Fabrication of high-performance CsPbBr₃ perovskite quantum dots/polymer composites via photopolymerization: implications for luminescent displays and lighting

The all-inorganic perovskite quantum dots (QDs) and cesium lead halide QDs (CsPbBr₃ QDs) are the topics of interest in the field of optoelectronic devices as they show superior photoluminescence quantum yield and tuneable optical bandgaps. However, the long-term stability issue limits their wide applications. In this research, we fabricate CsPbBr₃ QDs/polymer composites through a photopolymerization strategy, during which CsPbBr₃ quantum dots serve as photoinitiators in combination with the additives [diphenyliodonium hexafluorophosphate (Iod) or ethyl 4-(dimethylamino) benzoate (EDB)], to trigger polymerization processes as well as serve as highly efficient emitters in the resulted composites. More importantly, two types of additives are investigated to optimize the polymerization processes and the final product performance. In addition, steady-state photolysis, fluorescence quenching measurements, and electron spin resonance spin trapping technologies are applied to evaluate the relevant photochemical mechanism, and these demonstrate that their photoinitiation efficiency is greatly enhanced with the addition of the additives. Specifically, the addition of Iod results in higher photoinitiation ability compared to that of EDB, which can be explained by the absence of back electron donation in the CsPbBr₃ QDs/Iod combination. Therefore, the strategy provided here is that CsPbBr₃ QDs play a dual role in acting as both the efficient photoinitiators and the emitters to yield the desirable composites with superior photoluminescence properties, which are promising to enhance the long-term stability and device performance for the applications of luminescent displays and lighting.

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