High-Temperature Thermoelectric Properties of p-Type Yb-Filled Skutterudite Nanocomposites with FeSb2 Nanoinclusions

Bulk thermoelectric (TE) nanocomposite materials have attracted considerable attention due to their great potential to exhibit higher dimensionless figure of merit . Filled skutterudites of both -type and -type have already demonstrated their excellent high-temperature TE performance, good mechanical properties, and thermal stability. Herein, we extend this work to Yb-filled -type skutterudite nanocomposites with precipitated FeSb2 nanoinclusions. Such a nanocomposite material can be easily synthesized by fine control of starting stoichiometry and the subsequent heat treatment process. By taking advantage of these naturally occurring FeSb2 nanoparticles, we achieve (max) = 0.74 in Yb0.6Fe2Co2Sb12/0.05FeSb(2) at 780 K. We apply the method of four coefficients to calculate the density-of-states effective mass and the carrier scattering parameter. We find that a larger effective mass induced by the presence of nanoparticles is the origin of the enhanced Seebeck coefficient.