Phase Content and Thermoelectric Properties of Optimized Thermoelectric Structures Based on the Ag-Pb-Sb-Te System

Results of x-ray studies and measurements of thermoelectric parameters (Seebeck coefficient S, specific electrical conductivity σ, and thermal conductivity χ) of materials based on lead telluride, such as PbTe, PbTe:Sb, PbTe-Sb2Te3, Pb18Ag1Sb1Te20, Pb18Ag2Te20, and PbTe-Ag2Te, are presented. It was found that PbTe:Sb (with 0.3 at.% Sb) as well as Pb18Ag1Sb1Te20 and Pb18Ag2Te20 systems have the highest thermoelectric figure of merit values. In the case of PbTe:Sb, this is due to a significant increase of the electrical conductivity. In the cases of Pb18Ag1Sb1Te20 and Pb18Ag2Te20, it is due to an increase of the Seebeck coefficient and a significant reduction in the thermal conductivity compared with pure PbTe.