Highly bright and ultra-stable cyan-emitting perovskite quantum dots encapsulated in zeolitic imidazolate framework-11 for advanced optoelectronic applications

Lead halide perovskite quantum dots (PeQDs) exhibit excellent optical properties and have garnered impressive attention in displays and lighting. However, the inherent aggregation and poor stability of PeQDs severely limit their practical applications in various fields. Herein, we report an ultrasound-assisted microemulsion (US-MEs) in situ synthesis to prepare highly bright, pure and stable CH 3 NH 3 PbBr 3 (MAPbBr 3 ) QDs encapsulated within the porous zeolitic imidazolate framework-11 (ZIF-11) for the first time. The MAPbBr 3 @ZIF-11 composites demonstrated distinctive narrow-band cyan emission at 505 nm with a full width at half maximum (FWHM) of 18 nm and an ultra-high fluorescence quantum yield exceeding 85 %. Notably, the composites also showed outstanding solvent, thermal, UV radiation and environmental stability. Thanks to the framework protection and inner passivation for uniformly dispersed MAPbBr 3 QDs, they present premium optical properties and superior stability, outperforming previously reported green emissive composites. Furthermore, we successfully demonstrated the feasible applications of MAPbBr 3 @ZIF-11 composites in fluorescent probes, information encryption and wearable sensors. The facile and effective synthetic strategy proposed in our work provides a guideline for achieving high quality PeQDs based on nanoconfined approach, thus unlocking their full potential in multifunctional applications.