Abstract With multiple band valleys and intrinsic low thermal conductivity, rock-salt SnSe possesses great potential as a promising thermoelectric material. Herein, we prepare cubic SnSe–AgSbTe2 alloy and demonstrate the synergistically optimized electronic and thermal transport properties. For the former, AgSbTe2 alloying can tune the Fermi surface and promote the band flattening, concurrently improving the density of state effective mass and carrier concentration. For the latter, the strong phonon-defect scattering caused by AgSbTe2 alloying contributes to a great reduction of lattice thermal conductivity. Collectively, an obviously enhanced ZTmax of 1.00 at 820 K and ZTave of 0.70 (300–820 K) are achieved in Sn0.5Ag0.25Sb0.25Se0.5Te0.5. Moreover, AgSbTe2 alloying can also improve the mechanical property and the Vickers hardness reaches 1.90 Gpa, which is over four times higher than that of pristine SnSe.

中文翻译：

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用于热电增强的立方 SnSe-AgSbTe2 合金中的能带平坦化和声子缺陷散射

摘要 岩盐SnSe具有多能带谷和固有的低热导率，具有作为一种有前途的热电材料的巨大潜力。在此，我们制备了立方 SnSe-AgSbTe2 合金并展示了协同优化的电子和热传输性能。对于前者，AgSbTe2合金化可以调整费米表面并促进能带平坦化，同时提高状态有效质量密度和载流子浓度。对于后者，由 AgSbTe2 合金化引起的强声子缺陷散射有助于大大降低晶格热导率。总的来说，Sn0.5Ag0.25Sb0.25Se0.5Te0.5 在 820 K 下实现了 1.00 的明显增强的 ZTmax 和 0.70 (300-820 K) 的 ZTave。此外，AgSbTe2合金化还可以提高机械性能，维氏硬度达到1.90 Gpa，