Thermoelectric properties of Sb2Te3–Bi2Te3 solid solutions prepared through melt solidification in liquids

Abstract

Using scanning electron and optical microscopies, we have studied the morphology of fracture surfaces and microstructure of samples of an Sb₂Te₃–Bi₂Te₃ solid solution (p-type conductivity) prepared by hot pressing and extrusion of granules produced through melt solidification in liquids. All of the samples were found to contain an additional phase in the form of a tellurium-based eutectic, and their macroscopic structure was shown to depend on the granule comminution procedure. The electrical conductivity, Seebeck coefficient, and thermal conductivity of the samples have been measured in the range 100–700 K. We have obtained materials with the highest dimensionless thermoelectric figure of merit ZT ~ 1.0 at temperatures from 300 to 440 K.