Sustainable luminescent solar concentrators with superior photodegradation resistance employing heptagon-embedded polycyclic aromatic dicarboximides as emitters

Luminescent Solar Concentrators (LSCs) are a type of light concentrating devices which offer several advantages over other optical methods, like the possibility of working with diffuse light and the appealing aesthetics, which makes them an ideal technology for their integration in building's facades of urban settings. In order to improve their effectiveness and foster a large-scale adoption, solutions to lower the impact of their production and extend their lifetime would be extremely beneficial. Photostability is crucial for fluorophores used in LSCs, as they have to endure extended sunlight exposure over years. UV radiation can alter the structure of organic emitters, reducing LSC efficiency and causing panel replacement, with economic costs and environmental implications. In this study, two push-pull dyes comprising distorted heptagonal inclusions—namely, Peri2F and Nap2Car—were investigated as emitters for bulk PMMA-based LSCs fabricated employing chemically regenerated monomers (r-MMA). Compared to the use of virgin monomer, the Global Warming Potential of slab production is about four times smaller, thereby enhancing the sustainability and encouraging circularity of large-scale LSC fabrication. The most effective Peri2F/r-PMMA system yielded an ηdev of 0.7%, lower than that of devices comprising the state-of-the-art emitter LR305. Remarkably, however, Peri2F showed a far superior resistance to photodegradation. Forecast analysis estimated that the LSC containing 100 ppm of Peri2F can match LR305 performance in r-PMMA after about 1 year of use, with less than 2% decrease in initial emission intensity.