Synergistically improving thermoelectric and mechanical properties of Ge0.94Bi0.06Te through dispersing nano-SiC

Abstract

In this paper, Ge0.94Bi0.06Te was firstly fabricated by mechanical alloying. Compared with the Ge0.94Bi0.06Te sample prepared by the melting process, the maximum ZT achieved an improvement from 1.4 to 1.8. The thermoelectric performance of Ge0.94Bi0.06Te can be improved through suppressing Ge vacancies and refining grains via mechanical alloying. Further introducing nano-SiC into the matrix of Ge0.94Bi0.06Te improves thermoelectric performance by increasing Seebeck coefficient and reducing thermal conductivity. Meanwhile, the mechanical properties including the microhardness and Young's modulus are also enhanced by dispersing nano-SiC. Consequently, a maximum ZT ~ 2.1 at 723 K was achieved in GeTe-based materials.