Strong and Broadband Visible Absorption Based on Titanium Patterned Resonator

The visible band is characterized by a high concentration of solar energy, making it highly desirable to achieve perfect absorption within this spectral range. This paper presents a novel design of a broadband metamaterial absorber (BMA) based on titanium (Ti), which exhibits a superior level of high absorption in the visible regime. The absorber is composed of three layers arranged from top to bottom: a newly shaped Ti top layer resonator, a SiO2 dielectric spacer, and a Ti bottom reflector. With a thickness of 195 nm, the BMA structure demonstrates an average absorption of 98.11% across the wavelength range of 400-800 nm, ensuring absorption levels greater than 90% through the entire visible band. The influence of different geometrical parameters and structures on absorption was studied, and the physical mechanism behind the high absorption was explored. Additionally, the proposed structure offers the benefit of maintaining 90% absorption stability for large incident angles up to 60 & DEG; for TE and up to 70 & DEG; for TM mode oblique incidence. Therefore, our proposed absorber emerges as an optimal candidate for a variety of solar energy harvesting applications.