Photoluminescent multilayer films based on polyoxometalatesXRR spectrum of {(PEI/PSS/PAH)(EuP5W30/PAH)6}, UV-Vis spectrum of EuP5W30 anion and AFM image of the top layer of (PEI/PSS/PAH). See http://www.rsc.org/suppdata/jm/b1/b108283c/