Bull's eye grating integrated with optical nanoantennas for plasmonic enhancement of graphene long-wave infrared photodetectors

Abstract

Two-dimensional (2D) materials have exhibited potential for infrared detection at room temperature, yet their low light absorption impedes their widespread application. In addition, micromechanical cleavage, which is the main method by which high-quality 2D layers are achieved, typically leads to small-area flakes, hampering their application as photodetectors. In this work, we designed a hybrid plasmonic structure, comprising a metallic bull's eye grating and optical nanoantennas, to collect and concentrate light into a piece of single-layer graphene with sub-wavelength lateral extent. This boosts the interaction between the graphene and light, thereby improving its photodetection performan..