Anisotropy of the quasiparticle electronic structure and excitons of pentacene:black phosphorus interfaces

Black phosphorus (BP) is a layered material that has emerged as a promising 2D semiconductor with anisotropic properties.  In this work, we study interfaces formed by a monolayer of pentacene adsorbed on monolayer BP by placing the pentacene monolayer along the zigzag and armchair directions of the BP substrate, respectively. We performed first-principles GW plus Bethe–Salpeter equation (GW-BSE) calculations to determine the quasiparticle band structure and excitons of the pentacene:BP interfaces in both orientations. We focus on the anisotropy of the interactions between the monolayer pentacene and BP, and discuss how the anisotropy of BP modulates the interfacial quasiparticle electronic structure and optical properties, as well as how the adsorption of the pentacene monolayer modulates the anisotropy of BP properties. Our results shine light on the understanding of the BP surface passivation via molecular adsorption and provide benchmark results for future experimental and computational studies.