Spectroscopic properties of trivalent europium and terbium ions in modificated polyethylene phthalate with aza-aromatic acids

Abstract

We have measured the emission spectra and lifetimes for Eu(III) and Tb(III) ions in polyethylene phthalate doped with some N-hetero-aromatics acids, which were pyrazine-2-carboxylic, pyridine-2-carboxylic, pyridine-3-carboxylic acids and amine-3-substituted acids. From the results we have found that pyrazine-2-carboxylic acid enhances both europium and terbium luminescence, while the other acids increase the polymer luminescence. This points out that these acids are less effective in transferring energy to Eu(III) and Tb(III) excited states than the first one.