Bistable states of defects in graphene

Abstract

Graphene is one of the most promising materials in nanotechnology. The electronic and mechanical properties of graphene samples with high perfection of the atomic lattice are outstanding, but structural defects may change their properties /I/. However, deviations from perfection can be useful in some applications, as they make it possible to glue the local fragments of graphene and to achieve new quality. In the article 111 particular emphasis is put on the unique ability of graphene to reconstruct its lattice around intrinsic defects, leading to interesting effects and potential applications. Defects in graphene were experimentally found 131 and an increase in density of 7r-electron states in the vicinity of such defects was mentioned in 141. It was previously shown (see, e.g., 151) that in the graphene sheet the 5-7 defect being the convexity of the carbon hexagonal lattice leads to the redistribution of 7i-electron charges and to the appearance of the local electric dipole moment. In this work point defects in graphene are considered in the wider frameworks of the carbon surfaces theory. We use the block-regular method, developed by the authors 161. Graphene consists of a hexagonal monolayer network of sp2-hybridized carbon atoms. Defects can also be deliberately introduced into graphene, for example, by irradiation or chemical treatments or by making two- dimensional crystals on special surfaces.