Tunable mid-infrared absorber based on graphene/ferroelectric stacks with dual-band selectivity

Abstract

Capabilities of multispectral absorbers are highly desirable for the advanced infrared system. Here, we report a room temperature tunable mid-infrared absorber with dual-band selectivity. Our device consists of a ferroelectric layer sandwiched between two single-layer graphene sheets. The artificially defined superdomain in the ferroelectric spacer, periodic ferroelectric domain array, offers a nonvolatile static electric field for doping of graphene with desired carrier-density patterns, making it possible for graphene plasmons excitation and propagation. The resonance frequencies can be simultaneously tuned in two bands of 4.5–11.9 µm and 5.2–20.7 µm by directly reconstructing the ferroelectric superdomain, and other two ranges of 5.8–17.8 µm and 6.7–19.4 µm by dynamically applying gate voltage. The demonstration of graphene plasmonic absorber tuned by ferroelectric superdomain opens up perspectives for fabrication of room temperature, reconfigurable multiband infrared devices.