Blue photons excited highly chromatic red light emitting K3La(PO4)2:Pr3+ phosphors for white light emitting diodes

Highlights: • K₃La(PO₄)₂:Pr³⁺ phosphors were investigated as an alternative for red light. • Highly chromatic red emission was realized upon blue excitation. • The phosphor has high color purity ∼ 97.8% and yield ∼27%. - Abstract: Highly chromatic blue photons excited red emitting K₃La(PO₄)₂:Pr³⁺ (0–1.8 mol%) phosphors were synthesized by solution combustion method. The resulted phosphors showed peanut like morphology and had a monoclinic phase with space group P2₁/m. The photoluminescence studies disclosed that the phosphor emits red light due to the ¹D₂ → ³H₄ and ¹D₂ → ³H₅ transition of the Pr³⁺ ions under blue photons excitation. The optimal concentration for the Pr³⁺ ions were optimized to be 1.2 mol% after which concentration quenching occurred. Dipole-dipole interaction among the dopant ions was found to be responsible for the concentration quenching. X-ray photoelectron spectroscopy results depicted that Pr was present in the (+3) valance state in the phosphor. The photometric results suggest that the phosphor with a high color purity ∼ 97.8% and enough quantum yield ∼27% could be an eventual choice as the red component for white light emitting diodes.