Aqueous-stable perovskite quantum dots: degradation mechanisms, stabilization strategies, and applications

Metal halide perovskite quantum dots (PQDs) have emerged as next-generation luminescent nanomaterials owing to their high photoluminescence quantum yield (PLQY), narrow emission bandwidth, and tunable bandgap via compositional engineering. However, their intrinsic ionic crystal structure renders them highly susceptible to moisture, leading to rapid structural degradation and deterioration of optical properties in aqueous environments. This instability significantly limits their practical application in water-based systems such as biosensing, environmental monitoring, and photocatalysis. In this review, we examine the fundamental mechanisms of water-induced degradation in PQDs and highlight the critical need for achieving aqueous dispersibility. We then focus on two representative stabilization strategies: (1) surface modification via ligand exchange and (2) physical protection through silica shell encapsulation. The advantages, limitations, and design considerations of each approach are comparatively analyzed to provide insights into the development of next-generation water-stable perovskite systems.