Study on photoluminescence properties of oxyfluoride germanate Glass

The oxyfluoride germanate glass and glass-ceramics were prepared by the melting–annealing method. The composition of the glass was chosen as 45GeO2–30BaF2–5B2O3–15AL2O3–5R2O–xSm2O3 (R = Li, Na, and K. x = 1.5, 2.0, and 2.5, mol%). Differential thermal analysis, X-ray diffraction, and photoluminescence spectra were carried out to study the effects of the concentration of Sm ions, the kinds of alkali ions and heat treatment on the photoluminescence properties of Sm ion doped oxyfluoride germanate glass. The results showed that the luminescence intensity of the oxyfluoride germanate glass increased when x changed from 1.5 to 2.0 and then decreased when x changed from 2.0 to 2.5. Among various R2O, the Li2O included glass has the strongest luminescence intensity among all the glasses. Heat treatment at 660 °C for 4 h resulted in the formation of the Ba3AlF9 nanocrystal and enhanced the luminescence intensity of the sample. The mechanism of luminescence intensity increase was discussed.