Publications associées à Optical bistability in InGaN-based multisection laser diodes

Plasmonically enhanced molecular junctions for investigation of atomic-scale fluctuations in self-assembled monolayers

Molecular junctions represent a fascinating frontier in the realm of nanotechnology and are one of the smallest optoelectronic devices possible, consisting of individual molecules or a group of molecules that serve as the active element sandwiched between ...

EPFL2024

The nanoscale impact of individual nonradiative point defects on InGaN/GaN quantum wells

Thomas Fjord Kjaersgaard Weatherley

Today's world depends on optoelectronic devices: light-emitting diodes illuminate our houses and backlight the displays on our gadgets, while laser diodes underpin fibre-optic communication. Such optoelectronic devices rely on crystalline semiconductor het ...

EPFL2023

Sleptonic SUSY: from UV framework to IR phenomenology

Majid Ekhterachian

We study an attractive scenario, "Sleptonic SUSY", which reconciles the 125 GeV Higgs scalar and the non-observation of superpartners thus far with potentially pivotal roles for slepton phenomenology: providing viable ongoing targets for LHC discovery, inc ...

Springer Nature2022

Carrier Lifetimes and Recombination Pathways in Metal-Organic Frameworks

Olga Syzgantseva

Understanding the excited-state charge carrier relaxation in metal-organic frameworks (MOFs) and revealing ways to alternate its rate are of primary importance for the development of novel hybrid photoactive materials with sufficiently long carrier lifetim ...

AMER CHEMICAL SOC2019

Dynamics of nanoscale systems probed by time-resolved STM-induced luminescence

Anna Maria Roslawska

The efficiency and peculiarities of processes such as surface adsorption or electron-to-photon energy conversion in organic and inorganic structures are determined by the dynamics at the scale of individual molecules, atoms and charges. The timescales of s ...

EPFL2019

Nonequilibrium exciton physics in hybrid lead-halide perovskites and anatase titanium dioxide

Tania Palmieri

The strength of the electron-hole interaction in bulk semiconductors is not only determined by the dielectric environment, but also depends on the presence of other quasiparticles - free charge carriers or phonons - that populate the system. In the former ...

EPFL2019

Suppression of the quantum-confined Stark effect in polar nitride heterostructuresis

Antoine Cyril David Hoffmann, Gordon Jens Callsen

Recently, we suggested an unconventional approach (the so-called Internal-Field-Guarded-Active-Region Design "IFGARD") for the elimination of the quantum-confined Stark effect in polar semiconductor heterostructures. The IFGARD-based suppression of the Sta ...

NATURE PUBLISHING GROUP2018

Dynamics of Electronic and Ionic Charges in Cyanine Organic Semiconductor Devices

Sandra Christina Jenatsch

Organic semiconductor materials have been widely applied in optoelectronic devices to replace their inorganic counterparts and explore new fields of applications. Due to their high extinction coefficients, chemical tunability and solubility, cyanine dyes a ...

EPFL2017

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

Gwénolé Jean Jacopin

We report on a detailed study of the intensity dependent optical properties of individual GaN/AlN quantum disks (QDisks) embedded into GaN nanowires (NW). The structural and optical properties of the QDisks were probed by high spatial resolution cathodolum ...

Amer Physical Soc2016

Backward diodes using heavily Mg-doped GaN growth by ammonia molecular-beam epitaxy

Denis Martin, Nicolas Grandjean, Marco Malinverni, Hironori Okumura

We grew heavily Mg-doped GaN using ammonia molecular-beam epitaxy. The use of low growth temperature (740 degrees C) allows decreasing the incorporation of donor-like defects (

Amer Inst Physics2016

Increased Photoconductivity Lifetimes in GaAs Nanowires via n-Type and p-Type Shell Doping

Anna Fontcuberta i Morral, Federico Matteini, Francesca Amaduzzi

Reliable doping in GaAs nanowires is essential for the development of novel optoelectronic devices. Previously, GaAs nanowires have been shown to exhibit extremely short photoconductivity lifetimes of a few picoseconds due to their high surface recombinati ...

Ieee2016

Innovative photocatalyst (FeOx–TiO2): transients induced by femtosecond laser pulse leading to bacterial inactivation under visible light

Michaël Bensimon, Juan Kiwi, César Pulgarin, Rosendo Sanjines, Sami Rtimi

This study reports the photosensitizing effect/mechanism of FeOx under visible light irradiation and charge transfer to TiO2 on FeOx–TiO2 cosputtered film. The transients which were photo-induced by femtosecond laser pulses at 545 nm (25 fs) were identifie ...

RSC Publishing2015

Ultrafast spectroscopy of wide bandgap semiconductor nanostructures

Mehran Shahmohammadi

Group III-nitrides have been considered a promising choice for the realization of optoelectronic devices since 1970. Since the first demonstration of the high-brightness blue light-emitting diodes (LEDs) by Shuji Nakamura and coworkers, the fabrication of ...

EPFL2015

Scanning photocurrent microscopy reveals electron-hole asymmetry in ionic liquid-gated WS2 transistors

Helmuth Berger

We perform scanning photocurrent microscopy on WS2 ionic liquid-gated field effect transistors exhibiting high-quality ambipolar transport. By properly biasing the gate electrode, we can invert the sign of the photocurrent showing that the minority photoca ...

Amer Inst Physics2014

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

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Georg Rossbach

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 ...

Amer Chemical Soc2014

The nature of the quasiparticles in two benchmark transition metal oxides : a spectroscopic study of anatase TiO₂ and tetragonal CuO

Simon Karl Moser

Transition metal oxides (TMOs) are emerging strong players in many domains, ranging from superconductivity, to microelectronics to spintronics to light harvesting for photovoltaics. Beyond their non-toxicity, low corrosiveness and low price, they exhibit a ...

EPFL2014

Back Electron-Hole Recombination in Hematite Photoanodes for Water Splitting

Michael Graetzel, Maurin Cornuz, Florian Le Formal, Stanley David Tilley

The kinetic competition between electron-hole recombination and water oxidation is a key consideration for the development of efficient photoanodes for solar driven water splitting. In this study, we employed three complementary techniques, transient absor ...

American Chemical Society2014

Quantum Wire - Quantum Dot Systems Grown in Inverted Pyramids

Justyna Szeszko

Semiconductor quantum wires (QWRs) and quantum dots (QDs) are nanoscale heterostructures, which form fascinating low-dimensional systems for fundamental studies of quantum-mechanical effects and are attractive candidates for integration into optoelectronic ...

EPFL2013

Conductivity and Ferroelectric Hysteresis in Bi4Ti3O12 Single Crystals Around Room Temperature

Dragan Damjanovic, Nava Setter

The dielectric response in Bi4Ti3O12 single crystals was studied at subswitching conditions at relative low temperatures (20-250 degrees C) and frequencies (100 mHz to 10kHz) both in-plane and out-of-plane. Electron-holes are likely to be the major charge ...

Taylor & Francis Ltd2013

Linear and Time-Resolved THz Spectroscopy of Photonic and Charge Transporting Systems

Jan Cornelius Brauer

Photo-induced charge separation and charge transport are fundamental processes in many energy conversion techniques, where light is converted into chemical energy (PEC), into electrical energy (solar cells) or in the opposite sense if electrical energy is ...

EPFL2012