Synopsis

Climate change stands as one of the most pressing challenges of our time, demanding a significant reduction in CO2 emissions resulting from human activities. This urgency has driven the scientific community to explore new innovative and efficient methods to harness renewable energy sources, such as solar energy, to decrease dependence on fossil fuels and ultimately replace them. Solar fuels, generated through processes like photocatalysis, photoelectrocatalysis, or biological/biochemical systems, hold significant potential to meet the international community’s goals. By emulating natural photosynthesis, this approach aims to convert CO2 into valuable sustainable energy carriers for energy-intensive and transport industries. Among various reactor designs, the integration of light-harvesting systems, including optical devices (lenses or mirrors) and chemical concentrators (organic dyes as luminescent solar concentrators, LSCs), represents a novel advancement to enhance process efficiency.

Luminescent solar concentrators (LSCs) rely on a technology studied since the 1970s to develop semi-transparent and cheap photovoltaic devices that capture and concentrate both direct and diffuse solar radiation onto small solar cells for energy conversion. A typical LSC system consists of a slab of transparent polymer matrix (the host) in which fluorescent substance (the guest) is embedded. These substances are typically organic dyes or quantum dots. To obtain high-performance LSC devices, a careful study of the materials used for their assembly must be conducted. Selecting an appropriate polymer matrix and solvent are crucial to ensure a well-dispersed LSC layer and maintain its optical properties.
This research aims to identify the most suitable and green solvent for chemical compatibility with LSC materials under the Nefertiti project (GA 101022202). Initially, the organic dye was chosen then Hansen Solubility Parameters (HSPs) approach was employed to identify potential green solvents and alternative polymer matrix to enhance the optical properties and durability of LSC coatings. This study seeks to demonstrate that HSP software is a robust and reliable tool for selecting ingredients to design a greener LSC coating.

In the first phase of the research, a comprehensive analysis of the materials used in LSC device assembly was conducted to ensure optimal performance. This included a detailed evaluation of the polymers and green solvents selected for dispersion using the Hansen solubility sphere method. Finally, the most suitable combinations were applied using a low-pressure high volume (LPGH) spray gun. The resulting coatings were characterized in terms of their thickness, photoluminescence yield and UV-Visible absorbance properties.

Keywords: luminescent solar concentrators, Hansen solubility, green solvents, photoluminescent yield, optical properties.

Acknowledgements: The research leading to these results has received funding from the European Union’s H2020 research and innovation programme under Grant Agreement No. 101022202 (Nefertiti). The output reflects the views only of the authors, and the European commission cannot be held responsible for any use which may be made of the information contained therein.