Electron and Phonon Transport in n- and p-type Skutterudites

Abstract

ABSTRACTFilled skutterudites are one of the most promising materials for thermoelectric (TE) power generation applications at intermediate temperatures due to their superior TE and thermomechanical performance as compared to other materials. In the past, we have demonstrated that n-type skutterudites can be optimized so that their maximum TE figure of merit reaches 1.7 at 850 K. TE performance of the p-type, however, is lagging behind, which hinders the optimization of skutterudites-based TE module development. In this paper we reveal that the underlying reasons for inferior TE properties of the p-type root in their electronic band structures, which result in higher thermal conductivity at elevated temperatures due to bipolar lattice thermal conduction and lower power factor because of heavy valance bands induced strong electron-phonon interactions. We also identify means of improving the power factor and reducing bipolar effect.