Gadolinium-based Sm3+ activated GdSr2AlO5 nanophosphor: synthesis, crystallographic and opto-electronic analysis for warm wLEDs

Abstract

A material's luminosity characteristics, which in turn dictate its applicability, are critically influenced by its structure. Therefore, it is essential for design and fabrication of optical nanocrystalline materials to comprehend the relationship between structural and luminescence properties. The gel-combustion approach was used to produce a sequence of orange–red light emanating GdSr₂AlO₅:Sm³⁺ (GSA:Sm³⁺) nanophosphors which are used for warm white-light-emitting diodes (w-LEDs). Comprehensive investigation of the structural and optical characteristics of GdSr₂AlO₅:Sm³⁺ nanophosphors has been done in a detailed manner. The synthesized powdered nanophosphors are crystallized in a tetragonal phase with I4/mcm (140) space group, affirmed through Rietveld refining method. The nano size with an aggregated, spherical form of the particles in the powdered nanocrystalline material was revealed by TEM analysis. These orange–red emitting phosphors Gd_1−xSr₂AlO₅:xSm³⁺ (x = 1–7 mol%) were shown to possess photoluminosity (PL) properties that demonstrated the presence of most intense emission peaks at 603 nm that were caused by ⁴G_5/2 → ⁶H_7/2 transitions of the Sm³⁺ ion under 273 nm excitation. Considering its long decay lifespan and PL emission, it can be concluded that the GdSr₂AlO₅:Sm³⁺ phosphor is a potential single element for the fabrication of warm white light-emitting devices.