Recyclable luminescent solar concentrator from lead-free perovskite derivative

Luminescent solar concentrators (LSCs), which balance transparency with photovoltaic capabilities, are emerging as pivotal solutions in the quest for self-sufficient green energy. Using semitransparent fluorescent glasses, LSCs absorb a portion of sunlight and undergo photoluminescence (PL), which is then conducted to the solar cells integrated on the edges for optical-electrical conversion. As a key component, in previous reports, the fluorescent glasses were fabricated by embedding nanocrystals (NCs). Despite the relatively mature synthesis protocols for NCs at the laboratory stage, their protracted fabrication durations, massive solvent consumption, and constrained chemical yield result in elevated preparation costs, which present substantial challenges for future large-scale production of LSCs.

 

Moreover, the embedded emitters are challenging to segregate and recycle, which leads to a disposable use characteristic, necessitating re-synthesis and re-embedding once the glasses are damaged. By comparison, one-step synthesis of fluorescent glasses by simply thermal treatment is more desirable for low-cost and mass-scale production, and exploring such new materials and corresponding preparation schemes is considered crucial to potential industrialization. Additionally, in the age of low-carbon and sustainable globalization, heightened attention should be given to the recyclability of these novel fluorescent glasses once damaged or discarded, thereby eliminating disposable use, resource squandering or heavy metal pollution.

 

In a new paper published in Light: Science & Applications, a team of scientists, led by Professor Xiyan Li from Nankai University (P.R. China) and co-workers have synthesized the yellow emissive ETP₂SbCl₅ phosphor with a near-unity PLQY by a simple solution process at room temperature, of which the glass phase could be obtained by further thermal treatment. The as-fabricated ETP₂SbCl₅-based LSCs exhibited the highest power conversion and optical efficiencies of ~5.56% and ~32.5%, respectively, on a 3×3×0.5 cm³ fluorescent glasses. Besides the self-healing property, reversible transitions between phosphor and glass phases have also been detected. These scientists summarize this study:

 

“We first visualize the distortion of [SbCl₅] pyramid during the phase transition from α, through β, to G-ETP₂SbCl₅ by Ab initio molecular dynamics (AIMD), and further reveal its effects on broadened and red-shifted emission.”

 

“The fabricated fluorescent glasses exhibit an average vision transmission of 78.3%. They could effectively absorb the UV light (< 420 nm) and realize the self-trapped exciton (STE) emission with a PLQY of ~52.6%. Taking advantage of their great waveguide performance, a portion of sunlight and the fluorescence could be conducted to the photovoltaic devices that coupled on the edges. And we achieve the highest power conversion and optical efficiencies of ~5.56% and ~32.5%, respectively, on a 3×3×0.5 cm³ LSC device.”

 

“Besides the self-healing property at 200 ^oC, reversible transitions between phosphor and glass phases have been detected. Even after undergoing 10 cycles of phosphor-glass transitions, the final recycled phosphors still maintained ~95% of their initial PL performance, enabling them to be further used in other fields, such as phosphor converted-LED or anti-counterfeiting, etc., as effective as freshly synthesized phosphors, underscoring its role in sustainable energy solutions for the low-carbon era.” the scientists forecast.

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