The effect of the addition of Nb₂O₅ (up to 5 mol%) on the structure and luminescent properties of ZnO-B₂O₃ glass doped with 0.5 mol% (1.32 × 10²²) Eu₂O₃ was investigated by applying infrared (IR), Raman and photoluminescence (PL) spectroscopy. Through differential thermal analysis and density measurements, various physical properties such as molar volume, oxygen packing density and glass transition temperature were determined. IR and Raman spectra revealed that niobium ions enter into the base zinc borate glass structure as NbO₄ tetrahedra and NbO₆ octahedra. A strong red emission from the ⁵D₀ level of Eu³⁺ ions was registered under near UV (392 nm) excitation using the ⁷F₀ → ⁵L₆ transition of Eu³⁺. The integrated fluorescence intensity ratio R (⁵D₀ → ⁷F₂/⁵D₀ → ⁷F₁) was calculated to estimate the degree of asymmetry around the active ion, suggesting a location of Eu³⁺ in non-centrosymmetric sites. The higher Eu³⁺ luminescence emission observed in zinc borate glasses containing 1–5 mol% Nb₂O₅ compared to the Nb₂O₅-free zinc borate glass evidences that Nb₂O₅ is an appropriate component for modifying the host glass structure and improving the emission intensity.

Glasses with the compositions in mol % of 50ZnO:(50 − x)B₂O₃:0.5Eu₂O₃:xWO₃, x = 0, 1, 3, 5 and 10 were obtained by applying the melt-quenching method and investigated by Raman spectroscopy, DSC analysis and photoluminescence (PL) spectroscopy. Raman spectra revealed that tungstate ions incorporate into the base zinc borate glass as tetrahedral [WO₄]²⁻ groups, and octahedral [WØ₄O₂]²⁻ species with four bridging and two non-bridging oxygen atoms. There are also metaborate, [BØ₂O]⁻ and pyroborate units, [B₂O₅]⁴⁻, in the glass networks. The glasses are characterized by good transmission in the visible region, at about 80%. Photoluminescence (PL) spectra evidenced that WO₃ is an appropriate constituent for the modification of zinc borate glass structure and for enhancing the Eu³⁺ luminescent intensity. The most intense luminescence peak observed, at 612 nm, suggests that the glasses are potential materials for red emission.

Novel multicomponent glasses with nominal compositions of (50−x)MoO₃:xWO₃:25La₂O₃:25B₂O₃, x = 0, 10, 20, 30, 40, 50 mol% doped with 3 mol % Eu₂O₃ were prepared using a conventional melt-quenching method. Their structure, thermal behavior and luminescent properties were investigated by Raman spectroscopy, differential thermal analysis and photoluminescence spectroscopy. The optical properties of the glasses were investigated by UV–vis absorption spectroscopy and a determination of the refractive index. Physical parameters such as density, molar volume, oxygen molar volume and oxygen packing density were determined. The glasses are characterized by a high glass transition temperature. Raman analysis revealed that the glass structure is built up mainly from tetrahedral (MoO₄)²⁻ and (WO₄)²⁻ units providing Raman bands of around 317 cm⁻¹, 341–352 cm⁻¹, 832–820 cm⁻¹ and 928–935 cm⁻¹. At the same time, with the replacement of MoO₃ with WO₃ some fraction of WO₆ octahedra are produced, the number of which increases with the increasing WO₃ content. A strong red emission from the ⁵D₀ level of Eu³⁺ ions was registered under near-UV (397 nm) excitation using the ⁷F₀ → ⁵L₆ transition of Eu³⁺. Photoluminescence (PL) emission gradually increases with increasing WO₃ content, evidencing that WO₃ is a more appropriate component than MoO₃. The integrated fluorescence intensity ratio R (⁵D₀ → ⁷F₂/⁵D₀ → ⁷F₁) was calculated to estimate the degree of asymmetry around the active ion, suggesting a location of Eu³⁺ in non-centrosymmetric sites. All findings suggest that the investigated glasses are potential candidates for red light-emitting phosphors.

In this study, we investigated the influence of Bi₂O₃ and WO₃ on both structure and optical properties of 50ZnO:(49 − x)B₂O₃:1Bi₂O₃:xWO₃; x = 1, 5, 10 glasses doped with 0.5 mol% Eu₂O₃. IR spectroscopy revealed the presence of trigonal BØ₃ units connecting superstructural groups, [BØ₂O]⁻ metaborate groups, tetrahedral BØ₄⁻ units in superstructural groupings (Ø = bridging oxygen atom), borate triangles with nonbridging oxygen atoms, [WO₄]²⁻ tetrahedral, and octahedral WO₆ species. Neutron diffraction experimental data were simulated by reverse Monte Carlo modeling. The atomic distances and coordination numbers were established, confirming the short-range order found by IR spectra. The synthesized glasses were characterized by red emission at 612 nm. All findings suggest that Eu³⁺ doped zinc borate glasses containing both WO₃ and Bi₂O₃ have the potential to serve as a substitute for red phosphor with high color purity.

In this study we have investigated the effect of the addition of Nb2O5 (up to 5 mol%) on the structure and luminescent properties of ZnO-B2O3 glass doped with 0.5 mol % Eu2O3 by using of infrared (IR), Raman and photoluminescence (PL) spectroscopy. Physical properties as molar volume, oxygen packing density and glass transition temperature were determined using the results of differential thermal analyisis (DTA) and Archimedes principle for density. IR and Raman spectra revealed that niobium ions incorporate into the base zinc borate glass as NbO4 trtraherda and NbO6 octahedra. A strong red emission from the 5D0 level of Eu3+ ions was registered under near UV (392 nm) excitation using the sharp 7F0 - 5L6 transition of Eu3+. The integrated fluorescence intensity ratio R (5D0 → 7F2/5D0 → 7F1) was calculated to estimate the degree of asymmetry around the active ion, suggesting a location of Eu3+ in non-centrosymmetric sites. The higher Еu3+ luminescence emission observed in zinc borate glasses containing 1÷5 mol% Nb2O5 compared to the Nb2O5-free zinc borate glass evidences that Nb2O5 is suitable component for modification of host glass structure and improving the emission intensity.