Arnaud Demortière Email & Phone Number

Amiens, Fr

Amiens Area, France

My research topics focus on the development of new methods to monitor electrochemical reactions inside battery using DeepLearning algorithms.

Improving our understanding of Li ion battery cathode materials by carrying out correlated microstructural and electrochemical characterization on single, small particles. The work will include scanning electron microscope-based studies, transmission electron microscope-based studies, and x-ray based studies.

Greater Chicago Area

Luminescence Solar Concentrators : NanoRods CdSe/CdSSemiconductor core/shell colloidal nanocrystals (NCs) are promising materials for many applications such as luminescent solar concentrators (LSC), lasing media and biological labels, due to their high PL quantum yield (up to 80%), weak re-absorption and good photo-stability. Here, we focus on both the elaboration and the study of optical properties of CdSe/CdS core/shell NCs emitting between 500 and 700 nm for LSC devices in photovoltaic (PV) applications. Compare to bare PV cell, the advantage of LSC is that they collect both direct and diffuse sunlight with equal efficiency and deliver concentrated light onto the edge-mounted solar cell. Rod-shaped CdSe/CdS core/shell NCs have been synthesized by colloidal chemical approach via epitaxial process, which gives us a good control of both the CdSe core size and CdS shell thickness. This fine-tuning allows us to tune the effective core/shell band alignment, which impacts the electron and hole delocalization into the nanorods.The change of the PL quantum yield and PL lifetimes has been studied as a function of the core and shell sizes. High PL quantum yields of up to 80% have been obtained for a shell-excitationwavelength of450nm with a large quasi-Stokes shift (~100nm) that reduces the re-absorption significantly. We investigated also the photophysical properties of these semiconductor hetero-nanocrystals by time-resolved PL and transient absorption measurements, which indicate no significant trapping of electrons or holes. The hole is localized into the CdSe core within 10ps, with a transfer rate that is independent of the size of the shell, and the electron remains delocalized in the CdS shell. Radiative decay rates have been correlated with the rod volume regardless of the CdSe core size.

(1) The study of the functionnalization of Fe3O4 magnetic nanoparticles by mesogenic ligands: synthesis, purification and analysis of the core-shell hybrids, mesogenic and magnetic behaviors (nematic-like, spin canting).(2) The study of the synthesis and the physical properties of iron oxide nanocrystals: size and shape effects.

Ville De Paris, Île-De-France, France

Magnetic properties - nano materials - electron microscopy

Thèse De Doctorat, Physics

Doctor, Nanomaterials

Activities and Societies: CoPt alloy nanocrystals and Pt Nanocubes : Synthesis, Structural and Magnetic properties, Self-organization..

Masters, Physics