The CsPbBr₃/Cs₄PbBr₆ perovskite composite material has received wide attention due to its good stability and photoelectric properties, and it is promising to appear in various photoelectric applications. However, there are still some challenges in how to control the synthesis of this material and obtain the balance between high fluorescence efficiency and well stability. In this study, we proposed a rapid anti-solvent vapor-assisted method to prepare CsPbBr₃/Cs₄PbBr₆ microcrystals (MCs) with hexagonal tower structure. It is found that oleic acid and oleamine can effectively control the morphology, grain size and optical properties of the material. This unique hexagonal tower structure CsPbBr₃/Cs₄PbBr₆ MCs has excellent optical properties, showing strong green emission at 514 nm and PLQY of 78.4 ± 4.3%, with a narrow full width at half maximum value of 20 nm. In addition, environmental stability experiments have shown that after 6 months of storage under 50% relative humidity, the PL strength loss is lower than 20%.

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