Highly efficient ultra-violet-stimulated green-emitting Tb3+ activated Sr6Y2Al4O15 nanocrystalline materials for advanced single-phase pc-WLED fabrication

Strong green-emission is observed in the new Tb³⁺ activated Sr₆Y₂Al₄O₁₅ nanocrystalline material series fabricated via solution combustion methodology. A monoclinic crystal framework with space group I4/mcm (140) having irregularly shaped grains with an average size of 49 nm is formed. Morphological aspects are examined via scanning and transmission electron microscopy (SEM and TEM). On near-UV excitation, the photoluminescence spectrum presents a fair green-light production at 18382 cm^-1 wavenumbers reliable with the ⁵D₄→⁷F₅ electronic transition. The energy transfer phenomena are also discussed. The highest luminous intensity is observed for 5.0 mol% of Tb³⁺ composition with 282 nm excitation wavelength. d-d exchanges authorized the presence of the concentration quenching phenomenon. Diffuse reflectance spectroscopy was taken into use to explore the energy band gap which lies in the semiconductor domain. The CIE coordinates lay in the greenish zone of the chromaticity scheme, thus confirming their latent contention in pc-WLED fabrication and other advanced photonic applications.

Graphical abstract

Strong green-emission is observed in the new Tb³⁺ activated Sr₆Y₂Al₄O₁₅ nanocrystalline material series fabricated via solution combustion methodology. A monoclinic crystal framework with space group I4/mcm (140) having irregularly shaped grains with an average size of 49 nm is formed. On near-UV excitation, the photoluminescence spectrum presents a fair green-light production at 18382 cm^-1 wavenumbers reliable with the ⁵D₄→⁷F₅ electronic transition. The CIE coordinates lay in the greenish zone of the chromaticity scheme, thus confirming their latent contention in pc-WLED fabrication and other advanced photonic applications.