Synthesis and transport properties of p-type lead-free AgSnmSbSe2Tem thermoelectric systems

Abstract We report the synthesis, characterization and thermoelectric properties of lead-free AgSn m SbSe 2 Te m ( m  = 2 and 10) systems. Powder X-ray diffraction patterns and Rietveld refinement results were consistent with phases belonging to the P m 3 ¯ m space group. The microstructures and morphologies of these systems were investigated using scanning electron microcopy (SEM) and high-resolution transmission electron microscopy (HRTEM). Parallelepiped bars for transport measurements were prepared using two methods: the classical method (CM) from melted samples and the spark plasma sintering (SPS). The AgSn m SbSe 2 Te m ( m  = 2 and 10) systems exhibited typical degenerate semiconductor behavior, with a carrier concentration of approximately +10 21  cm −3 . We determined that the Seebeck coefficient can be substantially increased from approximately +40 μV K −1  (CM) to +70 μV K −1 (SPS) in AgSn 2 SbSe 2 Te 2 at room temperature. Consequently, the power factor ( S 2 σ ) was ∼22 μW cm −1  K −2 . On the basis of the electrical and thermal transport properties, ZT values of ∼0.10 were obtained at room temperature.