Theoretical Study of Thermoelectric Antimonides for Very High Temperature Applications

With the development of powerful methods to compute the electronic band structure of solids and the increasing complexity of the formulations of advanced thermoelectric materials such as those targeted in this project, quantum chemical calculations based on density functional theory (DFT) are necessary tools for the optimization of thermoelectric material properties. DFT programs embedding the most advanced approximation of the exchange-correlation functionals and considering relativistic effects will be employed to calculate the electronic structures required to use a band engineering approach for the optimization of the thermoelectric properties of the studied materials. More specifically, collected data from experiments (LINK, CRISMAT) will be used to provide significant insights to explain and understand the electrical properties of the new synthesized materials, as well as to predict how the selected structures/compositions can form ideal candidates for thermoelectricity.

To gain further information in the electronic transport properties, Boltzmann transport theory will be combined with band structure calculations assuming a constant relaxation time. Vibrational properties (low-energy phonon band structures, Grüneisen parameters) will also be studied using the density functional perturbation theory in order to gain some information on the thermal conductivity. The theoretical results, which will be gleaned, should demonstrate a complete feedback loop with theory guiding material synthesis and experiments for testing predictions, and theory refined by the experimental results.

The PhD project will start in Fall 2020 in Rennes (France). A stay at NIMS, Tsukuba (Japan) is envisioned (for few months). Applications are already open and candidates shall contact R. Gautier (rgautier@ensc-rennes.fr) with a CV and a motivation letter.