Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 63: Transport (Diffusion, conductivity, heat)

MM 63.5: Vortrag

Donnerstag, 15. März 2018, 16:45–17:00, TC 010

Improvements in thermoelectric material performance — •Genadi Naydenov, Philip Hasnip, Vlado Lazarov, and Matthew Probert — Department of Physics, University of York, York, YO10 5DD, UK

Thermoelectric technology has the potential to convert waste heat into useful electricity, dramatically improving energy efficiency. Optimising thermoelectric materials focuses on increasing their power factor and decreasing their thermal conductivity. Recent experimental and theoretical studies have shown that half-Heusler systems, e.g. NbFeSb, can reach a high power factor (∼10 mWm⁻¹K⁻¹) even at room temperature, and that the thermal transport is dominated by phonons. The phonon thermal conductivity may be lowered by substitution with heavier elements, which introduce point scatterers. Recently the half-Heusler TaFeSb has also been predicted to be an excellent thermoelectric material, but has yet to be investigated thoroughly. We will present the results of our first-principles materials modelling investigation into the thermoelectric properties of pure TaFeSb, NbFeSb and Ta_xNb_1−xFeSb, and show how the power factor and ZT may be optimised by judicious choices of x and doping concentration. We show that p-type Ta_xNb_1−xFeSb is an excellent candidate thermoelectric material.