Abstract

Carbon-nanotube-embedded bismuth telluride (CNT/Bi_2Te_3) matrix composites were fabricated by a powder metallurgy process. Composite powders, whereby 5 vol.% of functionalized CNTs were homogeneously mixed with Bi_2Te_3 alloying powders, were successfully synthesized by using high-energy ball milling process. The powders were consolidated into bulk CNT/Bi_2Te_3 composites by spark plasma sintering process at 350°C for 10 min. The fabricated composites showed the uniform mixing and homogeneous dispersion of CNTs in the Bi_2Te_3 matrix. Seebeck coefficient of CNT/Bi_2Te_3 composites reveals that the composite has n-type semiconducting characteristics with values ranging -55;µV/K to -95;µV/K with increasing temperature. Furthermore, the significant reduction in thermal conductivity has been clearly observed in the composites. The results showed that CNT addition to thermoelectric materials could be useful method to obtain high thermoelectric performance.

• Keywords: Bismuth telluride;Carbon nanotube;Thermal conductivity;Seebeck coefficient;