Structural and spectroscopic investigations on Eu3+-ions doped Na2O/NaF-Al2O3-P2O5 glass

Na ₂O-Al ₂O ₃-P ₂O ₅: Eu ₂O ₃ and NaF-Al ₂O ₃-P ₂O ₅: Eu ₂O ₃ were synthesized using conventional melt-quenching technique. Characterization techniques including FTIR, UV–Vis-NIR and photoluminescence spectroscopy were used to investigate the structural, optical and luminescence properties of Eu ³⁺-ions. The obtained trend for JO-parameters shows that as compared to Na ₂O-Eu glass, NaF-Eu glass has more asymmetric environment around Eu ³⁺ -ions and less degree of covalency between ligands (oxygen) and Eu ³⁺ -ions. The evaluated phonon energy is 1225 cm ^-1 for Na ₂O-Eu glass and 1274 cm ^-1 for NaF-Eu glass. NaF-Eu has higher value of σ (λ _P) and β _R for ⁵D ₀→ ⁷F ₂ transition as compared to Na ₂O-Eu, thus more suitable to be used as laser applications. The CIE-color coordinates (x, y) for Na ₂ O-Eu and NaF-Eu glasses are (0.65, 0.35) and (0.65, 0.34) respectively. Whereas, quantum efficiency (η) for the prepared Na ₂O-Eu glass is 57 % and of NaF-Eu glass is 64 %. The CIE color coordinates of NaF-Eu fall within the reddish-orange region, making it promising material for use in optical display devices.