Tunable wide-angle perfect absorber based on black phosphorous-dielectric-metallic hybrid architecture

Abstract

Black phosphorus (BP), as a newly emerging two-dimensional (2D) material, has received extensive interest due to its unique optical and electronic properties. In this work, we theoretically propose a monolayer BP-dielectric-metallic hybrid architecture, which exhibits a tunable nearly perfect absorption efficiency with ~99% at the mid-infrared wavelengths. The calculated results by finite-difference time domain (FDTD) simulations match well with the coupled-mode theory. The mechanism of the perfect absorption is due to the strong electromagnetic coupling between magnetic polaritons and BP surface plasmons as well as the guided mode. In addition, the hybrid system exhibits a strong tolerance for the absorption performance and remarkable property of polarization-sensitivity under wide incident angle range of 0°–60° attributable to the anisotropy of BP. The tunable characteristics can be achieved via changing the doping level of BP and the related geometrical parameters. These results suggest great potential applications in designing BP-based optoelectronic devices at the mid-infrared regime.