A stable lead halide perovskite nanocrystals protected by PMMA

To enhance the stability in humidity is very crucial to hybrid organic-inorganic lead halide perovskites in a broad range of applications. This report describes a coating stratergy of perovskite nanocrystals via poly-methylmethacrylate-introduced ligand-assisted reprecipitation, using the interactions between the Pb cations on the surface of perovskite nanocrystals and the functional ester carbonyl groups in polymethylmethacrylate framework. The hydrophobic framework shields the open metal sites of hybrid organic-inorganic lead halide perovskites from being attacked by water, effectively retarding the diffusion of water into the perovskite nanocrystals. The as-prepared films demonstrate high resistance to heat and moisture. Additionally, the introduction of polymethylmethacrylate into ligand-assisted reprecipitation can effectively control the bulk precipitation and promote the stability of the perovskite solution.