Highly sustainable multilayer fluorescent devices for solar energy harvesting

Luminescent Solar Concentrators (LSCs) are slab devices capable of concentrating sunlight, exploiting the emissive properties of fluorescent systems. Because of their appealing aesthetic characteristics, lightweight, and the ability to work in diffuse light, they are promising candidates for the development of building-integrated and distributed urban photovoltaic systems. To overcome the inherent limitations of single-dye LSCs in terms of spectral coverage and efficiency, this paper explores the development and performance of bulk LSCs fabricated with r-PMMA using the dyes DQ1 and BDT-H2 in both monolayer and multilayer configurations. Concentrations ranging from 200 to 400 ppm were investigated, yielding exceptional photophysical properties, including ≈ 90% s and close to 45% for DQ1 systems. For BDT-H2-based LSCs, an of 8.6% was achieved. Notably, the emission peak of DQ1 and the absorption band of BDT-H2, both centred around 530 nm, supported a synergistic multilayer design. When stacked, the multilayer configuration with the DQ1 layer positioned atop the BDT-H2 layer exhibited superior performance, achieving a maximum of 9.2%. This enhanced efficiency was attributed to three key factors: the high conversion efficiency of DQ1 within its absorption range, the reabsorption of DQ1-emitted photons by BDT-H2, and the expanded absorption range from the overlap of the dyes’ spectra. Graphic abstract: (Figure presented.)