HOW TO FABRICATE NEW CARBON NANOSTRUCTURES THROUGH GRAIN BOUNDARY ENGINEERING IN GRAPHENE

Conventional curved carbon nanostructures such as fullerenes, capped nanotubes and cones can be produced by insertion of pentagons - sources of highly concentrated curvature - into initially flat hexagonal lattice of single crystalline graphene. This paper is focused on a new approach (suggested and briefly discussed earlier [IA. Ovid'ko // Rev. Adv. Mater. Sci. 30 (2012) 2011) which potentially allows one to fabricate principally new curved carbon nanostructures with arbitrary geometries/shapes. The approach represents insertion of special defects into grain boundaries (GBs) of initially flat polycrystalline graphene. Since special defects typically serve as flexible sources of weakly concentrated curvature, this approach opens intriguing possibilities to fabricate new carbon nanostructures with novel properties controlled by their curvature. In particular, elastic strains created by weakly varying curvature in polycrystalline graphene can effectively tailor its electronic properties and thus be exploited in electronics based on design of moderately curved graphene. Also, in this paper, technological schemes/strategies are outlined which can be potentially exploited in the fabrication of new curved carbon nanostructures through GB engineering in graphene.