LAboratoire de Spectrochimie Infrarouge et Raman – UMR 8516
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Descriptif du sujet

Metal Coin Nano-Clusters studied by ultrafast spectroscopy
Encadrement : S. Aloïse
Sujet : 

In between the worlds of inorganic nanoparticules and organic molecules, Coinage Metal Thiolate Clusters (CMTC), Mn(SR)m  (M = Cu, Ag, Au), with a size less than 10 nm, are novel fascinating nano-objects for their unique properties of photoluminescence with various applications in modern science (bio-sensing, bio-imaging, photocatalysis, photonics, and molecular electronics). A CMTC structure, represented below, consists of a purely metallic core surrounded by a metal/sulfur shell on which various types of thiolate substituents can be grafted (the latter being responsible for the overall chemical stability). Due to the enhanced quantum confinement, these hybrid systems exhibit molecule-like optical transitions while the typical nanoparticle plasmon features vanish. As an evidence, the photochemistry of CMTC has attracted the attention of worldwide scientific groups who reported unexpected results, such as dual emission, high triplet quantum yield, wavelength excitation effect ….

During his(her) Ph-D inside LASIR laboratory, the student will study a set of novel CMTC to answer several fundamental photochemical questions. To undertake such study, the candidate will have access to various ultrafast absorption spectroscopic systems (pump-probe experiments) allowing to cover different reaction times from femtoseconds to milliseconds. In particular, after deriving the main photochemical pathways, he/she will have to determine the role played by the atomic core, the metal/sulfur corona, the organic thiolate moieties. Depending on his/her findings and feeling, the Ph-D will have the possibility to make the project evolve toward photovoltaic systems (interaction with TiO2 particles), photodynamic therapy (interaction with O2), or photocatalytic systems. Microsoft Word – PhDproposal_ 2018_CMTC_Eng-Aloise