Publications de Gerald Auböck

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

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

Clocking the Ultrafast Electron Cooling in Anatase Titanium Dioxide Nanoparticles

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

2018

Vibrational coherence transfer in the ultrafast intersystem crossing of a diplatinum complex in solution

Majed Chergui, Ivano Tavernelli, Gerald Auböck, Roberto Monni, Gloria Capano

National Academy of Sciences2018

Photoaquation Mechanism of Hexacyanoferrate(II) Ions: Ultrafast 2D UV and Transient Visible and IR Spectroscopies

Majed Chergui, Gerald Auböck, Marco Eli Reinhard, Thomas James Penfold, Raphaël Horváth

Ferrous iron(II) hexacyanide in aqueous solutions is known to undergo photoionization and photoaquation reactions depending on the excitation wavelength. To investigate this wavelength dependence, we implemented ultrafast two-dimensional UV transient absor ...

American Chemical Society2017

Conservation of vibrational coherence in ultrafast electronic relaxation: The case of diplatinum complexes in solution

Majed Chergui, Gerald Auböck, Roberto Monni, Kathrin Maria Aziz-Lange, Dominik Kinschel

We report the results of ultrafast transient absorption studies of tetrakis(l-pyrophosphito) diplatinate(II), Pt-2(mu-P(2)O(5)H2)(4) (Pt(pop)) and its perfluoroborated derivative Pt-2(mu-P2O5(BF2)(4) (Pt(pop-BF2)) in water and acetonitrile upon e ...

Elsevier2017

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

Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature

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

Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of deep- ...

2017

Sub-50-fs photoinduced spin crossover in [Fe(bpy)(3)](2+)

Majed Chergui, Gerald Auböck

It is known that excitation by visible light of the singlet metal-to-ligand charge-transfer (1MLCT) states of Fe(II) complexes leads to population of the lowest-lying high-spin quintet state (T-5) with unity quantum yield. Here we investigate this so-calle ...

Nature Publishing Group2015

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

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

A cascade through spin states in the ultrafast haem relaxation of met-myoglobin

Majed Chergui, Olivier Christian Bräm, Frank van Mourik, Cristina Consani, Gerald Auböck

We report on a study of the early relaxation processes of met-Myoglobin in aqueous solution, using a combination of ultrafast broadband fluorescence detection and transient absorption with a broad UV-visible continuum probe at different pump energies. Reco ...

American Institute of Physics2014

Ultrafast Tryptophan-to-Heme Electron Transfer in Myoglobins Revealed by UV 2D Spectroscopy

Majed Chergui, Frank van Mourik, Cristina Consani, Gerald Auböck

Tryptophan is commonly used to study protein structure and dynamics, such as protein folding, as a donor in fluorescence resonant energy transfer (FRET) studies. By using ultra-broadband ultrafast two-dimensional (2D) spectroscopy in the ultraviolet (UV) a ...

American Association for the Advancement of Science2013

Ultrabroadband femtosecond two-dimensional ultraviolet transient absorption

Majed Chergui, Frank van Mourik, Cristina Consani, Gerald Auböck

We present a broadband two-dimensional transient absorption setup for the UV around 300 nm with a time resolution of 150 fs. A narrowband, frequency tunable pump pulse and a broadband probe pulse are generated from the output of a noncollinear optical para ...

Optical Society of America2012

Femtosecond pump/supercontinuum-probe setup with 20 kHz repetition rate

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Cristina Consani, Gerald Auböck, Roberto Monni

We developed a fast multichannel detection system for pump-probe spectroscopy, capable of detecting single shot super-continuum spectra at the repetition rate (10-50 kHz) of an amplified femtosecond laser system. By tandem pumping the amplifier with three ...

Amer Inst Physics2012

Femtosecond carrier dynamics in bulk graphite and graphene paper

Majed Chergui, Frank van Mourik, Andrea Cannizzo, Gerald Auböck, Fabrizio Carbone

Femtosecond white-light continuum probe transient absorption and reflectivity measurements of bulk graphite and graphene paper are reported. In graphite, the relaxation of photoinduced electron–hole pairs happens through in-plane electron–electron and elec ...

Elsevier2011

Ultrafast (Bio)physical and (Bio)chemical Dynamics

Majed Chergui, Olivier Christian Bräm, Frank van Mourik, Amal El Nahhas, Andrea Cannizzo, Ahmad Ajdar Zadeh Oskouei, Renske Marjan van der Veen, Cristina Consani, Gerald Auböck

We give an overview of our recent work on ultrafast dynamics of chemical (organic dyes, metal-complexes, colloidal quantum dots), and biological (retinal and haem proteins) systems in the liquid phase, studied with a variety of ultrafast optical techniques ...

2011

Multiphoton-Excited Luminescent Lanthanide Bioprobes: Two- and Three-Photon Cross Sections of Dipicolinate Derivatives and Binuclear Helicates

Jean-Claude Bünzli, Majed Chergui, Anne-Sophie Chauvin, Frank van Mourik, Andrea Cannizzo, Bo Song, Gerald Auböck, Svetlana Eliseeva

Multiphoton excited luminescent properties of water-soluble EuIII and TbIII complexes with derivatives of dipicolinic acid functionalized with a polyoxyethylene pendant arm and terminal groups, [Eu(LOMe)3]3-, [Eu(LNH2)3]3-, and [Tb(LOH)3]3-, as well as of ...

2010