Impact of Shape Variations on Thermo-Optical Response of Selected PhC Absorbers in Solar Thermophotovoltaic Converters

Two-dimensional (2D) photonic crystals(Phcs) have attracted significant interest for their potential to efficiently absorb sunlight for energy harvesting. In this study, we investigate the absorption properties of three different tungsten absorbers with similar geometric features. Our results reveal that, for a given height and cross-sectional dimension, the nano-cone absorber demonstrates superior performance. We then examine the optical and thermal responses of the nano-cone absorber for use in a solar thermophotovoltaic(STPV) system. The effects of reflection and thermal radiation from both the top and bottom of the nanostructure are analyzed. Additionally, we compare the total efficiency of the nano-cones with truncated versions under varying sunlight concentration factors. The temperatures of the structures are modeled and determined based on the absorbed light. We show that concentration is a nonlinear factor that significantly influences the overall absorber efficiency.