In situ growth strategy to construct perovskite quantum dot@covalent organic framework composites with enhanced water stability

摘要

Metal halide perovskite quantum dots (QDs) have excellent optoelectronic properties; however, their poor stability under water or thermal conditions remains an obstacle to commercialization. Here, we used a carboxyl functional group (-COOH) to enhance the ability of a covalent organic framework (COF) to adsorb lead ions and grow CH3NH3PbBr3 (MAPbBr(3)) QDs in situ into a mesoporous carboxyl-functionalized COF to construct MAPbBr(3) QDs@COF core-shell-like composites to improve the stability of perovskites. Owing to the protection of the COF, the as-prepared composites exhibited enhanced water stability, and the characteristic fluorescence was maintained for more than 15 d. These MAPbBr(3) QDs@COF composites can be used to fabricate white light-emitting diodes with a color comparable to natural white emission. This work demonstrates the importance of functional groups for the in situ growth of perovskite QDs, and coating with a porous structure is an effective way to improve the stability of metal halide perovskites.