Preparation and optical properties of CsPbBr3 nanocrystals co coated with SnOx/mesoporous ZSM-5 zeolite

A dual-shell hierarchical protection strategy combining non-hydrolytic sol-gel derived SnO x coating and mesoporous ZSM-5 encapsulation was proposed to simultaneously boost luminescence efficiency and environmental stability of CsPbBr 3 nanocrystals. • Conformal amorphous SnO x layer uniformly passivates surface defects of CsPbBr 3 , the optimized CsPbBr 3 @SnO x sample achieves a PLQY increase from 64% to 74%, and retains 55% and 47% initial PL intensity after 120 min immersion in water and ethanol, respectively. • Secondary encapsulation within hierarchical micro-mesoporous ZSM-5 further reinforces structural robustness, raising the maximum PLQY of CsPbBr 3 @SnO x @ZSM-5 composite up to 76%. The composite exhibits negligible emission shift after 120 min treatment in water, ethanol and tetrahydrofuran, with outstanding retention of luminescence signal. • White light-emitting diode (WLED) assembled with CsPbBr 3 @SnO x @ZSM-5 green phosphor and commercial red K 2 SiF 6 :Mn 4+ phosphor delivers balanced white emission with CIE coordinates of (0.310, 0.307), a color rendering index of 70, correlated color temperature of 6651 K and luminous efficiency of 26.76 lm W −1 , demonstrating great potential for solid-state lighting applications. All-inorganic CsPbBr 3 perovskite nanocrystals (NCs) exhibit excellent optoelectronic properties but suffer from severe instability against moisture, oxygen, heat, and polar solvents due to their ionic lattice, surface defects, and labile ligands, leading to rapid ion migration and photoluminescence quenching. In this work, a dual-shell engineering strategy based on a non-hydrolytic sol-gel (NHSG) route was developed to construct CsPbBr 3 @SnO x and CsPbBr 3 @SnO x @ZSM-5 composite nanostructures. An SnO x -rich interfacial layer was formed on the CsPbBr 3 NCs and subsequently coupled with hierarchical ZSM-5 confinement, contributing to surface-defect passivation and stabilization of the interfacial chemical environment while preserving the perovskite crystal structure and emissive centers. At an optimized Sn/Pb molar ratio of 0.5, the photoluminescence quantum yield (PLQY) increased from 64% to 74%, and an optimal reaction time of 10 min yielded the highest emission efficiency (PLQY≈70%). Moreover, the SnO x coating significantly enhanced environmental stability, with CsPbBr 3 @SnO x retaining 55% and 47% of its initial PL intensity after 120 min exposure to water and ethanol, respectively. Subsequently, hierarchical encapsulation within mesoporous ZSM-5 further reinforced structural robustness and optical stability. The resulting CsPbBr 3 @SnO x @ZSM-5 composite achieved an enhanced PLQY of 76% and exhibited negligible emission shift after immersion in water, ethanol, and tetrahydrofuran for 120 min. In addition, the composite demonstrated excellent stability under continuous UV irradiation, thermal treatment, and ambient storage conditions. Finally, a white light-emitting diode (WLED) device fabricated using CsPbBr 3 @SnO x @ZSM-5 delivered stable white emission with Commission Internationale de l'Éclairage (CIE) coordinates of (0.310, 0.307), a color rendering index (CRI) of 70, a correlated color temperature (CCT) of 6651 K, and a luminous efficiency of 26.76 lm W −1 . These results highlight the effectiveness of the dual encapsulation strategy in simultaneously enhancing the photoluminescence performance and environmental stability of perovskite nanocrystals, providing a viable route toward high-performance optoelectronic and solid-state lighting applications. Download: Download high-res image (303KB) Download: Download full-size image