Simultaneous enhancement of thermoelectric and mechanical performance for SnTe by nano SiC compositing

Abstract

Compositing is viewed as a promising strategy to synergistically enhance the thermoelectric and mechanical properties of materials as compared with the element doping method. Herein, different volume percentages of nano SiC (1, 3, 5, and 10 vol%) powders were firstly composited with pristine SnTe. The SiC particles combined well with the SnTe matrix and dispersed homogeneously. The lattice interface effect increases the electrical conductivity up to 700 S m⁻¹ at room temperature due to the increased carrier concentration with addition of 1 vol% SiC. Along with the decreased lattice thermal conductivity (0.67 W m⁻¹ K⁻¹ at 823 K), the maximum figure of merit for SnTe-1 vol% SiC is ∼0.7 which is 1.7 times that of pristine SnTe. And this value is comparable to the results obtained by traditional chemical doping. Additionally, the hardness for all SiC composited samples is also significantly enhanced. Thus nano SiC compositing is a promising way to enhance both the thermoelectric and mechanical properties of SnTe.