Perovskite CsPbBr₃ Quantum Dots on Aminated Silica with Enhanced Stability for Blue Light-Emitting Diode and Anti-Counterfeiting Applications

Inorganic perovskite quantum dots (PQDs), specifically CsPbX3 (X = Cl, Br, or I), have attracted considerable interest for their exceptional optoelectronic properties. However, their development is constrained by instability arising from particle mobility. The tendency of small-sized PQDs to aggregate into larger green-emitting PQDs presents a significant challenge to the widespread application of blue-emitting CsPbBr3 PQDs, particularly in scenarios demanding pure blue light emission. To tackle this challenge, we utilized a straightforward yet efficient synthesis approach to immobilize and encapsulate blue-emitting CsPbBr3 PQDs onto APTES-capped silica microspheres. In contrast to CsPbBr3 PQDs, CsPbBr3-A-SiO2 composites display outstanding stability under UV exposure, heat, and aqueous conditions, consistently maintaining a single blue emission peak in the photoluminescence spectrum, accompanied by an extended fluorescence lifetime. Transmission electron microscope analysis revealed the transformation of CsPbBr3 from dispersed quantum dots to aggregated nanostructures or nanorods with time, while encapsulated quantum dots maintained uniform dispersion. By encapsulating CsPbBr3-A-SiO2 composites on a 310 nm UV chip, stable blue light-emitting diodes with color coordinates approximately at (0.148, 0.05) can be fabricated. The synergistic application of unstable CsPbBr3 PQDs and stable CsPbBr3-A-SiO2 composites effectively enhance anticounterfeiting measures, information encryption, and digital display technologies. Integrating stable and unstable materials is anticipated to show promise in information encryption, security, and various other domains.