Dy3+ ion as optical probe to study the luminescence behavior of Alkali lead bismuth borate glasses for w-LED application

Highlights: • Dysprosium doped alkali lead bismuth borate glasses were prepared. • Under 387 nm, the glasses exhibit intense yellow and blue emission. • Calculated CIE coordinates fall in yellowish white region of visible spectrum. • Lifetime decay from ⁴F_9/2 excited state found to display non-exponential behavior. -- Abstract: A series of different modifiers infused Dy³⁺ ions doped Alkali lead bismuth borate glasses were synthesized and their potential for photonic applications were analyzed through some mandatory characterizations like XRD, FTIR, Raman, optical absorption, photoluminescence and decay measurements. In this work, effort was taken to show the structural differences that occur in the host network when different modifiers were introduced into it. Amorphous nature of all the glasses was proven with XRD profile and the absorption of Dy³⁺ ions to different excited states was observed. The Judd-Ofelt (JO) parameters for the glasses follows the trend as Ω₂> Ω₄> Ω₆ and from the luminescence spectra, emissions corresponding to blue (⁴F_9/2→ ⁶H_15/2), yellow (⁴F_9/2→⁶H_13/2) and red (⁴F_9/2→⁶H_11/2) color were observed while exciting the prepared glasses at 387 nm. Radiative parameters like transition probability, stimulated emission cross-section, branching ratios and radiative lifetime were calculated using JO parameters and refractive index values. Yellow to blue intensity ratio (Y/B), CIE chromaticity coordinates and correlated color temperature (CCT) values are calculated using the emission spectra to evaluate the emitted light. The obtained CIE values were found to be in excellent proximity with the standard white light (0.33, 0.33). The lifetime of the ⁴F_9/2 excited state was measured and found to exhibit non-exponential behavior. The obtained results suggest the utility of the glasses for potential w-LED applications.