Personal information
Born november 2nd 1975
Married, two children
French citizenship

Address :
Laboratoire CRM2
Boulevard des aiguillettes, BP 239
54506 Vandoeuvre-les-Nancy
Tel. 03-72-74-56-34
Email : sebastien.pillet@univ-lorraine.fr

Professional experience
2002-… : CNRS research associate (section 5) – current situation
2000-2002 : Post doctoral fellow, Chemistry department at University of New York in Buffalo (Pr. Philip Coppens’s lab)

Education
2024 : Habilitation Thesis                                                                        Univ. de Lorraine
2001 : PhD thesis Physics                                                                         Univ. Henri Poincaré Nancy-I
1998 : DEA Physics and chemistry of Matter and Materials              Univ. Henri Poincaré Nancy-I

Responsabilities

• 2017-… : Manager of the CRISP team – Cristallographie et Relations Structure Propriétés
• 2021-… : Member of the governing board of the GdR CNRS « Pérovskites Hybrides Halogénées »
• 2016-2020 : Deputy director of the GdR CNRS « Magnétisme et Commutation Moléculaire »
• 2017-2022 : Participation to the PRC3 program commitee of the SOLEIL synchrotron
• 2017-2021, puis 2021-… : Elected member of the governing board and treasurer of the Association Française de Cristallographie
• 2015-… : Treasurer of the Lorraine section of the Société Française de Physique
• 2013-2014 : Mission manager « année internationale de la cristallographie » at CNRS Institut de Physique
• 2019 : chairman of the congress Rayons X et Matière (Nancy)
• 2024 : organization of the thematic school 2024 « Metal Halide Perovskites for Optoelectronics : from Fundamental to Devices » in Roscoff october 6-11^th 2024 (https://hpero-2024.sciencesconf.org/)

Advisor

PhD thesis: 8 co-supervision

• 2002-2005 : Vincent Legrand (co-supervision 50 %, dir. C. Lecomte and S. Pillet, MENRT grant), defended on november 18^th
  Photocrystallography, methodology and application to the determination of the electron density of spin transition complexes

• 2005-2008 : William Nicolazzi (co-supervision 50 %, dir. C. Lecomte and S. Pillet, MENRT grant), defended on november 27^th
  Numerical modeling of photo-induced phase transition

• 2008-2011 : Dorothéa Mader (co-supervision 50 %, dir. C. Lecomte and S. Pillet, MENRT grant), defended on november 14^th
  Structure-properties relationship in spin transition materials : nanostructuring and dilution of the metallic cation

• 2013-2017 : Nicolas Casaretto (co-supervision 50 %, dir. D. Schaniel and S. Pillet, MENRT grant), defended on October 25^th
  Structural dynamics from stationnary and time resolved photocrystallography : instrumental development and application to photoisomerisable molecular materials

• 2016-2019 : Samuel Ahoulou (co-supervision 50 %, dir. N. Vila – LCPME and S. Pillet, MENRT grant), defended on December 19^th
  Formatting and study of photo- and redox-active complexes confined in organized and vertically aligned silica thin film

• 2019-2022 : Asma Hasil (co-supervision 50 %, dir. D. Schaniel and S. Pillet, Region Grand Est grant), defended on December 13^th
  Structural dynamics of photoswitchable complexes : from seconds to femtoseconds

• 2023-… Samuel Mathieu (co-supervision 50 %, dir. M. Stoffel-IJL and S. Pillet, Lorraine Université d’Excellence grant)
  Chiral hybrid perovskites for spin-LEDs : from crystal growth to component

• 2024-… Aser Garcia Beamud (co-supervision 50 %, dir. Pillet and E. Tailleur, pôle CPM grant)
  Ferroelectric semiconductor hybrid perovskites for optoelectronics : from synthesis to physical properties

Post-doc fellows : 3 supervisions

• 2012-2013 : Pascal Parois (ANR CROSS-NANOMAT grant)
  Development of software interfaces for time-resolved X-ray diffraction

• 2015-2016 : Bertrand Fournier (ANR BISTA-MAT grant)
  Data analysis of nanobeam X-ray diffraction and PDF data analysis

