Numerical investigation of gold metasurface based broadband near-infrared and near-visible solar absorber

We present broadband solar absorber using gold metasurface resonators. The gold metasurface resonators are placed above MgF₂ substrate and tungsten ground plane. MgF₂ substrate is widely used substrate in solar absorber for achieving higher absorption. The ground plane made of tungsten material reduces the overall cost of the structure. The results are presented in the form of reflectance, transmittance, absorptance, electrical field energy, and magnetic current density. The results are presented in the frequency range of 300 THz to 500 THz. The absorber is given higher absorption in the whole frequency range. Gold resonators play a vital role in trapping light into the substrate layer. The design results are optimized by observing the response for different physical parameters like length of gold resonators, height of gold resonators, height of MgF₂ substrate, and height of tungsten layer. The results clearly show the shift in the spectrum by varying the different physical parameters of the design. The proposed solar absorber can become a building block of several photovoltaic devices applicable to energy harvesting.