Synthesis and Luminescent Properties of Eu³⁺Doped Complex Borosilicate Glasses

Glasses with compositions 52.5B2O3:12.5SiO2:25La2O3:5CaO:5ZnO:0.5Eu2O3 and50B2O3:10SiO2:25La2O3:5CaO:5ZnO:5WO3:0.5Eu2O3 (mol%) were prepared by conventional melt-quenching method and investigated by X-ray diffraction analyses, DSC analysis, DR-UV-Vis spectroscopy and photoluminescence spectroscopy. Physical properties like density, molar volume, oxygen molar volume and oxygen packing density were also determined. Glasses are characterized with high glass transition temperature (over 650 °C). DR-UV-Vis spectroscopy results indicate that the tungstate ions incorporate into the base borosilicate glass as tetrahedral WO4 groups. The lower band gap energy values show that the introduction of WO3 into the base borosilicate glass increases the number of non-bridging oxygen species in the glass structure. The emission intensity of the Eu3+ ion increases with the introduction of WO3 due to the occurrence of non-radiative energy transfer from the tungstate groups to the active ion. The most intense luminescence peak observed at 612 nm suggest that the glasses are potential materials for red emission.