Improvement of Thermoelectric Properties of Bi0.4Sb1.6Te3 with Addition of Nanoscale Zinc Oxide Particles

Bulk Bi0.4Sb1.6Te3 materials with ZnO nanoinclusions have been fabricated by mechanical alloying and plasma-activated sintering. The effects of ZnO addition on the microstructure and thermoelectric performance of the Bi0.4Sb1.6Te3 materials have been studied in detail. Scanning electron microscopy (SEM) observation confirms that the ZnO particles distribute in the Bi0.4Sb1.6Te3 matrix homogeneously until the content is over 0.5 wt.%. The resistivity and Seebeck coefficient of the samples increase slightly with the ZnO content, while the thermal conductivity is reduced effectively by addition of ZnO nanoparticles due to extra phonon scattering at ZnO nanoinclusions, and a maximum ZT of 1.21 is achieved in the sample with 0.3 wt.% ZnO at 373 K.