Publications de Nicolas Grandjean

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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 ...

High quality GaN/AlGaN multiquantum well (QW) structures were grown by ammonia molecular beam epitaxy along the (0001) polar and (11 (2) over bar0) nonpolar directions. Each sample contains three QWs with thicknesses of 2, 3, and 4 nm as well as 10 nm Al0. ...

The role of deep defects and their physical origin in InGaN/GaN LED are still widely investigated and debated, in particular their impact on the electrical and optical characteristics and on the reliability of the device. In this paper we evaluate 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 ...

It is observed experimentally that high electron mobility transistor devices with short channel length processed from nitride AlInN/AlN/GaN heterostructures containing 2D electron gases (2DEGs) with densities beyond 2 x 10(13) cm(-2) exhibit temperatures u ...

Electrochemistry and biochemistry have always been ideal applications for diamond due to its chemical inertness and stability, sensitivity and biocompatibility. Several diamond ChemFET concepts have been proposed to date, however further improvements are s ...

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 ...

III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, ...

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 ...

We present a combined low-temperature time-resolved cathodoluminescence and photoluminescence study of exciton recombination mechanisms in a 3.8 nm thick a-plane (Al,Ga)N/GaN quantum well (QW). We observe the luminescence from QW excitons and from excitons ...

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 reduction of the tensile stress contained in GaN layers grown oil sapphire by metalorganic vapor phase epitaxy (MOVPE) is achieved using a low density of initial GaN crystallites. The template layers exhibit a significant reduction in dislocation densi ...

Grown on a (111) high-resistivity silicon substrate, 0.1-mu m gate AlInN/GaN high-electron mobility transistors (HEMTs) achieve a maximum current density of 1.3 A/mm, an extrinsic transconductance of 330 mS/mm, and a peak current gain cutoff frequency as h ...

Nicolas Grandjean

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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

Different pressure behavior of GaN/AlGaN quantum structures grown along polar and nonpolar crystallographic directions

Modeling the electrical characteristic of InGaN/GaN blue-violet LED structure under electrical stress

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

Self heating in AlInN/AlN/GaN high power devices: Origin and impact on contact breakdown and IV characteristics

Combining diamond electrodes with GaN heterostructures for harsh environment ISFETs

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

Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

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

Exciton recombination dynamics in a-plane (Al,Ga)N/GaN quantum wells probed by picosecond photo and cathodoluminescence

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

Stress control in GaN/sapphire templates for the fabrication of crack-free thick layers

102-GHz AlInN/GaN HEMTs on Silicon With 2.5-W/mm Output Power at 10 GHz