Thermoelectric performance enhancement of eco-friendly Cu2Se through incorporating CB4.

We have prepared Cu2Se + x wt% CB4 composites with x = 0, 0.1, 0.3, 0.5, and 0.7 by a hydrothermal method and hot-pressing technique. The structural and compositional analysis indicates that pure phase Cu2Se powders were synthesized and the densified layered bulk samples were obtained. Electrical properties testing showed that the sample with x = 0.5 has the high power factor of 0.886 mW m-1 K-2 due to its high Seebeck coefficient. Meanwhile, the thermal conductivity was suppressed to 0.6 W m-1 K-1 at 773 K. As a result, the final optimized ZT value of 1.46 at 773 K was achieved. These results suggest that CB4 could be an alternative inclusion to improve effectively the thermoelectric performance of Cu2Se.