過剰のTeがHP法で作製したp型Bi0.40Sb1.60Te3.00+x(0.00≤x≤0.40)材料の微構造と熱電特性に与える影響

The purpose of this study is to investigate the effect of excess Te on the microstructure and thermoelectric properties of p-type Bi 0.40 Sb 1.60 Te 3.00+x (0.00≤x≤0.40) materials prepared by a hot pressing method. For such materials, the grain size and (001) orientation increased, the resistivity and Seebeck coefficient decreased, and the thermal conductivity gradually increased with increasing amount of excess Te. Based on our analysis, it is reasonable to consider that excess Te was empoloyed as a dopant, which increased carrier density. The figure of merit of p-type Bi 0.40 Sb 1.60 Te 3.00+x materials gradually degreased with increasing amount of excess Te, and showed a maximum of Z=3.57×10 -3 K -1 at a composition ratio of x=0.00.