Extending Absorption Edge through the Hybrid Resonator-Based Absorber with Wideband and Near-Perfect Absorption in Visible Region

Abstract

Metamaterial absorber with the unexpected capability for harvesting electromagnetic energy has been regarded as a potential route for various applications, including chemical/biological sensing, cloaking and photovoltaic applications. In this study, we presented the simple absorber design made with Al/SiO2/Al sandwich structures through the involvement of hybrid dual-resonators that could allow the wideband light absorption covered from 450 nm to 600 nm with average absorptivity above 95%. Examinations of excited electric field, magnetic field and total magnitude of electric field in three-dimensional space at resonances were performed to clarify the origin of resonant behaviors. In addition, an equivalent inductance–capacitance circuit model was proposed that could qualitatively explore the geometry-dependent absorption characteristics by modulating the constitutive parameters of hybrid resonators. As a result, the designed light absorber might enable to be practically applied for various optical-management and photovoltaic applications, and even offered the tunability for other desired frequency regions.

Elliptical metallic rings-shaped fractal metamaterial absorber in the visible regime

“…To broaden the absorption spectrum, varieties of device configurations, including multilayer stacking of resonant elements in the vertical direction 41 , perpendicularly standing nanowires 42 and multiple resonators using in-plane arrangement 43 , have been used. Within the context, Lai et al .…”

“…Within the context, Lai et al . 43 used Al/SiO 2 /Al kind of sandwiched structures in a simple absorber with the integration of hybrid dual-resonators, and achieved polarization-insensitive absorption of above 95% in the 450–600 nm spectral range. Hoa et al .…”

“…However, complexities in structures introduce difficulties in manufacturing and applications. For example, the coalescing of multilayer absorbers with industrial technologies becomes challenging, owing to the bulky size, high manufacturing cost, and the use of noble metals 26 , 41 – 43 . In addition, though the use of multi-resonance approach remains simpler to fabricate the relevant device in comparison to the multilayer kind, the former method is still far behind the latter type owing to limited absorption in a specific frequency band 44 , 46 .…”

“…To broaden the absorption spectrum, varieties of device configurations, including multilayer stacking of resonant elements in the vertical direction 41 , perpendicularly standing nanowires 42 and multiple resonators using in-plane arrangement 43 , have been used. Within the context, Lai et al 43 used Al/SiO 2 /Al kind of sandwiched structures in a simple absorber with the integration of hybrid dual-resonators, and achieved polarizationinsensitive absorption of above 95% in the 450-600 nm spectral range. Hoa et al 41 reported ultra-broadband metamaterial absorber with high absorptivity (> 90%) in the visible and near-IR regimes (480-1,480 nm) by adopting symmetrical metasurfaces in a periodic arrangement of multilayered conical frustums.…”

A Wide Incident Angle, Ultrathin, Polarization-Insensitive Metamaterial Absorber for Optical Wavelength Applications

“…However, these may not be the only reasons for a nearperfect MMA. Perfect impedance match of the metal with the free space of the solar spectrum [37], [38], the plasmonic resonance characteristics of the dielectric layer [39], [40], a symmetrical structure resonator with good confinement of the EM wave [41], [42], and a good E-field, H-field and distributed surface charge are also reasons for high absorption [43], [44]. MMA may also consist of two-layer [45], fourlayer [46], [47], multilayer stacks [48]- [50] along with most common three-layer structure.…”