Anisotropic infrared plasmonic broadband absorber based on graphene-black phosphorus multilayers

Two-dimensional materials (2DMs) such as graphene and black phosphorus (BP) have aroused considerable attentions in the past few years. Engineering and enhancing their light-matter interaction is possible due to their support for localized surface plasmon resonances in the infrared regime. In this paper, we have proposed an infrared broadband absorber consisting of multilayer graphene-BP nanoparticles sandwiched between dielectric layers. Benefiting from the properties of graphene and BP, the absorber exhibits both perfect broadband responses and strong anisotropy beyond individual graphene and BP layers. The absorber is tunable with the variation of geometric parameters as well as the doping levels of graphene and BP. The physical insight is revealed by electric field distributions. Furthermore, the angular robustness for incident wave is investigated. The proposed anisotropic omnidirectional broadband absorber may have promising potential applications in various biosensing, communication and imaging systems. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement