Preparation of Ba3Si6O9N4:Eu2+ phosphor and characterization of their luminescence properties

Bluish-green Ba₃Si₆O₉N₄:Eu²⁺ phosphors were synthesized by two-step synthesis processes using BaSiO₃ as a precursor. The samples were prepared by high-temperature solid-state reaction, and investigated by X-ray diffraction (XRD) and fluorescence spectrometer photometer (PL) respectively. The results of XRD illustrated that two-step method was beneficial to improve phases of Ba₃Si₆O₉N₄:Eu²⁺ phosphor and obtain higher crystallinity. The maximum luminescent intensity of two-step process and high temperature solid-state method was obtained, when Eu²⁺ doping amount was 9%. After calculation, the distance of quenching was determined at 18.71 Å. Compared the emission spectrum of two-step process(the emission peak at 498 nm) with high-temperature solid phase method (the emission peak at 517 nm) under the excitation of 330 nm, an apparent electrophoresis of the blue shift was existed. And the emission peak of two-step process was closer to the value of theoretical (480nm). The results of energy spectrum analysis clarified that the elements content of two-step method was closer to the theoretical stoichiometry ratio, which indicated that two-step preparation of Ba₃Si₆O₉N₄:Eu²⁺ phosphor was an effective way to reduce the lattice defects.