Broadband metasurface absorber achieving ultraviolet-to-mid-infrared efficiency for industrial solar thermal energy conversion

This work presents a novel broadband metasurface absorber engineered for high-efficiency solar energy harvesting across the ultraviolet, visible, near-infrared, and mid-infrared (0.20–3.00 µm) wavelength range. Comprehensive electromagnetic analysis using finite element method simulations demonstrates remarkable broadband absorption efficiency of 91% across the 0.20–3.00 μm wavelength range, spanning ultraviolet, visible, near-infrared, and mid-infrared regions. Peak absorption values reach 99.88% in the mid-infrared region, with strong angular tolerance up to 80° for both TE and TM polarizations. The design exhibits excellent polarization insensitivity and maintains high-performance under varying geometric parameters. Parametric optimization reveals optimal resonator thickness of 3.4 μm and circular diameter of 2.0 μm for maximum absorption efficiency. Machine learning analysis using polynomial regression models achieves perfect correlation (R² = 100%) between predicted and actual transmission spectra, validating the theoretical framework. Comparative analysis with existing literature demonstrates superior bandwidth (2800 nm) while maintaining competitive efficiency and angular tolerance. This work advances the field of solar thermal energy conversion by providing a scalable, high-performance absorber design suitable for industrial applications, district heating systems, and decentralized energy solutions. The current work is purely computational and theoretical, with no experimental validation conducted. Future work will focus on experimental realization and validation of the proposed design.