Publications associées à Non equilibrium anisotropic excitons in atomically thin ReS2

Ultrafast carrier and quasiparticle dynamics in strongly confined perovskite nanoplatelets

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

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

Yacora on the Web: Online collisional radiative models for plasmas containing H, H-2 or He

Maurizio Giacomin

Yacora on the Web (www.yacora.de ) is a web application providing access to collisional radiative models based on the flexible solver Yacora. The main application range is plasma diagnostics in low-pressure plasmas. Available online are three collisional r ...

2020

Low-dimensional perovskite nanoplatelet synthesis using in situ photophysical monitoring to establish controlled growth

Perovskite nanoparticles have attracted the attention of research groups around the world for their impressive photophysical properties, facile synthesis and versatile surface chemistry. Here, we report a synthetic route that takes advantage of a suite of ...

2019

The effects of radiation on ablative heat shields during atmospheric entry

Nikhil Banerji

Spacecraft employ composite materials as Thermal Protection Systems (TPS) to survive entering a planetary atmosphere at hypersonic speeds. Under intense convective and radiative heating from the surrounding shock layer, these composites decompose and erode ...

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

A femtosecond fluorescence study of vibrational relaxation and cooling dynamics of UV dyes

Majed Chergui, Olivier Christian Bräm, Andrea Cannizzo, Thomas James Penfold

We present a femtosecond broad-band fluorescence up-conversion study of the vibrational relaxation dynamics of two UV chromophores, 2,5-diphenyloxazole (PPO) and para-terphenyl (pTP), pumped with a large excess of vibrational energy (>2000 cm(-1)). The ban ...

2012

Scanning Tunneling Microscopy and Luminescence of Individual Nanostructures

Theresa Lutz

A detailed investigation and characterization of the local properties of individual nanoscopic structures is of great importance for the understanding of novel physical phenomena at the nanoscale as well as for the assessment of their possible use in futur ...

EPFL2011

Dual-Emitting Langmuir-Blodgett Film-Based Organic Light-Emitting Diodes

Mohammad Khaja Nazeeruddin, Diego Repetto

Langmuir-Blodgett (LB) films containing alternating layers of the metallosurfactants bis(4,4'-tridecyl-2,2'-bipyridine)-(4,4'-dicarboxy-2,2'-bipyridine) ruthenium(II)-bis(chloride) (1) and bis[2-(2,4-difluorophenyl)pyridine](4,4'-dinonadecyl-2,2'-bipyridin ...

American Chemical Society2010

Photocatalytic decomposition of acetone over dc-magnetron sputtering supported vanadia/TiO2 catalysts

Two series of titania-based photocatalysts were prepared by the sputtering method, in pure Ar atmosphere at a pressure of 0.5 Pa using a vanadium target source in a direct dc mode with a discharge of 300 V. The time of deposition was varied between 1 and 1 ...

2009

Propriétés optiques de petits agrégats de métaux nobles en matrice de néon

Sylvain Lecoultre

The optical properties of small noble metal clusters have been studied by absorption and fluorescence for sizes between 1 and 10 atoms. The experimental technique consists in depositing size-selected clusters in a neon matrix and analyzing with a spectrome ...

EPFL2009

Optical properties of annealed Mn2+-doped ZnS nanoparticles

Heinrich Hofmann, Alke Fink, Yvonne Axmann, Benedikt Steitz

Cysteine stabilized ZnS and Mn2+-doped ZnS nanoparticles were synthesized by a wet chemical route. Using the ZnS:Mn2+ nanoparticles as seeds, silica-coated ZnS (ZnS@Si) and ZnS:Mn2+ (ZnS:Mn2+@Si) nanocomposites were formed in water by hydrolysis and conden ...

2008

Enhancement and subwavelength confinement of light in plasmonic nanostructures

Holger Fischer

This work includes the fabrication of plasmonic nanostructures as well as the investigation of their optical properties in the near-field and in the farfield. As expressed in the title of this thesis the focus lies in the subwavelength confinement and enha ...

EPFL2008

Fast equilibration of silane/hydrogen plasmas in large area RF capacitive reactors monitored by optical emission spectroscopy

Laurent Fabien Hubert Sansonnens, Christoph Hollenstein, Alan Howling, Benjamin Strahm

The optimal plasma parameters for plasma processing, such as deposition of microcrystalline silicon from silane and hydrogen, are generally chosen in steady-state discharge conditions. However, this steady state must be reached in a short time after plasma ...

2007

Near-field spectroscopy and theoretical modeling of disordered semiconductor quantum wires

Andrea Feltrin

In this thesis work, we report scanning near-field optical photoluminescence spectroscopy measurements with at best 200 nm spatial resolution performed on disordered semiconductor V-groove AlGaAs/GaAs quantum wires. In order to interpret the results of the ...

EPFL2004