Publications associées à Subpicosecond near-infrared fluorescence upconversion study of relaxation processes in PbSe quantum dots

Resonant Tip-Enhanced Raman Spectroscopy of a Single-Molecule Kondo System

Tip-enhanced Raman spectroscopy (TERS) under ultrahigh vacuum and cryogenic conditions enables exploration of the relations between the adsorption geometry, electronic state, and vibrational fingerprints of individual molecules. TERS capability of reflecti ...

Amer Chemical Soc2024

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

Ultrafast Intersystem Crossing and Structural Dynamics of [Pt(ppy)(mu-(t)Bu(2)pz)](2)

Majed Chergui, Lars-Hendrik Mewes, Rebecca Ann Ingle

Intersystem crossing (ISC) rates of transition-metal complexes are determined by the complex interplay of a molecule's electronic and structural dynamics. To broaden our understanding of these key factors, we investigate the case of the prototypical d(8)-d ...

2020

Incidence of Quantum Confinement on Dark Triplet Excitons in Carbon Nanotubes

Ferenc Simon

The photophysics of single-wall carbon nanotubes (SWCNTs) is intensively studied due to their potential application in light harvesting and optoelectronics. Excited states of SWCNTs form strongly bound electron-hole pairs, excitons, of which only singlet e ...

2020

Ultrafast Photoelectron and Optical Spectroscopies of Photoinduced Processes in Molecular Systems in Solution

Luca Longetti

Investigating molecular excitations with femtosecond time resolution is of pivotal importance to understand the out-of-equilibrium processes taking place in molecular systems upon light absorption. The photochemistry of solvated species is heavily determin ...

EPFL2020

Direct Observation of Shallow Trap States in Thermal Equilibrium with Band‐Edge Excitons in Strongly Confined CsPbBr 3 Perovskite Nanoplatelets

Jacques-Edouard Moser, Etienne Christophe Socie, Andrés Burgos Caminal, Brener Rodrigo De Carvalho Vale

Lead halide perovskites exhibit great potential for light-emitting devices. Enhanced photoluminescence (PL) is obtained in perovskite materials of reduced dimensionalities due to the large exciton binding energy. However, as the nanocrystal size is reduced ...

2021

Spin-dependent charge transfer at chiral electrodes probed by magnetic resonance

Jean-Philippe Ansermet, Christophe Roussel, Felix Blumenschein, Mika Antero Tamski

Chirality-induced spin selectivity is evidenced by exciting the spin resonance of radicals in an electrochemical cell where the working electrode is covered with a chiral self-assembled monolayer. Because the electron transfer to and from the paramagnetic ...

ROYAL SOC CHEMISTRY2020

Excited-state band mapping and momentum-resolved ultrafast population dynamics in In/Si(111) nanowires investigated with XUV-based time- and angle-resolved photoemission spectroscopy

Michele Puppin, Matthias Wolf

We investigate the excited state electronic structure of the model phase transition system In/Si(111) using femtosecond time-and angle-resolved photoemission spectroscopy (trARPES). An extreme ultraviolet 500 kHz laser source at 21.7 eV is utilized both to ...

AMER PHYSICAL SOC2019

Efficient intersystem crossing in 2-aminopurine riboside probed by femtosecond time-resolved transient vibrational absorption spectroscopy

Rebecca Ann Ingle, Hugo Jean Baptiste Marroux

The photophysical dynamics of 2-aminopurine riboside (2APr) in CHCl3 have been studied following excitation at (pump) = 310 nm by means of femtosecond transient vibrational absorption spectroscopy (TVAS) aided by quantum chemical density functional theory ...

ROYAL SOC CHEMISTRY2018

Simulating Energy Relaxation in Pump-Probe Vibrational Spectroscopy of Hydrogen-Bonded Liquids

Michele Ceriotti

We introduce a nonequilibrium molecular dynamics simulation approach, based on the generalized Langevin equation, to study vibrational energy relaxation in pump probe spectroscopy. A colored noise thermostat is used to selectively excite a set of vibration ...

