DAMILANO , Benjamin

(Ga,In)N-based light emitting devices are very efficient in producing blue light and to a lesser extent green. Extending their spectral range to longer wavelengths while maintaining high efficiency is a challenge due to material and physical issues related to high-In content (Ga,In) N alloys. We review the current status of yellow and red...

International audience

Les propriétés germicides des rayonnements ultraviolets (UV) suscitent un intérêt de plus en plus important dans les domaines d'applications stratégiques que sont l'environnement et la santé. Les diodes électroluminescentes (LEDs) semi-conductrices à base de nitrure d'aluminium et de gallium représentent les nouvelles sources d'émission UV qui...

Here we use off-axis electron holography combined with advanced transmission electron microscopy techniques to understand the opto-electronic properties of AlGaN tunnel junction (TJ)-light-emitting diode (LED) devices for ultraviolet emission. Four identical AlGaN LED devices emitting at 290 nm have been grown by metal–organic chemical vapour...

In this work, strain relaxation in green-red emitting InGaN/GaN quantum well (QW) structures are investigated by transmission electron microscopy. In these structures, high indium content QW strain relaxation takes place through hexagonal domains formation inside GaN barrier just on QW top. With In increases, domains become limited by I1...

The polarization of the light emitted by an ultraviolet light-emitting diode (LED) has a direct impact on the device performance: a transverse electric polarization of the emission is preferred for extraction from the surface of the diode grown along the c axis. While this is the case for most UV LEDs grown on AlN, this state of events could be...

Selective area thermal etching (SATE) of gallium nitride is a simple subtractive process for creating novel device architectures and improving the structural and optical quality of III-nitridebased devices. In contrast to plasma etching, it allows, for example, the creation of enclosed features with extremely high aspect ratios without...

The variation of the internal quantum efficiency (IQE) of single InGaN quantum well structures emitting from blue to red is studied as a function of the excitation power density and the temperature. By changing the well width, the indium content, and adding a strain compensation AlGaN layer, we could tune the intrinsic radiative recombination...

III-Nitride semiconductors offer a versatile platform for integrated photonic circuits operating from the ultraviolet to the near-infrared spectral range. Either pure AlN or pure GaN waveguiding layers have usually been investigated so far. In this work, we report on the study of GaN/AlN bilayers epitaxially-grown on a sapphire substrate for...

The Auger effect and its impact on the internal quantum efficiency (IQE) of yellow light emitters based on silicon-doped InGaN–AlGaN–GaN quantum wells are investigated by power dependence measurement and using an ABC model. Photoluminescence intensity recorded as a function of excitation power density follows a linear dependence up to a...

Recombination dynamics in InGaN/GaN quantum wells has been studied by time resolved photoluminescence (PL). The radiative recombination processes in these systems can be qualitatively explained on a nanometer-scale by a model based on the recombination dynamics of two dimensional "pseudo-donor–acceptor pairs".

We present an experimental and theoretical study of the size dependence of the coupling between electron–hole pairs and longitudinal-optical phonons in Ga1−xInxN/GaN-based quantum wells and quantum boxes. We found that the Huang–Rhys factor S, which determines the distribution of luminescence intensities between the phonon replicas and the...

International audience

No description

International audience

International audience

National audience

In this work, InGaN/GaN Multi-Quantum Wells (MQWs) with strain compensating AlGaN interlayers grown by metalorganic vapour phase epitaxy have been investigated by high resolution X-ray diffraction, transmission electron microscopy and photoluminescence (PL). For different AlGaN strain compensating layer thicknesses varying from 0 to 10.6 nm, a...

International audience

Abstract It is shown that substrate pixelisation before epitaxial growth can significantly impact the emission color of semiconductor heterostructures. The wavelength emission from In x Ga 1−x N/GaN quantum wells can be shifted from blue to yellow simply by reducing the mesa size from 90 × 90 µm 2 to 10 × 10 µm 2 of the patterned silicon used...

We analyze the room temperature photoluminescence properties of several multilayer stackings of GaN/AlN quantum dots. We report drastic differences of emission energies and linewidths between continuous wave and time-resolvedphotoluminescence experiments. In continuous wave experiments, the screening of internal electric fields by accumulation...

Dipolar, or indirect excitons (IXs) offer a rich playground for both design of novel optoelectronic devices and fundamental many-body physics. Wide GaN/(AlGa)N quantum wells host a new and promising realization of such excitons. Indeed, compared to their counterparts in GaAs-based heterostructures, IXs in nitrides possess two key advantages....

Relying on the local orientation of nanostructures, Pancharatnam-Berry metasurfaces are currently enabling a new generation of polarization-sensitive optical devices. A systematical mesoscopic description of topological metasurfaces is developed, providing a deeper understanding of the physical mechanisms leading to the polarization-dependent...