Photoluminescence properties of BaGdB9O16:Tb3+ codoped Zn2+ or Ce3+ under ultraviolet and vacuum ultraviolet excitation

Abstract

Single phase of Ba1−xZnxGd0.75Tb0.25B9O16 and BaGd0.75−xCexTb0.25B9O16 (0 ≤ x ≤ 0.125) was prepared by the solid-state reaction. Under 254 nm excitation, Zn2+ impaired the emission of Tb3+; Ce3+ sensitized the luminescence of Tb3+ ascribing to the energy transfer of Ce3+ → Tb3+ and/or Ce3+ → Gd3+ → Tb3+ occurring, and the optimum emission was observed at x = 0.05 in BaGd0.75−xCexTb0.25B9O16. Under 147 nm excitation, Zn2+ sensitized the emission of Tb3+ and the optimum emission was obtained at x = 0.075 in Ba1−xZnxGd0.75Tb0.25B9O16, which could be due to the fact that the energy absorption relating to Zn2+ occurred and the absorbed energy was transferred to Tb3+ finally; Ce3+ depressed the luminescence of Tb3+, which could be attributed to the fact that Ce3+ has no absorption in vacuum ultraviolet region and the role of Gd3+ was weakened. Compared with BaGd0.75Tb0.25B9O16 and the commercial phosphor Zn2SiO4:Mn2+, the optimum phosphor Ba0.925Zn0.075Gd0.75Tb0.25B9O16 exhibited about 127% and 51% integrated emission intensity respectively and the shorter decay time of about 2.822 ms under 147 nm excitation.