[SIS11] Energy Materials

[16D-SIS11-07] Fabrication of Bi₂Te₃-Based Bulk Thermoelectric Materials by a Powder Extrusion Technique

*Z. Wang¹, Z. Chen² (1.University of Science and Technology Beijing, China, 2.Tottori University, Japan)

Keywords:Bi2Te3, thermoelectric materials, powder extrusion

Bi₂Te₃-based thermoelectric materials have remained the cornerstone of commercial thermoelectric solid-state cooling and power generation near room temperature for decades. From the viewpoints of grain refinement and preferred orientation, a powder extrusion technique was proposed to fabricate Bi₂Te₃-based bulk materials. The p-type Bi_0.4Sb_1.6Te₃ extruded samples achieved a maximum value of ZT=1.2, while the n-type Bi₂Te_2.85Se_0.15 extruded samples showed a maximum value of ZT=0.47. Microstructures of the p-type and n-type extruded samples were comparably studied to demonstrate their performance bias, revealing a twining-boundary scattering mechanism. On the basis of the study, doping was employed to improve the performance of n-type extruded samples significantly.