SnTe has attracted worldwide attention as a non-toxic candidate material for thermoelectric applications; however, un-modified SnTe possesses inferior thermoelectric properties. Herein, we report the significantly improved thermoelectric performance in Sb, Mn-codoped SnTe synthesized by energy-efficient melt spinning. Sb segregation was observed at the grain boundaries of Sb-doped and Sb, Mn-codoped SnTe melt-spun ribbons, leading to grain refinement; subsequent sintering promotes the diffusion of Sb while retains Sb-rich particles. Initially, intensified phonon scattering from unique multiscale microstructures, including point defects, Sb-rich particles and high-density dislocations generated after Sb doping, effectively diminishes the lattice thermal conductivity of SnTe, leading to a substantially low value of 0.55 W m⁻¹ K⁻¹ in Sn_0.84Sb_0.16Te at 300 K. Further, the power factors are significantly enhanced via Mn doping owing to valence band convergence, verified by first-principles calculation. Consequently, a peak zT of ~ 1.27 at 773 K and an exceptional average zT of ~ 0.89 over 300–873 K are obtained in Sn_0.72Sb_0.16Mn_0.12Te, which are ~ 110% and ~ 340% higher than those of SnTe, respectively. This study provides an effective pathway to synergistically improve the thermoelectric performance of SnTe by microstructure and band structure engineering, and establishes melt spinning as a controllable synthetic method to high-performance thermoelectrics.

SnTe作为一种无毒的热电应用候选材料已经引起了全世界的关注。然而，未改性的SnTe的热电性能较差。在本文中，我们报告了通过节能熔融纺丝合成的Sb，Mn共掺杂的SnTe的热电性能得到了显着改善。在掺Sb和掺Sb，Mn的SnTe熔纺带材的晶界观察到Sb偏析，导致晶粒细化。随后的烧结促进了Sb的扩散，同时保留了富含Sb的颗粒。最初，来自独特多尺度微结构的声子散射增强，包括点缺陷，富Sb颗粒和Sb掺杂后产生的高密度位错，有效地降低了SnTe的晶格热导率，从而导致0.55 W m的极低值在300 K下，Sn _0.84 Sb _0.16 Te中的^-1 K ^-1。此外，由于价带收敛，通过Mn掺杂可显着提高功率因数，这一点已通过第一性原理计算得到验证。因此，在Sn _0.72 Sb _0.16 Mn _0.12中，在773 K处的峰值zT为1.27，在300–873 K范围内的异常平均zT为0.89。Te，分别比SnTe高约110％和340％。该研究为通过微结构和能带结构工程协同改善SnTe的热电性能提供了一条有效途径，并建立了熔融纺丝作为高性能热电的可控合成方法。