Structural, UV light-excitable luminescence and warm white light generation of dysprosium ion-activated zinc leadfluoride sodium phosphate glasses

Multi-peak (blue–yellow–red) with warm white light generation of Dy³⁺ ions-activated zinc leadfluoride-based sodium phosphate (NPZ:60NaPO₃ + 25PbF₂ + 15ZnF₂) glasses were fabricated via the melt and rapid quenching method. The X-ray diffractogram and Raman spectra were studied to examine the amorphous and network structures of NPZDy glasses. The evaluated molar volume and density values increased with the rise in the amount of Dy³⁺ ions due to the formation of more non-bridging oxygen in the glass network. The result revealed that the Dy³⁺ ions-doped NPZDy glasses could absorb from 300 to 1800 nm wavelengths and then determined the bandgap energies of NPZDy glasses by using the Tauc’s plots. Upon 348 nm of ultraviolet radiation, the fabricated glasses emit red (665 nm), yellow (576 nm), and blue (482 nm) light from the ⁴F_9/2 → ⁶H_{11/2,13/2,15/2} transitions of Dy³⁺ ion. The influence of various molar fraction of Dy³⁺ ions on the Ω_2,4,6 and radiative properties of NPZDy glasses were studied by applying the Judd–Ofelt analysis. The decay times were evaluated by fitting the NPZDy glasses’ decays to the bi-exponential function. The larger gain bandwidth of 83.21 × 10^–28 cm³ and the maximum quantum efficiency of 79% for NPZDy glasses were calculated by the production of warm white light with (x, y) coordinates of (0.321, 0.361) and relative color temperature of < 4000 K.