ICT2014 Abstracts

N-type filled skutterudites are regarded as potential candidates for thermoelectric power generation because of their high performance. Alkali metals, alkaline earth metals and rare earth elements are usually selected as fillers to reduce their thermal conductivities. Here we report that substitution of Co with Fe not only reduces the lattice thermal conductivity, but also is able to adjust the carrier concentration to the optimum value so that higher ZT value can be obtained. In this way, we can fill much more atoms in cage of Fe_yCo_4-ySb₁₂ than Co₄Sb₁₂ based-skutterudite by adjusting the Fe/Co ratio to further reduce the thermal conductivity and obtain the ZT value of around 1.0 at 500℃ among (Yb, Ca, Al, Ga, In)_0.2-0.8Fe_yCo_4-ySb₁₂.