Amer Chemical Soc2017

Spin transport in topological insulator-based nanostructures

Kristina Vaklinova

With the advent of spintronics, significant research effort is made to realize efficient injection, transport, manipulation, and detection of spin. The material platforms and device architectures suitable for this purpose 3D topological insulators (TIs) ar ...

EPFL2017

Investigations of the non-adiabatic photophysics of Cu(I)-phenanthroline complexes

Gloria Capano

Cu(I)-phenanthrolines are an important class of metal-organic molecules that exhibits much promise for solar energy harvesting and solar-driven catalysis applications. Although many experimental studies have been performed calling for high-level simulation ...

EPFL2016

Photo-induced oxidation of the uniquely liganded heme f in the cytochrome b(6)f complex of oxygenic photosynthesis

Frank van Mourik, Rachna Agarwal, Andre Al Haddad, Adrien Alexis Paul Chauvet

The ultrafast behavior of the ferrous heme f from the cytochrome b(6)f complex of oxygenic photosynthesis is revealed by means of transient absorption spectroscopy. Benefiting from the use of microfluidic technologies for handling the sample as well as fro ...

Royal Society of Chemistry2016

Room temperature manipulation of long lifetime spins in metallic-like carbon nanospheres

László Forró, Bálint Náfrádi

The time-window for processing electron spin information (spintronics) in solid-state quantum electronic devices is determined by the spin-lattice and spin-spin relaxation times of electrons. Minimizing the effects of spin-orbit coupling and the local magn ...

Nature Publishing Group2016

Atomic Scale Observation of Chemical and Electronic Properties of Metal-Oxide Surfaces

Christian Alexander Stephan Dette

To meet the future global energy demand - an estimated additional 10 terawatts (TWs) per year in 2050 - a diversification of energy sources and fuels is needed. Solar energy represents a prominent alternative energy source. An important material for these ...

EPFL2016

Molecular lanthanide single-ion magnets: from bulk to submonolayers

Jan Gui-Hyon Dreiser

Single-ion magnets (SIMs) are mononuclear molecular complexes exhibiting slow relaxation of magnetization. They are currently attracting a lot of interest because of potential applications in spintronics and quantum information processing. However, exploit ...

Institute of Physics2015

2D Fourier Transform Spectroscopy Setup and Ultrafast Dynamics of Porphyrins

Andre Al Haddad

The first section of the thesis discusses the development and implementation of a two dimensional Fourier transform spectroscopy setup, that permits the recording of electronic 2D spectra in the visible regime. A hollow core fiber was used to generate broa ...

EPFL2015

Challenges in preparing, preserving and detecting para-water in bulk: overcoming proton exchange and other hurdles

Geoffrey Bodenhausen, Sami Jannin, Aurélien Bornet, Jonas Milani, Nicola Salvi, Diego Carnevale, Roberto Buratto, Daniele Mammoli, Estel Canet Martinez

Para-water is an analogue of para-hydrogen, where the two proton spins are in a quantum state that is antisymmetric under permutation, also known as singlet state. The populations of the nuclear spin states in para-water are believed to have long lifetimes ...

Royal Society of Chemistry2015

Ultrafast electronic and vibrational relaxations in mixed-ligand dithione-dithiolato Ni, Pd, and Pt complexes

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Ahmad Odeh

Ultrafast excited-state dynamics of planar Pt, Pd, and Ni dithione-dithiolato complexes were investigated by transient absorption spectroscopy on the femtosecond-picosecond timescale. All studied complexes show a common photobehaviour, although individual ...

Royal Society of Chemistry2014

Spin processes and charge dynamics in organic light emitting diodes

Francesco Comandè

In this thesis work we explore spin dependent processes and charge dynamics in α-NPD/Alq₃ based LEDs. Studies on polymer light emitting diodes based on PFO, which are fabricated by us, are also reported. Our objective is to shed light on the fundamental me ...

EPFL2014