Spin-polarized current in wide bandgap hexagonal boron nitrides containing 4|8 line defects

Abstract

Line defects (LDs) which are commonly present in two-dimensional materials play an important role in spintronic applications for generating and transporting spin current. We theoretically predict of the electronic and magnetic properties of n-type doped monolayers of hexagonal boron nitride (h-BN) with 4|8 LDs. The LDs can create two deep narrow bands in the band gap of the h-BN sheet with an energy separation about 2.75 eV at Γ point. Interestingly, at a certain concentration of electrons introduced by n-type doping, a tantalizing spontaneous one-dimensional ferromagnetic ordering emerges due to the partially-occupied narrow conduction band. Moreover, it is found that this electron doping induced spin polarization (of charge current) is up to 90% in the bias voltage range from 0.1 V to 0.4 V. Our findings indicate that the h-BN monolayer can functionalize a semiconductor for spintronic devices applications, which is beyond a common sense of h-BN tunneling barrier.