Effect of heat treatment on photoluminescence attributes of Sm${}^{3+}$ doped B${}_2$O${}_3$-Na${}_2$O-La${}_2$O${}_3$ glasses embedded with silver nanoparticles

The lanthanum sodium borate glass of composition xSm${}_2$O${}_3$-yAgCl-(80-x-y)B${}_2$O${}_3$-15 Na${}_2$O-5La${}_2$O${}_3$ (where x = 0.5 and y = 0.1 mol %) was prepared and heat treated at a constant temperature of 450 °C with different annealing schedules of 10, 20 and 30 h durations to enable the formation and growth of the Ag nanoparticles. Transmission electron microscope measurements revealed the existence of Ag nanoparticles in the examined glass specimen. The strong red emission was observed for ${}^4$G${}_{5/2}$ → ${}^6$H${}_{7/2}$ inherent transition of samarium ions in the titled glass samples. The robust emission and excitation intensities of Sm${}^{3+}$ ions are at 10 h annealing durations, and then decrease with increasing annealing durations due to the quenching effect. The transition and radiative properties of various excited levels of Sm${}^{3+}$ in the titled glass series were estimated, including the branching ratios, stimulated emission cross-section, radiative lifetime, and radiative transition probabilities. The improved luminescence results and better JO features for the ${}^4$G${}_{5/2}$ → ${}^6$H${}_{7/2}$ emission transition suggest the glass specimens routed with Ag nanoparticles are beneficial for optoelectronic and photonic applications.