Abstract
Graphene grown on a substrate is likely to be polycrystalline. Defects consisting of pentagons or heptagons of C atoms make rows at grain boundaries in such polycrystalline graphene. In this paper, the tensile strength of polycrystalline graphene is investigated using the method of atomistic simulation. Simulation models are constructed by connecting two rectangular graphene-flakes possessing different crystallographic directions. Firstly, these models are relaxed without strain. Next, these models are forced to be uniaxially-strained in the direction perpendicular to the grain boundary. The stress-strain relation and energy distribution of polycrystalline graphene under strains are obtained. Furthermore, its fracture mechanism is examined.
