Grain size and compositional gradient dependence of thermoelectric performance for Cu3−xNixSbSe4 materials

Abstract

The ternary Cu3SbSe4 thermoelectric material with diamond-like structure exhibit good thermoelectric performance in the middle temperature region. In this study, the Cu3−xNixSbSe4 (x = 0–0.03) materials were fabricated by melting-ball milling-hot pressing process. The influences of grain size and compositional gradient on the microstructure and thermoelectric properties of Cu3−xNixSbSe4 were evaluated. It is found that the electrical conductivity of Cu2.97Ni0.03SbSe4 was about 33% higher than that of Cu3SbSe4 sample, and the lattice thermal conductivity was reduced from 3.3 Wm−1K−1 to 2.4 Wm−1K−1 at room temperature due to the grain refinement and more VSe defects. The maximum zT value for the Cu2.97Ni0.03SbSe4 sample was 0.62 at 650 K.

Keywords

• Thermoelectric material
• Grain size
• Compositional gradient
• Cu3−xNixSbSe4