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

A new composition of red strontium aluminate phosphor (Sr4Al2O7:Eu3+, Eu2+) 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 Sr4Al2O7 is formed when the firing temperature is higher than 1300 °C and that a Sr3Al2O6 phase is formed as the main peak below 1300 °C. The effects of firing temperature and doping concentration on luminescent properties are investigated. Sr4Al2O7 phosphors exhibit the typical red luminescent properties of Eu3+ and Eu2+. A comparison photoluminescence study with Sr3Al2O6 phosphor shows that Sr4Al2O7 has higher emission intensity than Sr3Al2O6 as a result of the higher optimum doping concentration of Sr4Al2O7 phosphor.