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

It is shown here how encapsulated graphene devices can be laterally coupled toplasmonic metasurfaces via 1D edge contacts, preserving the high mobility ofencapsulated graphene while enhancing optical coupling. The device is used forphotodetection applications where high responsivities in the range of 100 A W1for most of the visible spectrum are reported. The device exhibits a photogatingeffect which is attributed to defect states in the encapsulating hBN layers. Theresults highlight a new configuration to couple graphene with plasmonic structuresand points to a new type of device based on defect states and graphene’s excellenttransport properties to achieve photodetectors with ultrahigh responsivities.