Hexagonal-boron nitride/graphene van der Waals heterostructure-based wavelength-selective infrared absorbers using plasmonic metasurfaces for multi-spectral infrared photodetectors

Abstract

Graphene has promising applications for novel optoelectronic devices. However, graphene-based photodetectors have two major drawbacks that need attention. The first is how to preserve graphene’s original high carrier mobility, and the second is how to enhance graphene’s absorption to improve its performance. Hexagonal boron nitride (hBN)/graphene van der Waals (vdW) heterostructure-based plasmonic metasurfaces (PMs) are proposed for wavelength-selective infrared (IR) photodetectors. hBN preserves graphene’s high carrier mobility, and PMs enhance graphene’s absorption. Numerical calculations demonstrate sufficient wavelength-selective absorption in the broadband IR wavelength range. Such optical properties are realized by coupling the localized surface plasmon resonance (SPR) of PMs and propagating SPR of graphene. The proposed vdW heterostructure-based PMs could be used for high-performance multi-spectral IR photodetectors.