物理学报2024，Vol.73Issue(15)：9-18,10.DOI:10.7498/aps.73.20240515
基于分子动力学的氮化镓/石墨烯/金刚石界面热导研究
Interfacial thermal conductance of gallium nitride/graphene/diamond heterostructure based on molecular dynamics simulation
摘要
Abstract
Gallium nitride chips are widely used in high-frequency and high-power devices.However,thermal management is a serious challenge for gallium nitride devices.To improve thermal dissipation of gallium nitride devices,the nonequilibrium molecular dynamics method is employed to investigate the effects of operating temperature,interface size,defect density and defect types on the interfacial thermal conductance of gallium nitride/graphene/diamond heterostructure.Furthermore,the phonon state densities and phonon participation ratios under various conditions are calculated to analyze the interface thermal conduction mechanism. The results indicate that interfacial thermal conductance increases with temperatures rising,highlighting the inherent self-regulating heat dissipation capabilities of heterogeneous.The interfacial thermal conductance of monolayer graphene structures is increased by 2.1 times as the temperature increases from 100 to 500 K.This is attributed to the overlap factor increasing with temperature rising,which enhances the phonon coupling between interfaces,leading the interfacial thermal conductance to increase. Additionally,in the study it is found that increasing the number of layers of both gallium nitride and graphene leads the interfacial thermal conductance to decrease.When the number of gallium nitride layers increases from 10 to 26,the interfacial thermal conductance decreases by 75%.The overlap factor diminishing with the layer number increasing is ascribed to the decreased match of phonon vibrations between interfaces,resulting in lower thermal transfer efficiency.Similarly,when the number of graphene layers increases from 1 to 5,the interfacial thermal conductance decreases by 74%.The increase in graphene layers leads the low-frequency phonons to decrease,consequently lowering the interfacial thermal conductance.Moreover,multilayer graphene enhances phonon localization,exacerbates the reduction in interfacial thermal conductance. It is found that introducing four types of vacancy defects can affect the interfacial thermal conductance.Diamond carbon atom defects lead its interfacial thermal conductance to increase,whereas defects in gallium,nitrogen,and graphene carbon atoms cause their interfacial thermal conductance to decrease.As the defect concentration increases from 0 to 10%,diamond carbon atom defects increase the interfacial thermal conductance by 40%due to defect scattering,which increases the number of low-frequency phonon modes and expands the channels for interfacial heat transfer,thus improving the interfacial thermal conductance.Defects in graphene intensify the degree of graphene phonon localization,consequently leading the interfacial thermal conductance to decrease.Gallium and nitrogen defects both intensify the phonon localization of gallium nitride,impeding phonon transport channels.Moreover,gallium defects induce more severe phonon localization than nitrogen defects,consequently leading to lower interfacial thermal conductance. This research provides the references for manufacturing highly reliable gallium nitride devices and the widespread use of gallium nitride heterostructures.关键词
界面热导/温度效应/尺寸效应/空位缺陷Key words
interface thermal conductance/temperature effect/size effect/vacancy defect引用本文复制引用
刘东静,胡志亮,周福,王鹏博,王振东,李涛..基于分子动力学的氮化镓/石墨烯/金刚石界面热导研究[J].物理学报,2024,73(15):9-18,10.基金项目
广西制造系统与先进制造技术重点实验室主任基金(批准号:19-050-44-002Z)、2024 年度广西高校中青年教师科研基础能力提升项目(批准号:2024KY0203)、桂林电子科技大学研究生教育创新计划(批准号:2024YCXS016)和 2023年广西自治区级新工科研究与实践项目(批准号:XGK202309)资助的课题.Project supported by the Guangxi Key Laboratory of Manufacturing System&Advanced Manufacturing Technology,China(Grant No.19-050-44-002Z),the 2024 Project on Enhancement of Basic Research Ability for Young and Middle-aged Teachers in Guangxi Universities,China(Grant No.2024KY0203),the Innovation Project of Graduate Education of Guilin University of Electronic Science and Technology,China(Grant No.2024YCXS016),and the 2023 Guangxi Autonomous Region New Engineering Research and Practice Project,China(Grant No.XGK202309). （批准号:19-050-44-002Z）
