High-Temperature Thermoelectric Properties of p-Type Yb-Filled Skutterudite Nanocomposites with FeSb_(2) Nanoinclusions

摘要

Bulk thermoelectric (TE) nanocomposite materials have attracted considerable attention due to their great potential to exhibit higher dimensionless figure of merit ZT. Filled skutterudites of both n-type and p-type have already demonstrated their excellent high-temperature TE performance, good mechanical properties, and thermal stability. Herein, we extend this work to Yb-filled p-type skutterudite nanocomposites with in situ precipitated FeSb_(2) 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 FeSb_(2) nanoparticles, we achieve ZT_(max) velence 0.74 in Yb_(0.6)Fe_(2)Co_(2)Sb_(12)/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.