Numerical simulation of efficient solar absorbers and thermal emitters based on multilayer nanodisk arrays

• Published in: Applied thermal engineering Vol. 230; p. 120841
• Main Authors: Zheng, Ying, Yi, Zao, Liu, Li, Wu, Xianwen, Liu, Huan, Li, Gongfa, Zeng, Liangcai, Li, Hailiang, Wu, Pinghui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 25-07-2023
• Subjects: Angle insensitivity; High thermal emission efficiency; Multilayer film structure; Perfect absorption; Ultra-broadband absorption; Ultra-broadband absorption; High thermal emission efficiency; Angle insensitivity; Perfect absorption; Multilayer film structure
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2023.120841

Using the refractory metal TiN, we have designed an ultra-broadband perfectly absorbing solar absorber and an efficient thermal emitter. The multilayer nanodisc structure composed of TiN-Si3N4 obtained an average absorption efficiency of 91.5% in the wavelength range of 280–4000 nm, and the wavelength band with absorption efficiency greater than 90% reached 2929 nm. The weighted average absorption efficiency was 99%, lost solar energy is only 1%. The excellent absorption performance of the structure was confirmed. And we study the thermal radiation efficiency of the structure at different temperatures and obtain the optimal working temperature. We approximately consider that the optimal working temperature of the structure as a thermal emitter is 2000 K, and the thermal radiation efficiency at this temperature is 94.8%. It can be well applied to thermionic, thermal detection and other fields, and has application potential in the thermal emission field.
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•The absorber can achieve ultra-wideband efficient absorption in ultraviolet to near-infrared light.•The absorption efficiency of the absorber at AM1.5 is more than 99% and it has ultra-high thermal radiation efficiency.•The insensitivity of incident Angle and polarization Angle makes the absorber more widely used in the field of solar energy absorption.
In this work, we design a solar absorber and thermal emitter with ultra-broadband perfect absorption and high thermal radiation efficiency. The solar absorber has a high absorption efficiency of 91.5 % in the full wavelength range (280–4000 nm), and the weighted average absorption efficiency (AM1.5) is as high as 99 % by the finite difference time domain method (FDTD) simulation calculation. And the absorption bandwidth with absorption efficiency greater than 90 % reaches 2929 nm (280–3209 nm), and the average absorption efficiency in this band is as high as 97.4 %. Such strong absorption is due to the plasmon resonance and near-field coupling of the multilayer nanodisks. In addition to being used in solar absorbers, the structure also has potential applications in thermal emitters. The novelty of this work is to explore the application of the structure in the field of thermal radiation, and the optimal working temperature of the structure for thermal radiation is obtained. Through calculation, we approximately consider that the optimal working temperature of the structure as a thermal emitter is 2000 K, and the thermal radiation efficiency at this temperature is 94.8 %. The structure proposed by us is polarization-independent, insensitive to incident angle changes, the absorption spectra of transverse electric (TE) mode and transverse magnetic (TM) mode are the same, and the absorption efficiency remains 80 % even when the incident angle is increased to 60°. The excellent performance makes the structure widely used in the fields of solar energy absorption and emission.