Influence of morphology on luminescence properties of xenotime-type phosphors NaYP₂O₇:Eu³⁺ synthesized via solid state and citrate-gel routes

A series of Eu³⁺ activated xenotime type rare earth phosphate NaYP₂O₇ based orange–red emitting phosphors have been prepared via solid state (SS) and citrate gel (CG) methods. The morphological variation of the developed phosphors concerning synthesis method and heat treatment has significantly influenced the luminescence properties. The phosphors synthesized by the CG route reveals the formation of homogeneous powder with small particles along with uniform size. The developed phosphors exhibit intense orange–red emission under 394 nm near UV excitation with a full width half maximum ~ 2 nm. Compared with the phosphors synthesized by SS route, the phosphors obtained by CG method possess enhanced and sharper orange–red emission with longer lifetimes due to the ⁵D₀–⁷F_1–2 transitions. The developed narrow red emitting phosphors have better emission intensity in comparison with commercially available Y₂O₃:Eu³⁺ red phosphors. Thus, these phosphors could be a suitable candidate for solid state lighting applications for the fabrication of white light emitting diodes.