Jean-François Carlin

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

We report a thorough study of the growth of self-assembled GaN/AlN quantum dots (QDs). These QDs were grown on sapphire substrates using the Stranski-Krastanov (SK) growth mode by means of low-pressure metal organic vapor phase epitaxy. The influence of th ...

Laser action with low threshold average pump power density (similar to 50 W. cm(-2)) at room temperature is reported for a crack-free planar vertical cavity surface emitting laser (VCSEL) structure based on a bottom lattice-matched AllnN/GaN distributed Br ...

Blue light-emitting diodes based on III-nitride semiconductors are nowadays widely used for solid-state lighting. They exhibit impressive figures of merit like an internal quantum efficiency close to 100%. This value is intriguing when considering the high ...

We present a study on the dependence of the external Quantum Efficiency (QE) of Light Emitting Diodes (LEDs) on the device properties and p-contact metallisation. The external QE could be doubled by changing the p-type contact from oxidised Ni/Au to non-annealed Ag. The best value for the external QE of an unpackaged device is 13.5% and is obtained when the reflection from the Ag mirror contact is in phase with the QW emission.

We measure the charge carrier recombination coefficients of InGaN quantum wells by analyzing the dynamical properties of (Al,In)GaN laser diodes emitting in the violet spectral range. Relaxation oscillations and turn-on delays are fitted to a rate equation ...

The electron optical phase contrast probed by electron holography at n-n+ GaN doping steps is found to exhibit a giant enhancement, in sharp contrast to the always smaller than expected phase contrast reported for p-n junctions. We unravel the physical ori ...

We optimized the far-field emission pattern of one-dimensional photonic crystal nanobeams by modulating the nanobeam width, forming a sidewall Bragg cross-grating far-field coupler. By setting the period of the cross-grating to twice the photonic crystal p ...

We report on the growth by metalorganic vapor phase epitaxy of a InGaN/GaN resonant-cavity light emitting diode (RCLED) emitting at 454 nm and incorporating a 12-pair Al0.82In0.18N/GaN distributed Bragg reflector as bottom mirror. A(1-x)In(x)N layers with an Al content around x similar to 0.17 are lattice matched to GaN, thus avoiding strain-related issues in the subsequent active layers while keeping a high refractive index contrast of 7%, comparable to that achievable in the Al0.5Ga0.5N/GaN system. Device

Room temperature electron mobility of 1170 cm(2)/V s is obtained in an undoped, lattice-matched, Al0.82In0.18N/GaN field-effect transistor heterostructure, while keeping a high (2.6 +/- 0.3)x10(13) cm(-2) electron gas density intrinsic to the Al0.82In0.18N ...

Forward and reverse leakage currents in GaN/InGaN multi-quantum well light-emitting diodes (LEDs) are caused by reactive-ion etching (RIE) damages during device patterning. A method to recover the damaged surfaces, based on a chemical etch in KOH: ethylene ...

The authors have studied InxGa1-xN/GaN (x approximate to 15%) quantum wells (QWs) using atomic force microscopy (AFM) and picosecond time resolved cathodoluminescence (pTRCL) measurements. They observed a contrast inversion between monochromatic CL maps co ...

We report an efficient extension of supercontinuum generation through dispersion engineering of crystalline aluminum nitride (AlN)-on-sapphire waveguides. Using a tailored epitaxial regrowth of AlN epilayers and an optimized fabrication protocol, the dispersion sensitivity to the waveguide cross-section was enhanced allowing for a significant reach extension of both short and long dispersive wave with optimized pumping conditions, reaching down to 550 nm in the visible and up to 4.5 mu m in the mid-infrared

Recent studies demonstrated that the performance of InGaN/GaN quantum well (QW) light emitting diodes (LEDs) can be significantly improved through the insertion of an InGaN underlayer (UL). The current working hypothesis is that the presence of the UL redu ...

It has been widely observed that an increasing carrier density in a strongly coupled semiconductor microcavity (MC) alters the dispersion of cavity polaritons, below and above the condensation threshold. The interacting nature of cavity polaritons stems fr ...

We report on the demonstration of low-loss, single-mode GaN-InAlN ridge waveguides (WGs) at fiber-optics telecommunication wavelengths. The structure grown by metal-organic vapor phase epitaxy contains AlInN cladding layers lattice-matched to GaN. For slab ...

Gate and drain-lag effects are studied in (GaN)/InAlN/GaN and InAlN/AlN/GaN HEMTs grown on sapphire. Electron trapping on the surface states between the gate and the drain forming the net negative charge up-to similar to 2 x 10(13) cm(-2) is found to be re ...

AllnN/GaN high electron mobility transistors (HEMTs) on sapphire substrate have yielded a maximum drain current density of 1.26 A/mm with a current gain cutoff and maximum oscillation frequencies about 26 and 40 GHz, respectively, for a 0.25 mu m gate leng ...

In this work, we report on the efficiency of single InGaN/GaN quantum wells (QWs) grown on thin (

The high temperature stability of AlGaN/GaN and lattice-matched InAlN/GaN heterostructure FETs has been evaluated by a stepped temperature test routine under large-signal operation. While AlGaN/GaN high-electron mobility transistors (HEMTs) have failed in ...

A room temperature polariton condensate realized in a microcavity with embedded GaN quantum wells emits linearly polarized light at threshold with the plane of polarization pinned to one of the crystallographic axes. With increasing pumping power, a depinn ...

Jean-François Carlin

Chat with Graph Search

Stranski-Krastanov GaN/AlN quantum dots grown by metal organic vapor phase epitaxy

Blue lasing at room temperature in an optically pumped lattice-matched AlInN/GaN VCSEL structure

GaN surface as the source of non-radiative defects in InGaN/GaN quantum wells

GaN-based single mirror light emitting diodes

Recombination coefficients of GaN-based laser diodes

Origin of giant enhancement of phase contrast in electron holography of modulation-doped n-type GaN

Far-field coupling in nanobeam photonic crystal cavities

InGaN/GaN resonant-cavity LED including an AlInN/GaN bragg mirror

High electron mobility lattice-matched AlInN/GaN field-effect transistor heterostructures

Suppression of leakage currents in GaN-based LEDs induced by reactive-ion etching damages

High spatial resolution picosecond cathodoluminescence of InGaN quantum wells

Three-octave Supercontinuum Generation in Thick Crystalline Aluminum Nitride Waveguides

Defect incorporation in In-containing layers and quantum wells: experimental analysis via deep level profiling and optical spectroscopy

Impact of saturation on the polariton renormalization in III-nitride based planar microcavities

Lattice-matched GaN-InAlN waveguides at lambda=1.55 mu m grown by metal-organic vapor phase epitaxy

Gate-lag and drain-lag effects in (GaN)/InAlN/GaN and InAlN/AlN/GaN HEMTs

Evaluation of AllnN/GaN HEMTs on sapphire substrate in microwave, time and temperature domains

Investigation of the Impact of Point Defects in InGaN/GaN Quantum Wells with High Dislocation Densities

Testing the Temperature Limits of GaN-Based HEMT Devices

Pinning and Depinning of the Polarization of Exciton-Polariton Condensates at Room Temperature