Optical properties of Eu^2＋-doped strontium borate glasses containing F-and Li^＋ ions

In this experiment, strontium borate glasses were prepared using the conventional quenching method in air atmosphere. Optical absorption, photoluminescence excitation and emission spectra, X-ray excited luminescence （XEL）, and luminescence decay curve of the as-prepared glasses were investigated at room temperature. The as-prepared glasses had two kinds of Eu ions, i.e., Eu^2＋ and Eu^2＋. Compared with the reported results of strontium borate glasses, Eu^2＋ luminescence was enhanced in the studied strontium borate glasses coprepared with F^- and Li^＋ ions. The coexisting of Li^＋ or F^- in the borate glasses could create more negative defect Vsr″ and stabilize Eu^2＋ ions, which might act as donor of electrons; For the F^- doping, the new center of B（O, F）4 （or BO3F） and BO2F2 units could be considered to be the distorted （BO4）, which were needed as a rigid framework to stabilize the divalent rare earth ions.