Metamaterial-based square ring–hourglass resonator for broadband and polarization-independent graphene solar absorption with machine-learning-assisted optimization for renewable mining applications

Solar absorbers are promising technologies for renewable energy harvesting due to their simple and practical implementation. Their absorption performance strongly depends on the constituent materials and the geometry of the resonant structures, which can be tailored to achieve enhanced and broadband absorption. The current work is developed as a Square Ring with Hourglass Resonator Broadband Absorber (SRHRBA) structure, and the total performance is 93.63% for overall absorption at 2800 nm. With the graphene layer, it achieves more than 97% within 1000 nm, and the absorption under the AM 1.5 situation explored 96.4%. The geometry designs for lithography, the resonance development, the parametric ‘nm’ analysis, and the Random Forest model under the ML section, used with a 0.25 test size, are included in the current SRHRBA work. The incidence angles of 0 – 80-degree variation are included to show the polarization–independent development and the comparison with the related references also presented. With perfect absorption, the current SRHRBA can be used for thermal conversion involving domestic hot water, pool and space heating, industrial process heating, and photothermal catalysis.