Reevaluation of PbTe_(1−x)I_x as high performance n-type thermoelectric material

Abstract

Thermoelectric transport properties of n-type PbTe_(1−x)I_x with carrier concentrations ranging from 5.8 × 10^(18)–1.4 × 10^(20) cm^(−3) are reinvestigated from room temperature to 800 K. The electronic transport properties, resistivity and Seebeck coefficient in this study are effectively consistent with prior reports, however the thermal conductivity has been found to be historically overestimated. The reassessment of the thermal transport properties, in combination with careful control of the carrier density by iodine doping, reveals a significantly larger figure of merit, zT ~ 1.4, than often previously reported for n-type PbTe. The results and analysis of the data from this study lead to a redetermination of zT for this historical thermoelectric material and provide a renewed interest in n-type PbTe based materials.