Potential energy surfaces of mechanically induced reconstruction and doping of carbon sp² lattice

Potential energy surfaces of mechanically-induces structural failure and doping by silicon atom of graphene armchair nanoribbon (14 carbon dimers width, 14-AGNR) are studied by ab initio GGA LC DFT technique in combination with Gaussian-type basis set and periodic boundary conditions. Application of external force to a central atom of a perfect graphene nanoribbon leads to ejection of a carbon dimer or pulling out a polycumulene chain. Different mechanisms of mechanical substitution of carbon dimers by η² coordinated silicon are studied. Migration of silicon adatom on graphene and embedding the atom into the lattice at the vicinity of divacancy induces formation of diamagnetic sp²d rectangular planar silicon dopant center. PES of formation of sp²d silicon center consists of several relatively low potential energy barriers, making possible a synthesis of novel 2D materials with unique physical properties.