산화물 환원법으로 제조된 Bi2SexTe3-x 분말의 열전특성

Abstract

In this research, we studied the thermoelectric properties of selenium(Se) substituted bismuth telluride(Bi2SexTe3-x) composites synthesized by an oxide reduction process. Variation of the Se composition were demonstrated by X-ray diffraction and Vegard's law. The synthesized powder was sintered by the spark plasma sintering. The thermoelectric properties of the sintered body were evaluated by measuring its Seebeck coefficient, electrical resistivity and thermal conductivity. The sintered body of the synthesized powder exhibited n-type thermoelectric characteristics. The substitution of tellurium by selenium has significant impacts on the electrical and thermal transport properties of the Bi2SexTe3-x composites. The Seebeck coefficient and electrical resistivity of the Bi2SexTe3-x sintered body were increased with increasing Se substitution concentration. While thermal conductivity of the Bi2SexTe3-x sintered body were decreased with increasing Se substitution concentration. The sintered body of the Bi2Se0.6Te2.4 powder showed about 1.1 of the figure of merit(ZT) at 50℃.