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.