摘要
碲(Te)是一种良好的单质热电(TE)材料,具有很高的Seebeck系数和载流子迁移率,以及非常低的热导率。本工作采用热压法制备了Te以及Sb掺杂的Te多晶,采用垂直布里奇曼下降法制备了Te晶体,并对得到的晶体进行热电性能测试研究。结果表明:Te具有高的Seebeck系数以及电导率,Sb掺杂有效提高了Te的热电性能,由布里奇曼法制备的Te晶体的电导率表现出明显的各向异性。这主要归因于Te具有简并的能带、阶梯状的态密度分布和超大的声子散射相。然而这些有益于热电传输的特征又都源自于Te晶格中的孤对电子。本工作展示了孤对电子与各热电传输性能之间的联系,为热电参数解耦提供了一种新的方法,同时也为寻找优异的热电材料提供了思路。
Tellurium is an excellent thermoelectric(TE)material,has very high Seebeck coefficient,mobility and extra low thermal conductivity.In this paper,polycrystalline samples of pure Te and Sb x Te 1-x were prepared using melt-alloying and hot-pressing techniques,and Te crystals were prepared by vertical Bridgman-Stockbarge method.Then thermoelectric properties of the obtained crystals were studied.The results show that Te has a high Seebeck coefficient and conductivity,and Sb doping effectively improves the thermoelectric properties of Te,the conductivity of Te crystals prepared by vertical Bridgman-Stockbarge method shows obvious anisotropy.These results are mainly attributed to degenerate band in valance band,step-like DOS distribution near Fermi level and large phonon scattering phase.This effect can be attributed to the lone-pair electrons in Te lattice,which enable these characters benefiting TE transport properties.This study illustrates the lone-pair electrons of Te are origins of these properties by decouplingσ,αandκ,which also offer a new character to look for good TE materials.
作者
李蓉
陈少平
樊文浩
陈彦佐
徐礼彬
王文先
吴玉程
LI Rong;CHEN Shaoping;FAN Wenhao;CHEN Yanzuo;XU Libin;WANG Wenxian;WU Yucheng(College of Material Science and Engineering,Taiyuan University of Technology,Taiyuan 030024;College of Physics and Optoelectronics,Taiyuan University of Technology,Taiyuan 030024)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第21期3726-3730,共5页
Materials Reports
关键词
碲
孤对电子
热电传输
锑掺杂
垂直布里奇曼下降法
各向异性
tellurium
lone-pair electrons
thermoelectric transmission
antimony doping
vertical Bridgman-Stockbarge method
anisotropy
作者简介
李蓉:女,1994年生,硕士研究生,研究方向为半导体热电材料 E-mail:18334707086@163.com;陈少平:通信作者,女,1977年生,博士,教授,从事半导体热电材料研究 E-mail:sxchenshaoping@163.com。
