Highly luminescent lead bromine perovskite via fast and eco-friendly water-assisted mechanochemical method

All-inorganic cesium lead halide perovskite nanocrystals (CPeNCs) have aroused tremendous research attention due to their excellent photophysical properties. Here, we report an eco-friendly and fast water-assisted mechanochemical synthesis of CsPbBr 3 perovskite functionalized by oleic acid (OA) and hydroxyl groups (OH). Owing to the water exfoliation and mechanical shearing force, the CsPbBr 3 bulks quickly transformed into rectangular CsPbBr 3 particles in 10 min with a bright green emission (λ em  = 525 nm) and a high photoluminescence quantum yield (PLQY) up to 53%. Impressively, the functionalized CsPbBr 3 retains their bright green emission in ethanol after 360 days, showing high ethanol resistance. Thus, an alcohol solubility and easy film-forming transparent polymer of polyvinyl butyral (PVB) is directly employed to encapsulate functionalized CsPbBr 3 in ethanol solution. The obtained CsPbBr 3 /PVB composite film shows excellent water resistance, whose photoluminescence intensity drops only 20% after 60 h in water. The composite film was demonstrated as color converter layers of white light-emitting diodes device with color coordinates of (0.329, 0.321). This work not only offers a green synthesis method for perovskite fluorescent material, but also helps to address their long-term stability in polar solvents towards their various applications.