Ultra-high Seebeck coefficient of nanostructured Sb-substituted PbTe and fabrication of a thermoelectric generator module

Compounds belonging to the series PbSbxTe1−x and Pb1−xSbxTe (x = 0.1, 0.3, 0.5) were prepared in the nanostructured form by employing high-energy ball-milling and subsequent hot-pressing. The amphoteric property of antimony was utilized to substitute lead and tellurium in the compounds having the formula PbSbxTe1−x and Pb1−xSbxTe to make them p and n. All the compositions were evaluated for their figure of merit (ZT) and power factor after ascertaining their Seebeck coefficient, electrical and thermal conductivities. These compositions exhibited very high Seebeck coefficient both in low- and room-temperature regimes. Thermoelectric generator modules were constructed using combinations of n- and p-type PbSbTe and the voltage developed was measured and compared with the calculated values, and they are found to be in good agreement. Different combinations of p- and n-types from the series were tested, and the best among them were identified.