Nanostructuring materials using solution synthesis approach for high performance thermoelectric devices

Abstract

Recently a few years thermoelectric research area have focused on nanosize materials to break through the limit of figure of merit above the 3 for boosting commercialization. We also jumped on the field with two chemical approaches. At the first, we induce the gold particles and combine with existing thermoelectric materials. In particularly, Bi0.5Sb1.5Te3 which is already well-known high performance p type thermoelectric materials at room temperature is sintered with spark plasma sintering (SPS) and hot pressing sintering (HPS) at different temperature. Gold doping compound are shown high carrier concentration due to substitution defect. Therefore high Au containing can affect to get large electrical conductivity around 7.8×104S/m SPS Au 2wt% compound and 13.5×104S/m HPS Au 2wt%. We demonstrated anisotropic properties of Bi0.5Sb1.5Te3 and compare between SPS and HPS compounds depending on temperature. Second strategy is bottom up using colloid solution synthesis process for thermoelectric materials. We focus on the argyrodite crystal which is well known ultra low thermal conductivity to check the nano sizing effect. Here, we reported a new facile synthesis way to fabricate the colloidal Ag8SnSe6 nanocrystals and characterization nanocrystals. ⓒ 2016 DGIST