High-performance bulk Bi0.4Sb1.6Te3.0 thermoelectrics prepared from nanocrystal precursor synthesized via chemical precipitation
High-performance bulk Bi0.4Sb1.6Te3.0 thermoelectrics prepared from nanocrystal precursor synthesized via chemical precipitation
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DOI：
10.1016/j.jssc.2022.123777
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发表时间：
2022-12-22
影响因子：
3.3
通讯作者：
Akamatsu，Kensuke
中科院分区：
文献类型：
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作者：
Fujiwara，Ryosuke;Takashima，Yohei;Akamatsu，Kensuke
Bi0.4Sb1.6Te3.0是一种已知的p型热电材料，在室温附近具有较高的热电性能。在这项研究中，使用单个纳米尺寸的纳米晶体作为前体，通过放电等离子烧结合成块状Bi0.4Sb1.6Te3.0材料，这些材料是通过金属离子的化学沉淀在溶液相中制备的。获得的块体材料由亚微米至微米尺寸的具有各向同性分布的盘状颗粒组成。此外，结构畸变（例如应变和/或缺陷）可以在烧结时直接引入晶粒中，这可能是由于在烧结过程中小纳米晶体前体不完全聚结以形成更大的晶粒。由于使用了无杂质的纳米晶体前体和晶粒内部包含的局部晶格畸变分别充当声子的散射节点，所得块体材料表现出高电导率和相当低的晶格热导率。在 355 K 时，最大无量纲品质因数 (ZT) 达到 1.42，因此，这项工作为制造高性能硫族化物基热电材料提供了有效的方法。
Bi0.4Sb1.6Te3.0is a known p-type thermoelectric material with high thermoelectric performance near room temperature. In this study, bulk Bi0.4Sb1.6Te3.0materials are synthesized via spark plasma sintering using single nanometer-sized nanocrystals as precursors, which are prepared in the solution phase by chemical precipitation from metallic ions. The obtained bulk material consists of submicron-to-micrometer-sized disk-shaped grains with isotropic distribution. Additionally, structural distortion such as strain and/or defects can be directly introduced into grains upon sintering, presumably due to the incomplete coalescence of the small nanocrystal precursors to form larger grains during the sintering process. The resultant bulk material exhibits high electrical conductivity and considerably low lattice thermal conductivity, due to the utilization of impurity-free nanocrystal precursors and local lattice distortions included inside grains acting as scattering nodes of phonons, respectively. The maximum dimensionless figure of merit (ZT) is achieved to be 1.42 at 355 K, and, therefore, this work provides effective methodology to fabricate high-performance chalcogenide-based thermoelectric materials.