Effects of Bi sub(2)Se sub(3) Amount in Thermoelectric Performance of Bi sub(2)(TeSe) sub(3) Materials Fabricated by High-Energy Ball Milling

Amount of Bi sub(2)Se sub(3) has significant role in controlling thermoelectric properties of n-type Bi sub(2)(TeSe) sub(3) material. In this study, effects of Se alloying amount in Bi sub(2)(TeSe) sub(3) thermoelectric materials fabricated by high-energy ball milling and spark plasma sintering were studied and compared with other fabrication methods. Amount of Bi sub(2)Se sub(3) (5%, 10%, 15%, and 20%) did not have any significant effect over fabricated powder size, grains of consolidated bulks, and mechanical properties; however, electrical properties and thermoelectric efficiency were noticeably influenced. Both carrier concentration and carrier mobility decreased with increase in Se amount. In total, 20% Se alloying was effective in improving thermoelectric figure of merit ZT value by almost 40% compared with only 5% Se alloying.