Effect of Bi Nanoprecipitates on the Thermoelectric Properties of Bi-Sb-Te/Sb2O3 Nanocomposites

Abstract

BiSbTe-based nanocomposites hybridized with ceramic nanoparticles have recently revealed their higher efficiency as thermoelectric materials for near room-temperature applications, as compared to the traditional BiTe-SbTe alloys. Herein, the incorporation of ultra-small Bi nanoprecipitates into the microstructure of a Bi0.5Sb1.5Te3/Sb2O3 nanocomposite and the consequential effects on the thermal and electrical transport properties of this three-phase hybrid system is reported. Electron microscopy characterization and systematic analysis of the thermoelectric properties of Bi0.5Sb1.5Te3/Sb2O3/Bi nanoprecipitate samples suggest that the minute Bi nanoprecipitates increase the charge carrier concentration of the nanocomposites, act as effective scattering sites throughout the microstructure, and shift the maximum Seebeck coefficient values to higher temperatures.