Broadband and angle-insensitive metasurface solar absorber

We theoretically proposed and numerically analyzed angle insensitive and broadband I-shaped metasurface-based resonator placed above the dielectric layer to enhance absorption in the visible region. It is found that the absorber bandwidth is increased by using titanium (Ti) and gold (Au) material in the proposed design. To achieve wideband absorption of more than 95%, the dimension parameters of the structure are selected carefully in which the electromagnetic energy is maximum from 550 to 651THz. The perfect absorption is achieved from 550 to 651THz due to the coupling effect between the material used silicon dioxide (SiO2) and gold. The average absorption of 92.4% from 520 to 695 THz in the visible region. The bandwidth of 101 THz is achieved in which the proposed absorber showcases the more than 95% of absorption. In addition, the change in the absorption band is also presented with a change in different physical parameters such as the thickness of SiO2 and the top metasurface layer. The absorber with simple design and absorption remains the same for different oblique incidences from 0 degrees to 80 degrees resulting in proving that the proposed absorber is angle insensitive and can be easily fabricated. The effective impedance and electric field density are also presented in this paper. The proposed absorber can be applied in designing high absorption solar cell and have the potential in designing building block of photonics sensors in futuristic applications.