Structural and Electronic Properties of Hybrid Fluorographene-Graphene Nanoribbons: Insight from First-Principles Calculations

The first-principles calculations have been used to investigate the structural and electronic properties of fluorographene nanoribbons and hybrid fluorographene-graphene nanoribbons. Our results indicate that both zigzag and armchair fluorographene nanoribbons are always semiconductors with width-dependent band gaps. The zigzag hybrid nanoribbons with F-terminated graphene edge are half-semiconductors with the two spin channels having a different band gap, qualitatively different from the graphene nanoribbons and hybrid graphane-graphene nanoribbons. The electronic properties of partially fluorinated zigzag graphene nanoribbons were well tuned by edge chemical modification and by control of the number of fluorinated zigzag carbon chains. With NH2 or CH3 groups passivating the graphene side edge, the half-metallicity in zigzag hybrid nanoribbons was realized. Interestingly, the partially fluorinated zigzag graphene nanoribbons with NH2 and CH3 groups may produce half-metallic -> half-semiconducting behavior transition when the fluorographene widths gradually increase due to the chemical potential difference change. Therefore, fluorination of graphene nanoribbons will provide a novel way to tune the properties with potential applications to nanotechnology.