated in...

Exciton-photon coupling in a waveguide geometry is attracting more and more interest in the field of polaritonics. Waveguide polaritons are obtained when the exciton and the guided mode of a photonic waveguide are brought in the strong coupling regime, in strong analogy with cavity polaritons in Fabry-Perot resonators. One of the first...

Semiconductor-based microcavities appear as a prolific system for studying light-matter interaction between a spatially-confined photonic mode and an excitonic resonance. The quasiparticles arising from this coupling (microcavity-polaritons) have enabled in the last years the observation of new lasing regimes as well as polariton Bose-Einstein...

In order to achieve polariton lasing at room temperature, a new fabrication methodology for planar microcavities is proposed: a ZnO-based microcavity in which the active region is epitaxially grown on an AlGaN/AlN/Si substrate and in which two dielectric mirrors are used. This approach allows us to simultaneously obtain a high-quality active...

Semiconductor-based microcavities appear as a prolific system for studying light-matter interaction between a spatially-confined photonic mode and an excitonic resonance. The quasiparticles arising from this coupling (microcavity-polaritons) have enabled in the last years the observation of new lasing regimes as well as polariton Bose-Einstein...

The strong coupling regime in a ZnO microcavity is investigated through room temperature photoluminescence and reflectivity experiments. The simultaneous strong coupling of excitons to the cavity mode and the first Bragg mode is demonstrated at room temperature. The polariton relaxation is followed as a function of the excitation density. A...

The polariton emission in a microcavity is usually measured from the surface, and little is known about the actual role of guided modes below the light cone in air; these can couple to the exciton transition and give rise to additional polaritons branches, creating thereby a polaritons leak channel, and can further collect part of the...