Electrical transport and thermoelectric properties of PbTe doped with Sb2Te3 prepared by high-pressure and high-temperature

In this paper, PbTe samples doped with Sb2Te3 have been successfully prepared by the high-pressure and high-temperature (HPHT) technique and the composition-dependent thermoelectric properties of PbTe have been studied at room temperature. Sb2Te3 exhibit the same character as the other dopants used for optimizing the carrier concentration of PbTe while the carrier concentration of PbTe prepared at ambient pressure is not sensitive to the Sb2Te3 content. The lattice thermal conductivity, which is lower than that of prepared by hot-pressing, decreases with increase of Sb2Te3. The figure-of-merit, Z, increases first and then decreases slowly with an increase of Sb2Te3 content and a maximum value of 8.7 × 10−4/K was obtained with 0.05 mol% Sb2Te3 doped. This value is much higher than that PbTe doped with PbI2 prepared at normal pressure with the same carrier concentration. These results indicate that HPHT technique may be helpful to prepare thermoelectric materials with enhanced thermoelectric properties.