Effect of Rare-earth Variable-valence Element Eu doping on Thermoelectric Property of BiCuSeO
Effect of Rare-earth Variable-valence Element Eu doping on Thermoelectric Property of BiCuSeO
复制标题
DOI：
10.15541/jim20190570
复制
发表时间：
2020
影响因子：
1.7
通讯作者：
Huijun Kang;Xiaoying Zhang;Yanxia Wang;Jianbo Li;Yang Xiong;Daquan Liu;Zerong Yang;Tongmin Wang
中科院分区：
文献类型：
--
作者：
Huijun Kang;Xiaoying Zhang;Yanxia Wang;Jianbo Li;Yang Xiong;Daquan Liu;Zerong Yang;Tongmin Wang
BiCuSeO作为一种新型的中温热电材料，由于其低的本征热导率和较高的Seebeck系数而备受关注。研究了变价稀土元素Eu取代Bi位对BiCuSeO基材料微观结构和热电性能的影响。结果表明，掺杂BiCuSeO样品中存在Eu 2+和Eu 3+两种价态离子。Eu的掺杂不仅提高了BiCuSeO的载流子浓度，而且改变了BiCuSeO基体的能带结构，从而有效地改善了BiCuSeO的电输运性质。Bi 0.85Eu0.15CuSeO的电导率在82 3 K时达到98 S·cm-1，是未掺杂样品的6倍。Bi 0.975Eu0.0 2 5CuSeO样品在82 3 K时的功率因数为0.32mW·cm-1·K-2，ZT为0.49。研究表明，变价态稀土元素的掺杂可以提高材料的热电性能。
: As a new promising thermoelectrical material in the range of intermediate temperature, BiCuSeO attracts much attention due to the combination of low intrinsic thermal conductivity and relatively high Seebeck coefficient. In this study the effects of substituting variable-valence rare-earth element Eu for Bi site on the microstructure and thermoelectric performance of BiCuSeO-based material were investigated. The results indicate that ions of two valence states, Eu 2+ and Eu 3+ , coexist in the doped BiCuSeO samples. The doping of Eu not only improves the concentration of the carriers, but also modifies the band structure of BiCuSeO matrix, resulting in effective improvement of electrical transport properties. The electrical conductivity of Bi 0.85 Eu 0.15 CuSeO reaches 98 S∙cm -1 at 823 K, which is 6 times as high as that of the undoped sample. The power factor of 0.32 mW∙m -1 ∙K -2 and ZT of 0.49 can be achieved at 823 K for Bi 0.975 Eu 0.025 CuSeO sample. This study shows that the doping of variable-valence rare-earth elements can improve the thermoelectric properties of materials.