hBN-Encapsulated Graphene Coupled to a Plasmonic Metasurface via 1D Electrodes for Photodetection Applications

Abstract

It is shown here how encapsulated graphene devices can be laterally coupled to plasmonic metasurfaces via 1D edge contacts, preserving the high mobility of encapsulated graphene while enhancing optical coupling. The device is used for photodetection applications where high responsivities in the range of 100 A W⁻¹ for most of the visible spectrum are reported. The device exhibits a photogating effect which is attributed to defect states in the encapsulating hBN layers. The results highlight a new configuration to couple graphene with plasmonic structures and points to a new type of device based on defect states and graphene's excellent transport properties to achieve photodetectors with ultrahigh responsivities.