Enhanced power factor of Ag0.208Sb0.275Te0.517 prepared by HPHT

In this Letter, p-type thermoelectric materials Ag_0.208Sb_0.275Te_0.517 with enhanced power factor were prepared by high pressure and high temperature (HPHT) method. The samples are near single phase AgSbTe₂ with a very small quantity of impurities including Ag₂Te and Te. The concentration of impurities decreases with an increase of synthetic pressure. The synthetic pressure-dependent transport properties including electrical resistivity, Seebeck coefficient and power factor were studied at room temperature. We find the power factor of the sample prepared at the synthetic pressure of 2.1 GPa reaches a maximum value of 14.6 μW cm^-1 K^-2, which is about two times higher than that of the same sample prepared at normal pressure (6.9 μW cm^-1 K^-2).