Inverse-designed MXene metamaterial absorber for broadband solar energy harvesting

Solar energy is widely applied in fields such as photovoltaic technology, seawater desalination, and photodetection, where efficient utilization of solar energy has been a long-standing pursuit. In this study, we employed a multi-objective Particle Swarm Optimization algorithm to inversely design a grating-structured metamaterial absorber based on MXene and investigated its optical properties using the Finite-Difference Time-Domain method. Our results demonstrate that the designed metamaterial absorber achieves exceptional absorption (97.2 %) across the entire solar radiation spectrum, and low average emissivity (4.9 %) in the infrared region. Theoretical analysis reveals that the broadband absorption arises from the synergistic effect of multiple resonant modes. Furthermore, the MXene-based metamaterial absorber exhibits wide-angle absorption at an incident angle of 60° with minimal polarization dependence. In regions rich in solar radiation, this absorber has the potential to save approximately 1924.7 kWh/m² of energy annually. These findings hold significant implications for applications in solar photovoltaics and optoelectronic conversion.