Luminescence enhancement of (Sr 1-x M x ) 2 SiO 4 :Eu 2 + phosphors with M (Ca 2 + /Zn 2 + ) partial substitution for white light-emitting diodes.

Eu2+-doped Sr2SiO4 phosphor with Ca2+/Zn2+ substitution, (Sr1-xMx)(2)SiO4:Eu2+ (M=Ca, Zn), was prepared using a high-temperature solid-state reaction method. The structure and luminescence properties of Ca2+/Zn2+ partially substituted Sr2SiO4:Eu2+ phosphors were investigated in detail. With Ca2+ or Zn2+ added to the silicate host, the crystal phase could be transformed between the -form and the -form of the Sr2SiO4 structure. Under UV excitation at 367nm, all samples exhibit a broad band emission from 420 to 680nm due to the 4f(6)5d(1)4f(7) transition of Eu2+ ions. The broad emission band consists of two peaks at 482 and 547nm, which correspond to Eu2+ ions occupying the ten-fold oxygen-coordinated Sr.(I) site and the nine-fold oxygen-coordinated Sr.(II) site, respectively. The luminescence properties, including the intensity and lifetime of Sr2SiO4:Eu2+ phosphors, improved remarkably on Ca2+/Zn2+ addition, and promote its application in white light-emitting diodes. Copyright (c) 2016 John Wiley & Sons, Ltd.