Publications by Andre Al Haddad

Quantifying Photoinduced Polaronic Distortions in Inorganic Lead Halide Perovskite Nanocrystals

Majed Chergui, Giulia Fulvia Mancini, Andre Al Haddad, Thomas Charles Henry Rossi, Nicola Colonna, Dominik Kinschel, James Michael Budarz, Oliviero Cannelli, Michele Puppin, Ludmila Maria Diniz Leroy

The development of next-generation perovskite-based optoelectronic devices relies critically on the understanding of the interaction between charge carriers and the polar lattice in out-of-equilibrium conditions. While it has become increasingly evident fo ...

2021

Broadband visible two-dimensional spectroscopy of molecular dyes

Majed Chergui, Andre Al Haddad, Lars-Hendrik Mewes, Rebecca Ann Ingle

Two-dimensional Fourier transform spectroscopy is a promising technique to study ultrafast molecular dynamics. Similar to transient absorption spectroscopy, a more complete picture of the dynamics requires broadband laser pulses to observe transient change ...

AMER INST PHYSICS2021

Two-dimensional correlation analysis for x-ray photoelectron spectroscopy

Andre Al Haddad, Thomas Roland Barillot, Christoph Bostedt

X-ray photoelectron spectroscopy (XPS) measures the binding energy of core-level electrons, which are well-localised to specific atomic sites in a molecular system, providing valuable information on the local chemical environment. The technique relies on m ...

IOP Publishing2021

Shapes of rotating normal fluid He-3 versus superfluid He-4 droplets in molecular beams

Andre Al Haddad, Christoph Bostedt

Previous single-pulse extreme ultraviolet and x-ray coherent diffraction studies revealed that superfluid He-4 droplets obtained in a free jet expansion acquire sizable angular momentum, resulting in significant centrifugal distortion. Similar experiments ...

AMER PHYSICAL SOC2020

Electronic Population Transfer via Impulsive Stimulated X-Ray Raman Scattering with Attosecond Soft-X-Ray Pulses

Solène Oberli, Andre Al Haddad, Christoph Bostedt, Siqi Li, Xiang Li

Free-electron lasers provide a source of x-ray pulses short enough and intense enough to drive nonlinearities in molecular systems. Impulsive interactions driven by these x-ray pulses provide a way to create and probe valence electron motions with high tem ...

AMER PHYSICAL SOC2020

The role of transient resonances for ultra-fast imaging of single sucrose nanoclusters

Andre Al Haddad, Christoph Bostedt

Intense x-ray free-electron laser (XFEL) pulses hold great promise for imaging function in nanoscale and biological systems with atomic resolution. So far, however, the spatial resolution obtained from single shot experiments lags averaging static experime ...

Nature Research2020

Attosecond transient absorption spooktroscopy: a ghost imaging approach to ultrafast absorption spectroscopy

Andre Al Haddad, Christoph Bostedt, Jonas Knurr, Siqi Li, Zhaoheng Guo

The recent demonstration of isolated attosecond pulses from an X-ray free-electron laser (XFEL) opens the possibility for probing ultrafast electron dynamics at X-ray wavelengths. An established experimental method for probing ultrafast dynamics is X-ray t ...

ROYAL SOC CHEMISTRY2020

Micro-focused MHz pink beam for time-resolved X-ray emission spectroscopy

Andre Al Haddad, Christoph Bostedt

The full radiation from the first harmonic of a synchrotron undulator (between 5 and 12 keV) at the Advanced Photon Source is microfocused using a stack of beryllium compound refractive lenses onto a fast-moving liquid jet and overlapped with a high-repeti ...

2019

Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy

Majed Chergui, Andre Al Haddad, Lars-Hendrik Mewes, Thomas Charles Henry Rossi, Gloria Capano, Jakob Grilj, Fabio Giacomo Santomauro, Dominik Kinschel, James Michael Budarz

We report on an element-selective study of the fate of charge carriers in photoexcited inorganic CsPbBr3 and CsPb(ClBr)(3) perovskite nanocrystals in toluene solutions using time-resolved X-ray absorption spectroscopy with 80 ps time resolution. Probing th ...

Amer Inst Physics2017

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

Set-up for broadband Fourier-transform multidimensional electronic spectroscopy

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Gerald Auböck, Andre Al Haddad, José Javier Pancracio Ojeda Andara, Adrien Alexis Paul Chauvet

We present a compact passively phase-stabilized ultra-broadband 2D Fourier transform setup. A gas (argon)-filled hollow core fiber pumped by an amplified Ti:Al2O3 laser is used as a light source providing spectral range spanning from 420 to 900 nm. Sub-10- ...

Optical Society of America2015

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

Tryptophan-to-heme electron transfer in ferrous myoglobins

Majed Chergui, Frank van Mourik, Gerald Auböck, Roberto Monni, Andre Al Haddad

It was recently demonstrated that in ferric myoglobins (Mb) the fluorescence quenching of the photoexcited tryptophan 14 (*Trp(14)) residue is in part due to an electron transfer to the heme porphyrin (porph), turning it to the ferrous state. However, the ...

National Academy of Sciences2015

Photo-induced dynamics of the heme centers in cytochrome bc(1)

Majed Chergui, Frank van Mourik, Andre Al Haddad, Adrien Alexis Paul Chauvet

The ultrafast response of cytochrome bc1 is investigated for the first time, via transient absorption spectroscopy. The distinct redox potentials of both c(1)- and b-hemes allow for a clear differentiation of their respective signals. We find that while th ...

Royal Society of Chemistry2015