Luminescent inorganic–organic hybrid films based on europium-substituted heteropolymolybdate and poly(amidoamine) dendrimer

Multilayer films consisting of poly(amidoamine) (PAMAM) dendrimer and europium-substituted heteropolymolybdate K17[Eu(P2Mo17O61)2] (simplified as Eu(P2Mo17)2) were prepared by layer-by-layer (LBL) self-assembly and characterized by UV–vis measurements, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). UV–vis showed that the characteristic absorbance values of the multilayer films increased linearly with the layer numbers of Eu(P2Mo17)2/PAMAM films. The electrostatic interaction between Eu(P2Mo17)2 and PAMAM was demonstrated by XPS. In addition, AFM provided the surface morphology of Eu(P2Mo17)2/PAMAM films, revealing that the films contained well-defined Eu(P2Mo17)2 nanoparticles. The luminescence behavior of the films at room temperature was also investigated. The films exhibited the characteristic emission bands of Eu3+ and the fluorescence lifetime of Eu3+ in the films is shorter than that in the solid.