Graphene-based wideband metamaterial absorber for solar cells application

A wideband metamaterial (MTM) absorber based on a concentric ring resonator is discussed at visible frequencies. The proposed structure offers a wideband absorption response, where absorption of >70% is gained for the frequency ranging from 537.91 to 635.73 THz. The analysis is conducted on the components of the proposed structure to understand the origin of wideband absorption. Furthermore, a graphene monolayer sheet is integrated to the proposed MTM absorber to optimize its absorptivity, where the studies show enhancement of the absorptivity of the proposed structure up to 26% from its initial absorptivity. MTM absorbers of this kind have potential applications in solar cells. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE

Enhanced Mid -Infrared Reflectance with Graphene Coated Silicon Carbide Nanowires

© 2020 IEEE. The mid-infrared optical spectrum hosts a variety of promising photonic applications. Herein we simulate and experimentally demonstrate reflectance enhancement of MIR light using graphene-coated silicon carbide nanowires on silicon, showing promise for on-chip MIR Nano photonics

Enhanced absorption with graphene-coated silicon carbide nanowires for mid-infrared nanophotonics

The mid-infrared (MIR) is an exciting spectral range that also hosts useful molecular vi-brational fingerprints. There is a growing interest in nanophotonics operating in this spectral range, and recent advances in plasmonic research are aimed at enhancing MIR infrared nanophotonics. In particular, the design of hybrid plasmonic metasurfaces has emerged as a promising route to realize novel MIR applications. Here we demonstrate a hybrid nanostructure combining graphene and silicon carbide to extend the spectral phonon response of silicon carbide and enable absorption and field enhancement of the MIR photon via the excitation and hybridization of surface plasmon po-laritons and surface phonon polaritons. We combine experimental methods and finite element sim-ulations to demonstrate enhanced absorption of MIR photons and the broadening of the spectral resonance of graphene-coated silicon carbide nanowires. We also indicate subwavelength confinement of the MIR photons within a thin oxide layer a few nanometers thick, sandwiched between the graphene and silicon carbide. This intermediate shell layer is characteristically obtained using our graphitization approach and acts as a coupling medium between the core and outer shell of the nanowires

Polarisation insensitive tunable metamaterial perfect absorber for solar cells applications

Developing a perfect absorber based on metamaterials (MTMs) is a promising technique towards improving the efficiency of solar photovoltaic cells. In this study, a novel MTM-based perfect absorber (MPA) is proposed for solar cell applications, which exhibits an excellent single-band with high absorption rate of 99.7% in visible frequency regime (resonance frequency of 614.4 THz) with an outstanding absorption bandwidth of 15.5%. The proposed design presents a high symmetry flexibility which makes it easy to fabricate. Besides, the simulation results for the defined different incident angles and different polarisation (transverse electric and transverse magnetic) confirm the quality of the proposed design by showing how insensitive it is to both the defined incident angles (normal and oblique incident) and different polarisation angles of electromagnetic wave. The parametric study on dielectric spacer shows the tunability characteristic of an intended MPA structure. The proposed MPA design is a good candidate for fabrication of high-efficiency solar cell operating in a visible frequency range

Design and characterization of a dual-band perfect metamaterial absorber for solar cell applications

This paper proposes a metamaterial absorber design for solar energy harvesting using a simplified and symmetric structure. A unit cell of this design consists of three important layers namely, the bottom metallic layer, which is gold lossy, the intermediate layer: made of a lossy dielectric material that is gallium arsenide and patches which formed by a combination of gold and gallium arsenide. These three important layers are being carefully arranged at the top of a dielectric spacer. The geometric structure was being examined for its contribution towards absorption characteristics. The simulation results show outstanding dual-bands absorption (99.96% and 99.37%) in the visible frequency regime of electromagnetic wave. Due to the excellent symmetric nature of the proposed structure, its absorptance capacity exhibits polarization insensitivity for a wide range of incident angles for electromagnetic radiation

Theoretical and thermal characterization of a wideband perfect absorber for application in solar cells

This paper suggests a metamaterial (MTM) absorber structure to be used for efficiency improved solar cell. The proposed MTM absorber consists of the topmost three concentric circular ring resonators, and a ground metal plane sandwiched to the top layer with a dielectric spacer. Numerical simulation and theoretical (interference theory) studies on the proposed design show a wideband with near-perfect (>99%) absorption response in the visible frequency region of the solar spectrum. Thermal characterization of the suggested design is also conducted in order to investigate its absorption capability at different temperatures. The proposed MTM absorber design is believed to be an outstanding candidate toward high-efficiency solar photovoltaic cell

Wide-band polarization independent perfect metamaterial absorber based on concentric rings topology for solar cells application

Since the discovery of metamaterial absorber to the present days, several designs were proposed which display single-, dual-, and multiple-bands absorption responses in almost all regions of solar spectrum. However, little work has been done for wide-band metamaterial absorber in the visible frequency range. Hence, a novel wide-band metamaterial perfect absorber (MPA) based on concentric Circular Ring Resonator (CRR) topology is proposed for the application to improve the absorbance of solar photovoltaic cells for the visible frequency region. The proposed design consists of three basic components as resonators, ground metal, and dielectric spacer. The geometrical parametric study is conducted in order to investigate the flexibility of the proposed MPA structure. The design flexibility also analyzed by the polarization angle insensitivity character, in which the proposed design provides the perfect absorption for different angles of the incident electromagnetic wave as well as for TE and TM polarized waves