Fluorescence and optical properties of Eu3+-doped borate glasses

The glasses with chemical composition of 25Na2O:23CaO:6P2O5:44B2O3:2ZrO2: xEu2O3 for extra different Eu2O3 concentrations of x = 0.25, 0.5, 0.75, 1.0 and 1.25 mol% were synthesized by the conventional melt quenching technique. The glass structure, physical property, optical and luminescence characteristics of the synthesized glasses were characterized by FT-IR spectroscopy, X-ray powder diffraction and photoluminescence (PL) spectra, respectively. The results indicated that the density and molar volume of the glasses were found to increase with Eu2O3 concentration. The glasses were composed of [PO4], [BO3] and [BO4] basic structural units. Under 393 nm wavelength excitation, five luminescence bands were observed at 578 nm, 592 nm, 612 nm, 653 nm and 701 nm, which corresponds to 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions. And the most intense red emission was found at 612 nm. Moreover, the color coordinate and color correlated temperatures (CCTs) changed with Eu2O3 contents. This work shows the potential application of europium-doped glass samples in UV converted white light-emitting diodes (WLEDs) and other optical devices.