• 2021-2022 : Krzyzstof Konieczny (ANR MolCoSM grant)
  Set up of a time-resolved X-ray diffraction experiment coupled to photo-luminescence

Research grants

• DYNA-STRU-FERRO (projet tremplin INP CNRS 2021, PI : S. Pillet)
  Structural dynamics in ferroelectric molecular crystals from time-resolved X-ray diffraction under electric field

• MAPLUM (région Grand-Est – post-doc grant 2021-2022, PI : S. Pillet)
  Photo-magnetic luminescent materials for molecular electronics

• CHIRA-PERO-LED (Lorraine Université d’Excellence – doctoral fellowship 2023-2026, PI : S. Pillet) – partner M. Stoffel (IJL, Nancy Université)
  Chiral hybrid perovskites for spin-LEDs : from crystal growth to device

• PHC Orchid France-Taiwan (2005-2006, PI : S. Pillet, partner Y. Wang, National Taiwan University)
  Optical switching of photoactive molecular materials: experimental studies and theoretical modeling

• PHC Orchid France-Taiwan (2003-2004, PI : S. Pillet, partner Y. Wang, National Taiwan University)
  Theoretical and experimental study of photo-induced properties of molecular magnetic materials

• FASTSWITCH (ANR 2005-2008, – PI : Hervé Cailleau, IPR, Rennes) – partners : H. Cailleau (IPR – Rennes), E. Freysz (CPMOH – Bordeaux), J ;6. Létard ( ICMCB – Bordeaux), A. Bousseksou (LCC – Toulouse), C. Lecomte (CRM2)
  Photo-induced phase transitions : towards ultra-fast switching in molecular materials

• CEDA (ANR 2007-2011, PI : Michel Gillet, Ecole Centrale Paris) – partners : M. Souhassou (CRM2 – Nancy), B. Gillon (LLB – Saclay), D. Luneau (LMI – Lyon), J.-M. Gillet (SPMS – Gif sur Yvette)
  Convergence of Electron spin, charge and momentum Densities Analysis

• THEOEXP07 (ANR 2007-2010, PI : Michel Etienne, LCC, Toulouse) – partners : M. Etienne (LCC – Toulouse), C. Lecomte (CRM2)
  Understanding of agostic C-C interactions from a combined theory-experiment modeling of the electron density

• CROSS-NANOMAT (ANR 2010-2013, PI : Azzedine Bousseksou, LCC, Toulouse) –partners : S. Pillet (CRM2), A. Bousseksou (LCC – Toulouse), Y. Guari (Univ. Montpellier), G. Bouzerar (Institut Neel – Grenoble)
  Bistable molecular nanomaterials

• BISTA-MAT (ANR 2013-2017, porteur Smail Triki, CEMCA, Brest) – partenaires : S. Pillet (CRM2), S. Triki (CEMCA – Brest), K. Boukheddaden (GEMAC – Versailles), G. Chastanet (ICMCB – Bordeaux)
  Magnetic bistability in new molecular systems built from anionic bridging ligands

• MolCoSM (ANR 2021-2024, PI : Smail Triki, CEMCA, Brest) – partners : S. Pillet (CRM2), S. Triki (CEMCA – Brest), K. Boukheddaden (GEMAC – Versailles),
  From Molecular Complexes to Synergic Multi-Switchable Fluorescent Solids

• STRUDYN (ANRI 2022-2024, PI : Dominik Schaniel, CRM2) – partners : D. Schaniel (CRM2), G. Kostin (NIIC – Russie)
  Structural dynamics of photoswitchable solids

• MolBaroFrige (ANR 2024-2028, PI : P. Rosa, ICMCB) – partners : E.-E. Bendeif (CRM2), P. Rosa (ICMCB – Bordeaux), F. Giovanelli (GREMAN – Tours)
  Study and sintering of MOLecular compounds for BAROcaloric reFRIGEration

• MAGDEN (ANR 2025-2028, ANR, PI : V. Marvaud, IPCM –Paris) – partners : V. Marvaud (IPCM-Paris), S. Pillet (CRM2), J.L. Cantin (INSP-Paris)
  Conception and study of magnetic dendrimers

• FROSTBIT : First Regenerative Solid-State Barocaloric Refrigerator (2024-2028, Européen pathfinder grant, PI : P. Rosa, ICMCB, Bordeaux) – partners P. Rosa (ICMCB-Bordeaux), E.-E. Bendeif (CRM2), F. Giovannelli (GREMAN-Tours), H. Shepherd (Univ. Kent), J. Kovac (Univ. Ljubljana), P. Lloveras (Univ. Barcelone), TotalEnergies.

