Improvement of the figure-of-merit by formation of crystallographic texture in Bi2Te3-based thermoelectric compounds

Coarse powders of 200 similar to 300 mu m size and fine powders below 45 mu m size were blended with various ratios, and then synthesized by spark plasma sintering method. The use of coarse powders was beneficial to improve the crystallographic orientation and addition of fine powders reduced the voids existing between coarse powders. When 20 wt% of fine powders were blended with coarse powders, the sintered compound exhibited the maximum figure-of-merit.