Cross-linked polymer modified layered double hydroxide nanosheet stabilized CsPbBr3 perovskite quantum dots for white light-emitting diode

Abstract

Metal halide perovskite quantum dot (PQD) has received high attention from researchers owing to their excellent optical properties and broad application prospects in the past few years. However, the disadvantages of poor stability and low synthesis yield severely limit the further applications. Therefore, we developed an effective strategy to ameliorate the optical performance and environmental stability of PQD. Herein, a reversible addition-fragmentation chain transfer (RAFT) polymerization was applied to graft hydrophobic polymer chains on the surface of LDH nanosheets, and a cross-linked polymer network functionalized LDH (LDH-CP) was obtained through a quaternized reaction. Subsequently, LDH-CP-CsPbBr3 hybrid material was prepared by growing PQD on the surface of LDH-CPs by a simple ligand-assisted co-precipitation (LARP) technique. The synthesized hybrid material exhibited bright green luminescence with a narrow FWHM (~25 nm) and a high solid photoluminescence quantum yield (PLQY) (~51.9%). With the help of dual protection of the unique two-dimensional (2D) LDH nanosheets and the hydrophobic polymer cross-linked network, the nanohybrid displayed excellent water stability, thermal stability, and photostability. In addition, the white lighting-emitting diode (WLED) based on the LDH-CP-CsPbBr3 hybrid material also emerges with great white light emission and excellent device performance, proving that the hybrid material has great development potential in lighting and display applications.