Using nanostructures to improve the performance of bulk thermoelectric materials is a very effective and prevailing method. The integration of several optimization strategies into a single thermoelectric material using multi-nanostructure doping can optimize the properties at multiple levels. In this work, we use the combination of the energy filtering effect and conductive channels to greatly optimize the thermoelectric performance of SnTe. Specifically, we first incorporated Mg_3.2Sb_0.6Bi_1.4 alloy nanoparticles into Sn_1.03Te. As an n-type semiconductor, Mg_3.2Sb_0.6Bi_1.4 can not only effectively neutralize the excessive hole in p-type SnTe, but also generate energy filtering effect due to the P–N junction barrier. Thus, the electronic thermal conductivity and the Seebeck coefficient are optimized. Then, the conductive channel constructed by doping multi-walled carbon nanotubes (MWCNTs) was used to further improve the thermoelectric properties of SnTe. When carriers are transported in the conductive channel, the interference of lattice structure and other factors can be effectively reduced so that the mobility of carriers can be further improved. In addition, we introduce Bi elemental elements to enhance the high frequency phonon scattering based on the existing optimization. As a result of this synergistic effect, an ultralow κ_tot ∼0.96 Wm⁻¹K⁻¹ and a high ZT $\sim$1.56 are obtained at 873 K in SnBi_0.03Te-1% Mg_3.2Sb_0.6Bi_1.4-0.2% MWCNTs.

使用纳米结构来改善整体热电材料的性能是一种非常有效且流行的方法。使用多纳米结构掺杂将几种优化策略集成到单个热电材料中，可以在多个级别上优化性能。在这项工作中，我们结合了能量过滤效果和导电通道，极大地优化了SnTe的热电性能。具体而言，我们首先将Mg _3.2 Sb _0.6 Bi _1.4合金纳米颗粒掺入Sn _1.03 Te中。Mg _3.2 Sb _0.6 Bi _1.4作为n型半导体不仅可以有效地中和p型SnTe中过多的空穴，而且由于P–N结势垒而产生能量过滤效果。因此，电子热导率和塞贝克系数被优化。然后，通过掺杂多壁碳纳米管（MWCNT）构造的导电通道被用来进一步改善SnTe的热电性能。当载流子在导电通道中传输时，可以有效地减少晶格结构和其他因素的干扰，从而可以进一步提高载流子的迁移率。另外，我们在现有优化的基础上，引入Bi元素来增强高频声子散射。由于这种协同作用，超低κ结果_TOT ~0.96了Wm ^-1 ķ^-1和高ZT$〜$在873 K下的SnBi _0.03 Te-1％Mg _3.2 Sb _0.6 Bi _1.4 -0.2％MWCNT中获得1.56 。