Preparation and Thermoelectric Properties of ZnTe-doped Bi0.5Sb1.5Te3 Single Crystal

Abstract In this work, Bi0.5Sb1.5Te3 single crystal doped with 6 mol% ZnTe was fabricated using a vertical Bridgman method. A region about 20× 70 mm2 in dimensions along (001) cleavage plane is obtained. The as-grown crystal exhibits remarkable anisotropy of TE properties that parallel and perpendicular to (001) in 300- 480 K temperature range. It is found the highest power factor PF∥(001)= ∼50 μWcm-1K-2 and PF⊥(001)= ∼18 μWcm-1K-2 are obtained, and the total thermal conductivities for both directions are κ∥(001)=1.8 Wm-1K-1 and κ⊥(001)= 0.8 Wm-1K-1. Thus, the peak figure of merit ZT∥(001)= 1.05 and ZT⊥(001)= 0.9 are realized, which might expand its application scope compared with the commercial Bi2Te3-based TE materials.