Li Gan, Huang Sheng-Hong, Li Zhenyu
Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
Phys Chem Chem Phys. 2015 Sep 21;17(35):22832-6. doi: 10.1039/c5cp02301g.
Chemical vapour deposition on a Cu substrate is becoming a very important approach to obtain high quality graphene samples. Previous studies of graphene growth on Cu mainly focus on surface processes. However, recent experiments suggest that gas-phase dynamics also plays an important role in graphene growth. In this article, gas-phase processes are systematically studied using computational fluid dynamics. Our simulations clearly show that graphene growth is limited by mass transport under ambient pressures while it is limited by surface reactions under low pressures. The carbon deposition rate at different positions in the tube furnace and the concentration of different gas phase species are calculated. Our results confirm that the previously realized graphene thickness control by changing the position of the Cu foil is a result of gas-phase methane decomposition reactions.
在铜衬底上进行化学气相沉积正成为获得高质量石墨烯样品的一种非常重要的方法。先前关于在铜上生长石墨烯的研究主要集中在表面过程。然而，最近的实验表明，气相动力学在石墨烯生长中也起着重要作用。在本文中，使用计算流体动力学对气相过程进行了系统研究。我们的模拟清楚地表明，在环境压力下石墨烯生长受质量传输限制，而在低压下受表面反应限制。计算了管式炉中不同位置的碳沉积速率以及不同气相物种的浓度。我们的结果证实，先前通过改变铜箔位置实现的石墨烯厚度控制是气相甲烷分解反应的结果。
