SnTe has been considered as a nontoxic alternative to the PbTe thermoelectric (TE), but its ZT value is severely limited by the high thermal conductivity and low Seebeck coefficient. Here, we demonstrate that the TE properties of p-type SnTe can be significantly improved by strengthening phonon scattering and band convergence based on the component design. Defect engineering by AgCuTe alloying introduces multiscale scattering centers for heat-carrying phonons and results in a rather low lattice thermal conductivity of 0.35 W m⁻¹ K⁻¹ at 833 K. The reduced energy separation of valence band maxima by Cd doping promotes the band convergence and enhances the Seebeck coefficient. Moreover, the diluted I doping optimizes the hole concentration and suppresses the electronic thermal conductivity. Consequently, a peak ZT of 1.75 at 833 K is achieved in the p-type (Sn_0.96Cd_0.04Te_0.99I_0.01)_0.94(AgCuTe)_0.06 sample. This work provides a feasible and efficient way to improve the TE performance of SnTe, and thus accelerates the application of this eco-friendly TE material.

中文翻译：

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增强的声子散射和能带收敛协同实现高性能 SnTe 热电

SnTe 被认为是 PbTe 热电 (TE) 的无毒替代品，但其ZT值受到高导热性和低塞贝克系数的严重限制。在这里，我们证明了通过基于组件设计加强声子散射和能带收敛，可以显着改善 p 型 SnTe 的 TE 特性。通过 AgCuTe 合金化进行的缺陷工程为载热声子引入了多尺度散射中心，并导致相当低的晶格热导率 0.35 W m ⁻¹ K ⁻¹在 833 K。Cd 掺杂降低了价带最大值的能量分离，促进了能带收敛并提高了塞贝克系数。此外，稀释的 I 掺杂优化了空穴浓度并抑制了电子热导率。因此，在p型(Sn _0.96 Cd _0.04 Te _0.99 I _0.01 ) _0.94 (AgCuTe) _0.06样品中在833K处实现了1.75的峰值ZT 。这项工作为提高 SnTe 的 TE 性能提供了一种可行且有效的方法，从而加速了这种生态友好型 TE 材料的应用。