An ultra-high sensitivity surface plasmon resonance sensor based on graphene-aluminum-graphene sandwich-like structure

An ultra-high sensitivity graphene optical sensor based on the surface plasmon resonance (SPR) is proposed using the graphene-aluminum (Al)-graphene sandwich-like structure. Here, the graphene sheets are introduced for enhancing the SPR and preventing the oxidation. It is found that our proposed graphene optical sensor is 3.4 times more sensitive than the Al-based sensor without the graphene layers. We demonstrate that a higher sensitivity can be obtained at the short wavelength due to the increases of the sensitivity with the decreases of wavelength. Especially, the sensitivity can be enhanced marked by increasing the number of graphene layers, which is totally different from the previous graphene-based optical sensor where the sensitivity is often decreased with the increases of the number of graphene layers.