Thermoelectric Properties of Te-Doped Ba_0.32Co₄Sb_12−xTe_xPrepared at HPHT

Polycrystalline skutterudites Ba_0.32Co₄Sb_12−xTe_x (nominally x=0.1–0.7) are synthesized by the high pressure and high temperature (HPHT) method. The influence of Te substitution on electrical transport properties are investigated in the temperature range of 300–710 K. All the samples show n−type conduction. It is found that the presence of Te substantially decreases electrical resistivity without any detrimental effect on the Seebeck coefficients, which improves the power factor. Among all the samples, Ba_0.32Co₄Sb_11.5Te_0.5 shows the highest thermoelectric figure of merit of 0.76 at 710 K.