School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
Sichuan Branch of Meteorological Training Institute CMA, Chengdu, 610072, China.
Sci Rep. 2017 Aug 15;7(1):8244. doi: 10.1038/s41598-017-08159-8.
Graphene, a two-dimensional material, has a wide range of unique properties and could be used in the development of varieties of mechanic, electronic and photonic devices, therefore methods to synthesis large-area high-quality graphene films are urgently required. Chemical vapor deposition (CVD) has been of particular interest recently due to its simplicity and low cost. However, because of the mismatch of thermal expansion coefficients, high densities of wrinkles are commonly observed. Despite their prevalence and potential impact on large-scale graphene properties, relatively little is known about their structural morphology and formation mechanism. In this article, morphologies of graphene obtained by CVD are experimentally investigated by an atomic force microscope (AFM) and results show that the profiles of wrinkles are much larger than they should be. By using theoretical methods and molecular dynamics simulations (MD), we find internal molecules created during CVD process which supply additional pressure is the main mechanism.
石墨烯是一种二维材料，具有广泛的独特性质，可用于开发各种力学、电子和光子器件，因此迫切需要开发大面积高质量石墨烯薄膜的合成方法。化学气相沉积（CVD）由于其简单性和低成本而受到特别关注。然而，由于热膨胀系数不匹配，通常会观察到高密度的褶皱。尽管它们普遍存在且可能对大规模石墨烯性能产生影响，但人们对它们的结构形态和形成机制知之甚少。在本文中，通过原子力显微镜（AFM）对 CVD 获得的石墨烯形貌进行了实验研究，结果表明褶皱的轮廓远大于应有的轮廓。通过使用理论方法和分子动力学模拟（MD），我们发现 CVD 过程中产生的内部分子提供了额外的压力，这是主要的机制。
