Graphene-Based Cross-Shaped Surface Plasmon Resonance Solar Absorber Design for Solar Thermal Energy Converters

In this demonstrated design, we built a perfect solar absorber, with three appropriate layers of base (tungsten) layer, substrate (aluminum), layer, and gold resonator in a cross-design. The absorption result of the demonstrated cross-design can be identified in three sections by dividing the whole wavelength range (2800 nm) into two sections the first 1400-nm bandwidth range (starting from 0.2 to 1.6 µm), and the second part of 1400 nm (between 1.6 and 3 µm) respectively. With the support of the adding graphene layer by developing the top and middle layer, the absorption percentage can be increased to 91% for the overall range of 0.2 and 3 µm. The developed cross-design absorption rate is above 90% at an overall bandwidth of 2800 nm. For the first half section of the 1400-nm bandwidth (0.2–1.6 µm), the absorption amount is observed more than 90%, and at the rest half of the overall wavelength (1.6–3 µm), the solar radiation is greater than 95%. To highlight the variation in absorption situations, the peak four wavelengths (micrometers) are picked up such as λ 1 = 0.33, λ 2 = 1.23, λ 3 = 2.24, and λ 4 = 2.6 respectively. In this developed cross-solar design, the absorber can be explored in the four spectra of ultraviolet (UV) region, violet (V), and near and middle infrared regions (NIR and MIR). The creation of the cross-design in many steps, and it can be also expressed with the AM 1.5 situation. To indicate the absorption value variations for this cross design, various parameter sections of the ground layer parameter, cross design length, and substrate length can be distinguished in four different peak wavelengths. The electric potential value changes and the color distinguished of the electric field progression of the cross-design can be also extinguished. Transverse electric value and magnetic (TE and TM) variations in four different peak wavelengths can be demonstrated by varying degrees from 0 to 50. Finally, the proposed cross-design absorption value can be compared with the other published design in a table with the respective sections of absorption percentage, bandwidth range, angle variation, and polarization sensitivity respectively.