Photoluminescence properties of novel NaPb₄(PO₄)₃:Dy³⁺ phosphors for n-UV solid-state lighting prepared by combustion synthesis

A series of NaPb₄(PO₄)₃:Dy³⁺ phosphors were synthesized using a combustion method. The photoluminescence characteristics and X-ray diffraction of the produced phosphor were studied. X-ray diffraction was used to confirm the hexagonal crystal structure with the space group P63/m (176–1). The photoluminescence characteristics of NaPb₄(PO₄)₃:Dy³⁺ phosphors measured under near-UV excitation at 350 nm showed two prominent peaks, blue and yellow emission at 470 nm and 575 nm, which were attributable to the ⁴F_9/2 → ⁶H_15/2 and ⁴F_9/2 → ⁶H_13/2 transitions of Dy³⁺ ions, respectively. The optical dopant concentration for the Dy³⁺ ions was optimized to 0.5 mol%, after which concentration quenching occurred. The photoluminescence results suggest that NaPb₄(PO₄)₃:Dy³⁺ phosphor may be used as a possible material for near-UV-based solid-state lighting.