Hu Yang, Jin Yurong, Zhang Guangbiao, Yan Yuli
Institute for Computational Materials Science, School of Physics and Electronics, Henan University Kaifeng 475004 China
Chongqing Institute of Engineering Chongqing 402360 China.
RSC Adv. 2020 Aug 3;10(48):28501-28508. doi: 10.1039/d0ra04984k.
We investigate the transport properties of bulk CaYZ (Y = Au, Hg; Z = As, Sb, Bi, Sn and Pb) by a combination method of first-principles and Boltzmann transport theory. The focus of this article is the systematic study of the thermoelectric properties under the effect of a spin-orbit coupling. The highest dimensionless figure of merit () of CaAuAs at optimum carrier concentration are 1.23 at 700 K. Interestingly enough, for n-type CaHgPb, the maximum are close to each other from 500 K to 900 K and these values are close to 1, which suggests that semimetallic material can also be used as an excellent candidate for thermoelectric materials. From another viewpoint, at room temperature, the maximum PF for CaYZ are greater than 3 mW m K, which is very close to that of ∼3 mW m K for BiTe and ∼4 mW m K for FeVAl. However, the room temperature theoretical of CaYZ is only about 0.85-1.6 W m K, which is comparing to 1.4 W m K for BiTe and remarkably lower than 28 W m K for FeVAl at same temperature. So CaYZ should be a new type of promising thermoelectric material at room temperature.
我们采用第一性原理和玻尔兹曼输运理论相结合的方法，研究了块状CaYZ（Y = Au、Hg；Z = As、Sb、Bi、Sn和Pb）的输运性质。本文的重点是在自旋轨道耦合效应下对热电性质进行系统研究。在最佳载流子浓度下，CaAuAs在700 K时的最高无量纲品质因数（ ）为1.23。有趣的是，对于n型CaHgPb，在500 K至900 K范围内，其最大 值彼此接近且接近1，这表明半金属材料也可作为热电材料的优秀候选者。从另一个角度来看，在室温下，CaYZ的最大功率因子（PF）大于3 mW m K，这与BiTe的约3 mW m K以及FeVAl的约4 mW m K非常接近。然而，CaYZ在室温下的理论 仅约为0.85 - 1.6 W m K，与之相比，BiTe在相同温度下为1.4 W m K，而FeVAl则显著低于28 W m K。因此，CaYZ在室温下应是一种新型的有前景的热电材料。
