Thermoelectric generators can convert heat directly into usable electrical energy. As they function without moving parts or working fluids thermoelectric generators require virtually no maintenance. They are therefore well-suited to increase the energy efficiency of various industrial processes or supply power in remote applications (space probes, space stations).

One material class of particular interest are the solid solutions based on Mg2Si and Mg2Sn.

While these show promising thermoelectric properties the role and influence of intrinsic defects (vacancies, interstitials, anti-sites) and extrinsic defects (e.g. due to dopants) on the thermoelectric

properties are still not fully understood and might be a lever to increase the material performance further.

The task of the PhD work would therefore be to elucidate the role of defects. In detail this will involve the calculation of formation energies for different defects in Mg2Si, Mg2Sn and the solid solutions using density functional theory (principally with the computer code VASP) and following from that the calculation of the transport properties based on the Boltzmann Transport Equations (BoltzTrap). The calculation of phase diagrams and the interaction of intrinsic and extrinsic dopants will be of further interest and will be tackled by a combined approach: CALPHAD + VASP. A strong interaction with experimentalists is required to validate the calculated results and design new experiments.

This work will also involve a very strong collaboration with the group of Prof. Jund at the Institut Charles Gerhardt in Montpellier (France) where most of the computer infrastructure is located.