Preparation And Properties Of Lead Halide Perovskite-polyacrylate Gel Composites

Lead halide perovskite has become one of the most promising materials in the field of optoelectronic devices because of its excellent optical properties,such as band gap tunability,long carrier life,high photoluminescence quantum yield and narrow emission linewidth.However,lead halide perovskite materials are vulnerable to external factors due to their low formation energy and high fluidity ion structure with surface traps.With poor stability has become the main obstacle to the practical application of lead halide perovskite.Under the protection of polymer,the stability of perovskite-polymer composites has been greatly improved.At the same time,the addition of polymer also improves the mechanical properties of perovskite.Polymer gel has three-dimensional crosslinked polymer network,which can provide a more favorable protective matrix,offer better mechanical properties and is convenient for direct device preparation.In this study,two strategies for preparing perovskite-polymer gel composites were proposed and the properties of the composites were characterized.First,the composite material of CH₃NH₃PbBr₃-PBA gel was prepared by in-situ precipitation,which showed excellent water stability and no significant decrease in PL intensity after immersion in water for 15 days.The mechanical properties of the composites could be adjusted in a certain range（elongation300%-900%）by adjusting the amount of crosslinker.CH₃NH₃PbBr₃ NCs were uniformly distributed in the PBA gel matrix,and materials with different luminescence intensity could be prepared by adjusting the amount of NCs addition.Next,CH₃NH₃PbBr₃ was used as photocatalysts for PET-RAFT polymerization of acrylate monomers,and the effects of photocatalyst dosage and RAFT agent type on polymerization were investigated.The monomer conversion could reach more than 90%at a photocatalyst dosage of 0.05 wt%（compared to the monomer）and a blue light intensity of 6 m W/cm² for 2 h irradiation reaction.This study demonstrated the high efficiency of CH₃NH₃PbBr₃ as photocatalysts and provided theoretical support for the feasibility of the subsequent preparation of CH₃NH₃PbBr₃-polyacrylate gel composites by in-situ polymerization.Finally,the composites of CH₃NH₃PbBr₃-PBA gels and CH₃NH₃PbBr₃-PMA gels with good fluorescence properties were prepared by in-situ polymerization,and in this study CH₃NH₃PbBr₃ played both functions of photocatalytic and fluorescence properties.The composites could preserve fluorescence in air for more than 15 days,while the mechanical properties of the materials could be adjusted within a certain range by the amount of crosslinker.The method also exhibited unique oxygen resistance,which provides great convenience for the preparation of composites.