Preparation and luminescence properties of Ba3LaNa (PO4) 3F: Ce3+, Tb3+ phosphors

In this paper, the phosphate Ba3LaNa(PO4)F was chosen as the matrix, and the pure phase substance was prepared by high temperature solid-state method. A batch of Ba3LaNa(PO4)F: Ce3+ and Tb3+ phosphors was prepared, and the luminescent properties were characterized and analyzed by using relevant instruments. The single Ce3+ doped Ba3LaNa(PO4)3F phosphors exhibit a broad excitation band ranging from 230 to 330 nm which centered at 271 nm, because of the 4f-5d transition of Ce3+ ions. However, the emission spectrum can be decomposed into two Gaussian components centering at 345 and 368 nm with the excitation wavelength of 271 nm. As to the single Tb3+ doped sample, its emission spectrum displays a series of characteristic peaks of Tb3+ ions at 490, 545, 585, and 622 nm corresponding the 5D4-7FJ (J = 6, 5, 4, 3) transitions. The Ba3LaNa(PO4)F: Ce3+,Tb3+ phosphors emission peak intensity of Ce3+ ions decreases with the increasing doping concentration of Tb3+ ion and, meanwhile, the peak intensity of Tb3+ at 545 nm increases, which is all due to the energy transfer from Ce3+ to Tb3+ ions. After analysis, the mechanism of energy transfer between Ce3+ and Tb3+ ions is attributed to a dipole-dipole interaction, and the transfer efficiency can reach 58.6%, when the doping amount of Tb3+ is 0.5. From the results, the Ce3+ and Tb3+ doped Ba3LaNa(PO4)3F phosphors emitting blue-green light in near ultraviolet region are considered as an excellent material for UV-pumped LEDs.