Judd‐Ofelt analysis and optical properties of Eu³⁺‐doped GdPO₄ phosphors synthesized by combustion method

AbstractThe Eu3+‐doped GdPO4 nanoparticles were prepared via a straightforward combustion method using urea as fuel and nitrates as a precursor. X‐ray powder diffraction patterns, infrared spectrum (IR), HR‐TEM, photoluminescence (PL), phonon sideband and photoluminescence excitation (PLE) were researched. There is a phase transition from the hexagonal phase into the monoclinic phase when the calcined temperature is over 700 °C. All of phosphors have similar morphology and the average diameters for nanoparticles are 20–30 nm. Under the excitation at 273 nm, GdPO4:Eu3+ powders showed red emission bands originating from the 5D0–7FJ (J = 1, 2, 3 and 4) transitions of Eu3+. The orange‐red emission (5D0–7F1 transition) is dominated because the Eu3+ ions exist with inversion symmetry in the lattice. The study suggests that the optimal Eu3+ ions concentration is 5 mol%. In addition, the second order crystal field parameter (B20) and the influence of concentration of Eu3+ ions on decay time are also mentioned, the intensity parameters (Ω2,4,6) and quantum efficiency were determined based on Judd‐Ofelt theory.