Densification, microstructure, and thermoelectric properties of AZO/SrTiO3 composites

Abstract

Al-doped ZnO (AZO) has emerged as a potential high-temperature thermoelectric material with an appropriate Seebeck coefficient and high thermal stability, and hence is considered as a promising material for power generation applications. Herein, we report the fabrication of AZO/SrTiO3 composites with improved thermoelectric performance. The densification, microstructure, and thermoelectric properties of the AZO/SrTiO3 composites were investigated. The significant increase in the relative density of AZO from 89.1 to 98.0% after the addition of SrTiO3 indicates that SrTiO3 promoted the densification of the composites. Furthermore, the electrical conductivity of AZO increased after the addition of SrTiO3, which can mainly be attributed to its enhanced relative density. The AZO/SrTiO3 composite with 2.0 wt% SrTiO3 showed the highest power factor at 1000 K because of its highest electrical conductivity. In addition, the composite showed the highest ZT value, which was 1.8 times higher than that of pure AZO.