Highly Efficient Red Emission from Novel Sm³⁺ Doped Na₃La(PO₄)₂ Nanophosphors for Optoelectronic Applications

Solution combustion procedure was used to create a succession of Na₃La_xSm_1 - x(PO₄)₂ (x = 0.01-0.15 mol) nanocrystals that generate a warm deep reddish light. Both HR-TEM and X-ray diffraction examinations were used to examine the morphology and crystalline phase analysis. Energy-dispersive X-ray analysis (EDAX) approves the elemental examination. The luminescence spectrum exhibits a decent reddish-orange emission at 700 nm wavelength upon near-UV illumination, which aligns with the electronic transition ⁴G_5/2 → ⁶H_11/2. According to Dexter's idea, nearest neighbor interlinkages are responsible for the concentration quenching that occurs after the Sm³⁺ ion composition reaches 6 mol%. Additionally, a detailed evaluation of the radiative lifespan (0.7519 ms), quantum efficiency (77%), Non radiative rate (307.40), color temperature (3170 K), color purity (99.2%) and color coordinates (0.652, 0.338) was conducted. The optical characteristics that have been observed indicate that Sm³⁺ doped Na₃La(PO₄)₂ phosphors could be a good option for improving WLED efficiency and color quality.