Disclinations in polycrystalline graphene and pseudo-graphenes. Review

A.E. Romanov ORCID logo , M.A. Rozhkov, A.L. Kolesnikova show affiliations and emails
Received 22 October 2018; Accepted 06 November 2018;
Citation: A.E. Romanov, M.A. Rozhkov, A.L. Kolesnikova. Disclinations in polycrystalline graphene and pseudo-graphenes. Review. Lett. Mater., 2018, 8(4) 384-400
BibTex   https://doi.org/10.22226/2410-3535-2018-4-384-400
Assembling of pseudo-graphene from grain boundaries with structural units 5-7. In this review, we consider wedge disclinations as the main structural defects in 2D graphene crystal hexagonal lattice. Disclinations are associated with improper carbon rings, i.e. rings having 4, 5, 7 or 8 members to the contrary of proper 6-member carbon rings constituting ideal 2D graphene crystal lattice. With the help of disclinations, we build the models for grain boundaries and other interfaces in graphene polycrystals as well as for pseudo-graphenes. The pseudo-graphenes are treated as graphene crystals with high density of periodically distributed disclinations with zero total charge. The geometry and energy of disclinated graphene configurations are analyzed with the help of molecular dynamics (MD) simulation technique and in the framework of the theory of defects in elastic continuum. We demonstrate that the energy of the modeled graphene interfaces reaches the value of 2 eV/Å. For symmetric tilt grain boundaries in graphene the energy stays below 0.5 eV/Å when the boundaries are in so-called equilibrium state. In the case of transition of a grain boundary to non-equilibrium state, the energy of the boundary can be up to three times higher. For investigated pseudo-graphenes, there is substantial energy excess in comparison to conventional grapheme; the found energy excess can be of the order of 1eV per carbon atom. In conclusion, it is argued that studying the properties of disclinations in graphene opens a new direction in graphene science and technology – graphene defect engineering.