Numerical investigation of wideband L-shaped metasurface based solar absorber for visible and ultraviolet region

Abstract

A wideband metasurface absorber covering the visible to ultraviolet (UV) region (340 THz to 1150 THz) is numerically presented in this paper. The topmost layer consists of a periodic metallic array of L-shaped metasurface followed by a dielectric layer and thick metallic substrate. The nanostructure L-shaped metasurface array made up of tungsten material is used to enhance absorption spectra in the visible to the UV region. The average absorption resulted in an efficiency of 92.2% in the visible spectra (430 THz to 770 THz) and 73.6% absorption in the ultraviolet spectra (771 THz to 1150 THz). The absorption band has a close relationship with change in different parameters of the L-shaped metasurface absorber design is also investigated. The dual broadband achieves average absorption of more than 90% in visible region from 475 THz to 742 THz and in the ultraviolet region from 1010 THz to 1055 THz. The absorption is also investigated for inserted electromagnetic with different oblique incidence, which shows that the proposed absorber is achieving more than 80% absorption in-between 0° to 40° in the visible region from 470 THz to 750 THz. The presented broadband absorber is ultra-thin and single sized nanostructure can be used to scale large area photonics applications.