Na 5 La(MoO 4 ) 4 : Dy 3+ phosphor: synthesis, structural, morphological and optical properties for applications in opto-electronic devices

Dy3+-doped molybdate phosphors have emerged as promising materials for wLEDs on account of their excellent thermal stability and extraordinary light emission properties. A series of xDy3 + doped Na₅La(MoO4)4 (where x = 0.5,1,3 & 5 mol.%) phosphors was synthesised using a conventional solid-state route and evaluated for their structural and optical properties due to their thermal and chemical stabilities. The phase purity, crystallinity and tetragonal structure having space group I4₁/a(88) were confirmed using XRD analysis, and the morphology was studied using SEM and confirmed particle size in the micrometre range. Photoluminescence (PL) studies revealed the blue and yellow emissions under near-UV excitation, ascribed to the 478 and 487 nm (⁴F9/2 → ⁶H15/2) and 576 nm (⁴F9/2 → ⁶H13/2) transitions of Dy³+ ions, respectively. The optimal doping concentration and chromaticity coordinates (x = 0.36 and y = 0.41) suggest that this phosphor can be used in wLEDs and other optical applications.