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Last name: ALLOING
First name: Blandine
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The development of flexible optoelectronic devices has led to the appearance of new applications, ranging from wearable displays to medical implants. Hence, strategies have been developed to make flexible every component of the devices, including the light-emitting part. One such approach relies on the use of micro-or nano-light emitting diodes...
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 research on GaN lasers aims for a continuous reduction of the lasing threshold. An approach to achieve it consists in exploiting stimulated polariton scattering. This mechanism, and the associated polariton lasers, requires an in-depth knowledge of the GaN excitonic properties, as polaritons result from the coupling of excitons with...
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...
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Optically pumped whispering-gallery mode (WGM) lasing is observed from a thin-film GaN microdisk processed from GaN-on-Si InGaN/GaN multi-quantum well wafers by selective wet-etch removal of the substrate. Compared with thin-film microdisks processed from GaN-on-sapphire wafers through laser lift-off of the sapphire substrate, the exposed...
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Optically-pumped whispering-gallery mode (WGM) lasing is observed from thin-film GaN microdisk processed from GaN-on-Si InGaN/GaN multi-quantum well wafers by selective wet etch removal of the substrate. Compared to thinfilm microdisks processed from GaN-onsapphire wafers through laser lift-off of the sapphire substrate, the exposed surface is...
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This work illustrates the potential of dark-field X-ray microscopy (DFXM), a 3D imaging technique of nanostructures, in characterizing novel epitaxial structures of gallium nitride (GaN) on top of GaN/AlN/Si/SiO 2 nano-pillars for optoelectronic applications. The nano-pillars are intended to allow independent GaN nanostructures to coalesce into...
The advance in designing arrays of ultrathin two-dimensional optical nanoresonators, known as metasurfaces, is currently enabling a large variety of novel flat optical components. The remarkable control over the electromagnetic fields offered by this technology can be further extended to the active regime in order to manipulate the light...
In this paper, we report the use of three pendeo-epitaxy growth approaches as a way of reducing the threading dislocation density (TDD) of 20 × 20 μm$^2$ GaN platelets to be used for the development of micro light-emitting diodes (μLEDs). The method relies on the coalescence of GaN crystallites grown on top of a network of deformable pillars...
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Nanopatterning of GaN/AlN layers on Silicon-On-Insulator (SOI) substrates is discussed with the aim of fabricating nanopillar arrays that can be used for subsequent GaN pendeo-epitaxy. The principle of the developed epitaxy process is that GaN crystallites are grown on deformable nano-pedestals able to rotate at GaN growth temperature. The...
Nanopatterning of GaN/AlN layers on Silicon-On-Insulator (SOI) substrates is discussed with the aim of fabricating nanopillar arrays that can be used for subsequent GaN pendeo-epitaxy. The principle of the developed epitaxy process is that GaN crystallites are grown on deformable nano-pedestals able to rotate at GaN growth temperature. The...
Nanopendeo-epitaxy of gallium nitride (GaN) is considered in this study as a way of producing freestanding GaN with reduced strain and threading dislocation density (TDD) for optoelectronic applications. The novelty of this work lies in the use of silicon on insulator (SOI) substrates patterned into nano-pillars down to the buried oxide (BOX)....
Low-threshold lasing under pulsed optical pumping is demonstrated at room temperature for III-nitride microdisks with InGaN/GaN quantum wells on Si in the blue spectral range. Thresholds in the range of 18 kW/cm 2 have been achieved along with narrow linewidths of 0.07 nm and a large peak to background dynamic of 300. We compare this threshold...
Nano-engineering III-Nitride semiconductors offers a route to further control the material and optoelectronic properties, enabling novel functionalities and applications. Although various lithography techniques are employed to nano-engineer these materials, the scalability and cost of the fabrication process can be an obstacle for...
Ultraviolet microdisk lasers are integrated monolithi-cally into photonic circuits using a III-nitride on silicon platform with gallium nitride (GaN) as the main waveguiding layer. The photonic circuits consist of a microdisk and a pulley waveguide terminated by out-coupling gratings. We measure quality factors up to 3500 under continuous-wave...
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A broadband ultraviolet light source using GaN quantum dots formed on hexagonal truncated pyramid structures Broadband ultraviolet (UV) emission has been achieved from the GaN quantum dots grown on diff erent facets of hexagonal truncated pyramidal structures. The GaN-based structures include both semipolar and polar facets, on which the...