Effect of Bi2O3 on Physical and Luminescence Properties of Unconventional Bi/Er Co-Doped Sb2O3-WO3-Li2O Glasses

Abstract

New glasses in the system (80-x) Sb2O3-10WO3-10Li2O co-doped with Bi3+/Er3+ were synthesized using the melt quenching method. The Er3+ concentration was kept constant at 0.25 (mol. %) and the Bi2O3 content takes the values 0.5, 1, 1.5 and 2 (mol. %) in order to elucidate the effect of the Bi2O3 concentration on the measured physical and optical properties of the glasses studied. The pulse echo method of the propagation of ultrasound in these glasses has been used to determine the elastic modules (E, G, K and L) and Poisson ratio. The introduction of Bi2O3 in these glasses increases the thermal stability factor of the glass from 152 to 183°C with an increase in Tg from 275 to 285°C. The UV-Vis cutoff of these glasses redshifts from 408 to 413 nm with a reduction of the indirect band gap from 2.72 to 2.62 ev and a small Urbach energy close to 0.125 nm resulting in small electronic defects in these glasses. The refraction index was found high with small variations in the range [1.965-1.975]. The emission spectra of Er3+ ions in these glasses gave an intense green laser line at 544 nm for an excitation at 488 nm. Moreover, the addition of more Bi2O3, considerably improves this laser line. However, the OH content in these glasses increases with the increase in Bismuth content related probably to the introduction of atmosphere moisture during the synthesis of these glasses. Therefore, the addition of Bi2O3 improves the various physical properties of these glasses making them good candidates for optical applications.