Molecular dynamics simulation of the amorphous graphite-like membrane deposited on ideal graphite substrate

Abstract

To understand the growth mechanism of pyrolytic graphite on ideal graphite substrate by chemical vapor deposition (CVD), the process simulated by molecular dynamics is performed. The simulation revealed that only an amorphous graphite-like membrane (a-GLM) can be obtained using the Tersoff potential function. It is revealed that the formation process for the first layer of the a-GLM initiates from the firstly deposited carbon monomers, dimers, and trimers as growth points, on which Y-shaped long chain is formed, and then the network with pores are developed, and finally the graphene-like layer with six-membered dominated rings appears after repair treatment. The following deposition simulation for more deposited carbon atoms indicates that a second layer like-graphene is more prone to superpose onto the microdomains of the first layer like-graphene until the formation of the island-like bumps, and the concave zone around the bumps will be filled by deposited atoms and modified by defect repair. The growth mechanism for pyrolytic graphite prepared by CVD can be deduced by the simulation inspiration. The optimal deposition temperature of 2400 K is acquired by evaluating the integrity of the first deposited graphene film by statistics of five-to-seven-membered carbon ring number. This study can provide theoretical references for the design of the pyrolytic graphite production process.