Composition-dependent electrical transport properties of Pb50Te52 doped with PbI2 prepared by HPHT

Cubic (Pb50Te52)100−x(PbI2)x (0 ≤ x ≤ 0.065) bulk thermoelectric (TE) materials with enhanced power factor were prepared by high-pressure and high-temperature (HPHT) method. The mean grain size of the samples was about 10 μm. The dependence of electrical transport properties on composition was studied at room temperature. With an increase of x, the Seebeck coefficient in absolute value and the electrical resistivity firstly increase slightly and then decrease dramatically. The maximum power factor reaches 24.2 μW cm−1 K−2 at x = 0.015, which is much higher than that reported previously for the PbTe doped with PbI2 prepared at normal pressure. The results indicate that HPHT combined with trace quantity doping is an effective method to enhance the thermoelectric properties for PbTe.