Luminescence of Phosphate Glasses: P2O5-ZnO-BaF2-K2TeO3-Al2O3-Nb2O5 Doped with Sm3+ Ions for Display and Laser Material

Abstract

Luminescent phosphate glasses having the composition 40P2O5-30ZnO-20BaF2-3.8K2TeO3-1.2Al2O3-5Nb2O5 in mol.% doped with 3 × 103 ppm and 4 × 103 ppm Sm2O3 were successfully prepared by a melt-quenching technique. The investigated glasses were characterized by x-ray diffraction, UV–visible–NIR, absorption, emission, and fluorescence lifetime analysis. The radiative properties were calculated using Judd–Ofelt (J–O) spectral intensity parameters for each of the glasses, which revealed the following trend: Ω2 > Ω4 > Ω6. The J–O intensity parameters were used to evaluate the spontaneous emission properties including branching ratios, transition probabilities, and radiative lifetime. The value of the optical energy band gap was found to decrease with an increase in Sm3+ content, which is explained on the basis of structural changes. The calculated stimulated emission cross-section $$ \sigma_{\rm{SE}} , $$ at 1.62 μm of glasses studied was high, and increased from 3.81 × 10−21 cm2 to 4.38 × 10−21 cm2 with increasing Sm3+ ion concentration. The structure of the glasses was investigated by computing $$ {\hbox{Internuclear }}\,\left( {r_{\rm{i}} } \right) $$ , Polaron radius $$ \left( {r_{\rm{p}} } \right) $$ and field strength $$ \left( F \right) $$ and measurement of Raman spectra.