Sizable bandgaps of graphene in 3d transition metal intercalated defective graphene/WSe(2) heterostructures

Controlling the electronic and magnetic properties of G/TMD (graphene on transition metal dichalcogenide) heterostructures is essential to develop electronic devices. Despite extensive studies in perfecting G/TMDs, most products have various defects due to the limitations of the fabrication techniques, and research investigating the performances of defective G/TMDs is scarce. Here, we conduct a comprehensive study of the effects of 3d transition metal (TM = Sc–Ni) atom-intercalated G/WSe(2) heterostructures, as well as their defective configurations having single vacancies on graphene or WSe(2) sublayers. Interestingly, Ni-intercalated G/WSe(2) exhibits a small band gap of 0.06 eV, a typical characteristic of nonmagnetic semiconductors. With the presence of one single vacancy in graphene, nonmagnetic (or ferromagnetic) semiconductors with sizable band gaps, 0.10–0.51 eV, can be achieved by intercalating Ti, Cr, Fe and Ni atoms into the heterostructures. Moreover, V and Mn doped non-defective and Sc, V, Co doped defective G/WSe(2) can lead to sizable half metallic band gaps of 0.1–0.58 eV. Further analysis indicates that the significant electron transfer from TM atoms to graphene accounts for the opening of a large band gap. Our results provide theoretical guidance to future applications of G/TMD based heterostructures in (spin) electronic devices.