Abstract：A series of Co4Sb12-x-yTexSey bulks were successful fabricated via microwave heating synthesis combined with spark plasma sintering, and their phase composition, microstructure and thermoelectric transport properties have been investigated. The analysis of XRD patterns show that the diffraction peaks for all samples are matching to CoSb3 standard card. The analysis of SEM microstructure shows that average grain size for different samples are 8~10μm. The electrical transport properties analysis shows that the doped samples are n-type semiconductor, and the conductivity of Te- single doped sample is higher than that of Se- single and Se-, Te- double doped samples while that of Te double-doped sample, as results, Co4Sb11.9Te0.1 obtains the highest power factor of 3001.3 μW/K2*m at 548K. The thermal transport properties analysis shows that the lattice thermal conductivity plays a major role in the total thermal conductivity. The lattice thermal conductivity of Se-, Te- double doped sample is smaller than that of Se- and Te- single doped samples. The lattice thermal conductivity of CoSb11.8Te0.1Se0.1 is 2.7~3.8 Wm-1K-1. Because the comprehensive electrical performance of Te- single doped samples is much higher than the others, as results, Co4Sb11.9Te0.1 obtains the highest ZT of 0.45 at 673K.
2020, Vol. 27 