Liu Xiaofang, Zhang Bin, Chen Yao, Wu Hong, Wang Hengyang, Yang Meiling, Wang Guoyu, Xu Jingtao, Zhou Xiaoyuan, Han Guang
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
Analytical and Testing Center, Chongqing University, Chongqing 401331, China.
ACS Appl Mater Interfaces. 2020 Oct 7;12(40):44805-44814. doi: 10.1021/acsami.0c13651. Epub 2020 Sep 24.
SnTe is proposed to be an intriguing low-toxicity alternative to PbTe. Herein, we report the diminished lattice thermal conductivity (κ) and enhanced of SnTe by way of vacancy engineering. (SnTe)(SbTe) ( = 0.03, 0.06, and 0.10) and (SnTe)(SbSe) ( = 0.03 and 0.06) were synthesized by blending and sintering their solution-synthesized nano/microstructures (i.e., SnTe octahedral particles, SbTe nanoplates, and SbSe nanorods). Benefiting from the chemical reactions during sintering, single-phase SnTe-based solid solutions were formed when or is not higher than 0.06, into which tunable concentrations of Sn vacancies were introduced. Such vacancies significantly enhance phonon scattering, leading to the sharply reduced room temperature κ of 1.40 and 1.26 W m K for = 0.06 and = 0.06 samples, respectively, as compared to 3.73 W m K for pristine SnTe. Enabled by point defects with the highest concentration and SnSbTe secondary phase, (SnTe)(SbTe) sample obtains the lowest κ of 0.70 W m K at 813 K. Ultimately, maximum values of 0.6 and 0.7 at 813 K are achieved in (SnTe)(SbTe) and (SnTe)(SbSe), respectively. This study demonstrates the effectiveness of vacancy engineering in improving of SnTe-based materials.
人们认为碲化锡（SnTe）是一种极具吸引力的低毒性碲化铅（PbTe）替代物。在此，我们报告通过空位工程降低了SnTe的晶格热导率（κ）并提高了其热电性能。通过混合和烧结溶液合成的纳米/微结构（即SnTe八面体颗粒、SbTe纳米片和SbSe纳米棒），合成了（SnTe）（SbTe）（x = 0.03、0.06和0.10）和（SnTe）（SbSe）（x = 0.03和0.06）。受益于烧结过程中的化学反应，当x不高于0.06时形成了单相SnTe基固溶体，其中引入了可调浓度的Sn空位。这些空位显著增强了声子散射，导致室温下κ急剧降低，x = 0.06和x = 0.06的样品的κ分别为1.40和1.26 W m⁻¹ K⁻¹，而原始SnTe的κ为3.73 W m⁻¹ K⁻¹。由于具有最高浓度的点缺陷和SnSbTe第二相，（SnTe）（SbTe）样品在813 K时获得了最低的κ值0.70 W m⁻¹ K⁻¹。最终，（SnTe）（SbTe）和（SnTe）（SbSe）在813 K时分别实现了0.6和0.7的最大热电优值（ZT）。这项研究证明了空位工程在提高SnTe基材料热电性能方面的有效性。
