Rich essential properties of graphene- and silicene-related systems

Abstract

Geometric magnetic and electronic properties of graphene- and silicene-related systems are investigated by the first-principles theoretical framework including the adatom-diversified geometric structure atom-dominated energy bands spatial spin density distributions spatial charge density distributions and its variations and spin- and orbital-projected density of states (DOSs) Such physical quantities are sufficient to identify the critical chemical bondings The essential properties are very sensitive to adatom concentration adatom distributions doping positions various kinds of adatoms The pristine monolayer structure can be deformed buckled non-hexagonal and planar after the adatom adsorption and substitution The critical orbital hybridizations in the C-adatom bondings the Si-adatom bondings the finite-size confinements and the edge structure directly determine the semiconducting semi-metallic and metallic behaviors The diverse spin-dependent electronic properties cover the non-magnetic ferromagnetic and anti-ferromagnetic metals the non-magnetic semiconductors and the anti-ferromagnetic semiconductors with/without spin splitting The developed first-principles theoretical framework can fully be generalized to other 2D layered systems

Date of Award	2019
Original language	English
Supervisor	Min-Fa Lin (Supervisor)