Perfect absorption of graphene sheets utilizing cavity-modulated resonant tunneling effect

In order to enhance the light absorption of graphene in the visible and near-infrared (NIR) ranges, the multilayer structure-based cavity-modulated resonant tunneling effect is introduced. Absorption characteristics of one configuration incorporates double layer graphene sheets are theoretically calculated and numerically simulated by transfer matrix method (TMM). The dependence of absorption intensity on structural parameters and incident angle are analyzed in detail. It is demonstrated that the resonant tunneling transmission cavity will be formed to strengthen the electric field intensity around the graphene, when graphene is embedded in a multilayer structure. Thus, the absorption can be significantly improved to 100%, which can also be controlled by varying the parameters of the structure. In particular, the design principle can be used for studying other two-dimension materials, and the proposed devices may be efficiently exploited as tunable and selective absorbers, photo-detectors and short-pulse lasers.