Deep Blue Emitting Lead Halide Perovskite and Metal‐Organic Framework Glass Composites Through Mechanochemistry

Abstract Mixed‐halide perovskites are promising materials for optoelectronic applications due to their tunable bandgaps and high photoluminescence quantum yields. However, these materials face challenges such as phase segregation under excitation and instability when exposed to polar solvents, especially in blue‐emitting regions. In this study, a facile mechanochemical synthesis method is developed to produce CsPb(Br_xCl_1‐x)₃ ‐ MOF (Metal‐organic framework) glass composites. By precisely controlling the halide composition and optimizing milling conditions, glass composites containing quantum‐confined perovskite particles with significantly improved phase stability, photoluminescence (PL), and solvent resistance are achieved. Notably, the composite can maintain up to 77% PL efficiency after soaking in water for a year. Structural and optical analyses revealed that the mechanochemical process fosters interfacial bonding between the perovskite and MOF glass, effectively regulating perovskite particle size and passivating surface defects. To demonstrate practical applications, violet and blue light‐emitting diode (LED) devices are fabricated, achieving CIE color coordinates of (0.152, 0.031) and (0.134, 0.045), respectively. This work offers a scalable, eco‐friendly approach to synthesizing stable, high‐performance blue‐emitting perovskites, paving the way for their integration into next‐generation optoelectronic devices.