摘要
As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorption bandwidth while ensuring high absorption efficiency. In this work, we proposed a hybrid nanostructure, which not only can improve absorption efficiency but also can increase absorption bandwidth. The proposed hybrid nanostructure consists of a monolayer graphene sandwiched between three Ag gratings with different widths and a SiO2 spacer on a Ag substrate, these three gratings and substrate can excite three independent magnetic dipole resonances. In our calculations, we numerically demonstrate the proposed hybrid structure can achieve graphene absorption bandwidth of 0.311 μm in near-infrared region with absorption exceeding 30%. We also studied absorption peaks dependence on gratings widths and SiO2 spacer thickness, and explained the results using physical mechanism. Our research can provide a theoretical guidance for future device preparation.
As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorption bandwidth while ensuring high absorption efficiency. In this work, we proposed a hybrid nanostructure, which not only can improve absorption efficiency but also can increase absorption bandwidth. The proposed hybrid nanostructure consists of a monolayer graphene sandwiched between three Ag gratings with different widths and a SiO2 spacer on a Ag substrate, these three gratings and substrate can excite three independent magnetic dipole resonances. In our calculations, we numerically demonstrate the proposed hybrid structure can achieve graphene absorption bandwidth of 0.311 μm in near-infrared region with absorption exceeding 30%. We also studied absorption peaks dependence on gratings widths and SiO2 spacer thickness, and explained the results using physical mechanism. Our research can provide a theoretical guidance for future device preparation.
