Abbas J.Zaman F.Khan A.Saqib N.U.Rooh G.Choodam K.Kanjanaboos P.Intachai N.Kothan S.Albargi H.B.Kiwsakunkran N.Ali S.Chanthima N.Kaewkhao J.Mahidol University2025-07-222025-07-222025-10-01Optical Materials Vol.167 (2025)09253467https://repository.li.mahidol.ac.th/handle/123456789/111330Rare-earth doped phosphate glasses have emerged as promising materials for LED-based lighting applications due to their excellent thermal stability, high optical transparency, and efficient luminescent properties. In the current study, 15K<inf>2</inf>O: 20Al<inf>2</inf>O<inf>3</inf>: (65-x)P<inf>2</inf>O<inf>5</inf>: xDy<inf>2</inf>O<inf>3</inf>, herein (x = 0.0, 0.1, 0.3, 0.5, 1.0, 2.0 mol%) nominal composition was fabricated by solid-state method. The impact of Dy³⁺ ion on glass physical, optical, and luminescent features was evaluated using various characterization techniques such as XRD, FTIR spectroscopy, UV-viz-NIR spectra, J-O analysis, photoluminescence (PL) spectra, radio-luminescence (RL) spectra, decay analysis and CIE chromaticity. The density and refractive index increases with the rise in concentrations of Dy³⁺ ions. The non-crystallinity of KAPDy glasses has been confirmed using the X-ray diffraction technique. The Fourier Transform Infrared (FTIR) analysis shows that the structural characteristics of glasses with vibrational and stretching groups of different phosphate groups. The absorption spectra revealed nine bands with a hypersensitive band identified at the ⁶H<inf>15/2</inf> → ⁶F<inf>11/2</inf> + ⁶H<inf>9/2</inf> transition associated with 1280 nm. The excitation spectra detected eleven bands with the most intense band analogous to transition ⁶H<inf>15/2</inf> → ⁶P<inf>7/2</inf> at 350 nm. The fluorescence spectra obtained under λ<inf>exc</inf> = 350 detected 4 transitions equivalent to ⁴F<inf>9/2</inf> → ⁶H<inf>15/2</inf>, ⁴F<inf>9/2</inf> → ⁶H<inf>13/2</inf>, ⁴F<inf>9/2</inf> → ⁶H<inf>11/2</inf>, and ⁴F<inf>9/2</inf> → ⁶H<inf>9/2</inf>. A satisfactory agreement was discovered between the emissions spectra and the RL spectra. The trend Ω<inf>2</inf> > Ω<inf>6</inf> > Ω<inf>4</inf> in J−O parameters indicates that Dy³⁺ ions are placed in asymmetric positions and have strong covalent bonds with oxygen ligands. The study reveals that the experimental lifetimes (τ<inf>exp</inf>) fall with an increase in Dy³⁺ ions. CIE color coordinates were calculated to be x = 0.3853 and y = 0.4297. The CCT of the glass in hand was evaluated to be 4192 K which is suitable for usage in visible cool white LEDs. The highest value of quantum yield (QY) of the under-studied glasses was revealed to be 51.39 %. The results of these experiments point to possible uses for the glasses under study in the cool w-LED and laser domains.Materials ScienceChemistryPhysics and AstronomyEngineeringArticleSCOPUS10.1016/j.optmat.2025.1173112-s2.0-105010560987