Thermoelectric properties of n-type 95%Bi2Te3–5%Bi2Se3 compounds fabricated by gas-atomization and spark plasma sintering

Highlights: • Gas Atomization process was used to fabricate 95%Bi2Te3–5%Bi2Se3 powders. • Characterization of gas atomized powders were conducted. • SPS process was used to sinter the atomized powders at different sintering temp. • Thermoelectric properties, density and hardness of SPS-ed bulks were analyzed. -- Abstract: In this study, n-type 95%Bi2Te3–5%Bi2Se3 doped with 0.04% SbI3 thermoelectric materials was fabricated by gas-atomization and spark plasma sintering (SPS) at a temperature range of 623–723 K. The microstructure of the gas atomized powder shows spherical shape, fine particle size and homogeneously distributed grains. The density of the sintered bulk reached nearly 100% of the theoretical density, where micro Vickers Hardness was found around 54–57 Hv. The Seebeck coefficient (α) of the sintered bulk decreased while electrical resistivity and thermal conductivity (κ) increased with increasing sintering temperature to 723 K, resulting in a decrease in figure of merit. The maximum figure of merit (ZT) was 0.76, which was obtained in the sintered bulk at 623 K