Micro-cone arrays enhance outcoupling efficiency in horticulture luminescent solar concentrators

A Comparison of the Optical Properties of Fibre-Based Luminescent Solar Concentrators and Transparent Wood Towards Sustainable Waveguides

Aiming at net-zero emissions, most international and national policies focus on sustainable development goals. Hence, there is an immediate need for replacing carbon-intensive materials with biomaterials. In this respect, this article presents a road-map for moving from polymeric to sustainable waveguides in optical devices. Previous reports indicate that luminescent fibres exhibit better photon concentrations of nearly 30%-33% higher than flat-plate polymeric waveguides. It is also verified that the photon in-out ratio increases by 3.44 times when the waveguide geometry is changed from planar to an equivalent area of fibre bundle with the same luminophore. Meanwhile, transparent wood (Twood) is gaining attention as a green alternative to acrylic sheets. The structure and function of transparent wood conforms well with the fibre-based waveguides of luminescent solar concentrators (LSCs). Therefore, it is intriguing to compare Twood with intrinsic micro fibrillary interior with fibre-based LSC as a natural alternative. This review provides an in-depth analysis, emphasizing the benefits and associated challenges in using cylindrical concentrators over planar LSCs. The paper collects and compares the phenomenon of light guiding of cylindrical and fibre-based LSCs with that of Twood. It is important to consider the key points discussed here while making a transition towards sustainable waveguides.

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

Optimizing the photon spectrum for photosynthesis concurrently with improving crop yields presents an efficient and sustainable 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 concentration, 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 microcone arrays on the bottom surface to mitigate total internal reflection. 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 microcone arrays (base width 50 μm, aspect ratio 1.2) with extruded and protruded profiles (85.15 and 66.55% improvement, respectively). 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.

Exploring light-emitting diode pumped luminescent concentrators in solid-state laser applications

In the past, there were limited efforts to use light-emitting diodes (LEDs) for pumping solid-state lasers. However, these attempts were overshadowed by the introduction of laser diodes, which offered more favourable pumping conditions. Nevertheless, recent advancements in high-power LEDs, coupled with the utilization of luminescent concentrators (LC), have paved the way for a novel approach to pump solid-state lasers. The combination of LEDs and LC in this LED-LC system presents several advantages, including enhanced ruggedness, stability, and cost-effectiveness compared to other laser pumping methods. This review explores the various techniques employed to pump solid-state lasers using LED-LC as a pump source, along with improvements made to enhance the brightness of LEDs in this context.

A comprehensive dataset of photonic features on spectral converters for energy harvesting

Building integrated photovoltaics is a promising strategy for solar technology, in which luminescent solar concentrators (LSCs) stand out. Challenges include the development of materials for sunlight harvesting and conversion, which is an iterative optimization process with several steps: synthesis, processing, and structural and optical characterizations before considering the energy generation figures of merit that requires a prototype fabrication. Thus, simulation models provide a valuable, cost-effective, and time-efficient alternative to experimental implementations, enabling researchers to gain valuable insights for informed decisions. We conducted a literature review on LSCs over the past 47 years from the Web of ScienceTM Core Collection, including published research conducted by our research group, to gather the optical features and identify the material classes that contribute to the performance. The dataset can be further expanded systematically offering a valuable resource for decision-making tools for device design without extensive experimental measurements.