Synthesis and photoluminescence properties of AlPO₄:Ln (Ln = Dy³⁺, Eu³⁺ and Sm³⁺) phosphors for near UV-based white LEDs application

A series of AlPO₄:Ln (Ln = Dy³⁺, Eu³⁺ and Sm³⁺) phosphors were synthesized by the combustion technique. The phosphor's XRD and luminescent properties were thoroughly investigated. The trigonal crystal structure with the space group P 31 2 1 (152) was verified by X-ray powder diffraction. Under UV excitation (350 nm), AlPO₄:Dy³⁺ phosphor shows emission peaks at 484 and 574 nm, respectively. When AlPO₄:Eu³⁺ phosphor was excited at 395 nm, the emission spectra showed strong bands at 592 and 615 nm. When stimulated at 403 nm, the emission spectra of AlPO₄:Sm³⁺ phosphor showed an emission peak at 565 nm generated by a purely magnetic dipole, a second peak at 646 nm produced by a purely electric dipole and a third peak at 599 nm generated by both magnetic and electric dipoles, respectively. Our research showed that AlPO₄:Ln (Ln = Dy³⁺, Eu³⁺ and Sm³⁺) was a blue-yellow, orange-red, and yellow-orange-red emitting phosphor, which provides an excellent candidate for solid-state lighting, specifically for n-UV w-LED applications. (author)