New optical material europium EDTA complex in polyvinyl pyrrolidone films with fluorescence enhanced by silver plasmons

In our search for efficient Luminescent Solar Concentrators (LSC) we have prepared polyvinyl pyrrolidone (PVP) films incorporated by ethylenediamine tetraacetic acid (EDTA) complex of europium and co-doped with silver nanoparticles (NPs). Steady state fluorescence was studied under weak and strong excitation. Dynamical study was performed by second harmonic of Nd laser. Under weak excitation the fluorescence of europium co-doped with silver plasmons increased by a factor of three and excited by continuous laser by a factor of 50. The lifetimes of films doped by the complex were 755 mu s and co-doped with silver nanoparticles 946 mu s. This is the first finding that the photon density accumulates the number of plasmons interacting with electronic states of europium increasing its transition probability resulting in the strong intensification of fluorescence. In dynamical measurements of lifetimes a single pulse does not provide enough energy to create such number of plasmons. (C) 2011 Elsevier B.V. All rights reserved.