Broadband visible-light absorber via hybridization of propagating surface plasmon

Abstract

We demonstrate a broadband visible-light absorber based on excitation of multiple propagating surface plasmon (PSP) resonances. The simple structure is constructed of continuous gold/silica multi-layers covered by a one-dimensional gold grating. The broadening of bandwidth arises from the inter-layer hybridization and spectral superposition of PSPs, which is predicted with the analytical coupled oscillator model and validated using the RCWA simulation. The average absorption increases with the number of gold/silica pairs and exceeds 95% over the whole visible spectrum when only five pairs are included. Moreover, results show that the absorption can be further enhanced by grading the thickness of silica layers. The presented design might enable promising applications in the fields of photovoltaic cells and thermal emitters, owing to its advantages of wideband, near-unity absorption and simple fabrication simultaneously.

Wide-Angle Polarization-Independent Ultra-Broadband Absorber from Visible to Infrared

“…The designed absorber was constructed based on localized surface plasmon resonance (LSPR) by using a multi-layer nanostructured thin layer. However, we would show that the designed absorbers offered better absorption effect (wider bandwidth) than all previously reported broadband absorbers operating in a spectrum from visible light to middle-infrared [10][11][12][13][14][15][16][17][18][19][20][21]. The proposed ultra-broadband absorber could achieve a nearly perfect absorption covering a broad range, the absorption peak was 99.99%, the average absorption rate was 97.2% from visible light to middle-infrared light (i.e., from 400 to 6000 nm), and an absorption bandwidth over 5400 nm (>90%).We would first prove that the structure is advantageous for impedance matching with free space as compared with the reported conventional planar-film structures, which extremely impacts on generating an ultra-broadband perfect absorption.…”

“…An alternative structure to broaden the absorption bandwidth is to design a metasurface, which stacks the multi-layer dielectric and metal with different areas and different morphologies on a metallic substrate. In the past, Cong et al used one-dimensional multilayered Au/SiO 2 films via hybridization of propagating surface plasmon to design a broadband visible-light absorber, and the average absorption over the visible band of 400-750 nm could reach only nearly 90% [17]. Zhong et al proposed a configuration of polarization-selective metamaterial perfect absorber with ultra-wide absorption bandwidth [18].…”

Engineering Light at the Nanoscale: Structural Color Filters and Broadband Perfect Absorbers

“…The additionally incorporated resonators provide flexibility in selecting absorption frequency range and can achieve even broader absorption, but also require more complicated fabrications . Novel structures featuring broadband impedance matching without exciting resonances have been recently proposed accompanied with various cost‐effective fabrication methods, thereby opening up a new path to the extensive use of broadband absorbers in various applications …”

Ultrathin Six-Band Polarization-Insensitive Terahertz Perfect Metamaterial Absorber Based on a Cross-Cave Patch Resonator

“…PMMAs have recently been developed rapidly in a wide electromagnetic (EM) spectrum range from microwave [1][2][3], terahertz [4][5][6][7][8][9][10][11], infrared [12][13][14][15][16], to visible region [17][18][19][20]. PMMA is not limited by the quarter-wavelength thickness and also scaled to different EM spectrum due to its geometry scalability.…”