Lead borophosphate zinc barium glass systems doped with different concentrations of Dy2O3 (0.5–2.0 mol%) were fabricated using the traditional melt-quenching method. The non-crystalline nature of the synthesized glass samples was verified through X-ray diffraction (XRD) analysis, which exhibited the characteristic absence of sharp diffraction peaks. Morphological, structural, and vibrational properties were analyzed using scanning electron microscopy (SEM) and Fourier infrared transmission (FTIR) spectroscopy. Optical absorption, emission, and decay lifetime observations were recorded to evaluate the luminescence behavior of Dy3+ ions. Judd–Ofelt parameters (Ω2, Ω4, and Ω6) were evaluated from the optical absorption spectra of all the prepared glass samples. The emission spectra revealed three dominant transitions in the visible region corresponding to the 4F9/2 ⟶ 6H15/2 (blue ~ 484 nm), 4F9/2 ⟶ 6H13/2 (yellow ~ 574 nm), and 4F9/2 ⟶ 6H11/2 (~663 nm) transitions. Radiative characteristics, including radiative transition probability (AR), radiative lifetime (τR), and branching ratio (βR), were calculated from the emission spectra. Among the investigated compositions, the host glass embedded with 1.0 mol% Dy2O3 demonstrated the maximum emission intensity was observed along with superior quantum efficiency (η = 91.68%). The chromaticity coordinates for this composition (x = 0.33, y = 0.41) are positioned close to the white-light region in the CIE 1931 chromaticity diagram. These findings suggest that incorporating 1.0 mol% of Dy2O3 yields the highest luminescence efficiency, making the present glass system a promising candidate for white-light-emitting and photonic device applications.
Kumar et al. (Sat,) studied this question.