Mechanical properties of graphene grain boundary and hexagonal boron nitride lateral heterostructure with controlled domain size

Abstract

In this paper, the mechanical properties of in-plane heterostructure with alternating stripes of graphene grain boundary (GB) and hexagonal boron nitride (h-BN) are investigated using classical Molecular Dynamics method. The graphene GB contains an array of pentagon-heptagon (5–7) defects, and has good interfacial continuity with the lateral BN domain. By studying the dynamic failure process of heterostructure with varying hybridization intervals and GB tilt angles, two different local failure types are noticed. Coupled effects of h-BN hybridization and GB tilt angle on the tensile strength of heterostructure are revealed. For heterostructure with graphene GBs of evenly spaced 5–7 defects, the tensile strength is insensitive to the h-BN hybridization and increases anomalously with the defect density. For heterostructure with graphene GB of unevenly spaced 5–7 defects, lateral h-BN hybridization enhanced the tensile strength of the heterostructure. Such strength enhancement effect is contributed to the bond length mismatch between graphene and h-BN, and deteriorates with the increase of hybridization interval. Our results give helpful insight into the strength characteristics of hybrid two-dimensional nanomaterials based electronic and optical devices.