ICT2014 Abstracts

This study reports the semimetal/semiconductor composites with enhanced thermoelectric performance resulted from interface effects between Sb clusters and Bi_0.5Sb_1.5Te₃ matrix. In this work, the Sb clusters dispersed on the surface of Bi_0.5Sb_1.5Te₃ powders by electroless plating and then rapidly compacted by spark plasma sintering at 673 K and 50 MPa. The crystal structure and microstructure of all bulk specimens have been confirmed by XRD and SEM. Moreover, thermoelectric properties were measured at temperature in the range from 300 K to 500 K. The results show that the electrical conductivity enhanced due to the increase in carrier concentration with increasing the amount of Sb clusters. However, the higher carrier concentration resulted in the improvement of electrical conductivity and the reduction of Seebeck coefficient at room temperature. The enhancement in power factor of Bi_0.5Sb_1.5Te₃/Sb samples arose from the increase in carrier effective mass at higher temperature. Finally, the optimal operation temperature of Bi_0.5Sb_1.5Te₃/Sb samples can be shifted by embedding Sb clusters into Bi_0.5Sb_1.5Te₃ matrix.