Chemically tuning mechanics of graphene by BN

With finite bandgaps, g-BNC, a boron nitride monolayer (g-BN) phase within a graphene layer, is a promising semiconductor for next generation electronics. We report its mechanics dependence of the g-BN concentration, including the high order elastic constants and mechanical failure, through a first-principles study based on density functional theory. The in-plane stiffness as well as third order elastic constants of graphene can be linearly tuned with g-BN concentration. The longitudinal mode elastic constants are sensitive to the BN modification, in contrast to the shear mode elastic constants. This study may provide guidance in optimizing the mechanics of graphene-based nanodevices. The mechanical properties of graphene are modified by g-BN concentration, providing guidance to optimize graphene-based nanodevices. The in-plane stiffness and third order elastic constants can be linearly tuned. The longitudinal mode elastic constants are sensitive to the BN modification. The third, fourth, and fifth order elastic constants are required for strains larger than 0.02, 0.06, and 0.12, respectively.