变价稀土元素Eu掺杂BiCuSeO热电性能的研究  

Effect of Rare-earth Variable-valence Element Eu doping on Thermoelectric Property of BiCuSeO

作　　者：康慧君 张校影 王燕遐 李建波 杨雄 刘达权 杨泽荣 王同敏[1] KANG Huijun;ZHANG Xiaoying;WANG Yanxia;LI Jianbo;YANG Xiong;LIU Daquan;YANG Zerong;WANG Tongmin(Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province),School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;Key Laboratory of Material Modification by Laser,Ion and Electron Beams,Ministry of Education,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学材料科学与工程学院辽宁省凝固控制与数字化制备技术重点实验室,大连116024 [2]大连理工大学三束材料改性重点实验室,大连116024

出　　处：《无机材料学报》2020年第9期1041-1046,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金面上项目(51971052,51774065);国家自然科学基金杰出青年基金项目(51525401);辽宁省“兴辽英才计划”(XLYC1808005);大连市高层次人才创新支持计划(2017RQ026)。

摘　　要：作为一种适于中温下使用的极具发展前景的新型热电材料,BiCuSeO由于本征热导率低且Seebeck系数较高而广受关注。本研究探索了变价稀土元素Eu替换Bi位对BiCuSeO热电材料微观组织和热电性能的影响。实验结果显示,样品中同时存在Eu^2+和Eu^3+两种价态的离子,掺杂Eu元素不仅可以增加样品的载流子浓度,还可以调整样品的能带结构,进而改善样品的电输运性能,Bi0.85Eu0.15CuSeO电导率显著提升,在823 K时达到了98 S·cm^–1,相比于未掺杂样品提升了将近6倍。在温度为823 K时,Bi0.975Eu0.025CuSeO的功率因子可达0.32 mW·m^–1·K^–2,ZT值为0.49。本研究表明,掺杂变价稀土元素可以有效改善BiCuSeO热电材料的性能。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 Bi0.85Eu0.15CuSeO 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 Bi0.975Eu0.025CuSeO sample.This study shows that the doping of variable-valence rare-earth elements can effectively improve the thermoelectric properties of BiCuSeO.

关 键 词：热电材料 BiCuSeO 变价元素掺杂 

分 类 号：O472[理学—半导体物理]