Engineering intrinsically low Schottky barrier via spin-driven band alignment in Janus SMnSe/graphene heterostructure

Janus antiferromagnetic systems intrinsically exhibit spin splitting in the absence of net magnetization due to their atomic asymmetry, and hence offer exciting prospects for various spintronics applications. Here, we employ density functional theory calculations to investigate the electronic properties of Janus SMnSe and its heterostructure with graphene. The broken inversion symmetry introduced by the non-symmetrical chalcogenide environment around Mn atoms leads to pronounced spin splitting even in the absence of spin–orbit coupling. Exploiting this spin-polarized nature, we further explore SMnSe as a channel material interfaced with a graphene electrode. The SMnSe/graphene interface effectively reduces band bending by lowering the work function, thereby facilitating carrier injection. Our findings demonstrate that spin splitting in Janus SMnSe, induced by atomic asymmetry, can be harnessed to design intrinsically low Schottky-barrier based current-in-plane devices, with barrier height tunable via interlayer distance modulation.