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

## TL;DR

A new method creates perovskite quantum dots in rubber for efficient, durable white LEDs with excellent light emission and stability.

## Contribution

A solvent-free mechanochemical strategy enables in situ synthesis of perovskite quantum dots in elastomer for scalable, high-performance white LEDs.

## Key findings

- CsPbBr3 quantum dots with 91% photoluminescence quantum yield and 1189 ns lifetime were synthesized in brominated butyl rubber.
- Composite films retained over 90% initial intensity after 30 days of ambient storage and water immersion.
- Flexible white LEDs achieved 132% NTSC color gamut and a color-rendering index of 55.7.

## Abstract

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.

A solvent‐free, open‐mill shear protocol nucleates 2.6 nm CsPbBr3 QDs uniformly within brominated butyl rubber. The emitters showed 91% PLQY, 1189 ns lifetime, and > 90% retention after 30‐day ambient storage and water immersion, respectively. Board‐to‐board forms 17 × 17 cm2 flexible films for 132% NTSC white LEDs, scintillators, and stretchable displays.