Photoluminescence Properties of Novel BaLiZn₃(BO₃)₃:RE (RE = Sm³⁺, Tb³⁺, Dy³⁺, and Pb²⁺) Blue, Green, Orange-Red Emitting Phosphors for White Light Emitting Diodes

A new class of BaLiZn₃(BO₃)₃:RE (RE = Sm³⁺, Tb³⁺, Dy³⁺, and Pb²⁺) phosphors were synthesized with a solid- state reaction method. The minor concentrations of various rare earth (Tb³⁺, Dy³⁺, and Sm³⁺) ions and transition metal (Pb²⁺) ions activated in the BaLiZn₃(BO₃) host matrix were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectroscopy. The XRD results of BaLiZn₃(BO₃)3:RE (RE = Sm³⁺, Tb³⁺, Dy³⁺, and Pb²⁺) phosphors confirmed that all the samples have a monoclinic phase. SEM studies revealed that the morphology of BaLiZn₃(BO₃)₃:RE (RE = Sm³⁺, Tb³⁺, Dy³⁺, and Pb²⁺) phosphors was irregular. The photoluminescence emission and excitation spectra show that these phosphors can be effectively excited by near-ultraviolet light-emitting diodes (n-UV), and they all exhibit an efficient orange-red (Sm³⁺, ⁴G_5/2 → ⁶H_7/2), green (Tb³⁺, ⁵D₄ → ⁷F₅), yellow (Dy³⁺, ⁴F_9/2 → ⁶H_13/2), and blue (Pb²⁺, ³P₁ → ¹S₀) emission. All of the above results confirmed that the obtained phosphors could be a potential candidate for n-UV-excited WLEDs.