Preparation and characterization of Sr4Al2O7:Eu3+, Eu2+ phosphors

Abstract A new composition of red strontium aluminate phosphor (Sr 4 Al 2 O 7 :Eu 3+ , Eu 2+ ) is synthesized using a solid state reaction method in air and in a reducing atmosphere. The investigation of firing temperature indicates that a single phase of Sr 4 Al 2 O 7 is formed when the firing temperature is higher than 1300 °C and that a Sr 3 Al 2 O 6 phase is formed as the main peak below 1300 °C. The effects of firing temperature and doping concentration on luminescent properties are investigated. Sr 4 Al 2 O 7 phosphors exhibit the typical red luminescent properties of Eu 3+ and Eu 2+ . A comparison photoluminescence study with Sr 3 Al 2 O 6 phosphor shows that Sr 4 Al 2 O 7 has higher emission intensity than Sr 3 Al 2 O 6 as a result of the higher optimum doping concentration of Sr 4 Al 2 O 7 phosphor.