Luminescence properties of Dy3+-doped alkali lead alumino borosilicate glasses

A new series of Dy³⁺-doped sodium lead alumino borosilicate glasses are prepared by the melt quenching technique with the chemical composition 20Na₂O- 10PbO-(5-x)Al₂O₃-40B₂O₃–25SiO₂-xDy2O3 (where x?=?0, 0.5, 1.0 and 1.5?mol%) and are characterized by various spectroscopic techniques such as XRD, FT-IR, Optical absorption spectra, Fluorescence spectra and Decay measurements. Optical and Luminescence spectra of all the glasses are recorded at room temperature. From the optical absorption spectra, optical band gap and Urbach energies of Dy³⁺-doped titled glasses have been evaluated. The oscillator strengths and the intensity parameters, Ω_λ (λ?=?2, 4 and 6) are calculated using Judd-Ofelt analysis. The various lasing parameters like transition probability (A_T), branching ratio (β_R), stimulated emission cross-section (σ_e) and the radiative lifetime (τ_rad) for different emission levels of Dy³⁺ ions have been evaluated. Fluorescence spectra show sharp emission peaks are observed at 482?nm (blue), 575?nm (yellow) and 665 (red) under 385?nm excitation, which are attributed to ⁴F_9/2→⁶H_15/2, ⁶H_13/2 and ⁶H_11/2 transitions respectively. The yellow-to-blue intensity ratio (Y/B) increase up to 1.0?mol% Dy³⁺ ion content and beyond it decreases because of concentration quenching which occurs due to the energy transfer between Dy³⁺ and Dy³⁺ ions. The x, y coordinates of the prepared glasses pass through the white light region in the CIE 1931 chromaticity diagram. The results reveal that these glasses emit quality white light which is suitable for the development of W-LEDs. The color purity and the correlated color temperature (CCT) are also calculated for the present work. Various physical parameters such as density, refractive index, and ion concentration etc., are calculated. Among the prepared glasses, NPABSDy10 glass exhibits higher σ_e, β_R, σ_exτ_R, and σ_exΔλ_eff values corresponding to the ⁴F_9/2→⁶H_13/2 emission band and these are in turn specifies its suitability for W-LEDs and visible laser applications.