晶界几何结构对纳晶ZnO材料导热过程的影响  

Effect of Grain Boundary Geometry on the Thermal Conduction of Nanocrystalline ZnO

作　　者：刘英光[1] 韩笑[1] 郝将帅 Liu Yingguang;Han Xiao;Hao Jiangshuai(North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学,河北保定071003

出　　处：《稀有金属材料与工程》2021年第3期924-931,共8页Rare Metal Materials and Engineering

基　　金：中央高校基本科研业务费(2020MS105)。

摘　　要：为了探究晶界几何结构对纳晶ZnO材料导热性能的影响,将晶界表面抽象出几种典型几何形状,深入讨论了晶界表面粗糙度的计算以及声子入射角对镜面反射率的影响,改进了晶界镜面反射率的计算模型。采用PhonTS软件,用迭代法求解玻尔兹曼输运方程模拟计算得到了纳晶ZnO晶格热导率。基于分子动力学理论计算了ZnO完美材料的热导率,分析了镜面反射率、声子入射角、晶粒尺寸等因素对热导率的影响。结果表明:晶界表面粗糙度的减小或声子入射角的增大会使晶界镜面反射率增大;声子在晶界发生镜面反射不会产生热阻,纳晶材料的热导率会随着镜面反射率的增大而增大;纳晶ZnO材料的热导率表现出强烈的尺寸效应,尺寸效应随着晶粒尺寸的增大而减小。Nanocrystalline Zn O is widely used in the field of microelectronics, and its thermal conductivity has an important effect on the performance of electronic devices. In order to explore the effect of grain boundary geometry on the thermal conduction of nanocrystalline Zn O, the grain boundary geometries were abstracted into several typical structures. On this basis, the calculation of grain boundary surface roughness was conducted and the effect of phonon incident angle on specular reflectance was discussed, and the calculation model of grain boundary specular reflectance was improved. Phon TS software was used to solve the Boltzmann transport equation iteratively to obtain the perfect lattice thermal conductivity of nanocrystalline Zn O. The thermal conductivity of nanocrystal Zn O was calculated based on the molecular dynamics theory, and effects of specular reflectance, phonon incident angle and grain size on the thermal conductivity were analyzed. The results show that the decrease of grain boundary surface roughness or the increase of phonon incident angle will increase the specular reflectance of grain boundary;phonon specular reflectance at grain boundary will not generate thermal resistance, and the thermal conductivity of nanocrystalline materials increases with the increase of specular reflectance;the thermal conductivity of nanocrystalline Zn O shows a strong size effect, which decreases with the increase of grain size.

关 键 词：纳晶ZnO 热导率 镜面反射 尺寸效应 

分 类 号：TB383[一般工业技术—材料科学与工程]