Spectroscopic Analysis on Sm³⁺ Doped Fluoroborate Glasses

Abstract

Optical behaviors of the Sm³⁺ doped (50 − x) B₂O₃ + 25ZnO + 25NaF + xSm₂O₃, (where x = 0.05, 0.1, 1, 2 and 3 wt%) glasses have been studied and reported. The glasses were prepared by following melt-quenching technique and the optical absorption spectra in the UV-vis-NIR region between 350 and 1800 nm and the luminescence spectra between 550 and 750 nm, have been measured for the prepared glasses at room temperature. Optical band gap, band tail parameter, and Urbach energy have been calculated from the fundamental absorption edges for direct and indirect transitions. The band gap value is found to decrease with the increasing concentration of the Sm³⁺ ions. The band gap values are found to be 3.075–2.011 eV for direct transitions and 3.408–2.661 eV for indirect transitions. The origin of the Urbach energy has been identified and discussed. The Urbach energy is found to increase considerably with the increase in Sm³⁺ ions and is found to have values from 0.2268  to 0.8854 eV. A strong luminescence in the reddish-orange spectral region has been observed for the prepared Sm³⁺ glasses.