Non-parabolic Effects Applied to Thermoelectric materials

The project is motivated by that new materials are imporrtant for a sustainable technological evolution. We address here thermoelectrical materials. Used as a thermoelec generator and converting waste heat from an industial process directly to electric engy, it will have a large effect on the energy efficiency. In the project we test out new theoretical ideas for improving efficiency of materials using new theoretical calculatiions and experiments. The exploration in the project is ground breaking on particulars of electron structure for thermoelectrical materials. Materials have been built up by atoms in crystal structures that control the allowed states and transitions. We have collaborated with the University of Vienna and published computer algorithms for theoretical transport calculations forf electrons and phonons in materials using the electron structure from the first principle calculations in VASP. We continue work on integration with large databases. We have synthesized Heusler (full and half) materials and materials with sharp changes in electronic structure giving additional energy bands with non-parabolic band structure. We have measured transport and electron phonon interactions, measured electron bands by angular resolved photo electron spectroscopy. We have demonstrated how to utilize non-parabolic bands in practical thermoelectric materials to reduce energy loss in contacts. We have also as observed that the strategy can yield materials with properties suitable for other sustainability purposes as catalyzers in processes. We have also observed that composite materials where different electron strucures are integrated and contribute to an efficient electronic material. We have published results with collaborators in USA, Sweden, Denmark, Germany, UK, Austria, Australia and India and been invied to conferences.

Facilitate calculation of thermoelectric properties for new materials much more reliable than previously possible.

The research project is a collaboration with partners in Oslo, Trondheim, USA and Austria. The research project is motivated by thermoelectric materials and aims to explore and test new concepts which has the potential for large improvements over present days thermoelectric devices. The present research will be hi risk for the direct short term impact on thermoelectric materials while being medium risk by its large potential for transfer of knowledge and methods to other fields. The project will have strong theoretical and experimental elements. New theoretical approaches are sought, new experimental techniques will be developed, while the project will also use present state of the art theoretical calculation strategies, state of the art synthesis techniques and state of the art analytical material characterization facilities. The project have its origin in BATE, an initiative on Basic and Applied Thermo Electric,s where researchers have collaborated on thermoelectric materials for several years which have resulted in high quality scientific work.