Abstract
A comparative study of different highly efficient broadband solar absorbers based on gold resonators is presented. We compare the absorption parameters for cylindrical, hollow cylindrical, pyramid, and sawtooth-shaped gold resonator structures over a wide input incident range at solar frequencies from 100 to 1200 THz (250 to 3000 nm). The performance of the structures is quantified in terms of the absorption, reflectance, and transmittance. We also numerically calculate the behavior of the structures when varying geometric parameters including the overall dimensions, the substrate size, and the resonator thickness. The proposed absorber structures can trap > 98% of the input incident light over a wide range of the terahertz (THz) spectrum. The performance of the absorber structures is compared based on their response to AM1.5 spectral irradiance to confirm their wide absorption behavior across the solar range. The proposed absorber structures offer higher absorption efficiency over a wide range of the solar spectrum. The effect of the height and other physical dimensions on the absorption is also presented. These results will help to choose the operating band for wide-angle and short-angle applications. This article also provides suggestions for the design of selective band absorption by changing the dimensions of such structures. The proposed absorber structures could be applied to design highly efficient solar cells with stable wide-angle behavior across input incident waves.