Surface plasmon resonances between silver nanoribbons and anisotropic black phosphorus to light confinement

Abstract

Two-dimensional plasmonic materials generally use patterned structural design to enhance the intensity of interaction with light near the resonance wavelength. We propose a non-patterned monolayer black phosphorus (BP) and patterned silver periodic nanostructures. The surface plasmon resonances (SPRs) between the upper metal silver nanoribbons or silver nano-square matrix and the BP sheet are used to achieve effective light confinement. Since the BP sheet is continuous in the structural design, the absorption response of the system can be dynamically adjusted by voltage-controlled Fermi level of BP. We also discussed two structural parameters closely related to the local size of SPR, the width of silver nanoribbons w 1, and the distance d 1 between silver and BP. The crystal structure of the BP puckered shows a strong in-plane anisotropy. When the silver in the system is a nanoribbon and a nano-square matrix, we research the anisotropy of the system by placing the BP in different directions relative to the structure and change the polarization angle of the incident light. The proposed anisotropic structure has the ability to achieve light confinement, which provides the basis for the construction of plasmonic sensors and polarization switches.