Phase Analysis and Thermoelectric Properties of Cu-Rich Tetrahedrite Prepared by Solvothermal Synthesis

Because of the large Seebeck coefficient, low thermal conductivity, and earth-abundant nature of components, tetrahedrites are promising thermoelectric materials. DFT calculations reveal that the additional copper atoms in Cu-rich Cu14Sb4S13 tetrahedrite can effectively engineer the chemical potential towards high thermoelectric performance. Here, the Cu-rich tetrahedrite phase was prepared using a novel approach, which is based on the solvothermal method and piperazine serving both as solvent and reagent. As only pure elements were used for the synthesis, the offered method allows us to avoid the typically observed inorganic salt contaminations in products. Prepared in such a way, Cu14Sb4S13 tetrahedrite materials possess a very high Seebeck coefficient (above 400 mu VK-1) and low thermal conductivity (below 0.3 Wm(-1)K(-1)), yielding to an excellent dimensionless thermoelectric figure of merit ZT approximate to 0.65 at 723 K. The further enhancement of the thermoelectric performance is expected after attuning the carrier concentration to the optimal value for achieving the highest possible power factor in this system.

Automated summary

Tetrahedrites are considered promising thermoelectric materials due to their large Seebeck coefficient and low thermal conductivity. DFT calculations show that introducing additional copper atoms in Cu-rich Cu14Sb4S13 tetrahedrite can effectively achieve high thermoelectric performance. A novel method using solvothermal and piperazine as solvent and reagent is employed to prepare Cu-rich tetrahedrite. The prepared Cu14Sb4S13 tetrahedrites exhibit high Seebeck coefficient and low thermal conductivity, resulting in excellent thermoelectric figure of merit.