Molecular dynamics simulations of nanopore processing in a graphene sheet by using gas cluster ion beam

The formation of a nanopore in a graphene sheet by collision with an argon cluster is simulated using molecular dynamics method. The number of removed carbon atoms and the size of the nanopore are obtained as a function of the kinetic energy of the cluster. In contrast to nanosculpting with a monomer ion beam, the size of the nanopore that is created by one shot of the cluster varies because of the variety of atom configuration. However, the mean size of the nanopore can be controlled over a wide range only by changing the kinetic energy of the cluster. This implies that the cleaning and processing of the graphene sheet may be realized simultaneously by changing the acceleration energy of the cluster.