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.

Fluoride plasma treatment similar to that used in AlGaN/GaN HEMTs has been applied to InAlN/GaN HEMTs. Enhancement mode of operation is obtained with a pinch-off voltage shifted by 3 V. Owing to the fluoride treatment an increase of the forward gate thresh ...

The capacitance-voltage-temperature characteristics of nonintentionally doped In0.16Al0.84 N/n+- GaN Schottky diodes were measured at 1 MHz and in the 90–400 K range. They are discussed in the framework of existing theories, which properly treat the Poiss ...

Our interest is centred on the very thin layers consisting of only one or a few monolayers of InAs. The optical transition energies, measured by photoluminescence spectroscopy, are compared with theoretical calculations obtained in envelope function approximation and through an empirical tight-binding method. This comparison yields values for the not well-known valence band offset at the InAs/InP interface, and the luminescence lines observed at different energies could be assigned to layers between one and

We report on the current properties of Al1-x InxN (x approximate to 0.18) layers lattice- matched ( LM) to GaN and their specific use to realize nearly strain- free structures for photonic and electronic applications. Following a literature survey of the g ...

The concept of field-effect transistor with ferroelectric gate in combination with the advanced technique of direct domain writing is applied for modulation of transport properties of 2D electron gas located close to the interface in a GaN/AlGaN heterostru ...

We observe a room-temperature low-threshold transition to a coherent polariton state in bulk GaN microcavities in the strong-coupling regime. Nonresonant pulsed optical pumping produces rapid thermalization and yields a clear emission threshold of 1 mW, co ...

We investigate the dynamics of donor bound excitons (D degrees X-A) at T = 10K around an isolated single edge dislocation in homoepitaxial GaN, using a picosecond time-resolved cathodoluminescence (TR-CL) setup with high temporal and spatial resolutions. A ...

We study the deep levels in InAlN nearly lattice-matched to GaN by photocapacitance spectroscopy. This technique allows the study of very deep levels having too slow thermal emission rates to be detected by other deep level spectroscopy techniques. We will ...

We report on the growth by metalorganic vapor phase epitaxy of high-quality Al1-xInxN layers and AlInN/GaN Bragg mirrors near lattice matched to GaN. Layers are grown on a GaN buffer layer with no cracks over full 2 in. sapphire wafers. The index contrast relative to GaN is around 7% for wavelengths ranging from 950 to 450 nm. We demonstrate the growth of a crack-free, 20 pairs Al0.84In0.16N/GaN distributed Bragg reflector centered at 515 nm with an over 90% reflectivity and a 35 nm stop band. The growth of

We discuss the growth of lattice matched GaInAs, GaInAsP and GaInAsP/GaInAs multiple quantum well structures for high speed laser applications. Optical cavities, including five 90 angstrom GaInAs quantum wells with GaInAsP barriers and waveguides showed a 4 K photoluminescence line width of 8.7 meV. Transmission electron microscopy and X-ray diffraction confirm the good control over the growth of these structures.

Off-axis electron holography is utilized to identify point defect reactions and quantify their dynamics by probing the time and temperature dependence of the Fermi level upon annealing. The methodology is illustrated using implanted carbon (C) in GaN, wher ...

The signature of the strong-coupling regime is unambiguously evidenced in a GaN-based microcavity (MC) above the polariton lasing threshold P-thr at room temperature through the observation of the upper polariton branch. The MC system exhibits a renormaliz ...

We report the growth behaviour of InP, InGaAs and InGaAsP on non-planar InP substrates where ridges were formed with (111)A, (211)A, (111)B and (551BAR) sidewall planes. All three materials grow uniformly on the whole patterned surface with (111)A and (211)A sidewall planes. They grow separately on the plateau and in the valley for the other two structures. The growth front of the InGaAs films is always rippled near the sidewalls, indicating large deviations from lattice-matched composition in these areas,

We propose a model for leakage currents in Schottky contacts on InAlN/GaN heterostructures based on two distinct tunneling mechanisms. Our modeling relies on structural parameters, in particular, InAlN dielectric constant, interface polarization charges an ...

