High-performance eco-friendly MnTe thermoelectrics through introducing SnTe nanocrystals and manipulating band structure
High-performance eco-friendly MnTe thermoelectrics through introducing SnTe nanocrystals and manipulating band structure
复制标题
通过引入 SnTe 纳米晶和操纵能带结构制备高性能环保 MnTe 热电材料
DOI：
10.1016/j.nanoen.2020.105649
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发表时间：
2021-03-01
期刊：
影响因子：
17.6
通讯作者：
Tang, Guodong
中科院分区：
文献类型：
--
作者：
Deng, Houquan;Lou, Xunuo;Tang, Guodong
碲化锰是一种地球资源丰富、环境友好的金属元素，在中温区具有很大的余热回收潜力。然而，其低载流子浓度限制了其热电性能。在这里，我们通过操纵能带结构和引入SnTe纳米晶来实现MnTe的热电性能。我们发现，纳入SnTe发挥了高的能带会聚在MnTe的电子结构，导致显着增强塞贝克系数。与以前报道的掺杂MnTe相比，Seebeck系数大大提高。此外，通过引入SnTe，可以同时优化载流子浓度。大的塞贝克系数与增加的电导率相结合，产生类似于1230 μ Wm（-1）K-2的高功率因数。同时，SnTe纳米晶体有助于实现高效的声子散射，导致晶格热导率显著降低。所提出的新策略使MnTe的电子和声子输运发生了变化，使得Mn1.06Te-2%SnTe材料在873 K时的ZT达到了创纪录的1.4。我们的发现促进了MnTe基材料作为中温余热回收的强有力的候选者。
MnTe, which is comprised of earth-abundant and environmentally friendly elements, shows great potential for waste heat recovery in the moderate temperature range. However, its low carrier concentration limits its thermoelectric performance. Here, we achieved ultrahigh thermoelectric performance of MnTe by manipulating band structure and introducing SnTe nanocrystals. We found that incorporation of SnTe exerts a high band convergence in the electronic structure of MnTe, leading to remarkable enhancement of Seebeck coefficient. The Seebeck coefficient was greatly enhanced compared with previously reported doped MnTe. Furthermore, the carrier concentration can be optimized simultaneously by introducing SnTe. The large Seebeck coefficient combined with increased electrical conductivity give rise to high power factor similar to 1230 mu Wm(-1) K-2. Meanwhile, SnTe nanocrystals help to achieve highly effective phonon scattering leading to markedly reduced lattice thermal conductivity. The proposed novel strategy decouples electron and phonon transport of MnTe, contributing to a record high ZT of similar to 1.4 at 873 K for the Mn1.06Te-2% SnTe material. Our finding promotes MnTe-based materials as a robust candidate for waste heat recovery at medium temperature.