Graphene on plasmonic metamaterials for infrared detection

Abstract

Graphene consists of a single layer of carbon atoms with a two-dimensional hexagonal lattice structure. Recently, it has been the subject of increasing interest due to its excellent optoelectronic properties and interesting physics. Graphene is considered to be a promising material for use in optoelectronic devices due to its fast response and broadband capabilities. However, graphene absorbs only 2.3% of incident white light, which limits the performance of photodetectors based on it. One promising approach to enhance the optical absorption of graphene is the use of plasmonic resonance. The field of plasmonics has been receiving considerable attention from the viewpoint of both fundamental physics and practical applications, and graphene plasmonics has become one of the most interesting topics in optoelectronics. In the present study, we investigated the optical properties of graphene on a plasmonic metamaterial absorber (PMA). The PMA was based on a metal-insulator-metal structure, in which surface plasmon resonance was induced. The graphene was synthesized by chemical vapor deposition and transferred onto the PMA, and the reflectance of the PMA in the infrared (IR) region, with and without graphene, was compared. The presence of the graphene layer was found to lead to significantly enhanced absorption only at the main plasmon resonance wavelength. The localized plasmonic resonance induced by the PMA enhanced the absorption of graphene, which was attributed to the enhancement of the total absorption of the PMA with graphene. The results obtained in the present study are expected to lead to improvements in the performance of graphene-based IR detectors.