A Facile Synthesis of Water‐Resistant CsPbBr3 Perovskite Quantum Dots Loaded Poly(methyl methacrylate) Composite Microspheres Based on In Situ Polymerization

Abstract In this paper, a facile synthesis of water‐resistant CsPbBr 3 perovskite quantum dots (PQDs) loaded poly(methyl methacrylate) (PMMA) composite microspheres (CsPbBr 3 @PMMA) is reported. The method is based on the precipitation polymerization of methyl methacrylate in hexane in the presence of CsPbBr 3 PQDs and stabilizer. The CsPbBr 3 @PMMA microspheres show a tunable size and a narrow size distribution, with the CsPbBr 3 PQDs being uniformly dispersed in the PMMA microspheres. The effective incorporation of PQDs is attributed to the strong coordination interactions between Pb ions on the surface of PQDs and carbonyl groups (CO) from PMMA. Based on this mechanism, multicolor composite microspheres can be easily prepared through absorbing CsPbX 3 (X = Cl, Br, I) PQDs into blank PMMA microspheres. Protected by the PMMA microspheres, the imbedded CsPbBr 3 PQDs show improved water resistance and storage stability. Further, a wide‐color‐gamut (129%) white light‐emitting diode (LED) is demonstrated by combining the green‐emitting CsPbBr 3 @PMMA composite microspheres and red‐emitting K 2 SiF 6 : Mn 4+ with a blue LED, which enables to be used as backlights for liquid crystal displays.