Enhanced Thermoelectric Properties of Graphene/Cu3SbSe4 Composites

Incorporating a nanophase into a matrix is an effective approach to improve thermoelectric (TE) properties of bulk TE materials. In this study, graphene nanosheets were introduced into a Cu3SbSe4 matrix and graphene/Cu3SbSe4 composites were prepared by ball milling and rapid hot-press sintering. Microstructure and thermoelectric transport properties of graphene/Cu3SbSe4 composites were analyzed. It was found that the graphene distributed uniformly in the form of layers at the grain boundaries of Cu3SbSe4 matrix. The electrical conductivity of graphene/Cu3SbSe4 composites increased significantly while the Seebeck coefficient decreased with the increasing content of graphene. The thermal conductivity was effectively depressed due to the enhancement of phonon scattering. The maximum thermoelectric dimensionless figure of merit was 0.75 for 2.00% graphene/Cu3SbSe4 composite at 650 K, which was 3.85 times higher than that of pure Cu3SbSe4.