Improvement of electronic and transport properties of graphene nanoribbon by simultaneous substitution of graphane and fluorographane

Abstract

We investigate the electronic and transport properties of the graphene heterostructure nanoribbons terminated by H/H and F/F atoms, which are formed by partially substituting graphane and fluorographane nanoribbons into both edge parts of graphene nanoribbons, using the nonequilibrium Green's functions (NEGF) combined with the density functional theory (DFT). The calculated structural stability shows that all hybrid systems are stable than pristine GNRs. In particular, the hybrid systems terminated by F/F atoms are structurally more favorable than that of H/H ones. Our results indicate that armchair hybrid systems are nonmagnetic semiconductors with wide direct band gaps regardless of their spin polarizations, whereas zigzag systems have the half-metal or half-semiconducting behavior according to their spin polarizations. With the increase of nanoroad, band gaps increase (decrease) to different attributes. Interestingly, h-ZGAx/G8-2xNR/FGxNRs may produce from half-metal to half-semiconducting behavior transition, due to chemical potential change according to ribbon widths and nanoroads. Moreover, the calculated I–V curve exhibits negative differential resistance, which can be used for application in molecular spin electronic device.