Solar thermal application and optimization of a staircase-shaped resonator broadband solar absorber

Abstract

The development of efficient energy absorbers is essential for optimizing solar energy utilization, particularly for applications such as thermophotovoltaics and other solar energy harvesting technologies. Current research typically focuses on improving the efficiency of the solar absorbers with low-cost materials. This study addresses this limitation by introducing a broadband solar absorber with a staircase-shaped resonator structure. The absorber employs tungsten as the substrate due to its high thermal conductivity and stability, with a GaInAsP layer forming the staircase resonator. Simulations using finite element methods demonstrate that the proposed two-layered structure achieves over 90% absorption within the 200–3000 nm wavelength range, including ultraviolet and visible spectra. This broad absorption range maximizes solar energy capture and conversion efficiency. A parametric examination demonstrates how geometric factors like substrate depth and resonator dimensions affect the absorption effectiveness. The unique staircase shape of the resonator enhances light trapping and absorption across the full spectrum. Under real-world conditions, the absorber effectively captures solar energy across various angles and polarizations. These findings contribute to the advancement of energy absorber design and offer insights for future innovations in solar energy harvesting.