Synthesis and photoluminescence properties of Sr₂Si ₅N₈: Eu²⁺ red phosphor by a gas-reduction and nitridation method

Eu²⁺ -activated Sr₂Si₅N₈ red phosphor for white light-emitting diodes was successfully synthesized by an innovative, simple and efficient synthetic process, direct gas-reduction and nitridation of the homogeneous oxide precursor of the SrO-SiO₂- Eu₂O₃ system in the flowing N H₃ and C H ₄ mixture gas. The phase purity, morphology, and luminescence properties were investigated. The synthesized powders have a pure Sr ₂Si₅N₈ phase and consist of fine, sub-micrometer-sized particles. Under the blue light excitation, Sr ₂Si₅N₈: Eu²⁺ phosphor shows excellent luminescence properties, such as high emission intensity, high quantum efficiency, and very low thermal quenching, which is comparable to those of phosphors fabricated by the solid-state reaction method.