Laboratory of Ultrafast Spectroscopy
Welcome to Laboratory of Ultrafast Spectroscopy / Laboratoire de spectroscopie ultrarapide (LSU)
The activities of our laboratory aim at a detailed description of photo-induced processes in the molecular condensed phase (liquid, solid and proteins) and in metallic and semiconductor nanostructured materials. A central approach of our group is the visualization in “real time” of the processes by means of ultrafast laser spectroscopy.
The physical phenomena we investigate include: solvation dynamics in polar media, at interfaces and within proteins, structural changes in the chromophores and the medium (be it a solvent or a protein) and the influence of local electric fields on their spectral and dynamical features. We also study the ultrafast dynamics of charge carriers in semiconductor and metallic nanostructures of different shapes and sizes.
The experimental tools we use are ultrafast picosecond and femtosecond transient absorption spectroscopy, ultrafast fluorescence up-conversion spectroscopy, photon-echo spectroscopy. We have also developed novel optical laser pump-X-ray probe techniques using picosecond and femtosecond hard X-ray pulses from a synchrotron.
- We published a collaborative study on black phosporus:
“Photocarrier-induced band-gap renormalization and ultrafast charge dynamics in black phosphorus”
- Our traditional winter seminar took place in Valtournenche (Italy) with many interesting talks.
- Welcome to Anna Maron who visits our group for four months.
- The LACUS day took place on the 28th of february.
- Congratulation to Dr. Tania Palmieri for her public thesis defense!
- Majed Chergui published an invited perspective article on “Ultrafast molecular photophysics in the deep-ultraviolet” highlighted as editors pick:
J. Chem. Phys. 150, 070901 (2019) DOI.org/10.1063/1.5082644
- We published our work on time resolved circular dichroism in the UV in Optica highlighted on the EPFL news and the Physics World news:
Malte Oppermann, Benjamin Bauer, Thomas Rossi, Francesco Zinna, Jan Helbing, Jérôme Lacour, and Majed Chergui
“Ultrafast broadband circular dichroism in the deep ultraviolet”
Optica Vol. 6, Issue 1 ,pp. 56-60(2019) DOI: 10.1364/OPTICA.6.000056
- New study about x-ray transient grating spectroscopy got published in optics letters:
Opt. Lett. Vol. 44, Issue 3, pp. 574-577 (2019) DOI.org/10.1364/OL.44.000574
- We published our work on Fluorescence Up-conversion on Metalloporphyrins:
Olivier Bräm, Andrea Cannizzo, and Majed Chergui
J. Phys. Chem. A 2019, 123, 7, 1461-1468 DOI: 10.1021/acs.jpca.9b00007
- Congratulation to Dr. Thomas Rossi for the public thesis defense!
- The “International Symposium on Ultrafast Science: From the infrared to the X-rays” organised by Majed Chergui took place from November 28-30 in Lausanne. Informations can be found at the event page as well as a gallery.
- Majed Chergui has been elected Fellow of the American Crystallographic Association:
Edoardo Baldini, Tania Palmieri, Adriel Dominiguez, Pascal Ruello, Angel Rubio, Majed Chergui.
“Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2 Nanoparticles”
Nano Lett. 2018, 18, 8, 5007-5014
- Benjamin Bauer, Tania Palmieri and Thomas Rossi presented their research as oral talks at the Ultrafast Phenomena 2018 Conference in Hamburg. Congratulations!
Roberto Monni, Gloria Capano, Gerald Auböck, Harry B. Gray, Antonín Vlcek, Ivano Tavernelli, Majed Chergui.
“Vibrational coherence transfer in the ultrafast intersystem crossing of a di-platinum complex in solution.”
PNAS 25 June 2018. DOI: 10.1073/pnas.1719899115
Simon P. Neville, Majed Chergui, Albert Stolow, Michael S. Schuurman.
“Ultrafast X-ray spectroscopy of conical intersections”
Physical Review Letters 120, 12 June 2018.
- The PhD Thesis of former student Edoardo Baldini “Nonequilibrium Dynamics of Collective Excitations in Quantum Materials” is now published as a book by Springer Nature. The book is part of the series “Springer Theses – The best of the best” for outstanding research in the Natural Sciences!
- Welcome to LSU to the new postdoc Jeremie Ruxel and the master student Kevin Jablonka!
