Plasma activated synthesis and photoluminescence of red phosphor Sr2Si5N8:Eu2+

Nitrides have been widely used as red phosphors in light-emitting diodes (LEDs), but traditional synthesis methods to nitride phosphors always experience high temperature and long-time reaction processes. In this paper, the red phosphor Sr2Si5N8:Eu2+ has been synthesized by a high-efficient plasma activated synthesis (PAS) method. The effects of synthesis parameters (synthesis temperature, holding time) and the concentration of Eu2+ on crystal structures, microstructures, photoluminescence and thermal quenching properties of Sr2Si5N8:Eu2+ have been investigated. The results show that the luminous intensity of Sr2Si5N8:Eu2+ can be enhanced by improving the crystallinity, and the Sr2Si5N8:Eu2+ with high-crystallinity can be obtained under the relative lower sintering temperature of 1350 °C and very short holding time of 6 min. The photoluminence (PL) peaks are red-shift with increasing the concentration of Eu2+. Meanwhile, Sr2Si5N8:Eu2+ synthesized by PAS has more excellent thermal quenching performance and a longer fluorescent life than those synthesized by traditional solid state reaction.