Ag纳米线掺杂单晶SnSe热电和力学性能的研究  

Thermoelectric and mechanical properties of Ag nanowire doped single crystal SnSe

作　　者：袁小红 王成江[1] 魏诗蒙 徐晓锐 YUAN Xiaohong;WANG Chengjiang;WEI Shimeng;XU Xiaorui(College of Electrical Engineering&New Energy,China Three Gorges University,Yichang 443000,Hubei Province,China)

机构地区：[1]三峡大学电气与新能源学院,湖北宜昌443000

出　　处：《电子元件与材料》2024年第2期209-216,共8页Electronic Components And Materials

基　　金：国家自然科学基金重点项目(51577105)。

摘　　要：为探究Ag纳米线掺杂对单晶SnSe的热电和力学性能的影响,建立了一种1D-3D的复合结构体系的理论模型。基于密度泛函理论的第一性原理,计算了Ag纳米线掺杂体系的能带、态密度、载流子相对质量、声子群速度及弹性常数等。从微观特征变化研究Ag纳米线掺杂对热电转化性能和力学性能的影响。结果表明:随着Ag纳米线掺杂浓度的增大,体系的禁带宽度逐渐减小,导带有明显的提高,提高了载流子的迁移率,有利于电导率的提高;载流子相对质量呈现先上升后下降的变化趋势,且相较于未掺杂的SnSe有明显增大,材料的塞贝克系数显著提高;声子群速度逐渐减小,导热性能降低,有利于热电性能的提高;掺杂Ag纳米线的SnSe的体模量和剪切模量均比未掺杂的SnSe小,材料的可塑性和韧性逐渐加强,SnSe的力学性能得到改善。In order to investigate the effect of Ag nanowire doping on the thermoelectric and mechanical properties of singlecrystal SnSe,a theoretical model of a 1D-3D composite structural system was developed.The energy bands,density of states,relative mass of carriers,phonon group velocity and elastic constants of the Ag nanowire doped system was calculated based on the first principles of density functional theory.The effects of Ag nanowire doping on the thermoelectric conversion performance and mechanical properties were investigated in terms of microscopic feature variations.The results show that with the increase of Ag nanowire doping concentration,the band gap of the system decreased gradually,and the conduction band had a significant increase,which improved the carrier mobility and was favorable for the increase of electrical conductivity.The relative mass of the carriers showed a trend of increasing first and then decreasing,and compared with the undoped SnSe,the Seebeck coefficient of the material was significantly increased.The phonon group velocity gradually decreased,and the thermal conductivity decreased,which was favorable for the improvement of the thermoelectric properties.The bulk modulus and shear modulus of Ag nanowire doped SnSe were smaller than those of undoped SnSe,and the plasticity and toughness of the material were gradually strengthened,and the mechanical properties of SnSe were improved.

关 键 词：热电材料 第一性原理 AG纳米线 掺杂 热电性能 力学性能 

分 类 号：O482[理学—固体物理]