Recently, a research group led by Prof Qin Xiaoying from the Institute of Solid State Physics, Hefei Institutes of Physical Science has made new progress in the thermoelectric performance of Cu₃SbSe₄. The result obtained from the study proved excellent thermoelectric properties in copper-antimony alloys which were achieved via synergistic regulation of power factors and thermal conductivity.

Thermoelectric materials enables direct conversion between heat and electricity. Therefore, it has been considered as a kind of potentially sustainable energy as it can be used for solid-state refrigerators or heat pumps, replacing moving parts or liquids which are widely used now and harmful to the environment.

In this study, AgSb_0.98Sn_0.02Se₂, a kind of nano particles, were introduced into Cu₃Sb_0.96Sn_0.04Se₄ matrix, and thus new nanocomposites Cu₃Sb_0.96Sn_0.04Se₄ /x wt% AgSb_0.98Sn_0.02Se₂ (x = 0,1,3,5,7) were formed by grinding and electrospark plasma sintering.

The ZT value of Cu₃Sb_0.96Sn_0.04Se₄/5wt% AgSb_0.98Sn_0.02Se₂ sample reached a record of 1.17 due to the reduction of thermal conductivity and the enhancement of carrier mobility, which showed good thermoelectric performance.

Tetrahedrite Cu₃SbSe₄ has attracted much attention due to its cheap components, low intrinsic lattice thermal conductivity and excellent electrical transport properties. However, there is no effective method to increase the power factor and decrease the thermal conductivity simultaneously. The experiment provides a new strategy for improving performance of thermoelectric materials.

This work was supported by the funding support from the Natural Science Foundation of China.

(a) Powder XRD patterns of Cu₃Sb_0.94Sn_0.96Se_4-yS_y (y = 0.5, 1, and 1.5). (b) Lattice parameter a and c with the sulfur content. (Image by CHEN Tao)