Bo Lin,Wang Lei,Hou Yangbo,Li Fujin,Liu Sida,Zhang Ruipeng,Zuo Min,Zhao Degang
Ternary Cu 3 SbSe 4 thermoelectric material with a diamond-like structure exhibits good thermoelectric performance in the middle-temperature region. In this study, Cu 2.98 Co 0.02 SbSe 4 material with intrinsically low thermal conductivity was prepared by a melting–ball milling–hot pressing process. The maximum zT value for the Cu 2.98 Co 0.02 SbSe 4 sample was 0.7 at 650 K, which was about 190% higher than that of the pristine sample. The improvement in thermoelectric performance was ascribed to the realization of multi-scale features induced by ball milling. It was found that multiple scattering centers of phonons were formed via interfacial engineering, including dislocations, nano-holes and grain boundaries, which offers an applicable pathway for the reduction of lattice thermal conductivity. Graphical
Ziming Zhang,Zhiqiang Gao,Tingting Deng,Qingfeng Song,Lidong Chen,Shengqiang Bai
Mg3(Sb,Bi)2-based Zintl compounds have attracted lots of attention due to their high thermoelectric performance and good mechanical properties. However, thermally activated mobility, which is ascribed to the grain boundary scattering, greatly limits their practical use. In this work, we reveal the plasticity of Mg3(Sb,Bi)2-based compounds in the compressive strength test. The ab initio analysis indicates that this plasticity should be ascribed to the low slip barrier energy (∼580 mJ m−2), which is only one third of the cleavage energy (∼1600 mJ m−2). Based on this finding, we propose a cold-deformation procedure to elongate particles and to enhance texture, which successfully suppresses the grain boundary scattering. As a result, a high carrier mobility of 86.6 cm2 V−1 s−1 and a high power factor of 16.2 μW cm−1 K−2 in Mg3.1Bi1.5Sb0.49Te0.01 are obtained at room temperature. The plastic deformation capacity of Mg3(Sb,Bi)2 compounds provides a near-net-forming method to fabricate special-shaped devices at room-temperature, which will extend the application fields of thermoelectric techniques.