Preparation of (Sr_0.5Ba_0.5)Si₂N ₂O₂: Eu²⁺ phosphor and its luminescence properties

Eu²⁺ ion-doped oxynitride phosphor, (Sr_0.5Ba _0.5)Si₂O₂- N₂:Eu²⁺, was prepared by solid-state reaction using metal alloy as precursor. Owing to the relatively high activity of the metal alloy precursor compared with the inert Si₃N₄, a single phase of solid solution phosphor (Sr _0.5Ba_0.5)Si₂O₂N₂:Eu ²⁺ was easily obtained at 1400 °C under atmospheric pressure. It showed a broad excitation band originating from the 4f⁷ → 4f⁶5d transition of Eu²⁺ ion, extending to 520 nm, and centering at 460nm and a strong emission band peaking at 565 nm. The high emission and small thermal quenching allow this material to be used for phosphor-converted white LEDs.