当前位置: X-MOL 学术Adv. Electron. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Ultralow Thermal Conductivity in Dual‐Doped n‐Type Bi2Te3 Material for Enhanced Thermoelectric Properties
Advanced Electronic Materials ( IF 5.3 ) Pub Date : 2021-01-12 , DOI: 10.1002/aelm.202000910
Jamal‐Deen Musah 1 , Chen Guo 2 , Andrei Novitskii 3 , Illia Serhiienko 3 , Ayotunde Emmanuel Adesina 2 , Vladimir Khovaylo 3 , Chi‐Man Lawrence Wu 2 , Juan Antonio Zapien 2 , Vellaisamy A. L. Roy 4
Affiliation  

Bismuth chalcogenides are promising materials for thermoelectric (TE) application due to their high power factor (product of the square of the Seebeck coefficient and electrical conductivity). However, their high thermal conductivity is an issue of concern. Single doping has proven to be useful in improving TE performance in recent years. Here, it is shown that dual isovalent doping shows the synergistic effect of thermal conductivity reduction and electron density control. The insertion of large atoms in the layered Bi2Te3 structure distorts the crystal lattice and contributes significantly to phonon scattering. The ultralow thermal conductivity (KT = 0.35 W m−1 K−1 at 473 K) compensates for the low power factor and thus enhances TE performance. The density functional theory electronic structure calculation results reveal deep defects states in the valence band, which influences the electronic transport properties of the system. Therefore, the dual dopants (indium and antimony) show a coupled effect of improvement in the density of state near the Fermi level and reduction in the conduction band minimum, thus enhancing electron density. Numerically, it is demonstrated that the dual doping favors acoustic phonon scattering and thus drastically reduces the thermal conductivity.

中文翻译:

双掺杂n型Bi2Te3材料的超低导热性可增强热电性能

铋硫属化物因其高功率因数(塞贝克系数和电导率的乘积)而成为有希望用于热电(TE)应用的材料。但是,它们的高导热率是一个值得关注的问题。近年来,单掺杂已被证明可用于改善TE性能。在此,表明双等价掺杂显示出热导率降低和电子密度控制的协同效果。在层状Bi 2 Te 3结构中插入大原子会扭曲晶格,并显着促进声子散射。超低热导率(K T = 0.35 W m -1 K -1在473 K时)补偿了低功率因数,从而提高了TE性能。密度泛函理论的电子结构计算结果揭示了价带中的深缺陷状态,这影响了系统的电子传输性能。因此,双重掺杂剂(铟和锑)显示出改善费米能级附近的状态密度和减小导带最小值的耦合作用,从而提高了电子密度。从数值上证明,双重掺杂有利于声子的声子散射,因此大大降低了热导率。
更新日期:2021-02-15
down
wechat
bug