Design of a broadband infrared absorber based on multiple layers of black phosphorus nanoribbons

A polarization-sensitive broadband plasmonic absorber consists of multiple black phosphorus (BP)/dielectric layers stacking on an Ag reflector has been proposed theoretically and demonstrated numerically for infrared (IR) regime. The optimum geometrical parameters have been achieved by parametric sweep analyses with regard to the fabrication considerations and miniaturization of the absorber structure. So a high absorption (above 85%) with relatively broad bandwidth of 5.24 µm corresponding to the relative bandwidth of 42.12% has been achieved for the designed periodic structure with optimum unit cell dimensions of 0.5 µ m × 1.755 µ m . The electromagnetic loss in the BP material is the foundation of absorption performance in the designed absorber. The proposed anisotropic broadband IR absorber may have great potential in many areas of photonics.