The Effect of Powder Size on Thermoelectric Properties of 95%Bi₂Te₃-5%Bi₂Se₃ Alloy

Abstract

The n-type (95%Bi2Te3- 5%Bi2Se3) compound was newly fabricated by gas atomization and hot extrusion, which is considered to be a mass production technique of this alloy. The effect of powder size on thermoelectric properties of 0.04% SbI3 doped 95%Bi2Te3- 5%Bi2Se3 alloy were investigated. Seebeck coefficient (α) and Electrical resistivity (ρ) increased with increasing powder size due to the decrease in carrier concentration by oxygen content. With increasing powder size, the compressive strength of 95%Bi2Te3-5%Bi2Se3 alloy was increased due to the relative high density. The compound with ~300 μm size shows the highest power factor among the four different powder sizes. The rapidly solidified and hot extruded compound using 200~300 μm powder size shows the highest compressive strength.