Enhanced thermoelectric properties and thermal stability of Cu1.8S-rGO nanocomposite by low energy carrier filtering effect

Abstract

Cu1.8S has received a lot of interest as a prospective thermoelectric material with the best performance and abundant resources. While high charge carrier concentration contributes to the high electrical conductivity and power factor values, grain-boundary engineering is required to improve the phonon scattering and thermal stability of Cu1.8S. We used a simple process that combined nanoparticles via mechanical alloying and post-annealing to introduce the reduced graphene oxide (rGO) heterointerface into the Cu1.8S matrix. A significant enhancement of power factor has been realized that the highest power factor is 721 μWm−1 K−2 at 550 K in the composite Cu1.8S/rGO with 10 % rGO, which is higher than the pure Cu1.8S. Furthermore, following four cycles of testing from ambient temperature to 550 K, the composite demonstrated excellent repeatability of power factor, confirming its practical application potential.