emploi

The Atom Probe Tomography (APT), the laboratory's flagship technique, enables the 3D reconstruction of the chemical distribution of a nano-object, with spatial resolution close to the atomic scale, using field evaporation of ions from the surface. In laser-assisted APT, commonly used to study metals, insulators and semiconductors, evaporation is triggered by an ultrafast laser pulse in the near ultraviolet (UV) range [1-2].

Teeth are particularly fascinating due to their remarkable properties and essential role in mastication. While most dental research focuses primarily on human or mammalian teeth, the diversity of dental tissues in animals provides valuable insights for biomaterials, biomineralization, and bio-inspired designs.

Project description

This post-doctorate is part of the ANR SpinodalDesign project. It involves three French groups: the GPM (Groupe de Physique des Matériaux – UMR 6634, host laboratory for this post-doctorate), the UMET in Lille and SIMAP in Grenoble. In the framework of this project, we are developing an original way of achieving high mechanical strength by combining an ultra-fine granular structure and spinodal decomposition. The post-doctoral fellow will conduct a microstructural characterization of new high-performance alloys hardened in this way.

The search for thermoelectric materials is an active topic, and promising new families such as chalcogenides have emerged in recent years with the figure of merit ZT reaching 1 or above. One of the possible tuning parameters of ZT in chalcogenides containing transition-metal cations is magnetism which can modify the transport parameters through a modification of the band structure and/or a modification of the entropy of the material.

The objective of this thesis is to study trap phenomena in the latest generations of Gallium Nitride (GaN)-based High Electron Mobility Transistors (HEMTs). Various methods for characterizing trap behavior in GaN HEMTs exist, such as Deep Level Transient Spectroscopy (DLTS) for capacitance and current (C-DLTS and I-DLTS), Athermal Direct Current Transient Spectroscopy (A-DCTS), Deep Level Optical Spectroscopy (DLOS), Gate-Lag (GL) and Drain-Lag (DL) transient measurements, the study of transconductance frequency dispersion, S-parameter measurements, and low-frequency noise measurements.