Design of a triple-band black phosphorus-based perfect absorber and full-wave analysis using the semi-analytical method of lines

Abstract

A novel triple-band perfect plasmonic absorber that operates in the infrared regime was designed in this study. This absorber has a periodic multilayered black phosphorus (BP)/dielectric structure mounted on an Ag mirror with three distinct absorption peaks located at 6.44 µm, 10.09 µm, and 17.46 µm, and with near perfect absorption efficiencies of 96.72%, 97.17%, and 95.62%, respectively. The absorption performance of the designed structure can be tuned independently for each of the resonance bands by controlling the corresponding Fermi level of the BP-nanoribbons. Moreover, we demonstrated that the operation of the proposed absorber is independent of the incident angles in the angular range from normal to ± 50°. The semi-analytical method of lines was extended to conduct full-wave analysis of the proposed absorber. The semi-analytical nature of this method greatly reduces the computational time required and memory consumption compared with fully numerical methods. Direct comparisons with the results obtained by using the finite difference time domain method demonstrated their full consistency.