Synthesis and luminescent properties of hexagonal BaZnSiO₄:Eu²⁺ phosphor

A green-emitting phosphor of hexagonal BaZnSiO4:Eu2+ was prepared by a combustion-assisted synthesis method and an efficient green emission from ultraviolet to visible light was observed. The luminescence and crystallinity were investigated by using luminescence spectrometry and X-ray diffractometry. In the hexagonal structure of BaZnSiO4:Eu2+ phosphor, Eu2+ ions occupy three different lattice sites by substitution for Ba2+ ions. Eu2+ ions on Ba (1) and Ba (2) sites gave emissions at about 505 nm while Eu2+ ions on Ba (3) sites showed an emission band at 403 nm. The excitation spectrum is a broad band extending from 260 to 465 nm, which matches the emission of ultraviolet light-emitting diodes. The critical quenching concentration of Eu2+ in BaZnSiO4:Eu2+ phosphor is about 0.05 mol. The value of the critical transfer distance is calculated as 10.97 . The corresponding concentration quenching mechanism is verified to be the electric multipole-multipole interaction. The CIE coordinates of the optimized sample Ba0.95ZnSiO4:Eu-0.05(2+) were calculated as (x, y) = (0.172, 0.463).