Designed Graphane-based spin filters by tuning the sp2/sp3 configuration

Abstract

The electronic transport properties of H-vacancy-defected graphane are investigated by using the density functional theory (DFT) and Non-equilibrium Green’s Function (NEGF) methods. Results show that the band gap of graphane depends on the relative positions of the defect bands introduced by H vacancies and the valence or conduction bands, suggesting the band gap controllability. The defect bands are obviously spin polarized and the ratio is almost 100%. And the magnetization of the system can be tuned by defect concentration and location. Moreover, in the two-probe systems, the presence of H-vacancy-defect bands near the Ef plays an important role in controlling spin-dependent transport of graphane. A perfect spin-filtering effect with 100% spin polarization could be realized by H-vacancy defects. The spin properties indicate the potential of graphane as an option for future graphene-based spin filters and spintronic devices.