Effects of short-range order and interfacial interactions on the electronic structure of two-dimensional antimony-arsenic alloys

The growth of two-dimensional (2D) antimony-arsenic alloys has been recently demonstrated using solid-source molecular beam epitaxy and this provides an additional degree of freedom to tailor their basic properties. With this perspective, we propose and conduct a comprehensive first principles investigation on this 2D group-V antimony arsenide (2D As_xSb_y), in both free-standing form as well as on common substrates of Ge(111), Si(111), bilayer graphene and bilayer hexagonal boron nitride (h-BN). Structural and electronic properties of the 2D As_xSb_y are evaluated for different compositions, different types of atomic arrangements for each composition, different lattice matched interfacial configurations of the composite heterostructures for the four substrates. These systematic studies provide property benchmarks for this new class of group-V 2D materials and reveal microscopic origins of the interfacial interactions, orbital hybridization, charge transfer and the resulting electronic structures of the 2D alloy.