In Situ Encapsulation of High‐Efficiency CsPbBr ₃ Quantum Dots in Silica Aerogel for Ultra‐Stable Luminescence in Aqueous and High‐Temperature Environments

ABSTRACT All‐inorganic perovskite quantum dots (PQD) have become the most promising next‐generation luminescent material due to their excellent luminescent properties. However, as an ionic crystal, their stability is the biggest problem for their large‐scale application. Especially, it is a huge challenge to use them in water or at high temperatures. This study proposes a strategy for the simultaneous synthesis of CsPbBr 3 quantum dots and silica aerogels (SiO 2 AG). During the formation of the aerogel network, the quantum dot precursor solution is confined within nanoscale silica aerogel “microcapsules”; upon heating, the quantum dots undergo nucleation and growth within these “capsules”, simultaneously completing the synthesis and protection of the quantum dots. The experimental results show that the photoluminescence properties of CsPbBr 3 quantum dots and SiO 2 aerogel （CsPbBr 3 @SiO 2 AG) Composites material prepared by this method remain unchanged after heat treatment at 400°C for 8 h, and the photoluminescence quantum yield (PLQY) can reach 99.1%. Even after direct immersion in water and natural evaporation, the luminescent properties remain above 39%, and the precipitation of Pb 2+ is effectively inhibited. This material provides strong support for the large‐scale application of perovskite quantum dots, especially in various emerging fields under extreme conditions.