Sensitization and intra-molecular energy transfer of Eu3+ by Tb3+ in Eu-Tb binuclear complexes/PMMA

Abstract

A series of Eu 0.5 Tb 0.5 (TTA) 3 Phen/PMMA (TTA=thenoyltrifl uoroacetone, Phen=phenanthroline) and Eu 0.5 Tb 0.5 (TTA) 3 Dipy/PMMA (Dipy=2,2'-dipyridyl) were prepared by in-situ polymerization. The structures of the composites were characterized by IR spectra and electron spectrum. Photoluminescence properties were investigated by UV-Vis spectra and fl uorescence spectra. Meanwhile, the energy transfer models were set up. The results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent materials. Eu 0.5 Tb 0.5 (TTA) 3 Phen/PMMA and Eu 0.5 Tb 0.5 (TTA) 3 Dipy/PMMA emitted mostly characteristic fl uorescence of europium ion and intense red fl uorescence with peak wavelength at 611.8 nm and bandwidth of 10.4 nm under UV excitation at 365 nm. Fluorescence intensity of Eu 0.5 Tb 0.5 (TTA) 3 Phen/PMMA was found to be infl uenced with the content of MMA. The fl uorescence emission of europium ions was greatly sensitized by terbium ions and the enhancement of red emission was most likely due to the energy transfer enhancement from Tb 3+ to Eu 3+ .