High-efficiency graphene-based metasurface absorber with T-shaped resonators for broadband solar energy harvesting in renewable energy applications

This study proposes a graphene-based metasurface absorber incorporating T-shaped and circular ring resonators, coated with ferric oxide (Fe₂O₃) and tungsten, respectively, and fabricated on a silicon dioxide substrate. The design achieves remarkable broadband absorption, averaging 97.04 % from the ultraviolet to the mid-infrared spectrum, with peak performance in the visible range reaching 99.46 %. Numerical simulations show that the absorber sustains high efficiency across a wide range of incident angles, with transverse magnetic (TM) polarization exhibiting greater angular stability than transverse electric (TE) mode. Parametric optimization varying graphene chemical potential (0.1–0.9 eV), resonator height (0.4–3.6 μm), and T-shaped resonator length (0.35–1.25 μm) demonstrates the structure’s tunable optical response. Electric field distribution analyses reveal strong light–matter interactions concentrated at resonator interfaces, particularly at longer wavelengths. Furthermore, Bayesian regression modeling confirms the design’s predictable behavior, yielding R² values exceeding 95 % under different incidence angles and geometric configurations. These results present an advanced solar absorber with strong potential for applications in photovoltaic thermal systems, thermos photovoltaics, and solar thermochemical energy conversion.