Electrical transport and high thermoelectric properties of PbTe doped with Bi2Te3 prepared by HPHT

In this paper, n-type lead telluride (PbTe) compounds doped with Bi2Te3 have been successfully prepared by high pressure and high temperature (HPHT) technique. The composition-dependent thermoelectric properties of PbTe doped with Bi2Te3 have been studied at room temperature. The figure-of-merit, Z, for PbTe is very sentivite to the dopants, which could be improved largely although the doped content of Bi2Te3 is very small (<0.08 mol%). In addition, the maximum value reaches to 9.3×10−4 K−1, which is about 20% higher than that of PbTe alloyed with Bi2Te3 sintered at ambient pressure (7.6×10−4 K−1) and several times higher than that of small grain size PbTe containing other dopants. The improved thermoelectric performance in this study may be due to the effect of high pressure and the low lattice thermal conductivity resulting from Bi2Te3 as source of dopants.