Photoluminescent properties of Sr2SiO4:Eu2+ phosphors prepared by solid-state reaction method

Sr2SiO4:Eu2+ phosphors were prepared by a flux method. Two emission bands at 495 nm and 560 nm were observed, which originated from Eu(I) and Eu(II) that were substituted for Sr(I) and Sr(II), respectively. The preference of Eu2+ ions for Sr(I) and Sr(II) strongly depended on the amounts of flux and firing temperatures. The increase of Eu2+ concentration led to the energy transfer from Eu(I) to Eu(II) emitting center, resulting in the red-shift, and the phase transformation from β- to α’-Sr2SiO4 were observed.