A Study of Structural, Optical and Photoluminescence Properties of Pr3+ Ions Doped Sodium Bismuth Borosilicate Glasses.

In this work, the conventional melt quenching approach is used to synthesize the Pr³⁺ doped NaF-Bi₂O₃-B₂O₃-SiO₂ (NBBS) glasses. The influence of Pr³⁺ ions on their spectroscopic and structural characteristics in glass network is investigated. The amorphous nature of the samples has been amply verified by X-ray diffraction patterns. FTIR spectra show distinct basic vibrational bands in borate and silicate structural components (in the range from 500 to 3750 cm^- 1). In the UV-visible range, the absorption spectra showed four Pr³⁺ ion absorption bands. Furthermore, in the absorption spectra, four Pr³⁺ ion absorption bands were observed in the NIR regions (1300-2470 nm). While utilizing Tauc plots to assess optical bandgap (Eg), it is observed that as the concentration of Pr³⁺ increases from 0 mol% to 1.5 mol%, the bandgap decreases from 3.67 eV to 3.50 eV. In luminescence spectra, seven bands can be observed at about 483, 524, 534, 580, 604, 643, and 682 nm as a consequence of Pr³⁺ ion transitions. Strong variations in the emission band's intensity are seen at around 604 nm (³P₀→³H₆), after a progressive increase in Pr mol% in the glass matrix. According to CIE coordinates, emission changes from orange to reddish-orange as the quantity of Pr³⁺ ions rises.