- Majed Chergui has been elected Foreign Member of the Royal Spanish Academy of Sciences (Real Academia de Ciencias). The achievement is highlighted in the EPFL SB news.
- Our X-ray study of hole trapping in ZnO is published in Nature Communication! Read the press on SB news:Thomas J. Penfold, Jakub Szlachetko, Fabio G. Santomauro, Alexander Britz, Wojciech Gawelda, Gilles Doumy, Anne Marie March, Stephen H. Southworth, Jochen Rittmann, Rafael Abela, Majed Chergui & Christopher J. Milne.”Revealing hole trapping in zinc oxide nanoparticles by time-resolved X-ray spectroscopy”Nature Communications 02 February 2018.
- In TiO2, electron cooling in the conduction band occurs in less than 50 fs! Read our new article published on ACS Photonicsand highlighted on EPFL SB news:
Edoardo Baldini, Tania Palmieri, Enrico Pomarico, Gerald Auböck, and Majed Chergui
“Clocking the Ultrafast Electron Cooling in Anatase Titanium Dioxide Nanoparticles.”
ACS Photonics 11January 2018.
- The 24th issue of the Laserlab Newsletter “LASERLAB Forum” is published featuring an article by Edoardo Baldini and Majed Chergui (LSU) on the absorption of light by titanium dioxide.
- Majed Chergui is the keynote speaker of the 78th “Sir Jesse Boot Lecture” at the University of Nottingham, where he will talk about “Ultrafast Chemical Dynamics in Solution: Optical and X-ray studies”.
- Thomas Rossi is awarded the Teaching Awards by the Chemistry and Chemical Engineering Section for his assistantship in the course “Molecular Physics”. Congratulations Thomas!
- Majed Chergui is giving an Inaugural Visionary Lecture at the OSA Frontiers in Optics and Laser Science meeting (Washington DC, September 2017).
Congratulations to Dr. Edoardo Baldini is awarded a 2017 Chorafas Prize “for outstanding work in selected fields in the engineering sciences, medicine and the natural sciences” related to his doctoral thesis.
Edoardo Baldini, Tania Palmieri, Thomas Rossi, Oppermann, Enrico Pomarico, Gerald Auböck, and Majed Chergui
“Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature.”
JACS, web publication on August 1, 2017.
E. Baldini, A. Dominguez, L. Chiodo, E. Sheveleva, M. Yazdi-Rizi, C. Bernhard, A. Rubio, and M. Chergui.
“Anomalous anisotropic exciton temperature dependence in rutile TiO2.”
Physical Review B 96, 2017.
- Three new postdocs join LSU: Thomas Barillot, Giulia Mancini and Michele Puppin. Welcome to the group!
- This month’s issue of CHIMIA is entirely dedicated to LACUS and features a collection of articles presenting the capabilities of this facility, incuding our Harmonium and LOUVRE laboratories.
- Our study on excitons in anatase TiO2 is published in Nature Communication and is featured on the EPFL homepage and on phys.org.
E. Baldini, L. Chiodo, A. Dominguez, M. Palummo, S. Moser, M. Yazdi-Rizi, G. Auböck, B.P.P. Mallett, H. Berger, A. Magrez, C. Bernhard, M. Grioni, A. Rubio, M. Chergui.
“Strongly bound excitons in anatase TiO2 single crystals and nanoparticles.”
Nature Communications 8(13), 2017.
- Congratulation to Dr. Fabio Santomauro for the public thesis defense.
- Our X-ray study on Cs-lead halide perovskite nanocrystals is published in Structural dynamics and is featured in Physics Today.
Fabio G. Santomauro, Jakob Grilj, Lars Mewes, Georgian Nedelcu, Sergii Yakunin, Thomas Rossi, et al.
“Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy.”
Structural Dynamics 4, 2017.
- Congratulation to Dr. Edoardo Baldini for your public PhD thesis defense!
- Welcome to the new PhD student Sorokin Boris!
- Congratulations to Edoardo Baldini, who is awarded an Early Postdoc Mobility fellowship from the SNSF.
- Tania Palmieri is awarded the 1st prize for the “Flash Presentation” at the EPFL Photonics Day, for presenting the poster “Ultrafast exciton dynamics in CH3NH3PbBr3 single crystals” in 180 seconds. Well done!