摘要
SnSe是一种极具应用潜力的热电材料。采用熔融法结合SPS烧结制备了一系列SnSe_(0.95)-x%(摩尔分数)MnCl_(2)样品,研究了MnCl_(2)掺杂对n型多晶SnSe热电性能的影响。结果表明,所有样品均表现出明显的各向异性,沿平行于烧结压力方向具有更优异的热电性能。MnCl_(2)掺杂量的增加引起样品中Sn相含量变化以及析出SnCl_(2)相,进而影响材料的载流子浓度和迁移率,同时提升样品热激发后的电导率和Seebeck系数。此外,MnCl_(2)掺杂引入的点缺陷和SnCl_(2)析出相,显著增强声子散射,降低材料的热导率。但随着MnCl_(2)掺杂量逐渐增大,材料的热导率缓慢增加。结果,SnSe_(0.95)-0.5%(摩尔分数)MnCl_(2)样品在773 K时获得了1.01的最大ZT值,是未掺杂样品的近22倍。
SnSe has been demonstrated a thermoelectric material with great application potential.In this paper,a series of SnSe_(0.95)-x mol%MnCl_(2)samples were prepared by melting method combined with SPS sintering,and the effect of MnCl_(2)doping on the thermoelectric properties of n-type polycrystalline SnSe was studied.The results show that all the samples exhibit obvious anisotropy,and have better thermoelectric properties along the direction parallel to the sintering pressure.The increase of MnCl_(2)doping concentration causes the change of Sn phase content and the precipitation of SnCl_(2)phase in the sample,thus affecting the carrier concentration and mobility,and improving the conductivity and Seebeck coefficient of the samples after thermal excitation.In addition,the point defects and SnCl_(2)precipitation introduced by MnCl_(2)doping significantly enhance the phonon scattering and reduce the thermal conductivity of the materials.However,the thermal conductivity increases slightly with the increase of MnCl_(2)doping amount.As a result,the SnSe_(0.95)-0.5 mol%MnCl_(2)sample obtains a maximum ZT value of 1.01 at 773 K,which is nearly 22 times that of the undoped sample.
作者
刘虹霞
程林
张顺
翟立军
孙志刚
LIU Hongxia;CHENG Lin;ZHANG Shun;ZHAI Lijun;SUN Zhigang(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;Shanxi Province Key Laboratory of Magnetic and Electric Functional Materials and the Applications,Taiyuan 030024,China;State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China)
出处
《功能材料》
CAS
CSCD
北大核心
2023年第9期9158-9165,共8页
Journal of Functional Materials
基金
国家自然科学基金项目(12204342,12174297)
山西省基础研究计划项目(202103021224283,202203021212323)
材料复合新技术国家重点实验室开放基金项目(2022-KF-32)
山西省高等学校科技创新项目(2022L288)
来晋工作优秀博士奖励项目(20222039,20222040)
太原科技大学博士科研启动基金项目(20222002,20222015)。
关键词
热电性能
SnSe
N型
卤化物
掺杂
thermoelectric properties
SnSe
n-type
halide
doping