Optimizing Horticulture Luminescent Solar Concentrators via Enhanced Diffuse Emission Enabled by Micro-Cone Arrays

Optimizing the photon spectrum for photosynthesis and improving crop yields presents an efficient pathway to alleviate global food shortages. Luminescent solar concentrators (LSCs), consisting of transparent host matrices doped with fluorophores, show excellent promise to achieve the desired spectral tailoring. However, conventional LSCs are predominantly engineered for photon harvesting, which results in a limited outcoupling efficiency of converted photons. Here, we introduce a scheme to implement LSCs into Horticulture (HLSC) by enhancing light extraction. The symmetry of the device is disrupted by incorporating micro-cone arrays on the bottom surface to mitigate Total Internal Reflection (TIR). Both Monte Carlo ray tracing simulations and experimental results have verified that the greatest enhancements in converted light extraction, relative to planar LSCs, are achieved using micro-cone arrays (base width 50 um, aspect ratio 1.2) with extruded (85.15% improvement) and protruded (66.55% improvement) profiles. Angularly resolved transmission measurements show that the HLSC device exhibits a broad angular radiation distribution. This characteristic indicates that the HLSC device emits diffuse light, which is conducive to optimal plant growth.