A key factor improving the thermoelectric properties of Zintl compounds A5M2Pn6 (A = Ca, Sr, Ba; M = Ga, Al, In; Pn = As, Sb)
A key factor improving the thermoelectric properties of Zintl compounds A5M2Pn6 (A = Ca, Sr, Ba; M = Ga, Al, In; Pn = As, Sb)
复制标题
提高Zintl化合物热电性能的关键因素A(5)M(2)Pn(6) (A = Ca, Sr, Ba; M = Ga, Al, In; Pn = As, Sb)
DOI：
10.1016/j.commatsci.2013.12.049
复制
发表时间：
2014-04-01
影响因子：
3.3
通讯作者：
Zhang, Guang Biao
中科院分区：
文献类型：
--
作者：
Yan, Yu Li;Wang, Yuan Xu;Zhang, Guang Biao
分别用第一性原理计算和玻耳兹曼输运理论研究了A(5)M(2)Pn(6)(A=Ca，Sr，Ba；M=Ga，Al，In；Pn=As，Sb)的电子结构和输运性质。结果表明，这些带隙的宽度大小顺序为：Ca5Ga2As6(0.37 eV)>；Ca5Al2Sb6(0.35 eV)>；Ca5In2Sb6(0.32 eV)>；Sr5In2Sb6(0.29 eV)>；Ba5In2Sb6(0.27 eV)>；Ca5Ga2Sb6(0.088 eV)。对于本征A(5)M(2)Pn(6)，增大禁带宽度有利于改善其热电性能。对于掺杂的A(5)M(2)Pn(6)，增加禁带宽度有助于改善A(5)M(2)Pn(6)的高温热电性能。然而，在300K，当带隙足够小时，无论是n型还是p型掺杂，A(5)M(2)Pn(6)都表现出良好的热电性能。我们的分析表明，可以通过改变Pn和A之间的电负性差来大致调整带隙，而通过改变Pn和M原子之间的电负性差来微妙地调整带隙。因此组成元素之间的电负性差异是影响热电性能的一个非常重要的因素。(C)2014爱思唯尔B.V.保留所有权利。
The electronic structure and transport properties of A(5)M(2)Pn(6) (A = Ca, Sr, Ba; M = Ga, Al, In; Pn = As, Sb) are investigated by using the first-principles calculations and Boltzmann transport theory, respectively. The results show that the order of the width of these band gaps is Ca5Ga2As6 (0.37 eV) > Ca5Al2Sb6 (0.35 eV) > Ca5In2Sb6 (0.32 eV) > Sr5In2Sb6 (0.29 eV) > Ba5In2Sb6 (0.27 eV) > Ca5Ga2Sb6 (0.088 eV). For intrinsic A(5)M(2)Pn(6), increasing the band gap is better for improving their thermoelectric properties. For doped A(5)M(2)Pn(6), increasing the band gap is helpful to improve the high-temperature thermoelectric properties of A(5)M(2)Pn(6). However, at 300 K, when the band gap is small enough, regardless of n-type or p-type doping, A(5)M(2)Pn(6) exhibits good thermoelectric properties. Our analysis shows that the band gaps can be roughly adjusted by changing the electronegativity difference between Pn and A, and subtly adjusted by changing the electronegativity difference between Pn and M atoms. So the electronegativity difference among the constituent element is a very important factor affecting the thermoelectric properties. (C) 2014 Elsevier B.V. All rights reserved.