Enhanced thermoelectric properties of Cu3SbSe4 via compositing with nano-SnTe

Abstract Cu3SbSe4 is a ternary Cu-based compound with diamond-like structure, which has broad prospects due to its relatively low thermal conductivity and great potential for improving electrical properties. In this study, nano-SnTe was introduced into Cu3SbSe4 matrix by mechanical ball milling and the bulk SnTe/Cu3SbSe4 composites were fabricated using rapidly hot-pressing sintering. The phase composition and microstructure of SnTe/Cu3SbSe4 composites were characterized. The results showed that the added SnTe particles were mainly distributed at the grain boundary of Cu3SbSe4. The addition of nano-SnTe tuned the carrier concentration and improved the electrical conductivity of Cu3SbSe4 greatly. The carrier concentration and electrical conductivity of 4.00%SnTe/Cu3SbSe4 composite at room temperature were 1.68×1020 cm-3 and 3.75×104 Sm-1, respectively. Moreover, the existence of nano-SnTe particles decreased the thermal conductivity of SnTe/Cu3SbSe4 composites obviously. The maximum zT of 0.71 was obtained for the 2.00%SnTe/Cu3SbSe4 sample at 650 K, which was 3.4 times higher than that of pure Cu3SbSe4.