Blue-yellow multicolor phosphor, Eu2+-activated Li3NaSiO4: Excellent thermal stability and quenching mechanism

A multicolor emission phosphor can become a new luminescent material for emitting devices such as LEDs. However, most multicolor emission phosphors require two or more luminescent ions, such as Eu2+/Mn2+ and Eu2+/Tb3+/Mn2+. In this study, novel multicolor phosphor materials Li3NaSiO4:Eu2+ were successfully synthesized using a conventional solid-state reaction. The phosphors showed a unique white color with multicolored blue and yellow emissions under a near-ultraviolet light at 360 nm. Based on this result, there seems to be strong evidence that Eu2+ ions are substituted for two cation sites, NaO6 and LiO5. Moreover, Eu2+-doped Li3NaSiO4 phosphors exhibit excellent thermal stability in comparison with Eu2+-activated silicate phosphors owing to the presence of electron traps, which can be activated at high temperatures.