低温下双层CrI3热电性能的第一性原理研究  

First Principles Study on Thermoelectric Properties of Double Layer CrI3at Low Temperature

作　　者：周哲 李艳丽 ZHOU Zhe;LI Yan-li(School of Science,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学理学院,武汉430070

出　　处：《武汉理工大学学报》2023年第4期16-21,共6页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(2021-KF-16).

摘　　要：采用了第一性原理的计算方法,通过密度泛函理论(DFT)以及玻尔兹曼输运方程(BTE)研究了双层CrI3的热电性能(TE)。计算了其能带图和态密度图(DOS),以及在10K、30K、50K下的塞贝克系数S、电导率σ、电子热导率Ke、功率因子PF随着载流子浓度n的变化图。计算结果表明双层CrI3的基态是反铁磁性(AFM),在常数弛豫时间近似(CRTA),低温下表现出较高的电导率和塞贝克系数,p型的塞贝克系数大于n型,且不论是塞贝克系数还是电导率均对温度的敏感性很低。高的塞贝克系数以及高的电导率导致了较高的功率因数PF,1.686×10^(-4) Wm^(-1) K^(-2)(n型)和1.098×10^(-4 )Wm^(-1) K^(-2)(p型),说明了双层CrI3具有优异的热电性能,且n型掺杂下的双层CrI3相对于p型掺杂的热电性能更加优异,为磁性热电材料的发展做出了贡献。The thermoelectric properties(TE)of the bilayer CrI3were investigated with the first principles calculations by density functional theory(DFT)and Boltzmann transport equation(BTE).The energy band diagram and density of states diagram(DOS),as well as the seebeck coefficient S,electrical conductivityσ,electronic thermal conductivity Keand power factor PF with the carrier concentration n at 10K,30K,50Kwere calculated.The results show that the ground state of bilayer CrI3is antiferromagnetic(AFM)and exhibits high conductivity and Seebeck coefficient at low temperature under constant relaxation time approximation(CRTA).The Seebeck coefficient of p-type is larger than that of n-type,and the sensitivity of both Seebeck coefficient and conductivity to temperature is very low.The high Seebeck coefficient and the high electrical conductivity results in a high power factor PF:1.686×10^(-4 )Wm^(-1 )K^(-2)(n-type)和1.098×10^(-4) Wm^(-1 )K^(-2)(p-type).It shows that the double-layer CrI3has excellent thermoelectric performance,and the n-type doped double-layer CrI3has better thermoelectric performance than the p-type doped double-layer CrI3.The research contributes to the development of magnetic thermoelectric materials.

关 键 词：第一性原理 热电性能 磁性热电材料 塞贝克系数 二维材料 

分 类 号：O469[理学—凝聚态物理] O47[理学—电子物理学] O48[理学—物理]