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 CsPbX 3 (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 CsPbBr 3 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 CsPbBr 3 PQDs onto APTES-capped silica microspheres. In contrast to CsPbBr 3 PQDs, CsPbBr 3 -A-SiO 2 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 CsPbBr 3 from dispersed quantum dots to aggregated nanostructures or nanorods with time, while encapsulated quantum dots maintained uniform dispersion. By encapsulating CsPbBr 3 -A-SiO 2 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 CsPbBr 3 PQDs and stable CsPbBr 3 -A-SiO 2 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.