Publications associées à Engineering the spatial confinement of exciton polaritons in semiconductors

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté

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 ...

AIP Publishing2023

Ultrafast carrier and quasiparticle dynamics in strongly confined perovskite nanoplatelets

Etienne Christophe Socie

Over the past decade, lead halide perovskites (LHPs) have received considerable attention thanks to their impressive optoelectronic properties. Today, LHP-based devices are one of the most efficient single-junction solar cells, with power-conversion effici ...

EPFL2022

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Single molecule fluorescence and phosphorescence studies using a scanning tunneling microscope

Abhishek Grewal

This thesis investigates novel single-molecule luminescence phenomena at their inherent, sub-molecular length scale. The microscopic understanding of luminescence processes will be crucial for the continued improvement of organic optoelectronic and semicon ...

EPFL2022

Interaction of Confined Polaritons in Microcavity Structures

Morteza Navadeh Toupchi

A polariton is a quasiparticle formed from the coupling of a confined photon in a cavity to electronic excitation, like exciton in a semiconductor. This dissertation reports on series of experiments in confined polariton interaction by design, fabrication, ...

EPFL2021

Strong plasmon-exciton coupling in transition metal dichalcogenides and plasmonic nanostructures

Yang Li, Wen Chen

Achieving strong coupling between emitters and cavity photons holds an important position in the light-matter interaction due to its applications such as polariton lasing, all-optical switches, and quantum information processing. However, room-temperature ...

ROYAL SOC CHEMISTRY2021

Direct measurement of key exciton properties: Energy, dynamics, and spatial distribution of the wave function

Martin Wolf, Michele Puppin

Excitons, Coulomb-bound electron-hole pairs, are the fundamental excitations governing the optoelectronic properties of semiconductors. Although optical signatures of excitons have been studied extensively, experimental access to the excitonic wave functio ...

Wiley2021

Toward Bright and Pure Single Photon Emitters at 300 K Based on GaN Quantum Dots on Silicon

Nicolas Grandjean, Raphaël Butté, Sebastian Pascal Tamariz Kaufmann, Johann Nicolaï Stachurski, Kanako Shojiki, Gordon Jens Callsen

Quantum dots (QDs) based on III-nitride semi-conductors are promising for single photon emission at noncryogenic temperatures due to their large exciton binding energies. Here, we demonstrate GaN QD single photon emitters operating at 300 K with g((2)) (0) ...

AMER CHEMICAL SOC2020

Exciton and Carrier Dynamics in Two-Dimensional Perovskites

Jacques-Edouard Moser, Marine Eva Fedora Bouduban, Etienne Christophe Socie, Andrés Burgos Caminal

Two-dimensional Ruddlesden−Popper hybrid lead halide perovskites have become a major topic in perovskite optoelectronics. Here, we aim to unravel the ultrafast dynamics governing the evolution of charge carriers and excitons in these materials. Using a com ...

2020

Probing Alloy Formation Using Different Excitonic Species: The Particular Case of InGaN

Nicolas Grandjean, Raphaël Butté, Gordon Jens Callsen

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 ...

American Physical Society2019

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

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

Electron Dynamics in Anatase TiO2 Nanoparticles by Ultrafast Broadband Deep-Ultraviolet Spectroscopy

Majed Chergui, Gerald Auböck, Tania Palmieri, Edoardo Baldini, Enrico Pomarico

The optical bandgap of anatase TiO2 nanoparticles is dominated by bulk absorption bands in the deep-ultraviolet due to strongly bound excitons. These spectral features can be utilized as a sensitive probe of carrier and lattice dynamics inside the TiO2 nan ...

E D P SCIENCES2019

Light-Matter Interaction in III-Nitride Waveguides: Propagating Polaritons and Optical Gain

Joachim Armand Simonne Ciers

III-nitride waveguides featuring AlInN claddings and GaN/AlGaN quantum wells (QWs) offer promising perspectives for applications in many fields of short-wavelength photonics. Thanks to their nearly lattice-matched nature, these structures exhibit an excell ...

EPFL2018

Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2Nanoparticles

Majed Chergui, Gerald Auböck, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Enrico Pomarico, Malte Oppermann

The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as se ...

American Chemical Society (ACS)2018

On the physics of multimode polaritons

Claudéric Ouellet-Plamondon

This thesis is devoted to the study of microcavity polariton systems, in which the strong coupling occurs between more than one exciton or photon modes i.e. multimode polaritons. The first part of this work states the theoretical background of light-matter ...

EPFL2017

Propagating Polaritons in III-Nitride Slab Waveguides

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Gwénolé Jean Jacopin, Joachim Armand Simonne Ciers

We report on III-nitride waveguides with c-plane GaN/(Al,Ga)N quantum wells in the strong light-matter coupling regime supporting propagating polaritons. They feature a normal-mode splitting as large as 60 meV at low temperatures thanks to the large overla ...

American Physical Society (APS)2017

Strongly bound excitons in anatase TiO2 single crystals and nanoparticles

Helmuth Berger, Marco Grioni, Majed Chergui, Arnaud Magrez, Gerald Auböck, Simon Karl Moser, Edoardo Baldini

Anatase TiO2 is among the most studied materials for light-energy conversion applications, but the nature of its fundamental charge excitations is still unknown. Yet it is crucial to establish whether light absorption creates uncorrelated electron-hole pai ...

Nature Publishing Group2017

Bosonic lasing and trapping of a dressed photon fluid in InGaN at room temperature

Munise Nevin Cobet

The generation of a quantum fluid of dressed photons at room temperature is experimentally demonstrated in an InGaN microcavity which is divided into two-and one-dimensional sections, resulting in single- and switchable multilevel coherent light emission. ...

Amer Physical Soc2016

Hybridization and electron-phonon coupling in ferroelectric BaTiO3 probed by resonant inelastic x-ray scattering

Marco Grioni, Simon Karl Moser, Sara Fatale

We investigated the ferroelectric perovskite material BaTiO3 by resonant inelastic x-ray scattering (RIXS) at the Ti L-3 edge. We observe with decreasing temperature a transfer of spectral weight from the elastic to the charge-transfer spectral features, i ...

Amer Physical Soc2016