Enhanced Thermoelectric Performance of Cu2SnSe3-Based Composites Incorporated with Nano-Fullerene

In this study, nano-sized fullerene C60 powder was sufficiently mixed with Cu₂SnSe₃ powder by ball milling method, and the C60/Cu₂SnSe₃ composites were prepared by spark plasma sintering technology. The fullerene C60 distributed uniformly in the form of clusters, and the average cluster size was less than 1 μm. With increasing C60 content, the electrical conductivity of C60/Cu₂SnSe₃ composites decreased, while the Seebeck coefficient was enhanced. The thermal conductivity of composites decreased significantly, which resulted from the phonon scattering by the C60 clusters located on the grain boundaries of the Cu₂SnSe₃ matrix. The highest figure of merit ZT of 0.38 was achieved at 700 K for 0.8% C60/Cu₂SnSe₃ composite.