Large-Scale In Situ Formation Perovskite Quantum Dots/Elastomer Composite for High-Performance White Light-Emitting Diodes.

Metal halide perovskite quantum dots (PQDs) are promising emitters for light conversion but suffer from poor compatibility and scalability in polymer composites. Herein, we report a one-step, solvent-free mechanochemical strategy for the in situ synthesis of CsPbX3 (Br/Cl) QDs within halogenated butyl rubber (HIIR) via open-mill shear, yielding monodisperse 2.6 nm CsPbBr3 QDs uniformly embedded in a topological entanglement network. The CsPbX3/HIIR composite exhibited a narrow emission at 515 nm (FWHM 17 nm), photoluminescence quantum yield of 91%, and ultra-long lifetime of 1189 ns. Spectroscopic and mechanistic studies revealed that the in situ-generated IIR-OOCC17H35 chains create an interfacial allyl ester passivation layer that suppresses surface traps and blocks H2O/O2 ingress. Consequently, films retained > 90% initial intensity after 30-day ambient storage, 99.8% after 30-day water immersion, and 44% after 500 h blue-light irradiation (5000 nit). Flexible white LEDs achieved standard white emission (0.333, 0.338), color-rendering index of 55.7, and wide color gamut of 132% NTSC. The low-cost and high-efficiency manufacturing process can be readily scaled to 17 × 17 cm2 films, offering an industrially viable route for stretchable displays, X-ray scintillators, and wearable photonics.