Synthesis-temperature effect on the luminescence under light and UV excitation of Eu3+ doped lithium lanthanum borate phosphor

Abstract

Eu3+ doped lithium lanthanum borate phosphors were prepared by the solid-state reaction with different temperature in the range of 400 – 700°C. Influence of preparing temperature on the phosphor structure and luminescence property were investigated. X-ray diffraction indicates the obvious structure of monoclinic Li3La2(BO3)3 and orthorhombic LaBO3 formed in powder. Li3La2(BO3)3 was constructed better with increasing of the synthesis-temperature between 500 – 700°C. For absorption spectra, phosphor can absorb more photons in visible light and near-infrared region with the synthesis temperature rising. Visible light with 394 nm and ultraviolet with 275 nm were used to monitor the emission spectra and the strongest emission at 613 nm wavelength was founded. Powders prepared at 600 and 700°C performed the maximum intensity of emission when they were excited with mentioned ultraviolet and visible light, respectively. This difference corresponds to the variation of Li3La2(BO3)3 and LaBO3 structure via thermal synthesis. Phosphor in this work is suitable for using in the ultraviolet-light converter, display, light source and performs an interesting potential for neutron-imaging application.