Electron and phonon transport in Co-doped FeV0.6Nb0.4Sb half-Heusler thermoelectric materials
Electron and phonon transport in Co-doped FeV0.6Nb0.4Sb half-Heusler thermoelectric materials
复制标题
共掺杂 FeV0.6Nb0.4Sb halfHeusler 热电材料中的电子和声子输运
DOI：
10.1063/1.4823859
复制
发表时间：
2013-10-07
影响因子：
3.2
通讯作者：
Zhu, Tiejun
中科院分区：
文献类型：
--
作者：
Fu, Chenguang;Liu, Yintu;Zhu, Tiejun
分析了n型Fe1-xCoxV0.6Nb0.4Sb半Heusler热电化合物的电子和声子输运特性。声学声子散射在载流子输运中占主导地位。在单抛物带假设下，得到了E-def-14.1eV的形变势和近似为2.0m(E)的态有效质量密度m*。计算出其带隙约为0.3 eV。根据低温和高温测量，估算了电子和声子的平均自由程。在室温以上，电子的平均自由程大于声子的平均自由程，这与电子迁移率比晶格热导率的降低幅度更大的实验结果相一致。当x=0.015时，在650K获得了最大ZT值，与FeVSb相比提高了近60%。在600K时，最佳掺杂水平为3.0×10(20)cm(-3)。(C)2013 AIP出版有限责任公司。
The electron and phonon transport characteristics of n-type Fe1-xCoxV0.6Nb0.4Sb half-Heusler thermoelectric compounds is analyzed. The acoustic phonon scattering is dominant in the carrier transport. The deformation potential of E-def - 14.1 eV and the density of state effective mass m* approximate to 2.0 m(e) are derived under a single parabolic band assumption. The band gap is calculated to be similar to 0.3 eV. Electron and phonon mean free paths are estimated based on the low and high temperature measurements. The electron mean free path is higher than the phonon one above room temperature, which is consistent with the experimental result that the electron mobility decreases more than the lattice thermal conductivity by grain refinement to enhance boundary scattering. A maximum ZT value of similar to 0.33 is obtained at 650 K for x = 0.015, an increase by similar to 60% compared with FeVSb. The optimal doping level is found to be similar to 3.0 x 10(20) cm(-3) at 600 K. (C) 2013 AIP Publishing LLC.