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

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.