Enhanced absorption based on gap-plasmon resonance and Fabry–Perot resonance in a refractory metasurface

Abstract

In this paper, we report a polarization-independent broadband metasurface perfect absorber based on tunable gap magnetic resonance and Fabry–Perot (FP) resonance in a structure with consecutive size variation. By using the finite-difference time-domain method, the effects of size parameters are investigated. Due to the coexistence of the FP-like resonance and gap magnetic resonance, the near-unit absorption reaches as high as 99.46% with nanocone morphology throughout the visible-to-near infrared regime where most solar radiation is located. The structure raised in this paper is less complex and more thermally stable due to abandoning the spacer layer in traditional tri-layer structures. This method can be developed for other refractory materials and has great potential in solar energy related optoelectronics applications.

Broadband Absorption Based on Thin Refractory Titanium Nitride Patterned Film Metasurface

“…Various MPAs based on TiN achieve near-perfect absorption based on morphologies such as square, disk, cone or truncated-cone, tapered multilayer stacks, nanopillar, etc. [20,[27][28][29][30][31][32] While some of the metasurface designs are difficult to fabricate including many layers or complicated morphology, others cannot achieve perfect absorption bandwidth.…”