Advanced thermoelectric for waste heat harvesting

Abstract

High entropy engineering has been observed to be able to extend the limits of optimization in thermoelectric performance. This technique involves introducing different atomic species to manipulate the configurational entropy of a material, resulting in the formation of a high entropy alloy. In this study, pellets of AgSnSbSe1.5PbxTex+1.5 were synthesized at varying PbTe concentration to analyse the effects of the dopant concentration on the thermoelectric properties. Pellets were thermal annealed and sintered with spark plasma sintering (SPS) before the thermoelectric properties were measured using the ULVAC ZEM-3 machine and the laser flash analysis (LFA) method. The structure and morphology of the pellets were characterized with the Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). After measurements, the composition of AgSnSbSe1.5Te1.5 + 10 % PbTe had the most favourable modifications in terms of its electrical and thermal conductivity. From the temperature range of 423 – 773 K, it displayed a high average power factor and ZTave of ~8.6 µW·cm-1·K-2 and ~0.69 accordingly. A peak ZT of ~0.80 was measured at the temperature of 723 K.