Highly Efficient and Water‐Stable Lead Halide Perovskite Quantum Dots Using Superhydrophobic Aerogel Inorganic Matrix for White Light‐Emitting Diodes

Abstract At present, most of lead halide perovskite quantum dots (PQDs) embedded in an enclosed organic polymer or glass matrix can achieve high water stability, yet this limits their subsequent integration with light‐emitting diodes (LEDs) and other functional materials. Herein, a postadsorption process using superhydrophobic aerogel inorganic matrix (S‐AIM) with open structures is presented to enhance water stability of PQDs and compose new functions to them such as magnetism. The CsPbBr 3 PQDs integrated with the S‐AIM (AeroPQDs) exhibit a high relative photoluminescence quantum yield (PLQY, 75.6%) of 90.9% compared to pristine PQDs (PLQY, 83.2%). They preserve their initial PL intensity after 11 days of soaking in water and achieve a high relative PLQY stability (50.5%) after soaking for 3.5 months. The hydrophobic (rough) surface of the matrix, its pores with a well‐matched mean diameter that promotes the homogeneous integration of PQDs and hinders the penetration of water as well as the oleophylic functional groups covering the surface of these pores are the three factors responsible for the high water stability. Finally, AeroPQDs are easily integrated with other functional nanomaterials, such as Fe 3 O 4 nanoparticles for magnetic manipulation, due to their open structure.