Structure and Luminescence Properties of Novel Dy³⁺and Tb³⁺ Activated Ca₁₀(PO₄)₆Cl₂ Phosphors for Solid-State...

The novel Dy³⁺-and Tb³⁺-doped Ca₁₀(PO₄)₆Cl₂ phosphor is synthesized by the conventional wet chemical technique. The XRD pattern of prepared Dy³⁺ and Tb³⁺ doped in host material is in well agreement with the PDF card no. 7032212. The SEM image shows that the size of the particle is non-uniform in size and shape; it ranges in submicrometers. FTIR analysis confirms phosphate (PO₄)^3- and Ca-O group bonding present in Ca₁₀(PO₄)₆Cl₂ phosphor. The photoluminescence spectra of the prepared Ca₁₀(PO₄)₆Cl₂:Dy³⁺ phosphor, under the excitation at 350 nm, it exhibit two emission peaks located at 474 nm (⁴F_9/2 → ⁶H_15/2) and 572 nm (⁴F_9/2 → ⁶H_13/2), emitting blue and orange color respectively. The high-intensity peak is located at 474 nm. The PLE spectra of Ca₁₀(PO₄)₆Cl₂:Tb³⁺ phosphor contain two strong emission peaks centered at 470 (blue) nm and 543 (green) nm, these ascribed due to ⁵D₄ → ⁷F₆ & ⁵D₄ → ⁷F₅ transition of Tb³⁺ ions monitored at 354 and 379 nm excitation. The concentration quenching mechanism between the Dy³⁺-Dy³⁺ ions and Tb³⁺-Tb³⁺ ions is primarily attributed to dipole-dipole (d-d) interactions. The results suggest that Ca₁₀(PO₄)₆Cl₂:RE (RE = Dy³⁺, Tb³⁺) phosphor shows promise for use as a near-UV phosphor in solid-state lighting applications.