Optimizing the highly efficient cool-white luminescence via modulating Dy³⁺ ion into novel Sr₆Al₄Y₂O₁₅ nanocrystals for white LEDs

Abstract

In the present prospective study, a variety of novel rare-earth Dy³⁺ singly activated Sr₆Al₄Y₂O₁₅ nanoscaled materials were fabricated through ecologically-sound as well as low-temperature facilitated urea-fueled combustion methodology. Monoclinic crystalline phase was recognized via the Rietveld analysis of X-ray powder diffraction (XRPD)-patterns. The metal–oxygen bonding pertaining in the studied sample was traced by the Fourier-transform infra-red (FT-IR) measurements. Energy dispersive spectroscopic (EDS) technology was used for the stoichiometric element distribution studies onto the present materials. The photoluminescent spectra (PL) recorded for fabricated powders, were primarily composed of two major bands viz. golden and bluish band centered at 579 and 485 nm, in the spectral regime. Luminance performance of present luminous materials was maximal at Dy³⁺ ion-content of x = 0.05; at which fluorescent decay-time (= 0.6701 ± 0.0056 ms), chromatic coordinates (x = 0.2865, y = 0.3312) and correlated color-temperature (CCT) value of 8089 K were determined. Quantum efficiency as well as color-purity of the Sr₆Al₄Y_1.90Dy_0.10O₁₅ powders were obtained as 90.46% and 19.86 × 10^–2, respectively. Attenuation of luminescence via exchange-kind inter-relations amidst Dy³⁺ ions, was assayed through Inokuti–Hirayama (I–H) model as well as Dexter’s formalization. Aforementioned outcomes, thereby, recommend the potential materialization of as-fabricated powder materials for near ultra-violet-stimulated white light-emanating diodes, luminance sensors, medical-diagnostics, biochemical probes and laser industry. Moreover, this research paper would provide a reference to conduct research into new such white-emanating aluminate-based phosphor materials.