Self-assembly of lacunary Dawson type polyoxometalates and poly(allylamine hydrochloride) multilayer films: photoluminescent and electrochemical behavior

Ultrathin multilayer films containing a lacunary Dawson type polyoxometalate (POM) cluster K17[Ln(P2Mo17O61)2] (LnPMo, Ln = Eu, Tb) and poly(allylamine hydrochloride) have been prepared by electrostatic layer-by-layer self-assembly (ELSA) method. The multilayer films have been characterized by UV-vis absorption spectroscopy, ellipsometry and atomic force microscopy (AFM). The photoluminescent behavior of films at room temperature was investigated to show the Ln3+ characteristic emission pattern. The occurrence of photoluminescent activity confirms the potential applications in creating luminescent materials. Additionally, the electrochemical behavior of multilayer films was studied and the growth of multilayer films can be observed.