Simulated Performance of a Broadband Solar Absorber Composed of Sectioned Au Disk Structures and ZnS/Au Thin Layers

Abstract

Solar energy is considered an essential source of energy because of cleanliness and ubiquity. However, how to effectively absorb solar energy within the range of solar radiation is an urgent problem to be solved. The design of high-performance broadband perfect absorbers is an important way to collect solar energy efficiently. In this paper, we propose a novel broadband solar energy absorber based on zinc sulfide (ZnS). It is a three-layer (Au-ZnS-Au) structure with new types of sectioned disks employed in the top layer. The sectioned disks can enhance the absorption efficiency. Surface plasmon polariton (SPP) and electric dipole resonance increase the absorption of light, so the proposed absorber can achieve broadband perfect absorption. Simulation by a finite element analysis (COMSOL) method shows that absorption with a bandwidth of 354 THz from 430 THz–784 THz has been achieved, and the average absorption is 95%. This indicates that the perfect absorption range of the proposed absorber is 78.7% of the visible range. The perfect absorber has four perfect absorption peaks, which can reach a maximum absorption rate of 99.9%. In addition, our absorber is polarization insensitive due to the design of the rotational symmetry structure of the sectioned disks. The absorber is composed of refractory metals so that it can work under actual solar radiation and high-temperature conditions. The proposed solar energy absorber is important for many applications such as solar cells, thermal photovoltaic technology, and sensing.