基于分子动力学模拟的铜晶面石墨烯沉积生长机理  

Deposition and growth mechanism of graphene on copper crystal surface based on molecular dynamics simulation

作　　者：白清顺[1] 窦昱昊 何欣[1] 张爱民 郭永博[1] Bai Qing-Shun;Dou Yu-Hao;He Xin Zhang;Ai-Min;Guo Yong-Bo(School of Mechanical and Electrical Engineering,Harbin Institute of Technology,Harbin 150000,China)

机构地区：[1]哈尔滨工业大学机电工程学院,哈尔滨150000

出　　处：《物理学报》2020年第22期342-350,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51775146,51535003)资助的课题。

摘　　要：化学气相沉积法是大面积、高质量石墨烯沉积制备实践中的重要方法.本文采用分子动力学仿真技术,模拟了利用化学气相沉积法在铜(111)晶面制备石墨烯的过程,研究揭示了石墨烯在铜(111)晶面上的微观生长机理.研究结果表明:石墨烯的沉积生长可描述为第一阶段的二元碳、三元碳和碳链形成阶段,以及第二阶段的碳环生成以及缺陷愈合阶段.研究发现沉积过程中的高温能够给碳原子提供足够的能量,使其越过两个阶段之间的能量障碍,实现石墨烯的沉积生长.探究了温度与碳沉积速率对石墨烯的影响,发现温度的影响主要体现在石墨烯的缺陷以及表面平整度两个方面.在1300 K的温度下生长的石墨烯缺陷较少,平整度最好.碳沉积速率会影响石墨烯生长过程中出现的缺陷,仿真获得了石墨烯最佳表面平整度时的碳沉积速率为5 ps^–1.本文的研究结果对铜基底表面化学气相沉积法制备石墨烯的实际应用具有指导意义.Chemical vapor deposition(CVD)is an essential method of depositing and fabricating large-area and highquality graphene.In this work,molecular dynamics(MD)simulation technology is adopted to simulate the fabrication of graphene on the copper(111)crystal surface by chemical vapor deposition method.In order to eliminate the adverse effects of traditional MD method,an adapted potential system between carbon and copper atoms is introduced into the modeling of deposition and growth simulation of graphene.The results reveal the microscale growth mechanism of the graphene depositing on Cu(111)crystal surfaces,and the influence of temperature and carbon deposition rate(CDR)on the quality of graphene.The simulation results indicate that the deposition and growth of graphene consists of two stages.The first stage is to form binary carbons,trinary carbons and carbon chains.The second stage is to form carbon rings and the defects healing.The research results also reveal that high temperature can provide the carbon atoms with sufficient energy,which can help the carbon atoms to skip the energetic barrier between the two stages,and then achieve the deposition and growth of graphene.Moreover,the influence of temperature and carbon deposition rate are investigated in detail.The temperature mainly affects the defects and the flatness of graphene.The defects of graphene are the least and the surface can become the flattest at a deposition temperature of 1300 K.Higher temperature can cause the carbon atoms to irregularly move,and lower temperature can suppress the catalysis of the copper substrate.Both the higher and lower temperature can degrade the quality of the graphene surface.The CDR can influence the defects of graphene in growth.The lower value of CDR can lead to local growth on the graphene surface because of the lower nucleation density while the higher CDR is also able to cause the defects to form because of the uneven free energy distribution on the copper surface that has thermal fluctuation.It is shown that graphene ca

关 键 词：石墨烯 分子动力学 沉积生长 机理 

分 类 号：O613.71[理学—无机化学]