hence have drawn a lot of attention as down-conversion materials for white lightemitting diodes (WLEDs). [7][8][9][10] For practical applications, the cost-effectiveness, the optical performance, and the stability of PQDs should be further improved. [4] Particularly, PQDs suffer from low chemical and optical stabilities, resulting in their fast degradation under exposure to moisture, heat, and light irradiance. [11,12] Accordingly, PQDs exhibit much lower stability than conventional rare-earth-based phosphor materials. [13,14] Current research efforts therefore aim at enhancing the stability of PQDs by covering them in inorganic materials, including CdS, [15] zeolite, [16,17] glass, [18,19] CaF 2 , [20] Al 2 O 3 , [21][22][23] SiO 2 , [24][25][26][27][28][29] and TiO 2 . [30] Generally, the protective shells of PQDs are prepared using these inorganic materials by in situ synthesis. While protected PQDs with high chemical, thermal, and irradiation stabilities have been obtained, [28] the water stability of PQDs prepared with these inorganic shells still indicate a lot of room for improvement. For instance, the PL intensity of CaF 2 shell-integrated green PQDs reduces to <50% after a water-resistance test of ≈40 h. [20] Consequently, and until now, PQDs with high water stability are achieved by embedding them in enclosed organic polymer and glass matrices. [18,19,[31][32][33][34][35][36][37][38][39] The hydrophobic surface and dense polymer chains of the matrix can effectively protect the PQDs from the external environment, considerably enhancing their
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 newfunctions 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.
