Spin-Polarized Transport Behavior Induced by Asymmetric Edge Hydrogenation in Hybridized Zigzag Boron Nitride and Graphene Nanoribbons

Abstract

We fused zigzag graphene to boron nitride nanoribbons by gradually doping C atoms at only one edge of the ribbons to design a hybridized ZBxNyCz (x + y + z = 12) structure. To create asymmetric edge hydrogenation, the ZBxNyCz ribbons were monohydrogenated (N–H) at one edge and dihydrogenated (C–H2) at the opposite edge, and the structure was subsequently labeled as H-ZBxNyCz-H2. On the basis of density functional theory and non-equilibrium Green’s function, our simulation revealed that H-ZBxNyCz-H2-based devices present a variety of abnormal spin-polarized transport properties. When the value of x and y in the H-ZBxNyCz-H2 structure is not equal (i.e., z is an odd number), the spin-polarized currents are restricted, regardless of their ferromagnetic (FM) or anti-ferromagnetic (AFM) state. When x is equal to y (i.e., z is an even number), the H-ZBxNyCz-H2 structure exhibits negative differential resistance and spin-filtering features in the FM state. Conversely, in the AFM state, the spin-polarized currents of the structure exhibit an exceptional oscillation effect with spin polarization as high as 100% at certain bias voltages. By adjusting the width of graphene and the spin states, the resulting hybridized H-ZBxNyCz-H2 structure can be potentially applied to the fabrication of spin nanodevices with exotic functionalities.