Realization of robust Ohmic contact for semiconducting black arsenic by coupling with graphene

Ohmic contacts are fundamental components in semiconductor technology, facilitating efficient electrical connection and excellent device performance. We employ first-principles calculations to show that semimetallic graphene is a natural Ohmic contact partner of monolayer semiconducting black arsenic (BAs), for which the top of the valence band is below the Fermi energy of the order of 10² meV. The Ohmic contact arises from the giant Stark effect induced by van der Waals electron transfer from BAs to graphene, which does not destroy their respective band features. Remarkably, we show that this intrinsic Ohmic contact remains robust across a wide range of interlayer distances (adjustable by strain) or vertical electric fields, whereas the weak spin splitting of the order of 1 meV induced by symmetry breaking plays little part in Ohmic contact. These findings reveal the potential applications of graphene–BAs in ultralow dissipation transistors.