Enhancement in thermoelectric performance of n-type Pb-deficit Pb-Sb-Te alloys

Abstract : PbTe based materials are well known for their high performance thermoelectric properties. Here, a systematic study of thermoelectric transport properties of n-type Pb-deficit Pb0.98-xSbxTe alloys with carrier concentrations in the range of 10-19 cm-3 is presented from room temperature to 623 K. A maximum thermoelectric figure of merit (zT) of 0.81 was achieved at 623 K for 4 mol% Sb containing Pb-deficit composition, by the cumulative integration of enhanced power factor and significant reduction in thermal conductivity. The scattering of phonons at Pb vacancies, contributed to the reduction of lattice thermal conductivity, and thereby strikingly boosted the zT of the Pb-deficit samples when compared with the pristine Pb1-xSbxTe.