Enhanced thermoelectric performance in p-type Mg_3Sb_2 via lithium doping
Enhanced thermoelectric performance in p-type Mg_3Sb_2 via lithium doping
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通过锂掺杂增强 p 型 Mg_3Sb_2 的热电性能
DOI：
10.1088/1674-1056/27/4/047212
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发表时间：
2018
影响因子：
1.7
通讯作者：
Zhao Huaizhou
中科院分区：
文献类型：
--
作者：
Wang Hao;Chen Jin;Lu Tianqi;Zhu Kunjie;Li Shan;Liu Jun;Zhao Huaizhou
Zintl化合物Mg_3Sb_2由于其高热电性能以及成本效益、无毒和环境友好的特性，最近被认为是有前途的热电材料。然而，本质上 p 型 Mg_3Sb_2 由于其导电性差而表现出较低的品质因数（723 K 时 zT = 0.23）。本研究采用高能球磨和放电等离子烧结(SPS)工艺制备了一系列Mg_(3-x)Li_xSb_2块体材料。对这些材料的电传输测量表明，相对于未掺杂的样品，功率因数显着改善，这主要归因于载流子浓度的增加，导致在最佳掺杂水平 x = 0.01 时，723 K 时的最大 zT 为 0.59。此外，计算出工程zT和能量转换效率分别为0.235和4.89%。据我们所知，这些是所有报道的单元素掺杂 p 型 Mg_3Sb_2 基化合物中的最高值。
The Zintl compound Mg_3Sb_2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective, nontoxicity and environment friendly characteristics. However, the intrinsically p-type Mg_3Sb_2 shows low figure of merit (zT = 0.23 at 723 K) for its poor electrical conductivity. In this study, a series of Mg_(3-x)Li_xSb_2 bulk materials have been prepared by high-energy ball milling and spark plasma sintering (SPS) process. Electrical transport measurements on these materials revealed significant improvement on the power factor with respect to the undoped sample, which can be essentially attributed to the increased carrier concentration, leading to a maximum zT of 0.59 at 723 K with the optimum doping level x = 0.01. Additionally, the engineering zT and energy conversion efficiency are calculated to be 0.235 and 4.89%, respectively. To our best knowledge, those are the highest values of all reported p-type Mg_3Sb_2-based compounds with single element doping.