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.

黑磷（BP）作为一种新兴的二维（2D）材料，由于其独特的光学和电子特性而受到广泛关注。在这项工作中，我们从理论上提出了一种单层BP-介电金属混合结构，该结构在中红外波长下具有约99％的可调近乎完美的吸收效率。有限差分时域（FDTD）模拟的计算结果与耦合模式理论非常吻合。完美吸收的机理归因于磁极化子与BP表面等离激元之间的强电磁耦合以及引导模式。此外，在BP的各向异性引起的0°至60°宽入射角范围内，该混合体系对吸收性能具有很强的耐受性，并具有出色的极化敏感性。可以通过改变BP的掺杂水平和相关的几何参数来实现可调谐特性。这些结果表明在中红外条件下设计基于BP的光电器件方面具有巨大的潜在应用前景。