Solid State Melting Confinement Reaction Synthesis of CsPbBr3 Quantum Dots Embedded in Mesoporous SiO2 Microspheres for Light‐Emitting Diodes

Abstract Perovskite quantum dots (PQDs) have attracted widespread attention in optoelectronic fields due to their excellent optical properties. However, their instability issue hampers their further development and practical application. Herein, CsPbBr 3 PQDs embedded in mesoporous SiO 2 microspheres (CsPbBr 3 PQDs/MSs) are prepared by the high‐temperature solid‐phase melting method due to the confinement effect. The prepared CsPbBr 3 PQDs/MSs are treated by saturated Na 2 SO 4 to form PbSO 4 precipitation to fulfill the mesoporous gap. And such treatment endows the QDs with excellent water, light irradiation, and heating stability. The prepared products can maintain over 80% of the original fluorescence intensity even when it is immersed in water for 2 weeks. The CsPbBr 3 PQDs/MSs are utilized in the white light‐emitting diode device with Commission Internationale de L'Eclairage color coordinates of (0.3407, 0.3357) at 20 mA, and exhibit excellent photo stability at high power.