The Physical, Optical, Photo and Radioluminescence Studies of Dy³⁺ Doped Zinc Barium Gadolinium Phosphate Glasses

Abstract: The Dy₂O₃ doped phosphate glasses of chemical composition 10ZnO · 10BaO · 10Gd₂O₃ · 70P₂O₅, 10ZnO · 10BaO · 10Gd₂O₃ · 69P₂O₅ · 1Dy₂O₃ and 10ZnO · 10BaO · 10GdF₃ · 69P₂O₅ · 1Dy₂O₃ were prepared by melt quench technique. The prepared glass samples were characterized through physical and luminescence properties such as density, molar volume, refractive index, FTIR, UV-Vis-NIR absorption spectra, photoluminescence excitation and emissions, radio-luminescence and life time. The J–O theory were analyzed to calculate the radiative properties such as radiative transition probabilities (A_R), stimulated emission cross section (σ_R) and branching ratio (β_R). Total nine characteristics absorption peaks belong to Dy³⁺ ion at the 347, 386, 454, 750, 800, 896, 1089 and1674 nm respectively corresponding to transition from ground state ⁶H_15/2 to excited state ⁴M_15/2+⁴I_15/2, ⁴F_7/2+⁴I_13/2, ⁴I_15/2, ⁶F_3/2, ⁶F_5/2, ⁶F_7/2, ⁶F_9/2 and ⁶H_11/2 are observed in absorption spectra in the 300–1900 nm region. The photoluminescence and radio-luminescence emission spectra of the present glasses were recorded and found in good agreement with one another. The CIE 1931 chromaticity color coordinates were evaluated and it is found that these coordinates positioned in the white region with (x, y) = (0.39, 0.44) values for both oxide and oxyfluoride glasses. The florescence decay time from ⁴F_9/2 level was measured by monitoring the intense ⁴F_9/2 → ⁶H_13/2 (573 nm) transition. The decay time is found to be non-exponential so the non-exponential curve was well fitted to Inokuti–Hirayama (IH) model for S = 6. The results obtained in present work demonstrate that the present glasses could be a good choice for use in white light solid state lighting applications.