Electric Field Induced Spin Resolved Graphene P-n Junctions On Magnetic Janus VSeTe Monolayer

Graphene-based p-n junctions exhibit intriguing and distinctive electronic properties,making them promising candidates for spintronic and spin-photonic devices.While the attendant realization of magnetized graphene p-n junctions is highly desirable.Using first-principles calculations,we show that in the presence of magnetic proximity coupling effect of graphene supported on Te-termination magnetic Janus VSeTe monolayer G/Te@VSeTe,graphene is readily spin-polarized and the Dirac bands keep intact.More interestingly,in this system the bands of the spin down channel near Fermi level are quite sensitive to the external electric field(E_ex)due to the dominant electronic Coulomb screening effect.Thus,it can be modulated to spin resolved n type doping from initial p type when the E_exis opposite to intrinsic dipole moment of VSeTe and exceeds 0.35e V/?.However,those of the spin down channel in the vicinity of Fermi level are inert and still preserves initial p type against the external electric field.In terms of such distinctive differences between the Dirac bands in spin up and spin down channels,we propose a featured spin resolved graphene p-n junctions on magnetic Janus VSeTe by applying appropriate external electric field.Our findings can not be reproduced in G/Te@VSeTe heterostructure,where the intrinsic dipole moment is opposite to the direction of G/Te@VSeTe.We also check whether our proposed mechanism is available or not in other magnetic Janus heterostructure constructed with graphene,one is Cr Br S and the other is Fe ICl.Janus Cr Br S has magnetism,but has no intrinsic dipole moment.Although the band properties of G/Cr Br S are similar to the case of G/Te@VSeTe,it can also not be reproduced the transition from initial p type to n type due to the initial heavy p doping.However,in G/I@Fe ICl system with both magnetism and intrinsic dipole moment,we find that when the external electric field exceeds-0.30 e V/?,both the Dirac points of the spin channels move down to the Fermi level.This again confirms that initial p doping of graphene transforms to n type doping in G/I@Fe ICl by external electric field,and consequently,can be further constructed spin resolved graphene p-n junction.This significantly means that our proposed mechanism is generally applicable to other magnetic Janus heterostructure combined with graphene,and might provide a feasible strategy to realize stable spin resolved graphene p-n junctions extendedly.