Graphene-Silver Hybrid Metamaterial for Tunable and High Absorption at Mid-Infrared Waveband

We proposed a hybrid metamaterial structure based on graphene-silver, which has tunable and efficient light-absorbing performance at the mid-infrared regime. It is shown that this model can absorb light effectively with a maximum of 100% at the absorption peak wavelength. In addition, the absorption peak wavelength can be adjusted flexibly by changing parameters, including the chemical potential applied to graphene or other structural parameters of the structure. This nearly perfect absorption capability is attributed to the synergetic effects of the localized surface plasmon enhancement of Ag nanoribbon, graphene plasmonics, metal-insulator-graphene mode and Fabry-Perot resonance. This kind of tunable absorber can be used in mid-infrared photodetectors or spectroscopy fields.