• General context

The major challenge in condensed matter science consists in designing and developing crystalline systems whose physical and/or chemical properties are ultimately controlled. In this context, molecular-based materials occupy a special place. It is possible, by exploiting the different degrees of freedom such as charge, spin or structure, to obtain materials with remarkable optical, magnetic, conductive, dielectric, elastic, etc. behaviors whose complexity relies on strong coupling between microscopic degrees of freedom; the crystallographic structure plays a crucial role in the orchestration of these interactions. My research activity focuses on the structure-property relationships of switchable and/or photosensitive functional materials with the objective of achieving an engineering of the structure and crystal symmetry using light to control the resulting physical properties.

• Photo-induced molecular processes

Molecular materials offer beautiful examples of the control of magnetic, structural or electronic properties by light. The use of ultra-short laser pulses leads to new non-equilibrium physics where structural order parameters are in general strongly coupled to spin and electronic order parameters. The study of the fundamental mechanisms driving these photo-induced phase transformations or transitions requires precisely monitoring the structural modifications and their dynamics on multiple time scales, and covering all spatial scales from the atom to the macroscopic scale. My objective in this context is to achieve an understanding of the influence of structure and structural dynamics on physical properties in photoisomerizable, photomagnetic or photostrictive systems. My objects of study are photomagnetic molecular magnets, spin transition materials, or nitrosyl molecular complexes

• Photo-induced self-organization processes

Photo-induced self-organization mechanisms in the solid state result from a competition between photoswitching at the molecular scale, ferroelastic interactions within the crystalline solid and relaxation processes. This competition gives rise to highly cooperative and nonlinear processes in the solid state that can be controlled in certain cases by light. My studies focus on photo-induced commensurable and incommensurable phase transitions, as well as heterogeneous nucleation and domain growth mechanisms associated with first-order phase transitions. Photo-induced multistability phenomena have been demonstrated in some spin transition materials.

• Electron density of photo-induced metastable states

Photocrystallographic studies are relevant and extremely important for elucidating photo-induced mechanisms, by following the structural reorganizations induced at the molecular scale. As stated by the theorem of Hohenberg and Kohn, beyond the structure, the electron density of the ground state of the system ρ(r ⃗ )=ψ(r ⃗ )∙ψ^* (r ⃗ ) is considered as the function fully determining the average values of all observables, especially energy. A precise mapping of this non-equilibrium electron redistribution as a function of time ρ(r ⃗,t) can provide important information on photo-induced mechanisms. I set up a methodology and instrumentation to deduce the electron density of photoinduced metastable states using as a model system two spin transition complexes Fe(phen)2(NCS)2 and [Fe(btr)2( NCS)2].H2O., which opens numerous perspectives for the study of fundamental mechanisms in switchable solids.

• Halide hybrid perovskites

Halide organic-inorganic hybrid compounds are new emerging semiconductors, consisting of an inorganic structural framework into which organic cations are inserted. The coupling between organic insulating and inorganic semiconductor components gives rise to remarkable electronic and optical behaviors. Optical and electronic properties result largely from the connectivity of the inorganic framework (3D, 2D, 1D, 0D connectivity), the interaction between organic and inorganic components, and the resulting structural distortions. My contribution in this field consists of studying the fundamental relationship which links the multiscale structural organization and its dynamics to optoelectronic properties, with the long-term objective of manipulating these properties by application of an external stimulus (pressure, light, electric field, temperature). In particular, we have highlighted the role played by structural distortions in broadband emission mechanisms (white light emission).