Solar Energy Harvesting Using Nickel-Based Superwideband Absorber With Nearly Perfect Blackbody Emission

Abstract

This article proposes the design of a superwideband absorber covering the infrared, visible light, and ultraviolet (UV) spectrum for solar energy harvesting application. It consists of nickel-based two concentric square rings. The absorber is made of a nickel ground plane, an intermediate substrate layer composed of polyimide dielectric material, and a nickel-based top resonating structure. The overall size of the absorber is $30\times 30\times 12~\text {nm}^{3}$ . It has an operating wavelength of 125.249–2007.657 nm (149.43–2395.23 THz) for absorption (A) $\geq 90$ % with an average absorption of 96.1%. The absorption remains at more than 95% in the wavelength range of 161.12–1582.58 nm (189.56–1873.6 THz). The absorber is insensitive to any change in polarization and also independent of the angle of the incident radiation, while having an average absorption of more than 90% till $\theta = 50^{\circ }$ and an average absorption of 85% is observed till $\theta = 60^{\circ }$ . The proposed absorber achieves 96.6% solar absorption efficiency and also achieves 95.14%, 96.17%, 96.51%, and 96.53% thermal emission efficiency at temperature 2000, 2500, 3000, and 3500 K, respectively. Thermal emissions are in good agreement with an ideal blackbody at all temperatures. Maximum $\eta _{\text {sol-thermal}}$ of 96.46% and maximum $\eta _{\text {sol-electrical}}$ of 67.2% are achieved for $C =1000$ at $T =500$ and 1000 K, respectively.