The mechanisms contributing to experimental quality factors of shortwavelength (lambda = 440-480 nm) III-nitride on silicon one-dimensional photonic crystal cavities were quantified. Fluctuations in fundamental and first-order cavity mode wavelength and qu ...

We report the design and optical characterization of fully suspended wire waveguides and photonic crystal (PhC) membranes fabricated on a gallium nitride layer grown on silicon substrate operating at 1.5 mu m. W1-type PhC waveguides are coupled with suspen ...

We report on the experimental achievement of narrow ultraviolet excitonic and biexcitonic emission from GaN/AlGaN quantum wells. The very large biexciton binding energy (up to 12 meV) inhibits thermalization between the two species allowing to study the re ...

We present a detailed theoretical study of a vertical-cavity surface-emitting laser (VCSEL) with two optically coupled, active cavities. The study is based on a rate-equation model written for carriers and photons under steady-state conditions. The model allows one to determine all the relevant parameters-carrier densities, gains, and output powers-starting from two input parameters: the injection currents in each cavity. The system of equations is solved for different operating regimes of the device and th

We have evaluated the structure of high-reflectivity InP/InGaAsP distributed Bragg reflectors grown by chemical-beam epitaxy at a growth rate of 3 mu m/h. Transmission electron microscopy combined with electron energy loss spectroscopy indicate lateral fluctuations in the GaInAsP alloy composition, clearly visible in the 490-510 degrees C growth temperature range, but less perceptible between 460 and 480 degrees C. In the higher temperature range, the modulation in composition shows a higher frequency along

High quality AlInN was grown near lattice-matched to GaN. It shows about 7% index contrast with GaN. AlInN is thus a promising alternative to AlGaN, as demonstrated by a 20-pairs AlInN/GaN distributed Bragg reflector with over 90% reflectivity. Light emitting diodes with active layers grown on top of AlInN/GaN multi-layers exhibit internal quantum efficiencies comparable to those of reference diodes grown directly on GaN buffer, this further demonstrate that AlInN material quality can meet the needs of opto

Jean-François Carlin

Chat with Graph Search

Effect of fluoride plasma treatment on InAlN/GaN HEMTs

Capacitance behavior of InAlN Schottky diodes in presence of large concentrations of shallow and deep states related to oxygen

Optical study on ultrathin InAs/InP single quantum wells

Current status of AlInN layers lattice-matched to GaN for photonics and electronics

Ferroelectric gates with rewritable domain nanopatterns for modulation of transport properties in GaN/AlGaN heterostructures

Room-temperature polariton lasing in semiconductor microcavities

Exciton dynamics at a single dislocation in GaN probed by picosecond time-resolved cathodoluminescence

Photocapacitance spectroscopy of InAlN nearly lattice-matched to GaN

High-quality AlInN for high index contrast Bragg mirrors lattice matched to GaN

Growth of Gainas(P) and Gainasp/Gainas Mqw Structures by Cbe

Quantifying carbon site switching dynamics in GaN by electron holography

Phase diagram of a polariton laser from cryogenic to room temperature

Chemical beam epitaxy of InP, InGaAs and InGaAsP on non-planar InP substrates

Leakage mechanisms in InAlN based heterostructures

Quantification of scattering loss of III-nitride photonic crystal cavities in the blue spectral range

Near-infrared characterization of gallium nitride photonic-crystal waveguides and cavities

Biexciton kinetics in GaN quantum wells: Time-resolved and time-integrated photoluminescence measurements

Rate-equation model for coupled-cavity surface-emitting lasers

Evaluation of InP/InGaAsP distributed Bragg reflectors grown by chemical-beam epitaxy

AlInN as high-index-contrast material for GaN-based optoelectronics