A new promising phosphor, Na3La2(BO3)3:Ln (Ln=Eu, Tb)

We present an efficient way to search a host for ultraviolet (UV) phosphor from UV nonlinear optical (NLO) materials. With the guidance, Na3La2(BO3)3 (NLBO), as a promising NLO material with a broad transparency range and high damage threshold, was adopted as a host material for the first time. The lanthanide ions (Tb3+ and Eu3+)-doped NLBO phosphors have been synthesized by solid-state reaction. Luminescent properties of the Ln-doped (Ln=Tb3+, Eu3+) sodium lanthanum borate were investigated under UV ray excitation. The emission spectrum was employed to probe the local environments of Eu3+ ions in NLBO crystal. For red phosphor, NLBO:Eu, the measured dominating emission peak was at 613 nm, which is attributed to 5D0–7F2 transition of Eu3+. The luminescence indicates that the local symmetry of Eu3+ in NLBO crystal lattice has no inversion center. Optimum Eu3+ concentration of NLBO:Eu3+ under UV excitation with 395 nm wavelength is about 30 mol%. The green phosphor, NLBO:Tb, showed bright green emission at 543 with 252 nm excited light. The measured concentration quenching curve demonstrated that the maximum concentration of Tb3+ in NLBO was about 20%. The luminescence mechanism of Ln-doped NLBO (Tb3+ and Eu3+) was analyzed. The relative high quenching concentration was also discussed.

An efficient way was presented to search a host for ultraviolet (UV) phosphor from UV nonlinear optical (NLO) materials. With the guidance, a new phosphor, Na3La2(BO3)3:Ln (Ln=Tb3+, Eu3+), was designed and synthesized by solid-state reaction for the first time. Eu3+ was used as luminescence probe to detect the rare earth ion doping site in the crystal lattice. The characteristics of the prepared phosphors such as excitation and emission spectra, quenching concentration of active ions, the luminescence mechanism were investigated. The results showed that Na3La2(BO3)3:Ln (Ln=Tb3+, Eu3+) may be a promising phosphors candidates for high efficiency fluorescence lamps and other related application.Figure optionsDownload as PowerPoint slide