Effects of Eu2+ doping on the structure and luminescence properties of strontium borosilicate glasses

Abstract Eu2+-doped SiO2-SrO-B2O3 glasses (abbreviated as GE) were successfully prepared and the structure and luminescence properties were detailed investigated. The results show that the GE glass with 0.4 mol% Eu2+ has the most compact structure owing to its low molar volume, high density. The GE glasses exhibit broad luminescence band centered at approximately 469 nm and 0.4 mol% Eu2+ is the optimum doping concentration. The absorption and emission spectra show redshift as increasing Eu2+ concentration. The optical band gap decreases from 2.86 to 2.68 eV and the Urbach energy decreases from 0.2241 to 0.1737 eV. The 5d-4f transition of Eu2+ is an indirect electronic transition. Concentration quenching occurs with the increase of Eu2+ content and the mechanism is belong to the type of electric dipole-dipole interaction. The luminescence intensity decreases with increasing temperature and the thermal quenching activation energy is 0.26 eV. The chromaticity shift is lower than Eu2+-doped commercial phosphors.