High thermoelectric performance of Bi2-xSbxTe3 bulk alloys prepared from non-nanostructured starting powders

Abstract

In this work, hot press and hot deformation were applied to p-type Bi2-xSbxTe3 (x = 1.5-1.8) starting powders that have not undergone nanostructuring processing. The effects of hot pressing and hot deformation, as well as Sb-alloying, on the microstructure and the thermoelectric properties of the Bi2-xSbxTe3 alloys were systematically investigated. The results of this study are compared to those of others, which have addressed similar issues in samples prepared with analogous compaction techniques. ZT value of 1.12 at 375 K for hot pressed Bi0.4Sb1.6Te3 and ZT value of 1.24 at 375 K for hot deformed Bi0.4Sb1.6Te3 were achieved. To our knowledge, the latter ZT value is only slightly lower than the highest ever reported (ZT 1.3) for p-type bismuth telluride-based alloys prepared using starting materials without nanostructuring, suggesting that simpler preparation techniques can be applicable in modules fabrication.