Preparation Of Silica-Coated Perovskite Quantum Dots Powder

There are many strategies to maintain the excellent photoluminescence（PL）characteristics of perovskite quantum dots（QDs）.Encapsulating quantum dots（QDs）into other medium has been considered as an efficacious method to avoid the fluorescence degradation of QDs.Here,a facile method is proposed to embed CsPbBr₃perovskite QDs in silica matrix derived from（3-aminopropyl）triethoxysilane（APTES）at room temperature in open air.The QDs/SiO₂composite was extracted from the sol-gel solution by using a precipitation-encapsulation method assisted with APTES.As-prepared composite powder possess a high photoluminescence quantum yield（PLQY）of 68%and a full width at half maximum（FWHM）of～23 nm.A facile and effective method was proposed to prepare cyan Cs Pb（Cl/Br）₃/SiO₂powder at room temperature.Cubic Cs Pb（Cl/Br）₃was obtained by adding a Li Cl-H₂O solution and anion exchange reaction.The PLQY of the prepared cyan light quantum dot composite powder is as high as 84%,and considering that other types of cyan phosphors are inevitably plagued by defects such as low fluorescence efficiency,poor stability,and low color purity.The cyan Cs Pb（Cl/Br）₃/SiO₂phosphor with stability and excellent light and color characteristics does have great commercial potential and can play an important role in commercial full-spectrum display devices.CsPbBr₃QDs were first stabilized in amorphous SiO₂and crystalline hexagonal boron nitride（h-BN）nanosheets.The photoluminescence（PL）intensity of CsPbBr₃/SiO₂/h-BN nanohybrid only has a slight decrease than CsPbBr₃/SiO₂nanocomposite.But,dual protection of SiO₂and h-BN give perovskite QDs better humidity stability and thermal stability.Besides,CsPbBr₃/SiO₂/h-BN block exhibits excellent water-resistance.The preparation method provides a novel idea to fundamentally solve the intrinsic defects of perovskite QDs materials,thereby accelerating the practical application of QDs materials in optoelectronic devices.