▎ 摘　　要

Despite the intense interest in peculiar electronic structure of graphene layers for potential application, especially in the microelectronics, the growth mechanism of graphene on substrates is still unclear. Understanding the quantitative correlation between layer number n and the critical radius R-c of the graphene cylinder will provide new insight in the fundamental science for the potential applications of graphene. In this work, the R-c(n) function of graphene layers deposited on SiO2 substrate is established with nanothermodynamics. The finding in which R-c increases linearly as n increases agrees with the experimental results. This reveals the actual mechanism of the graphene growth behavior. In addition, the atomic structure of the graphene/SiO2 interface was optimized by density functional theory.