Effect of BaF2 addition on luminescence properties of Er3+/Yb3+ co-doped phosphate glasses

Abstract

Er3+/Yb3+ co-doped phosphate glasses (P2O5-Al2O3-BaO-BaF2-K2O-Er2O3-Yb2O3) with varying BaF2 content, were prepared by a conventional melt quenching technique and their spectroscopic properties were examined through the Raman, absorption, emission and decay measurements. Raman spectra (350–1400 cm−1) of the Er3+/Yb3+ co-doped phosphate glasses with varying BaF2 content, were recorded upon laser excitation at 785 nm. Near infrared luminescence spectra were measured in the 1400–1600 nm region under 970 nm diode laser excitation and characteristic band was observed at 1533 nm corresponding to 4I13/2 → 4I15/2 transition of Er3+ ion. The decay curves for the 4I13/2 level of Er3+ ion, were measured and the lifetime is found to decrease from 7.94 to 7.70 ms when BaF2 content increases from 0 to 8 mol% and then increases up to 7.83 ms with further increase in BaF2 content (12 mol%). The emission cross-section, lifetime and figure of merit for the 4I13/2 → 4I15/2 transition of Er3+ ion were evaluated and compared to the other host matrices. The upconversion luminescence was measured and intense red emission was observed for all the studied samples.