Objectif Transition metal (TM) oxides (TiO2, ZnO, NiO) are large gap insulators that have emerged as highly attractive materials over the past two decades for applications in photocatalysis, solar energy conversion, etc., all of which rely on the generation of charge carriers, their evolution and their eventual trapping at defects or a self-trapped excitons. Despite the huge interest for such materials, the very nature of the elementary electronic excitations (Frenkel, Wannier or charge transfer exciton) is still not established, nor is the way these excitations evolve after being created: excitonic polaron or charged polaron. Finally, the electron and hole recombine is also not clearly established because of issue of defects and trapping. In order to tackle these issues, here we implement novel experimental tools that would provide us with hitherto inaccessible information about the charge carrier dynamics in TM oxides. Of importance is the ability to detect both the electrons and the holes. Some of these tools have been developed in the PI’s group: i) Ultrafast X-ray absorption spectroscopy (XAS) will provide information about the final metal d-orbitals and about the structural changes around it; ii) Ultrafast X-ray emission (XES) will provide information about hole states. While these two approaches are ideal element-selective ones, the localization of the electron at metal atoms represents a small proportion of the electron population. Therefore, ultrafast Angle-resolved photoemission spectroscopy (ARPES) will be used to map out the band structure changes in the system and the evolution of the conduction band electrons. Ultrafast 2-dimensional (2D) UV (<400nm) transient absorption spectroscopy allows the mapping of the time evolution of both the valence and the conduction bands by its ability to pump and probe above the band gap. Last, Fourier Transform visible 2D spectroscopy will allow the probing of gap state dynamics at high time resolution. Champ scientifique natural scienceschemical sciencescatalysisphotocatalysisnatural scienceschemical sciencesinorganic chemistryinorganic compoundsnatural scienceschemical sciencesinorganic chemistrytransition metalsnatural sciencesphysical sciencesatomic physicsnatural sciencesphysical sciencesopticsspectroscopyabsorption spectroscopy Mots‑clés electrons holes band structure charge trapping surfaces Titanium dioxide Zinc Oxide Nickel Oxide nanoparticles single crystals Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Thème(s) ERC-ADG-2015 - ERC Advanced Grant Appel à propositions ERC-2015-AdG Voir d’autres projets de cet appel Régime de financement ERC-ADG - Advanced Grant Institution d’accueil ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE Contribution nette de l'UE € 2 482 305,00 Adresse BATIMENT CE 3316 STATION 1 1015 Lausanne Suisse Voir sur la carte Région Schweiz/Suisse/Svizzera Région lémanique Vaud Type d’activité Higher or Secondary Education Establishments Liens Contacter l’organisation Opens in new window Site web Opens in new window Participation aux programmes de R&I de l'UE Opens in new window Réseau de collaboration HORIZON Opens in new window Coût total € 2 482 305,00 Bénéficiaires (1) Trier par ordre alphabétique Trier par contribution nette de l'UE Tout développer Tout réduire ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE Suisse Contribution nette de l'UE € 2 482 305,00 Adresse BATIMENT CE 3316 STATION 1 1015 Lausanne Voir sur la carte Région Schweiz/Suisse/Svizzera Région lémanique Vaud Type d’activité Higher or Secondary Education Establishments Liens Contacter l’organisation Opens in new window Site web Opens in new window Participation aux programmes de R&I de l'UE Opens in new window Réseau de collaboration HORIZON Opens in new window Coût total € 2 482 305,00