High refractive index of Eu3+ doped La2O3-TiO2-Nb2O5-WO3 oxide glasses with low wavelength dispersion

Eu ³⁺-doped La ₂O ₃-TiO ₂-Nb ₂O ₅-WO ₃ glasses with high refractive index ( n_d >2.20) and low wavelength dispersion ( ν_d >29) were successfully fabricated by containerless solidification. The amorphous nature is confirmed by XRD, HRTEM and corresponding electron diffraction. Both the Vicker′s hardness and thermal stabilities can be augmented by Eu ³⁺. The glass-forming ability measured using the temperature gap Δ T is found to be less than 63 °C. Excitated at 393 nm, these photonic glasses exhibit the strongest ⁵D ₀→ ⁷F ₂ red emission at 615 nm. A concentration quenching effect has been observed after the optimized concentration of x = 2. The effect of electron beam irradiation on the structural, transmittance in IR region, luminescence properties were also investigated. The results show that Eu ³⁺-doped La ₂O ₃-TiO ₂-Nb ₂O ₅-WO ₃ glasses can be used as a red-emitting component potentially applicable to near UV-based white LEDs, or as optical material applicable to optical devices such as smart phones with digital cameras and endoscopes.