Here, we report a remarkable high-average figure of merit (ZT) of 0.73 with the peak ZT of 1.9 in bulk polycrystalline tin selenide (SnSe), generating a high energy conversion efficiency of ∼12.5%. The remarkable high thermoelectric performance results from the enhanced electrical transport properties and reduced lattice thermal conductivity through Schottky vacancies and endotaxial nanostructuring. High angle annular dark field scanning transmission electron microscopy identified amounts of Schottky vacancies and endotaxial PbSe nanoprecipitates present in the SnSe matrix. Schottky vacancies and endotaxial PbSe nanostructures contribute to low lattice thermal conductivity by establishing strong phonon scattering centers. Consequently, an extreme low lattice thermal conductivity of 0.23 W m^–1 K^–1 was achieved at 873 K. Schottky vacancies lead to the increase in carrier concentration, contributing to the enhancement of electrical conductivity and power factor (PF). The maximum PF reached 7.5 μW cm^–1 K^–2 at 873 K. In addition to the high peak ZT, a high average ZT and outstanding thermoelectric conversion efficiency were realized, which ensured its huge potential in practical application. This work provides a new strategy for enhancing thermoelectric performance and designing prospective high-performance thermoelectric materials.

中文翻译：

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通过肖特基空位和内轴纳米结构实现多晶硒化锡中的高热电性能

在此，我们报告了块状多晶硒化亚锡（SnSe）的显着高平均品质因数（ZT）为0.73，峰值ZT为1.9，产生了约12.5％的高能量转换效率。出色的高热电性能归因于通过肖特基空位和内轴纳米结构的增强的电传输性能和降低的晶格热导率。高角度环形暗场扫描透射电子显微镜确定了SnSe基质中存在的肖特基空位和内轴PbSe纳米沉淀的数量。肖特基空位和内轴PbSe纳米结构通过建立强大的声子散射中心来降低晶格热导率。因此，晶格热导率极低，为0.23 W m ^–1 K ^–1肖特基空位导致在873 K时达到最大。空位导致载流子浓度增加，有助于提高电导率和功率因数（PF）。在873 K时，最大PF达到7.5μWcm ^–1 K ^–2。除了高峰值ZT之外，还实现了高平均ZT和出色的热电转换效率，从而确保了其在实际应用中的巨大潜力。这项工作为增强热电性能和设计预期的高性能热电材料提供了新的策略。