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

Abstract

We report the synthesis, characterization and thermoelectric properties of lead-free AgSnmSbSe2Tem (m = 2 and 10) systems. Powder X-ray diffraction patterns and Rietveld refinement results were consistent with phases belonging to the Pm3¯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 AgSnmSbSe2Tem (m = 2 and 10) systems exhibited typical degenerate semiconductor behavior, with a carrier concentration of approximately +1021 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 AgSn2SbSe2Te2 at room temperature. Consequently, the power factor (S2σ) 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.