Electrical transport and high thermoelectric properties of PbTe doped with Bi 2Te 3 prepared by HPHT

Abstract

In this paper, n-type lead telluride (PbTe) compounds doped with Bi 2Te 3 have been successfully prepared by high pressure and high temperature (HPHT) technique. The composition-dependent thermoelectric properties of PbTe doped with Bi 2Te 3 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 Bi 2Te 3 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 Bi 2Te 3 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 Bi 2Te 3 as source of dopants.