MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , P. R. China.
Key Laboratory of Materials Physics, Institute of Solid State Physics , Chinese Academy of Sciences , Hefei 230031 , P. R. China.
ACS Appl Mater Interfaces. 2019 Dec 4;11(48):45133-45141. doi: 10.1021/acsami.9b17811. Epub 2019 Nov 20.
Here, we report a peak of 1.85 at 873 K for sulfur and Pb codoped polycrystalline SnSe by boosting electrical transport properties while suppressing the lattice thermal conductivity. Compared with single sulfur doped samples, the carrier concentration is improved 1 order of magnitude by Pb incorporation, thereby contributing to improved electrical conductivity and power factor. Moreover, the introduction of sulfur and Pb suppresses the bipolar thermal conductivity by enlarging the band gap. The lattice thermal conductivity significantly decreased as low as 0.13 W m K at 873 K due to the synergic approach involving suppressing bipolar thermal conductivity, large mass fluctuation induced by sulfur incorporation, and nanoprecipitates. We demonstrate that the combination of tailoring band structure, suppressing bipolar thermal conductivity, and introducing large mass fluctuation contributes to the high thermoelectric performance in SnSe. The high performance was achieved through boosting electrical transport properties while maintaining ultralow thermal conductivity. Our findings offer a new strategy for achieving high performance thermoelectric materials.
在这里，我们通过提高载流子输运性能同时抑制晶格热导率，报道了在 873 K 时硫和 Pb 共掺杂多晶 SnSe 的峰值为 1.85。与单硫掺杂样品相比，Pb 的掺入将载流子浓度提高了一个数量级，从而提高了电导率和功率因子。此外，硫和 Pb 的引入通过扩大带隙抑制了双极热导率。由于抑制双极热导率、硫掺入引起的大质量波动以及纳米沉淀的协同作用，晶格热导率在 873 K 时显著降低至 0.13 W m K 以下。我们证明了通过调整能带结构、抑制双极热导率和引入大质量波动来提高 SnSe 的热电性能。通过提高载流子输运性能同时保持超低热导率来实现高性能。我们的研究结果为实现高性能热电材料提供了新的策略。
