Enhancing the Water Resistance and Stability of CsPbBr₃ Perovskite Quantum Dots for Light-Emitting-Diode Applications through Encapsulation in Waterproof Polymethylsilsesquioxane Aerogels

Abstract

Highly stable all-inorganic perovskite quantum dot/polymethylsilsesquioxane aerogel (CsPbBr₃/PMSQ AG) composites were first produced using two-step hot-injection and encapsulation processes by embedding green-emitting CsPbBr₃ PQDs into modified hydrophobic mesoporous silica AGs. The unique structure of the composites not only considerably enhances the chemical stability of CsPbBr₃ PQDs against moisture, humidity, and blue-light irradiation in air but also prevents anion exchange reactions during light-emitting diode (LED) manufacturing processes. In addition, the composition-optimized CsPbBr₃/PMSQ AG exhibited excellent stability when soaked in water for more than 14 days and retained half of its initial intensity. Finally, white LED devices were fabricated by combining a blue-emitting GaN-based chip, green-emitting CsPbBr₃/PMSQ AG, and red-emitting K₂SiF₆:Mn⁴⁺ phosphors.