Embedded growth of colorful CsPbX3 (X = Cl, Br, I) nanocrystals in metal-organic frameworks at Room Temperature

Herein, we develop a novel strategy for preparing all-inorganic cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals (NCs)@Zn-based metal-organic framework (MOF) composites through interfacial synthesis. The successful embedding of fluorescent perovskite NCs in Zn-MOFs is due to the in situ confined growth, which is attributed to the re-nucleation of water-triggered phase transformation from Cs4PbBr6 to CsPbBr3. The controllable synthesis of mixed-halide based composites with various emission wavelength can be achieved by adding the desired amount of halide (Cl or I) salts in the re-nucleation process. More importantly, the anion exchange reaction is inhibited among various composites with different halogen atoms by being trapped in MOFs. Besides, a white light-emitting diode (WLED) is produced using a blue LED chip with the green-emitting and red-emitting composites, which has a color coordinate of (0.3291, 0.3272) and a wide color gamut. This work provides a novel route to achieving perovskite NCs growth in MOFs, which also can be extended to the other NCs embedded in frames as well.