▎ 摘　　要

Scalable large graphene single crystals have been synthesized by using a backward faced quartz cuvette in a conventional tube furnace. The effect of the restricted chamber in controlling the graphene single crystal growth has been systematically studied by considering the influence of the flow rate and ratio of H-2 and CH4 experimentally. Numerical simulations were performed to uncover the underlying mechanism. The convection of CH4 was substantially suppressed inside the cuvette due to the blocking effect by the close-end geometry. The diffusivity of CH4 is much lower than that of H-2, resulting in a slow transportation of CH4 as well. By using the specific experimental parameters, the mass ratio of H-2 and CH4 increased about 3 times inside the cuvette, leading to preferential growth of graphene single crystals, as observed in our experiments. Meanwhile, the growth of a second layer can be suppressed by the slower feeding of CH4 than H-2. Based on these results, we believe that setup of our restricted chamber can provide another growth approach for scalable graphene single crystals and its analysis can help understand more growth dynamics of graphene single crystal inside other irregular CVD conditions such as rolled-up and enclosed Cu foils. (C) 2015 Published by Elsevier Ltd.