Luminescence of Sr2SiO4-xN2x/3:Eu2+ Phosphors Prepared by Spark Plasma Sintering.

Spark plasma sintering (SPS) was employed to synthesize Sr₂SiO_3.5NO₃₃₃:Eu²⁺, Sr₂SiO₃N0₆₆₇:Eu²⁺, and Sr₂SiO₂N_1.333:Eu²⁺ for use in white light emitting diodes (LED) lightings. The SPS technique enabled a complete, rapid synthesis of these phosphors with ease, whereas it is difficult to produce nitridosilicate phosphors by any other conventional synthesis methods. The photolumines- cent (PL) spectrum of Sr₂SiO_3.5N_0.333:Eu²⁺ had two emission peaks, one at 420 and the other at 526 nm. There existed a single peak at 529 nm in the case of Sr₂SiO₃N_0.667:Eu²⁺ The PL spectrum of Sr₂SiO₂N_1.333:Eu²⁺ also had two peaks, one at 529 and the other at 600 nm. Even though the exact structure was not identified, it was revealed that the X-ray diffraction pattern of Sr₂SiO₃₅N_0.333:Eu²⁺, Sr₂SiO₃N_0.667:Eu²⁺, and Sr₂SiO₂N_1.333:Eu²⁺ was consistent with the PL data. The phosphor with the highest nitrogen content, Sr₂SiO₂N_1.333:Eu²⁺, showed a broad emission band spanning almost the entire visible range, which may work best if coupled with either UV or blue LEDs. [ABSTRACT FROM AUTHOR]