Bi_4Se_3薄膜的声子结构及电声子相互作用的第一性原理研究  

Phonon Structure and Electron-phonon Interaction in Bi_4Se_3 Film:First-principles Study

作　　者：刘霞[1] 杜晓[1] 张骏杰[1] 黄桂芹[1] LIU Xia DU Xiao ZHANG Junjie HUANG Guiqin(Department of Physics, Nanjing Normal University, Nanjing 210023, China)

机构地区：[1]南京师范大学物理科学与技术学院,江苏南京210023

出　　处：《计算物理》2016年第4期483-489,共7页Chinese Journal of Computational Physics

基　　金：江苏省自然科学基金(BK20141441)资助项目

摘　　要：基于密度泛函微扰理论,运用第一性原理研究两种终结面的Bi_4Se_3薄膜的声子结构和电-声子相互作用.结果表明两种终结面的Bi_4Se_3薄膜体系都是动力学稳定的.Bi_4Se_3薄膜中插入的Bi2双原子层与Bi2Se3五原子层的声子投影态密度并不完全匹配,这会阻碍部分声子的输运,降低热导,从而有利于提高材料的热电性能.另外,两种终结面的Bi_4Se_3薄膜的电-声子耦合系数都不太大(约0.278),有利于制备基于室温工作的电子学器件.Based on density functional perturbation theory, phonon properties and electron-phonon interaction in Bi4 Se3 film system are studied with first-principles calculations. It shows that dynamic of Bi4 Se3 film system for two terminations is stable. There exists mismatch in projected phonon density of states between Bi2 bilayer and Bi2 Se3 quintuple layer. It prevents part phonons to transport in Bi4 Se3 film, which leads to thermal conductivity reduce and improves thermoelectric performance of material. Besides, electron-phonon coupling constant of Bi4Se3 film in two kinds of termination are small （about 0-278）, which is in favour of electronic device in room temperature.

关 键 词：第一性原理 声子结构 电-声子耦合 

分 类 号：O469[理学—凝聚态物理]