LSU

Laboratory of Ultrafast Spectroscopy

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Ultrafast spectroscopy with femtosecond laser and fs/ps X-ray pulses – Condensed-phase dynamics – Dynamics of Biomolecules – Photovoltaic Materials

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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.

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LSU News

May 2019

  • We published in collaboration with the University of Zürich a time-resolved 2DUV and CD study on Peptide dynamics:

“Broad-Band Ultraviolet CD Spectroscopy of Ultrafast Peptide Backbone Conformational Dynamics”

J. Phys. Chem. Lett., 2019, 10, pp 2700–2705

  • Majed Chergui won the Liversidge Award of the Royal society of chemistry for outstanding contributions to physical chemistry.

April 2019

  • We published a collaborative study on black phosporus:

“Photocarrier-induced band-gap renormalization and ultrafast charge dynamics in black phosphorus”

2D MaterialsVol 6, 3 (2019) DOI.org/10.1088/2053-1583/ab1216

March 2019

  • Our traditional winter seminar took place in Valtournenche (Italy) with many interesting talks.
  • Welcome to Anna Maron who visits our group for four months.

February 2019

  • 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

January 2019

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 BrämAndrea Cannizzo, and Majed Chergui

J. Phys. Chem. A 2019, 12371461-1468 DOI10.1021/acs.jpca.9b00007

December 2018

  • Congratulation to Dr. Thomas Rossi for the public thesis defense!

November 2018

  • 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.

October 2018

July 2018

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, 1885007-5014

DOI: 10.1021/acs.nanolett.8b01837

  • Benjamin Bauer, Tania Palmieri and Thomas Rossi presented their research as oral talks at the Ultrafast Phenomena 2018 Conference in Hamburg. Congratulations!

June 2018

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

  • New publication in PRL, also highlighted on the SB news:

Simon P. Neville, Majed Chergui, Albert Stolow, Michael S. Schuurman.

“Ultrafast X-ray spectroscopy of conical intersections”

 Physical Review Letters 120, 12 June 2018.

April 2018

  • Welcome to LSU to the new postdoc Jeremie Ruxel and the master student Kevin Jablonka!

February 2018

  • 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.

January 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.

November 2017

  • 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”.

October 2017

  • Thomas Rossi is awarded the Teaching Awards by the Chemistry and Chemical Engineering Section for his assistantship in the course “Molecular Physics”. Congratulations Thomas!

September 2017

  • Majed Chergui is giving an Inaugural Visionary Lecture at the OSA Frontiers in Optics and Laser Science meeting (Washington DC, September 2017).

August 2017

  • A new method for probing interfacial electron injection is published in JACS and featured in the EPFL SB news and on phys.org:

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. 

July 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.

June 2017

May 2017

  • 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.

April 2017

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.

January 2017

  • Congratulation to Dr. Fabio Santomauro for the public thesis defense.

Fabio G. Santomauro, Jakob Grilj, Lars Mewes, Georgian Nedelcu, Sergii YakuninThomas Rossiet 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!

December 2016

November 2016

  • 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!