Publications de Raphaël Butté

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Since the early 1960s, alloys are commonly grouped into two classes that feature either bound states in the band gap (I) or additional, nondiscrete band states (II). Consequently, one can observe either excitons bound to isoelectronic impurities or the typ ...

We present the simultaneous optical and thermal analysis of a freestanding photonic semiconductor membrane made from wurtzite III-nitride material. By linking microphotoluminescence spectroscopy with Raman thermometry and other spectroscopic techniques, we ...

The main emission characteristics of electrically driven polariton lasers based on planar GaN microcavities with embedded InGaN quantum wells are studied theoretically. The polariton emission dependence on pump current density is first modeled using a set ...

We present a methodology to quantify polarization and electron affinity changes at interfaces by combining scanning tunneling spectroscopy, off-axis electron holography in transmission electron microscopy (TEM), and self-consistent calculations of the elec ...

We report the observation of well-resolved A and B excitonic resonances in the reflectivity spectra of a wedged GaN/AlGaN quantum well (QW) with 5% Al content in the barriers for different well thicknesses. For the thicker well cases, the energy splitting ...

We report on the epitaxial growth of high-quality core-shell nonpolar m-plane GaN/InAlN multiple quantum wells (MQWs) on the sidewall facets of c-oriented hexagonal GaN wires. Pseudomorphic growth without generation of threading dislocations has been estab ...

Microcavity polaritons are strongly interacting hybrid light-matter quasiparticles, which are promising for the development of novel light sources and active photonic devices. Here, we report polariton lasing in the UV spectral range in microring resonator ...

We report broad bandwidth blue superluminescent light-emitting diodes (SLEDs) based on a short-cavity active region. The dependencies of amplified spontaneous emission (ASE) output power and gain bandwidth on cavity length were investigated in devices whos ...

Since the 1960s, alloys are grouped into two classes, featuring bound states in the bandgap (I - GaP:N, ZnTe:O, etc.) or additional, non-discrete, band states (II - SiGe, GaAsP, InGaAs, etc.). Therefore, one can observe either a rich and informative zoo of ...

The electrical properties, electroluminescence (EL) power output and deep trap spectra were studied before and after 5 MeV electron irradiation of near-UV single-quantum-well (SQW) light-emitting diodes (LED) structures differing by the presence or absence ...

Two types of near-UV light-emitting diodes (LEDs) with an InGaN/GaN single quantum well (QW) differing only in the presence or absence of an underlayer (UL) consisting of an InAlN/GaN superlattice (SL) were examined. The InAlN-based ULs were previously sho ...

The growth of highly-reflective nitride-based distributed Bragg reflectors (DBRs) and their use in vertical cavity structures is reviewed. We discuss the various nitride material systems employed to design Bragg mirrors and microcavities, namely the Al-x(G ...

The growth of InGaN quantum wells ( QWs) by metal-organic vapour phase epitaxy is investigated by atomic force microscopy ( AFM). It is shown that for low growth temperatures the surface morphology of the thin InGaN well layer ( 1.5 nm) exhibits a meanderi ...

By performing pump-probe experiments, we study the relaxation dynamics of spin-polarized excitons in a wurtzite GaN/AlGaN quantum well (QW)grown by metal organic vapor phase epitaxy. The circular degree of polarization of the differential reflectivity sign ...

We report on the properties of III-nitride based microcavities (MCs) operating in the strong coupling regime (SCR) up to room temperature. We first discuss why this class of materials is well suited to investigate the physics of cavity polaritons, which ar ...

A detailed experimental investigation of the phonon-assisted emission in a high-quality c-plane GaN epilayer is presented up to 200 K. By performing photoluminescence and reflectivity measurements, we find important etaloning effects in the phonon-replica ...

Applications such as optical clocks, gas spectroscopy, and optical coherent tomography stand to benefit significantly from the integration of on-chip supercontinuum sources. Materials exhibiting both second- and third-order nonlinearities are particularly ...

The electrical properties and deep trap spectra were compared for near-UV GaN/InGaN quantum well (QW) structures grown on free-standing GaN substrates. The structures differed by the presence or absence of a thin (110 nm) InGaN layer inserted between the h ...

We report a numerical and experimental investigation of fabrication tolerances and outcoupling in optically pumped III-nitride nanolasers operating near lambda = 460 nm, in which feedback is provided by a one-dimensional photonic crystal nanobeam cavity an ...

IIIV photonics on silicon is an active and promising research area. Here, we demonstrate room-temperature (RT) lasing in short-wavelength III-nitride photonic crystal nanobeam cavities grown on silicon featuring a single InGaN quantum well (QW). In the low ...

Raphaël Butté

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Probing Alloy Formation Using Different Excitonic Species: The Particular Case of InGaN

Optical and thermal characterization of a group-III nitride semiconductor membrane by microphotoluminescence spectroscopy and Raman thermometry

Generic picture of the emission properties of III-nitride polariton laser diodes: Steady state and current modulation response

Interplay of anomalous strain relaxation and minimization of polarization changes at nitride semiconductor heterointerfaces

Quantum confinement dependence of the energy splitting and recombination dynamics of A and B excitons in a GaN/AlGaN quantum well

M-Plane GaN/InAlN Multiple Quantum Wells in Core-Shell Wire Structure for UV Emission

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Broadened Bandwidth Amplified Spontaneous Emission from Blue GaN-Based Short-Cavity Superluminescent Light-Emitting Diodes

Probing alloy formation using different excitonic species: The particular case of InGaN

Effects of 5 MeV electron irradiation on deep traps and electroluminescence from near-UV InGaN/GaN single quantum well light-emitting diodes with and without InAlN superlattice underlayer

Effects of InAlN underlayer on deep traps detected in near-UV InGaN/GaN single quantum well light-emitting diodes

Recent progress in the growth of highly reflective nitride-based distributed Bragg reflectors and their use in microcavities

Growth mode induced carrier localization in InGaN/GaN quantum wells

Spin relaxation of free excitons in narrow GaN/AlxGa1-xN quantum wells

Tailoring the strong coupling regime in III-nitride based microcavities for room temperature polariton laser applications

Probing exciton density of states through phonon-assisted emission in GaN epilayers: A and B exciton contributions

Multi-octave bandwidth supercontinuum generation in crystalline Aluminum Nitride-on-sapphire waveguides

Deep traps in InGaN/GaN single quantum well structures grown with and without InGaN underlayers

Fabrication defects and grating couplers in III-nitride photonic crystal nanobeam lasers (Conference Presentation)

Continuous Wave Blue Lasing in III-Nitride Nanobeam Cavity on Silicon