Electrical transport and thermoelectric properties of PbTe doped with Sb 2Te 3 prepared by high-pressure and high-temperature

Abstract

In this paper, PbTe samples doped with Sb 2Te 3 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. Sb 2Te 3 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 Sb 2Te 3 content. The lattice thermal conductivity, which is lower than that of prepared by hot-pressing, decreases with increase of Sb 2Te 3. The figure-of-merit, Z, increases first and then decreases slowly with an increase of Sb 2Te 3 content and a maximum value of 8.7 × 10 −4/K was obtained with 0.05 mol% Sb 2Te 3 doped. This value is much higher than that PbTe doped with PbI 2 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.