A photoactive complex based on europium(III) using the amino acid phenylalanine as ligand was prepared and characterized. The obtained europium(III)/phenylalanine complex presents an effective energy transfer from ligands to the rare earth center. The observed photoluminescent behavior for europium(III)/phenylalanine complex was similar to the well known europium(III)/acetyl-beta-acetonate hydrate. New photoactive polyamide thin films were prepared using polycaprolactam as host of these complexes. The structural characterizations of the films were studied through Rutherford backscattering (RBS), Fourier transform infrared (FTIR) and Raman spectroscopies. The polyamide films doped with the amino acid and acetyl-beta-acetonate rare earth complexes maintain the original photoluminescent behavior, narrow emission bands corresponding to transitions (5)D(0 ->) (7)F(0-4), which indicates that this polymer is an excellent host to these complexes. (C) 2011 Elsevier B.V. All rights reserved.