Influence of Spark Plasma Sintering Temperature on Microstructure and Thermoelectric Properties of Cu-Doped Bi0.5Sb1.495Te3 Compound

Abstract

Due to air pollution, global warming and energy shortage demands new clean energy conversion technologies. The conversion of industrial waste heat into useful electricity using thermoelectric (TE) technology is a promising method in recent decades. Still, its applications are limited by the low efficiency of TE materials in the operating range between 400-600 K. In this work, we have fabricated Cu0.005Bi0.5Sb1.495Te3 powder using a single step gas atomization process followed by spark plasma sintering at different temperatures (623, 673, 723, and 773 K), and their thermoelectric properties were investigated. The variation of sintering temperature showed a significant impact on the grain size. The Seebeck coefficient values at room temperature increased significantly from 127 μVK to 151 μV/K with increasing sintering temperature from 623 K to 723 K due to decreased carrier concentration. The maximum ZT values for the four samples were similar in the range between 1.15 to 1.18 at 450 K, which suggest these materials could be used for power generation in the mid-temperature range (400-600 K).

Keywords

• bismuth antimony telluride
• gas atomization
• spark plasma sintering
• microstructure
• thermoelectric materials