High-efficiency full-spectrum solar utilization via a novel continuous spectral splitting concentrator: design, optical validation, and system-level performance assessment

Spectral Beam Splitting (SBS) is a promising technology to precisely manage the solar spectrum and cascaded utilization of solar energy. However, conventional discrete SBS techniques experience an exponential rise in optical loss with successive splitting, thereby constraining the maximum number of feasible divisions. To address these challenges, this paper proposes a Novel Continuous Spectral Splitting Concentrator (CSSC) based on a refractive prism array. The CSSC enables an approximate spatial separation of spectral splitting and light concentration along orthogonal directions, generating a continuous “rainbow-like” spectrum with improved spectral resolution. A comprehensive optical-electrical model was developed and validated against experimental results, showing a Root Mean Square Deviation of 8.2% in energy flux distribution. Through a comprehensive parametric study, we identified the trade-offs between the spectral splitting coefficient and optical efficiency, determining an optimal prism apical angle limit of 21.5°. The optimized CSSC achieves an optical efficiency of 85.2% in the present configuration. The system achieved a high spectral resolution with a Full Width at Half Maximum (FWHM) of approximately 110 nm. A coupled optical-electrical case study indicates that integrating the proposed CSSC with a laterally arranged InGaP/GaAs/Ge cell array could achieve a photovoltaic efficiency of 37.0% under 400× concentration. These results suggest that the CSSC can serve as a promising optical platform for spectrum-selective solar-energy utilization.