Density functional study of atomic and electronic structures of gold/black phosphorus interface

We study atomic and electronic structures of the gold/black phosphorus interface using density functional theory. To consider the experimentally observed corrugated interface of gold and black phosphorus, we place black phosphorus layers in contact with a corrugated gold surface and optimize positions of phosphorus atoms by minimizing the total energy of the system. For comparison we also consider an atomically flat interface. For each interface, we obtain the binding energy of gold and black phosphorus and analyze charge transfer between gold and black phosphorus, spatial distribution of electrons at the interface, and the projected density of states. We compare these properties of the two interfaces to find out the energetic stability of the corrugated gold/black phosphorus interface and the effect of the corrugation on the electronic structure of gold/black phosphorus interface.