物理化学学报 >> 2022, Vol. 38 >> Issue (1): 2012006.doi: 10.3866/PKU.WHXB202012006

所属专题: 石墨烯的功能与应用

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金属衬底在石墨烯化学气相沉积生长中的作用

程婷1,2, 孙禄钊1,2, 刘志荣1, 丁峰3,4,*(), 刘忠范1,2,*()   

  1. 1 北京大学纳米化学研究中心,北京分子科学国家研究中心,北京大学前沿交叉学科研究院,北京大学化学与分子工程学院,北京 100871
    2 北京石墨烯研究院,北京 100095
    3 基础科学研究所多维碳材料中心,蔚山 44919,韩国
    4 蔚山国立科技大学材料科学与工程学院,蔚山 44919,韩国
  • 收稿日期:2020-12-02 录用日期:2020-12-25 发布日期:2020-12-30
  • 通讯作者: 丁峰,刘忠范 E-mail:f.ding@unist.ac.kr;zfliu@pku.edu.cn
  • 作者简介:丁峰,1970年出生,2002年获南京大学博士学位。现为韩国蔚山国立科技大学杰出教授,韩国基础科学院多维碳材料中心理论组组长。目前的主要研究方向为低维材料的理论研究
    刘忠范,1962年出生,1990年获东京大学博士学位。现为北京大学教授,博士生导师,北京石墨烯研究院院长,中国科学院院士。主要研究方向为石墨烯的CVD生长方法与应用第一联系人:

    These authors contributed equally to this work.

  • 基金资助:
    国家重点研发计划(2016YFA0200101);国家自然科学基金(21773002);北京分子科学国家研究中心(BNLMS-CXTD-202001);北京市科学技术委员会(Z181100004818001);北京市科学技术委员会(Z191100000819005);北京市科学技术委员会(Z201100008720005)

Roles of Transition Metal Substrates in Graphene Chemical Vapor Deposition Growth

Ting Cheng1,2, Luzhao Sun1,2, Zhirong Liu1, Feng Ding3,4,*(), Zhongfan Liu1,2,*()   

  1. 1 Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, Academy for Advanced Interdisciplinary Studies, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
    2 Beijing Graphene Institute (BGI), Beijing 100095, China
    3 Centre for Multidimensional Carbon Materials, Institute for Basic Science, Ulsan 44919, Korea
    4 School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
  • Received:2020-12-02 Accepted:2020-12-25 Published:2020-12-30
  • Contact: Feng Ding,Zhongfan Liu E-mail:f.ding@unist.ac.kr;zfliu@pku.edu.cn
  • About author:Zhongfan Liu, Email: zfliu@pku.edu.cn
    Feng Ding, Email: f.ding@unist.ac.kr
  • Supported by:
    the National Key R & D Program of China(2016YFA0200101);the National Natural Science Foundation of China(21773002);the Beijing National Laboratory for Molecular Sciences, China(BNLMS-CXTD-202001);the Beijing Municipal Science & Technology Commission, China(Z181100004818001);the Beijing Municipal Science & Technology Commission, China(Z191100000819005);the Beijing Municipal Science & Technology Commission, China(Z201100008720005)

摘要:

以过渡金属为催化衬底的化学气相沉积法(Chemical Vapor Deposition,CVD)已经可以制备与机械剥离样品相媲美的石墨烯,是实现石墨烯工业应用的关键技术之一。原子尺度理论研究能够帮助我们深刻理解石墨烯生长机理,为实验现象提供合理的解释,并有可能成为将来实验设计的理论指导。本文从理论计算的角度,总结了各种金属衬底在石墨烯CVD生长过程中的各种作用与相应的机理,包括在催化碳源裂解、降低石墨烯成核密度等,催化加快石墨烯快速生长,修复石墨烯生长过程中产生的缺陷,控制外延生长石墨烯的晶格取向,以及在降温过程中石墨烯褶皱与金属表面台阶束的形成过程等。在本文最后,我们对当前石墨烯生长领域中亟需解决的理论问题进行了深入探讨与展望。

关键词: 石墨烯, 化学气相沉积, 外延, 催化, 第一性原理计算

Abstract:

Graphene has attracted great attention owing to its excellent physical and chemical properties and potential applications. Presently, we can grow large-scale single-crystal graphene on transition metal substrates, especially Cu(111) or CuNi(111) surfaces, using the chemical vapor deposition (CVD) method. To optimize graphene synthesis for large-scale production, understanding the growth mechanism at the atomic scale is critical. Herein, we summarize the theoretical studies on the roles of the metal substrate in graphene CVD growth and the related mechanisms. Firstly, the metal substrate catalyzes the carbon feedstock decomposition. The dissociation of CH4, absorption, and diffusion of active carbon species on various metal surfaces are discussed. Secondly, the substrate facilitates graphene nucleation with controllable nucleation density. The dissociation and diffusion of carbon atoms on the CuNi alloy surface with different Ni compositions are revealed. The metal substrate also catalyzes the growth of graphene by incorporating C atoms from the substrate into the edge of graphene and repairing possible defects. On the most used Cu(111), each armchair site on the edge of graphene is intended to be passivated by a Cu atom and lowers the barrier of incorporating C atoms into the graphene edge. The potential route of healing the defects during graphene CVD growth is summarized. Moreover, the substrate controls the orientation of the epitaxial graphene. The graphene edge-catalyst interaction is strong and is responsible for the orientation determination of a small graphene island in the early nucleation stage. There are three modes for graphene growth on metal substrate, i.e. embedded mode, step-attached mode and on-terrace mode, and the preferred growth modes are not all alike but vary from metal to metal. On a soft metal like Cu(111), graphene tends to grow in step-attached or embedded modes and therefore has a fixed orientation relative to the metal crystal lattice. Finally, the formation of wrinkles and step bunches in graphene because of the difference in thermal expansion coefficients between graphene and the metal substrate is discussed. The large friction force and strong interaction between graphene and the substrate make it energetically unfavorable for the formation of wrinkles. Different from the formation of wrinkles, the main driving force behind metal surface step-bunching in CVD graphene growth, even in the absence of a compression strain is revealed. Although significant effort is still required to adequately understand graphene catalytic growth, these theoretical studies offer guidelines for experimental designs. Furthermore, we provide the key issues to be explored in the future.

Key words: Graphene, Chemical vapor deposition, Epitaxy, Catalysis, First-principle calculations

MSC2000: 

  • O647