Photoluminescence Explorations of Mg-Activated Potassium Phospho-Borate Glasses Doped With Dy3+ Ions for Laser Applications.

To scrutinise the spectroscopic performance of the Mg-activated potassium phospho-borate glasses doped with Dy3+ ions, a novel series of alkali/transition metals and heavy-metal modified glasses have been fabricated utilising the conventional melt-quench process. The nephelauxetic ratio (1<) and negative bonding parameter (δ) confirms that Dy-O bonds are ionic. The photoluminescence spectra show emission in the visible region is dominated by the electric-dipole 4F9/2 → 6H13/2 transition (~573 nm). The estimated JO parameters have the trend as Ω2 > Ω6 > Ω4, which indicates the asymmetric environment around the Dy3+. Exceptionally, the BPMKD:P glass follows the Ω2 > Ω4 > Ω6 trend. CIE analysis affirmed that the studied glass samples exhibit emission in the white region, with CdO and ZnO modified glass showing colour purity as 5% and 8%, respectively, which indicates its closeness to the pure-white light emission. Radiative parameters such as A, βR, σE, Δλeff and τrad were computed for the 6H15/2 → 6F15/2 and 6H15/2 → 6F13/2 transitions. Among all glasses, BPMKD:Z glass shows enhanced magnitudes of the radiative parameters, which demonstrate superior potential for lasing and opto-electronic applications. The decay profiles of the 4F9/2 level showed bi-exponential behaviour, wherein the higher quantum efficiency is found for the BPMKD:Z glass, which further confirms its suitability for white-light emitting applications.